检索结果-南通市图书馆

Accurate studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of N_(2)molecule

引用

Science China(physics,Mechanics & Astronomy) 2005年第4期48卷 385-398页

作者： REN Weiyi1,2, SUN Weiguo1, HOU Shilin3 & FENG Hao4.1. Institute of physics, college of Chemical Engineering, sichuan university, chengdu 61.065, China 2. Institute of Theoretical physics, Xihua Normal university, Nanchong 637002, China 3. Department of physics, China Oceanography university, Qingdao 266003, China 4. college of physics, sichuan university, chengdu 61.065, China Institute of physics College of Chemical Engineering Sichuan University Chengdu China Institute of Theoretical physics Xihua Normal University Nanchong China Department of physics China Oceanography University Qingdao China college of physics Sichuan University Chengdu China

It is usually very difficult to directly obtain molecular dissociation energy De and all accurate high-lying vibrational energies for most diatomic electronic states using modern experimental techniques or quantum theories, and it is also very difficult to give accurate analytical expression for diatomic molecular dissociation energy. This study proposes a new analytical formula for obtaining accurate molecular dissociation energy based on the LeRoy and Bernstein’s energy expression in dissociation limit. A set of full vibrational energy spectra for some electronic states of N2 molecule are studied using the algebraic method (AM) suggested recently, and the corresponding accurate molecular dissociation energies are evaluated using the proposed new formula and high-lying AM vibrational energies. The results show that the AM spectra and the new theoretical dissociation energies agree excellently with experimental data, and thereby providing a new physical approach to generating accurate dissociation energies for electronic states of diatomic molecules.

关键词： vibrational energy, dissociation energy, nitrogen molecule, algebraic method.

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

Land Use of the Three Gorges Reservoir Area and the Effect on Its Landscape Pattern in the Recent 50 Years

引用

Wuhan university Journal of Natural Sciences 2006年第4期11卷 910-914页

作者： HUANG Zhiqin 1,2,3 , ZHOU Wancun 1 ,ZHOU Jieming 4., ZHU Mingcang 3,5 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences , chengdu 61004., sichuan, China 2. Graduate university of Chinese Academy of Sciences, Beijing 10004., China 3. sichuan Institute of Land Resource Management, chengdu 61004., sichuan , China 4. Department of Resources and Environment Science, sichuan Normal university , chengdu 610061, sichuan, China 5. college of Information Engineering, chengdu university of Technology, chengdu 610059, sichuan, China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu Sichuan China Graduate university of Chinese Academy of Sciences Beijing China sichuan Institute of Land Resource Management Chengdu Sichuan China Department of Resources and Environment Science Sichuan Normal University Chengdu Sichuan China college of Information Engineering Chengdu University of Technology Chengdu Sichuan China

The paper makes detailed analysis on the changing processes of the main types of land use in Three Gorges Reservoir Area through the techniques of RS （Remote Sense） and GIS （Geography Information System）. Based on the theory of landscape ecology, many types of landscape pattern indexes are calculated and made correlation analysis. The results indicate that： in 1995 the ecological environment of Three Gorges Reservoir Area was the most vulnerable in the recent 50 years, but resumed in 2002; the landscape pattern diversity index, fractal dimension index and fragmentation index has close correlation with the area of land use/cover change （LUCC）. The research also releases that the increase of the cultivated land, grassland and construction land deteriorates the landscape ecological pattern, while the increase of forest land area will help restore the landscape ecological pattern to its original state. The rapid change of grassland is an important index of the change of landscape pattern, because it has the most effect on change of landscape pattern index.

关键词： the Three Gorges Reservoir Area land use/cover change landscape pattern.

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

Constructing globally consecutive 3D conductive network using P-doped biochar cotton fiber for superior performance of silicon-based anodes

引用

Journal of Materials Science & Technology 2024年第6期173卷 181-191页

作者： Jun Cao Jianhong Gao Kun Wang Zhuoying Wu Xinxin Zhu Han Li Min Ling chengdu Liang Jun Chen Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China Institute of Zhejiang university-Quzhou Zheda Road 99Quzhou 324000China

The inferior conductivity and drastic volume expansion of silicon still remain the bottleneck in achieving high energy density Lithium-ion Batteries(LIBs).The design of the three-dimensional structure of electrodes by compositing silicon and carbon materials has been employed to tackle the above challenges,however,the exorbitant costs and the uncertainty of the conductive structure persist,leaving ample room for ***,silicon nanoparticles were innovatively composited with eco-friendly biochar sourced from cotton to fabricate a 3D globally consecutive conductive *** network serves a dual purpose:enhancing overall electrode conductivity and serving as a scaffold to maintain electrode *** conductivity of the network was further augmented by introducing P-doping at the optimum doping temperature of 350℃.Unlike the local conductive sites formed by the mere mixing of silicon and conductive agents,the consecutive network can affirm the improvement of the conductivity at a macro ***,first-principle calculations further validated that the rapid diffusion of Li^(+)is attributed to the tailored electronic microstructure and charge rearrangement of the *** prepared consecutive conductive Si@P-doped carbonized cotton fiber anode outperforms the inconsecutive Si@Graphite anode in both cycling performance(capacity retention of 1777.15 mAh g^(-1) vs.682.56 mAh g^(-1) after 150 cycles at 0.3 C)and rate performance(124..24.mAh g^(-1) vs.370.28 mAh g^(-1) at 2.0 C).The findings of this study may open up new avenues for the development of globally interconnected conductive networks in Si-based anodes,thereby enabling the fabrication of high-performance LIBs.

关键词： 3D conductive network Biochar carbon-silicon anode Heteroatoms doping strategy DFT calculation Lithium-ion battery

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

Design and Expression of a Synthetic phyC Gene Encoding the Neutral Phytase in Pichia pastoris

引用

Acta Biochimica et Biophysica Sinica 2006年第11期38卷 803-811页

作者： Li-Kou ZOU~(1,3) Hong-Ning WANG~(2,1*) Xin PAN~4.Tao XIE~1 Qi WU~5 Zi-Wen XIE~1 Wan-Rong ZHOU~1 1 Laboratory of Veterinary and Biotechnology,sichuan Agricultural university,Ya'an 625014.China 2 sichuan university Bioengineering Research Center for Animal Disease Prevention and Control,chengdu {4.,China 3 Faculty of Environment and Resource of Dujiangyan Campus,sichuan Agricultural university,Dujiangyan 611830,China 4.college of Earth Science,Chengd university of Technology,chengdu 610059,China 5 college of Life Science,sichuan Agricultural university,Ya'an 625014.China Laboratory of Veterinary and Biotechnology Sichuan Agricultural UniversityYa'an 625014 China Faculty of Environment and Resource of Dujiangyan Campus Sichuan Agricultural UniversityDujiangyan 611830 China sichuan university Bioengineering Research Center for Animal Disease Prevention and Control Chengdu 610065 China college of Earth Science Chengdu University of TechnologyChengdu 610059 China college of Life Science Sichuan Agricultural UniversityYa'an 625014 China

The 1074.bp phyCs gene （optimized phyC gene） encoding neutral phytase was designed andsynthesized according to the methylotrophic yeast Pichia pastoris codon usage bias without altering theprotein *** expression vector,pP9K-phyCs,was linearized and transformed in *** of total extracellular phytase activity was 17.6 U/ml induced in Buffered Methanol-complex Medium（BMMY） and 18.5 U/ml in Wheat Bran Extract Induction （WBEI） medium at the flask scale,respectively,improving over 90 folds compared with the wild-type *** enzyme showed temperature optimumof 70℃ and pH optimum of *** enzyme activity retained 97% of the relative activity afterincubation at 80℃ for 5 *** of the heavy glycosylation the expressed phytase had a molecularsize of approximately 51 *** deglycosylation by endoglycosylase H （EndoH_f）,the enzyme had anapparent molecular size of 4. *** property and thermostability was affected by the glycosylation.

关键词： design expression synthetic phyC gene neutral phytase Pichia pastoris

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

Diffusion Equation on Fractals:Three-Dimensional Case

引用

Communications in Nonlinear Science and Numerical Simulation 1999年第3期4卷 3-5页

作者： Qiuhua ZENG and Houqiang LI(Department of physics, sichuan university, chengdu 610064. China) Department of physics Sichuan University ChengDu 610064 China

IntroductionInrecentyearsthephenomenonofunusualtrajnsport-prop***onindisorderedmediaorfractalmedia,anomalousdiffusionistheoretic... 详细信息

IntroductionInrecentyearsthephenomenonofunusualtrajnsport-prop***onindisorderedmediaorfractalmedia,anomalousdiffusionistheoretic...

关键词： comb model probability density diffusion on fractals

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

Role of gallium wetting layer in high-quality ZnO growth on sapphire (0001) substrates

引用

Science China(physics,Mechanics & Astronomy) 2004年第5期47卷 612-620页

作者： ZENG Zhaoquan1,3, WANG Yong2, DU Xiaolong1, MEI Zengxia1, KONG Xianghe3, JIA Jinfeng1, XUE Qikun1 & ZHANG Ze2, 4.1. State Key Laboratory for Surface physics, Institute of physics, Chinese Academy of Sciences, Beijing 100080, China 2. Laboratory of Electron Microscopy, Institute of physics, Chinese Academy of Sciences, Beijing 100080, China 3. college of physics and Engineering, Qufu Normal university, Qufu 273165, China 4. Beijing university of Technology, Beijing 100022, China State Key Laboratory for Surface physics Institute of Physics Chinese Academy of Sciences Beijing China college of physics and Engineering Qufu Normal University Qufu China Laboratory of Electron Microscopy Institute of Physics Chinese Academy of Sciences Beijing China Beijing university of Technology Beijing China

A Ga wetting layer was used to modify the surface structure of sapphire (0001) substrate to prepare high-quality ZnO film by radio frequency plasma-assisted molecule beam epitaxy. We found that this Ga layer plays a crucial role in eliminating 30 rotation domains, controlling polarity and decreasing defect density in ZnO epilayers, as demonstrated by in situ reflection high energy electron diffraction, ex situ high resolution X-ray diffraction and high resolution cross-sectional transmission electron microscopy. Zn-polar film of ZnO was determined by convergent beam electron diffraction. A Ga bilayer model is proposed to understand the effects of the Ga wetting layer on high-quality ZnO growth.

关键词： Ga wetting layer, sapphire, polarity, defect density, zinc oxide, rf-MBE, RHEED, HRXRD, TEM, CBED.

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

Anomalous Fractional Diffusion Equation forTransport Phenomena

引用

Communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 99-104页

作者： Qiuhua ZENG Houqiang LI De LIU(Department of physics, sichuan university, chengdu 610064. China) Department of physics Sichuan University ChengDu 610064 China

We derive the standard diffusion equation from the continuity equationand by discussing the defectiveness of earlier proposed equations, we get the generalizedfractional diffusion equation for anomalous diffusion.

关键词： fractal lattice probability density fractal anomalous diffusion

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

Electron microscopy study of the sakhaite from endogenous borate deposit in Hunan, China

引用

Science China Earth Sciences 2004年第3期47卷 232-238页

作者： LIU Xiangwen1,2, YANG Guangming2, ZOU Huamin3, QU Jing1 & ZHAO Wenxia4.1. Graduate School, China university of Geosciences, Wuhan 4.0074. China 2. Test Center, China university of Geosciences, Wuhan 4.0074. China 3. physics and Technology college, Wuhan university, Wuhan 4.0072, China 4. Test Center, Zhongshan university, Guangzhou 510275, China Graduate School China University of Geosciences Wuhan 430074 China Test Center China University of Geosciences Wuhan 430074 China physics and Technology college Wuhan University Wuhan 430072 China Test Center Zhongshan University Guangzhou 510275 China

Sakhaite specimens from an endogenous borate deposit in Hunan Province, China have been studied in detail by means of transmission electron microscopy (TEM). The selected area electron diffraction (SAED) patterns obtained with different crystal zone axes show that the crystal system is cubic, with a = 1.4.3 nm. The convergent beam electron diffraction (CBED) patterns indicate that the point group and space group of sakhaite is m3m and Fd3m, respec-tively. The space group of synthetic sakhaite determined by Chichagov (1974. is F4.32. The possible reasons why the space groups of the natural and the synthetic sakhaites are different are discussed.

关键词： sakhaite, space group, convergent beam electron diffraction (CBED).

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

Preliminary results of the study on wind erosion in the Qinghai-Tibetan Plateau using 137Cs technique

引用

Chinese Science Bulletin 2000年第11期45卷 1019-1025页

作者： YAN Ping, DONG Guangrong, ZHANG Xinbao & ZHANG Yiyun1. Key Laboratory of Environmental Change and Natural Disaster, the Ministry of Education of China, Beijing Normal university, Beijing 100875, China 2. Institute of Desert Research, Chinese Academy of Sciences, Lanzhou 730000, China 3. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, chengdu 61004., China 4. Department of physics, sichuan Union university, chengdu 61004., China Key Laboratory of Environmental Change and Natural Disaster the Ministry of Education of China Beijing Normal University Beijing China Institute of Desert Research Chinese Academy of Sciences Lanzhou China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Department of physics Sichuan Union University Chengdu China

The worldwide fallout of caesium-137 (137Cs) associated with the nuclear weapon tests during the 1950s and 1960s has provided a valuable man-made tracer for studies of soil erosion and sediment delivery. But relatively few researchers have used it to estimate wind erosion. In this note, the 137Cs technique is introduced into the studies of wind erosion and its modern processes inthe Qinghai-Tibetan Plateau. Two 137Cs reference inventories of 982.11 and 2 376.04.Bq · m-2 wereestablished preminarily, distributed in the south and middle-north parts of the studied arearespectively. By analyzing the patterns of 137Cs depth profiles from sampling sites, the aeolianprocesses of erosion and deposition in nearly 4. years have been revealed, i.e. the shrub coppicedunes (S1) and semi-fixed dunefields (S3) experienced the alternation of erosion and deposition,while the grasslands (S4. S6 and S7) and dry farmlands (S5) suffered erosion only. By using 137Csmodel, the average wind erosion rates for shrub coppice

关键词： 137Cs technique Qinghai-Tibetan Plateau wind erosion.

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

Nonequilibrium solvation theory:Comparison,modification and application

引用

Chinese Science Bulletin 2003年第10期48卷 965-970页

作者： FU Kexiang1,2, LI Xiangyuan1 & ZHU Quan1 1. college of Chemical Engineering, sichuan university, chengdu 61.065, China 2. college of {4., sichuan university, chengdu 61.065, China college of Chemical Engineering Sichuan University Chengdu 610065 China college of physics Sichuan University Chengdu 610065 China

Faults existing in the current theories of non- equilibrium solvation have been clarified in this report. Based on a novel expression of solvation free energy for nonequilibrium, generalized formulations of solvent reor- ganization energy for electron transfer and of solvation shift for spectrum have been established. Furthermore, a new form of solvent reorganization energy for electron transfer in two-sphere case, which greatly differs from the one by Mar- cus, has been deduced. A single-sphere model for solvation shift of spectrum has been put forward both by deducing the generalized formulations and by showing the correct forms of self-energy of reaction field. It has been concluded that the current theories overestimate the solvent reorganization energy and the solvation shift by a factor of about 2. By apply- ing the models established, the discrepancies between the theory and experiments before have been perfectly explained.

关键词：非平衡溶剂理论修正应用电子转移溶剂重构能量反应场溶剂交换

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

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：