Background Potassium(K)is an essential nutrient for plant growth and development.However,plant fertilization ignoring the soil K level is very likely to cause excessive fertilizer use,and further arouse a series of si...Background Potassium(K)is an essential nutrient for plant growth and development.However,plant fertilization ignoring the soil K level is very likely to cause excessive fertilizer use,and further arouse a series of side effects.This study investigated the response of cotton growth to different soil K levels and the uptake of major nutrients,aiming to evaluate the appropriate K supply level for cotton growth.Using a random block design with 6 soil K levels,we conducted 18 micro-zones field experiments over two continuous years.The soil available K concentration of each treatment was K1(99.77-100.90 mg·kg^(-1)),K2(110.90-111.26 mg·kg^(-1)),K3(123.48-128.88 mg·kg^(-1)),K4(140.13-145.10 mg·kg^(-1)),K5(154.43-155.38 mg·kg^(-1)),and K6(165.77-168.75 mg·kg^(-1)).Cotton nutrient contents,soil nutrient contents,accumulation and distribution of dry matter in cotton were determined,and the relationships between K content in soil and plants and dry matter accumulation were analyzed.Results The soil K content had a significantly positive relationship with dry matter and K accumulation in cotton plants.There were significant differences in dry matter accumulation,single-plant seed cotton yield,mineral nutrient uptake and the proportion of K accumulation in reproductive organs among different soil K levels.The results showed that there was significant difference between K4 and lower K level treatments(K1 and K2),but no significant difference between K4 and higher K level treatments(K5 and K6)in dry matter,single-plant seed cotton yield,or accumulation,distribution and seed cotton production efficiency of N,P and K.Conclusion The soil K level of K4 was able to provide sufficient K for cotton growth in our experiment.Therefore,when the soil K level reached 140.13 mg·kg^(-1),further increasing the soil K concentration no longer had a significant positive effect on cotton growth.展开更多
This study aims to shed light on the effects of financial development and accumula-tion of capital on the productivity of labor in the sub-Sahara African region within the period of 1990–2018.In this work,we used the...This study aims to shed light on the effects of financial development and accumula-tion of capital on the productivity of labor in the sub-Sahara African region within the period of 1990–2018.In this work,we used the(dynamic)common correlated effects estimator-mean group and additional techniques such as cross-section autoregressive distributed lag to calibrate the sample into the African subregion to ensure robustness.The findings reveal that financial progress in the region over time leads to an increase in productivity of labor and also the accumulation of capital.Furthermore,financial markets have a progressive impact on the productivity of labor within sub-Saharan African regions.We extend the very limited literature on the nexus between financial development and labor productivity by incorporating capital accumulation into our model which has not been previously studied.展开更多
The high water content of corn grain at harvest is a challenge in Northeast China,where the growing season is short.Using a dehydrating agent before harvest can help corn seeds dehydrate quickly.The dry matter accumul...The high water content of corn grain at harvest is a challenge in Northeast China,where the growing season is short.Using a dehydrating agent before harvest can help corn seeds dehydrate quickly.The dry matter accumulation and nutrient quality of maize were systematically studied by field experiments and instrumental analysis using maize varieties of different maturities as test materials.The results showed that the accumulation of dry matter was enhanced by an increased dosage of a dehydrating agent.When the dehydrating agent dosage reached 1800 mL•hm-2,the dry matter accumulation of early-maturing varieties increased by 24.1 g,and the water content decreased by 8.08%.Different maize varieties were treated with the same dose;early-maturing varieties showed significant effects on grain dry matter accumulation,and kernel dry matter accumulation increased by 7%.The effects of different doses on grain dehydration were obvious,and the effects on different maize varieties varied.Medium-ripening maize varieties showed the most significant effect,with a 19.5%reduction in water content.The effects of dehydrating agent doses on maize yield,grain nutrient quality and seed germination rate were not significant.Therefore,a dehydrating agent promoted the accumulation of dry matter in grain and accelerated the rapid dehydration.展开更多
As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to h...As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to heat stress during B.napus seed filling is helpful in the genetic improvement of heat-tolerant rapeseed.The effects of heat stress on seed oil accumulation and chlorophyll fluorescence characteristics of 29 B.napus germplasms with different oil content and environmental sensitivity,including 6 rapeseed varieties which exhibited environmentsensitive/insensitive and with high,medium or low oil content,were tested by whole plant heat stress or the in vitro silique culture system.Both assay exhibited similar trend on oil content of the rapeseed germplasms.The heat effect on the chlorophyll fluorescence kinetic parameters F_(v)/F_(m),ETR and Y(Ⅱ)were also consistent.Heat stress significantly decreased oil content,although there was abundant genetic variation on heat tolerance among the genotypes.Correlation analysis showed that the decrease rate of F_(v)/F_(m) of silique heat-stressed B.napus developing seed was positive correlative to the decrease rate of mature seed oil content of the whole plant heat-stressed rapeseed(R=0.9214,P-value<0.01).Overall,the results indicated that heat stress inhibited oil accumulation and photosynthesis in B.napus developing seed.The decrease rate of chlorophyll fluorescence parameter F_(v)/F_(m) of heat-stressed developing seed could be used as the index of heat tolerant rapeseed identification.Further,two heat insensitive rapeseed varieties with high oil content were identified.展开更多
Active ingredients from highland barley have received considerable attention as natural products for developing treatments and dietary supplements against obesity.In practical application,the research of food combinat...Active ingredients from highland barley have received considerable attention as natural products for developing treatments and dietary supplements against obesity.In practical application,the research of food combinations is more significant than a specific food component.This study investigated the lipid-lowering effect of highland barley polyphenols via lipase assay in vitro and HepG2 cells induced by oleic acid(OA).Five indexes,triglyceride(TG),total cholesterol(T-CHO),low density lipoprotein-cholesterol(LDL-C),aspartate aminotransferase(AST),and alanine aminotransferase(ALT),were used to evaluate the lipidlowering effect of highland barley extract.We also preliminary studied the lipid-lowering mechanism by Realtime fluorescent quantitative polymerase chain reaction(q PCR).The results indicated that highland barley extract contains many components with lipid-lowering effects,such as hyperoside and scoparone.In vitro,the lipase assay showed an 18.4%lipase inhibition rate when the additive contents of highland barley extract were 100μg/m L.The intracellular lipid-lowering effect of highland barley extract was examined using 0.25 mmol/L OA-induced HepG2 cells.The results showed that intracellular TG,LDL-C,and T-CHO content decreased by 34.4%,51.2%,and 18.4%,respectively.ALT and AST decreased by 51.6%and 20.7%compared with the untreated hyperlipidemic HepG2 cells.q PCR results showed that highland barley polyphenols could up-regulation the expression of lipid metabolism-related genes such as PPARγand Fabp4.展开更多
The high and steep slopes along a high-speed railway in the mountainous area of Southwest China are mostly composed of loose accumulations of debris with large internal pores and poor stability,which can easily induce...The high and steep slopes along a high-speed railway in the mountainous area of Southwest China are mostly composed of loose accumulations of debris with large internal pores and poor stability,which can easily induce adverse geological disasters under rainfall conditions.To ensure the smooth construction of the high-speed railway and the subsequent safe operation,it is necessary to master the stability evolution process of the loose accumulation slope under rainfall.This article simulates rainfall using the finite element analysis software’s hydromechanical coupling module.The slope stability under various rainfall situations is calculated and analysed based on the strength reduction method.To validate the simulation results,a field monitoring system is established to study the deformation characteristics of the slope under rainfall.The results show that rainfall duration is the key factor affecting slope stability.Given a constant amount of rainfall,the stability of the slope decreases with increasing duration of rainfall.Moreover,when the amount and duration of rainfall are constant,continuous rainfall has a greater impact on slope stability than intermittent rainfall.The setting of the field retaining structures has a significant role in improving slope stability.The field monitoring data show that the slope is in the initial deformation stage and has good stability,which verifies the rationality of the numerical simulation method.The research results can provide some references for understanding the influence of rainfall on the stability of loose accumulation slopes along high-speed railways and establishing a monitoring system.展开更多
With continuous hydrocarbon exploration extending to deeper basins,the deepest industrial oil accumulation was discovered below 8,200 m,revealing a new exploration field.Hence,the extent to which oil exploration can b...With continuous hydrocarbon exploration extending to deeper basins,the deepest industrial oil accumulation was discovered below 8,200 m,revealing a new exploration field.Hence,the extent to which oil exploration can be extended,and the prediction of the depth limit of oil accumulation(DLOA),are issues that have attracted significant attention in petroleum geology.Since it is difficult to characterize the evolution of the physical properties of the marine carbonate reservoir with burial depth,and the deepest drilling still cannot reach the DLOA.Hence,the DLOA cannot be predicted by directly establishing the relationship between the ratio of drilling to the dry layer and the depth.In this study,by establishing the relationships between the porosity and the depth and dry layer ratio of the carbonate reservoir,the relationships between the depth and dry layer ratio were obtained collectively.The depth corresponding to a dry layer ratio of 100%is the DLOA.Based on this,a quantitative prediction model for the DLOA was finally built.The results indicate that the porosity of the carbonate reservoir,Lower Ordovician in Tazhong area of Tarim Basin,tends to decrease with burial depth,and manifests as an overall low porosity reservoir in deep layer.The critical porosity of the DLOA was 1.8%,which is the critical geological condition corresponding to a 100%dry layer ratio encountered in the reservoir.The depth of the DLOA was 9,000 m.This study provides a new method for DLOA prediction that is beneficial for a deeper understanding of oil accumulation,and is of great importance for scientific guidance on deep oil drilling.展开更多
Extreme climate has increasingly led to negative impacts on forest ecosystems globally,especially in semiarid areas where forest ecosystems are more vulnerable.However,it is poorly understood how tree growth is affect...Extreme climate has increasingly led to negative impacts on forest ecosystems globally,especially in semiarid areas where forest ecosystems are more vulnerable.However,it is poorly understood how tree growth is affected by different drought events.In 2006–2009,the larch plantations in the semiarid areas of Northwest China were negatively affected by four consecutive dry years,which was a very rare phenomenon that may occur frequently under future climate warming.In this study,we analyzed the effect of these consecutive dry years on tree growth based on the data of the tree rings in the dominant layer of the forest canopy on a larch plantation.We found that the tree-ring width index(RWI)in dry years was lower than that in normal years,and it experienced a rapidly decreasing trend from 2006 to 2009(slope=-0.139 year^(-1),r=-0.94)due to water supply deficits in those dry years.Drought induced legacy effects of tree growth reduction,and consecutive dry years corresponded with greater growth reductions and legacy effects.Growth reductions and legacy effects were significantly stronger in the third and fourth consecutive dry years than that of single dry year(p<0.05),which might have been due to the cumulative stress caused by consecutive dry years.Our results showed that larch trees experienced greater tree growth reduction due to consecutive dry years and their legacy effect,and the trees had lower recovery rates after consecutive dry years.Our results highlight that consecutive dry years pose a new threat to plantations under climate warming,and thus,the effect of climate extremes on tree growth should be considered in growth models in semiarid areas.展开更多
240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge ef...240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge effects.Here,it is revealed that the peak optical output power increases by 81.83%with the size shrinking from 50.0 to 25.0μm.Thereinto,the LEE increases by 26.21%and the LEE enhancement mainly comes from the sidewall light extraction.Most notably,transversemagnetic(TM)mode light intensifies faster as the size shrinks due to the tilted mesa side-wall and Al reflector design.However,when it turns to 12.5μm sized micro-LEDs,the output power is lower than 25.0μm sized ones.The underlying mechanism is that even though protected by SiO2 passivation,the edge effect which leads to current leakage and Shockley-Read-Hall(SRH)recombination deteriorates rapidly with the size further shrinking.Moreover,the ratio of the p-contact area to mesa area is much lower,which deteriorates the p-type current spreading at the mesa edge.These findings show a role of thumb for the design of high efficiency micro-LEDs with wavelength below 250 nm,which will pave the way for wide applications of deep ultraviolet(DUV)micro-LEDs.展开更多
Light plays an important role in the photosynthesis and metabolic process of microalgae.However,how different light conditions regulate the biomass production and protein accumulation of microalgae is mostly unknown.I...Light plays an important role in the photosynthesis and metabolic process of microalgae.However,how different light conditions regulate the biomass production and protein accumulation of microalgae is mostly unknown.In this study,the influence of different light conditions,including light colors,densities,and light:dark cycles on the cell growth and biochemical composition of Spirulina platensis was symmetrically characterized.Under different colored lights,S.platensis all shows an increase trend within the increased light intensity ranges;however,each showing different optimal light intensities.At the same light intensity,different colored lights show different growth rate of S.platensis following the sequence of red>white>green>yellow>blue.The maximum growth rate and protein accumulation were determined as 21.88 and 5.10 mg/(L·d)when illuminated under red LED.The energy efficiency of different light sources was calculated and ranked as red>white>blue≈green>yellow.Transcriptomic analysis suggests that red light can promote cell growth and protein accumulation by upregulating genes related to photosynthesis,carbon fixation,and C-N metabolism pathways.This study provides a conducive and efficient way to promote biomass production and protein accumulation of S.platensis by regulating light conditions.展开更多
Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban...Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban forests and improvement of function.To clarify the effect of two forest types with different urbanization intensities,we determined differences in vegetation composition and diversity,structural traits,and carbon stocks of 152 plots(20 m×20 m)in urban park forests in Changchun,which had the largest green quantity and carbon density effectiveness.We found that 1.1-fold thicker and healthier trees,and 1.6-to 2.0-fold higher,healthier,denser,and more various shrubs but with sparser trees and herbs occurred in the central urban forests(p<0.05)than in the outer forests.The conifer forests exhibited 30–70%obviously higher tree aboveground carbon sequestration(including stem and leaf)and 20%bigger trees,especially in the outer forests(p<0.05).In contrast,1.1-to 1.5-fold higher branch stocks,healthier and more diverse trees were found in broadleaved forests of both the inner and outer forests(p<0.05).Plant size and dominant species had similarly important roles in carbon stock improvement,especially big-sized woody plants and Pinus tabuliformis.In addition,a higher number of deciduous or needle species positively affected the broadleaved forest of the central urban area and conifer forest of the outer urban area,respectively.These findings can be used to guide precise management and accelerate the improvement of urban carbon function in Northeast China in the future.展开更多
This paper realizes the full-domain collaborative deployment of multiple interference sources of the global satellite navigation system(GNSS)and evaluates the deployment effect to enhance the ability to disturb the at...This paper realizes the full-domain collaborative deployment of multiple interference sources of the global satellite navigation system(GNSS)and evaluates the deployment effect to enhance the ability to disturb the attacker and the capability to defend the GNSS during navigation countermeasures.Key evaluation indicators for the jamming effect of GNSS suppressive and deceptive jamming sources are first created,their evaluation models are built,and their detection procedures are sorted out,as the basis for determining the deployment principles.The principles for collaboratively deploying multi-jamming sources are developed to obtain the deployment structures(including the required number,structures in demand,and corresponding positions)of three single interference sources required by collaboratively deploying.Accordingly,simulation and hardware-in-loop testing results are presented to determine a rational configuration of the collaborative deployment of multi-jamming sources in the set situation and further realize the full-domain deployment of an interference network from ground,air to space.Varied evaluation indices for the deployment effect are finally developed to evaluate the deployment effect of the proposed configuration and further verify its reliability and rationality.展开更多
Sickle cell disease (SCD) is a prevalent condition, particularly in the countries of sub-Saharan Africa, where the presence of specific genes associated with Malaria contributes to its high prevalence. Patients with s...Sickle cell disease (SCD) is a prevalent condition, particularly in the countries of sub-Saharan Africa, where the presence of specific genes associated with Malaria contributes to its high prevalence. Patients with sickle cell disease frequently experience painful episodes necessitating hospitalization, and their hemoglobin levels are typically lower than those of the general population. There are different treatment options available to manage complications, such as transfusing blood, hydroxyurea, and strong anti-pains. However, with all these treatments, patients still commonly experience pain crises and suffer from organ damage. Hydroxyurea, the sole approved medication for sickle cell anemia in developed and developing countries, is widely used in children despite being primarily indicated for adults. Multiple studies have demonstrated the efficacy of hydroxyurea in inducing HbF production in young children with SCD. Elevated HbF levels have been associated with improved clinical outcomes, including a reduction in vaso-occlusive crises, acute chest syndrome, and the need for blood transfusions. Furthermore, increased HbF levels have been shown to ameliorate disease-related organ damage, such as pulmonary hypertension and sickle cell retinopathy. The response to hydroxyurea treatment in young children with SCD is variable. Some patients achieve substantial increases in HbF levels and experience significant clinical benefits, while others may have a more modest response. Factors influencing the response include baseline HbF levels, genetic modifiers, treatment adherence, and dose optimization. Safety is a crucial consideration when using hydroxyurea in young children. Studies have shown that hydroxyurea is generally well-tolerated, with the most common adverse effects being myelosuppression, gastrointestinal symptoms, and dermatological manifestations. However,long-term effects and potential risks, such as renal dysfunction and reproductive impacts, require further investigation. The effectiveness of hydroxyurea in young children with SCD has been demonstrated in various clinical trials and observational studies. These studies have shown a significant reduction in disease-related complications and improved quality of life. However, optimal dosing, treatment duration, and long-term outcomes are still areas of ongoing research. This review focuses on recent studies investigating the benefits, effectiveness, responses, and safety of hydroxyurea in pediatric individuals diagnosed with sickle cell disease.展开更多
Monitoring of heavy metals contamination of agricultural products and their transfer and bioaccumulation in crops like rice has become a hot topic worldwide over the last two decades. The present study was carried out...Monitoring of heavy metals contamination of agricultural products and their transfer and bioaccumulation in crops like rice has become a hot topic worldwide over the last two decades. The present study was carried out to determine the accumulation of heavy metals in rice fields and their transfer to rice grains. Soil, irrigation water and rice grains samples were gathered in Maga-Pouss, Far-North, Cameroon. Concentrations of six heavy metals (lead, cadmium, zinc, copper, iron and mercury) were evaluated by Atomic Absorption Spectrophotometer (AAS). Mercury was not detected in this study. Average concentrations of metals were in this order (in mg/kg): Fe (188.60 ± 97.06) > Pb (63.63 ± 7.11) > Cd (2.59 ± 0.29) > Zn (1.10 ± 1.05) > Cu (0.80 ± 0.73) in water and Pb (105.50 ± 31.11) > Fe (105.50 ± 31.11) > Cu (45.93 ± 14.39) > Zn (22.52 ± 6.40) > Cd (3.15 ± 0.49) in soil. Water in Maga-Pouss rice fields appears to be more harmful than the soil, notably for lead, cadmium and copper. In rice grains, heavy metals were found in this order (mg/kg): Fe (188.01 ± 82.62) > Cu (27.20 ± 0.00) > Zn (23.61 ± 12.42) > Pb (19.50 ± 19.91) > Cd (2.02 ± 1.05). The mean bioconcentration factor (BCF) of metals from soil to rice grains was in the following order: Fe (2.60) > Zn (1.05) > Cd (0.64) > Cu (0.59) > Pb (0.18). From water to rice grains, the order is: Cu (37.26) > Zn (22.49) > Cd (6.97) > Pb (2.74) > Fe (1.94). Rice field pH and electrical conductivity favored the uptake of lead, copper and cadmium by rice grains. The findings of this study will be good documentation for risk assessment, and decision-making by environmental managers in this region.展开更多
Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The r...Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The results indicated that AMF significantly increased rice biomass,with an increase of up to 40.0%,particularly in root biomass by up to 68.4%.Notably,the number of prominent rice individuals also increased,and their plasticity was enhanced following AMF inoculation.AMF led to an increase in the net photosynthetic rate and antioxidant enzyme activity of rice.In the AMF treatment group,the Cd concentration in the rice roots was significantly higher(19.1%‒68.0%)compared with that in the control group.Conversely,the Cd concentration in the rice seeds was lower in the AMF treatment group,indicating that AMF facilitated the sequestration of Cd in rice roots and reduced Cd accumulation in the seeds.Path coefficients varied across different treatments,suggesting that AMF inoculation reduced the direct impact of soil Cd concentration on the total Cd accumulation in seeds.The translocation of Cd was consistently associated with simultaneous growth dilution and compensatory accumulation as a result of mycorrhizal effects.Our study quantitatively analyzed this process through path analysis and clarified the causal relationship between rice growth and Cd transfer under the influence of AMF.展开更多
Hybrid skin-topological effect(HSTE)in non-Hermitian systems exhibits both the skin effect and topological protection,offering a novel mechanism for localization of topological edge states(TESs)in electrons,circuits,a...Hybrid skin-topological effect(HSTE)in non-Hermitian systems exhibits both the skin effect and topological protection,offering a novel mechanism for localization of topological edge states(TESs)in electrons,circuits,and photons.However,it remains unclear whether the HSTE can be realized in quasicrystals.展开更多
The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source rocks.However,the mechanism of organic m...The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source rocks.However,the mechanism of organic matter(OM)enrichment throughout this period is still controversial.Based on geochemical data,the marine redox conditions,paleogeographic and hydrographic environment,primary productivity,volcanism,and terrigenous input during the Late Permian in the Lower Yangtze region have been studied from the Putaoling section,Chaohu,to provide new insights into OM accumulation.Five Phases are distinguished based on the TOC and environmental variations.In Phase I,anoxic conditions driven by water restriction enhanced OM preservation.In Phase II,euxinic and cycling hydrological environments were the two most substantial controlling factors for the massive OM deposition.During Phase III,intensified terrestrial input potentially diluted the OM in sediment and the presence of oxygen in bottom water weakened the preservation condition.Phase IV was characterized by a relatively higher abundance of mercury(Hg)and TOC(peak at 16.98 wt%),indicating that enhanced volcanism potentially stimulated higher productivity and a euxinic environment.In Phase V,extremely lean OM was preserved as a result of terrestrial dilutions and decreasing primary productivity.Phases I,II and IV are characterized as the most prominent OM-rich zones due to the effective interactions of the controlling factors,namely paleogeographic,hydrographic environment,volcanism,and redox conditions.展开更多
The Ediacaran–Ordovician strata within three major marine basins(Tarim,Sichuan,and Ordos)in China are analyzed.Based on previous studies focusing on the characteristics of the Neoproterozoic–Cambrian strata within t...The Ediacaran–Ordovician strata within three major marine basins(Tarim,Sichuan,and Ordos)in China are analyzed.Based on previous studies focusing on the characteristics of the Neoproterozoic–Cambrian strata within the three major basins(East Siberian,Oman,and Officer in Australia)overseas,the carbonate–evaporite assemblages in the target interval are divided into three types:intercalated carbonate and gypsum salt,interbedded carbonate and gypsum salt,and coexisted carbonate,gypsum salt and clastic rock.Moreover,the concept and definition of the carbonate-evaporite assemblage are clarified.The results indicate that the oil and gas in the carbonate-evaporite assemblage are originated from two types of source rocks:shale and argillaceous carbonate,and confirmed the capability of gypsum salt in the saline environment to drive the source rock hydrocarbon generation.The dolomite reservoirs are classified in two types:gypseous dolomite flat,and grain shoalµbial mound.This study clarifies that the penecontemporaneous or epigenic leaching of atmospheric fresh water mainly controlled the large-scale development of reservoirs.Afterwards,burial dissolution transformed and reworked the reservoirs.The hydrocarbon accumulation in carbonate-evaporite assemblage can be categorized into eight sub-models under three models(sub-evaporite hydrocarbon accumulation,supra-evaporite hydrocarbon accumulation,and inter-evaporite hydrocarbon accumulation).As a result,the Cambrian strata in the Tazhong Uplift North Slope,Maigaiti Slope and Mazatag Front Uplift Zone of the Tarim Basin,the Cambrian strata in the eastern-southern area of the Sichuan Basin,and the inter-evaporite Ma-4 Member of Ordovician in the Ordos Basin,China,are defined as favorable targets for future exploration.展开更多
To investigate the mechanism of rockburst prevention by spraying water onto the surrounding rocks,15 experiments are performed considering different water absorption levels on a single face.High-speed photography and ...To investigate the mechanism of rockburst prevention by spraying water onto the surrounding rocks,15 experiments are performed considering different water absorption levels on a single face.High-speed photography and acoustic emission(AE)system are used to monitor the rockburst process.The effect of water on sandstone rockburst and the prevention mechanism of water on sandstone rockburst are analyzed from the perspective of energy and failure mode.The results show that the higher the ab-sorption degree,the lower the intensity of the rockburst after absorbing water on single side of sand-stone.This is reflected in the fact that with the increase in the water absorption level,the ejection velocity of rockburst fragments is smaller,the depth of the rockburst pit is shallower,and the AE energy is smaller.Under the water absorption level of 100%,the magnitude of rockburst intensity changes from medium to slight.The prevention mechanism of water on sandstone rockburst is that water reduces the capacity of sandstone to store strain energy and accelerates the expansion of shear cracks,which is not conducive to the occurrence of plate cracking before rockburst,and destroys the conditions for rockburst incubation.展开更多
This study investigates the properties of exciton-polaritons in a two-dimensional(2D)hybrid organic-inorganic perovskite microcavity in the presence of optical Stark effect.Through both steady and dynamic state analys...This study investigates the properties of exciton-polaritons in a two-dimensional(2D)hybrid organic-inorganic perovskite microcavity in the presence of optical Stark effect.Through both steady and dynamic state analyses,strong coupling between excitons of perovskite and cavity photons is revealed,indicating the formation of polaritons in the perovskite microcavity.Besides,it is found that an external optical Stark pulse can induce energy shifts of excitons proportional to the pulse intensity,which modifies the dispersion characteristics of the polaritons.展开更多
基金supported by Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciencesthe earmarked fund of China Agricultural Research System of China(CARS-15-11).
文摘Background Potassium(K)is an essential nutrient for plant growth and development.However,plant fertilization ignoring the soil K level is very likely to cause excessive fertilizer use,and further arouse a series of side effects.This study investigated the response of cotton growth to different soil K levels and the uptake of major nutrients,aiming to evaluate the appropriate K supply level for cotton growth.Using a random block design with 6 soil K levels,we conducted 18 micro-zones field experiments over two continuous years.The soil available K concentration of each treatment was K1(99.77-100.90 mg·kg^(-1)),K2(110.90-111.26 mg·kg^(-1)),K3(123.48-128.88 mg·kg^(-1)),K4(140.13-145.10 mg·kg^(-1)),K5(154.43-155.38 mg·kg^(-1)),and K6(165.77-168.75 mg·kg^(-1)).Cotton nutrient contents,soil nutrient contents,accumulation and distribution of dry matter in cotton were determined,and the relationships between K content in soil and plants and dry matter accumulation were analyzed.Results The soil K content had a significantly positive relationship with dry matter and K accumulation in cotton plants.There were significant differences in dry matter accumulation,single-plant seed cotton yield,mineral nutrient uptake and the proportion of K accumulation in reproductive organs among different soil K levels.The results showed that there was significant difference between K4 and lower K level treatments(K1 and K2),but no significant difference between K4 and higher K level treatments(K5 and K6)in dry matter,single-plant seed cotton yield,or accumulation,distribution and seed cotton production efficiency of N,P and K.Conclusion The soil K level of K4 was able to provide sufficient K for cotton growth in our experiment.Therefore,when the soil K level reached 140.13 mg·kg^(-1),further increasing the soil K concentration no longer had a significant positive effect on cotton growth.
文摘This study aims to shed light on the effects of financial development and accumula-tion of capital on the productivity of labor in the sub-Sahara African region within the period of 1990–2018.In this work,we used the(dynamic)common correlated effects estimator-mean group and additional techniques such as cross-section autoregressive distributed lag to calibrate the sample into the African subregion to ensure robustness.The findings reveal that financial progress in the region over time leads to an increase in productivity of labor and also the accumulation of capital.Furthermore,financial markets have a progressive impact on the productivity of labor within sub-Saharan African regions.We extend the very limited literature on the nexus between financial development and labor productivity by incorporating capital accumulation into our model which has not been previously studied.
基金Supported by the Research and Development Plan of Applied Technology in Heilongjiang Province(GA19B104)。
文摘The high water content of corn grain at harvest is a challenge in Northeast China,where the growing season is short.Using a dehydrating agent before harvest can help corn seeds dehydrate quickly.The dry matter accumulation and nutrient quality of maize were systematically studied by field experiments and instrumental analysis using maize varieties of different maturities as test materials.The results showed that the accumulation of dry matter was enhanced by an increased dosage of a dehydrating agent.When the dehydrating agent dosage reached 1800 mL•hm-2,the dry matter accumulation of early-maturing varieties increased by 24.1 g,and the water content decreased by 8.08%.Different maize varieties were treated with the same dose;early-maturing varieties showed significant effects on grain dry matter accumulation,and kernel dry matter accumulation increased by 7%.The effects of different doses on grain dehydration were obvious,and the effects on different maize varieties varied.Medium-ripening maize varieties showed the most significant effect,with a 19.5%reduction in water content.The effects of dehydrating agent doses on maize yield,grain nutrient quality and seed germination rate were not significant.Therefore,a dehydrating agent promoted the accumulation of dry matter in grain and accelerated the rapid dehydration.
基金funded by the Natural Science Foundation of Zhejiang Province(LY20C130006)the National Natural Science Foundation of China(32172018)the State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products(2010DS700124-ZZ1805).
文摘As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to heat stress during B.napus seed filling is helpful in the genetic improvement of heat-tolerant rapeseed.The effects of heat stress on seed oil accumulation and chlorophyll fluorescence characteristics of 29 B.napus germplasms with different oil content and environmental sensitivity,including 6 rapeseed varieties which exhibited environmentsensitive/insensitive and with high,medium or low oil content,were tested by whole plant heat stress or the in vitro silique culture system.Both assay exhibited similar trend on oil content of the rapeseed germplasms.The heat effect on the chlorophyll fluorescence kinetic parameters F_(v)/F_(m),ETR and Y(Ⅱ)were also consistent.Heat stress significantly decreased oil content,although there was abundant genetic variation on heat tolerance among the genotypes.Correlation analysis showed that the decrease rate of F_(v)/F_(m) of silique heat-stressed B.napus developing seed was positive correlative to the decrease rate of mature seed oil content of the whole plant heat-stressed rapeseed(R=0.9214,P-value<0.01).Overall,the results indicated that heat stress inhibited oil accumulation and photosynthesis in B.napus developing seed.The decrease rate of chlorophyll fluorescence parameter F_(v)/F_(m) of heat-stressed developing seed could be used as the index of heat tolerant rapeseed identification.Further,two heat insensitive rapeseed varieties with high oil content were identified.
基金financially supported by the National Key Research and Development Program of China(2021YFD2100904)the National Natural Science Foundation of China(31871729,32172147)+2 种基金the Modern Agriculture key Project of Jiangsu Province of China(BE2022317)the Modern Agricultural Industrial Technology System Construction Project of Jiangsu Province of China(JATS[2021]522)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Active ingredients from highland barley have received considerable attention as natural products for developing treatments and dietary supplements against obesity.In practical application,the research of food combinations is more significant than a specific food component.This study investigated the lipid-lowering effect of highland barley polyphenols via lipase assay in vitro and HepG2 cells induced by oleic acid(OA).Five indexes,triglyceride(TG),total cholesterol(T-CHO),low density lipoprotein-cholesterol(LDL-C),aspartate aminotransferase(AST),and alanine aminotransferase(ALT),were used to evaluate the lipidlowering effect of highland barley extract.We also preliminary studied the lipid-lowering mechanism by Realtime fluorescent quantitative polymerase chain reaction(q PCR).The results indicated that highland barley extract contains many components with lipid-lowering effects,such as hyperoside and scoparone.In vitro,the lipase assay showed an 18.4%lipase inhibition rate when the additive contents of highland barley extract were 100μg/m L.The intracellular lipid-lowering effect of highland barley extract was examined using 0.25 mmol/L OA-induced HepG2 cells.The results showed that intracellular TG,LDL-C,and T-CHO content decreased by 34.4%,51.2%,and 18.4%,respectively.ALT and AST decreased by 51.6%and 20.7%compared with the untreated hyperlipidemic HepG2 cells.q PCR results showed that highland barley polyphenols could up-regulation the expression of lipid metabolism-related genes such as PPARγand Fabp4.
基金supported by the National Natural Science Foundation of China (No.51978588).
文摘The high and steep slopes along a high-speed railway in the mountainous area of Southwest China are mostly composed of loose accumulations of debris with large internal pores and poor stability,which can easily induce adverse geological disasters under rainfall conditions.To ensure the smooth construction of the high-speed railway and the subsequent safe operation,it is necessary to master the stability evolution process of the loose accumulation slope under rainfall.This article simulates rainfall using the finite element analysis software’s hydromechanical coupling module.The slope stability under various rainfall situations is calculated and analysed based on the strength reduction method.To validate the simulation results,a field monitoring system is established to study the deformation characteristics of the slope under rainfall.The results show that rainfall duration is the key factor affecting slope stability.Given a constant amount of rainfall,the stability of the slope decreases with increasing duration of rainfall.Moreover,when the amount and duration of rainfall are constant,continuous rainfall has a greater impact on slope stability than intermittent rainfall.The setting of the field retaining structures has a significant role in improving slope stability.The field monitoring data show that the slope is in the initial deformation stage and has good stability,which verifies the rationality of the numerical simulation method.The research results can provide some references for understanding the influence of rainfall on the stability of loose accumulation slopes along high-speed railways and establishing a monitoring system.
基金This work was supported by the Beijing Nova Program[Z211100002121136]Open Fund Project of State Key Laboratory of Lithospheric Evolution[SKL-K202103]+1 种基金Joint Funds of National Natural Science Foundation of China[U19B6003-02]the National Natural Science Foundation of China[42302149].We would like to thank Prof.Zhu Rixiang from the Institute of Geology and Geophysics,Chinese Academy of Sciences.
文摘With continuous hydrocarbon exploration extending to deeper basins,the deepest industrial oil accumulation was discovered below 8,200 m,revealing a new exploration field.Hence,the extent to which oil exploration can be extended,and the prediction of the depth limit of oil accumulation(DLOA),are issues that have attracted significant attention in petroleum geology.Since it is difficult to characterize the evolution of the physical properties of the marine carbonate reservoir with burial depth,and the deepest drilling still cannot reach the DLOA.Hence,the DLOA cannot be predicted by directly establishing the relationship between the ratio of drilling to the dry layer and the depth.In this study,by establishing the relationships between the porosity and the depth and dry layer ratio of the carbonate reservoir,the relationships between the depth and dry layer ratio were obtained collectively.The depth corresponding to a dry layer ratio of 100%is the DLOA.Based on this,a quantitative prediction model for the DLOA was finally built.The results indicate that the porosity of the carbonate reservoir,Lower Ordovician in Tazhong area of Tarim Basin,tends to decrease with burial depth,and manifests as an overall low porosity reservoir in deep layer.The critical porosity of the DLOA was 1.8%,which is the critical geological condition corresponding to a 100%dry layer ratio encountered in the reservoir.The depth of the DLOA was 9,000 m.This study provides a new method for DLOA prediction that is beneficial for a deeper understanding of oil accumulation,and is of great importance for scientific guidance on deep oil drilling.
基金the National Natural Science Foundation of China(Nos.42161144008U21A2005+3 种基金U20A2085)the National Key Research and Development Program of China(2022YFF08018042022YFF08018032022YFF1300404)。
文摘Extreme climate has increasingly led to negative impacts on forest ecosystems globally,especially in semiarid areas where forest ecosystems are more vulnerable.However,it is poorly understood how tree growth is affected by different drought events.In 2006–2009,the larch plantations in the semiarid areas of Northwest China were negatively affected by four consecutive dry years,which was a very rare phenomenon that may occur frequently under future climate warming.In this study,we analyzed the effect of these consecutive dry years on tree growth based on the data of the tree rings in the dominant layer of the forest canopy on a larch plantation.We found that the tree-ring width index(RWI)in dry years was lower than that in normal years,and it experienced a rapidly decreasing trend from 2006 to 2009(slope=-0.139 year^(-1),r=-0.94)due to water supply deficits in those dry years.Drought induced legacy effects of tree growth reduction,and consecutive dry years corresponded with greater growth reductions and legacy effects.Growth reductions and legacy effects were significantly stronger in the third and fourth consecutive dry years than that of single dry year(p<0.05),which might have been due to the cumulative stress caused by consecutive dry years.Our results showed that larch trees experienced greater tree growth reduction due to consecutive dry years and their legacy effect,and the trees had lower recovery rates after consecutive dry years.Our results highlight that consecutive dry years pose a new threat to plantations under climate warming,and thus,the effect of climate extremes on tree growth should be considered in growth models in semiarid areas.
基金This work was supported by National Key R&D Program of China(2022YFB3605103)the National Natural Science Foundation of China(62204241,U22A2084,62121005,and 61827813)+3 种基金the Natural Science Foundation of Jilin Province(20230101345JC,20230101360JC,and 20230101107JC)the Youth Innovation Promotion Association of CAS(2023223)the Young Elite Scientist Sponsorship Program By CAST(YESS20200182)the CAS Talents Program(E30122E4M0).
文摘240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge effects.Here,it is revealed that the peak optical output power increases by 81.83%with the size shrinking from 50.0 to 25.0μm.Thereinto,the LEE increases by 26.21%and the LEE enhancement mainly comes from the sidewall light extraction.Most notably,transversemagnetic(TM)mode light intensifies faster as the size shrinks due to the tilted mesa side-wall and Al reflector design.However,when it turns to 12.5μm sized micro-LEDs,the output power is lower than 25.0μm sized ones.The underlying mechanism is that even though protected by SiO2 passivation,the edge effect which leads to current leakage and Shockley-Read-Hall(SRH)recombination deteriorates rapidly with the size further shrinking.Moreover,the ratio of the p-contact area to mesa area is much lower,which deteriorates the p-type current spreading at the mesa edge.These findings show a role of thumb for the design of high efficiency micro-LEDs with wavelength below 250 nm,which will pave the way for wide applications of deep ultraviolet(DUV)micro-LEDs.
基金the National Natural Science Foundation of China(Nos.42061134020,32070380)the Natural Science Foundation of Shandong Province(No.ZR2019ZD17)。
文摘Light plays an important role in the photosynthesis and metabolic process of microalgae.However,how different light conditions regulate the biomass production and protein accumulation of microalgae is mostly unknown.In this study,the influence of different light conditions,including light colors,densities,and light:dark cycles on the cell growth and biochemical composition of Spirulina platensis was symmetrically characterized.Under different colored lights,S.platensis all shows an increase trend within the increased light intensity ranges;however,each showing different optimal light intensities.At the same light intensity,different colored lights show different growth rate of S.platensis following the sequence of red>white>green>yellow>blue.The maximum growth rate and protein accumulation were determined as 21.88 and 5.10 mg/(L·d)when illuminated under red LED.The energy efficiency of different light sources was calculated and ranked as red>white>blue≈green>yellow.Transcriptomic analysis suggests that red light can promote cell growth and protein accumulation by upregulating genes related to photosynthesis,carbon fixation,and C-N metabolism pathways.This study provides a conducive and efficient way to promote biomass production and protein accumulation of S.platensis by regulating light conditions.
基金the Youth Growth Technology Project,Science and Technology Department of Jilin Province(20230508130RC)Bureau of Forestry and Landscaping of Changchun.
文摘Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban forests and improvement of function.To clarify the effect of two forest types with different urbanization intensities,we determined differences in vegetation composition and diversity,structural traits,and carbon stocks of 152 plots(20 m×20 m)in urban park forests in Changchun,which had the largest green quantity and carbon density effectiveness.We found that 1.1-fold thicker and healthier trees,and 1.6-to 2.0-fold higher,healthier,denser,and more various shrubs but with sparser trees and herbs occurred in the central urban forests(p<0.05)than in the outer forests.The conifer forests exhibited 30–70%obviously higher tree aboveground carbon sequestration(including stem and leaf)and 20%bigger trees,especially in the outer forests(p<0.05).In contrast,1.1-to 1.5-fold higher branch stocks,healthier and more diverse trees were found in broadleaved forests of both the inner and outer forests(p<0.05).Plant size and dominant species had similarly important roles in carbon stock improvement,especially big-sized woody plants and Pinus tabuliformis.In addition,a higher number of deciduous or needle species positively affected the broadleaved forest of the central urban area and conifer forest of the outer urban area,respectively.These findings can be used to guide precise management and accelerate the improvement of urban carbon function in Northeast China in the future.
基金the National Natural Science Foundation of China(Grant No.42174047 and No.42174036)the National Science Foundation Project for Outstanding Youth(No.42104034).
文摘This paper realizes the full-domain collaborative deployment of multiple interference sources of the global satellite navigation system(GNSS)and evaluates the deployment effect to enhance the ability to disturb the attacker and the capability to defend the GNSS during navigation countermeasures.Key evaluation indicators for the jamming effect of GNSS suppressive and deceptive jamming sources are first created,their evaluation models are built,and their detection procedures are sorted out,as the basis for determining the deployment principles.The principles for collaboratively deploying multi-jamming sources are developed to obtain the deployment structures(including the required number,structures in demand,and corresponding positions)of three single interference sources required by collaboratively deploying.Accordingly,simulation and hardware-in-loop testing results are presented to determine a rational configuration of the collaborative deployment of multi-jamming sources in the set situation and further realize the full-domain deployment of an interference network from ground,air to space.Varied evaluation indices for the deployment effect are finally developed to evaluate the deployment effect of the proposed configuration and further verify its reliability and rationality.
文摘Sickle cell disease (SCD) is a prevalent condition, particularly in the countries of sub-Saharan Africa, where the presence of specific genes associated with Malaria contributes to its high prevalence. Patients with sickle cell disease frequently experience painful episodes necessitating hospitalization, and their hemoglobin levels are typically lower than those of the general population. There are different treatment options available to manage complications, such as transfusing blood, hydroxyurea, and strong anti-pains. However, with all these treatments, patients still commonly experience pain crises and suffer from organ damage. Hydroxyurea, the sole approved medication for sickle cell anemia in developed and developing countries, is widely used in children despite being primarily indicated for adults. Multiple studies have demonstrated the efficacy of hydroxyurea in inducing HbF production in young children with SCD. Elevated HbF levels have been associated with improved clinical outcomes, including a reduction in vaso-occlusive crises, acute chest syndrome, and the need for blood transfusions. Furthermore, increased HbF levels have been shown to ameliorate disease-related organ damage, such as pulmonary hypertension and sickle cell retinopathy. The response to hydroxyurea treatment in young children with SCD is variable. Some patients achieve substantial increases in HbF levels and experience significant clinical benefits, while others may have a more modest response. Factors influencing the response include baseline HbF levels, genetic modifiers, treatment adherence, and dose optimization. Safety is a crucial consideration when using hydroxyurea in young children. Studies have shown that hydroxyurea is generally well-tolerated, with the most common adverse effects being myelosuppression, gastrointestinal symptoms, and dermatological manifestations. However,long-term effects and potential risks, such as renal dysfunction and reproductive impacts, require further investigation. The effectiveness of hydroxyurea in young children with SCD has been demonstrated in various clinical trials and observational studies. These studies have shown a significant reduction in disease-related complications and improved quality of life. However, optimal dosing, treatment duration, and long-term outcomes are still areas of ongoing research. This review focuses on recent studies investigating the benefits, effectiveness, responses, and safety of hydroxyurea in pediatric individuals diagnosed with sickle cell disease.
文摘Monitoring of heavy metals contamination of agricultural products and their transfer and bioaccumulation in crops like rice has become a hot topic worldwide over the last two decades. The present study was carried out to determine the accumulation of heavy metals in rice fields and their transfer to rice grains. Soil, irrigation water and rice grains samples were gathered in Maga-Pouss, Far-North, Cameroon. Concentrations of six heavy metals (lead, cadmium, zinc, copper, iron and mercury) were evaluated by Atomic Absorption Spectrophotometer (AAS). Mercury was not detected in this study. Average concentrations of metals were in this order (in mg/kg): Fe (188.60 ± 97.06) > Pb (63.63 ± 7.11) > Cd (2.59 ± 0.29) > Zn (1.10 ± 1.05) > Cu (0.80 ± 0.73) in water and Pb (105.50 ± 31.11) > Fe (105.50 ± 31.11) > Cu (45.93 ± 14.39) > Zn (22.52 ± 6.40) > Cd (3.15 ± 0.49) in soil. Water in Maga-Pouss rice fields appears to be more harmful than the soil, notably for lead, cadmium and copper. In rice grains, heavy metals were found in this order (mg/kg): Fe (188.01 ± 82.62) > Cu (27.20 ± 0.00) > Zn (23.61 ± 12.42) > Pb (19.50 ± 19.91) > Cd (2.02 ± 1.05). The mean bioconcentration factor (BCF) of metals from soil to rice grains was in the following order: Fe (2.60) > Zn (1.05) > Cd (0.64) > Cu (0.59) > Pb (0.18). From water to rice grains, the order is: Cu (37.26) > Zn (22.49) > Cd (6.97) > Pb (2.74) > Fe (1.94). Rice field pH and electrical conductivity favored the uptake of lead, copper and cadmium by rice grains. The findings of this study will be good documentation for risk assessment, and decision-making by environmental managers in this region.
基金the National Natural Science Foundation of China(Grant No.52270154)the National Engineering Research Center for Bioenergy,Harbin Institute of Technology,China(Grant No.2021C001).
文摘Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The results indicated that AMF significantly increased rice biomass,with an increase of up to 40.0%,particularly in root biomass by up to 68.4%.Notably,the number of prominent rice individuals also increased,and their plasticity was enhanced following AMF inoculation.AMF led to an increase in the net photosynthetic rate and antioxidant enzyme activity of rice.In the AMF treatment group,the Cd concentration in the rice roots was significantly higher(19.1%‒68.0%)compared with that in the control group.Conversely,the Cd concentration in the rice seeds was lower in the AMF treatment group,indicating that AMF facilitated the sequestration of Cd in rice roots and reduced Cd accumulation in the seeds.Path coefficients varied across different treatments,suggesting that AMF inoculation reduced the direct impact of soil Cd concentration on the total Cd accumulation in seeds.The translocation of Cd was consistently associated with simultaneous growth dilution and compensatory accumulation as a result of mycorrhizal effects.Our study quantitatively analyzed this process through path analysis and clarified the causal relationship between rice growth and Cd transfer under the influence of AMF.
基金supported by the National Natural Science Foundation of China(Grant Nos.61405058 and 62075059)the Natural Science Foundation of Hunan Province(Grant Nos.2017JJ2048 and 2020JJ4161)+2 种基金the Scientific Research Foundation of Hunan Provincial Education Department(Grant No.21A0013)the Open Project of the State Key Laboratory of Advanced Optical Communication Systems and Networks of China(Grant No.2024GZKF20)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2024A1515011353)。
文摘Hybrid skin-topological effect(HSTE)in non-Hermitian systems exhibits both the skin effect and topological protection,offering a novel mechanism for localization of topological edge states(TESs)in electrons,circuits,and photons.However,it remains unclear whether the HSTE can be realized in quasicrystals.
基金supported by the Fundamental and Commonwealth Geological Survey of Oil and Gas of China(Grant No.DD 20221662)the National Natural Science Foundation of China(NSFC)Program(Grant No.42302124).
文摘The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source rocks.However,the mechanism of organic matter(OM)enrichment throughout this period is still controversial.Based on geochemical data,the marine redox conditions,paleogeographic and hydrographic environment,primary productivity,volcanism,and terrigenous input during the Late Permian in the Lower Yangtze region have been studied from the Putaoling section,Chaohu,to provide new insights into OM accumulation.Five Phases are distinguished based on the TOC and environmental variations.In Phase I,anoxic conditions driven by water restriction enhanced OM preservation.In Phase II,euxinic and cycling hydrological environments were the two most substantial controlling factors for the massive OM deposition.During Phase III,intensified terrestrial input potentially diluted the OM in sediment and the presence of oxygen in bottom water weakened the preservation condition.Phase IV was characterized by a relatively higher abundance of mercury(Hg)and TOC(peak at 16.98 wt%),indicating that enhanced volcanism potentially stimulated higher productivity and a euxinic environment.In Phase V,extremely lean OM was preserved as a result of terrestrial dilutions and decreasing primary productivity.Phases I,II and IV are characterized as the most prominent OM-rich zones due to the effective interactions of the controlling factors,namely paleogeographic,hydrographic environment,volcanism,and redox conditions.
基金Supported by the National Natural Science Foundation of China(U22B6002)National Project for Oil and Gas Technology(2016ZX05-004)CNPC Science and Technology Project(2023ZZ02).
文摘The Ediacaran–Ordovician strata within three major marine basins(Tarim,Sichuan,and Ordos)in China are analyzed.Based on previous studies focusing on the characteristics of the Neoproterozoic–Cambrian strata within the three major basins(East Siberian,Oman,and Officer in Australia)overseas,the carbonate–evaporite assemblages in the target interval are divided into three types:intercalated carbonate and gypsum salt,interbedded carbonate and gypsum salt,and coexisted carbonate,gypsum salt and clastic rock.Moreover,the concept and definition of the carbonate-evaporite assemblage are clarified.The results indicate that the oil and gas in the carbonate-evaporite assemblage are originated from two types of source rocks:shale and argillaceous carbonate,and confirmed the capability of gypsum salt in the saline environment to drive the source rock hydrocarbon generation.The dolomite reservoirs are classified in two types:gypseous dolomite flat,and grain shoalµbial mound.This study clarifies that the penecontemporaneous or epigenic leaching of atmospheric fresh water mainly controlled the large-scale development of reservoirs.Afterwards,burial dissolution transformed and reworked the reservoirs.The hydrocarbon accumulation in carbonate-evaporite assemblage can be categorized into eight sub-models under three models(sub-evaporite hydrocarbon accumulation,supra-evaporite hydrocarbon accumulation,and inter-evaporite hydrocarbon accumulation).As a result,the Cambrian strata in the Tazhong Uplift North Slope,Maigaiti Slope and Mazatag Front Uplift Zone of the Tarim Basin,the Cambrian strata in the eastern-southern area of the Sichuan Basin,and the inter-evaporite Ma-4 Member of Ordovician in the Ordos Basin,China,are defined as favorable targets for future exploration.
基金The financial support from the National Natural Science Foun-dation of China(Grant Nos.52074299 and 41941018)the Fundamental Research Funds for the Central Universities of China(Grant No.2023JCCXSB02)are gratefully acknowledged.
文摘To investigate the mechanism of rockburst prevention by spraying water onto the surrounding rocks,15 experiments are performed considering different water absorption levels on a single face.High-speed photography and acoustic emission(AE)system are used to monitor the rockburst process.The effect of water on sandstone rockburst and the prevention mechanism of water on sandstone rockburst are analyzed from the perspective of energy and failure mode.The results show that the higher the ab-sorption degree,the lower the intensity of the rockburst after absorbing water on single side of sand-stone.This is reflected in the fact that with the increase in the water absorption level,the ejection velocity of rockburst fragments is smaller,the depth of the rockburst pit is shallower,and the AE energy is smaller.Under the water absorption level of 100%,the magnitude of rockburst intensity changes from medium to slight.The prevention mechanism of water on sandstone rockburst is that water reduces the capacity of sandstone to store strain energy and accelerates the expansion of shear cracks,which is not conducive to the occurrence of plate cracking before rockburst,and destroys the conditions for rockburst incubation.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11974071 and 62375040)the Sichuan Science and Technology Program(Grant Nos.2022ZYD0108 and 2023JDRC0030).
文摘This study investigates the properties of exciton-polaritons in a two-dimensional(2D)hybrid organic-inorganic perovskite microcavity in the presence of optical Stark effect.Through both steady and dynamic state analyses,strong coupling between excitons of perovskite and cavity photons is revealed,indicating the formation of polaritons in the perovskite microcavity.Besides,it is found that an external optical Stark pulse can induce energy shifts of excitons proportional to the pulse intensity,which modifies the dispersion characteristics of the polaritons.
