Figure 3 in the paper[Chin.Phys.B 34020701(2025)]contains an axis labeling error.The revised figure is provided.This modification does not affect the result presented in the paper.
Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we...Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we perform systematic studies on the elastic properties of the Cu–6wt% Ag alloy wire, which is a promising candidate material for the new-generation pulsed magnets, by employing two independent ultrasonic techniques, i.e., resonant ultrasound spectroscopy(RUS) and ultrasound pulse-echo experiments. Our RUS measurements manifest that the elastic properties of the Cu–6wt% Ag alloy wires can be improved by an electroplastic drawing procedure as compared with the conventional cold drawing. We also take this opportunity to test the availability of our newly-built ultrasound pulse-echo facility at the Wuhan National High Magnetic Field Center(WHMFC, China), and the results suggest that the elastic performance of the electroplastically-drawn Cu–6wt% Ag alloy wire remains excellent without anomalous softening under extreme conditions,e.g., in ultra-high magnetic field up to 50 T and nitrogen or helium cryogenic liquids.展开更多
In recent years,studies focusing on the conversion of renewable lignin-derived oxygenates(LDOs)have emphasized their potential as alternatives to fossil-based products.However,LDOs,existing as complex aromatic mixture...In recent years,studies focusing on the conversion of renewable lignin-derived oxygenates(LDOs)have emphasized their potential as alternatives to fossil-based products.However,LDOs,existing as complex aromatic mixtures with diverse oxygen-containing functional groups,pose a challenge as they cannot be easily separated via distillation for direct utilization.A promising solution to this challenge lies in the efficient removal of oxygen-containing functional groups from LDOs through hydrodeoxygenation(HDO),aiming to yield biomass products with singular components.However,the high dissociation energy of the carbon-oxygen bond,coupled with its similarity to the hydrogenation energy of the benzene ring,creates a competition between deoxygenation and benzene ring hydrogenation.Considering hydrogen consumption and lignin properties,the preference is directed towards generating aromatic hydrocarbons rather than saturated components.Thus,the goal is to selectively remove oxygen-containing functional groups while preserving the benzene ring structure.Studies on LDOs conversion have indicated that the design of active components and optimization of reaction conditions play pivotal roles in achieving selective deoxygenation,but a summary of the correlation between these factors and the reaction mechanism is lacking.This review addresses this gap in knowledge by firstly summarizing the various reaction pathways for HDO of LDOs.It explores the impact of catalyst design strategies,including morphology modulation,elemental doping,and surface modification,on the adsorption-desorption dynamics between reactants and catalysts.Secondly,we delve into the application of advanced techniques such as spectroscopic techniques and computational modeling,aiding in uncovering the true active sites in HDO reactions and understanding the interaction of reactive reactants with catalyst surface-interfaces.Additionally,fundamental insights into selective deoxygenation obtained through these techniques are highlighted.Finally,we outline the challenges that lie ahead in the design of highly active and selective HDO catalysts.These challenges include the development of detection tools for reactive species with high activity at low concentrations,the study of reaction medium-catalyst interactions,and the development of theoretical models that more closely approximate real reaction situations.Addressing these challenges will pave the way for the development of efficient and selective HDO catalysts,thus advancing the field of renewable LDOs conversion.展开更多
Rechargeable battery cycling performance and related safety have been persistent concerns.It is crucial to decipher the capacity fading induced by electrode material failure via a range of techniques.Among these,synch...Rechargeable battery cycling performance and related safety have been persistent concerns.It is crucial to decipher the capacity fading induced by electrode material failure via a range of techniques.Among these,synchrotron-based X-ray techniques with high flux and brightness play a key role in understanding degradation mechanisms.In this comprehensive review,we summarize recent advancements in degra-dation modes and mechanisms that were revealed by synchrotron X-ray methodologies.Subsequently,an overview of X-ray absorption spectroscopy and X-ray scattering techniques is introduced for charac-terizing failure phenomena at local coordination atomic environment and long-range order crystal struc-ture scale,respectively.At last,we envision the future of exploring material failure mechanism.展开更多
Manipulating the expression of synaptic plasticity of neuromorphic devices provides fascinating opportunities to develop hardware platforms for artifi-cial intelligence.However,great efforts have been devoted to explo...Manipulating the expression of synaptic plasticity of neuromorphic devices provides fascinating opportunities to develop hardware platforms for artifi-cial intelligence.However,great efforts have been devoted to exploring biomimetic mechanisms of plasticity simulation in the last few years.Recent progress in various plasticity modulation techniques has pushed the research of synaptic electronics from static plasticity simulation to dynamic plasticity modulation,improving the accuracy of neuromorphic computing and providing strategies for implementing neuromorphic sensing functions.Herein,several fascinating strategies for synap-tic plasticity modulation through chemical techniques,device structure design,and physical signal sensing are reviewed.For chemical techniques,the underly-ing mechanisms for the modification of functional materials were clarified and its effect on the expression of synaptic plasticity was also highlighted.Based on device structure design,the reconfigurable operation of neuromorphic devices was well demonstrated to achieve programmable neuromorphic functions.Besides,integrating the sensory units with neuromorphic processing circuits paved a new way to achieve human-like intelligent perception under the modulation of physical signals such as light,strain,and temperature.Finally,considering that the relevant technology is still in the basic exploration stage,some prospects or development suggestions are put forward to promote the development of neuromorphic devices.展开更多
In this study, an integrated approach for diagenetic facies classification, reservoir quality analysis and quantitative wireline log prediction of tight gas sandstones(TGSs) is introduced utilizing a combination of fi...In this study, an integrated approach for diagenetic facies classification, reservoir quality analysis and quantitative wireline log prediction of tight gas sandstones(TGSs) is introduced utilizing a combination of fit-for-purpose complementary testing and machine learning techniques. The integrated approach is specialized for the middle Permian Shihezi Formation TGSs in the northeastern Ordos Basin, where operators often face significant drilling uncertainty and increased exploration risks due to low porosities and micro-Darcy range permeabilities. In this study, detrital compositions and diagenetic minerals and their pore type assemblages were analyzed using optical light microscopy, cathodoluminescence, standard scanning electron microscopy, and X-ray diffraction. Different types of diagenetic facies were delineated on this basis to capture the characteristic rock properties of the TGSs in the target formation.A combination of He porosity and permeability measurements, mercury intrusion capillary pressure and nuclear magnetic resonance data was used to analyze the mechanism of heterogeneous TGS reservoirs.We found that the type, size and proportion of pores considerably varied between diagenetic facies due to differences in the initial depositional attributes and subsequent diagenetic alterations;these differences affected the size, distribution and connectivity of the pore network and varied the reservoir quality. Five types of diagenetic facies were classified:(i) grain-coating facies, which have minimal ductile grains, chlorite coatings that inhibit quartz overgrowths, large intergranular pores that dominate the pore network, the best pore structure and the greatest reservoir quality;(ii) quartz-cemented facies,which exhibit strong quartz overgrowths, intergranular porosity and a pore size decrease, resulting in the deterioration of the pore structure and reservoir quality;(iii) mixed-cemented facies, in which the cementation of various authigenic minerals increases the micropores, resulting in a poor pore structure and reservoir quality;(iv) carbonate-cemented facies and(v) tightly compacted facies, in which the intergranular pores are filled with carbonate cement and ductile grains;thus, the pore network mainly consists of micropores with small pore throat sizes, and the pore structure and reservoir quality are the worst. The grain-coating facies with the best reservoir properties are more likely to have high gas productivity and are the primary targets for exploration and development. The diagenetic facies were then translated into wireline log expressions(conventional and NMR logging). Finally, a wireline log quantitative prediction model of TGSs using convolutional neural network machine learning algorithms was established to successfully classify the different diagenetic facies.展开更多
Advanced imaging techniques have been widely used in various biological studies.Currently,numerous imaging modalities are utilized in biological applications,including medical imaging,diagnosis,biometrics,and fundamen...Advanced imaging techniques have been widely used in various biological studies.Currently,numerous imaging modalities are utilized in biological applications,including medical imaging,diagnosis,biometrics,and fundamental biological research.Consequently,the demand for faster,clearer,and more accurate imaging techniques to support sophisticated biological studies has increased.However,there is a limitation in enhancing performance of imaging devices owing to the system complexity associated with bulky conventional optical elements.To address this issue,metasurfaces,which are flat and compact optical elements,have been considered potential candidates for biological imaging.Here,we comprehensively discuss the metasurface empowered various imaging applications in biology,including their working principles and design strategies.Furthermore,we compared conventional imaging modalities with the metasurface-based imaging system.Finally,we discuss the current challenges and offer future perspectives on metasurfaces.展开更多
This paper presents the survey and assessment of the estimation techniques on hydrodynamic impact. The description and definition of hydrodynamic impact are presented, and the categorization of prediction techniques a...This paper presents the survey and assessment of the estimation techniques on hydrodynamic impact. The description and definition of hydrodynamic impact are presented, and the categorization of prediction techniques and the difficulties are discussed. Analysis theories and numerical simulation techniques are reviewed and the characteristics of those theories and approaches are analyzed. The efforts are made to pinpoint the advantages and disadvantages. Recommendations for further research and development are made.展开更多
Although the genetic algorithm (GA) has very powerful robustness and fitness, it needs a large size of population and a large number of iterations to reach the optimum result. Especially when GA is used in complex str...Although the genetic algorithm (GA) has very powerful robustness and fitness, it needs a large size of population and a large number of iterations to reach the optimum result. Especially when GA is used in complex structural optimization problems, if the structural reanalysis technique is not adopted, the more the number of finite element analysis (FEA) is, the more the consuming time is. In the conventional structural optimization the number of FEA can be reduced by the structural reanalysis technique based on the approximation techniques and sensitivity analysis. With these techniques, this paper provides a new approximation model-segment approximation model, adopted for the GA application. This segment approximation model can decrease the number of FEA and increase the convergence rate of GA. So it can apparently decrease the computation time of GA. Two examples demonstrate the availability of the new segment approximation model.展开更多
The literature in 20th century is mainly characterized by irrationalism presented in modernism. Under the background, this paper aims to explore how Eliot attempts to use modern art techniques in The Waste Land to rev...The literature in 20th century is mainly characterized by irrationalism presented in modernism. Under the background, this paper aims to explore how Eliot attempts to use modern art techniques in The Waste Land to reveal a real life to readers.展开更多
Most overseas tourists get the first impression of the place they will visit from tourist materials.Therefore,good translations of tourist materials become one of the key factors which attract overseas tourists.The tr...Most overseas tourists get the first impression of the place they will visit from tourist materials.Therefore,good translations of tourist materials become one of the key factors which attract overseas tourists.The translating techniques,such as Transcription,Addition,Omission,Rewriting,can help translators produce good translations.展开更多
This paper presents four teaching techniques of activating the textbook for intensive reading which include:injecting contemporary elements into the text,relating the text to students' life,questioning about the t...This paper presents four teaching techniques of activating the textbook for intensive reading which include:injecting contemporary elements into the text,relating the text to students' life,questioning about the text challengingly and ingeniously,and spicing up the text.展开更多
Wuthering Heights has been one of the most famous novels in English literature. Emily's writing skills are worth the exploration. She can successfully handle the events out of chronological order; she can master t...Wuthering Heights has been one of the most famous novels in English literature. Emily's writing skills are worth the exploration. She can successfully handle the events out of chronological order; she can master the multiple narrator technique; she can create such repetitions of plots and she can design many meaningful symbols. No wonder why Wuthering Heights is in the a high position in the world literature.展开更多
The onshore oil and gas exploration has stepped into a new stage in China, with equal attention paid to both stratigraphic and subtle reservoirs and structural reservoirs. In the past few years, the increases in oil r...The onshore oil and gas exploration has stepped into a new stage in China, with equal attention paid to both stratigraphic and subtle reservoirs and structural reservoirs. In the past few years, the increases in oil reserves in most basins were found mainly in the stratigraphic and subtle reservoirs. Latest resource evaluation shows that the onshore stratigraphic and subtle reservoirs in China account for 42% of the total remaining resource, the highest in the four major exploration regions. Therefore, these reservoirs will be the most practical, potential and prevalent fields for long-lasting oil and gas exploration in onshore China. Among PetroChina's annual oil geologic reserves of 4.3 × 108t^4.6× 108t, the stratigraphic and subtle reservoirs account for more than 50%. In such basins as Songliao, Ordos, Bohai Bay, Junggar, Tarim, Sichuan and Erlian basins, stratigraphic and subtle reservoirs with geologic reserves ranging from 5×107t to 3×108t were discovered, including Ansai, Jing'an, Daqingzijing, Liuxi, well-21 area in Shinan, and Hadexun. Stratigraphic and subtle reservoirs in the four types of inland basins differ from each other in the formation conditions and the distribution patterns. While continental basins are controlled by unconformity surface, maximum flooding surface and fracture surface, the Paleozoic marine basins are influenced by paleouplift, unconformity surface, and fluctuation of the sea level. Through exploration practices and research, PetroChina has formed its own technique series focused on 3-D seismics and sequence stratigraphy.展开更多
The Ordos basin is a stable craton whose late Paleozoic undergoes two sedimentary stages: from the middle- late Carboniferous offshore plain to the Permian continental river and lake delta. Sandstones in delta plain c...The Ordos basin is a stable craton whose late Paleozoic undergoes two sedimentary stages: from the middle- late Carboniferous offshore plain to the Permian continental river and lake delta. Sandstones in delta plain channels, delta-front river mouth bars and tidal channels are well developed. The sandstones are distributed on or between the genetic source rocks, forming good gas source conditions with widespread subtle lithologic gas pools of low porosity, low permeability, low pressure and low abundance. In recent years, a series of experiments has been done, aimed at overcoming difficulties in the exploration of lithologic gas pools. A set of exploration techniques, focusing on geological appraisal, seismic exploration, accurate logging evaluation and interpretation, well testing fracturing, has been developed to guide the exploration into the upper Paleozoic in the basin, leading to the discoveries of four large gas fields: Sulige, Yulin, Wushenqi and Mizhi.展开更多
During the past decades,Li-ion batteries have been one of the most important energy storage devices.Large-scale energy storage requires Li-ion batteries which possess high energy density,low cost,and high safety.Other...During the past decades,Li-ion batteries have been one of the most important energy storage devices.Large-scale energy storage requires Li-ion batteries which possess high energy density,low cost,and high safety.Other than advanced battery materials,in-depth understanding of the intrinsic mechanism correlated with cell reaction is also essential for the development of high-performance Li-ion battery.Advanced characterization techniques,especially neutron-based techniques,have greatly promoted Li-ion battery researches.In this review,the characteristics or capabilities of various neutron-based characterization techniques,including elastic neutron scattering,quasi-elastic neutron scattering,neutron imaging,and inelastic neutron scattering,for the related Li-ion-battery researches are summarized.The design of in-situ/operando environment is also discussed.The comprehensive survey on neutron-based characterizations for mechanism understanding will provide guidance for the further study of high-performance Li-ion batteries.展开更多
Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applica...Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applications and novel devices constructed in recent years are necessary to be reviewed for inspiring subsequent studies.Hence,we summarize the progress of in-situ/operando techniques employed in rechargeable batteries.The members of this large family are divided into three sections for introduction,including bulk material,electrolyte/electrode interface and gas evolution.In each part,various energy-storage systems are mentioned and the related experimental details as well as data analysis are discussed.The simultaneous strategies of various in-situ methods are highlighted as well.Finally,current challenges and potential solutions are concluded towards the rising influence and enlarged appliance of in-situ/operando techniques in the battery research.展开更多
The increased use of rechargeable batteries in portable electronic devices and the continuous develop-ment of novel applications （e.g. transportation and large scale energy storage）, have raised a strong de-mand for...The increased use of rechargeable batteries in portable electronic devices and the continuous develop-ment of novel applications （e.g. transportation and large scale energy storage）, have raised a strong de-mand for high performance batteries with increased energy density, cycle and calendar life, safety andlower costs. This triggers significant efforts to reveal the fundamental mechanism determining batteryperformance with the use of advanced analytical techniques. However, the inherently complex character-istics of battery systems make the mechanism analysis sophisticated and difficult. Synchrotron radiationis an advanced collimated light source with high intensity and tunable energies. It has particular ad-vantages in electronic structure and geometric structure （both the short-range and long-range structure）analysis of materials on different length and time scales. In the past decades, synchrotron X-ray tech-niques have been widely used to understand the fundamental mechanism and guide the technologicaloptimization of batteries. In particular, in situ and operando techniques with high spatial and temporalresolution, enable the nondestructive, real time dynamic investigation of the electrochemical reaction,and lead to significant deep insights into the battery operation mechanism. This review gives a brief introduction of the application of synchrotron X-ray techniques to the inves-tigation of battery systems. The five widely implicated techniques, including X-ray diffraction （XRD）, PairDistribution Function （PDF）, Hard and Soft X-ray absorption spectroscopy （XAS） and X-ray photoelectronspectroscopy （XPS） will be reviewed, with the emphasis on their in situ studies of battery systems during cycling.展开更多
Thermoelectric materials have aroused widespread concern due to their unique ability to directly convert heat to electricity without any moving parts or noxious emissions.Taking advantages of two-dimensional structure...Thermoelectric materials have aroused widespread concern due to their unique ability to directly convert heat to electricity without any moving parts or noxious emissions.Taking advantages of two-dimensional structures of thermoelectric films,the potential applications of thermoelectric materials are diversified,particularly in microdevices.Well-controlled nanostructures in thermoelectric films are effective to optimize the electrical and thermal transport,which can significantly improve the performance of thermoelectric materials.In this paper,various physical and chemical approaches to fabricate thermoelectric films,including inorganic,organic,and inorganic–organic composites,are summarized,where more attentions are paid on the inorganic thermoelectric films for their excellent thermoelectric responses.Additionally,strategies for enhancing the performance of thermoelectric films are also discussed.展开更多
In this paper we investigate two techniques for single event effect(SEE) mitigation by using back junction and p^+buffer layer in non-deep trench isolation(DTI) domestic silicon–germanium heterojunction bipolar trans...In this paper we investigate two techniques for single event effect(SEE) mitigation by using back junction and p^+buffer layer in non-deep trench isolation(DTI) domestic silicon–germanium heterojunction bipolar transistors(SiGe HBTs)based on technology computer aided design(TCAD) simulation. The effectiveness of the two mitigation techniques and the influence of various structure parameters are investigated. Simulation results indicate that the two techniques are more effective in reducing collector charge collection induced by heavy ions striking at positions outside the collector–substrate(C–S) junction where charge collection is dominated by diffusion. By properly adjusting the parameters, charge collection of events outside the C–S junction can be reduced by more than an order of magnitude, while charge collection of events in the device center is halved without affecting the direct current(DC) and alternating current(AC) characteristics of the SiGe HBTs.展开更多
文摘Figure 3 in the paper[Chin.Phys.B 34020701(2025)]contains an axis labeling error.The revised figure is provided.This modification does not affect the result presented in the paper.
基金Project supported by the National Key R&D Program of China (Grant Nos. 2022YFA1602602 and 2023YFA1609600)the National Natural Science Foundation of China (Grant No. U23A20580)+3 种基金the open research fund of Songshan Lake Materials Laboratory (Grant No. 2022SLABFN27)Beijing National Laboratory for Condensed Matter Physics (Grant No. 2024BNLCMPKF004)Guangdong Basic and Applied Basic Research Foundation (Grant No. 2022B1515120020)the interdisciplinary program of Wuhan National High Magnetic Field Center at Huazhong University of Science and Technology (Grant No. WHMFC202132)。
文摘Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we perform systematic studies on the elastic properties of the Cu–6wt% Ag alloy wire, which is a promising candidate material for the new-generation pulsed magnets, by employing two independent ultrasonic techniques, i.e., resonant ultrasound spectroscopy(RUS) and ultrasound pulse-echo experiments. Our RUS measurements manifest that the elastic properties of the Cu–6wt% Ag alloy wires can be improved by an electroplastic drawing procedure as compared with the conventional cold drawing. We also take this opportunity to test the availability of our newly-built ultrasound pulse-echo facility at the Wuhan National High Magnetic Field Center(WHMFC, China), and the results suggest that the elastic performance of the electroplastically-drawn Cu–6wt% Ag alloy wire remains excellent without anomalous softening under extreme conditions,e.g., in ultra-high magnetic field up to 50 T and nitrogen or helium cryogenic liquids.
基金supported by the National Natural Science Foundation of China,Pilot Group Program of the Research Fund for International Senior Scientists(22250710676)National Natural Science Foundation of China(22078064,22378062,22304028)+1 种基金Natural Science Foundation of Fujian Province(2021J02009)Tianjin University-Fuzhou University Independent Innovation Fund Cooperation Project(TF2023-1,TF2023-8).
文摘In recent years,studies focusing on the conversion of renewable lignin-derived oxygenates(LDOs)have emphasized their potential as alternatives to fossil-based products.However,LDOs,existing as complex aromatic mixtures with diverse oxygen-containing functional groups,pose a challenge as they cannot be easily separated via distillation for direct utilization.A promising solution to this challenge lies in the efficient removal of oxygen-containing functional groups from LDOs through hydrodeoxygenation(HDO),aiming to yield biomass products with singular components.However,the high dissociation energy of the carbon-oxygen bond,coupled with its similarity to the hydrogenation energy of the benzene ring,creates a competition between deoxygenation and benzene ring hydrogenation.Considering hydrogen consumption and lignin properties,the preference is directed towards generating aromatic hydrocarbons rather than saturated components.Thus,the goal is to selectively remove oxygen-containing functional groups while preserving the benzene ring structure.Studies on LDOs conversion have indicated that the design of active components and optimization of reaction conditions play pivotal roles in achieving selective deoxygenation,but a summary of the correlation between these factors and the reaction mechanism is lacking.This review addresses this gap in knowledge by firstly summarizing the various reaction pathways for HDO of LDOs.It explores the impact of catalyst design strategies,including morphology modulation,elemental doping,and surface modification,on the adsorption-desorption dynamics between reactants and catalysts.Secondly,we delve into the application of advanced techniques such as spectroscopic techniques and computational modeling,aiding in uncovering the true active sites in HDO reactions and understanding the interaction of reactive reactants with catalyst surface-interfaces.Additionally,fundamental insights into selective deoxygenation obtained through these techniques are highlighted.Finally,we outline the challenges that lie ahead in the design of highly active and selective HDO catalysts.These challenges include the development of detection tools for reactive species with high activity at low concentrations,the study of reaction medium-catalyst interactions,and the development of theoretical models that more closely approximate real reaction situations.Addressing these challenges will pave the way for the development of efficient and selective HDO catalysts,thus advancing the field of renewable LDOs conversion.
基金supported by the U.S.National Science Foundation (2208972,2120559,and 2323117)
文摘Rechargeable battery cycling performance and related safety have been persistent concerns.It is crucial to decipher the capacity fading induced by electrode material failure via a range of techniques.Among these,synchrotron-based X-ray techniques with high flux and brightness play a key role in understanding degradation mechanisms.In this comprehensive review,we summarize recent advancements in degra-dation modes and mechanisms that were revealed by synchrotron X-ray methodologies.Subsequently,an overview of X-ray absorption spectroscopy and X-ray scattering techniques is introduced for charac-terizing failure phenomena at local coordination atomic environment and long-range order crystal struc-ture scale,respectively.At last,we envision the future of exploring material failure mechanism.
基金financial support from the National Natural Science Foundation of China(Nos.62104017 and 52072204)Beijing Institute of Technology Research Fund Program for Young Scholars.
文摘Manipulating the expression of synaptic plasticity of neuromorphic devices provides fascinating opportunities to develop hardware platforms for artifi-cial intelligence.However,great efforts have been devoted to exploring biomimetic mechanisms of plasticity simulation in the last few years.Recent progress in various plasticity modulation techniques has pushed the research of synaptic electronics from static plasticity simulation to dynamic plasticity modulation,improving the accuracy of neuromorphic computing and providing strategies for implementing neuromorphic sensing functions.Herein,several fascinating strategies for synap-tic plasticity modulation through chemical techniques,device structure design,and physical signal sensing are reviewed.For chemical techniques,the underly-ing mechanisms for the modification of functional materials were clarified and its effect on the expression of synaptic plasticity was also highlighted.Based on device structure design,the reconfigurable operation of neuromorphic devices was well demonstrated to achieve programmable neuromorphic functions.Besides,integrating the sensory units with neuromorphic processing circuits paved a new way to achieve human-like intelligent perception under the modulation of physical signals such as light,strain,and temperature.Finally,considering that the relevant technology is still in the basic exploration stage,some prospects or development suggestions are put forward to promote the development of neuromorphic devices.
基金financially supported by the National Natural Science Foundation of China (No. 42272156)research on efficient exploration and development technology for tight stone gas of China United Coalbed Methane Corporation (No. ZZGSECCYWG 2021-322)。
文摘In this study, an integrated approach for diagenetic facies classification, reservoir quality analysis and quantitative wireline log prediction of tight gas sandstones(TGSs) is introduced utilizing a combination of fit-for-purpose complementary testing and machine learning techniques. The integrated approach is specialized for the middle Permian Shihezi Formation TGSs in the northeastern Ordos Basin, where operators often face significant drilling uncertainty and increased exploration risks due to low porosities and micro-Darcy range permeabilities. In this study, detrital compositions and diagenetic minerals and their pore type assemblages were analyzed using optical light microscopy, cathodoluminescence, standard scanning electron microscopy, and X-ray diffraction. Different types of diagenetic facies were delineated on this basis to capture the characteristic rock properties of the TGSs in the target formation.A combination of He porosity and permeability measurements, mercury intrusion capillary pressure and nuclear magnetic resonance data was used to analyze the mechanism of heterogeneous TGS reservoirs.We found that the type, size and proportion of pores considerably varied between diagenetic facies due to differences in the initial depositional attributes and subsequent diagenetic alterations;these differences affected the size, distribution and connectivity of the pore network and varied the reservoir quality. Five types of diagenetic facies were classified:(i) grain-coating facies, which have minimal ductile grains, chlorite coatings that inhibit quartz overgrowths, large intergranular pores that dominate the pore network, the best pore structure and the greatest reservoir quality;(ii) quartz-cemented facies,which exhibit strong quartz overgrowths, intergranular porosity and a pore size decrease, resulting in the deterioration of the pore structure and reservoir quality;(iii) mixed-cemented facies, in which the cementation of various authigenic minerals increases the micropores, resulting in a poor pore structure and reservoir quality;(iv) carbonate-cemented facies and(v) tightly compacted facies, in which the intergranular pores are filled with carbonate cement and ductile grains;thus, the pore network mainly consists of micropores with small pore throat sizes, and the pore structure and reservoir quality are the worst. The grain-coating facies with the best reservoir properties are more likely to have high gas productivity and are the primary targets for exploration and development. The diagenetic facies were then translated into wireline log expressions(conventional and NMR logging). Finally, a wireline log quantitative prediction model of TGSs using convolutional neural network machine learning algorithms was established to successfully classify the different diagenetic facies.
基金financially supported by National Research Foundation(NRF)grants(RS-2023-00266110,NRF-2020R1A5A1019649,NRF-2022M3C1A3081312,and NRF-2023M3K5A109482011)funded by the Ministry of Science and ICT(MSIT)of the Korean governmentI.Kim ac-knowledges the NRF Sejong Science Fellowship(NRF-2021R1C1C2004291)funded by the MSIT of the Korean government.
文摘Advanced imaging techniques have been widely used in various biological studies.Currently,numerous imaging modalities are utilized in biological applications,including medical imaging,diagnosis,biometrics,and fundamental biological research.Consequently,the demand for faster,clearer,and more accurate imaging techniques to support sophisticated biological studies has increased.However,there is a limitation in enhancing performance of imaging devices owing to the system complexity associated with bulky conventional optical elements.To address this issue,metasurfaces,which are flat and compact optical elements,have been considered potential candidates for biological imaging.Here,we comprehensively discuss the metasurface empowered various imaging applications in biology,including their working principles and design strategies.Furthermore,we compared conventional imaging modalities with the metasurface-based imaging system.Finally,we discuss the current challenges and offer future perspectives on metasurfaces.
基金Supported by the National Natural Science Foundation of China No.10572041 and No.50779008
文摘This paper presents the survey and assessment of the estimation techniques on hydrodynamic impact. The description and definition of hydrodynamic impact are presented, and the categorization of prediction techniques and the difficulties are discussed. Analysis theories and numerical simulation techniques are reviewed and the characteristics of those theories and approaches are analyzed. The efforts are made to pinpoint the advantages and disadvantages. Recommendations for further research and development are made.
文摘Although the genetic algorithm (GA) has very powerful robustness and fitness, it needs a large size of population and a large number of iterations to reach the optimum result. Especially when GA is used in complex structural optimization problems, if the structural reanalysis technique is not adopted, the more the number of finite element analysis (FEA) is, the more the consuming time is. In the conventional structural optimization the number of FEA can be reduced by the structural reanalysis technique based on the approximation techniques and sensitivity analysis. With these techniques, this paper provides a new approximation model-segment approximation model, adopted for the GA application. This segment approximation model can decrease the number of FEA and increase the convergence rate of GA. So it can apparently decrease the computation time of GA. Two examples demonstrate the availability of the new segment approximation model.
文摘The literature in 20th century is mainly characterized by irrationalism presented in modernism. Under the background, this paper aims to explore how Eliot attempts to use modern art techniques in The Waste Land to reveal a real life to readers.
文摘Most overseas tourists get the first impression of the place they will visit from tourist materials.Therefore,good translations of tourist materials become one of the key factors which attract overseas tourists.The translating techniques,such as Transcription,Addition,Omission,Rewriting,can help translators produce good translations.
文摘This paper presents four teaching techniques of activating the textbook for intensive reading which include:injecting contemporary elements into the text,relating the text to students' life,questioning about the text challengingly and ingeniously,and spicing up the text.
文摘Wuthering Heights has been one of the most famous novels in English literature. Emily's writing skills are worth the exploration. She can successfully handle the events out of chronological order; she can master the multiple narrator technique; she can create such repetitions of plots and she can design many meaningful symbols. No wonder why Wuthering Heights is in the a high position in the world literature.
文摘The onshore oil and gas exploration has stepped into a new stage in China, with equal attention paid to both stratigraphic and subtle reservoirs and structural reservoirs. In the past few years, the increases in oil reserves in most basins were found mainly in the stratigraphic and subtle reservoirs. Latest resource evaluation shows that the onshore stratigraphic and subtle reservoirs in China account for 42% of the total remaining resource, the highest in the four major exploration regions. Therefore, these reservoirs will be the most practical, potential and prevalent fields for long-lasting oil and gas exploration in onshore China. Among PetroChina's annual oil geologic reserves of 4.3 × 108t^4.6× 108t, the stratigraphic and subtle reservoirs account for more than 50%. In such basins as Songliao, Ordos, Bohai Bay, Junggar, Tarim, Sichuan and Erlian basins, stratigraphic and subtle reservoirs with geologic reserves ranging from 5×107t to 3×108t were discovered, including Ansai, Jing'an, Daqingzijing, Liuxi, well-21 area in Shinan, and Hadexun. Stratigraphic and subtle reservoirs in the four types of inland basins differ from each other in the formation conditions and the distribution patterns. While continental basins are controlled by unconformity surface, maximum flooding surface and fracture surface, the Paleozoic marine basins are influenced by paleouplift, unconformity surface, and fluctuation of the sea level. Through exploration practices and research, PetroChina has formed its own technique series focused on 3-D seismics and sequence stratigraphy.
文摘The Ordos basin is a stable craton whose late Paleozoic undergoes two sedimentary stages: from the middle- late Carboniferous offshore plain to the Permian continental river and lake delta. Sandstones in delta plain channels, delta-front river mouth bars and tidal channels are well developed. The sandstones are distributed on or between the genetic source rocks, forming good gas source conditions with widespread subtle lithologic gas pools of low porosity, low permeability, low pressure and low abundance. In recent years, a series of experiments has been done, aimed at overcoming difficulties in the exploration of lithologic gas pools. A set of exploration techniques, focusing on geological appraisal, seismic exploration, accurate logging evaluation and interpretation, well testing fracturing, has been developed to guide the exploration into the upper Paleozoic in the basin, leading to the discoveries of four large gas fields: Sulige, Yulin, Wushenqi and Mizhi.
基金Project supported by the National Key R&D Program of China(Grant No.2016YFA0401503)the National Materials Genome Project of China(Grant No.2016YFB0100106)the National Natural Science Foundation of China(Grant No.11675255)
文摘During the past decades,Li-ion batteries have been one of the most important energy storage devices.Large-scale energy storage requires Li-ion batteries which possess high energy density,low cost,and high safety.Other than advanced battery materials,in-depth understanding of the intrinsic mechanism correlated with cell reaction is also essential for the development of high-performance Li-ion battery.Advanced characterization techniques,especially neutron-based techniques,have greatly promoted Li-ion battery researches.In this review,the characteristics or capabilities of various neutron-based characterization techniques,including elastic neutron scattering,quasi-elastic neutron scattering,neutron imaging,and inelastic neutron scattering,for the related Li-ion-battery researches are summarized.The design of in-situ/operando environment is also discussed.The comprehensive survey on neutron-based characterizations for mechanism understanding will provide guidance for the further study of high-performance Li-ion batteries.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20170630)the National Natural Science Foundation of China(51802149 and U1801251)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Nanjing University Technology Innovation Fund Project。
文摘Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applications and novel devices constructed in recent years are necessary to be reviewed for inspiring subsequent studies.Hence,we summarize the progress of in-situ/operando techniques employed in rechargeable batteries.The members of this large family are divided into three sections for introduction,including bulk material,electrolyte/electrode interface and gas evolution.In each part,various energy-storage systems are mentioned and the related experimental details as well as data analysis are discussed.The simultaneous strategies of various in-situ methods are highlighted as well.Finally,current challenges and potential solutions are concluded towards the rising influence and enlarged appliance of in-situ/operando techniques in the battery research.
基金the National Natural Science Foundation of China (Grant nos.21233004,21303147 and 21473148,etc.)the National Key Research and Development Program (Grant no.2016YFB0901500)
文摘The increased use of rechargeable batteries in portable electronic devices and the continuous develop-ment of novel applications （e.g. transportation and large scale energy storage）, have raised a strong de-mand for high performance batteries with increased energy density, cycle and calendar life, safety andlower costs. This triggers significant efforts to reveal the fundamental mechanism determining batteryperformance with the use of advanced analytical techniques. However, the inherently complex character-istics of battery systems make the mechanism analysis sophisticated and difficult. Synchrotron radiationis an advanced collimated light source with high intensity and tunable energies. It has particular ad-vantages in electronic structure and geometric structure （both the short-range and long-range structure）analysis of materials on different length and time scales. In the past decades, synchrotron X-ray tech-niques have been widely used to understand the fundamental mechanism and guide the technologicaloptimization of batteries. In particular, in situ and operando techniques with high spatial and temporalresolution, enable the nondestructive, real time dynamic investigation of the electrochemical reaction,and lead to significant deep insights into the battery operation mechanism. This review gives a brief introduction of the application of synchrotron X-ray techniques to the inves-tigation of battery systems. The five widely implicated techniques, including X-ray diffraction （XRD）, PairDistribution Function （PDF）, Hard and Soft X-ray absorption spectroscopy （XAS） and X-ray photoelectronspectroscopy （XPS） will be reviewed, with the emphasis on their in situ studies of battery systems during cycling.
基金Project supported by the Joint Funds of the National Natural Science Foundation of China(Grant No.U1601213)the National Natural Science Foundation of China(Grant Nos.51601005 and 61704006)+1 种基金the Beijing Natural Science Foundation(Grant No.2182032)the Fundamental Research Funds for the Central Universities
文摘Thermoelectric materials have aroused widespread concern due to their unique ability to directly convert heat to electricity without any moving parts or noxious emissions.Taking advantages of two-dimensional structures of thermoelectric films,the potential applications of thermoelectric materials are diversified,particularly in microdevices.Well-controlled nanostructures in thermoelectric films are effective to optimize the electrical and thermal transport,which can significantly improve the performance of thermoelectric materials.In this paper,various physical and chemical approaches to fabricate thermoelectric films,including inorganic,organic,and inorganic–organic composites,are summarized,where more attentions are paid on the inorganic thermoelectric films for their excellent thermoelectric responses.Additionally,strategies for enhancing the performance of thermoelectric films are also discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11775167,11575138,and 11835006)
文摘In this paper we investigate two techniques for single event effect(SEE) mitigation by using back junction and p^+buffer layer in non-deep trench isolation(DTI) domestic silicon–germanium heterojunction bipolar transistors(SiGe HBTs)based on technology computer aided design(TCAD) simulation. The effectiveness of the two mitigation techniques and the influence of various structure parameters are investigated. Simulation results indicate that the two techniques are more effective in reducing collector charge collection induced by heavy ions striking at positions outside the collector–substrate(C–S) junction where charge collection is dominated by diffusion. By properly adjusting the parameters, charge collection of events outside the C–S junction can be reduced by more than an order of magnitude, while charge collection of events in the device center is halved without affecting the direct current(DC) and alternating current(AC) characteristics of the SiGe HBTs.
