检索结果-南通市图书馆

Quantum Charge Transfer in Quasi-One-Dimensional Mixed Halide Compounds

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 Physics Letters 1998年第10期15卷 737-738页

作者： WEI Jian-hua LIU De-sheng xie shi-jie MEI Liang-mo Department of Physics Shandong UniversityJinan 250100

Intrinsic charge transfer in mixed halide compounds PtX_(x)X'_(1-x ) was studied in the framework of the two-band extended Pielerls-Hubbard *** was found that the number of transferred charges can be a fraction times of the electronic *** maximum amount of the transferred charges will occur at a certain proportion x for a given mixed compound.

关键词： compound. model. charges

Influence of Heat-setting Temperature on the Microporous Structure and Properties of PP/HDPE Bilayer Microporous Membranes

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 2024年第8期42卷 1243-1252页

作者： jie xie Yong-shi Wu Jia-Yi xie Rui-jie Xu Cai-Hong Lei Sai-Nan Song Guang-Quan Li An-Ping Huang School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China Lanzhou Petrochemical Research Center Petrochemical Research InsititutePetroChinaLanzhou 730060China School of Chemistry and Civil Engineering Shaoguan CollegeShaoguan 512005China

Due to the mechanical stability of PP layer,the PP/HDPE double-layer microporous mem brane could be prepared at a higher heat-setting temperatu re than that of PE monolayer *** this work,the effects of heat-setting temperature on the pore structure and properties of PP/HDPE dou ble-layer membrane were *** the increase of heat-setting temperature from 120℃to 130℃,the length of connecting bridge crystal and crystallinity in the PE layer increase due to the melting of thin lamellae and the stability of connecting bridge structure during *** corresponding air permeability,po rosity,wetta bility of liquid electrolyte and mechanical property of the heat-set microporous membrane increase,exhibiting better electrochemical ***,when the heat-setting temperature is further increased to 140℃,higher than the melting point of PE resin,some pores are closed since the lamellae and connecting bridges melt and shrink during heat-setting,resulting in a decrease of air permeability and *** contrast,there is negligible change in the PP layer within the above heat-setting temperature *** study successfully builds the relationship between the stable pore structure and property of microporous membrane during heat-setting,which is helpful to guide the production of high-pe rformance PP/PE/PP lithium batteries separator.

关键词： PP/HDPE bilayer microporous membranes Heat-setting temperature SAXS

在线全文

学校读者我要写书评

暂无评论

基态非简并导电聚合物--坐标空间研究

物理学报 2009年第1期58卷 459-464页

作者：史晶高琨雷杰解士杰山东大学物理学院济南250100 济南铁道职业技术学院济南250013

通过引入简并破缺项,建立了非等势垒Kronig-Penney方势阱模型,在实坐标空间中研究了基态非简并聚合物——顺式聚乙炔的基态及其激发态,并与紧束缚模型所得到的结果进行了比较.给出了体系的电子态、电荷密度等在实坐标空间的分布特征.发... 详细信息

通过引入简并破缺项,建立了非等势垒Kronig-Penney方势阱模型,在实坐标空间中研究了基态非简并聚合物——顺式聚乙炔的基态及其激发态,并与紧束缚模型所得到的结果进行了比较.给出了体系的电子态、电荷密度等在实坐标空间的分布特征.发现在坐标空间研究可以更加准确地反映体系的电子态密度、电子空间密度分布等特征.

关键词：聚合物方势阱基态极化子

Electronic States in Quasi-one-Dimensional Copolymeric Sandwich Structures

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2001年第12期18卷 1644-1647页

作者： LIU De-Sheng WANG Lu-Xia WEI Jian-Hua ZHENG Bin xie shi-jie HAN Sheng-Hao MEI Liang-Mo School of Physics and Microelectronics Shandong UniversityJi'nan 250100 Department of Physics Jining Normal UniversityJining 272025 National Key Laboratory of Crystal Materials Shandong UniversityJi'nan 250100

The electronic properties of xPA/nPPP/yPA sandwiched copolymers with a well-barrier-well structure have been studied by using a tight-binding calculation. It was found that the electronic properties of the neutral states of these sandwiched copolymers are sensitive to the constitutions of PPP and PA monomers and the interface coupling between PA and PPP. It is verified that the quantum tunnelling effect will occur at the lowest conductive state of xPA/nPPP/xPA copolymers.

关键词： calculation sandwich Copolymer

Robust AUC maximization for classification with pairwise confidence comparisons

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第4期18卷 73-83页

作者： Haochen shi Mingkun xie Shengjun HUANG College of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China MIIT Key Laboratory of Pattern Analysis and Machine Intelligence Nanjing 211106China

Supervised learning often requires a large number of labeled examples,which has become a critical bottleneck in the case that manual annotating the class labels is *** mitigate this issue,a new framework called pairwise comparison(Pcomp)classification is proposed to allow training examples only weakly annotated with pairwise comparison,i.e.,which one of two examples is more likely to be *** previous study solves Pcomp problems by minimizing the classification error,which may lead to less robust model due to its sensitivity to class *** this paper,we propose a robust learning framework for Pcomp data along with a pairwise surrogate loss called *** provides an unbiased estimator to equivalently maximize AUC without accessing the precise class ***,we prove the consistency with respect to AUC and further provide the estimation error bound for the proposed *** studies on multiple datasets validate the effectiveness of the proposed method.

关键词： method pairwise weakly

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

有机半导体中极化子运动的同位素效应

物理学报 2020年第24期69卷 221-227页

作者：刘璇高腾解士杰山东大学物理学院晶体材料国家重点实验室济南250100

针对近年来实验发现的有机半导体电磁光现象中的同位素效应,基于强电声耦合的紧束缚模型,利用非绝热近似分别研究了小分子晶体和聚合物链内的极化子的运动,并通过引入有效质量,解释了同种材料中迁移率与基团质量的关系.结果表明氢元素... 详细信息

针对近年来实验发现的有机半导体电磁光现象中的同位素效应,基于强电声耦合的紧束缚模型,利用非绝热近似分别研究了小分子晶体和聚合物链内的极化子的运动,并通过引入有效质量,解释了同种材料中迁移率与基团质量的关系.结果表明氢元素的氘化或碳13元素的存在都会降低有机材料迁移率,且同位素效应的大小与电声耦合的大小有关.在同位素取代浓度不变时,同位素的分布不影响整个器件的迁移率.本文讨论了各种可能的同位素效应并对其物理机理进行了分析,为利用同位素效应调控有机器件性能提供理论支持.

关键词：同位素效应有机小分子晶体紧束缚模型

Pore structure and oxygen content design of amorphous carbon toward a durable anode for potassium/sodium-ion batteries

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第9期6卷 184-194页

作者： Xiaodong shi Chuancong Zhou Yuxin Gao Jinlin Yang Yu xie Suyang Feng jie Zhang Jing Li Xinlong Tian Hui Zhang State Key Laboratory of Marine Resource Utilization in South China Sea School of Marine Science and EngineeringSchool of Chemistry and Chemical EngineeringHainan UniversityHaikouChina School of Materials Science and Engineering Central South UniversityChangshaChina Key Laboratory of Advanced Energy Materials Chemistry Nankai UniversityTianjinChina Hainan Center for Drug and Medical Device Evaluation and Service HaikouChina

Both sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)are considered as promising candidates in grid-level energy storage ***,the larger ionic radii of K+and Na+induce poor diffusion kinetics and cycling stability of carbon anode *** structure regulation is an ideal strategy to promote the diffusion kinetics and cyclic stability of carbon materials by facilitating electrolyte infiltration,increasing the transport channels,and alleviating the volume ***,traditional pore-forming agent-assisted methods considerably increase the difficulty of synthesis and limit practical applications of porous carbon ***,porous carbon materials(Ca-PC/Na-PC/K-PC)with different pore structures have been prepared with gluconates as the precursors,and the amorphous structure,abundant micropores,and oxygen-doping active sites endow the Ca-PC anode with excellent potassium and sodium storage *** PIBs,the capacitive contribution ratio of Ca-PC is 82%at 5.0 mV s^(-1) due to the introduction of micropores and high oxygen-doping content,while a high reversible capacity of 121.4 mAh g^(-1) can be reached at 5 A g^(-1) after 2000 *** SIBs,stable sodium storage capacity of 101.4 mAh g^(-1) can be achieved at 2 A g^(-1) after 8000 cycles with a very low decay rate of 0.65%for per *** work may provide an avenue for the application of porous carbon materials in the energy storage field.

关键词： oxygen doping pore structure porous carbon potassium-ion batteries sodium-ion batteries

De novo Synthesis of Chiral 3,4-Dihydroquinazolines via One-Pot Enantioselective Ugi-Azide/Cyclization Sequences

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 Chemistry 2024年第18期42卷 2140-2146页

作者： Zu-Kui xie Jun-Jun Ding Yi-Ming Ou Jun-Xiu shi Meng-Lan Shen Chuan-Zhi Yao Hua-jie Jiang jie Yu Department of Applied Chemistry Anhui Province Engineering Laboratory for Green Pesticide Development and Applicationand Anhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Agricultural UniversityHefeiAnhui 230036China

Background and Originality Content,3,4-Dihydroquinazoline frameworks have frequently been encountered in natural products and bioactive *** the past decades,these key structures prompted the development of creative pharmaceuticals owing to their prominent biological properties,including trypanothione reductase(TryR)inhibitor,Hepatitis B virus(HBV)inhibitive activities,anticancer activities,etc.(Scheme 1A).[1]Notably,the chirality of the C4 atom is crucial for drug *** example,the DPC-083 is a potent reverse transcriptase inhibitor for the treatment of HIV infection but the undesired enantiomers exhibit virtually no activity.[ia]Therefore,developing synthetic methods for innovative chiral 4-substituted 3,4-dihydroquinazolines is significant and essential for drug discovery.

关键词： Anionic stereogenic-at-cobalt(ll)complex De novo synthesis post-Ugi transformation One-pot sequence Asymmetric synthesis Multicomponentreactions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

南京市大比例尺地形图的动态更新和维护研究

测绘通报 2008年第1期 46-49页

作者：谢士杰南京市规划局测绘信息处江苏南京210029

城市规划需要现势性强的全覆盖的城市大比例尺地形图,城市规划、建设导致地形图的快速变化。如何处理这一对矛盾,最大程度地实现测绘对城市规划、建设和管理的保障,是一个难题。将测绘与规划管理的日常业务进行结合,提出一整套城市大比... 详细信息

城市规划需要现势性强的全覆盖的城市大比例尺地形图,城市规划、建设导致地形图的快速变化。如何处理这一对矛盾,最大程度地实现测绘对城市规划、建设和管理的保障,是一个难题。将测绘与规划管理的日常业务进行结合,提出一整套城市大比例尺地形图的动态更新和维护的方法,制定相应的数据标准和规范,研制了支撑平台,并在浦口区进行实践,具有较强的可操作性。

关键词：动态更新基础地形图规划管理