The Ciemas gold deposit is located in West Java of Indonesia,which is a Cenozoic magmatism belt resulting from the Indo-Australian plate subducting under the Eurasian plate.Two different volcanic rock belts and associ...The Ciemas gold deposit is located in West Java of Indonesia,which is a Cenozoic magmatism belt resulting from the Indo-Australian plate subducting under the Eurasian plate.Two different volcanic rock belts and associated epithermal deposits are distributed in West Java:the younger late Miocene-Pliocene magmatic belt generated the Pliocene-Pleistocene epithermal deposits,while the older late Eocene-early Miocene magmatic belt generated the Miocene epithermal deposits.To constrain the physico-chemical conditions and the origin of the ore fluid in Ciemas,a detailed study of ore petrography,fluid inclusions,laser Raman spectroscopy,oxygen-hydrogen isotopes for quartz was conducted.The results show that hydrothermal pyrite and quartz are widespread,hydrothermal alteration is well developed,and that leaching structures such as vuggy rocks and extension structures such as comb quartz are common.Fluid inclusions in quartz are mainly liquid-rich two phase inclusions,with fluid compositions in the NaCl-H20 fluid system,and contain no or little CO_2.Their homogenization temperatures cluster around 240℃-320℃,the salinities lie in the range of 14-17 wt.%NaCl equiv,and the calculated fluid densities are 0.65-1.00 g/cm^3.The values of δ^(18)O_(H2O-VSMOW)for quartz range from +5.5‰ to +7.7‰,the δD_(VSMOW) of fluid inclusions in quartz ranges from-70‰ to-115‰.All of these data indicate that mixing of magmatic fluid with meteoric water resulted in the formation of the Ciemas deposit.A comparison among gold deposits of West Java suggests that Miocene epithermal ore deposits in the southernmost part of West Java were more affected by magmatic fluids and exhibit a higher degree of sulfldation than those of Pliocene-Pleistocene.展开更多
Arroyo Verde epithermal deposit,in the North Patagonia region of Argentina,is located within the Lower Chon Aike volcanism and is developed between 192.6±2.5 Ma(mineralization host rock)and 189.5±2.6 Ma(over...Arroyo Verde epithermal deposit,in the North Patagonia region of Argentina,is located within the Lower Chon Aike volcanism and is developed between 192.6±2.5 Ma(mineralization host rock)and 189.5±2.6 Ma(overlying lava).Marifil volcanic complex is the host rock for these veins,veinlets and breccias.This particular small deposit has developed low to intermediate sulphidation characteristics,with gangue mineral textures associated with several ore minerals.Electron probe microanalysis determines electrum,silver minerals such as acanthite,and tetrahedrite,related Ag-Cu minerals like jalpaite,mckinstryite,stromeyerite,and base metals like chalcopyrite,sphalerite,galena and pyrite.Fluid inclusions in quartz of two out of five events indicate that these Low Jurassic veins were formed due to subtle boiling and dilution mechanisms and by low-salinity(3.4 wt.%to 6.7 wt.%NaCl Eq)magmatic-hydrothermal fluid at 225 to 310℃.The fluid inclusion measurements that indicate boiling(Event 3)were plotted,and based on this data,we interpret that the Arroyo Verde deposit has been eroded between 550 and 700 m.This particular character has not been previously recorded for other sectors of the eastern north Patagonian region.展开更多
The Xinlong gold deposit is located in Niyma County,Naqu area of Tibet and was discovered by the Institute of Mineral Resources,Chinese Academy of Geological Sciences through the 1∶50000 mineral geological survey.The...The Xinlong gold deposit is located in Niyma County,Naqu area of Tibet and was discovered by the Institute of Mineral Resources,Chinese Academy of Geological Sciences through the 1∶50000 mineral geological survey.The ore bodies occur in the Zenong Group volcanic rocks in the middle section of the central Lhasa subterrane and are structurally controlled by the NNW-striking faults.Four ore bodies have been found,exhibiting cloddy,dense-sparse,disseminated,and breccia structures.The ore minerals are mainly tetrahedrite group minerals,and other ore minerals include pyrite,chalcopyrite,nevskite,bornite,anglesite,native gold,and silver-gold bearing selenide,etc.The types of alteration are dominated by silicification,as well as middle-and high-graded argillization.The alteration mineral assemblages contain quzrtz,pyrophyllite,and kaolinite.The Zaliela Formation volcanic rocks of Zenong Group are silicified by later hydrothermal fluid with vuggy quartz in some fractured zones.The middle-and high-graded argillization are characterized by pyrophyllitization and kaolinization.The Xinlong gold deposit shows great metallogenetic potentiality and has been revealed by 1∶10000 geological mapping,IP sounding,and trial trenching in the mining area.Combined with the regional metallogenic geological setting,we suppose that a potential epithermal gold belt probably exists in the middle of the Lhasa terrane.The discovery of the Xinlong gold deposit opens a new chapter for the gold prospecting in Northern Tibet.展开更多
Oxygen fugacity(fO_(2))is a key intensity variable during the entire magmatic-hydrothermal mineralization courses.The redox state and its variations between different stages of the ore-forming fluids of intermediate s...Oxygen fugacity(fO_(2))is a key intensity variable during the entire magmatic-hydrothermal mineralization courses.The redox state and its variations between different stages of the ore-forming fluids of intermediate sulfidation epithermal deposits are rarely deciphered due to the lack of appropriate approaches to determine fO_(2)of the fluids.Here,we reported theδ^(34)S of the sulfides from three different stages(stageⅠ,Ⅱ,Ⅲ)of Zhengguang,an Early Ordovician Au-rich intermediate sulfidation(IS)epithermal deposit,to decipher the redox evolution of the ore-forming fluids.The increasingδ^(34)S values from stageⅠpyrite(pyl,average-2.6‰)through py2(average-1.9‰)to py3(average-0.2‰)indicates a decrease of the oxygen fugacity of the ore-forming fluids.A compilation ofδ^(34)S values of sulfides from two subtypes of IS deposits(Au-rich and Ag-rich)from NE China shows that theδ^(34)S values of sulfides from Au-rich IS deposits are systematically lighter than those of Ag-rich IS Ag-Pb-Zn deposit,indicating the ore-forming fluids of the former are more oxidized than the latter.We highlight that sulfur isotopic composition of hypogene sulfides is an efficacious proxy to fingerprint the oxygen fugacity fluctuations of epithermal deposits and could potentially be used to distinguish the subtypes of IS deposits.展开更多
1.Objective The Fankou giant zinc(Zn)-lead(Pb)deposit in Guangdong Province is well-known for its huge reserves of over 10 Mt(million ton)Zn+Pb metals and high ore-grade with Zn+Pb exceeding 15%(Guangdong Fankou Depos...1.Objective The Fankou giant zinc(Zn)-lead(Pb)deposit in Guangdong Province is well-known for its huge reserves of over 10 Mt(million ton)Zn+Pb metals and high ore-grade with Zn+Pb exceeding 15%(Guangdong Fankou Deposit Investigation Group,1980;Zhu XY et al.,2017).After 60 years of exploration and exploitation,the deposit has accumulated millions of tons of tailings.One interesting question is that what components are hosted in these tailings,and whether some key and critical metals such as gallium and germanium are extremely enriched and worth further comprehensive utilization.This motivated us to conduct an integrated set of field investigation,sampling,major-trace element analyses and reserve assessments about the Fankou tailings.In this contribution,we discover that the tailings contain a variety of metal elements such as zinc,lead and gallium with comprehensive utilization potential.These data can act as a scientific guidance for further exploration and utilization of the Fankou tailings,and aid to enhance the utilization efficiency of the key mineral resource in China.Our study also provide demonstration for future green mine construction in China.展开更多
The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,w...The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,west of the Baimashan granitic batholith.In order to discern the characteristics of the ore-formingfluids,the underlying mineralization processes,and establish a foundation for the origin of the Yueguang gold depositfluid inclusion micro-thermometry,as well as quartz hydrogen and oxygen isotope analysis,have been carried out on samples obtained from various stages of mineralization.The hydrothermal miner-alization stages within the Yueguang gold deposit can be categorized into three stages:(i)the barren,pre-ore quartz-pyrite stage(Stage Ⅰ),the quartz-pyrite-gold stage(Stage Ⅱ),and the post-ore quartz-carbonate stage(Stage Ⅲ),with the second stage being the main mineralization stage.Thefluid inclusions identified in samples from the main min-eralization stage can predominantly be described with the NaCl–H_(2)O and CO_(2)–NaCl–H_(2)O systems.These inclusions display homogenization temperatures ranging from 158.8 to 334.9℃,and thefluid salinity ranges from 0.3%to 4.0%(wt.%NaCl equiv.).Laser Raman spectroscopy analysis of individual inclusions further reveals the presence of gas-phases such as CO_(2),CH_(4),and N_(2).Isotopic analysis indicatesδ^(18)Ofluid values ranging from 3.95 to 6.7‰ and δDH_(2)O values ranging from-71.9 to-55.7‰.These results indi-cate that the ore-formingfluid of the Yueguang gold deposit belongs to metamorphic hydrothermalfluids of middle-low temperature and low salinity.In the process of ore formation,gold is transported in the form of Au(HS)2-complexes,with gold deposition being driven byfluid immiscibility.Therefore,the Yueguang gold deposit is categorized as an orogenic gold deposit dominated by metamorphic hydrother-malfluid.It may become a new target for gold exploration in the Baimashan region,central Hunan Province.展开更多
Pellet injection is a primary method for fueling the plasma in magnetic confinement devices.For that goal the knowledges of pellet ablation and deposition profiles are critical.In the present study,the pellet fueling ...Pellet injection is a primary method for fueling the plasma in magnetic confinement devices.For that goal the knowledges of pellet ablation and deposition profiles are critical.In the present study,the pellet fueling code HPI2 was used to predict the ablation and deposition profiles of deuterium pellets injected into a typical H-mode discharge on the EAST tokamak.Pellet ablation and deposition profiles were evaluated for various pellet injection locations,with the aim at optimizing the pellet injection to obtain a deep fueling depth.In this study,we investigate the effect of the injection angle on the deposition depth of the pellet at different velocities and sizes.The ablation and deposition of the injected pellet are mainly studied at each injection position for three different injection angles:0°,45°,and 60°.The pellet injection on the high field side(HFS)can achieve a more ideal deposition depth than on the low field side(LFS).Among these angles,horizontal injection on the middle plane is relatively better on either the HFS or the LFS.When the injection location is 0.468 m below the middle plane on the HFS or 0.40 m above the middle plane of the LFS,it can achieve a similar deposition depth to the one of its corresponding side.When the pre-cooling effect is taken into account,the deposition depth is predicted to increase only slightly when the pellet is launched from the HFS.The findings of this study will serve as a reference for the update of pellet injection systems for the EAST tokamak.展开更多
Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low temperatures.Reducing hydrate adhesion on pipelines is viewed as an efficient way to prevent N...Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low temperatures.Reducing hydrate adhesion on pipelines is viewed as an efficient way to prevent NGH blockages.Previous studies suggested the water film can greatly increase hydrate adhesion in gas-dominant system.Herein,by performing the molecular dynamics simulations,we find in water-dominant system,the water film plays different roles in hydrate deposition on Fe and its corrosion surfaces.Specifically,due to the strong affinity of water on Fe surface,the deposited hydrate cannot convert the adsorbed water into hydrate,thus,a water film exists.As water affinities decrease(Fe>Fe_(2)O_(3)>FeO>Fe_(3)O_(4)),adsorbed water would convert to amorphous hydrate on Fe_(2)O_(3)and form the ordered hydrate on FeO and Fe_(3)O_(4)after hydrate deposition.While absorbed water film converts to amorphous or to hydrate,the adhesion strength of hydrate continuously increases(Fe<Fe_(2)O_(3)<FeO<Fe_(3)O_(4)).This is because the detachment of deposited hydrate prefers to occur at soft region of liquid layer,the process of which becomes harder as liquid layer vanishes.As a result,contrary to gas-dominant system,the water film plays the weakening roles on hydrate adhesion in water-dominant system.Overall,our results can help to better understand the hydrate deposition mechanisms on Fe and its corrosion surfaces and suggest hydrate deposition can be adjusted by changing water affinities on pipeline surfaces.展开更多
Lamprophyres typically appear in hydrothermal gold deposits.The relationship between lamprophyres and gold deposits is investigated widely.Some researchers suggest that the emplacement of lamprophyres triggers gold mi...Lamprophyres typically appear in hydrothermal gold deposits.The relationship between lamprophyres and gold deposits is investigated widely.Some researchers suggest that the emplacement of lamprophyres triggers gold mineralization,whereas others hypothesize that the formation of lamprophyres increases the fertility of mantle sources and ore-forming fluids.K-feldspar veins,with ages between those of lamprophyres and gold deposits,appear in lamprophyres in Zhenyuan.Therefore,K-feldspar veins are ideal for investigating the relationship between lamprophyres and gold deposits.Phlogopite in K-feldspar veins has lower Mg#,Ni,and Cr contents and higher TiO2,Li,Ba,Sr,Sc,Zr,Nb,and Cs contents than phlogopite in lamprophyres.The in-situ Sr isotopic values of apatites(0.7063–0.7066)in K-feldspar veins are within the range for apatites(0.7064–0.7078)from lamprophyres.High large-ion lithophile element concentrations and low Nb and Ta concentrations in phlogopite from lamprophyres,in addition to high(87Sr/86Sr)i values of apatite(0.7064–0.7078),indicate that the magma parental to these phlogopite and apatite crystals is derived from an enriched mantle.Kfeldspar veins are genetically correlated with lamprophyres,whereas sulfide mineral assemblage and trace element compositions of pyrite in K-feldspar veins suggest that K-feldspar veins in lamprophyres are not directly related to gold mineralization of the Zhenyuan deposit.展开更多
This paper proposes a type of double-layer charge liner fabricated using chemical vapor deposition(CVD)that has tungsten as its inner liner.The feasibility of this design was evaluated through penetration tests.Double...This paper proposes a type of double-layer charge liner fabricated using chemical vapor deposition(CVD)that has tungsten as its inner liner.The feasibility of this design was evaluated through penetration tests.Double-layer charge liners were fabricated by using CVD to deposit tungsten layers on the inner surfaces of pure T2 copper liners.The microstructures of the tungsten layers were analyzed using a scanning electron microscope(SEM).The feasibility analysis was carried out by pulsed X-rays,slug-retrieval test and static penetration tests.The shaped charge jet forming and penetration law of inner tungsten-coated double-layer liner were studied by numerical simulation method.The results showed that the double-layer liners could form well-shaped jets.The errors between the X-ray test results and the numerical results were within 11.07%.A slug-retrieval test was found that the retrieved slug was similar to a numerically simulated slug.Compared with the traditional pure copper shaped charge jet,the penetration depth of the double-layer shaped charge liner increased by 11.4% and>10.8% respectively.In summary,the test results are good,and the numerical simulation is in good agreement with the test,which verified the feasibility of using the CVD method to fabricate double-layer charge liners with a high-density and high-strength refractory metal as the inner liner.展开更多
Tumor deposits(TDs)are defined as discrete,irregular clusters of tumor cells lying in the soft tissue adjacent to but separate from the primary tumor,and are usually found in the lymphatic drainage area of the primary...Tumor deposits(TDs)are defined as discrete,irregular clusters of tumor cells lying in the soft tissue adjacent to but separate from the primary tumor,and are usually found in the lymphatic drainage area of the primary tumor.By definition,no residual lymph node structure should be identified in these tumor masses.At present,TDs are mainly reported in colorectal cancer,with a few reports in gastric cancer.There are very few reports on breast cancer(BC).For TDs,current dominant theories suggest that these are the result of lymph node metastasis of the tumor with complete destruction of the lymph nodes by the tumor tissue.Even some pathologists classify a TD as two lymph node metastases for calculation.Some pathologists also believe that TDs belong to the category of disseminated metastasis.Therefore,regardless of the origin,TDs are an indicator of poor prognosis.Moreover,for BC,sentinel lymph node biopsy is generally used at present.Whether radical axillary lymph node dissection should be adopted for BC with TDs in axillary lymph nodes is still inconclusive.The present commentary of this clinical issue has certain guiding significance.It is aimed to increase the awareness of the scientific community towards this under-recognized problem in BC pathology.展开更多
By studying the light isotopic compositions of carbon,oxygen,and hydrogen,combined with previous research results on the ore-forming source of the deposit,the authors try to uncover its metallogenic origin.The δ^(18)...By studying the light isotopic compositions of carbon,oxygen,and hydrogen,combined with previous research results on the ore-forming source of the deposit,the authors try to uncover its metallogenic origin.The δ^(18)O and δ^(13)C isotope signatures of dolomite samples vary between 10.2 and 13.0‰,and between−7.2 and−5.2‰,respectively,implying that the carbon derives from the upper mantle.δD and δ^(18) O of quartz,biotite,and muscovite from diff erent ore veins of the deposit vary between−82 and−59‰,and between 11.6 and 12.4‰,respectively,implying that the metallogenic solutions are mainly magmatic.According to the relevant research results of many isotope geologists,the fractionation degree of hydrogen isotopes increases as the depth to the Earth’s core increases,and the more diff erentiated the hydrogen isotopes are,the lower their values will be.In other words,mantle-derived solutions can have extremely low hydrogen isotope values.This means that the δD‰ value−134 of the pyrrhotite sample numbered SD-34 in this article may indicate mantle-derived oreforming fl uid of the deposit.The formation of the Dashuigou tellurium deposit occurred between 91.71 and 80.19 Ma.展开更多
Aviation turbine engine oils require excellent thermal-oxidative stability because of their high-temperature environments.High-temperature bearing deposit testing is a mandatory method for measuring the thermal-oxidat...Aviation turbine engine oils require excellent thermal-oxidative stability because of their high-temperature environments.High-temperature bearing deposit testing is a mandatory method for measuring the thermal-oxidative performance of aviation lubricant oils,and the relevant apparatus was improved in the present study.Two different commercial aviation turbine engine oils were tested,one with standard performance(known as the SL oil)and the other with high thermal stability,and their thermal-oxidative stability characteristics were evaluated.After 100 h of high-temperature bearing testing,the SL oil was analyzed by using various analytical techniques to investigate its thermal-oxidative process in the bearing test,with its thermal-oxidative degradation mechanism also being discussed.The results indicate that the developed high-temperature bearing apparatus easily meets the test requirements of method 3410.1 in standard FED-STD-791D.The viscosity and total acid number(TAN)of the SL oil increased with the bearing test time,and various deposits were produced in the bearing test,with the micro-particles of the carbon deposits being sphere-like,rod-like,and sheet-like in appearance.The antioxidant additives in the oil were consumed very rapidly in the first 30 h of the bearing test,with N-phenyl-1-naphthylamine being consumed faster than dioctyldiphenylamine.Overall,the oil thermal-oxidative process involves very complex physical and chemical mechanisms.展开更多
Asphaltene deposition is a significant problem during gas injection processes,as it can block the porous medium,the wellbore,and the involved facilities,significantly impacting reservoir productivity and ultimate oil re...Asphaltene deposition is a significant problem during gas injection processes,as it can block the porous medium,the wellbore,and the involved facilities,significantly impacting reservoir productivity and ultimate oil recovery.Only a few studies have investigated the numerical modeling of this potential effect in porous media.This study focuses on asphaltene deposition due to natural gas and CO_(2) injection.Predictions of the effect of gas injection on asphaltene deposition behavior have been made using a 3D numerical simulation model.The results indicate that the injection of natural gas exacerbates asphaltene deposition,leading to a significant reduction in permeability near the injection well and throughout the reservoir.This reduction in permeability strongly affects the ability of gas toflow through the reservoir,resulting in an improvement of the displacement front.The displacement effi-ciency of the injection gas process increases by up to 1.40%when gas is injected at 5500 psi,compared to the scenario where the asphaltene model is not considered.CO_(2) injection leads to a miscible process with crude oil,extracting light and intermediate components,which intensifies asphaltene precipitation and increases the viscosity of the remaining crude oil,ultimately reducing the recovery rate.展开更多
The Ain El Bey abandoned mine, in North-West Tunisia, fits into the geodynamic context of the European and African plate boundary. Ore deposit corresponds to veins and breccia of multiphase Cu–Fe-rich mineralization ...The Ain El Bey abandoned mine, in North-West Tunisia, fits into the geodynamic context of the European and African plate boundary. Ore deposit corresponds to veins and breccia of multiphase Cu–Fe-rich mineralization related to various hydrothermal fluid circulations. Petromineralogical studies indicate a rich mineral paragenesis with a minimum of seven mineralization phases and, at least, six pyrite generations. As is also the case for galena and native silver, native gold is observed for the first time as inclusion in quartz which opens up, thus, new perspectives for prospecting and evaluating the potential for noble metals associated with the mineralization. Scanning Electron Microscope--Energy Dispersive Spectroscopy and Transmission electron microscopy analyses show, in addition, a large incorporation of trace elements, including Ag and Au, in mineral structures such as fahlores(tetrahedrite-tennantite) and chalcopyrite ones. The mineral/mineral associations, used as geothermometers, gave estimated temperatures for the mineralizing fluids varying from 254 to 330 ℃ for phase Ⅲ, from 254 to 350 ℃ for phase Ⅳ, and from 200 to 300 ℃ for phases Ⅴ and Ⅵ. The seventh and last identified mineralization phase, marked by a deposit of native gold, reflects a drop in the mineralizing fluid’s temperature(< 200 ℃) compatible with boiling conditions. Such results open up perspectives for the development of precious metal research and the revaluation of the Cu–Fe ore deposit at the Ain El Bey abandoned mine, as well as at the surrounding areas fitting in the geodynamic framework of the Africa-Europe plate boundary.展开更多
Solid polymer electrolyte(SPE) shows great potential for all-solid-state batteries because of the inherent safety and flexibility;however, the unfavourable Li+deposition and large thickness hamper its development and ...Solid polymer electrolyte(SPE) shows great potential for all-solid-state batteries because of the inherent safety and flexibility;however, the unfavourable Li+deposition and large thickness hamper its development and application. Herein, a laminar MXene functional layer-thin SPE layer-cathode integration(MXene-PEO-LFP) is designed and fabricated. The MXene functional layer formed by stacking rigid MXene nanosheets imparts higher compressive strength relative to PEO electrolyte layer. And the abundant negatively-charged groups on MXene functional layer effectively repel anions and attract cations to adjust the charge distribution behavior at electrolyte–anode interface. Furthermore,the functional layer with rich lithiophilic groups and outstanding electronic conductivity results in low Li nucleation overpotential and nucleation energy barrier. In consequence, the cell assembled with MXene-PEO-LFP, where the PEO electrolyte layer is only 12 μm, much thinner than most solid electrolytes, exhibits uniform, dendrite-free Li+deposition and excellent cycling stability. High capacity(142.8 mAh g-1), stable operation of 140 cycles(capacity decay per cycle, 0.065%), and low polarization potential(0.5 C) are obtained in this Li|MXene-PEO-LFP cell,which is superior to most PEO-based electrolytes under identical condition. This integrated design may provide a strategy for the large-scale application of thin polymer electrolytes in all-solid-state battery.展开更多
Dust deposition on the surface of photovoltaic (PV) cells poses a significant challenge to their efficiency, especially in arid regions characterized by desert and semi-desert conditions. Despite the pronounced impact...Dust deposition on the surface of photovoltaic (PV) cells poses a significant challenge to their efficiency, especially in arid regions characterized by desert and semi-desert conditions. Despite the pronounced impact of dust accumulation, these regions offer optimal solar radiation and minimal cloud cover, making them ideal candidates for widespread PV cell deployment. Various surface cleaning methods exist, each employing distinct approaches. Choosing an appropriate cleaning method requires a comprehensive understanding of the mechanisms involved in both dust deposition on module surfaces and dust adhesion to PV cell surfaces. The mechanisms governing dust deposition and adhesion are complex and multifaceted, influenced by factors such as the nature and properties of the dust particles, environmental climatic conditions, characteristics of protective coatings, and the specific location of the PV installation. These factors exhibit regional variations, necessitating the implementation of diverse cleaning approaches tailored to the unique conditions of each location. The first part of this article explores the factors influencing dust deposition on PV cell surfaces, delving into the intricate interplay of environmental variables and particle characteristics. Subsequently, the second part addresses various cleaning methods, offering an analysis of their respective advantages and disadvantages. By comprehensively examining the factors influencing dust accumulation and evaluating the effectiveness of different cleaning strategies, this article aims to contribute valuable insights to the ongoing efforts to optimize the performance and longevity of photovoltaic systems in diverse geographical contexts.展开更多
Background: To explore the effects of electroacupuncture on cardiac function and myocardial fibrosis in rat models of heart failure, and to elucidate the underlying mechanism of electroacupuncture in heart failure tre...Background: To explore the effects of electroacupuncture on cardiac function and myocardial fibrosis in rat models of heart failure, and to elucidate the underlying mechanism of electroacupuncture in heart failure treatment. Methods: Healthy male Sprague-Dawley rats were allocated into three groups: Sham group, Model group, and electroacupuncture (Model + EA) group, with each group comprising 8 rats. The model underwent a procedure involving the ligation of the left anterior descending coronary artery to induce a model of heart failure. The Model + EA group was used for 7 consecutive days for electroacupuncture of bilateral Shenmen (HT7) and Tongli (HT5), once a day for 30 min each time. Left ventricular parameters in rats were assessed using a small-animal ultrasound machine to analyze changes in left ventricular end-diastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction, and left ventricular fractional shortening. Serum interleukin-1β (IL-1β), cardiac troponin (cTn), and N-terminal brain natriuretic peptide precursor levels were measured using ELISA. Histopathological changes in rat myocardium were observed through HE staining, while collagen deposition in rat myocardial tissue was assessed using the Masson staining method. Picro sirius red staining, immunohistochemical staining, and RT-qPCR were utilized to distinguish between the various types of collagen deposition. The expression level of TGF-β1 and SMAD2/3/4/7 mRNA in rat myocardial tissues was determined using RT-qPCR. Additionally, western blot analysis was conducted to assess the protein expression levels of TGF-β1, SMAD3/7, and p-SMAD3 in rat myocardial tissues. Results: Compared with the Sham group, the left ventricular ejection fraction and left ventricular fractional shortening values of the Model group were significantly decreased (P < 0.01);the left ventricular end-diastolic volume and left ventricular end-systolic volume values were remarkably increased (P < 0.01);serum N-terminal brain natriuretic peptide precursor content was increased (P < 0.01);serum IL-1β and cTn levels were increased (P < 0.01);myocardial collagen volume fraction were increased (P < 0.01);and those of the expression of TGF-β1 and SMAD2/3/4 mRNA was increased (P < 0.01);the expression of SMAD7 mRNA was decreased (P < 0.01);the protein expression levels of TGF-β1, SMAD3, and p-Smad3 were increased (P < 0.01);the protein expression level of SMAD7 was decreased (P < 0.01) in the Model group. Compared to the Model group, the expression levels of the proteins TGF-β1, SMAD3, and p-Smad3 in myocardial tissue were found to be decreased (P < 0.01), and the expression level of the protein SMAD7 was found to be increased (P < 0.01) in the Model + EA group;the collagen volume fraction and deposition of type Ⅰ /Ⅲ collagen were decreased (P < 0.01) in the Model + EA group. Conclusion: Electroacupuncture alleviates myocardial fibrosis in rats with heart failure, and this effect is likely due to attributed to the modulation of the TGF-β1/Smads signaling pathway, which helps reduce collagen deposition in the extracellular matrix.展开更多
Graphene(Gr)has unique properties including high electrical conductivity;Thus,graphene/copper(Gr/Cu)composites have attracted increasing attention to replace traditional Cu for electrical applications. However,the pro...Graphene(Gr)has unique properties including high electrical conductivity;Thus,graphene/copper(Gr/Cu)composites have attracted increasing attention to replace traditional Cu for electrical applications. However,the problem of how to control graphene to form desired Gr/Cu composite is not well solved. This paper aims at exploring the best parameters for preparing graphene with different layers on Cu foil by chemical vapor deposition(CVD)method and studying the effects of different layers graphene on Gr/Cu composite’s electrical conductivity. Graphene grown on single-sided and double-sided copper was prepared for Gr/Cu and Gr/Cu/Gr composites. The resultant electrical conductivity of Gr/Cu composites increased with decreasing graphene layers and increasing graphene volume fraction. The Gr/Cu/Gr composite with monolayer graphene owns volume fraction of less than 0.002%,producing the best electrical conductivity up to59.8 ×10^(6)S/m,equivalent to 104.5% IACS and 105.3% pure Cu foil.展开更多
In the light of field investigation, microscopic study, X\|ray phase analysis and mineral infrared spectral analysis, it is considered that laumontitization is of extensive occurrence in the Axi gold orefield. The dev...In the light of field investigation, microscopic study, X\|ray phase analysis and mineral infrared spectral analysis, it is considered that laumontitization is of extensive occurrence in the Axi gold orefield. The development of laumontitization and its relationship to mineralization show that the laumontitization appeared mainly at the top of and in the periphery of orebodies, and occurred at the edge of the epithermal system or at the late stage of epithermal system evolution. Therefore, laumontitization can be used as an exploration indicator of epithermal gold deposits. The fluids responsible for laumontitization in the Axi gold orefield are similar to those producing hot spring\|type gold deposits or those from modern geothermal fields. Epithermal mineralization of the Axi gold deposit was dated at Carboniferous, indicating that the West Tianshan of China is a region favorable to epithermal\|type gold mineralization and preservation. Hence the West Tianshan of China is a target area for exploring epithermal gold deposits.展开更多
基金financially supported by the National Natural Science Foundation of China(NFSC No. 41573039)
文摘The Ciemas gold deposit is located in West Java of Indonesia,which is a Cenozoic magmatism belt resulting from the Indo-Australian plate subducting under the Eurasian plate.Two different volcanic rock belts and associated epithermal deposits are distributed in West Java:the younger late Miocene-Pliocene magmatic belt generated the Pliocene-Pleistocene epithermal deposits,while the older late Eocene-early Miocene magmatic belt generated the Miocene epithermal deposits.To constrain the physico-chemical conditions and the origin of the ore fluid in Ciemas,a detailed study of ore petrography,fluid inclusions,laser Raman spectroscopy,oxygen-hydrogen isotopes for quartz was conducted.The results show that hydrothermal pyrite and quartz are widespread,hydrothermal alteration is well developed,and that leaching structures such as vuggy rocks and extension structures such as comb quartz are common.Fluid inclusions in quartz are mainly liquid-rich two phase inclusions,with fluid compositions in the NaCl-H20 fluid system,and contain no or little CO_2.Their homogenization temperatures cluster around 240℃-320℃,the salinities lie in the range of 14-17 wt.%NaCl equiv,and the calculated fluid densities are 0.65-1.00 g/cm^3.The values of δ^(18)O_(H2O-VSMOW)for quartz range from +5.5‰ to +7.7‰,the δD_(VSMOW) of fluid inclusions in quartz ranges from-70‰ to-115‰.All of these data indicate that mixing of magmatic fluid with meteoric water resulted in the formation of the Ciemas deposit.A comparison among gold deposits of West Java suggests that Miocene epithermal ore deposits in the southernmost part of West Java were more affected by magmatic fluids and exhibit a higher degree of sulfldation than those of Pliocene-Pleistocene.
文摘Arroyo Verde epithermal deposit,in the North Patagonia region of Argentina,is located within the Lower Chon Aike volcanism and is developed between 192.6±2.5 Ma(mineralization host rock)and 189.5±2.6 Ma(overlying lava).Marifil volcanic complex is the host rock for these veins,veinlets and breccias.This particular small deposit has developed low to intermediate sulphidation characteristics,with gangue mineral textures associated with several ore minerals.Electron probe microanalysis determines electrum,silver minerals such as acanthite,and tetrahedrite,related Ag-Cu minerals like jalpaite,mckinstryite,stromeyerite,and base metals like chalcopyrite,sphalerite,galena and pyrite.Fluid inclusions in quartz of two out of five events indicate that these Low Jurassic veins were formed due to subtle boiling and dilution mechanisms and by low-salinity(3.4 wt.%to 6.7 wt.%NaCl Eq)magmatic-hydrothermal fluid at 225 to 310℃.The fluid inclusion measurements that indicate boiling(Event 3)were plotted,and based on this data,we interpret that the Arroyo Verde deposit has been eroded between 550 and 700 m.This particular character has not been previously recorded for other sectors of the eastern north Patagonian region.
基金funded by the National Natural Science Foundation of China(41902099)the China Geological Survey Project(DD20230054)Fundamental Research Funds from the Institute of Mineral Resources and Chinese Academy of Geological Sciences(No.KK2215).
文摘The Xinlong gold deposit is located in Niyma County,Naqu area of Tibet and was discovered by the Institute of Mineral Resources,Chinese Academy of Geological Sciences through the 1∶50000 mineral geological survey.The ore bodies occur in the Zenong Group volcanic rocks in the middle section of the central Lhasa subterrane and are structurally controlled by the NNW-striking faults.Four ore bodies have been found,exhibiting cloddy,dense-sparse,disseminated,and breccia structures.The ore minerals are mainly tetrahedrite group minerals,and other ore minerals include pyrite,chalcopyrite,nevskite,bornite,anglesite,native gold,and silver-gold bearing selenide,etc.The types of alteration are dominated by silicification,as well as middle-and high-graded argillization.The alteration mineral assemblages contain quzrtz,pyrophyllite,and kaolinite.The Zaliela Formation volcanic rocks of Zenong Group are silicified by later hydrothermal fluid with vuggy quartz in some fractured zones.The middle-and high-graded argillization are characterized by pyrophyllitization and kaolinization.The Xinlong gold deposit shows great metallogenetic potentiality and has been revealed by 1∶10000 geological mapping,IP sounding,and trial trenching in the mining area.Combined with the regional metallogenic geological setting,we suppose that a potential epithermal gold belt probably exists in the middle of the Lhasa terrane.The discovery of the Xinlong gold deposit opens a new chapter for the gold prospecting in Northern Tibet.
基金jointly funded by the National Natural Science Foundation of China(Grant Nos.42202085,42272080)China Postdoctoral Science Foundation(Grant Nos.2020M680666,2021T140660)+1 种基金postdoctoral program of China Scholarship Council(Grant No.202104910161)National Key Research and Development Program of China(Grant No.2017YFC0601305)。
文摘Oxygen fugacity(fO_(2))is a key intensity variable during the entire magmatic-hydrothermal mineralization courses.The redox state and its variations between different stages of the ore-forming fluids of intermediate sulfidation epithermal deposits are rarely deciphered due to the lack of appropriate approaches to determine fO_(2)of the fluids.Here,we reported theδ^(34)S of the sulfides from three different stages(stageⅠ,Ⅱ,Ⅲ)of Zhengguang,an Early Ordovician Au-rich intermediate sulfidation(IS)epithermal deposit,to decipher the redox evolution of the ore-forming fluids.The increasingδ^(34)S values from stageⅠpyrite(pyl,average-2.6‰)through py2(average-1.9‰)to py3(average-0.2‰)indicates a decrease of the oxygen fugacity of the ore-forming fluids.A compilation ofδ^(34)S values of sulfides from two subtypes of IS deposits(Au-rich and Ag-rich)from NE China shows that theδ^(34)S values of sulfides from Au-rich IS deposits are systematically lighter than those of Ag-rich IS Ag-Pb-Zn deposit,indicating the ore-forming fluids of the former are more oxidized than the latter.We highlight that sulfur isotopic composition of hypogene sulfides is an efficacious proxy to fingerprint the oxygen fugacity fluctuations of epithermal deposits and could potentially be used to distinguish the subtypes of IS deposits.
基金supported by the National Key Research and Development Program of China(2021YFC2900300)the National Natural Science Foundation of China(42022020 and 41872193)+1 种基金the Guangdong Province Introduced of Innovative R&D Team(2021ZT09H399)the Zhongjin Lingnan Fankou Lead-zinc Mine Enterprise Entrusted Project(2022.J005).
文摘1.Objective The Fankou giant zinc(Zn)-lead(Pb)deposit in Guangdong Province is well-known for its huge reserves of over 10 Mt(million ton)Zn+Pb metals and high ore-grade with Zn+Pb exceeding 15%(Guangdong Fankou Deposit Investigation Group,1980;Zhu XY et al.,2017).After 60 years of exploration and exploitation,the deposit has accumulated millions of tons of tailings.One interesting question is that what components are hosted in these tailings,and whether some key and critical metals such as gallium and germanium are extremely enriched and worth further comprehensive utilization.This motivated us to conduct an integrated set of field investigation,sampling,major-trace element analyses and reserve assessments about the Fankou tailings.In this contribution,we discover that the tailings contain a variety of metal elements such as zinc,lead and gallium with comprehensive utilization potential.These data can act as a scientific guidance for further exploration and utilization of the Fankou tailings,and aid to enhance the utilization efficiency of the key mineral resource in China.Our study also provide demonstration for future green mine construction in China.
基金support from several sources,including the Backbone Teacher Training Program(10912-SJGG2021-04233)the Teaching Reform Project of Chengdu University of Technology(JG2130131)+1 种基金the University-Industry Collaborative Education Project,Ministry of Education,China(22097130210756)National Natural Science Foundation of China(42272129).
文摘The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,west of the Baimashan granitic batholith.In order to discern the characteristics of the ore-formingfluids,the underlying mineralization processes,and establish a foundation for the origin of the Yueguang gold depositfluid inclusion micro-thermometry,as well as quartz hydrogen and oxygen isotope analysis,have been carried out on samples obtained from various stages of mineralization.The hydrothermal miner-alization stages within the Yueguang gold deposit can be categorized into three stages:(i)the barren,pre-ore quartz-pyrite stage(Stage Ⅰ),the quartz-pyrite-gold stage(Stage Ⅱ),and the post-ore quartz-carbonate stage(Stage Ⅲ),with the second stage being the main mineralization stage.Thefluid inclusions identified in samples from the main min-eralization stage can predominantly be described with the NaCl–H_(2)O and CO_(2)–NaCl–H_(2)O systems.These inclusions display homogenization temperatures ranging from 158.8 to 334.9℃,and thefluid salinity ranges from 0.3%to 4.0%(wt.%NaCl equiv.).Laser Raman spectroscopy analysis of individual inclusions further reveals the presence of gas-phases such as CO_(2),CH_(4),and N_(2).Isotopic analysis indicatesδ^(18)Ofluid values ranging from 3.95 to 6.7‰ and δDH_(2)O values ranging from-71.9 to-55.7‰.These results indi-cate that the ore-formingfluid of the Yueguang gold deposit belongs to metamorphic hydrothermalfluids of middle-low temperature and low salinity.In the process of ore formation,gold is transported in the form of Au(HS)2-complexes,with gold deposition being driven byfluid immiscibility.Therefore,the Yueguang gold deposit is categorized as an orogenic gold deposit dominated by metamorphic hydrother-malfluid.It may become a new target for gold exploration in the Baimashan region,central Hunan Province.
基金supported by the National Natural Science Foundation of China (Grant Nos.12205196 and 12275040)the National Key Research and Development Program of China (Grant No.2022YFE03090003)。
文摘Pellet injection is a primary method for fueling the plasma in magnetic confinement devices.For that goal the knowledges of pellet ablation and deposition profiles are critical.In the present study,the pellet fueling code HPI2 was used to predict the ablation and deposition profiles of deuterium pellets injected into a typical H-mode discharge on the EAST tokamak.Pellet ablation and deposition profiles were evaluated for various pellet injection locations,with the aim at optimizing the pellet injection to obtain a deep fueling depth.In this study,we investigate the effect of the injection angle on the deposition depth of the pellet at different velocities and sizes.The ablation and deposition of the injected pellet are mainly studied at each injection position for three different injection angles:0°,45°,and 60°.The pellet injection on the high field side(HFS)can achieve a more ideal deposition depth than on the low field side(LFS).Among these angles,horizontal injection on the middle plane is relatively better on either the HFS or the LFS.When the injection location is 0.468 m below the middle plane on the HFS or 0.40 m above the middle plane of the LFS,it can achieve a similar deposition depth to the one of its corresponding side.When the pre-cooling effect is taken into account,the deposition depth is predicted to increase only slightly when the pellet is launched from the HFS.The findings of this study will serve as a reference for the update of pellet injection systems for the EAST tokamak.
基金This work was supported by the National Natural Science Foundation of China(51874332,51991363)the CNPC's Major Science and Technology Projects(ZD2019-184-003)+1 种基金the Fundamental Research Funds for Central Universities(20CX05008A)“14th Five-Year plan”forward-looking basic major science and technology project of CNPC(2021DJ4901).
文摘Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low temperatures.Reducing hydrate adhesion on pipelines is viewed as an efficient way to prevent NGH blockages.Previous studies suggested the water film can greatly increase hydrate adhesion in gas-dominant system.Herein,by performing the molecular dynamics simulations,we find in water-dominant system,the water film plays different roles in hydrate deposition on Fe and its corrosion surfaces.Specifically,due to the strong affinity of water on Fe surface,the deposited hydrate cannot convert the adsorbed water into hydrate,thus,a water film exists.As water affinities decrease(Fe>Fe_(2)O_(3)>FeO>Fe_(3)O_(4)),adsorbed water would convert to amorphous hydrate on Fe_(2)O_(3)and form the ordered hydrate on FeO and Fe_(3)O_(4)after hydrate deposition.While absorbed water film converts to amorphous or to hydrate,the adhesion strength of hydrate continuously increases(Fe<Fe_(2)O_(3)<FeO<Fe_(3)O_(4)).This is because the detachment of deposited hydrate prefers to occur at soft region of liquid layer,the process of which becomes harder as liquid layer vanishes.As a result,contrary to gas-dominant system,the water film plays the weakening roles on hydrate adhesion in water-dominant system.Overall,our results can help to better understand the hydrate deposition mechanisms on Fe and its corrosion surfaces and suggest hydrate deposition can be adjusted by changing water affinities on pipeline surfaces.
基金supported by the National Natural Science Foundation of China(Grant No.41973045)Basic Science and Technology Research Funding of the CAGS(Grant No.JKYZD202312)+1 种基金the National Key Research and Development Project of China(Grant No.2022YFF0800903)National Natural Science Foundation of China(Grant Nos.41802113,42073053,42273073 and 42261144669).
文摘Lamprophyres typically appear in hydrothermal gold deposits.The relationship between lamprophyres and gold deposits is investigated widely.Some researchers suggest that the emplacement of lamprophyres triggers gold mineralization,whereas others hypothesize that the formation of lamprophyres increases the fertility of mantle sources and ore-forming fluids.K-feldspar veins,with ages between those of lamprophyres and gold deposits,appear in lamprophyres in Zhenyuan.Therefore,K-feldspar veins are ideal for investigating the relationship between lamprophyres and gold deposits.Phlogopite in K-feldspar veins has lower Mg#,Ni,and Cr contents and higher TiO2,Li,Ba,Sr,Sc,Zr,Nb,and Cs contents than phlogopite in lamprophyres.The in-situ Sr isotopic values of apatites(0.7063–0.7066)in K-feldspar veins are within the range for apatites(0.7064–0.7078)from lamprophyres.High large-ion lithophile element concentrations and low Nb and Ta concentrations in phlogopite from lamprophyres,in addition to high(87Sr/86Sr)i values of apatite(0.7064–0.7078),indicate that the magma parental to these phlogopite and apatite crystals is derived from an enriched mantle.Kfeldspar veins are genetically correlated with lamprophyres,whereas sulfide mineral assemblage and trace element compositions of pyrite in K-feldspar veins suggest that K-feldspar veins in lamprophyres are not directly related to gold mineralization of the Zhenyuan deposit.
基金funded by the China Postdoctoral Science Foundation(Grant No.2022M721614)the opening project of State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology(Grant No.KFJJ23-07M)。
文摘This paper proposes a type of double-layer charge liner fabricated using chemical vapor deposition(CVD)that has tungsten as its inner liner.The feasibility of this design was evaluated through penetration tests.Double-layer charge liners were fabricated by using CVD to deposit tungsten layers on the inner surfaces of pure T2 copper liners.The microstructures of the tungsten layers were analyzed using a scanning electron microscope(SEM).The feasibility analysis was carried out by pulsed X-rays,slug-retrieval test and static penetration tests.The shaped charge jet forming and penetration law of inner tungsten-coated double-layer liner were studied by numerical simulation method.The results showed that the double-layer liners could form well-shaped jets.The errors between the X-ray test results and the numerical results were within 11.07%.A slug-retrieval test was found that the retrieved slug was similar to a numerically simulated slug.Compared with the traditional pure copper shaped charge jet,the penetration depth of the double-layer shaped charge liner increased by 11.4% and>10.8% respectively.In summary,the test results are good,and the numerical simulation is in good agreement with the test,which verified the feasibility of using the CVD method to fabricate double-layer charge liners with a high-density and high-strength refractory metal as the inner liner.
文摘Tumor deposits(TDs)are defined as discrete,irregular clusters of tumor cells lying in the soft tissue adjacent to but separate from the primary tumor,and are usually found in the lymphatic drainage area of the primary tumor.By definition,no residual lymph node structure should be identified in these tumor masses.At present,TDs are mainly reported in colorectal cancer,with a few reports in gastric cancer.There are very few reports on breast cancer(BC).For TDs,current dominant theories suggest that these are the result of lymph node metastasis of the tumor with complete destruction of the lymph nodes by the tumor tissue.Even some pathologists classify a TD as two lymph node metastases for calculation.Some pathologists also believe that TDs belong to the category of disseminated metastasis.Therefore,regardless of the origin,TDs are an indicator of poor prognosis.Moreover,for BC,sentinel lymph node biopsy is generally used at present.Whether radical axillary lymph node dissection should be adopted for BC with TDs in axillary lymph nodes is still inconclusive.The present commentary of this clinical issue has certain guiding significance.It is aimed to increase the awareness of the scientific community towards this under-recognized problem in BC pathology.
基金Support for this study was received from Orient Resources Ltd.in Canada,Wuhan Institute of Technology,China,and College of Earth Sciences,Jilin University,China.
文摘By studying the light isotopic compositions of carbon,oxygen,and hydrogen,combined with previous research results on the ore-forming source of the deposit,the authors try to uncover its metallogenic origin.The δ^(18)O and δ^(13)C isotope signatures of dolomite samples vary between 10.2 and 13.0‰,and between−7.2 and−5.2‰,respectively,implying that the carbon derives from the upper mantle.δD and δ^(18) O of quartz,biotite,and muscovite from diff erent ore veins of the deposit vary between−82 and−59‰,and between 11.6 and 12.4‰,respectively,implying that the metallogenic solutions are mainly magmatic.According to the relevant research results of many isotope geologists,the fractionation degree of hydrogen isotopes increases as the depth to the Earth’s core increases,and the more diff erentiated the hydrogen isotopes are,the lower their values will be.In other words,mantle-derived solutions can have extremely low hydrogen isotope values.This means that the δD‰ value−134 of the pyrrhotite sample numbered SD-34 in this article may indicate mantle-derived oreforming fl uid of the deposit.The formation of the Dashuigou tellurium deposit occurred between 91.71 and 80.19 Ma.
基金supported by the National Key Research and Development Program of China(2022YFB3809005)by SINOPEC(120060-6,121027,and 122042).
文摘Aviation turbine engine oils require excellent thermal-oxidative stability because of their high-temperature environments.High-temperature bearing deposit testing is a mandatory method for measuring the thermal-oxidative performance of aviation lubricant oils,and the relevant apparatus was improved in the present study.Two different commercial aviation turbine engine oils were tested,one with standard performance(known as the SL oil)and the other with high thermal stability,and their thermal-oxidative stability characteristics were evaluated.After 100 h of high-temperature bearing testing,the SL oil was analyzed by using various analytical techniques to investigate its thermal-oxidative process in the bearing test,with its thermal-oxidative degradation mechanism also being discussed.The results indicate that the developed high-temperature bearing apparatus easily meets the test requirements of method 3410.1 in standard FED-STD-791D.The viscosity and total acid number(TAN)of the SL oil increased with the bearing test time,and various deposits were produced in the bearing test,with the micro-particles of the carbon deposits being sphere-like,rod-like,and sheet-like in appearance.The antioxidant additives in the oil were consumed very rapidly in the first 30 h of the bearing test,with N-phenyl-1-naphthylamine being consumed faster than dioctyldiphenylamine.Overall,the oil thermal-oxidative process involves very complex physical and chemical mechanisms.
基金funded by CNOOC Production Research Project(CCL2022SZPS0076).
文摘Asphaltene deposition is a significant problem during gas injection processes,as it can block the porous medium,the wellbore,and the involved facilities,significantly impacting reservoir productivity and ultimate oil recovery.Only a few studies have investigated the numerical modeling of this potential effect in porous media.This study focuses on asphaltene deposition due to natural gas and CO_(2) injection.Predictions of the effect of gas injection on asphaltene deposition behavior have been made using a 3D numerical simulation model.The results indicate that the injection of natural gas exacerbates asphaltene deposition,leading to a significant reduction in permeability near the injection well and throughout the reservoir.This reduction in permeability strongly affects the ability of gas toflow through the reservoir,resulting in an improvement of the displacement front.The displacement effi-ciency of the injection gas process increases by up to 1.40%when gas is injected at 5500 psi,compared to the scenario where the asphaltene model is not considered.CO_(2) injection leads to a miscible process with crude oil,extracting light and intermediate components,which intensifies asphaltene precipitation and increases the viscosity of the remaining crude oil,ultimately reducing the recovery rate.
基金funded by the “Laboratoire de Recherche Ressources, Matériaux et Ecosystémes”, University of Carthage 7021 Zarzouna, Bizerte, Tunisia
文摘The Ain El Bey abandoned mine, in North-West Tunisia, fits into the geodynamic context of the European and African plate boundary. Ore deposit corresponds to veins and breccia of multiphase Cu–Fe-rich mineralization related to various hydrothermal fluid circulations. Petromineralogical studies indicate a rich mineral paragenesis with a minimum of seven mineralization phases and, at least, six pyrite generations. As is also the case for galena and native silver, native gold is observed for the first time as inclusion in quartz which opens up, thus, new perspectives for prospecting and evaluating the potential for noble metals associated with the mineralization. Scanning Electron Microscope--Energy Dispersive Spectroscopy and Transmission electron microscopy analyses show, in addition, a large incorporation of trace elements, including Ag and Au, in mineral structures such as fahlores(tetrahedrite-tennantite) and chalcopyrite ones. The mineral/mineral associations, used as geothermometers, gave estimated temperatures for the mineralizing fluids varying from 254 to 330 ℃ for phase Ⅲ, from 254 to 350 ℃ for phase Ⅳ, and from 200 to 300 ℃ for phases Ⅴ and Ⅵ. The seventh and last identified mineralization phase, marked by a deposit of native gold, reflects a drop in the mineralizing fluid’s temperature(< 200 ℃) compatible with boiling conditions. Such results open up perspectives for the development of precious metal research and the revaluation of the Cu–Fe ore deposit at the Ain El Bey abandoned mine, as well as at the surrounding areas fitting in the geodynamic framework of the Africa-Europe plate boundary.
基金This work is supported by National Natural Science Founda-tion of China(U2004199)National Key Research and Devel-opment Program of China(2018YFD0200606)+1 种基金China Postdoctoral Science Foundation(2021T140615),Natural Sci-enceFoundationofHenanProvince(212300410285)Young Talent Support Project of Henan Province(2021HYTP028).
文摘Solid polymer electrolyte(SPE) shows great potential for all-solid-state batteries because of the inherent safety and flexibility;however, the unfavourable Li+deposition and large thickness hamper its development and application. Herein, a laminar MXene functional layer-thin SPE layer-cathode integration(MXene-PEO-LFP) is designed and fabricated. The MXene functional layer formed by stacking rigid MXene nanosheets imparts higher compressive strength relative to PEO electrolyte layer. And the abundant negatively-charged groups on MXene functional layer effectively repel anions and attract cations to adjust the charge distribution behavior at electrolyte–anode interface. Furthermore,the functional layer with rich lithiophilic groups and outstanding electronic conductivity results in low Li nucleation overpotential and nucleation energy barrier. In consequence, the cell assembled with MXene-PEO-LFP, where the PEO electrolyte layer is only 12 μm, much thinner than most solid electrolytes, exhibits uniform, dendrite-free Li+deposition and excellent cycling stability. High capacity(142.8 mAh g-1), stable operation of 140 cycles(capacity decay per cycle, 0.065%), and low polarization potential(0.5 C) are obtained in this Li|MXene-PEO-LFP cell,which is superior to most PEO-based electrolytes under identical condition. This integrated design may provide a strategy for the large-scale application of thin polymer electrolytes in all-solid-state battery.
文摘Dust deposition on the surface of photovoltaic (PV) cells poses a significant challenge to their efficiency, especially in arid regions characterized by desert and semi-desert conditions. Despite the pronounced impact of dust accumulation, these regions offer optimal solar radiation and minimal cloud cover, making them ideal candidates for widespread PV cell deployment. Various surface cleaning methods exist, each employing distinct approaches. Choosing an appropriate cleaning method requires a comprehensive understanding of the mechanisms involved in both dust deposition on module surfaces and dust adhesion to PV cell surfaces. The mechanisms governing dust deposition and adhesion are complex and multifaceted, influenced by factors such as the nature and properties of the dust particles, environmental climatic conditions, characteristics of protective coatings, and the specific location of the PV installation. These factors exhibit regional variations, necessitating the implementation of diverse cleaning approaches tailored to the unique conditions of each location. The first part of this article explores the factors influencing dust deposition on PV cell surfaces, delving into the intricate interplay of environmental variables and particle characteristics. Subsequently, the second part addresses various cleaning methods, offering an analysis of their respective advantages and disadvantages. By comprehensively examining the factors influencing dust accumulation and evaluating the effectiveness of different cleaning strategies, this article aims to contribute valuable insights to the ongoing efforts to optimize the performance and longevity of photovoltaic systems in diverse geographical contexts.
基金the China’s National Key Research and Development Program Projects(No.2022YFC3500500 and No.2022YFC3500502).
文摘Background: To explore the effects of electroacupuncture on cardiac function and myocardial fibrosis in rat models of heart failure, and to elucidate the underlying mechanism of electroacupuncture in heart failure treatment. Methods: Healthy male Sprague-Dawley rats were allocated into three groups: Sham group, Model group, and electroacupuncture (Model + EA) group, with each group comprising 8 rats. The model underwent a procedure involving the ligation of the left anterior descending coronary artery to induce a model of heart failure. The Model + EA group was used for 7 consecutive days for electroacupuncture of bilateral Shenmen (HT7) and Tongli (HT5), once a day for 30 min each time. Left ventricular parameters in rats were assessed using a small-animal ultrasound machine to analyze changes in left ventricular end-diastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction, and left ventricular fractional shortening. Serum interleukin-1β (IL-1β), cardiac troponin (cTn), and N-terminal brain natriuretic peptide precursor levels were measured using ELISA. Histopathological changes in rat myocardium were observed through HE staining, while collagen deposition in rat myocardial tissue was assessed using the Masson staining method. Picro sirius red staining, immunohistochemical staining, and RT-qPCR were utilized to distinguish between the various types of collagen deposition. The expression level of TGF-β1 and SMAD2/3/4/7 mRNA in rat myocardial tissues was determined using RT-qPCR. Additionally, western blot analysis was conducted to assess the protein expression levels of TGF-β1, SMAD3/7, and p-SMAD3 in rat myocardial tissues. Results: Compared with the Sham group, the left ventricular ejection fraction and left ventricular fractional shortening values of the Model group were significantly decreased (P < 0.01);the left ventricular end-diastolic volume and left ventricular end-systolic volume values were remarkably increased (P < 0.01);serum N-terminal brain natriuretic peptide precursor content was increased (P < 0.01);serum IL-1β and cTn levels were increased (P < 0.01);myocardial collagen volume fraction were increased (P < 0.01);and those of the expression of TGF-β1 and SMAD2/3/4 mRNA was increased (P < 0.01);the expression of SMAD7 mRNA was decreased (P < 0.01);the protein expression levels of TGF-β1, SMAD3, and p-Smad3 were increased (P < 0.01);the protein expression level of SMAD7 was decreased (P < 0.01) in the Model group. Compared to the Model group, the expression levels of the proteins TGF-β1, SMAD3, and p-Smad3 in myocardial tissue were found to be decreased (P < 0.01), and the expression level of the protein SMAD7 was found to be increased (P < 0.01) in the Model + EA group;the collagen volume fraction and deposition of type Ⅰ /Ⅲ collagen were decreased (P < 0.01) in the Model + EA group. Conclusion: Electroacupuncture alleviates myocardial fibrosis in rats with heart failure, and this effect is likely due to attributed to the modulation of the TGF-β1/Smads signaling pathway, which helps reduce collagen deposition in the extracellular matrix.
基金supported substantially by the Southwest Jiaotong University for Material and Financial Support。
文摘Graphene(Gr)has unique properties including high electrical conductivity;Thus,graphene/copper(Gr/Cu)composites have attracted increasing attention to replace traditional Cu for electrical applications. However,the problem of how to control graphene to form desired Gr/Cu composite is not well solved. This paper aims at exploring the best parameters for preparing graphene with different layers on Cu foil by chemical vapor deposition(CVD)method and studying the effects of different layers graphene on Gr/Cu composite’s electrical conductivity. Graphene grown on single-sided and double-sided copper was prepared for Gr/Cu and Gr/Cu/Gr composites. The resultant electrical conductivity of Gr/Cu composites increased with decreasing graphene layers and increasing graphene volume fraction. The Gr/Cu/Gr composite with monolayer graphene owns volume fraction of less than 0.002%,producing the best electrical conductivity up to59.8 ×10^(6)S/m,equivalent to 104.5% IACS and 105.3% pure Cu foil.
文摘In the light of field investigation, microscopic study, X\|ray phase analysis and mineral infrared spectral analysis, it is considered that laumontitization is of extensive occurrence in the Axi gold orefield. The development of laumontitization and its relationship to mineralization show that the laumontitization appeared mainly at the top of and in the periphery of orebodies, and occurred at the edge of the epithermal system or at the late stage of epithermal system evolution. Therefore, laumontitization can be used as an exploration indicator of epithermal gold deposits. The fluids responsible for laumontitization in the Axi gold orefield are similar to those producing hot spring\|type gold deposits or those from modern geothermal fields. Epithermal mineralization of the Axi gold deposit was dated at Carboniferous, indicating that the West Tianshan of China is a region favorable to epithermal\|type gold mineralization and preservation. Hence the West Tianshan of China is a target area for exploring epithermal gold deposits.
