检索结果-南通市图书馆

Planar Li growth on Li_(21)Si_(5)modified Li metal for the stabilization of anode

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第17期76卷 156-165页

作者： Liuyang Cao Xue Cheng Hongjie Xu Guoqin Cao junhua hu Guosheng Shao School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China State Center for International Cooperation on Designer Low-Carbon&1 Environmental Materials(CDLCEM) Zhengzhou UniversityZhengzhou 450001China Zhengzhou Materials Genome Institute(ZMGI) Xingyang 450100China Institute for Renewable Energy and Environmental Technologies University of BoltonBolton BL35ABUK

Lithium(Li)metal is widely considered the ultimate anode for future rechargeable batteries.However,dendritic growth and related parasitic reactions during long-term cycling often lead to severe safety hazards and catastrophic failure.Herein,we fabricate a hybrid anode by coating single-phase Li_(21)Si_(5)on lithium metal.The resultant electrodes show a stable cycle and depressed polarization in symmetric and half cells.A planar plating/stripping behavior is observed on the modified anode.The investigation of the interplay of Li and Li_(21)Si_(5)shows relatively large adsorption energy in the Li-Si system.The deposition and stripping are surface processes,and Li_(21)Si_(5)maintains its intrinsic phase structure.The deposited Li layer around Li_(21)Si_(5)also has the advantage of diminished preferred orientation,which also contributes to the planar growth of Li.Both LiFePO4(LFP)and LiNi1/3Co1/3 Mn1/3O2(NCM)cathodes were applied to further demonstrate the enhanced rate and cycle performance.

关键词： Lithium anode Planar growth Density functional theory Core-shell structure Adsorption energy

Variation and Sexual Dimorphism of Body Size in the Plateau Brown Frog along an Altitudinal Gradient

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2015年第4期6卷 291-297页

作者： Xueyun FENG Wei CHEN junhua hu Jianping JIANG Chengdu Institute of Biology Chinese Academy of Sciences University of Chinese Academy of Sciences Ecological Security and Protection Key Laboratory of Sichuan Province Mianyang Normal University

Variation in body size and sexual size dimorphism（SSD） can have important consequences for animal ecology, behavior, population dynamics and the evolution of life-history traits. Organisms are expected to be larger in colder climate（i.e., Bergmann＇s rule） and SSD varies with body size（i.e., Rensch＇s rule）. However, the underlying mechanisms are still elusive. The plateau brown frog（Rana kukunoris）, a medium-sized anuran species with femalebiased SSD, is endemic to the Qinghai-Tibetan Plateau（QTP）. From 1797 m（Maoxiang＇ping） to 3453 m（Heihe＇qiao） in the eastern margin of the QTP, we surveyed 10 populations of R. kukunoris and collected phalanges and snout vent length（SVL） data for 258 adult individuals（199 males versus 59 females）. Based on these data, we explored how body size and SSD varying along the altitudinal gradient and examined the corresponding effects of temperature. We found body size to be larger at higher altitude for males but not for females, with likely effects from the temperature on the variation in male body size. Sex differences in growth rates may be the main cause of the variation in SSD. Our results suggested that only males follow the Bergmann＇s rule and variation in SSD of R. kukunoris do not support the Rensch＇s rule and its inverse. Therefore, the variations of body size can be different between sexes and the applicability of both Bergmann＇s rule and Rensch＇s rule should depend on species and environment where they live.

关键词： Altitudinal gradient Bergmann＇s rule body size variation Qinghai-Tibetan Plateau Rana kukunoris,Rensch＇s rule sexual size dimorphism

Endemic Amphibians and Their Distribution in China

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2012年第2期3卷 163-171页

作者： junhua hu Cheng LI Feng XIE Jianping JIANG Chengdu Institute of Biology Chinese Academy of Sciences

Amphibians are good indicators of ecosystem health. Updating the information of endemic species in time and understanding their spatial distributions are necessary for the development of integrative conservation strategies and the elucidation of geographic patterns of amphibians. We analyzed the diversity and distributions of the endemic amphibians in China based on a database of specimen records, recently published literature, and field surveys. Two hundred and sixty two endemic species of amphibians, belonging to 59 genera in 12 families and two orders, are recognized. They account for 67% of the total number of amphibian species in China, with the family Megophryidae possessing the largest number of endemics. There are also 17 genera endemic to China. Across provinces, the species richness of endemics shows five levels with a hierarchical diversification. Sichuan has the largest number of endemics, while Heilongjiang and Jilin have no endemic species. Alternatively, whether on the level of endemic genus or species, the highest diversity occurs in the Western Mountains and Plateau Subregion. The distribution ranges of most endemic species cover ≤ 4 provinces or zoogeographic subregions. Additionally, the species richness of endemics along an elevational gradient shows a bell-shaped pattern with the peak around 800 m. Most endemic species are distributed in areas of low to mid elevation(c. 700–1 500 m), while 36 species are distributed up to 3 000 m. Endemic species richness decreases with increasing of elevation range. Species at mid elevations display large range sizes, while species at lower and higher elevations exhibit smaller ranges. Our results are to be beneficial for further exploration of the underlying mechanisms of distributional patterns of amphibians in China. This study highlights a need to promote conservation programs for Chinese endemic amphibians due to their narrow distribution ranges and potential threats.

关键词： amphibian diversity conservation distribution pattern elevational gradient endemic species

An aerosol formulation of R-salbutamol sulfate for pulmonary inhalation

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2014年第1期4卷 79-85页

作者： Xuemei Zhang Qing Liu junhua hu Ling Xu Wen Tan School of Bioscience and Bioengineering South China University of TechnologyGuangzhou 510006China Key-Pharma Biomedical Inc. Dongguan 523000China

An aerosol formulation containing 7.5 mg of R-salbutamol sulfate was developed.The aerosol was nebulized with an air-jet nebulizer,and further assessed according to the new European Medicines Agency(EMA)guidelines.A breath simulator was used for studies of delivery rate and total amount of the active ingredient at volume of 3 mL.A next generation impactor(NGI)with a cooler was used for analysis of the particle size and in vitro lung deposition rate of the active ingredient at 51C.The anti-asthmatic efficacy of the aerosol formulation was assessed in guinea pigs with asthma evoked by intravenous injection of histamine compared with racemic salbutamol.Our results show that this aerosol formulation of R-salbutamol sulfate met all the requirements of the new EMA guidelines for nebulizer.The efficacy of a half-dose of R-salbutamol equaled that of a normal dose of racemic salbutamol.

关键词： R-salbutamol Nebulizer NGI Particle size Dose uniformity Guinea pigs Asthma

Temporal variations in coda attenuation associated with the 2008 Wenchuan(M_(W)7.9)Earthquake in SW,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

Geodesy and Geodynamics 2021年第6期12卷 424-440页

作者： junhua hu Guoxin Zhang Liyun Fu Yan Zhang Songhui Li State Key Laboratory of Simulation and Regulation ofWater Cycle in River Basin China Institute ofWater Resources and Hydropower ResearchA-1 Fuxing RoadBeijing 100038China Department of Structures and Materials China Institute of Water Resources and Hydropower ResearchA-1 Fuxing RoadBeijing 100038China Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesNo.19Beitucheng Western RoadBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Innovation Academy for Earth Science Chinese Academy of SciencesNo.19Beitucheng Western RoadBeijing 100029China

In this study,waveform data obtained from Western Sichuan Seismic Array(WSSA)in China was utilized to reveal the temporal variations in coda attenuation around the eastern Tibet Plateau and Western Sichuan.Based on the single-scattering model,coda attenuation factor QC^(-1) is calculated in narrower overlapping frequency bands at 1.0-24 Hz by measuring the coda decay rates for local earthquakes before and after the Wenchuan mainshock.The temporal variations in coda attenuation are investigated within three periods.The periodⅠlasted from January 2007 to the end of 2007.The periodⅡlasted from January 2008 till Wenchuan earthquake.The periodⅢlasted from the mainshock to the end of 2008.The resulted temporal variations demonstrate an increase in average QC^(-1) by approximately 35%-45%in the vicinity of Longmenshan and 30%-35%in Sichuan Basin after the Wenchuan earthquake in lower frequency bands within 1.25-8 Hz.On the contrary,the average QC^(-1) is shown to decrease by approximately10%-18%in southern segment of Longmenshan,15%-38%in the Chuan-Dian block,and 10-12%in the South China block.These results are confirmed by a statistical t-test at 99.9%confidence level No statistically significant change in QC^(-1)(huan earthquake.

关键词： Wenchuan earthquake Single-scattering model Coda attenuation Tectonic static stress

Microhabitat Segregation of Parapatric Frogs in the Qinling Mountains

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2019年第1期10卷 48-55页

作者： Shengnan YANG Jianping JIANG Zhenhua LUO Xin YANG Xiaoyi WANG Wenbo LIAO junhua hu Chengdu Institute of Biology Chinese Academy of Sciences Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education) China West Normal University School of Life Sciences Central China Normal University

Coexistence mechanisms for species with similar ecological traits and overlapping geographic distributions are basic questions in ecology and evolutionary biology. Specific habitat requirements often limit distribution range as well as facilitate partitioning resource utilization in ecological similar species. Understanding niche segregation and differences in microhabitat utilization can contribute to identifying coexistence mechanisms between parapatric species. Feirana quadranus and F. taihangnica are two closely related frog species with parapatric geographic ranges and an elongated contact zone within the Qinling Mountains, which is an important watershed for East Asia. Here, we analysed the difference in microhabitat utilization between the two frog species and explored the key ecological factors that induced their microhabitat differentiation based on quadrats sampled in the contact zone. Our comparison of twenty environmental variables showed that both species used microhabitats with alkalescent warm water and gentle slope conditions. The principal component analysis indicated that climate-related variables, vegetation conditions, and river width were the important factors for microhabitat utilization of these species. These findings contribute to our understanding on the coexistence mechanisms of these two related and parapatric Asian mountain frog species. This study can also be helpful for identifying target habitats to conduct conservation actions and management strategies effectively in the face of environmental changes.

关键词： coexistence contact zone microhabitat utilization niche segregation Feirana Qinling Mountains

Carbon Nanosheets Encapsulated NiSb Nanoparticles as Advanced Anode Materials for Lithium-Ion Batteries

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2020年第2期3卷 186-191页

作者： Qichang Pan Yanan Wu Wentao Zhong Fenghua Zheng Youpeng Li Yanzhen Liu junhua hu Chenghao Yang Guangzhou Key Laboratory for Surface Chemistry of Energy Materials School of Environment and EnergyNew Energy Research InstituteSouth China University of TechnologyGuangzhou 510006China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China

Metallic antimony(Sb) has been attracted much attentions as anode for lithium-ion batteries due to its high capacity.Nevertheless,the large volume expansion during the lithiation process leads to poor electrochemical performance,which seriously limits the practical application in lithium-ion batteries.Herein,NiSb nanoparticles encapsulated by carbon nanosheets have been developed via a facile strategy and as anode for lithium-ion batteries.In this attractive structure,the carbon nanosheets can effectively avoid volume change of NiSb nanoparticles and inhibit the direct contact of NiSb nanoparticles to the electrolyte during the lithiation/delithiation process.As a result,the NiSb/C nanosheets display an outstanding long cycling performance(405 mA h g-1 after 1000 cycles at 1.0 A g-1) and excellent rate capability(305 mA h g-1 at 2.0 A g-1) when application in lithium-ion batteries.

关键词： anode carbon nanosheets lithium-ion batteries NiSb alloy

TB6钛合金模锻件低倍组织局部粗晶形成机理及预测

在线全文

学校读者我要写书评

暂无评论

机械工程学报 2024年第8期60卷 121-131页

作者：张禹森陈雷刘胜杰胡峻华张启飞崔明亮胡建良金淼燕山大学机械工程学院秦皇岛066004 中国第二重型机械集团德阳万航模锻有限责任公司德阳618013

经α+β两相区变形及退火后的TB6钛合金模锻件低倍组织局部区域显现出了粗晶缺陷。通过热模拟试验,结合微拉伸及扫描电镜(Scanning electron microscope,SEM)、背散射电子衍射仪(Electron black-scattered diffraction,EBSD)等微观分析... 详细信息

经α+β两相区变形及退火后的TB6钛合金模锻件低倍组织局部区域显现出了粗晶缺陷。通过热模拟试验,结合微拉伸及扫描电镜(Scanning electron microscope,SEM)、背散射电子衍射仪(Electron black-scattered diffraction,EBSD)等微观分析手段,分析对比低倍组织中粗、细晶区的显微特点及力学性能,探讨低倍粗晶形成机理,提出低倍粗晶显现的工艺判据并建立预测模型。结果表明,低倍粗晶主要分布在变形温度低且变形程度大的金属剧烈流动区域,与细晶材料相比,粗晶使得屈服强度降低,但伸长率和抗拉强度提高。经两相区加热后,锻件转运过程中表面温度降低,温降导致表面区域温度不均,在大变形速率下,表面圆弧区域软化程度差别较大,易发生部分动态再结晶,产生晶界角较大的动态再结晶晶粒(β相)。退火后,该动态再结晶晶粒通过晶界迁移实现对周边产生的晶界角较小的静态再结晶晶粒的吞并,形成粗晶。变形温度(T)越低,变形量越大且不超过临界值时,低倍粗晶越容易显现。建立T与fε间的量化关系;以fε为判据,通过二次开发建立有限元子程序,实现锻件低倍粗晶分布的可视化预测。

关键词： TB6钛合金低倍粗晶形成机理再结晶可视化模型

Nitrogen/sulphur dual-doped hierarchical carbonaceous fibers boosting potassium-ion storage

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第4期30卷 420-427页

作者： Junzhi Li Junming Cao Xifei Li junhua hu Yaohui Zhang Hirbod Maleki Kheimeh Sari Chunxiao Lv IgorVZatovsky Wei Han Sino-Russian International Joint Laboratory for Clean Energy and Energy Conversion Technology College of PhysicsJilin UniversityChangchun 130012JilinChina Xi'an Key Laboratory of New Energy Materials and Devices Institute of Advanced Electrochemical Energy&School of Materials Science and EngineeringXi’an University of TechnologyXi’an 710048ShaanxiChina State Center for International Cooperation on Designer Low-carbon&Environmental Materials(CDLCEM) Zhengzhou UniversityZhengzhou 450001HenanChina School of Physics Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Collaborative Innovation Center for Marine Biomass Fibers Materials and Textiles of Shandong ProvinceSchool of Environmental Science and EngineeringQingdao UniversityQingdao 266071ShandongChina International Center of Future Science Jilin UniversityChangchun 130012JilinChina

The carbon materials as anode electrodes have been widely studied for potassium ion batteries(PIBs).However,the large size of potassium ions prevents their intercalation/deintercalation,resulting in poor storage behaviors.Herein,a novel design of N/S codoped hierarchical carbonaceous fibers(NSHCF)formed from nanosheets self-assembled by catalyzing Aspergillus niger with Sn is reported.The asprepared NSHCF at 600℃(NSHCF-600)exhibits a high reversible capacity of 345.4 m Ah g^(-1) at 0.1 A g^(-1) after 100 cycles and an excellent rate performance of 124.5 m Ah g^(-1) at 2 A g^(-1).The excellent potassium storage performance can be ascribed to the N/S dual-doping,which enlarges interlayer spacing(0.404 nm)and introduces more defects.The larger interlayer spacing and higher pyridinic N active sites can promote K ions diffusion and storage.In addition,the ex situ transmission electron microscopy reveals the high reversibility of potassiation/depotassiation process and structural stability.

关键词： Carbonaceous fibers Large interlayer spacing Nitrogen/sulphur dual-doping Potassium-ion batteries