检索结果-南通市图书馆

Structural Optimization of Metal Oxyhalide for CO2 Reduction with High Selectivity and Current Density

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2020年第12期38卷 1752-1756页

作者： Fan-Lu Meng Qi Zhang Yan-xin duan Kai-Hua Liu xin-Bo Zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunJilin 130022China Key Laboratory of Automobile Materials Ministry of Education and College of Materials Science and EngineeringJilin UniversityChangchunJilin 130012JilinChina Hunon Key Laboratory for Micro-Nono Energy Materials and Device Department of PhysicsXiangton UniversityXiangtanHunan 411105China

of main observation and conclusion Flectrochemical CO2 reduction into value-added liquid fuels using CO2 neutral renewable energy sourcesis very promising to solve climatic *** order to realie their practical applications,highly active and inexpensive elecrocatalyts are urgently *** this study we have experimentlly achieved high electrocatalytic activty towards CO2 reduction for the synthesis of formate with an enhancedcurrent density of 15.1 mA·cm^-2 and significantly improved Farapaic efficiency of 98.4%upon electrochemical reduced ultrathin bismuth ***,the stable performance during 24h of operation is also ***,by detecting the exposed cystal plane after surface reorganization and applying density functional theory calculations,the possitle reaction pathways and catalytic active plane of the derved bismuthcatalyst are put forward,which would offer basic and design principles to directly develop the optimized metal Bi atalysts for enhanced electrocatalyticco conversion to formate.

关键词： bismuth halide furthermore

The Connection between the Sea Surface Height Anomaly Preceding the Indian Ocean Dipole and Summer Rainfall in China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2015年第4期8卷 238-243页

作者： duan xin-Yu LIU Na LI Shuanglin College of Atmospheric Science Plateau Atmosphere and Environment Key Laboratory of Sichuan Province Chengdu University of Information Technology Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Climate Change Research Center Institute of Atmospheric Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

The sea surface height anomaly(SSHA) signals leading the fall Indian Ocean Dipole(IOD) are investigated. The results suggest that, prior to the IOD by one year, a positive SSHA emerges over the western-central tropical Pacific(WCTP), which peaks during winter(January-February-March, JFM), persists into late spring and early summer(April-May-June, AMJ), and becomes weakened later on. An SSHA index, referred as to SSHA_WCTP, is defined as the averaged SSHA over the WCTP during JFM. The index is not only significantly positively correlated with the following-fall(September-October-November, SON) IOD index, but also is higher than the autocorrelation of the IOD index crossing the two different seasons. The connection of SSHA_ WCTP with following-summer rainfall in China is then explored. The results suggest that higher(lower) SSHA_ WCTP corresponds to increased(reduced) rainfall over southern coastal China, along with suppressed(increased) rainfall over the middle–lower reaches of the Yangtze River, North China, and the xinjiang region of northwestern China. Mechanistically, following the preceding-winter higher(lower) SSHA_WCTP, the South Asia High and the Western Pacific Subtropical High are weakened(intensified), which results in the East Asian summer monsoon weakening(intensifying). Finally, the connection between SSHA_WCTP and El Ni?o-Southern Oscillation(ENSO) is analyzed. Despite a significant correlation, SSHA_WCTP is more closely connected with summer rainfall. This implies that the SSHA_WCTP index in the preceding winter is a more effective predictor of summer rainfall in comparison with ENSO.

关键词： sea surface height Indian Ocean Dipole summer rainfall in China ENSO

TwinNet: Twin Structured Knowledge Transfer Network for Weakly Supervised Action Localization

在线全文

学校读者我要写书评

暂无评论

Machine Intelligence Research 2022年第3期19卷 227-246页

作者： Xiao-Yu Zhang Hai-Chao Shi Chang-Sheng Li Li-xin duan Institute of Information Engineering Chinese Academy of SciencesBeijing 100093China School of Computer Science Beijing Institute of TechnologyBeijing 100081China School of Computer Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

Action recognition and localization in untrimmed videos is important for many applications and have attracted a lot of attention. Since full supervision with frame-level annotation places an overwhelming burden on manual labeling effort, learning with weak video-level supervision becomes a potential solution. In this paper, we propose a novel weakly supervised framework to recognize actions and locate the corresponding frames in untrimmed videos simultaneously. Considering that there are abundant trimmed videos publicly available and well-segmented with semantic descriptions, the instructive knowledge learned on trimmed videos can be fully leveraged to analyze untrimmed videos. We present an effective knowledge transfer strategy based on inter-class semantic relevance. We also take advantage of the self-attention mechanism to obtain a compact video representation, such that the influence of background frames can be effectively eliminated. A learning architecture is designed with twin networks for trimmed and untrimmed videos, to facilitate transferable self-attentive representation learning. Extensive experiments are conducted on three untrimmed benchmark datasets (i.e., THUMOS14, ActivityNet1.3, and MEXaction2), and the experimental results clearly corroborate the efficacy of our method. It is especially encouraging to see that the proposed weakly supervised method even achieves comparable results to some fully supervised methods.

关键词： Knowledge transfer weakly supervised learning self-attention mechanism representation learning action localization

Integration of artificial intelligence and multi-omics in kidney diseases

在线全文

学校读者我要写书评

暂无评论

Fundamental Research 2023年第1期3卷 126-148页

作者： Xu-Jie Zhou Xu-Hui Zhong Li-xin duan Renal Division Peking University First HospitalBeijing 100034China Kidney Genetics Center Peking University Institute of NephrologyBeijing 100034China Key Laboratory of Renal Disease Ministry of Health of ChinaBeijing 100034China Key Laboratory of Chronic Kidney Disease Prevention and Treatment(Peking University) Ministry of EducationBeijing 100034China Department of Pediatrics Peking University First HospitalBeijingChina The Big Data Research Center University of Electronic Science and Technology of ChinaNo.2006Xiyuan AveWest Hi-Tech ZoneChengdu 611731China

Kidney disease is a leading cause of death ***,the diagnosis of kidney diseases and the grading of their severity are mainly based on clinical features,which do not reveal the underlying molecular *** recent surge of∼omics studies has greatly catalyzed disease *** advent of artificial intelligence(AI)has opened the avenue for the efficient integration and interpretation of big datasets for discovering clinically actionable *** review discusses how AI and multi-omics can be applied and integrated,to offer opportunities to develop novel diagnostic and therapeutic means in kidney *** combination of new technology and novel analysis pipelines can lead to breakthroughs in expanding our understanding of disease pathogenesis,shedding new light on biomarkers and disease classification,as well as providing possibilities of precise treatment.

关键词： Artificial intelligence Kidney diseases Multi-omics Network Pathway Precision medicine

Study on Phase Transformation Behavior of Strain-induced PLLA Mesophase by Polarized Infrared Spectroscopy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2019年第3期37卷 253-257页

作者： Jian Hu Li-Li Han Tong-Ping Zhang Yong-xin duan Jian-Ming Zhang Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics Qingdao University of Science& Technology

The structural transformation of mesophase to crystalline phase of strain-induced poly(L-lactic acid) has been investigated by differential scanning calorimetry(DSC) and in situ temperature dependent polarized Fourier transform infrared(FTIR) spectroscopy. It is found that, as the drawing temperature increases, melting of strain-induced mesophase in the heating process can remarkably interfere the crystallization behavior subsequently. Coupling with in situ polarized FTIR, from 60 °C to 76 °C, the mesophase melts partially rather than completely melting, and changes immediately to three-dimensional ordered structure. Of particular note, through monitoring the subtle spectral change in the critical phase transformation temperature from 60 °C to 64 °C, it is clearly demonstrated that relaxation of oriented amorphous chains initially takes place prior to the melting of mesophase.

关键词： Structural transformation Mesophase Strain-induced Polarized IR spectroscopy

Marginal cost pricing for coal fired electricity in coastal cities of China:The case of Mawan Electricity Plant in Shenzhen City, China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2003年第3期15卷 401-412页

作者： ZHANG Shi-qiu, duan Yan-xin (Center for Environmental Sciences, Peking University, Beijing 100871, China.) Center for Environmental Sciences Peking University 北京 100871

By developing a GDMOD model to estimate the environmental externalities associated with electricity generation, this project provides a detailed analysis of the damages and costs caused by different pollutants at varying distances from the Mawan Electricity Plant in Shenzhen, China. The major findings of this study can be summarized that (1) environmental damages caused by electricity production are large and are mainly imposed on regions far away from the electricity plant; (2) air pollution is the most significant contributor to the total damages, and SO_2, NOx, and particulate matter are the three major pollutants with highest damages; (3) the damages caused per unit of particulate, NOx, and SO_2 emissions are much higher than pollution treatment and prevention costs. The research results of this project showed that China needs to have a more effective levy system on SO_2, and a more manageable electricity tariff mechanism to internalize the environmental externalities. The results have also implications for pollution control strategies, compensation schemes as well as emission trading arrangements.

关键词： marginal cost pricing environmental damages environmental policy

NUMERICAL INVESTIGATION ON MUD BED-GENERATION AND IMPACTING A WALL ALONG A SLOPE

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2002年第2期14卷 7-11页

作者： Yue, Peng-Tao Xu, Sheng-Li Liu, Da-You duan, xin-Ping Univ. of Sci. and Technol. of China Hefei 230026 China Inst. of Mech. Chinese Acad. of Sci. Beijing 100080 China

In this paper mud was treated as the Bingham fluid. In staggered grids, two-dimensional incompressible Navier-Stokes equations for non-Newtonian fluid was solved by the MAC method. Numerical simulations were conducted on mud bed-generating phenomenon and mud impacting a wall along a slope. The distributions of free surface, pressure and velocity of mud and water were obtained. The results indicate that the computed layer thickness of mud bed almost equals the theoretically predicted value. Because of the differences in constitutive relationship, the distributions of free surface are different for water and mud. The distortion of water free surface is much more complicated.

关键词： Computer simulation Incompressible flow Navier Stokes equations Non Newtonian liquids Slope stability Two dimensional

Tetramethylguanidium Lactate Ionic Liquid: Catalyst-free Medium for Michael Addition Reaction

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2008年第1期24卷 36-41页

作者： LIANG Da-peng xin xin duan Hai-feng YIN Yan-zhen GAO Han LIN Ying-jie XU Jia-ning Department of Organic Chemistry College of Chemistry Jilin University Changchun 130012 P. R. China

A catalyst-free, facile and efficient Michael addition reaction of active methylene compounds as well as nitromethane with chalcones catalyzed by guanidinium lactate ionic liquid was done. A series of chalcones, nitromethane, and active methylene compounds were converted smoothly to the corresponding products in high yields. The simple procedure, very mild conditions, high yields, and reuse of the IL without any loss of catalytic activity make this protocol considerably attractive for academic researches and practical applications.

关键词： Guanidinium lactate ionic liquid Michael addition reaction Chalcone Active methylene compound

High Performance of PVA Nanocomposite Reinforced by Janus-like Asymmetrically Oxidized Graphene:Synergetic Effect of H-bonding Interaction and Interfacial Crystallization

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2022年第4期40卷 373-383页

作者： Ning Zhang Bin Zhang Yong Pang Hong-Sheng Yang Lu Zong Yong-xin duan Jian-Ming Zhang Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plasticsQingdao University of Science&TechnologyQingdao 266042China State Key Laboratory of Bio-fibers and Eco-textiles Qingdao UniversityQingdao 266071China

Macromolecule nanocrystal network and strong interfacial interaction are always beneficial to enhance the mechanical property of polymer-based ***(vinyl alcohol)(PVA),a typical biocompatible semicrystalline polymer,is an ideal candidate for preparing high performance polymer-based ***,the rich hydrogen bonds between PVA matrix and graphene oxide(GO)can disrupt the formation of PVA nanocrystal ***,it remains a great challenge to achieve both strong and tough PVA-GO ***,by introducing a novel Janus-like amphiphilic graphene oxide(JGO),both hydrogen bonding and interfacial crystallization have been constructed between JGO sheets and PVA *** from amphiphilic interfacial interaction and the enhanced crystal network,both PVA-JGO dried films and their swollen hydrogel films show superior mechanical properties than those of traditional PVA-GO ***-JGO dried films exhibit a 264%improvement of toughness at a JGO loading of 1 wt%.Meanwhile,the corresponding PVA-JGO swollen hydrogel films display simultaneous improvement of nearly 8 times increase of tensile strength and 20 times increase of toughness compared to traditional PVA-GO *** work indicates multiple interfacial interactions and macromolecule crystal networks can be concurrent in PVA nanocomposites by innovative modification of nanofillers,providing a new strategy to construct PVA nanocomposites with high strength and high *** integration of outstanding mechanical and swelling resistance properties on PVA-JGO nanocomposite films render their promising applications,such as packaging and toughening hydrogel materials.

关键词： Poly(vinyl alcohol) Janus-like graphene oxide Hydrogen-bonding interactions Interfacial crystallization Amphiphilicity