检索结果-南通市图书馆

STEADY-STATE SOLUTIONS FOR A ONE-DIMENSIONAL NONISENTROPIC HYDRODYNAMIC MODEL WITH NON-CONSTANT LATTICE TEMPERATURE

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2008年第3期28卷 479-488页

作者：黎野平 Department of mathematics Xianning College

A one-dimensional stationary nonisentropic hydrodynamic model for semiconductor devices with non-constant lattice temperature is studied. This model consists of the equations for the electron density, the electron current density and electron temperature, coupled with the Poisson equation of the electrostatic potential in a bounded interval supplemented with proper boundary conditions. The existence and uniqueness of a strong subsonic steady-state solution with positive particle density and positive temperature is established. The proof is based on the fixed-point arguments, the Stampacchia truncation methods, and the basic energy estimates.

关键词： Steady-state nonisentropic hydrodynamic model semiconductor subsonic

Randomization of classical inference patterns and its application

在线全文

学校读者我要写书评

暂无评论

science in china(Series F) 2007年第6期50卷 867-877页

作者： WANG GuoJun1,2 & HUI XiaoJing1,31 Institute of mathematics, Shaanxi normal university, Xi’an 710062, china 2 Research Center for science, Xi’an Jiaotong university, Xi’an 710049, china 3 college of mathematics and Computer science, Yan’an university, 716000, china 1. Institute of mathematics Shaanxi Normal University Xi’an 710062 China 2. Research Center for science Xi’an Jiaotong University Xi’an 710049 China 3. college of mathematics and Computer science Yan’an University 716000 China

By means of randomization, the concept of D-randomized truth degree of formulas in two-valued propositional logic is introduced, and it is proved that the set of values of D-randomized truth degree of formulas has no isolated point in [0,1]. The concepts of D-logic pseudo-metric and D-logic metric space are also introduced and it is proved that there is no isolated point in the space. The new built D-randomized concepts are extensions of the corresponding concepts in quantified logic. Moreover, it is proved that the basic logic connectives are continuous operators in D-logic metric space. Lastly, three different types of approximate reasoning patterns are proposed.

关键词： D-randomized mapping D-randomized truth degree D-similarity D-logic metric space approximate reasoning

ON F-z-SUPPLEMENTED SUBGROUPS OF FINITE GROUPS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2011年第1期31卷 22-28页

作者：郭文彬唐娜李保军 Department of mathematics University of Science and Technology of China Department of mathematics Xuzhou Normal University Department of mathematics Huaiyin Teachers College School of mathematics Chengdu University of Information Technology

A subgroup H of a group G is called F-z-supplemented in G if there exists a subgroup K of G, such that G = HK and H∩K≤ Z∞F（G）, where Z∞F（G） is the F-hypercenter of G. We obtain some results about the F-z-suppl... 详细信息

关键词： Finite groups local formations F-z-supplemented subgroups supersoluble groups p-nilpotent groups

CURVILINEAR PATHS AND TRUST REGION METHODS WITH NONMONOTONIC BACK TRACKING TECHNIQUE FOR UNCONSTRAINED OPTIMIZATION

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 241-258页

作者： De-tong Zhu (Department of mathematics, Shanghai normal university, Shanghai 200234, china) 上海师范大学上海 200234

Focuses on a study which examined the modification of type approximate trust region methods via two curvilinear paths for unconstrained optimization. Properties of the curvilinear paths; Description of a method which combines line search technique with an approximate trust region algorithm; information on the convergence analysis; Details on the numerical experiments.

关键词： curvilinear paths trust region methods nonmonotonic technique unconstrained optimization

Effect of lead on survival, locomotion and sperm morphology of Asian earthworm, Pheretima guillelmi

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2009年第5期21卷 691-695页

作者： ZHENG Rongquan, LI Canyang college of Chemistry and Life science, Zhejiang normal university, Jinhua 321004, china. [a]college of Chemistry and Life science Zhejiang Normal University Jinhua 321004 China

To provide basic toxicity data for formulating risk characterization benchmarks, the effects of lead on survival, locomotion, and sperm morphology were investigated in the Asian earthworm Pheretima guillelmi. The LC50 of P. guiUelmi for 7 and 14 d were 4285＋339 mg/kg and 3207＋248 mg/kg, which shows P. guillelmi can tolerate a higher concentration of lead nitrate. The average weight of the surviving earthworms decreased at concentration of 2800 mg Pb/kg soil, and the locomotor ability of earthworms exposed to a range of soil Pb concentrations showed a general decrease with increasing Pb concentrations. We also presented data depicting the sperm morphology of earthworms, which shows potential as a sensitive biomarker for measuring the effects of heavy metal on reproduction.

关键词： lead Pheretima guillelmi sperm morphology locomotion

The environmental signal of an early Holocene pollen record from the Shiyang River basin lake sediments, NW china

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 2002年第4期47卷 267-273页

作者： ZHU Yan, CHEN Fahu & Madsen Davidcollege of geography and Environment, northwest normal university, lanzhou 73.070, china National Key Laboratory of West Environmental System, lanzhou university, lanzhou 730000, china Utah Geological Surv college of geography and Environment Northwest Normal University National Key Laboratory of West Environmental System Lanzhou University

Pollen analyses of 85 samples from the San-jiaocheng section well along the margin of a palaeolake at the end of the Shiyang River, NW china, show that Picea and Sabina dominate the pollen assemblage. Together they reach as high as 40%-60%, with the percentage of Picea varying inversely with that of Sabina. Similar results were obtained from another section in the Shiyang River drainage. Using modern ecological habitat relationship analogues, pol-len transport characteristics, and the overall pollen assem-blage, we propose that both Picea and Sabina pollen were transported by the river from the mountains at the upper reaches of the Shiyang River, and that the assemblage is more indicative of changes in upland vegetation than of local conditions near the section. This interpretation is supported by pollen data derived from surface samples, water samples, and riverbed samples. Using a moisture indicator (the Picea to Sabina ratio) and calculated pollen concentrations, we identify a series of

关键词： NW china The environmental signal of an early Holocene pollen record from the Shiyang River basin lake sediments

Lattice dynamical simulation of methane hydrate

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2010年第1期19卷 43-46页

作者： Lin Wang, Shunle Dong Physics Department, college of information science and Engineering, Ocean university of china, Qingdao 266100, Shandong, china [a] Physics Department College of Information Science and Engineering Ocean University of China Qingdao 266100 Shandong China

INS （Inelastic Neutron Scattering） spectrum of methane hydrate was measured on MARI （a direct-geometry chopper spectrometer） at Ruther-ford Appleton Laboratory, UK. Compared with ice Ih, it is found that the whole spectrum of methane hydrate moves toward high-energy by about 1.5 meV. Using lattice dynamical （LD） technique, computer simulations of methane hydrate were carried out. In the simulations, four potential models （BE TIP3P, TIP4P, MCY） were employed to calculate the phonon density of states （PDOS）. Comparing the calculated PDOS spectrum with the experimental spectrum, it is found that BF, TIP4P, and TIP3P potential lattices give out well-separated translational and librational bands while MCY potential lattice is unstable to do so and this model is not suitable to describe hydrate system.

关键词： methane hydrate inelastic neutron scattering lattice dynamical simulation

Property(ω) and Its Perturbations

在线全文

学校读者我要写书评

暂无评论

Journal of Mathematical Research with Applications 2012年第4期32卷 450-458页

作者： Qiaoling XIN,Xiaohong CAO college of mathematics and information science,Shaanxi normal university,Shaanxi 710062,P.R.china college of mathematics and information science Shaanxi Normal University Shaanxi 710062

In the note,we establish for a bounded linear operator defined on a Hilbert space the necessary and sufficient conditions for the stability of property(ω) by means of the variant of the essential approximate point spectrum and the induced spectrum of consistency in Fredholm and *** addition,the stability of property(ω) for H(P) operators is considered.

关键词： property(ω) perturbation consistency in Fredholm and index.

Investigations into quantum correlation of coupled qubits in a squeezed vacuum reservoir

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第2期22卷 86-91页

作者：嵇英华刘咏梅 Department of Physics Jiangxi Normal University Key Laboratory of Photoelectronics and Telecommunication of Jiangxi Province college of mathematics and information science Jiangxi Normal University

In this paper,we investigate the quantum correlation of coupled qubits which are initially in maximally entangled mixed states in a squeezed vacuum *** compare and analyze the effects of squeezed parameters on quantum discord and quantum *** results show that in a squeezed vacuum reservoir,the quantum discord and quantum concurrence perform with completely opposite behaviors with the change of squeezed *** discord survives longer with the increase of squeezed amplitude parameter,but entanglement death is faster on the *** results also indicate that the classical correlation of the system is smaller than quantum discord in a vacuum reservoir,while it is bigger than quantum discord in a squeezed vacuum *** quantum discord and classical correlation are more robust than quantum concurrence in the two reservoir environments,which indicates that the entanglement actually is easily affected by decoherence and quantum discord has a stronger ability to avoid decoherence in a squeezed vacuum reservoir.

关键词： quantum correlation coupled qubits quantum discord concurrence