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Design Principles and Mechanistic Understandings of Non-Noble-Metal Bifunctional Electrocatalysts for Zinc-Air Batteries 被引量:1
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作者 Yunnan Gao Ling Liu +10 位作者 Yi Jiang Dexin Yu Xiaomei Zheng Jiayi Wang Jingwei Liu Dan Luo Yongguang Zhang Zhenjia Shi Xin Wang Ya‑Ping Deng Zhongwei Chen 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第9期13-48,共36页
Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-... Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-metal catalysts hinder the practical applications of ZABs.Therefore,feasible and advanced non-noble-metal elec-trocatalysts for air cathodes need to be identified to promote the oxygen catalytic reaction.In this review,we initially introduced the advancement of ZABs in the past two decades and provided an overview of key developments in this field.Then,we discussed the work-ing mechanism and the design of bifunctional electrocatalysts from the perspective of morphology design,crystal structure tuning,interface strategy,and atomic engineering.We also included theoretical studies,machine learning,and advanced characterization technologies to provide a comprehensive understanding of the structure-performance relationship of electrocatalysts and the reaction pathways of the oxygen redox reactions.Finally,we discussed the challenges and prospects related to designing advanced non-noble-metal bifunctional electrocatalysts for ZABs. 展开更多
关键词 Zinc-air batteries Bifunctional electrocatalysts Design principles Mechanistic understandings
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Anisotropic etching mechanisms of 4H-SiC:Experimental and first-principles insights
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作者 Guang Yang Lingbo Xu +3 位作者 Can Cui Xiaodong Pi Deren Yang Rong Wang 《Journal of Semiconductors》 EI CAS CSCD 2024年第1期42-47,共6页
Molten-alkali etching has been widely used to reveal dislocations in 4H silicon carbide(4H-SiC),which has promoted the identification and statistics of dislocation density in 4H-SiC single crystals.However,the etching... Molten-alkali etching has been widely used to reveal dislocations in 4H silicon carbide(4H-SiC),which has promoted the identification and statistics of dislocation density in 4H-SiC single crystals.However,the etching mechanism of 4H-SiC is limited misunderstood.In this letter,we reveal the anisotropic etching mechanism of the Si face and C face of 4H-SiC by combining molten-KOH etching,X-ray photoelectron spectroscopy(XPS)and first-principles investigations.The activation energies for the molten-KOH etching of the C face and Si face of 4H-SiC are calculated to be 25.09 and 35.75 kcal/mol,respectively.The molten-KOH etching rate of the C face is higher than the Si face.Combining XPS analysis and first-principles calculations,we find that the molten-KOH etching of 4H-SiC is proceeded by the cycling of the oxidation of 4H-SiC by the dissolved oxygen and the removal of oxides by molten KOH.The faster etching rate of the C face is caused by the fact that the oxides on the C face are unstable,and easier to be removed with molten alkali,rather than the C face being easier to be oxidized. 展开更多
关键词 principles ALKALI ETCHING
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Scientific principles for accelerating the Sustainable Development Goals
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作者 Bojie Fu Xutong Wu +1 位作者 Shuai Wang Wenwu Zhao 《Geography and Sustainability》 CSCD 2024年第2期157-159,共3页
The Sustainable Development Goals(SDGs)are significantly off-course as we reach the midpoint of their 2030 deadline.From a scientific perspective,the critical challenge in achieving the SDGs lies in the need for more ... The Sustainable Development Goals(SDGs)are significantly off-course as we reach the midpoint of their 2030 deadline.From a scientific perspective,the critical challenge in achieving the SDGs lies in the need for more scientific principles to understand the complex socio-ecological systems(SES)and their interactions influencing the 17 SDGs.Here,we propose a scientific framework to clarify the common scientific principles and the rational treatment of diversity under these principles.The framework’s core is revealing the complex mechanisms underlying the achievement of each Sustainable Development Goal(SDG)and SDG interactions.Building upon the identified mechanisms,complex SES models can be established,and the implementation of SDGs can be formulated as a multi-objective optimization problem,seeking a compromise in competition between essential costs and desired benefits.Our framework can assist countries,and even the world in accelerating progress towards the SDGs. 展开更多
关键词 principles SUSTAINABLE RATIONAL
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International law obligations for the disposal of Fukushima nuclear-contaminated water under the principles of nuclear safety
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作者 Wei Gong 《Chinese Journal of Population,Resources and Environment》 2024年第1期10-19,共10页
The disposal of contaminated water from Japan’s Fukushima nuclear power plant is a significant international nuclear safety issue with considerable cross-border implications.This matter requires compliance not only w... The disposal of contaminated water from Japan’s Fukushima nuclear power plant is a significant international nuclear safety issue with considerable cross-border implications.This matter requires compliance not only with the law of the sea but also with the principles of nuclear safety under international law.These principles serve as the overarching tenet of international and China’s domestic nuclear laws,applicable to nuclear facilities and activities.The principle of safety in nuclear activities is fully recognized in international and domestic laws,carrying broad legal binding force.Japan’s discharge of nuclear-contaminated water into the sea violates its obligations under the principle of safety in nuclear activities,including commitments to optimum protection,as low as reasonably practicable,and prevention.The Japanese government and the International Atomic Energy Agency(IAEA)have breached the obligation of optimum protection by restricting the scope of assessments,substituting core concepts,and shielding dissenting views.In the absence of clear radiation standards,they have acted unilaterally without fulfilling the obligation as low as reasonably practicable principle.The discharge of Fukushima nuclear-contaminated water poses an imminent and unpredictable risk to all countries worldwide,including Japanese residents.Japan and the IAEA should fulfill their obligations under international law regarding disposal,adhering to the principles of nuclear safety,including optimum protection,the obligation as low as reasonably practicable,and prevention through multilateral cooperation.Specifically,the obligation to provide optimum protection should be implemented by re-evaluating the most reliable disposal technologies and methods currently available and comprehensively assessing various options.The standard of the obligation as low as reasonably practicable requires that the minimization of negative impacts on human health,livelihoods,and the environment should not be subordinated to considerations of cutting costs and expenses.Multilateral cooperation should be promoted through the establishment of sound multilateral long-term monitoring mechanisms for the discharge of nuclear-contaminated water,notification and consultation obligations,and periodic assessments.These obligations under international law were fulfilled after the accidents at the Three Mile Island and Chernobyl nuclear power plants.The implications of the principles of nuclear safety align with the concept of building a community of shared future for nuclear safety advocated by China.In cases of violations of international law regarding the disposal of nuclear-contaminated water that jeopardize the concept of a community of a shared future for nuclear safety,China can also rely on its own strength to promote the implementation of due obligations through self-help. 展开更多
关键词 principles of nuclear safety Disposal of nuclear-contaminated water Optimum protection Prevention As low as reasonably achievable
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Fundamental Principles behind Climate Change
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作者 Haiyan DAI 《Meteorological and Environmental Research》 2024年第4期21-23,共3页
The attribution of climate change is complex,and the current mainstream view is more inclined towards human activities and carbon dioxide emissions from fossil fuels.Any complex problem is composed of basic principles... The attribution of climate change is complex,and the current mainstream view is more inclined towards human activities and carbon dioxide emissions from fossil fuels.Any complex problem is composed of basic principles.This article elaborates on the basic logic behind climate change(a global hot topic)through basic principles such as reaction types,carbon thermal properties of biomass energy,greenhouse gas attribution,ecological basic theory,and energy cycle. 展开更多
关键词 Climate change Feedback mechanisms Fundamental principles DISASTERS
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Four Dimensions of Integrating Chinese Culture Into College English Teaching From the Perspective of Tyler’s Basic Principles
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作者 CHEN Lijuan 《Sino-US English Teaching》 2024年第5期232-237,共6页
Integrating Chinese culture into college English can not only enhance students’humanities literacy and cultivate their cultural confidence,but also facilitate the inheritance and international dissemination of Chines... Integrating Chinese culture into college English can not only enhance students’humanities literacy and cultivate their cultural confidence,but also facilitate the inheritance and international dissemination of Chinese culture.Taking Tyler’s curriculum framework as the starting point,this paper analyzes some factors that affect the integration of Chinese culture into the college English teaching and proposes some strategies for the integration of Chinese culture into college English teaching by innovating teaching objectives,enriching teaching contents,transforming modes of course delivery,and reconstructing the assessment system. 展开更多
关键词 Tyler’s basic principles Chinese culture college English
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Principles of Shiology——Revealing the Basic Rules of Human Shiance
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作者 Liu Guangwei 《Journal of Northeast Agricultural University(English Edition)》 CAS 2024年第1期83-96,共14页
The objective principles of shiology are mainly reflected in three fields as food acquisition, eaters' health and shiance order. Most of the objective principles in the field of food acquisition have been revealed... The objective principles of shiology are mainly reflected in three fields as food acquisition, eaters' health and shiance order. Most of the objective principles in the field of food acquisition have been revealed by agronomy and foodstuff science. This research mainly focuses on 10 principles in the field of eaters' health and shiance order and in addition, there are also five lemmas that extend from the above principles. The 10 principles are the core theory of the shiology knowledge system, which play an important role in the objective principles revealed by human beings and constitute one of the basic principles of human civilization. Compared with the scientific principles of mathematics, physics, chemistry and economics, the principles of shiology have three characteristics as popularity, practicability and survivability. The principles of shiology in the field of eaters' health are all around us, and everyone can understand and master them. Using the principles of shiology can improve the healthy life span of 8 billion people. The principles of shiology in the field of shiance order is an important tool of social governance, which can reduce human social conflicts, reduce social involution, improve overall efficiency of social operation, and maintain the sustainable development of human beings. 展开更多
关键词 principle of shiology RULE shiance eater eating matter eatology
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Research on the Course of Principles of Concrete Structure Design
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作者 Yuhuan Shi Jinping Hu +2 位作者 Xue Lin Zhinan Jiang Jialian Qi 《Journal of Contemporary Educational Research》 2024年第2期80-84,共5页
Nowadays,education and teaching have become a hot topic,and teaching in colleges and universities is facing a brand-new development direction.Principles of Concrete Structure Design,as one of the main courses,transmit... Nowadays,education and teaching have become a hot topic,and teaching in colleges and universities is facing a brand-new development direction.Principles of Concrete Structure Design,as one of the main courses,transmits professional knowledge for students,enhances the students’professional ability,and further carries out in-depth research on the course to bring a better teaching effect for students.The article mainly focuses on the research of the principles of concrete structure design course,conducts an analysis of the teaching characteristics of the principles of concrete structure design course,and reasonably sets the teaching content from the optimization of the course teaching objectives;innovative course teaching methods can deepen the effect of knowledge understanding;reform of experimental practice teaching can lay down the effect of the internalization of knowledge,etc.The in-depth description and discussion of the relevant aspects of the research aim to provide guidelines for related research. 展开更多
关键词 Concrete structure design principle Course characteristics Teaching innovation Course research
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Research on Teaching Methods of Flight Control Principles
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作者 Dongying Li 《Journal of Electronic Research and Application》 2024年第3期155-160,共6页
With the rapid development of China’s civil aviation industry,the teaching method of operating knowledge of flight principles has changed greatly,which creates a good implementation environment to improve the safety ... With the rapid development of China’s civil aviation industry,the teaching method of operating knowledge of flight principles has changed greatly,which creates a good implementation environment to improve the safety of civil aviation in our country.At present,the main training content of air route transport pilots in China is basic aviation theory,initial flight training,airline modification,etc.The principles of flight control are an important part of basic aviation theoretical knowledge training,which will involve a large number of flight technology training content,instructors will also be based on the pilot type.Teaching flight control theory and practical knowledge requires relatively high theoretical learning ability of students,and the learning effect of this part of theoretical knowledge will directly affect the quality of subsequent learning,but also directly affect the effectiveness of flight training.This paper focuses on the analysis of the basic concepts of flight control,studies the existing problems in the teaching of flight control principles,summarizes the teaching measures of flight control principles,aiming to provide a reference to teaching personnel. 展开更多
关键词 Flight control principle knowledge Virtual simulation Teaching method
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The Principles of Insulin Management of Type 2 Diabetes Mellitus
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作者 Leslie Bahn Kawa Henry Alexander 《Journal of Diabetes Mellitus》 2023年第4期284-299,共16页
Insulin therapy is an integral part of the pharmacological management of Type 2 diabetes mellitus. Guidelines recommended insulin therapy for those patients with suboptimal glycaemic control despite optimal medical tr... Insulin therapy is an integral part of the pharmacological management of Type 2 diabetes mellitus. Guidelines recommended insulin therapy for those patients with suboptimal glycaemic control despite optimal medical treatments. Studies show that insulin therapy with the human and regular insulins improve glycaemic control, reduce the chronic complications, and inevitably improve patient’s quality of life. The new analogue insulin has a better safety profile and efficacies, and has been shown to achieve better outcomes and patient’s acceptability compared with the human and regular insulins. The diabetic guidelines also recommend the intensity of insulin therapy in a personalised glycaemic control strategy based on the patient’s profiles and their preferences. However, the guidelines do not recommend any standardised approach to the principles of insulin initiation, titration, and monitoring. This review summarises the essential principles of insulin initiation, titration, and monitoring in Type 2 diabetes mellitus. 展开更多
关键词 INSULIN Type 2 Diabetes principles of Insulin Therapy
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On the “Online and Offline Blended Teaching” Mode for Ideological and Political Theory Courses in Universities—A Case of “Introduction to Basic Principles of Marxism”
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作者 Jinfeng Wu 《Open Journal of Applied Sciences》 2023年第9期1479-1488,共10页
With the deepening development of educational informatization, online and offline blended teaching, as a new teaching mode, is increasingly receiving widespread attention from educators [1]. At present, the reform of ... With the deepening development of educational informatization, online and offline blended teaching, as a new teaching mode, is increasingly receiving widespread attention from educators [1]. At present, the reform of the “online and offline blended teaching” of ideological and political education courses directly affects the quality of talent cultivation in universities. The article takes the course “Introduction to Basic Principles of Marxism” as an example to explore the reform mode of “online and offline blended teaching” in ideological and political theory courses in universities from the aspects of reasonable allocation of class hours, design of online teaching activities, how to deepen classroom teaching offline, and diversified assessment modes. Furthermore, the article summarizes the experience of mode reform and promotes the deep development of the people-oriented education concept in ideological and political courses in universities, so as to achieve the ultimate goal of moral education in ideological and political education in universities. 展开更多
关键词 Ideological and Political Theory Courses in Universities Online and Offline Blended Teaching Introduction to Basic principles of Marxism
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Lithium nitrate regulated carbonate electrolytes for practical Li-metal batteries: Mechanisms, principles and strategies 被引量:2
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作者 Kun Wang Wenbing Ni +9 位作者 Liguang Wang Lu Gan Jing Zhao Zhengwei Wan Wei Jiang Waqar Ahmad Miaomiao Tian Min Ling Jun Chen Chengdu Liang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第2期581-600,I0015,共21页
Li-metal batteries(LMBs)regain research prominence owing to the ever-increasing high-energy requirements.Commercially available carbonate electrolytes exhibit unfavourable parasitic reactions with Limetal anode(LMA),l... Li-metal batteries(LMBs)regain research prominence owing to the ever-increasing high-energy requirements.Commercially available carbonate electrolytes exhibit unfavourable parasitic reactions with Limetal anode(LMA),leading to the formation of unstable solid electrolyte interphase(SEI)and the breed of Li dendrites/dead Li.Significantly,lithium nitrate(LiNO_(3)),an excellent film-forming additive,proves crucial to construct a robust Li_(3)N/Li_(2)O/Li_(x)NO_(y)-rich SEI after combining with ether-based electrolytes.Thus,the given challenge leads to natural ideas which suggest the incorporation of LiNO_(3) into commercial carbonate for practical LMBs.Regrettably,LiNO_(3) demonstrates limited solubility(~800 ppm)in commercial carbonate electrolytes.Thence,developing stable SEI and dendrite-free LMA with the incorporation of LiNO_(3) into carbonate electrolytes is an efficacious strategy to realize robust LMBs via a scalable and cost-effective route.Therefore,this review unravels the grievances between LMA,LiNO_(3)and carbonate electrolytes,and enables a comprehensive analysis of LMA stabilizing mechanism with LiNO_(3),dissolution principle of LiNO_(3) in carbonate electrolytes,and LiNO_(3) introduction strategies.This review converges attention on a point that the LiNO_(3)-introduction into commercial carbonate electrolytes is an imperious choice to realize practical LMBs with commercial 4 V layered cathode. 展开更多
关键词 Li-metal battery Carbonate electrolyte Lithium nitrate Stabilization mechanism Dissolution principle Introduction strategy
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How to improve machine learning models for lithofacies identification by practical and novel ensemble strategy and principles
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作者 Shao-Qun Dong Yan-Ming Sun +4 位作者 Tao Xu Lian-Bo Zeng Xiang-Yi Du Xu Yang Yu Liang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第2期733-752,共20页
Typically, relationship between well logs and lithofacies is complex, which leads to low accuracy of lithofacies identification. Machine learning (ML) methods are often applied to identify lithofacies using logs label... Typically, relationship between well logs and lithofacies is complex, which leads to low accuracy of lithofacies identification. Machine learning (ML) methods are often applied to identify lithofacies using logs labelled by rock cores. However, these methods have accuracy limits to some extent. To further improve their accuracies, practical and novel ensemble learning strategy and principles are proposed in this work, which allows geologists not familiar with ML to establish a good ML lithofacies identification model and help geologists familiar with ML further improve accuracy of lithofacies identification. The ensemble learning strategy combines ML methods as sub-classifiers to generate a comprehensive lithofacies identification model, which aims to reduce the variance errors in prediction. Each sub-classifier is trained by randomly sampled labelled data with random features. The novelty of this work lies in the ensemble principles making sub-classifiers just overfitting by algorithm parameter setting and sub-dataset sampling. The principles can help reduce the bias errors in the prediction. Two issues are discussed, videlicet (1) whether only a relatively simple single-classifier method can be as sub-classifiers and how to select proper ML methods as sub-classifiers;(2) whether different kinds of ML methods can be combined as sub-classifiers. If yes, how to determine a proper combination. In order to test the effectiveness of the ensemble strategy and principles for lithofacies identification, different kinds of machine learning algorithms are selected as sub-classifiers, including regular classifiers (LDA, NB, KNN, ID3 tree and CART), kernel method (SVM), and ensemble learning algorithms (RF, AdaBoost, XGBoost and LightGBM). In this work, the experiments used a published dataset of lithofacies from Daniudi gas field (DGF) in Ordes Basin, China. Based on a series of comparisons between ML algorithms and their corresponding ensemble models using the ensemble strategy and principles, conclusions are drawn: (1) not only decision tree but also other single-classifiers and ensemble-learning-classifiers can be used as sub-classifiers of homogeneous ensemble learning and the ensemble can improve the accuracy of the original classifiers;(2) the ensemble principles for the introduced homogeneous and heterogeneous ensemble strategy are effective in promoting ML in lithofacies identification;(3) in practice, heterogeneous ensemble is more suitable for building a more powerful lithofacies identification model, though it is complex. 展开更多
关键词 Lithofacies identification Machine learning Ensemble learning strategy Ensemble principle Homogeneous ensemble Heterogeneous ensemble
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First principles calculation of intermetallic compounds in FeTiCoNiVCrMnCuAl system high entropy alloy 被引量:10
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作者 农智升 朱景川 +1 位作者 于海玲 来忠红 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第6期1437-1444,共8页
The structural, electronic and elastic properties of common intermetallic compounds in FeTiCoNiVCrMnCuAI system high entropy alloy were investigated by the first principles calculation. The calculation results of form... The structural, electronic and elastic properties of common intermetallic compounds in FeTiCoNiVCrMnCuAI system high entropy alloy were investigated by the first principles calculation. The calculation results of formation enthalpy and cohesive energy show that FeTi, Fe2Ti, AlCrFe2, Co2Ti, AlMn2V and Mn2Ti phases may form in the formation process of the alloy. Further studies show that FeTi, FezTi, AlCrFe2, Co2Ti and AlMn2V phases with higher shear modulus and elastic modulus would be excellent strengthening phases in high entropy alloy and would improve the hardness of the alloy. In addition, the partial density of states was investigated for revealing the bonding mode, and the analyses on the strength of p-d hybridization also reveal the underlying mechanism for the elastic properties of these compounds. 展开更多
关键词 FeTiCoNiVCrMnCuA1 system high entropy alloy first principles calculation phase stability
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Probability Distribution of SARS-Cov-2 (COVID) Infectivity Following Onset of Symptoms: Analysis from First Principles
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作者 Mark P. Silverman 《Open Journal of Statistics》 2023年第2期233-263,共31页
The phasing out of protective measures by governments and public health agencies, despite continued seriousness of the coronavirus pandemic, leaves individuals who are concerned for their health with two basic options... The phasing out of protective measures by governments and public health agencies, despite continued seriousness of the coronavirus pandemic, leaves individuals who are concerned for their health with two basic options over which they have control: 1) minimize risk of infection by being vaccinated and by wearing a face mask when appropriate, and 2) minimize risk of transmission upon infection by self-isolating. For the latter to be effective, it is essential to have an accurate sense of the probability of infectivity as a function of time following the onset of symptoms. Epidemiological considerations suggest that the period of infectivity follows a lognormal distribution. This proposition is tested empirically by construction of the lognormal probability density function and cumulative distribution function based on quantiles of infectivity reported by several independent investigations. A comprehensive examination of a prototypical ideal clinical study, based on general statistical principles (the Principle of Maximum Entropy and the Central Limit Theorem) reveals that the probability of infectivity is a lognormal random variable. Subsequent evolution of new variants may change the parameters of the distribution, which can be updated by the methods in this paper, but the form of the probability function is expected to remain lognormal as this is the most probable distribution consistent with mathematical requirements and available information. 展开更多
关键词 COVID SARS-Cov-2 Period of Infectivity Probability of Infectivity Viral Shedding Infectiousness Kaplan-Meier Curve Principle of Maximum Entro-py
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First principles calculation on ternary stannide phase narrow band gap semiconductor Na_2MgSn 被引量:1
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作者 王一夫 夏庆林 +1 位作者 潘留仙 余燕 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第6期1853-1858,共6页
The electronic structures,chemical bonding,elastic and optical properties of the ternary stannide phase Na2MgSn were investigated by using density-fimctional theory(DFT) within generalized gradient approximation(GG... The electronic structures,chemical bonding,elastic and optical properties of the ternary stannide phase Na2MgSn were investigated by using density-fimctional theory(DFT) within generalized gradient approximation(GGA).The calculated energy band structures show that Na2MgSn is an indirect semiconductor material with a narrow band gap 0.126 eV.The density of state(DOS)and the partial density of state(PDOS) calculations show that the DOS near the Fermi level is mainly from the Na 2p,Mg 3p and Sn5 p states.Population analysis suggests that there are strongly bonded Mg-Sn honeycomb layers in Na2MgSn.Basic physical properties,such as lattice constant,bulk modulus,shear modulus,elastic constants c(ij) were calculated.The elastic modulus E and Poisson ratio v were also predicted.The results show that Na2MgSn is mechanically stable soft material and behaves in a brittle manner.Detailed analysis of all optical functions reveals that Na2MgSn is a better dielectric material,and reflectivity spectra show that Na2MgSn promise as good coating materials in the energy regions 6.24-10.49 eV. 展开更多
关键词 stannide phase Na2MgSn first principles electronic structures chemical bonding elastic properties optical properties
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高等教育出版社最新引进的General Chemistry:Principles and Modern Applications 被引量:3
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作者 卞江 《大学化学》 CAS 2004年第2期63-64,共2页
关键词 书评 《普通化学原理与应用》 大学普通化学 教材 人性化组织结构 《General Chemistry: principles and MODERN Applications》 高等教育出版社
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First principles study of electronic structure, chemical bonding and elastic properties of BiOCuS
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作者 潘留仙 夏庆林 +2 位作者 叶绍龙 丁宁 刘自然 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1197-1202,共6页
The electronic structures, chemical bonding and elastic properties of the tetragonal phase BiOCuS were investigated by using density-functional theory (DFT) within generalized gradient approximation (GGA). The cal... The electronic structures, chemical bonding and elastic properties of the tetragonal phase BiOCuS were investigated by using density-functional theory (DFT) within generalized gradient approximation (GGA). The calculated energy band structures show that the tetragonal phase BiOCuS is an indirect semiconductor with the calculated band gap of about 0.503 eV. The density of states (DOS) and the partial density of states (PDOS) calculations show that the DOS near the Fermi level is mainly from the Cu-3d state. Population analysis suggests that the chemical bonding in BiOCuS has predominantly ionic character with mixed covalent-ionic character. Basic physical properties, such as lattice constant, bulk modulus, shear modulus, elastic constants, were calculated. The elastic modulus and Poisson ratio were also predicted. The results show that tetragonal phase BiOCuS is mechanically stable and behaves in a ductile manner. 展开更多
关键词 BiOCuS first principles electronic structures chemical bonding elastic properties
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First Principles Study of Electronic Structure and Half-metallicity ot Molecule-based Ferromagnet Cr[N(CN)2]2
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作者 黄海铭 罗时军 +1 位作者 刘国营 姚凯伦 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第2期189-193,I0004,共6页
The electronic structure and half-metallicity of molecule-based ferromagnet Cr[N(CN)2]2 have been investigated using first-principles with generalized gradient approximation. The total energy, spin-polarized electro... The electronic structure and half-metallicity of molecule-based ferromagnet Cr[N(CN)2]2 have been investigated using first-principles with generalized gradient approximation. The total energy, spin-polarized electronic band structure, density of states (DOSs) and spin magnetic moments were all calculated. The calculations reveal that the compound Cr[N(CN)2]2 is a really half-metallic ferromagnet with a integral magnetic moment of 2.0000 μB per molecule in the optimized lattice constant. Based on the spin distribution and the DOS, it is found that the total magnetic moment is mainly from the Cr2+ with relative small contribution from C and N atoms. The sensitivity of the half-metallicity to small change in lattice constant is also discussed. 展开更多
关键词 First principles Magnetic property Half-metallic property
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First principles calculation of electronic structure, chemical bonding and elastic properties of ultra-incompressible Re_2P
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作者 王一夫 夏庆林 余燕 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第11期3400-3404,共5页
The electronic structures, chemical bonding and elastic properties of the Co2P-type structure phase ultra-incompressible Re2P (orthorhombic phase) were investigated by density-functional theory (DFT) within genera... The electronic structures, chemical bonding and elastic properties of the Co2P-type structure phase ultra-incompressible Re2P (orthorhombic phase) were investigated by density-functional theory (DFT) within generalized gradient approximation (GGA). The calculated energy band structures show that the orthorhombic structure phase Re2P is metallic material. The density of state (DOS) and the partial density of state (PDOS) calculations show that the DOS near the Fermi level is mainly from the Re-5d state. Population analysis suggests that the chemical bonding in Re2P has predominantly covalent character with mixed covalent-ionic character. Basic physical properties, such as lattice constant, bulk modulus, shear modulus, and elastic constants Cij, were calculated. The elastic modulus and Poisson ratio were also predicted. The results show that the Co2P-type structure phase Re2P is mechanically stable and behaves in a brittle manner. 展开更多
关键词 Re2P first principles electronic structures chemical bonding elastic properties
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