检索结果-南通市图书馆

Theoretical Studies on Electronic Structures and Spectroscopy of Fluorescent Arylamino Fumaronitrile

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2008年第2期21卷 105-110页

作者： Xiao-peng Chen Yu-qi ding qi-wen Teng Department of Chemistry Zhejiang University Hangzhou 310027 China

A new series of fluorescent arylamino fumarinitrile derivatives was designed and optimized using density function theory at the B3LYP/6-31G^＊ level. Based on the optimized geometries, the electronic, fluorescent and 13C NMR spectra are calculated with INDO/CIS, CIS-ZINDO TD, and B3LYP/6-31G^＊ methods, respectively. Starting with the first of the series, the LUMO-HOMO energy gaps of the derivatives become wider and the fluorescent wavelengths and the main peaks in the electronic spectra are blue-shifted owing to the large steric effect of naphthyl rings. On the contrary, the energy gaps of the derivatives turn narrow, and the fluorescent wavelengths and the main peaks in the electronic spectra are red-shifted since hydroxyl groups improve the symmetry and extend the conjugation system. The chemical shifts of sp^2-C on the phenyl rings are moved upfield, while chemical shifts of carbon atoms on the cyano groups and those connected with the cyano groups are changed downfield in the presence of hydroxyl groups.

关键词： Arylamino fumaronitrile Fluorescence Energy gap B3LYP/6-31G^*

Boundary Regularity for Minimal Graphs of Higher Codimensions

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 Annals of Mathematics,Series B 2022年第5期43卷 869-876页

作者： qi ding Yuanlong XIN Shanghai Center for Mathematical Sciences Fudan UniversityShanghai 200438China Institute of Mathematics Fudan UniversityShanghai 200433China

In this paper,the authors derive H¨older gradient estimates for graphic functions of minimal graphs of arbitrary codimensions over bounded open sets of Euclidean space under some suitable conditions.

关键词： Boundary regularity Minimal graphs Higher condimension Bernstein type theorem

A SUPERONVERGENCE ANALYISIS FOR FINITE ELEMENT SOLUTION BY THE INTERPOLANT POSTPROCESSING ON IRREGULAR MESHES FOR SMOOTH PROBLEM

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2001年第3期19卷 323-326页

作者： qi-ding Zhu Qun Lin Institute of Science Hunan Normal UniversityChangsha 410081China Institute of System Academy of Mathematics and Systems SciencesChinese Academy of SciencesBeijing 100080China

The post-processing procedure is given by a interpolant postprocessing of the finit element solution by appropriately-define finite dimensional subspaces, The corresponding superconvergence are established on general ... 详细信息

关键词： finite element superconvergence interpolant postprocessing

Ecological footprint and vulnerability of marine capture fisheries in China

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2020年第4期39卷 100-109页

作者： qi ding Xiujuan Shan Xianshi Jin Key Laboratory of Sustainable Development of Marine Fisheries Ministry of Agriculture and Rural Affairs/Shandong Provincial Key Laboratory of Fishery Resources and Ecological EnvironmentYellow Sea Fisheries Research InstituteChinese Academy of Fishery SciencesQingdao 266071China Function Laboratory for Marine Fisheries Science and Food Production Processes Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China

China(herein referred as China’s mainland,and excluding Hong Kong,Macao and Taiwan)ranks as the world’s leading fishing nation,with approximately 11.1 million tons of domestic marine catch acquired in *** fisheries resources in China are mainly exploited by its 11 coastal provinces and municipalities,and the development of fishing industry varies among ***,few studies have examined the exploitation history of the 11 coastal provinces and *** this paper,we systematically quantified the exploitation history of marine fishery resources in China and then measured the vulnerability of the 11 coastal provinces and municipalities of China to a reduction in marine *** analysis suggested that Chinese marine fisheries experienced rapid growth from the mid-1980 s to the end of the 20 th century,and this rapid increase in marine catches were mainly promoted by increased fishing *** total primary production required level amounted to approximately 80%of the average primary productivity in 2017,and Zhejiang,Fujian,Shandong,Hainan and Guangdong provinces were the main fishing provinces in *** assessing three dimensions of vulnerability(exposure,sensitivity and adaptive capacity)to the impacts of a reduction in marine catches in the 11 coastal provinces and municipalities,we found that Hainan,Guangxi,Zhejiang and Fujian provinces had high or very high vulnerability,while the municipalities of Shanghai and Tianjin had low *** suitable adaptation policies and management plans based on the differences in vulnerability among coastal provinces is important in sustainable fisheries management.

关键词： marine capture fisheries coastal provinces and municipalities exploitation history vulnerability

Local pointwise convergence of the 3D finite element

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2023年第2期38卷 210-222页

作者： LIU Jing-hong ZHU qi-ding College of Science Guangdong University of Petrochemical TechnologyMaoming 525000China School of Mathematics and Statistics Hunan Normal UniversityChangsha 410081China

For an elliptic problem with variable coefficients in three dimensions,this article discusses local pointwise convergence of the three-dimensional(3D)finite ***,the Green's function and the derivative Green's function are ***,some relationship of norms such as L^(2)-norms,W^(1,∞)-norms,and negative-norms in locally smooth subsets of the domainΩis ***,local pointwise convergence properties of the finite element approximation are obtained.

关键词： nite element local convergence Green's function

Based on point merge for paired approach sequencing on closely spaced parallel runways

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2023年第5期10卷 934-946页

作者： Laijun Wang qi ding Dongxuan Wei College of Transportation Engineering Chang'an UniversityXi'an 710064China

The paired approach is a kind of efficiency approach to closely spaced parallel runways(CSPRs),and the point merge system has the powerful interval management function,which is effective to realize the converge of traffic flows from different approach *** order to improve the operation efficiency of the airport terminal area,a model of paired approach sequencing based on point merge is proposed to investigate the problem of increasing the operation capacity of the closely spaced parallel *** the minimum average flight delay time as the objective,the flight distance on sequencing legs,wake turbulence separation and paired approach safety separation as constraints,the genetic algorithm is used to optimize the paired approach sequencing of arrival *** the closely parallel runways of Shanghai Hongqiao International Airport run south as an example,the point merge program is designed and the effect of model was *** results show that after optimization,the average delay time and average landing time are reduced by 40.6%and 51.8%respectively,the capacity of the closely spaced parallel runways are 1.1 times higher than the actual,the flight uptime rate can reach 100%.It is concluded that the proposed model is feasible,which can effectively reduce delay times and alleviate congestion in terminal areas.

关键词： Air traffic management Sequence of arrival flights Point merge Closely spaced parallel runway Paired approach Genetic algorithm

Arbitrariness of the general solution of the partial differential equations and its applications

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2010年第7期53卷 1729-1739页

作者： ding qi Zhang Hongqing Dalian Univ Technol Sch Math Sci Dalian 116024 Peoples R China

Using the framework of formal theory of partial differential equations, we consider a method of computation of the bi-Hilbert polynomial (i.e. Hilbert polynomial in two variables). Furthermore, present an approach to compute the number of arbitrary functions of positive differential order in the general solution. Then, under the "AC=BD" model for mathematics mechanization developed by Hong-qing ZHANG, we present a method to reduce an overdetermined system to a well-determined one. As applications, the Maxwell equations and weakly overdetermined equations are considered.

关键词： 'AC=BD' model involution Hilbert polynomial arbitrariness overdetermined

A Parallel Finite Element Algorithm for the Unsteady Oseen Equations

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2021年第6期13卷 1501-1519页

作者： qi ding Yueqiang Shang School of Mathematics and Statistics Southwest UniversityChongqing 400715China Tongnan Middle School Chongqing 402660China

Based on fully overlapping domain decomposition,a parallel finite element algorithm for the unsteady Oseen equations is proposed and *** this algorithm,each processor independently computes a finite element approximate solution in its own subdomain by using a locally refined multiscale mesh at each time step,where conforming finite element pairs are used for the spatial discretizations and backward Euler scheme is used for the temporal discretizations,*** subproblem is defined in the entire domain with vast majority of the degrees of freedom associated with the particular subdomain that it is responsible for and hence can be solved in parallel with other subproblems using an existing sequential solver without extensive *** algorithm is easy to implement and has low communication *** bounds of the parallel finite element approximate solutions are *** experiments are also given to demonstrate the effectiveness of the algorithm.

关键词： Oseen equations finite element overlapping domain decomposition backward Euler scheme parallel algorithm

SYNTHESIS AND PROPERTIES OF NEW SIDE-CHAIN LIQUID CRYSTALLINE POLYMER WITH LATERALLY ATTACHED MESOGENS BY ESTER GROUP

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 1999年第5期17卷 499-502页

作者： qi-ding Mi qi-feng Zhou Department of Polymer Science&Engineering College of ChemistryPeking UniversityBeijing 100871China

New liquid crystalline monomer,2,5-bis[(4'-methoxyphenoxy)carbonyl]phenyl acrylate was successfully *** with laterally attached mesogens via ei;ter linkage was also *** polymer forms an enantiotropic liquid crystal phase while its monomer exhibits a metastable nematic phase with respect to the crystalline ***,its liquid crystallinity is very low as compared to that of poly{2,5-bis[(4'-methoxyphenoxy)carbonyl]-styrene}.

关键词： poly{2,5-bis[(4'-methoxyphenoxy)carbonyl]phenyl acrylate} hydroxyterephthalic acid mesogen-jacketed liquid crystalline polymers