The thermoelectric properties of layered Mo_(2)AB_(2)(A=S,Se,Te;B=Cl,Br,I)materials are systematically investigated by first-principles approach.Soft transverse acoustic modes and direct Mo d–Mo d couplings give rise...The thermoelectric properties of layered Mo_(2)AB_(2)(A=S,Se,Te;B=Cl,Br,I)materials are systematically investigated by first-principles approach.Soft transverse acoustic modes and direct Mo d–Mo d couplings give rise to strong anharmonicities and low lattice thermal conductivities.The double anions with distinctly different electronegativities of Mo_(2)AB_(2)monolayers can reduce the correlation between electron transport and phonon scattering,and further benefit much to their good thermoelectric properties.Thermoelectric properties of these Mo_(2)AB_(2)monolayers exhibit obvious anisotropies due to the direction-dependent chemical bondings and transport properties.Furthermore,their thermoelectric properties strongly depend on carrier type(n-type or p-type),carrier concentration and temperature.It is found that n-type Mo_(2)AB_(2)monolayers can be excellent thermoelectric materials with high electric conductivity,σ,and figures of merit,ZT.Choosing the types of A and B anions of Mo_(2)AB_(2)is an effective strategy to optimize their thermoelectric performance.These results provide rigorous understanding on thermoelectric properties of double-anions compounds and important guidance for achieving high thermoelectric performance in multi-anion compounds.展开更多
Little is known about the association between structural gender inequality and health in patriarchal China.This study employed a sample from the Chinese Women’s Social Status,consisting of 26,139 participants aged 18...Little is known about the association between structural gender inequality and health in patriarchal China.This study employed a sample from the Chinese Women’s Social Status,consisting of 26,139 participants aged 18 and 70 years(13,494 women and 12,645 men).Structural gender inequality was assessed at the macro-,meso-,and micro-levels.Mental health was measured by the summed scores of eight questions on depressive symptoms.Multilevel linear regression was applied for analysis.Results showed that total sex ratio at birth was associated with poorer mental health among women and men but sex ratio at birth of the second-born child predicted better mental health.Gender inequality at meso-level resulted in poorer mental health and gender inequality at micro-level was associated with poorer mental health both for men and women.Eliminating structural gender inequality promotes populations’mental health in China.展开更多
High-performance materials are the key to developing new alternative energy-storage systems[1-4].Sodium ion batteries(SIBs)are regarded as the promising large-scale electric energy storage owing to the high abundance ...High-performance materials are the key to developing new alternative energy-storage systems[1-4].Sodium ion batteries(SIBs)are regarded as the promising large-scale electric energy storage owing to the high abundance and low cost of sodium resources[1,5-9].However,the sluggish kinetics of Na^(+)caused by the large-sized Na^(+)(1.02A)result in the lower energy density and unsatisfactory electrochemical properties[10-14].展开更多
Objective:To investigate the differential expression of apurinic-apyrimidinic endonuclease 1(APE1)in hepatocellular carcinoma(HCC)tissues and cells and the corresponding effects on proliferation and apoptosis of cance...Objective:To investigate the differential expression of apurinic-apyrimidinic endonuclease 1(APE1)in hepatocellular carcinoma(HCC)tissues and cells and the corresponding effects on proliferation and apoptosis of cancer cells.Methods:Immunohistochemical techniques were used to detect the expression of APE1 in 80 cases of HCC and the corresponding paracancerous tissue microarrays.展开更多
The first Mars exploration mission of China(Tianwen-1)is scheduled to be launched in 2020;a charged particle telescope,the Mars Energetic Particle Analyzer(MEPA),is carried as one of the payloads on the orbiter.The ME...The first Mars exploration mission of China(Tianwen-1)is scheduled to be launched in 2020;a charged particle telescope,the Mars Energetic Particle Analyzer(MEPA),is carried as one of the payloads on the orbiter.The MEPA is designed to measure solar energetic particles(SEPs)and galactic cosmic rays(GCRs)in the near-Mars space and in the transfer orbit from Earth to Mars.Before the launch,the MEPA was calibrated in ground experiments with radioactive sources,electronic pulses,and accelerator beams.The calibration parameters,such as energy conversion constants,threshold values for the triggers,and particle identification criteria,were determined and have been stored for onboard use.The validity of the calibration parameters has been verified with radioactive sources and beams.The calibration results indicate that the MEPA can measure charged particles reliably,as designed,and that it can satisfy the requirements of the Tianwen-1 mission.展开更多
Computational simulation is an important technical means in research of nuclear fuel materials.Since nuclear fuel issues are inherently multi-scopic,it is imperative to study them with multi-scale simulation scheme.At...Computational simulation is an important technical means in research of nuclear fuel materials.Since nuclear fuel issues are inherently multi-scopic,it is imperative to study them with multi-scale simulation scheme.At present,the development of multi-scale simulation for nuclear fuel materials calls for a more systematic approach,in which lies the main purpose of this article.The most important thing in multi-scale simulation is to accurately formulate the goals to be achieved and the types of methods to be used.In this regard,we first summarize the basic principles and applicability of the simulation methods which are commonly used in nuclear fuel research and are based on different scales ranging from micro to macro,i.e.First-Principles(FP),Molecular Dynamics(MD),Kinetic Monte Carlo(KMC),Phase Field(PF),Rate Theory(RT),and Finite Element Method(FEM).And then we discuss the major material issues in this field,also ranging from micro-scale to macro-scale and covering both pellets and claddings,with emphasis on what simulation method would be most suitable for solving each of the issues.Finally,we give our prospective analysis and understanding about the feasible ways of multi-scale integration and relevant handicaps and challenges.展开更多
Soft carbons have attracted extensive interests as competitive anodes for fast-charging sodium-ion batteries(SIBs);however,the high-rate performance is still restricted by their large ion migration barriers and sluggi...Soft carbons have attracted extensive interests as competitive anodes for fast-charging sodium-ion batteries(SIBs);however,the high-rate performance is still restricted by their large ion migration barriers and sluggish reaction kinetics.Herein,we show a molecular design approach toward the fabrication of nitrogen and phosphorus codoped mesoporous soft carbon(NPSC).The key to this strategy lies in the chemical cross-linking reaction between polyphosphoric acid and p-phenylenediamine,associated with pyrolysis induced in-situ self-activation that creates mesoporous structures and rich heteroatoms within the carbon matrix.Thanks to the enlarged interlayer spacing,reduced ion diffusion length,and plentiful active sites,the obtained NPSC delivers a superb rate capacity of 215 mAh g-1 at 10 A g-1 and an ultralong cycle life of 4,700 cycles at 5 A g^(-1).Remarkably,the full cell shows 99%capacity retention during 100 continuous cycles,and maximum energy and power densities of 191 Wh kg^(-1)and 9.2 kW kg^(-1),respectively.We believe that such a synthetic protocol could pave a novel venue to develop soft carbons with unique properties for advanced SIBs.展开更多
With the increasing popularity of electric/hybrid vehicles and the rapid development of 3C electronics,there is a growing interest in high-rate energy storage systems.The rapid development and widespread adoption of l...With the increasing popularity of electric/hybrid vehicles and the rapid development of 3C electronics,there is a growing interest in high-rate energy storage systems.The rapid development and widespread adoption of lithiumion batteries(LIBs)can be attributed to their numerous advantages,including high energy density,high operating voltage,environmental friendliness,and lack of memory effect.However,the progress of LIBs is currently hindered by the limitations of energy storage materials,which serve as vital components.Therefore,there is an urgent need to address the development of a new generation of high-rate energy storage materials in order to overcome these limitations and further advance LIB technology.Niobium-based oxides have emerged as promising candidates for the fabrication of fast-charging Li-ion batteries due to their excellent rate capability and long lifespan.This review paper provides a comprehensive analysis of the fundamentals,methodologies,and electrochemistries of niobium-based oxides,with a specific focus on the evolution and creation of crystal phases of Nb_(2)O_(5),fundamental electrochemical behavior,and modification methods including morphology modulation,composite technology,and carbon coating.Furthermore,the review explores Nb_(2)O_(5)-derived compounds and related advanced characterization techniques.Finally,the challenges and issues in the development of niobiumbased oxides for high-rate energy storage batteries are discussed,along with future research perspectives.展开更多
In active rift basins, tectonism is extremely important for sequence stratigraphic patterns, affecting both the sequence architecture and internal makeup. Sequence stratigraphic framework of a Paleogene rift successio...In active rift basins, tectonism is extremely important for sequence stratigraphic patterns, affecting both the sequence architecture and internal makeup. Sequence stratigraphic framework of a Paleogene rift succession in Qiongdongnan Basin, northern South China Sea, was built using seismic profiles, complemented by well logs and cores. One first-order and three second-order sequences were identified on the basis of basin-scale unconformities, and seven third-order sequences are defined by unconformities along the basin margins and correlative conformities within the central basin. Through unconformity analysis and backstripping procedure, the Paleogene synrift tectonic evolution of deep- water area of Qiongdongnan Basin was proved to be episodic, which can be divided into rifting stage-I, rifting stage-II and rifting stage-III. Episodic rifting resulted in the formation of various types of struc- tural slope break belts, which controlled different architectures and internal makeup of sequences. This study enhances the understanding of the control of tectonic evolution on sequence stratigraphic pat- terns and establishes relevant patterns in a typical rift basin, and further proposes the favorable sand- stone reservoirs developing in different sequence stratigraphic patterns, which will be pretty helpful for subtle pool exploration in deepwater area of petroliferous basins.展开更多
For unveiling coal-bearing source rocks in terrestrial-marine transitional sequences, the sequence stratigraphic framework and sedimentary facies of Lower Oligocene Yacheng Formation of Qiongdongnan Basin were investi...For unveiling coal-bearing source rocks in terrestrial-marine transitional sequences, the sequence stratigraphic framework and sedimentary facies of Lower Oligocene Yacheng Formation of Qiongdongnan Basin were investigated using seismic profiles, complemented by well bores and cores. Three third-order sequences are identified on the basis of unconformities on basin margins and correlative conformities in the basin center, namely SQYC3, SQYC2 and SQYC1 from bottom to top. Coal measure in Yacheng Formation of Qiongdongnan Basin were deposited within a range of facies associations from delta plain/tidal zone to neritic sea, and three types of favourable sedimentary facies associations for coal measure were established within the sequence stratigraphic framework, including braided delta plain and alluvial fan, lagoon and tidal flat, and fan delta and coastal plain facies associations. Results shown that, in the third-order sequences, coal accumulation in landward areas（such as delta plain） of the study area predominantly correlates with the early transgressive systems tract（TST） to middle highstand systems tract（HST）, while in seaward areas（such as tidal flat-lagoon） it correlates with the early TST and middle HST. The most potential coal-bearing source rocks formed where the accommodation creation rate（Ra） and the peat-accumulation rate（Rp） could reach a state of balance, which varied among different sedimentary settings. Furthermore, intense tectonic subsidence and frequent alternative marine-continental changes of Yacheng Formation during the middle rift stage were the main reasons why the coal beds shown the characteristics of multi-beds, thin single-bed, and rapidly lateral changes. The proposed sedimentary facies associations may aid in predicting distribution of coal-bearing source rocks. This study also demonstrates that controlling factors analysis using sequence stratigraphy and sedimentology may serve as an effective approach for coal-bearing characteristics in the lower exploration deepwater area of South China Sea.展开更多
The aims of this study were to observe the relationship between injury of graft and expression of redox factor-1 （Ref-1） in early period （24 h） after liver transplantation in rat model One hundred and fifty adult ...The aims of this study were to observe the relationship between injury of graft and expression of redox factor-1 （Ref-1） in early period （24 h） after liver transplantation in rat model One hundred and fifty adult male Wister rats were randomly divided into three groups including liver transplant group, sham surgery group and untreated control group. After liver transplantation, animals were sacrificed at different time points, and the changes and significance of the expression of Ref-1 were then explored by immunohistochemistry, serology and histopathology. As compared with sham surgery group and untreated control group, the expression of Ref-1 protein in transplant group was stronger in early period after liver transplantation. With pathology analysis, lots of infiltrating inflammation cells were found around the portal veins. Hepatic tissues were injury. However, the injury in sham surgery and untreated control group were comparatively slight. The serum ALT and AST levels reached the peak at 6-12 h, and decreased significantly after 12 h. These data suggested that the degree of liver injury in earlier period after transplantation peaked at 6 h and then decreased. And Ref-1 protein induced by hepatic ischemic reperfusion injury might play critical role in repairing the injury.展开更多
On September 15,2014,China National Offshore Oil Co.,Ltd announced that a high production of oil and gas flow of 1.6106 m3/d was obtained in Well LS17-2-1 in deepwater area in northern South China Sea,which is the fi...On September 15,2014,China National Offshore Oil Co.,Ltd announced that a high production of oil and gas flow of 1.6106 m3/d was obtained in Well LS17-2-1 in deepwater area in northern South China Sea,which is the first great oil and gas discovery for self-run deepwater exploration in China sea areas,and a strategic breakthrough was made in natural gas exploration in deepwater area of Lingshui sag in Qiongdongnan Basin.Under the combined action of climax of international deepwater exploration,high oil prices,national demands of China,practical needs of exploration,breakthroughs in seismic exploration and testing technologies,innovations in geological cognition and breakthroughs in deepwater operation equipment,Lingshui 17-2 gas field is discovered.Among these factors,the innovation in reservoir forming geological cognition directly promotes the discovery.The quality of seismic data in the early time is poor,so key reservoir forming conditions such as effective source rocks,high quality reservoirs and oil-gas migration pathways are unable to be ascertained;with support of new seismic acquisition and processing technology,some researches show that Lingshui sag is a successive large and deep sag with an area of 5000 km2 and the maximum thickness of Cenozoic stratum of 13 km.In the Early Oligocene,the Lingshui sag was a semi-closed delta-estuarine environment,where the coalmeasure and marine mudstones in Lower Oligocene Yacheng Formation were developed.The Lingshui sag is a sag with high temperature,and the bottom temperature of source rocks in Yacheng Formation can exceed 250C,but the simulation experiment of hydrocarbon generation at high temperature indicates that the main part of this set of source rock is still in the gas-generation window,with resources of nearly 1 trillion cubic meters,so the Lingshui sag is a hydrocarbon-rich generation sag.In the Neogene,the axial canyon channel from the Thu Bon River in Vietnam passed through the Lingshui sag,and five stages of secondary channels were developed in the axial canyon channel,where four types of reservoirs with excellent physical properties including the axial sand,lateral accretion sand,natural levee sand as well as erosion residual sand were developed,and lithologic traps or structural-lithologic traps were formed.The diapiric zone in the southern Lingshui sag connects deep source rocks in Yacheng Formation and shallow sandstones in the channels,and the migration pattern of natural gas is a T-type migration pattern,in other words,the natural gas generated from Yacheng Formation migrates vertically to the interior of the channel sandbody,and then migrates laterally in the channel reservoirs and forms the reservoirs.Innovations of geophysical exploration technologies for complicated geological conditions of deepwater areas are made,such as the detuning comprehensive quantitative amplitude hydrocarbon detection technology,which greatly improves the success rate of deepwater exploration;key technologies of deepwater safety exploratory well testing represented by the platform-dragged riser displacement technology are developed,which greatly reduces the drilling test cost.The above key exploration technologies provide a strong guarantee for the efficient exploration and development of Lingshui gas field.展开更多
Faceted interphase boundaries(IPBs)are commonly observed in lath-shaped precipitates in alloys consisting of simple face-centred cubic(fcc),body centred-cubic(bcc)or hexagonal closed packed(hcp)phases,which normally c...Faceted interphase boundaries(IPBs)are commonly observed in lath-shaped precipitates in alloys consisting of simple face-centred cubic(fcc),body centred-cubic(bcc)or hexagonal closed packed(hcp)phases,which normally contain one or two sets of parallel dislocations.The influence of these dislocations on interface migration and possible accompanying long-range strain field remain unclear.To elucidate this,we carried out atomistic simulations to investigate the dislocation-mediated migration processes of IPBs in a pure-iron system.Our results show that the migration of these IPBs is accompanied with the slip of interfacial dislocations,even in high-index slip planes,with two migration modes were observed:the first mode is the uniform migration mode that occurs only when all of the dislocations slip in a common slip plane.A shear-coupled interface migration was observed for this mode.The other interfaces propagate in the stick-slip migration mode that occurs when the dislocations glide on different slip planes,involving dislocation reaction or tangling.A quantitative relationship was established to link the atomic displacements with the dislocation structure,slip plane,and interface normal.The macroscopic shear deformation due to the effect of overall atomic displacement shows a good agreement with the results obtained based on the phenomenological theory of martensite crystallography.Our findings have general implications for the understanding of phase transformations and the surface relief effect at the atomic scale.展开更多
The collective oscillation of electrons located in the conduction band of metal nanostructures being still energized,with the energy up to the bulk plasmon frequency,are called nonequilibrium hot electrons.It can lead...The collective oscillation of electrons located in the conduction band of metal nanostructures being still energized,with the energy up to the bulk plasmon frequency,are called nonequilibrium hot electrons.It can lead to the state-filling effect in the energy band of the neighboring semiconductor.Here,we report on the incandescent-type light source composed of Au nano rods decorated with single Ga-doped ZnO microwire(AuNRs@ZnO:Ga MW).Benefiting from Au nanorods with controlled aspect ratio,wavelength-tunable incandescent-type lighting was achieved,with the dominating emission peaks tuning from visible to near-infrared spectral regions.The intrinsic mechanism was found that tunable nonequilibrium distribution of hot electrons in ZnO:Ga MW,injected from Au nanorods,can be responsible for the tuning emission features.Apart from the modification over the composition,bandgap engineering,doping level,etc.,the realization of electrically driving the generation and injection of nonequilibrium hot electrons from single ZnO:Ga MW with Au nanostructure coating may provide a promising platform to construct electronics and optoelectronics devices,such as electric spasers and hot-carrier-induced tunneling diodes.展开更多
Quantitative trait locus(QTL) mapping is frequently used to understand the genetic architecture of quantitative traits.Herein,we performed a genome scanfor QTL affecting the morphometric characters in eight full-sib f...Quantitative trait locus(QTL) mapping is frequently used to understand the genetic architecture of quantitative traits.Herein,we performed a genome scanfor QTL affecting the morphometric characters in eight full-sib families containing 522 individuals using different statistical methods(Sib-pair and half-sib model).A total of 194 QTLs were detected in 25 different regions on 10 linkage groups(LGs).Among them,37 QTLs on five LGs(eight,13,24,40 and 45) were significant(5%genome-wide level),while the remaining 40(1%chromosome-wide level) and 117(5%chromosome-wide level) indicated suggestive effect on those traits.Heritabilities for most morphometric traits were moderate to high,ranging from 0.21 to 0.66,with generally strong phenotypic and genetic correlations between the traits.A large number of QTLs for morphometric traits were co-located,consistent with their high correlations,and may reflect pleiotropic effect on the same genes.Biological pathways were mapped for possible candidate genes on QTL regions.One significantly enriched pathway was identified onLG45,which had a P-value of 0.04 and corresponded to the "regulation of actin cytoskeleton pathway".The results are expected to be useful in marker-assisted selection(MAS) and provide valuable information for the study of gene pathway for morphometric and growth traits of the common carp.展开更多
We developed a systematic non-perturbative method base on Dyson–Schwinger theory and theΦ-derivable theory for Ising model at broken phase.Based on these methods,we obtain critical temperature and spin spin correlat...We developed a systematic non-perturbative method base on Dyson–Schwinger theory and theΦ-derivable theory for Ising model at broken phase.Based on these methods,we obtain critical temperature and spin spin correlation beyond mean field theory.The spectrum of Green function obtained from our methods become gapless at critical point,so the susceptibility become divergent at Tc.The critical temperature of Ising model obtained from this method is fairly good in comparison with other non-cluster methods.It is straightforward to extend this method to more complicate spin models for example with continue symmetry.展开更多
Thyroglossal duct carcinoma,which is usually diagnosed postoperatively,is a rare malignant tumor arising in the thyroglossal duct cyst.The definitive diagnosis can be made only after microscopic examination.We retrosp...Thyroglossal duct carcinoma,which is usually diagnosed postoperatively,is a rare malignant tumor arising in the thyroglossal duct cyst.The definitive diagnosis can be made only after microscopic examination.We retrospectively reviewed three cases of thyroglossal duct carcinoma diagnosed in Peking University School and Hospital of Stomatology from January 1986 to August 2006.Clinical and pathological features were investigated and the optimal treatment protocol was proposed.The constituent ratio of thyroglossal duct carcinoma among surgically excised thyroglossal duct lesions was 2.9%.The clinical presentation of thyroglossal duct carcinoma was very similar to that of its benign counterpart.Two cases were diagnosed as thyroglossal duct cyst prior to the operation,the remaining one as dermoid cyst.All three cases were diagnosed as papillary carcinoma of thyroid origin after microscopic examination.Primary thyroglossal duct carcinoma should conform to the following criteria:localization of the carcinoma to a clearly demonstrable thyroglossal duct cyst or tract;clinically or histologically confirmed absence of carcinoma of the thyroid gland.Papillary carcinoma is the most common histological type,which usually develops slowly with an excellent prognosis.The histological characteristics including:formation of papillary structure;nuclear morphological variations such as ground glass nuclei,pseudoinclusions,intranuclear grooves and filaments;concentrically calcified structures termed psammoma bodies which is regarded as a strong indication of papillary carcinoma;and positivity in immunohistological staining for thyroglobin.Sistrunk procedure of excision is the choice for treatment.A close follow-up is needed.In the presence of thyroid gland masses or cervical lymphadenopathy,thyroidectomy or neck dissection should be recommended.The effect of thyroid suppression therapy and radioactive iodine therapy is not conclusive.展开更多
The service life of an electric vehicle is,to some extent,determined by the life of the traction battery.A good charging strat-egy has an important impact on improving the cycle life of the lithium-ion battery.Here,th...The service life of an electric vehicle is,to some extent,determined by the life of the traction battery.A good charging strat-egy has an important impact on improving the cycle life of the lithium-ion battery.Here,this paper presents a comparative study on the cycle life and material structure stability of lithium-ion batteries,based on typical charging strategies currently applied in the market,such as constant current charging,constant current and constant voltage charging,multi-stage constant current charging,variable current intermittent charging,and pulse charging.Compared with the reference charging strategy,the charging capacity of multi-stage constant current charging reaches 88%.Moreover,the charging time is reduced by 69%,and the capacity retention rate after 500 cycles is 93.3%.Through CT,XRD,SEM,and Raman spectroscopy analysis,it is confirmed that the smaller the damage caused by this charging strategy to the overall structure of the battery and the layered structure and particle size of the positive electrode material,the higher the capacity retention rate is.This work facilitates the development of a better charging strategy for a lithium-ion battery from the perspective of material structure.展开更多
基金Project supported by the Science and Technology Program of Guangzhou City(Grant Nos.202102020389 and 202103030001)the Fund of Guangdong Provincial Key Laboratory of Information Photonics Technology(Grant No.2020B121201011)the National Natural Science Foundation of China(Grant Nos.11804058 and 12064027)。
文摘The thermoelectric properties of layered Mo_(2)AB_(2)(A=S,Se,Te;B=Cl,Br,I)materials are systematically investigated by first-principles approach.Soft transverse acoustic modes and direct Mo d–Mo d couplings give rise to strong anharmonicities and low lattice thermal conductivities.The double anions with distinctly different electronegativities of Mo_(2)AB_(2)monolayers can reduce the correlation between electron transport and phonon scattering,and further benefit much to their good thermoelectric properties.Thermoelectric properties of these Mo_(2)AB_(2)monolayers exhibit obvious anisotropies due to the direction-dependent chemical bondings and transport properties.Furthermore,their thermoelectric properties strongly depend on carrier type(n-type or p-type),carrier concentration and temperature.It is found that n-type Mo_(2)AB_(2)monolayers can be excellent thermoelectric materials with high electric conductivity,σ,and figures of merit,ZT.Choosing the types of A and B anions of Mo_(2)AB_(2)is an effective strategy to optimize their thermoelectric performance.These results provide rigorous understanding on thermoelectric properties of double-anions compounds and important guidance for achieving high thermoelectric performance in multi-anion compounds.
文摘Little is known about the association between structural gender inequality and health in patriarchal China.This study employed a sample from the Chinese Women’s Social Status,consisting of 26,139 participants aged 18 and 70 years(13,494 women and 12,645 men).Structural gender inequality was assessed at the macro-,meso-,and micro-levels.Mental health was measured by the summed scores of eight questions on depressive symptoms.Multilevel linear regression was applied for analysis.Results showed that total sex ratio at birth was associated with poorer mental health among women and men but sex ratio at birth of the second-born child predicted better mental health.Gender inequality at meso-level resulted in poorer mental health and gender inequality at micro-level was associated with poorer mental health both for men and women.Eliminating structural gender inequality promotes populations’mental health in China.
基金supported by the National Natural Science Foundation of China(Nos.21905058,21663029)Guangdong University of Technology Hundred Talents Program(No.220418136)Guangdong University of Technology Youth Hundred Talents Program(No.220413671)。
文摘High-performance materials are the key to developing new alternative energy-storage systems[1-4].Sodium ion batteries(SIBs)are regarded as the promising large-scale electric energy storage owing to the high abundance and low cost of sodium resources[1,5-9].However,the sluggish kinetics of Na^(+)caused by the large-sized Na^(+)(1.02A)result in the lower energy density and unsatisfactory electrochemical properties[10-14].
文摘Objective:To investigate the differential expression of apurinic-apyrimidinic endonuclease 1(APE1)in hepatocellular carcinoma(HCC)tissues and cells and the corresponding effects on proliferation and apoptosis of cancer cells.Methods:Immunohistochemical techniques were used to detect the expression of APE1 in 80 cases of HCC and the corresponding paracancerous tissue microarrays.
基金supported by the Engineering and Technological Research Project on Civil Aerospace Technologies of the CNSA.
文摘The first Mars exploration mission of China(Tianwen-1)is scheduled to be launched in 2020;a charged particle telescope,the Mars Energetic Particle Analyzer(MEPA),is carried as one of the payloads on the orbiter.The MEPA is designed to measure solar energetic particles(SEPs)and galactic cosmic rays(GCRs)in the near-Mars space and in the transfer orbit from Earth to Mars.Before the launch,the MEPA was calibrated in ground experiments with radioactive sources,electronic pulses,and accelerator beams.The calibration parameters,such as energy conversion constants,threshold values for the triggers,and particle identification criteria,were determined and have been stored for onboard use.The validity of the calibration parameters has been verified with radioactive sources and beams.The calibration results indicate that the MEPA can measure charged particles reliably,as designed,and that it can satisfy the requirements of the Tianwen-1 mission.
基金the financial support from the China National Natural Science Foundation project(11675126)Project of China Nuclear Power Innovation Center,China National Nuclear Corporation Science fund for talented young scholars(FY18000120)the National Science and Technology Major Project of the Ministry of Science and Technology of China(2019ZX06004009).
文摘Computational simulation is an important technical means in research of nuclear fuel materials.Since nuclear fuel issues are inherently multi-scopic,it is imperative to study them with multi-scale simulation scheme.At present,the development of multi-scale simulation for nuclear fuel materials calls for a more systematic approach,in which lies the main purpose of this article.The most important thing in multi-scale simulation is to accurately formulate the goals to be achieved and the types of methods to be used.In this regard,we first summarize the basic principles and applicability of the simulation methods which are commonly used in nuclear fuel research and are based on different scales ranging from micro to macro,i.e.First-Principles(FP),Molecular Dynamics(MD),Kinetic Monte Carlo(KMC),Phase Field(PF),Rate Theory(RT),and Finite Element Method(FEM).And then we discuss the major material issues in this field,also ranging from micro-scale to macro-scale and covering both pellets and claddings,with emphasis on what simulation method would be most suitable for solving each of the issues.Finally,we give our prospective analysis and understanding about the feasible ways of multi-scale integration and relevant handicaps and challenges.
基金supported by the National Natural Science Foundation of China(22279104,51902261,and 61935017)the National Key Research and Development Program of China(2020YFA0709900)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(2020A1515110604)the Natural Science Basic Research Program of Shaanxi(2021JQ-107)the Natural Science Foundation of Ningbo(202003N4053 and 202003N4046)the Provincial Innovation and Entrepreneurship Training Program for College Students(S202110699517).
文摘Soft carbons have attracted extensive interests as competitive anodes for fast-charging sodium-ion batteries(SIBs);however,the high-rate performance is still restricted by their large ion migration barriers and sluggish reaction kinetics.Herein,we show a molecular design approach toward the fabrication of nitrogen and phosphorus codoped mesoporous soft carbon(NPSC).The key to this strategy lies in the chemical cross-linking reaction between polyphosphoric acid and p-phenylenediamine,associated with pyrolysis induced in-situ self-activation that creates mesoporous structures and rich heteroatoms within the carbon matrix.Thanks to the enlarged interlayer spacing,reduced ion diffusion length,and plentiful active sites,the obtained NPSC delivers a superb rate capacity of 215 mAh g-1 at 10 A g-1 and an ultralong cycle life of 4,700 cycles at 5 A g^(-1).Remarkably,the full cell shows 99%capacity retention during 100 continuous cycles,and maximum energy and power densities of 191 Wh kg^(-1)and 9.2 kW kg^(-1),respectively.We believe that such a synthetic protocol could pave a novel venue to develop soft carbons with unique properties for advanced SIBs.
基金This work was financially supported by“Hundred Young Talents Program”(No.263113491)from Guangdong University of Technology.
文摘With the increasing popularity of electric/hybrid vehicles and the rapid development of 3C electronics,there is a growing interest in high-rate energy storage systems.The rapid development and widespread adoption of lithiumion batteries(LIBs)can be attributed to their numerous advantages,including high energy density,high operating voltage,environmental friendliness,and lack of memory effect.However,the progress of LIBs is currently hindered by the limitations of energy storage materials,which serve as vital components.Therefore,there is an urgent need to address the development of a new generation of high-rate energy storage materials in order to overcome these limitations and further advance LIB technology.Niobium-based oxides have emerged as promising candidates for the fabrication of fast-charging Li-ion batteries due to their excellent rate capability and long lifespan.This review paper provides a comprehensive analysis of the fundamentals,methodologies,and electrochemistries of niobium-based oxides,with a specific focus on the evolution and creation of crystal phases of Nb_(2)O_(5),fundamental electrochemical behavior,and modification methods including morphology modulation,composite technology,and carbon coating.Furthermore,the review explores Nb_(2)O_(5)-derived compounds and related advanced characterization techniques.Finally,the challenges and issues in the development of niobiumbased oxides for high-rate energy storage batteries are discussed,along with future research perspectives.
基金supported by the National Science Foundation of China (NSFC) (Nos. 41272122, 41202074 and 41172123)the Major National Science and Technology Programs in the "Twelfth Five-Year" Plan of China (No. 2011ZX05009-002-02)+1 种基金the Open Research Program Foundation of Teaching Laboratory of China University of Geosciencesthe Foundation of Key Laboratory of Tectonics and Petroleum Resources (China University of Geosciences) of Ministry of Education (No. TPR-2013-14)
文摘In active rift basins, tectonism is extremely important for sequence stratigraphic patterns, affecting both the sequence architecture and internal makeup. Sequence stratigraphic framework of a Paleogene rift succession in Qiongdongnan Basin, northern South China Sea, was built using seismic profiles, complemented by well logs and cores. One first-order and three second-order sequences were identified on the basis of basin-scale unconformities, and seven third-order sequences are defined by unconformities along the basin margins and correlative conformities within the central basin. Through unconformity analysis and backstripping procedure, the Paleogene synrift tectonic evolution of deep- water area of Qiongdongnan Basin was proved to be episodic, which can be divided into rifting stage-I, rifting stage-II and rifting stage-III. Episodic rifting resulted in the formation of various types of struc- tural slope break belts, which controlled different architectures and internal makeup of sequences. This study enhances the understanding of the control of tectonic evolution on sequence stratigraphic pat- terns and establishes relevant patterns in a typical rift basin, and further proposes the favorable sand- stone reservoirs developing in different sequence stratigraphic patterns, which will be pretty helpful for subtle pool exploration in deepwater area of petroliferous basins.
基金supported by the Zhanjiang Branch of CNOOC Ltd.the National Science and Technology Projects (No. 2011ZX05025-002-02-02)+1 种基金Natural Science Foundation of China (NSFC) (Nos. 41202074 and 41272122)the Key Laboratory of Tectonics and Petroleum Resources (CUG) of Ministry of Education Open Issue (No. TPR-2013-13)
文摘For unveiling coal-bearing source rocks in terrestrial-marine transitional sequences, the sequence stratigraphic framework and sedimentary facies of Lower Oligocene Yacheng Formation of Qiongdongnan Basin were investigated using seismic profiles, complemented by well bores and cores. Three third-order sequences are identified on the basis of unconformities on basin margins and correlative conformities in the basin center, namely SQYC3, SQYC2 and SQYC1 from bottom to top. Coal measure in Yacheng Formation of Qiongdongnan Basin were deposited within a range of facies associations from delta plain/tidal zone to neritic sea, and three types of favourable sedimentary facies associations for coal measure were established within the sequence stratigraphic framework, including braided delta plain and alluvial fan, lagoon and tidal flat, and fan delta and coastal plain facies associations. Results shown that, in the third-order sequences, coal accumulation in landward areas（such as delta plain） of the study area predominantly correlates with the early transgressive systems tract（TST） to middle highstand systems tract（HST）, while in seaward areas（such as tidal flat-lagoon） it correlates with the early TST and middle HST. The most potential coal-bearing source rocks formed where the accommodation creation rate（Ra） and the peat-accumulation rate（Rp） could reach a state of balance, which varied among different sedimentary settings. Furthermore, intense tectonic subsidence and frequent alternative marine-continental changes of Yacheng Formation during the middle rift stage were the main reasons why the coal beds shown the characteristics of multi-beds, thin single-bed, and rapidly lateral changes. The proposed sedimentary facies associations may aid in predicting distribution of coal-bearing source rocks. This study also demonstrates that controlling factors analysis using sequence stratigraphy and sedimentology may serve as an effective approach for coal-bearing characteristics in the lower exploration deepwater area of South China Sea.
文摘The aims of this study were to observe the relationship between injury of graft and expression of redox factor-1 （Ref-1） in early period （24 h） after liver transplantation in rat model One hundred and fifty adult male Wister rats were randomly divided into three groups including liver transplant group, sham surgery group and untreated control group. After liver transplantation, animals were sacrificed at different time points, and the changes and significance of the expression of Ref-1 were then explored by immunohistochemistry, serology and histopathology. As compared with sham surgery group and untreated control group, the expression of Ref-1 protein in transplant group was stronger in early period after liver transplantation. With pathology analysis, lots of infiltrating inflammation cells were found around the portal veins. Hepatic tissues were injury. However, the injury in sham surgery and untreated control group were comparatively slight. The serum ALT and AST levels reached the peak at 6-12 h, and decreased significantly after 12 h. These data suggested that the degree of liver injury in earlier period after transplantation peaked at 6 h and then decreased. And Ref-1 protein induced by hepatic ischemic reperfusion injury might play critical role in repairing the injury.
基金The work was supported by China National Significant Science and Technology Project(No.2008ZX05025,No.2011ZX05025,No.2016ZX05026)China National Key Basic Research and Development Program(973 Program)(2009CB219400)Project of Ministry of Land and Resources of the People's Republic of China(XQ2004-05,XQ2007-05).
文摘On September 15,2014,China National Offshore Oil Co.,Ltd announced that a high production of oil and gas flow of 1.6106 m3/d was obtained in Well LS17-2-1 in deepwater area in northern South China Sea,which is the first great oil and gas discovery for self-run deepwater exploration in China sea areas,and a strategic breakthrough was made in natural gas exploration in deepwater area of Lingshui sag in Qiongdongnan Basin.Under the combined action of climax of international deepwater exploration,high oil prices,national demands of China,practical needs of exploration,breakthroughs in seismic exploration and testing technologies,innovations in geological cognition and breakthroughs in deepwater operation equipment,Lingshui 17-2 gas field is discovered.Among these factors,the innovation in reservoir forming geological cognition directly promotes the discovery.The quality of seismic data in the early time is poor,so key reservoir forming conditions such as effective source rocks,high quality reservoirs and oil-gas migration pathways are unable to be ascertained;with support of new seismic acquisition and processing technology,some researches show that Lingshui sag is a successive large and deep sag with an area of 5000 km2 and the maximum thickness of Cenozoic stratum of 13 km.In the Early Oligocene,the Lingshui sag was a semi-closed delta-estuarine environment,where the coalmeasure and marine mudstones in Lower Oligocene Yacheng Formation were developed.The Lingshui sag is a sag with high temperature,and the bottom temperature of source rocks in Yacheng Formation can exceed 250C,but the simulation experiment of hydrocarbon generation at high temperature indicates that the main part of this set of source rock is still in the gas-generation window,with resources of nearly 1 trillion cubic meters,so the Lingshui sag is a hydrocarbon-rich generation sag.In the Neogene,the axial canyon channel from the Thu Bon River in Vietnam passed through the Lingshui sag,and five stages of secondary channels were developed in the axial canyon channel,where four types of reservoirs with excellent physical properties including the axial sand,lateral accretion sand,natural levee sand as well as erosion residual sand were developed,and lithologic traps or structural-lithologic traps were formed.The diapiric zone in the southern Lingshui sag connects deep source rocks in Yacheng Formation and shallow sandstones in the channels,and the migration pattern of natural gas is a T-type migration pattern,in other words,the natural gas generated from Yacheng Formation migrates vertically to the interior of the channel sandbody,and then migrates laterally in the channel reservoirs and forms the reservoirs.Innovations of geophysical exploration technologies for complicated geological conditions of deepwater areas are made,such as the detuning comprehensive quantitative amplitude hydrocarbon detection technology,which greatly improves the success rate of deepwater exploration;key technologies of deepwater safety exploratory well testing represented by the platform-dragged riser displacement technology are developed,which greatly reduces the drilling test cost.The above key exploration technologies provide a strong guarantee for the efficient exploration and development of Lingshui gas field.
基金financially supported by the National Natural Science Foundation of China (Nos.51471097 and 51671111)the National Key Research and Development Program of China (No. 2016YFB0701304)
文摘Faceted interphase boundaries(IPBs)are commonly observed in lath-shaped precipitates in alloys consisting of simple face-centred cubic(fcc),body centred-cubic(bcc)or hexagonal closed packed(hcp)phases,which normally contain one or two sets of parallel dislocations.The influence of these dislocations on interface migration and possible accompanying long-range strain field remain unclear.To elucidate this,we carried out atomistic simulations to investigate the dislocation-mediated migration processes of IPBs in a pure-iron system.Our results show that the migration of these IPBs is accompanied with the slip of interfacial dislocations,even in high-index slip planes,with two migration modes were observed:the first mode is the uniform migration mode that occurs only when all of the dislocations slip in a common slip plane.A shear-coupled interface migration was observed for this mode.The other interfaces propagate in the stick-slip migration mode that occurs when the dislocations glide on different slip planes,involving dislocation reaction or tangling.A quantitative relationship was established to link the atomic displacements with the dislocation structure,slip plane,and interface normal.The macroscopic shear deformation due to the effect of overall atomic displacement shows a good agreement with the results obtained based on the phenomenological theory of martensite crystallography.Our findings have general implications for the understanding of phase transformations and the surface relief effect at the atomic scale.
基金National Natural Science Foundation of China(11574307,11774171,11874220,21805137,U160426311974182)+2 种基金Excellent Young Talents Fund Program of Higher Education Institutions of Jiangsu Province(KYZZ16-0164)China National Funds for Distinguished Young Scientists(11727902,61425021,61525404)100 Talents Program of the Chinese Academy of Sciences。
文摘The collective oscillation of electrons located in the conduction band of metal nanostructures being still energized,with the energy up to the bulk plasmon frequency,are called nonequilibrium hot electrons.It can lead to the state-filling effect in the energy band of the neighboring semiconductor.Here,we report on the incandescent-type light source composed of Au nano rods decorated with single Ga-doped ZnO microwire(AuNRs@ZnO:Ga MW).Benefiting from Au nanorods with controlled aspect ratio,wavelength-tunable incandescent-type lighting was achieved,with the dominating emission peaks tuning from visible to near-infrared spectral regions.The intrinsic mechanism was found that tunable nonequilibrium distribution of hot electrons in ZnO:Ga MW,injected from Au nanorods,can be responsible for the tuning emission features.Apart from the modification over the composition,bandgap engineering,doping level,etc.,the realization of electrically driving the generation and injection of nonequilibrium hot electrons from single ZnO:Ga MW with Au nanostructure coating may provide a promising platform to construct electronics and optoelectronics devices,such as electric spasers and hot-carrier-induced tunneling diodes.
基金supported by the National Natural Science Foundation of China(31302174)the Central-Level Non-profit Scientific Research Institutes Special Funds(HSY201303)the China Ministry of Agriculture Recommend International Advanced Agricultural Science and Technology Plan(2016-X15)
文摘Quantitative trait locus(QTL) mapping is frequently used to understand the genetic architecture of quantitative traits.Herein,we performed a genome scanfor QTL affecting the morphometric characters in eight full-sib families containing 522 individuals using different statistical methods(Sib-pair and half-sib model).A total of 194 QTLs were detected in 25 different regions on 10 linkage groups(LGs).Among them,37 QTLs on five LGs(eight,13,24,40 and 45) were significant(5%genome-wide level),while the remaining 40(1%chromosome-wide level) and 117(5%chromosome-wide level) indicated suggestive effect on those traits.Heritabilities for most morphometric traits were moderate to high,ranging from 0.21 to 0.66,with generally strong phenotypic and genetic correlations between the traits.A large number of QTLs for morphometric traits were co-located,consistent with their high correlations,and may reflect pleiotropic effect on the same genes.Biological pathways were mapped for possible candidate genes on QTL regions.One significantly enriched pathway was identified onLG45,which had a P-value of 0.04 and corresponded to the "regulation of actin cytoskeleton pathway".The results are expected to be useful in marker-assisted selection(MAS) and provide valuable information for the study of gene pathway for morphometric and growth traits of the common carp.
基金The work was supported by the National Natural Science Foundation of China(Grant Nos.11674007,91736208,and 11920101004)。
文摘We developed a systematic non-perturbative method base on Dyson–Schwinger theory and theΦ-derivable theory for Ising model at broken phase.Based on these methods,we obtain critical temperature and spin spin correlation beyond mean field theory.The spectrum of Green function obtained from our methods become gapless at critical point,so the susceptibility become divergent at Tc.The critical temperature of Ising model obtained from this method is fairly good in comparison with other non-cluster methods.It is straightforward to extend this method to more complicate spin models for example with continue symmetry.
文摘Thyroglossal duct carcinoma,which is usually diagnosed postoperatively,is a rare malignant tumor arising in the thyroglossal duct cyst.The definitive diagnosis can be made only after microscopic examination.We retrospectively reviewed three cases of thyroglossal duct carcinoma diagnosed in Peking University School and Hospital of Stomatology from January 1986 to August 2006.Clinical and pathological features were investigated and the optimal treatment protocol was proposed.The constituent ratio of thyroglossal duct carcinoma among surgically excised thyroglossal duct lesions was 2.9%.The clinical presentation of thyroglossal duct carcinoma was very similar to that of its benign counterpart.Two cases were diagnosed as thyroglossal duct cyst prior to the operation,the remaining one as dermoid cyst.All three cases were diagnosed as papillary carcinoma of thyroid origin after microscopic examination.Primary thyroglossal duct carcinoma should conform to the following criteria:localization of the carcinoma to a clearly demonstrable thyroglossal duct cyst or tract;clinically or histologically confirmed absence of carcinoma of the thyroid gland.Papillary carcinoma is the most common histological type,which usually develops slowly with an excellent prognosis.The histological characteristics including:formation of papillary structure;nuclear morphological variations such as ground glass nuclei,pseudoinclusions,intranuclear grooves and filaments;concentrically calcified structures termed psammoma bodies which is regarded as a strong indication of papillary carcinoma;and positivity in immunohistological staining for thyroglobin.Sistrunk procedure of excision is the choice for treatment.A close follow-up is needed.In the presence of thyroid gland masses or cervical lymphadenopathy,thyroidectomy or neck dissection should be recommended.The effect of thyroid suppression therapy and radioactive iodine therapy is not conclusive.
基金supported by National Key R&D Program of China(2021YFB2501500)Young Elite Scientists Sponsorship Program by CAST(2021QNRC001)Key R&D Program of Tianjin(20JCZDJC00520).
文摘The service life of an electric vehicle is,to some extent,determined by the life of the traction battery.A good charging strat-egy has an important impact on improving the cycle life of the lithium-ion battery.Here,this paper presents a comparative study on the cycle life and material structure stability of lithium-ion batteries,based on typical charging strategies currently applied in the market,such as constant current charging,constant current and constant voltage charging,multi-stage constant current charging,variable current intermittent charging,and pulse charging.Compared with the reference charging strategy,the charging capacity of multi-stage constant current charging reaches 88%.Moreover,the charging time is reduced by 69%,and the capacity retention rate after 500 cycles is 93.3%.Through CT,XRD,SEM,and Raman spectroscopy analysis,it is confirmed that the smaller the damage caused by this charging strategy to the overall structure of the battery and the layered structure and particle size of the positive electrode material,the higher the capacity retention rate is.This work facilitates the development of a better charging strategy for a lithium-ion battery from the perspective of material structure.
