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β-cyclodextrin as Lithium-ion Diffusion Channel with Enhanced Kinetics for Stable Silicon Anode

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Energy & Environmental Materials 2021年第1期4卷 72-80页

作者： Pengcheng Li gen chen Ning Zhang Renzhi Ma Xiaohe Liu State Key Laboratory of Powder Metallurgy and School of Materials Science and Engineering Central South UniversityChangsha Hunan 410083China International Center for Materials Nanoarchitectonics(MANA) National Institute for Materials Science(NIMS)Namiki 1-1Tsukuba Ibaraki 305-0044Japan School of Chemical Engineering and Energy Zhengzhou UniversityChangsha Hunan 410083China

Silicon(Si)is regarded as a promising anode material for next-generation lithium-ion batteries due to its ultrahigh theoretical ***,the drastic volume change and the continuous solid electrolyte interphase(SEI)formation during the lithiation/delithiation process seriously hinder its practical application as commercial ***,macrocyclic betacyclodextrin(β-CD)has been designed as the diffusion channel for lithium ions at the molecular *** diameter of molecular channel is approximately comparable with the solvated lithium ions,which enables the transport of lithium ions and prevents the penetration of solvent ***,the addition ofβ-CD changes the formation behavior of SEI layer and stabilizes the Si *** enhanced electrochemical performances in terms of fast kinetics and improved stability have been *** Si anode with the particularly selected lithium-ion diffusion channel and stabilized SEI layer exhibits a high reversible capability of 2562 m Ah g-1 after 50 cycles at the current density of 500 m A g-1,1944 m Ah g-1 after 200 cycles at the current density of 1 A g-1,and high rate *** novel strategy of molecular channel for lithium-ion diffusion offers new insights into the design of alloy-typed anode electrodes with high capacity for lithium-ion batteries.

关键词： lithium-ion batteries lithium-ion diffusion channel Silicon solid electrolyte interphase β-cyclodextrin

Neutron excess method for performance assessment of thoriumbased fuel in a breed-and-burn reactor with various coolants

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Nuclear Science and Techniques 2016年第4期27卷 167-173页

作者： Kun Yang Wei Qin Jin-gen chen Xiang-Zhou Cai Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China CAS Center for Excellence in TMSR Energy System Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049 China

Fertile fuel, such as thorium or depleted uranium, can be bred into fissile fuel and burnt in a breed-andburn(B&B) reactor. Modeling a full core with fertile fuel can assess the performance of a B&B reactor with exact quantitative estimates, but costs too much computation time. For simplicity, performing the recently developed neutron balance method with a zero-dimensional(0-D)model can also provide a reasonable result. Based on the0-D model, the feasibility of the B&B mode for thorium fuel in a fast reactor cooled by sodium was investigated by considering the(n, 2n) and(n, 3n) reaction rates of fuel and coolant in this work, and compared with that of depleted uranium fuel. Afterward, the performance of the same thorium-based fuel core, but cooled by helium, lead-bismuth, and FLi Be, respectively, is discussed. It is found that the(n, 2n) and(n, 3n) reactions should not be neglected for the neutron balance calculation for thorium-based fuel to sustain the B&B mode of operation.

关键词：性能评估钠燃料冷却剂反应器中子燃烧零维模型化学反应速率

Salt-induced Electron Transfer Photooxidation of Cholesterol in Nonpolar Solvents

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Chemical Research in Chinese Universities 1997年第4期13卷 112-116页

作者： YANG chen gen WAN Yan JIANG Zhi qin Department of Organic Chemistry Agricultural CollegeYangzhou UniversityYangzhou225009 Analysis and Research Center Tongji UniversityShanghai200092

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关键词： Cholesterol Photooxygenation Salt induced Electron transfer

Two-level hierarchical feature learning for image classification

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Frontiers of Information Technology & Electronic Engineering 2016年第9期17卷 897-906页

作者： Guang-hui SONG Xiao-gang JIN gen-lang chen Yan NIE College of Computer Science and Technology Zhejiang University Ningbo Institute of Technology Zhejiang University College of Science and Technology Ningbo University

In some image classification tasks, similarities among different categories are different and the samples are usually misclassified as highly similar categories. To distinguish highly similar categories, more specific features are required so that the classifier can improve the classification performance. In this paper, we propose a novel two-level hierarchical feature learning framework based on the deep convolutional neural network(CNN), which is simple and effective. First, the deep feature extractors of different levels are trained using the transfer learning method that fine-tunes the pre-trained deep CNN model toward the new target dataset. Second, the general feature extracted from all the categories and the specific feature extracted from highly similar categories are fused into a feature vector. Then the final feature representation is fed into a linear classifier. Finally, experiments using the Caltech-256, Oxford Flower-102, and Tasmania Coral Point Count(CPC) datasets demonstrate that the expression ability of the deep features resulting from two-level hierarchical feature learning is powerful. Our proposed method effectively increases the classification accuracy in comparison with flat multiple classification methods.

关键词： Transfer learning Feature learning Deep convolutional neural network Hierarchical classification Spectral clustering

Sediment transport in pure acceleration-skewed oscillatory sheet flow

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Journal of Hydrodynamics 2018年第6期30卷 1045-1054页

作者： Xin chen Fu-jun Wang gen-fa chen Liu-chao Qiu College of Water Resources and Civil Engineering China Agricultural University Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System China Agricultural University China Institute of Water Resources and Hydropower Research

In the present study, an analytical concept model is built, using a two-phase model for the sediment transport in a pure acceleration-skewed oscillatory sheet flow. The analytical model is based on the asymmetric wave theory, the irregular boundary layer theory and the exponential concentration distribution theory, to be used for analyzing the phase lag and the boundary layer development related to the acceleration skewness. The two-phase model is applied for the calculations of the instantaneous erosion depth, the sediment flux, the boundary layer thickness and the sediment transport rate, as well as the differences between the positive acceleration stage and the negative acceleration stage caused by the acceleration skewness, as very important in the net current and sediment transport. The effects of the sediment diameter and the phase lag are explained by a comparison with the instantaneous type empirical formula, as is closely related to the acceleration skewness. With the analytical concept model and the two-phase model, the generation of the net sediment transport in the pure acceleration-skewed flows is clearly explained. The phase lag effect is important for the instantaneous sediment transport in the pure acceleration-skewed flow, whereas the boundary layer development difference between the positive acceleration stage and the negative acceleration stage plays a major role in the determination of the net sediment transport.

关键词： Acceleration skewness analytical concept model boundary layer thickness two-phase model sediment transport rate

A Mutation of OSOTP 51 Leads to Impairment of Photosystem I Complex Assembly and Serious Photo-damage in Rice

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Journal of Integrative Plant Biology 2012年第2期54卷 87-98页

作者： Jian-Wei Ye Zi-Ying Gong Chun-Guang chen Hua-Ling Mi gen-Yun chen National Key Laboratory of Plant Molecular genetics Institute of Plant Physiology and Ecology Shanghai Institutes for Biological SciencesChinese Academy of Sciences Shanghai 200032 China

gene expression in chloroplasts is regulated by many nuclear-encoded proteins. In this study, we isolated a rice （Oryza sativa subsp, japonica） mutant osotp51 with significant reduction in photosystem I （PSI）. The osotp51 is extremely sensitive to light and accumulates a higher level of reactive oxygen species. Its leaves are almost albino when grown at 40 ~mol photons/m2 per s. However, grown at 4 umol photons/m2 per s, osotp51 has a similar phenotype to the wild-type. 77K chlorophyll fluorescence analysis showed a blue shift in the highest peak emission from PSI in osotp51. In addition, the level of PSI and PSII dimer is dramatically reduced in osotp51. OSOTP 51 encodes a pentatricopeptide repeats protein, homologous to organelle transcript processing 51 in Arabidopsis. Loss-of-function OSOTP51 affects intron splicing of a number of plastid genes, particularly the ycf3 coding a protein involved in the assembly of PSI complex. OSOTP51 is functionally conserved in higher plants. The mutation of osotp51 indirectly leads to a widespread change in the structure and functions of PSI, results in severe photoinhibition, and finally dies, even when grown under very low light intensity.

关键词： Chloroplast photoprotection photosynthesis splicing ycf3

Bio-inspired synthesis of nanomaterials and smart structures for electrochemical energy storage and conversion

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Nano Materials Science 2020年第3期2卷 264-280页

作者： Mei Ding gen chen Weichuan Xu Chuankun Jia Hongmei Luo College of Materials Science and Engineering Changsha University of Science and TechnologyChangshaHunan410114PR China School of Materials Science and Engineering Central South UniversityChangshaHunan410083PR China Chemical and Materials Engineering Department New Mexico State UniversityNM88003United States

Traditional synthetic methodologies are confronted with great challenges to fabricate complex nanomaterials with delicate design,high efficiency and excellent *** the past decade,bio-inspired synthesis has been extensively applied as an effective and efficient strategy for the fabrication of nanomaterials and *** electrode materials at nanoscale in the aspect of either structure or functionality has been receiving surging interest because of their incomparable advantages and outperforming *** this review,we summarize the recent progresses on bio-inspired synthesis of nanomaterials and smart structures in the field of energy storage and ***,an overall introduction of bio-inspired synthetic strategies will be presented,with focus on the biotemplates and *** that,a library of complex mimicking structures featured by high-order,hierarchical porosity,or bionic function are introduced,with discussion on their chemical and physical properties associated with the *** enhanced electrochemical properties such as energy density,cycling stability,*** different electrochemical systems will be also *** last,we will expand the perspectives regarding the advantages and limitations of bioinspired strategy and possible solutions in the future.

关键词： properties. structure. synthesis

Engineering of carbon and other protective coating layers for stabilizing silicon anode materials

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Carbon Energy 2019年第2期1卷 219-245页

作者： Fenglin Wang gen chen Ning Zhang Xiaohe Liu Renzhi Ma State Key Laboratory of Powder Metallurgy School of Materials Science and EngineeringCentral South UniversityChangshaHunanChina

Silicon(Si)has been attracting extensive attention for rechargeable lithium(Li)‐ion batteries due to its high theoretical capacity and low potential vs Li/Li+.However,it remains challenging and problematic to stabilize the Si materials during electrochemical cycling because of the huge volume expansion,which results in losing electric contact and pulverization of Si ***,the Si anode materials generally suffer from poor cycling,poor rate performance,and low coulomb efficiency,preventing them from practical ***‐to‐date,there are numerous reports on the engineering of Si anode materials at microscale and nanoscale with significantly improved electrochemical *** this review,we will concentrate on various precisely designed protective layers for silicon‐based materials,including carbon layers,inorganic layers,and conductive polymer protective ***,we briefly introduced the alloying and failure mechanism of Si as anode materials upon electrochemical *** that,representative cases have been introduced and summarized to illustrate the purpose and advancement of protective coating layers,for instance,to alleviate pulverization and improve conductivity caused by volume expansion of Si particles during charge/discharge process,and maintain the surface stability of Si particles to form a stable solid‐electrolyte interphase *** last,possible strategies on the protective coating layer for stabilizing silicon anode materials that can be applied in the future have been indicated.

关键词： silicon carbon protective layer lithium storage

Analysis of Th-U breeding capability for an accelerator-driven subcritical molten salt reactor

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Nuclear Science and Techniques 2018年第8期29卷 218-226页

作者： Xue-Chao Zhao De-Yang Cui Xiang-Zhou Cai Jin-gen chen Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China CAS Innovative Academies in TMSR Energy System Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

Accelerator-driven systems based on molten salt fuel have several unique advantages and features for advanced nuclear fuel *** aim of this work was to study the Th-U breeding capability in such systems,known as‘‘accelerator-driven subcritical molten salt reactors’’(ADS–MSRs).Breeding capacities including conversion ratio and net^(233)U production for various subcriticalities and different minor actinides(MA)loadings were analyzed for an ADS–*** results show that the subcriticality of the core has a considerable effect on the Th-U breeding.A high subcriticality is favorable to improving the conversion ratio,increasing the net^(233)U production,and reducing the doubling ***,the doubling time for k_(eff)of 0.99 is larger than 80 years,while the counterpart for k_(eff)of 0.93 is only approximately22 ***,in an ADS–MSR with a high initial MA loading,MA results in a non-negligible^(233)U depletion in the first two decades,while increasing the net^(233)U production compared to reactors without MA *** the 50 years of operation,for the subcritical reactor(k_(eff)0:97)with MA fraction increasing from 1 to 14%,the net^(233)U production increases from 3.94 to 8.24 t.

关键词：加速器驱动反应堆熔融能力星期盐 MSR net