检索结果-南通市图书馆

1-set-contractive perturbations of accretive operators in Menger PN-spaces

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2012年第3期27卷 363-370页

作者： WU Zhao-qi zhu chuan-xi Department of Mathematics Nanchang UniversityNanchang 330031China

Based on the topological degree for 1-set-contractive fields established in [11], we discuss the 1-set-contractive perturbation and the existence of zero points for nonlinear equations with accretive mappings in Menge... 详细信息

关键词： topological degree 1-set-contractive perturbation accretive mapping.

Topological degree for 1-set-contractive fields in M-PN spaces and its applications

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2010年第4期25卷 463-474页

作者： WU Zhao-qi zhu chuan-xi Department of Mathematics Zhejiang University Hangzhou 310027 China Department of Mathematics Nanchang University Nanchang 330031 China

In this paper, we define the topological degree for 1-set-contractive fields in PN spaces. Based on this, we obtain some new fixed point theorems for 1-set-contractive operators. As an application, we study the existe... 详细信息

关键词： PN-space 1-set-contractive operator topological degree fixed point theorem.

Torrent risk zonation in the Upstream Red River Basin based on GIS

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2006年第4期16卷 479-486页

作者： TANG chuan zhu Jing National Professional Laboratory for Geo-Hazard Prevention and Geo-Environment Protection Chengdu University of Technology Chengdu 610059 China

This paper explores the methodology for compiling the torrent hazard and risk zonation map by means of GIS technique for the Red River Basin in Yunnan province of China, where is prone to torrent. Based on a 1：250,000 scale digital map, six factors including slope angle, rainstorm days, buffer of river channels, maximum runoff discharge of standard area, debris flow distribution density and flood disaster history were analyzed and superimposed to create the torrent risk evaluation map. Population density, farmland percentage, house property, and GDP as indexes accounting for torrent hazards were analyzed in terms of vulnerability mapping. Torrent risk zonation by means of GIS was overlaid on the two data layers of hazard and vulnerability. Then each grid unit with a resolution of 500 m- 500 m was divided into four categories of the risk： extremely high, high, moderate and low. Finally the same level risk was combined into a confirmed zone, which represents torrent risk of the study area. The risk evaluation result in the upper Red River Basin shows that the extremely high risk area of 13,150 km^2 takes up 17.9% of the total inundated area, the high risk area of 33,783 km^2 is 45.9%, the moderate risk area of 18,563 km^2 is 25.2% and the low risk area of 8115 km^2 is 11.0%.

关键词： torrent risk zonation GIS the Upstream Red River Basin

First-principles calculations of structural,elastic and electronic properties of(TaNb)0.67(HfZrTi)0.33 high-entropy alloy under high pressure

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2020年第10期27卷 1405-1414页

作者： Zhi-sheng Nong Hao-yu Wang Jing-chuan zhu School of Materials Science and Engineering Shenyang Aerospace UniversityShenyang 110136China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

To clarify the effect of pressure on a(TaNb)0.67(HfZrTi)0.33 alloy composed of a solid solution with a single body-centered-cubic crystal structure,we used first-principles calculations to theoretically investigate the structural,elastic,and electronic properties of this alloy at different *** results show that the calculated equilibrium lattice parameters are consistent with the experimental results,and that the normalized structural parameters of lattice constants and volume decrease whereas the total enthalpy differenceΔE and elastic constants increase with increasing ***(TaNb)0.67(HfZrTi)0.33 alloy exhibits mechanical stability at high pressures lower than 400 *** high pressure,the bulk modulus B shows larger values than the shear modulus G,and the alloy exhibits an obvious anisotropic feature at pressures ranging from 30 to 70 *** analysis of the electronic structures reveals that the atomic orbitals are occupied by the electrons change due to the compression of the crystal lattices under the effect of high pressure,which results in a decrease in the total density of states and a wider electron energy *** factor is favorable for zero resistance.

关键词： first-principles calculations elastic property electronic structure density of states high-entropy alloys high pressure

Expedient Trifluoromethylacylation of Styrenes Enabled by Photoredox Catalysis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2022年第1期40卷 59-64页

作者： Lu Wang Heng Zhang chuan zhu Chao Feng Technical Institute of Fluorochemistry(TIF) Institute of Advanced Synthesis(IAS)School of Chemistry and Molecular EngineeringNanjing Tech University30 South Puzhu RoadNanjingJiangsu 211816China

Herein,we disclosed a photoredox enabled protocol for trifluoromethylacylation of styrenes through a radical-carboanion cascade and subsequent *** a broad range of aldehydes and inexpensive Langlois reagent as acyl and CF3 precursor,respectively,the alkene motif could be readily converted into β-trifluoromethyl ketones in moderate to good yields and with excellent *** CF3,di-,mono-and non-fluorinated C-radicals were revealed amenable in this reaction,providing good opportunity for the construction of structurally diverse ketones of interest in pharmaceutical ***,the utility of this protocol was further demonstrated by successful extension to trifluoromethylarylation and-alkylation by employing arylcyanide or acrylates in place of carbonyls.

关键词： Trifluoromethylacylation Alkenes Photocatalysis CF_(3)radical Radical-polar crossover

Numerical study on transom stern ventilation and resistance of high-speed ship in calm water

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

Journal of Hydrodynamics 2022年第5期34卷 864-875页

作者： Hui Wang Ren-chuan zhu Meng-xiao Gu Le Zha State Key Laboratory of Ocean Engineering School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Marine Design and Research Institute of China Shanghai200011China

A transom stern is a common design feature for a high-speed *** the present study,the transom stern ventilation of NPL 3b,5b hull is investigated by three methods:H−H formula,Doctors’formula,and computational fluid dynamics(CFD)method at *** the CFD method,the ratios of the wave elevation and wetted area are used to determine the transom *** of results show that Doctors’formula is more accurate to calculate the critical transom draft Froude *** then a Rankine panel method(RPM)based on the high-order boundary element method incorporated the modified transom stern condition is implemented to evaluate the steady wave problem of a high-speed fishery patrol ship in calm ***,free-surface(FS)and double body(DB)simulations based on Star-CCM+are carried out to obtain the wave-making resistance and total *** results of the resistance and wave pattern around the fishery patrol ship computed by RPM show generally good agreement with experimental measurement and CFD *** results indicate that the developed Rankine panel method with transom condition could predict the resistance of high-speed displacement ships with good accuracy.

关键词： Transom ventilation computational fluid dynamics(CFD)method Rankine panel method(RPM) high-speed ship double body simulation resistance

Upregulation of Interleukin 21 and Interleukin 21 Receptor in Patients with Dermatomyositis and Polymyositis

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 Medical Journal 2017年第17期130卷 2101-2106页

作者： Tao Liu Ying Hou Ting-Jun Dai chuan-zhu Yan Research Institute of Neuromuscular and Neurodegenerative Diseases Department of Neurology Qilu Hospital Shandong University JinanShandong 250012 China Department of Neurology The Affiliated Hospital of Qingdao University Qingdao Shandong 266003 China Research Institute of Neuromuscular and Neurodegenerative Diseases Department of Neurology Qilu Hospital Shandong University JinanShandong 250012 China Research Institute of Neuromuscular and Neurodegenerative Diseases Department of Neurology Qilu Hospital Shandong University JinanShandong 250012 China Brain Science Research Institute Shandong University Jinan Shandong 250012 China

Background：The immunopathologic mechanism underlying dermatomyositis （DM） and polymyositis （PM） remains poorly *** cytokines play a pathogenic role in DM and *** 21 （IL-21） has a pleiotropic effect on inflammation *** study aimed to detect the serum IL-21 level and investigate the expression of IL-21 and IL-21 receptor （IL-21 R） in muscle tissues of patients with DM and ***：Biopsied muscle samples were obtained from 11 patients with DM,12 with PM,and six controls;mRNA levels of IL-21 and IL-21 R were analyzed by real-time quantitative reverse transcription-polymerase chain reaction;and immunohistochemical staining was used to evaluate the protein expression of IL-21 and *** samples were obtained from 36 patients with DM,19 with PM,and 20 healthy *** serum IL-21 level was detected by enzyme-linked immunosorbent ***：The expression of IL-21 was upregulated in patients with DM and *** IL-21 mRNA level was significantly increased in muscle tissues of patients with DM and PM （DM ***,P =0.001;PM ***,P =0.001）,whereas IL-21R mRNA level in patients with DM/PM was not statistically different from that of healthy *** staining showed both I L-21 and IL-21R were significantly expressed in the inflammatory cells in muscle tissues of patients with DM and *** serum IL-21 level was also significantly higher in patients with DM/PM than in controls （DM ***,49.12 [45.28,60.07] pg/ml vs.42.54 [38.69,48.85] pg/ml,P =0.00l;PM ***,50.77 [44.19,60.62] pg/ml vs.42.54 [38.69,48.85] pg/ml,P =0.005）.Conclusions：IL-21 expression is upregulated in patients with DM and PM in both muscle tissue and *** addition,IL-21R protein is highly expressed in affected muscle tissues of patients with DM and ***-21 may play a pathogenic role through IL-21R in patients with DM and PM.

关键词： Dermatomyositis Interleukin 21: lnterleukin 21 Receptor Polymyositis

Strong Approximations for a Kumar-Seidman Network under a Priority Service Discipline

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2010年第4期26卷 587-596页

作者： Lin Wu chuan-xi zhu Yun-jiang Wu Department of Mathematics Nanchang UniversityNanchang330031China Department of Mathematics Xi'an Jiao Tong UniversityXi'anChina

In this paper,we derive the strong approximations for a four-class two station multi-class queuing network（Kumar-Seidman network） under a priority service *** a group,jobs are served in the order of arrival,that is,a first-in-first-out disciple,and among groups,jobs are served under a pre-emptiveresume priority *** show that if the input data（i.e.,the arrival and service processe） satisfy an approximation（such as the functional law-of-iterated logarithm approximation or the strong approximation）,the output data（the departure processes） and the performance measures（such as the queue length,the work load and the sojourn time process） satisfy a similar approximation.

关键词： Strong approximation diffusion approximation priority service discipline Kumar-Seidman network

An investigation on HOBEM in evaluating ship wave of high speed displacement ship

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2019年第3期31卷 531-541页

作者： Xi Chen Ren-chuan zhu Ya-lan Song Ju Fan Marine Design & Research Institute of China Shanghai 200011 China State Key L aboratory of Ocean Engineering Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

A practical numerical tool is developed to evaluate ship waves of high speed displacement ships on the basis of potential flow theory, in which high order boundary element method (HOBEM) based on biquadratic shape functions is applied to solve the boundary value problem. Since the sinkage and trim of ship at high speeds are notable, influences of ship attitude on wave drag are investigated and three kinds of models are used to evaluate them. To make the numerical approach highly efficient, an incomplete LU factorization preconditioner is adopted and incorporated with the restarted generalized minimal residual method GMRES (m) to solve the boundary integral equation. A corresponding Fortran code is developed and applied to evaluate ship waves of the Wigley hull and 4a model, a transom stem ship. Computations are performed for both monohulls and catamarans over a wide range of Froude numbers (Fr= 0.10-l.00). Numerical issues including mesh convergence and computational efficiency are investigated at first. Computed results of the wave drag, sinkage and trim show generally good agreement with experimental data. Reasonable wave patterns are obtained and physical phenomena that wake angle max, where the largest waves occur, would become narrow at high speeds is also captured by the present computations. Numerical results indicate the proposed method would be accurate and efficient to evaluate resistance for hull design of high speed displacement ship.

关键词： High speed ship ship waves HOBEM ILU-GMRES sinkage and trim