检索结果-南通市图书馆

Large-scale carambola-like V_(2)O_(5) nanoflowers arrays on microporous reed carbon as improved electrochemical performances lithium-ion batteries cathode

引用

Journal of Energy Chemistry 2020年第12期29卷 388-395页

作者： Hua Tan Xin zhi Yu kai Huang Jianxin Zhong Bingan Lu School of Physics and Optoelectronics Hunan Institute of Advanced Sensing and Information TechnologyXiangtan UniversityXiangtan 41U05HunanChina School of Physics and Electronics State Key Laboratory of Advanced Design and Manufacturing for Vehicle BodyHunan Provincial Key Laboratory of Multi-electron based Energy Storage DevicesHunan UniversityChangsha 410083HunanChina

To search for new cathode materials with high energy density of Lithium-ion batteries(LIBs) is one of the most challenging issues. Vanadium pentoxide(V2 O5) with high theoretical specific capacity is believed to be a promising candidate for the next generation cathode materials, yet still suffers from low lithium ion diffusion coefficient and poor electronic conductivity resulting in low cycling life and poor rate performances. Here, we report new large-scale carambola-like V2 O5 nanoflowers arrays anchored on microporous reed carbon as high performances LIBs cathode. Each individual pore space of the microporous reed carbon is like a hexagonal cylinder, and the area of each carbon wall is more than103 um2, which is favorable for the growth of V2 O5 nanostructure arrays. After hydrothermal, the largescale carambola-like V2 O5 nanoflowers arrays can directly grow on the surface of microporous *** to the novel composite structures, the V2 O5 nanoflowers arrays@microporous carbon stabilizes at273 mA h g^(-1) after 100 cycles at 0.2 C. When cycling at 1.0 C over 500 cycles, the capacity still maintains at 180 mAh g^(-1). The demonstrated approach in this work paves the way for the development of high rate capability and excellent cycling stability V2 O5-based cathode materials.

关键词： V_(2)O_(5) Cathode Reed carbon Microporous Lithium-ion batteries

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synergy of activating substrate and introducing C–H…O interaction to achieve Rh2(II)-catalyzed asymmetric cycloisomerization of 1,n-enynes

引用

Science China Chemistry 2020年第9期63卷 1230-1239页

作者： Rui Wu kai Chen Jun Ma zhi-Xiang Yu Shifa Zhu Key Lab of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China Beijing National Laboratory for Molecular Sciences(BNLMS) Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of ChemistryPeking UniversityBeijing 100871China

We report the first Rh2(II)-catalyzed asymmetric cycloisomerization of activated enynes to provide cyclopropane-fused tetrahydropyridines in good yields and excellent enantioselectivities under mild *** activated group,CHZ(Z is electronwithdrawing group(EWG)),in the enyne substrates exerts two synergetic roles,one is to activate alkyne for the cyclopropanation reaction;the other is to introduce the C–H…O interaction between substrate and catalyst(reducing the energy barrier of the reaction).This double-mode activation was supported by both density functional theory(DFT)calculations and experimental *** strategy was also extended to other CH2 Z(Z can be OH,OMe,F)as activating groups that made the CH2 more acidic so that the substrates could also form increased C–H…O interaction with the catalyst.

关键词： asymmetric cycloisomerization chiral cyclopropane dirhodium catalysis carbene

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Viscoplastic constitutive model of a nickel-based superalloy under multiaxial loading conditions

引用

Journal of Iron and Steel Research International 2021年第9期28卷 1190-1202页

作者： Wen-bin Jia Xin Li zhi Chen kai Zhao Lei Fang Key Laboratory of Aero-Engine Thermal Environment and Structure Ministry of Industry and Information TechnologyJiangsu Province Key Laboratory of Aerospace Power SystemState Key Laboratory of Mechanics and Control of Mechanical StructuresCollege of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing210016JiangsuChina

Based on Chaboche constitutive model,a viscoplastic constitutive model of nickel-based alloy under multiaxial loading is proposed by introducing Lemaitre damage model and non-proportional hardening *** damage model can characterize the effect of microscopic defects on the fatigue behavior and non-proportional hardening factor is used to describe non-proportional hardening ***,the stress–strain hysteresis loops at room and high temperatures under different loading conditions are simulated by the proposed constitutive *** between experiments and simulations confirms that the proposed model can reasonably predict the fatigue behavior of nickel-based alloy under different multiaxial *** last,the fatigue life predictions under different multiaxial loadings are investigated,and comparison between experiments and simulations verifies the accuracy of the proposed model.

关键词： Nickel-based alloy Multiaxial loading Viscoplastic constitutive model Lemaitre damage model Non-proportional hardening factor

来源：

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

A new era of mass data storage in artificial chromosome

引用

Science China(Life Sciences) 2022年第7期65卷 1477-1478页

作者： zhi Ping Huanming Yang Yue shen BGI-shenzhen Shenzhen 518083China Guangdong Provincial Key Laboratory of Genome Read and Write BGI-ShenzhenShenzhen 518120China George Church Institute of Regenesis BGI-ShenzhenShenzhen 518120China shenzhen Institute of Synthetic Biology Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Traditional silicon-based storage media will soon be unable to meet the exponentially increasing data archiving demands,and efforts must be made to find *** an ancient and efficient information carrier in living organisms,DNA has been believed to have great potential as a novel storage *** holds numerous advantages,such as remarkably high storage density,extremely long durability,and the costefficiency of information replication.

关键词： artificial durability holds

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Adaptive semi-empirical model for non-contact atomic force microscopy

引用

Chinese Physics B 2022年第8期31卷 682-687页

作者： Xi Chen Jun-kai Tong zhi-Xin Hu Center for Joint Quantum Studies and Department of Physics Institute of ScienceTianjin UniversityTianjin 300350China State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Non-contact atomic force microscope is a powerful tool to investigate the surface topography with atomic *** we propose a new approach to estimate the interaction between its tips and samples,which combines a semi-empirical model with density functional theory(DFT)*** generated frequency shift images are consistent with the experiment for mapping organic molecules using CuCO,Cu,CuCl,and CuO_(x)*** approach achieves accuracy close to DFT calculation with much lower computational cost.

关键词： semi-empirical model atomic force microscopy density functional theory functionalized tips

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Converting Thiophene in Simulated Coking Crude Benzene to N,N-Dimethyl-2-thiophenecarboxamide by Dimethylcarbamyl Chloride Under Mild Conditions

引用

Chemical Research in Chinese Universities 2019年第4期35卷 674-679页

作者： shen Xizhou SONG Hao FANG Liuya DENG Hang GAN Feng shen zhi School of Chemical Engineering & Pharmacy Wuhan Institute of Technology Wuhan 430205 P. R. China Key Laboratory for Green Chemical Process Ministry of Education Wuhan Institute of Technology Wuhan 430073 P. R. China

Since the content of thiophene in coking crude benzene is high, it is necessary to remove it from coking crude benzene for efficient utilization. In this study, an important intermediate, N,N-dimethyl-2-thiophenecarboxamide, was synthesized from thiophene and dimethylcarbamyl chloride. The influences of the dosages of dimethylcarbamyl chloride and ZnCl2 catalyst, reaction temperature and time on the removal rate were further explored based on the reaction *** structure of the target product was characterized by means of MS,NMR and 13C *** removal rate of thiophene was 98.14% after the reaction for 2 h and thiophene was almost removed after the reaction for 3 h under the optimal reaction conditions [a molar ratio of n(thiophene):n(dimethylcarbamyl chioride):w(ZnCl2)=1:12:10,300 r/min, 318 K and 101.325 kPa].The acylation of thiophene with dimethylcarbamyl chloride was approximately in accord with the first order kinetic equation at *** activation energy was 53.9850 kJ/mol and the pre-exponential factor was 1.4521×10^9 h^-1.

关键词： Coking crude benzene F-C acylation Acyl chloride Thiophene Thiophene derivative

来源：

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

Development of Transgenic Glyphosate-Resistant Rice with G6 Gene Encoding 5-Enolpyruvylshikimate-3-Phosphate Synthase

引用

Agricultural Sciences in China 2011年第9期10卷 1307-1312页

作者： ZHAO Te LIN Chao-yang shen zhi-cheng State Key Laboratory of Rice Biology and Institute of Insect Sciences Zhejiang University Hangzhou 310028 P.R. China

Glyphosate-resistant crops have been a huge economic success for genetic engineering. The creating of new glypbosateresistant plants would increase the available choices for planting and lower the price of genetically modified crop seeds. A novel G6 gene from Pseudomonas putida that encoded 5-enolpyruvylshikimate-3-phosphate synthase （EPSPS） was previously isolated. The G6 gene was transfected into rice via Agrobacterium-mediated transformation. The transgenic rice obtained was confirmed by PCR, Southern, and Western blots. The lab experiment and field trials further confirmed that the transgenic rice can survive glyphosate spraying at a dose of 8 g L^-1. In contrast, conventional rice was killed at a weed control glyphosate spray dose of 1 g L^-1. Altogether, the present study showed that the G6 gene works well in rice in vivo for glyphosate-resistance.

关键词： transgenic rice glyphosate-resistance EPSPS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A mathematical diffusion model of carbon isotopic reversals inside ultra-tight Longmaxi shale matrixes

引用

Petroleum Science 2022年第5期19卷 2014-2026页

作者： Bao-Jian shen zhi-Liang He Cheng Tao Jin-Cai shen Zong-Quan Hu zhi-Ming Li Yuan-Hao Cao Wei Chen State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development SINOPECBeijing100083China Wuxi Petroleum Geology Institute SINOPEC Petroleum Exploration and Production Research InstituteWuxiJiangsu 214126China China Petroleum&Chemical Corporation Beijing100728China Chongqing Fuling Shale Gas Exploration and Development Co. Ltd.SINOPECChongqing408014China Petroleum Exploration and Production Research Institute SINOPECBeijing100083China School of Energy Soochow UniversitySuzhouJiangsu 215006China

Developing mathematical models for high Knudsen number(Kn)flow for isotopic gas fractionation in tight sedimentary rocks is still *** this study,carbon isotopic reversals(δ^(13)C_(1)>δ^(13)C_(2))were found for four Longmaxi shale samples based on gas degassing *** in shale with higher gas content exhibits larger ***,a mathematical model was developed to simulate the carbon isotopic reversals of methane and *** model is based on these hypotheses:(i)diffusion flow is dominating during gas transport process;(ii)diffusion coefficients are nonlinear depending on concentration *** model not only shows a good agreement with isotopic reversals,but also well predicts gas production rates by selecting appropriate exponents m and m^(*) of gas pressure gradient,where m is for ^(12)C and m^(*)is for ^(13)***,the(m−m^(*))value has a positive correlation with fractionation level.(m1−m1^(*))of methane are much higher than that of ***,the predicted carbon isotopic reversal magnitude(δ^(13)C_(1)−δ^(13)C_(2))exhibits a positive relationship with total gas content since gas in shale with higher gas content experiences a more extensive high Kn number diffusion *** a result,our model demonstrates an impressive agreement with the experimental carbon isotopic reversal data.

关键词： Diffusion Isotopic fractionation Carbon isotopic reversal Modeling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Frequency domain decision feedback equalizer for time-reversal space-time block coding

引用

The Journal of China Universities of Posts and Telecommunications 2012年第1期19卷 38-43页

作者： DONG Chao LIN Jia-ru NIU kai HE zhi-qiang BIE zhi-song The Key Laboratory of Universal Wireless Communications Ministry of EducationBeijing University of Posts and TelecommunicationsBeijing 100876China

In this paper, a frequency domain decision feedback equalizer is proposed for single carrier transmission with time-reversal space-time block coding （TR-STBC）. It is shown that the diagonal decision feedback equalizer matrix can be calculated from the frequency domain channel response. Under the perfect feedback assumption, the proposed equalizer can approach matched filter bound （MFB）. Compared with the existing time domain decision feedback equalizer, the proposed equalizer exhibits better performance with the same equalization complexity.

关键词： decision feedback equalization matched filter bound time-reversal space-time block coding (TR-STBC)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Robust video denoising with sparse and dense noise modelings

引用

Science China(Information Sciences) 2018年第1期61卷 270-272页

作者： Guiping shen zhi HAN Xi'ai CHEN Yandong TANG State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of Sciences University of Chinese Academy of Sciences

Videos can be contaminated by noise even when captured by high-quality *** video data has both spatial and temporal redundancies,low rank factorization has been ***,most denoising methods relied on a single statistical distribution to model noise,such as Gaussian distribution[1,2].Ji et al.[3]proposed a low rank matrix completion(LRMC)relying on

关键词： Robust video denoising with sparse and dense noise modelings Figure

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：