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The Evolution of Theory of Mind in the Human Evolution 认领
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作者 Dingyu Chung 《行为与脑科学期刊(英文)》 2021年第1期10-26,共17页
Despite almost half a century of research for theory of mind, its evolutionary origin is largely unknown. This paper proposes that the evolutionary origin of theory of mind starts from the beginning of the human evolu... Despite almost half a century of research for theory of mind, its evolutionary origin is largely unknown. This paper proposes that the evolutionary origin of theory of mind starts from the beginning of the human evolution to form hominins through bipedalism and the mixed habitat. The feet of the early hominins were still adapted for grasping trees rather than walking for long distances and running fast on the ground. The early hominins lived in the mixed habitat of grassy woodland with patches of denser forest, and freshwater springs. The difficulty of walking in the mixed habitat leads to division of labor for the home specialist group (small children, old people, and mothers with small children, and pregnant women) in the safe forest area and the exploration specialist group (young people without the care of small children) in the dangerous open area. The different tasks, attitudes, and mentalities in different specialist groups produce theory of mind as the ability to attribute different mental states to different specialist groups. (Uniformity of mind instead of theory of mind is for generalists without division of labor). The early Homo species with the open habitat developed theory of mind for hunter specialist group and gatherer specialist group. The middle Homo species with complex stone tools developed theory of mind for the cooperative specialist groups in the large production of complex stone tools. The late Homo species with complex social interaction developed theory of mind for mind reading to enhance cooperation and to detect cheaters in complex social interaction. For religion, the unusually harsh Upper Paleolithic Period developed theory of mind for imaginary specialists in terms of supernatural power, guidance, and comfort. Therefore, the three general types of theory of mind are for specialists in division of labor, mind reading in complex social interaction, and imaginary specialists in imaginary division of labor under harsh conditions. Self-awareness in the mirror self-recognition test is al 展开更多
关键词 Theory of Mind Human Evolution Evolution of Theory of Mind RELIGION SELF-AWARENESS Mirror Self-Recognition Test
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Covariance Matrix Learning Differential Evolution Algorithm Based on Correlation 认领
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作者 Sainan Yuan Quanxi Feng 《智能科学国际期刊(英文)》 2021年第1期17-30,共14页
Differential evolution algorithm based on the covariance matrix learning can adjust the coordinate system according to the characteristics of the population, which make<span style="font-family:Verdana;"&g... Differential evolution algorithm based on the covariance matrix learning can adjust the coordinate system according to the characteristics of the population, which make<span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> the search move in a more favorable direction. In order to obtain more accurate information about the function shape, this paper propose</span><span style="font-family:Verdana;">s</span><span style="font-family:;" "=""> <span style="font-family:Verdana;">covariance</span><span style="font-family:Verdana;"> matrix learning differential evolution algorithm based on correlation (denoted as RCLDE)</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">to improve the search efficiency of the algorithm. First, a hybrid mutation strategy is designed to balance the diversity and convergence of the population;secondly, the covariance learning matrix is constructed by selecting the individual with the less correlation;then, a comprehensive learning mechanism is comprehensively designed by two covariance matrix learning mechanisms based on the principle of probability. Finally,</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">the algorithm is tested on the CEC2005, and the experimental results are compared with other effective differential evolution algorithms. The experimental results show that the algorithm proposed in this paper is </span><span style="font-family:Verdana;">an effective algorithm</span><span style="font-family:Verdana;">.</span></span> 展开更多
关键词 Differential Evolution Algorithm CORRELATION Covariance Matrix Parameter Self-Adaptive Technique
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The Genesis of Prime Numbers—Revealing the Underlying Periodicity of Prime Numbers 认领
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作者 Xin Wang 《理论数学进展(英文)》 2021年第1期12-18,共7页
Prime numbers are the integers that cannot be divided exactly by another integer other than one and itself. Prime numbers are notoriously disobedient to rules: they seem to be randomly distributed among natural number... Prime numbers are the integers that cannot be divided exactly by another integer other than one and itself. Prime numbers are notoriously disobedient to rules: they seem to be randomly distributed among natural numbers with no laws except that of chance. Questions about prime numbers have been perplexing mathematicians over centuries. How to efficiently predict greater prime numbers has been a great challenge for many. Most of the previous studies focus on how many prime numbers there are in certain ranges or patterns of the first or last digits of prime numbers. Honestly, although these patterns are true, they help little with accurately predicting new prime numbers, as a deviation at any digit is enough to annihilate the primality of a number. The author demonstrates the periodicity and inter-relationship underlying all prime numbers that makes the occurrence of all prime numbers predictable. This knowledge helps to fish all prime numbers within one net and will help to speed up the related research. 展开更多
关键词 Prime Number GENESIS PERIODICITY RULE Prediction Number Theory Evolution
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Scaling Behavior for the Susceptibility of the Vacuum 认领
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作者 Christopher Pilot 《天文学与天体物理学国际期刊(英文)》 2021年第1期11-36,共26页
Using the two-component superfluid model of Winterberg for space, two models for the susceptibility of the cosmic vacuum as a function of the cosmic scale parameter, a, are presented. We also consider the possibility ... Using the two-component superfluid model of Winterberg for space, two models for the susceptibility of the cosmic vacuum as a function of the cosmic scale parameter, a, are presented. We also consider the possibility that Newton’s constant can scale,<em> i.e.</em>, <span style="white-space:nowrap;"><em>G</em><sup>-1</sup>=<em>G</em><sup>-1</sup>(<em>a</em>)</span>, to form the most general scaling laws for polarization of the vacuum. The positive and negative values for the Planckion mass, which form the basis of the Winterberg model, are inextricably linked to the value of G, and as such, both G and Planck mass are intrinsic properties of the vacuum. Scaling laws for the non-local, smeared, cosmic susceptibility, <img src="Edit_bd58a08a-5d33-4e33-b5c0-62650c0b1918.bmp" alt="" />, the cosmic polarization, <img src="Edit_56bd1950-09ae-49fa-bd34-e4ff13b30c56.bmp" alt="" />, the cosmic macroscopic gravitational field, <img src="Edit_1e22ee4f-7755-4b29-8f8d-66f20f98aaa7.bmp" alt="" />, and the cosmic gravitational field mass density, <img src="Edit_aabb0cf4-080e-4452-ba73-8f3d50e95363.bmp" alt="" />, are worked out, with specific examples. At the end of recombination,<em> i.e.</em>, the era of last scattering, using the polarization to explain dark matter, and the gravitational field mass density to explain dark energy, we find that, <img src="Edit_b4b9804e-a8db-4c86-a1ad-1bc5f8ec72fa.bmp" alt="" />. While this is an unconventional assignment, differing from the ΛCDM model, we believe this is correct, as localized dark matter (LDM) contributions can be much higher in this epoch than cosmic smeared values for susceptibility. All density parameter assignments in Friedmanns’ equation are cosmic averages, valid for distance scales in excess of 100 Mpc in the current epoch. We also evaluate the transition from ordinary matter dominance, to dark matter dominance, for the cosmos as a whole. We obtain for the transition points, <em>z</em>=1.66, for susceptibility model I, and, <em style="white-space:normal;">z</em><span 展开更多
关键词 Extended Model of Gravity Dark Matter Dark Energy Cosmic Evolution of Density Parameters Gravitational Susceptibility of the Vacuum Vacuum Energy Polarization of Space
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A Lack of Evidence for Global Ram-Pressure Induced Star Formation in the Merging Cluster Abell 3266 认领
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作者 Mark J. Henriksen Scott Dusek 《天文学与天体物理学国际期刊(英文)》 2021年第1期95-132,共38页
Interaction between the intracluster medium and the interstellar media of galaxies via ram-pressure stripping (RPS) has ample support from both observations and simulations of galaxies in clusters. Some, but not all o... Interaction between the intracluster medium and the interstellar media of galaxies via ram-pressure stripping (RPS) has ample support from both observations and simulations of galaxies in clusters. Some, but not all of the observations and simulations show a phase of increased star formation compared to normal spirals. Examples of galaxies undergoing RPS induced star formation in clusters experiencing a merger have been identified in high resolution optical images supporting the existence of a star formation phase. We have selected Abell 3266 to search for ram-pressure induced star formation as a <em>global</em> property of a merging cluster. Abell 3266 (z = 0.0594) is a high mass cluster that features a high velocity dispersion, an infalling subcluster near to the line of sight, and a strong shock front. These phenomena should all contribute to making Abell 3266 an optimum cluster to see the global effects of RPS induced star formation. Using archival X-ray observations and published optical data, we cross-correlate optical spectral properties ([OII, H<em>β</em>]), indicative of starburst and post-starburst, respectively with ram-pressure, <em>ρ</em>v<sup>2</sup>, calculated from the X-ray and optical data. We find that post-starburst galaxies, classified as E + A, occur at a higher frequency in this merging cluster than in the Coma cluster and at a comparable rate to intermediate redshift clusters. This is consistent with increased star formation due to the merger. However, both starburst and post-starburst galaxies are equally likely to be in a low or high ram pressure environment. From this result, we infer that the duration of the starburst phase must be very brief so that: 1) at any time only a small fraction of the galaxies in a high ram pressure environment show this effect, and 2) most post-starburst galaxies are in an environment of low ram pressure due to their continued orbital motion in the cluster. 展开更多
关键词 X-RAY High Energy Galaxy Evolution Clusters of Galaxies
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The Planet’s Response to Human Activity. Thermodynamic Approach 认领
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作者 Vladimir Kh. Dobruskin 《生态学期刊(英文)》 2021年第2期126-135,共10页
The applicability of the laws of thermodynamics to processes on Earth is discussed and it is shown that the chemical thermodynamics provides the reasonable basis for predicting probable changes. The historical evoluti... The applicability of the laws of thermodynamics to processes on Earth is discussed and it is shown that the chemical thermodynamics provides the reasonable basis for predicting probable changes. The historical evolution of the planet is considered in the framework of the Harari approach;a civilization’s level is estimated by the Kardashev scale based on the amount of energy it is able to use. During a short historical interval (≈500 years), when the effect of biological evolution is imperceptible and the main changes on the planet are caused by human activity, two systems are considered: 1) a nonequilibrium inhabited planet and 2) a quasi-equilibrium hypothetical planet without people, which is accepted as a comparison system. It is shown that in response to the energy impact, the equilibrium of the hypothetical system with the primordial nature is disturbed and processes are initiated aimed to prevent further growth of energy production. In the case of a real planet, this implements changes preventing the uncontrolled activities of humans—the energy producers. Climate change, an increase in the number of natural disasters and epidemics can be recognized as a direct response of the planet, while changes in socio-economic relations, morality, demographic situation, new threats etc. can be considered as an indirect reaction to changing conditions of human beings. The latter results from the mutual correlation between the progress of society, on the one hand, and humanitarian and political processes, on the other. The role of renewable and non-renewable energy sources in evolution is taken into account. Obviously, it is better to take meaningful measures to achieve an acceptable balance now than to wait for the blind and extremely painful action of the laws of nature, which would lead to a reduction in the population. 展开更多
关键词 Planet’s Response Human Activity EVOLUTION
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Effect of Zn atom in Fe-N-C catalysts for electro-catalytic reactions: theoretical considerations 认领
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作者 Yongcheng Li Riming Hu +4 位作者 Zhibin Chen Xin Wan Jia-Xiang Shang Fu-He Wang Jianglan Shui 《纳米研究:英文版》 SCIE EI CSCD 2021年第3期611-619,共9页
Due to the high specific surface area,abundant nitrogen and micropores,ZIF-8 is a commonly used precursor for preparing high performance Fe-N-C catalysts.However,the Zn element is inevitably remained in the prepared F... Due to the high specific surface area,abundant nitrogen and micropores,ZIF-8 is a commonly used precursor for preparing high performance Fe-N-C catalysts.However,the Zn element is inevitably remained in the prepared Fe-N-C catalyst.Whether the residual Zn element affects the catalytic activity and active site center of the Fe-N-C catalyst caused widespread curiosity,but has not been studied yet.Herein,we built several Fe,Zn,and N co-doped graphene models to investigate the effect of Zn atoms on the electrocatalytic performance of Fe-N-C catalysts by using density functional theory method.The calculation results show that all the calculated Fe-Zn-Nx structures are thermodynamically stable due to the negative formation energies and relative stabilities.The active sites around Fe and Zn atoms in the structure of Fe-Zn-N6(III)show the lowest oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)overpotentials of 0.38 and 0.43 V,respectively.The bridge site of Fe-Zn in Fe-Zn-N5 shows the lowest ηHER of−0.26 V.A few structures with a better activity than that of FeN4 or ZnN4 are attributed to the synergistic effects between Fe and Zn atoms.The calculated ORR reaction pathways on Fe-Zn-N6(III)show that H2O is the final product and the ORR mechanism on the catalyst would be a four-electron process,and the existence of Zn element in the Fe-N-C catalysts plays a key role in reducing the ORR activation energy barrier.The results are helpful for the deep understand of high-performance Fe-N-C catalysts. 展开更多
关键词 Fe-N-C Zn-N-C oxygen reduction reaction oxygen evolution reaction hydrogen evolution reaction density functional theory
The Phenomenon of a Natural Thermonuclear Reactor 认领
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作者 Andrzej Pawuła 《地球科学和环境保护期刊(英文)》 2021年第2期92-109,共18页
The study contains the justification of J.M. Herndon’s thesis about the existence of a thermonuclear reactor in the Earth’s core. A scenario of the formation of a spontaneous nuclear reactor is presented, referring ... The study contains the justification of J.M. Herndon’s thesis about the existence of a thermonuclear reactor in the Earth’s core. A scenario of the formation of a spontaneous nuclear reactor is presented, referring to the universal law of gravity, to the relationship between matter and energy, and to the properties of plasma. The theoretical attitudes of the discussed phenomena and the relations between them can be called the Theory of the Primordial Forces of Nature. It includes the interactions of the gravitational field, the forces of the electromagnetic field, which determine the properties of matter, and the strong interactions resulting from the release of nuclear energy. Arguments for the thesis about the commonness of the phenomenon of thermonuclear reactors in space are presented. The second part of the article presents examples of geological phenomena that confirm the activity of a thermonuclear reactor in the center of the Earth. 展开更多
关键词 Globe Evolution Cycle Spontaneous Thermonuclear Reactor Primary Forces of Nature Theory
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改革开放以来我国职业教育经费保障的回顾与展望 认领
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作者 邹文芳 胡瑾缔 《职教通讯》 2021年第2期62-71,共10页
改革开放以来,我国职业教育经费保障政策演进经历了逐步恢复期、法制规范期、稳步发展期、全面深化期四个阶段。虽然职业教育经费保障政策为职业教育的健康稳定发展提供了积极的制度保证,但还存在着整体教育经费总量占比不高、生均经费... 改革开放以来,我国职业教育经费保障政策演进经历了逐步恢复期、法制规范期、稳步发展期、全面深化期四个阶段。虽然职业教育经费保障政策为职业教育的健康稳定发展提供了积极的制度保证,但还存在着整体教育经费总量占比不高、生均经费较低且区域差距较大、社会力量投入职业教育办学力度不够等问题。在新的历史时期,职业教育经费保障制度要适应职业教育发展的现实需要,须从持续加大政府财政拨款力度、基本落实职业教育生均经费标准以及完善多元化的职业教育经费筹措机制入手,以破解职业教育经费保障的难题。 展开更多
关键词 职业教育 经费保障 演进脉络 现存问题 改革趋势
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中国利用外资产业政策文献研究——基于量化质化演化三维框架 认领
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作者 崔新健 欧阳慧敏 《中央财经大学学报》 北大核心 2021年第1期96-108,共13页
中国利用外资产业政策文献数量和质量40年来有很大发展,对构建理论体系有重要学术价值。笔者以CNKI文献数据库为样本,采用内容分析法和CiteSpace、NVivo定量化分析工具,基于量化质化演化三维框架展开分析,文献归类到投资环境、外资方式... 中国利用外资产业政策文献数量和质量40年来有很大发展,对构建理论体系有重要学术价值。笔者以CNKI文献数据库为样本,采用内容分析法和CiteSpace、NVivo定量化分析工具,基于量化质化演化三维框架展开分析,文献归类到投资环境、外资方式、外资进入、外企管理、外资管理、外资效应6个主题,将文献发展分为探索尝试、调整强化、加入WTO、适应WTO和国际接轨5个阶段,以知识图谱显示文献主题分布及其关联性,从次主题阶段性重叠不断深化表明学术研究的进展,逐步揭示出中国利用外资产业政策文献演化的内在规律。研究结果表明:该领域已具备丰富的学术资源和强大的发展潜力;研究从政策应用型为主转向以学术探理型为主;学术领域演进呈现政策引致型演化模式;理论研究与国际前沿仍然存在差距,甚至存在盲点或薄弱区;研究领域逐步搭建国际话语平台。笔者基于上述研究结论认为:面临当今世界百年未有之大变局,我国学术界要基于世界规则变化趋势,加强学术探理型研究。 展开更多
关键词 外资产业政策 文献研究 演化 内容分析法
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A Topological Evolution Model Based on the Attraction of the Motif Vertex 认领
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作者 Xing Li Shuxin Liu +1 位作者 Yuhang Zhu Yingle Li 《中国通信:英文版》 SCIE CSCD 2021年第4期27-39,共13页
As a fundamental problem in the field of the network science,the study of topological evolution model is of great significance for revealing the inherent dynamics and mechanisms of complex network evolution.In order t... As a fundamental problem in the field of the network science,the study of topological evolution model is of great significance for revealing the inherent dynamics and mechanisms of complex network evolution.In order to study the influence of different scales of preferential attachment on topological evolution,a topological evolution model based on the attraction of the motif vertex is proposed.From the perspective of network motif,this model proposes the concept of attraction of the motif vertex based on the degree of the motif,quantifies the influence of local structure on the node preferential attachment,and performs the preferential selection of the new link based on the Local World model.The simulation experiments show that the model has the small world characteristic apparently,and the clustering coefficient varies with the scale of the local world.The degree distribution of the model changes from power-law distribution to exponential distribution with the change of parameters.In some cases,the piecewise power-law distribution is presented.In addition,the proposed model can present a network with different matching patterns as the parameters change. 展开更多
关键词 complex network topological evolution model network motif
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Effects of heat transfer in a growing particle layer on microstructural evolution during solidification of colloidal suspensions 认领
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作者 游家学 张运涵 +2 位作者 王志军 王锦程 刘生忠 《中国物理B:英文版》 SCIE EI CAS CSCD 2021年第2期540-548,共9页
Heat transfer is the foundation of freezing colloidal suspensions and a key factor for the interface movement.However,how the thermal conductivity of particles affects freezing microstructural evolution remains unknow... Heat transfer is the foundation of freezing colloidal suspensions and a key factor for the interface movement.However,how the thermal conductivity of particles affects freezing microstructural evolution remains unknown.Here in this work,a mathematical model is built up to investigate thermal interactions among a growing particle layer,pulling speeds,and the freezing interface under a thermal gradient.Experiments are conducted to confirm the tendency predictions of the model.With the increase of pulling speeds,the drifting distance of the freezing interface increases and the time to finish drifting decreases.When the thermal conductivity of particles(kp)is smaller than that of the surrounding(kw),the freezing interface tends to go forward to the warm side.Contrarily,the freezing interface tends to go back to the cold side when the thermal conductivity of particles is larger than that of the surrounding(α=kp/kw>1).It originates from the shape of the local freezing interface:convex(α<1)or concave(α>1).These morphological changes in the local interface modify the premelting drag force Ff.Whenα<1,Ffdecreases and the freezing morphology tends to be the frozen fringe.Whenα>1,Ffincreases and the freezing morphologies tend to be ice spears.These understandings of how the thermal conductivity of particles affect microstructural evolution may optimize the production of freeze-casting materials and their structural-functional properties. 展开更多
关键词 SOLIDIFICATION colloidal suspensions heat transfer microstructural evolution
Paleozoic convergence processes in the southwestern Central Asian Orogenic Belt:Insights from U–Pb dating of detrital zircons from West Junggar,northwestern China 认领
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作者 Pan Zhang Guocan Wang +2 位作者 Tianyi Shen Ali Polat Chengyu Zhu 《地学前缘:英文版》 SCIE CAS CSCD 2021年第2期531-548,共18页
The West Junggar orogen,located in the southwestern Central Asian Orogenic Belt(CAOB),preserves an abundant record of tectonic processes associated with the evolution of the Junggar Ocean.In this study,we use detrital... The West Junggar orogen,located in the southwestern Central Asian Orogenic Belt(CAOB),preserves an abundant record of tectonic processes associated with the evolution of the Junggar Ocean.In this study,we use detrital zircon U–Pb age data from Ordovician to Carboniferous sandstones in the southern and central West Junggar domains,complemented by literature data,to better constrain the tectonic evolution of the southwestern CAOB.The Kekeshayi,Qiargaye,and Laba formations in the southern West Junggar domain were deposited during the Darriwilian-Sandbian,Katian-Aeronian,and Homerian-Emsian,respectively.Detrital zircon provenances of these formations display a marked shift from the southern West Junggar domain to the Paleo-Kazakhstan Continent(PKC).This suggests that the southern West Junggar intra-oceanic arc might have gradually accreted to the northern margin of the PKC prior to the Emsian,which has significantly contributed to the lateral growth of the PKC.The Carboniferous strata,Xibeikulasi,Baogutu,and Tailegula formations,in the central West Junggar domain represent a coherent sequence of volcaniclastic turbidites and were deposited in a progressively shrinking remnant oceanic basin during the Visean to Moscovian.They contain unimodal detrital zircon distributions and are derived from the local and coeval magmatic rocks in the central West Junggar domain.We propose that the final closure of the Junggar Ocean likely occurred in the end of the Late Carboniferous in response to regional amalgamation events in the southwestern CAOB,which marks the final assembly of the Kazakhstan Orocline.The central and southern West Junggar domains underwent individual evolution in the Paleozoic,and were recombined by the significant intra-continental reworking along the large-scale strike-slip faults. 展开更多
关键词 CAOB West Junggar Detrital zircon Sedimentary provenances Paleozoic evolution
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Electrocatalytic and photocatalytic performance of noble metal doped monolayer MoS2 in the hydrogen evolution reaction: A first principles study 认领
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作者 Zheng Zhang Kai Chen +2 位作者 Qiang Zhao Mei Huang Xiaoping Ouyang 《纳米材料科学:英文版》 CAS CSCD 2021年第1期89-94,共6页
To maximize the catalytic performance of MoS2 in the hydrogen evolution reaction,we investigate the electrocatalytic and photocatalytic performance of monolayer MoS2 doped with noble metal(Ag,Au,Cu,Pd,and Pt)usi... To maximize the catalytic performance of MoS2 in the hydrogen evolution reaction,we investigate the electrocatalytic and photocatalytic performance of monolayer MoS2 doped with noble metal(Ag,Au,Cu,Pd,and Pt)using first principles calculation combined with the climbing image nudged elastic band method.We find the band gap of the monolayer MoS2 is reduced significantly by the noble metal doping,which is unfavorable to improving its photocatalytic performance.The optical absorption coefficient shows that the doping does not increase the ability of the monolayer MoS2 to absorb visible light.The monolayer MoS2 doped with the noble metal is not a potential photocatalyst for the hydrogen evolution reaction because the band edge position of the conduction band minimum is lower than-4.44 eV,the reduction potential of H+/H2.Fortunately,the band gap reduction increases the electron transport performance of the monolayer MoS2,and the activation energy of water splitting is greatly reduced by the noble metal doping,especially the Pt doping.On the whole,noble metal doping can enhance the electrocatalytic performance of the monolayer MoS2. 展开更多
关键词 ELECTROCATALYTIC Monolayer MoS2 Noble metal doping Hydrogen evolution reaction First principles calculation
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Non-metallic electronic regulation in CuCo oxy-/thio-spinel as advanced oxygen evolution electrocatalysts 认领
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作者 Huan Yang Shuai Gao +7 位作者 Dewei Rao Chaonan Zhang Xuecheng Zhou Shaokang Yang Jingjing Ye Shasha Yang Feili Lai Xiaohong Yan 《中国科学:化学英文版》 SCIE EI CAS CSCD 2021年第1期101-108,共8页
Developing cost-effective and high-performance oxygen evolution reaction(OER)electrocatalysts has become the intense research on pursuing emerging renewable energy conversion,in which exploring and investigating the i... Developing cost-effective and high-performance oxygen evolution reaction(OER)electrocatalysts has become the intense research on pursuing emerging renewable energy conversion,in which exploring and investigating the intrinsic nature of efficient and stable Cu Co spinel catalysts toward OER in alkaline media is highly desirable.Herein,Cu1–xCo2+xO4oxy-spinel nanoflakes are fabricated by a facile hydrothermal method with the oxidation of ammonia water.In the same condition,Cu1–xCo2+xS4thio-spinel nanospheres are formed without oxidation.In OER process,the as-obtained Cu1–xCo2+xO4nanoflakes and Cu1–xCo2+xS4nanospheres possess the anodic overpotential of 267 and 297 m V in alkaline media to drive the current density of 10 m A/cm^2,respectively,outperforming the state-of-the-art noble metal catalyst of RuO2.X-ray photoelectron spectroscopy analysis exhibits the higher ratio value of Co(Ⅲ)/Co(Ⅱ)in Cu1–xCo2+xO4than that in Cu1–xCo2+xS4,suggesting that the stronglyelectronegative oxygen efficiently predominates in regulating valence states of Co active sites in spinel structures.Remarkably,density functional theory simulation further reveals that the increased valence state of Co could accelerate the electron exchange between catalysts and oxygen adsorbates during electrocatalysis,thus contributing to the higher OER activity of Cu1–xCo2+xO4catalysts.This work provides deep insight regarding the significance of non-metal element(O and S)in Cu Co spinel structure catalysts,as well as presents a promising approach to exploit higher performance and grasp the mechanism of various non-noblemetal spinel catalysts for water oxidation. 展开更多
关键词 copper-cobalt oxy-spinel thio-spinel oxygen evolution reaction density functional theory
Surface defect-rich ceria quantum dots anchored on sulfur-doped carbon nitride nanotubes with enhanced charge separation for solar hydrogen production 认领
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作者 Mengru Li Changfeng Chen +3 位作者 Liping Xu Yushuai Jia Yan Liu Xin Liu 《能源化学:英文版》 SCIE EI CAS CSCD 2021年第1期51-59,I0003,共10页
Designing defect-engineered semiconductor heterojunctions can effectively promote the charge carrier separation.Herein,novel ceria(CeO2) quantum dots(QDs) decorated sulfur-doped carbon nitride nanotubes(SCN NTs) were ... Designing defect-engineered semiconductor heterojunctions can effectively promote the charge carrier separation.Herein,novel ceria(CeO2) quantum dots(QDs) decorated sulfur-doped carbon nitride nanotubes(SCN NTs) were synthesized via a thermal polycondensation coupled in situ depositionprecipitation method without use of template or surfactant.The structure and morphology studies indicate that ultrafine CeO2 QDs are well distributed inside and outside of SCN NTs offering highly dispersed active sites and a large contact interface between two components.This leads to the promoted formation of rich Ce3+ ion and oxygen vacancies as confirmed by XPS.The photocatalytic performance can be facilely modulated by the content of CeO2 QDs introduced in SCN matrix while bare CeO2 does not show activity of hydrogen production.The optimal catalyst with 10% of CeO2 loading yields a hydrogen evolution rate of 2923.8 μmol h-1 g-1 under visible light,remarkably higher than that of bare SCN and their physical mixtures.Further studies reveal that the abundant surface defects and the created 0 D/1 D junctions play a critical role in improving the separation and transfer of charge carriers,leading to superior solar hydrogen production and good stability. 展开更多
关键词 Photocatalytic hydrogen evolution Ceria quantum dots Sulfur-doped carbon nitride nanotubes Surface defects Charge separation
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FeCo alloy@N-doped graphitized carbon as an efficient cocatalyst for enhanced photocatalytic H2 evolution by inducing accelerated charge transfer 认领
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作者 Sibo Chen Yun Hau Ng +6 位作者 Jihai Liao Qiongzhi Gao Siyuan Yang Feng Peng Xinhua Zhong Yueping Fang Shengsen Zhang 《能源化学:英文版》 SCIE EI CAS CSCD 2021年第1期92-101,I0004,共11页
Cocatalysts play important roles in improving the activity and stability of most photocatalysts.It is of great significance to develop economical,efficient and stable cocatalysts.Herein,using Na2CoFe(CN)6 complex as p... Cocatalysts play important roles in improving the activity and stability of most photocatalysts.It is of great significance to develop economical,efficient and stable cocatalysts.Herein,using Na2CoFe(CN)6 complex as precursor,a novel noble-metal-free FeCo@NGC cocatalyst(nano-FeCo alloy@N-doped graphitized carbon) is fabricated by a simple pyrolysis method.Coupling with g-C3 N4, the optimal FeCo@NGC/g-C3N4 receives a boosted visible light driven photocatalytic H2 evolution rate of 42.2 μmol h-1, which is even higher than that of 1.0 wt% Pt modified g-C3N4 photocatalyst.Based on the results of density functional theory(DFT) calculations and practical experiment measurements,such outstanding photocatalytic performance of FeCo@NGC/g-C3N4 is mainly attributed to two aspects.One is the accelerated charge transfer behavior,induced by a photogene rated electrons secondary transfer performance on the surface of FeCo alloy nanoparticles.The other is related to the adjustment of H adsorption energy(approaching the standard hydrogen electrode potential) by the presence of external NGC thin layer.Both factors play key roles in the H2 evolution reaction.Such outstanding performance highlights an enormous potential of developing noble-metal-free bimetallic nano-alloy as inexpensive and efficient cocatalysts for solar applications. 展开更多
关键词 FeCo alloy nanoparticles COCATALYST N-doped graphitized carbon g-C3N4 Visible light Hydrogen evolution
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Boosting pH-Universal Hydrogen Evolution of Molybdenum Disulfide Particles by Interfacial Engineering 认领
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作者 Liling Liao Lun Yang +5 位作者 Gang Zhao Haiqing Zhou Fengming Cai Yi Li Xiuzhang Wang Fang Yu 《中国化学:英文版》 SCIE CAS CSCD 2021年第2期288-294,共7页
The design of high-efficiency non-noble and earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is highly paramount for water splitting and renewable energy systems.Molybdenum disulfide(MoS2)with ab... The design of high-efficiency non-noble and earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is highly paramount for water splitting and renewable energy systems.Molybdenum disulfide(MoS2)with abundant edge sites can be utilized as a promising alternative,but its catalytic activity is greatly related to the pH values,especially in an alkaline environment due to the extremely high energy barriers for water adsorption and dissociation steps.Here we report an exceptionally efficient and stable electrocatalyst to improve the sluggish HER process of layered MoS2particles in different pH electrolytes,especially in base.The electrocatalyst is constructed by in situ growing selenium-doped MoS2(Se-MoS2)nanoparticles on three-dimensional cobalt nickel diselenide(mCo0.2Ni0.8Se2)nanostructured arrays.Due to the large number of active edge sites of Se-MoS2particles exposed at the surface,robust electrical conductivity and large surface area of mCo0.2Ni0.8Se2support,and strong interfacial interactions between Se-MoS2and mCo0.2Ni0.8Se2,this hybrid catalyst shows very outstanding catalytic HER properties featured by low overpotentials of 30 and 122 mV at 10 and 100 mA/cm2with good operational stability in base,respectively,which outperforms most of inexpensive catalysts consisting of layered MoS2,transition metal selenides and sulfides,and it performs as well as noble Pt catalysts.Meanwhile,this electrocatalyst is also very active in neutral and acidic electrolytes,requiring low overpotentials of 93 and 94 mV at 10 mA/cm2,respectively,demonstrating its superb pH universality as a HER electrocatalyst with excellent catalytic durability.This study provides a straightforward strategy to construct an efficient non-noble electrocatalyst for driving the HER kinetics in different electrolytes. 展开更多
关键词 Hydrogen evolution reaction Molybdenum disulfide pH-universal Water splitting Heterogeneous catalysis
共享零售:演化、流程与实施 认领
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作者 王家玮 《齐齐哈尔大学学报:哲学社会科学版》 2021年第1期62-65,共4页
近年来,共享经济作为经济发展新常态,正悄然改变着各行业发展模式。共享零售作为结合共享经济与新零售的新型模式,受到学术界及企业界多方关注,但少有学者对共享零售的流程与实施进行分析总结。通过梳理共享零售演化过程,结合国美模式,... 近年来,共享经济作为经济发展新常态,正悄然改变着各行业发展模式。共享零售作为结合共享经济与新零售的新型模式,受到学术界及企业界多方关注,但少有学者对共享零售的流程与实施进行分析总结。通过梳理共享零售演化过程,结合国美模式,总结共享零售一般性交易流程可以看出,它以高度整合的全渠道为基础,将以佣金为目的的消费者引入商业链,通过共享平台信息技术整合了消费者社交资源,消费者以分享商品服务及购物体验的方式扩大信息覆盖的广度及深度,最终通过不同主体间互动及协同完成交易。开展共享零售的企业,应从购前、购中、购后三个阶段有针对性制定策略。 展开更多
关键词 共享零售 演化 交易流程 实施策略
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Microstructure and mechanical properties in the TLP joint of FeCoNiTiAl and Inconel 718 alloys using BNi2 filler 认领
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作者 Lin Yuan Jiangtao Xiong +3 位作者 Yajie Du Jin Ren Junmiao Shi Jinglong Li 《材料科学技术:英文版》 SCIE EI CAS CSCD 2021年第2期176-185,共10页
High entropy alloy(HEA) of Fe Co Ni Ti Al and Inconel 718 superalloy were firstly transient liquid phase(TLP) bonded by BNi2 filler due to the diffusion of Si and B in the filler to the base metals. The effects of bon... High entropy alloy(HEA) of Fe Co Ni Ti Al and Inconel 718 superalloy were firstly transient liquid phase(TLP) bonded by BNi2 filler due to the diffusion of Si and B in the filler to the base metals. The effects of bonding time on microstructure evolution and mechanical properties of the TLP joints were investigated.Owing to the complete isothermal solidification of the joints bonded for 30 min 120 min at 1100°C,no athermally solidified zones(ASZs) formed by eutectic phases were observed in the welded zone. Thus the TLP joints were only composed by the isothermally solidified zone(ISZ) and two diffusion affected zone(DAZ) adjacent to the dissimilar base metals and the negative effect of the ASZ on joint properties can be avoided. In addition, the increase of the bonding time can also make the Ti B2 borides precipitated in the DAZ near HEA and the brittle borides or carbides in the DAZ near IN718 alloy decrease and reduce the possibility of the stress concentration happened in the joints under loading. Therefore, the highest shear strength(632.1 MPa) of the TLP joints was obtained at 1100°C for 120 min, which was higher than that of the joint bonded for 30 min, 404.2 MPa. Furthermore, the extension of the bonding time made the fracture mechanism of the joint be transformed from the intergranular fracture to the transgranular fracture. However, as the brittle borides in the DAZ near IN718 can not be eliminated completely and refining of grains also happened in such region, all the TLP joints fractured inner the DAZ near IN718 alloy. 展开更多
关键词 FeCoNiTiAl alloy Inconel 718 alloy Microstructure evolution Mechanical properties Fracture mechanism
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