检索结果-南通市图书馆

Communications in Theoretical Physics 2002年第3期37卷 269-276页

作者： yaNZhen－ya DepartmentofAppliedMathematics DalianUniversityofTechnologtyDalian116024China

We have found two types of important exact solutions, compacton solutions, which are solitary waves with the property that after colliding with their own kind, they re-emerge with the same coherent shape very much as the solitons do during a completely elastic interaction, in the and even models, and dromion solutions (exponentially decaying solutions in all direction) in many and models. In this paper, symmetry reductions in are considered for the break soliton-type equation with fully nonlinear dispersion (called equation) , which is a generalized model of break soliton equation , by using the extended direct reduction method. As a result, six types of symmetry reductions are obtained. Starting from the reduction equations and some simple transformations, we obtain the solitary wave solutions of equations, compacton solutions of equations and the compacton-like solution of the potential form (called ) . In addition, we show that the variable admits dromion solutions rather than the field itself in equation.

关键词： BS(m, n) equations PBS(m, n) equation symmetry reduction solitary wave solution dromion solution compacton solution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2001年第10期36卷 385-390页

作者： yaN Zhen-ya Department of Applied Mathematics Dalian University of Technology Dalian 116024 China

In this paper, similarity rcductions of Boussinesq-like equations with nonlinear dispersion (simply called B(m, n) equations) utt = (un)xx + (um) which is a generalized model of Boussinesq equation uts = (u2)xx + u and modified Bousinesq equation utt = (u3)xx + uxxxx, are considered by using the direct reduction method. As a result,several new types of similarity reductions are found. Based on the reduction equations and some simple transformations,we obtain the solitary wave solutions and compacton solutions (which are solitary waves with the property that after colliding with other compacton solutions, they re-emerge with the same coherent shape) of B(1, n) equations and B(m, m)equations, respectively.

关键词： nonlinear evolution equation, B(m, n) equations, similarity reduction, solitary wave solution,compacton solution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2001年第11期36卷 513-518页

作者： yaN Zhen-ya Department of Applied Mathematics Dalian University of TechnologyDalian 116024China

In this paper,eight types of (1-+1)-dimensional similarity reductions which contain variable coefficient equation,are obtained for the generalized KdV equation in (2+1)-dimensional space arising from the multidimensional isospectral flows associated with the second-order scalar operators by using the direct *** addition,the cnoidal wave solution and dromion-like solution are also derived by using the reduced nonlinear ordinary differential *** (1+1) dromion obtained by Lou [***.A28 (1995) 7227] and Zhang [***.9 (2000) 1] is only a special case of our ***,some properties of the dromion-like solutions are analyzed.

关键词： generalized KdV equation,similarity reduction,Painlevé-I equation,Painlevé-II equation,cnoidal waves,dromion-like solution

Thermoelectric converter based on metal-dielectric-semiconductor-metal structures for cooling processors

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 Advanced Dielectrics 2020年第1期10卷 42-47页

作者： g.ya.Karapetyan I.A.Parinov g.Parchiy I.I.Vorovich Institute of Mathematics Mechanics and Computer Sciences Southern Federal University Rostov-on-Don 344090 Russia

A thermoelectric transducer based on MDSM structures of the field-effect transistor(FET)type is proposed,in which the thermal energy of the environment is converted into electrical *** use a new principle of converting thermal energy into electrical *** show that with the help of such a converter,it is possible to dramatically increase the efficiency of processors due to the heat generated by the processor is converted by this converter again into electricity that transfers to the processor.

关键词： Crystal growth thermoelectric converter field-effect transistor metal-dielectric-semiconductor-metal(MDSM)structure processor

行距配置和种植密度对棉花干物质生产及产量的影响

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

作物学报 2025年第1期51卷 221-232页

作者：辛明华秘雅迪王国平李小飞李亚兵董合林韩迎春冯璐中国农业科学院棉花研究所/棉花生物学国家重点实验室河南安阳455000 中国农业科学院西部农业研究中心新疆昌吉831100

行距配置和种植密度是影响棉花产量和品质的重要因素。当前新疆棉花种植主要采用宽窄行配置,也有等行距配置方式,但对这两种方式的认识尚存在争议。为此,本研究以中棉所88号为供试材料,采用裂区设计,行距配置(等行距和宽窄行)为主区,种... 详细信息

行距配置和种植密度是影响棉花产量和品质的重要因素。当前新疆棉花种植主要采用宽窄行配置,也有等行距配置方式,但对这两种方式的认识尚存在争议。为此,本研究以中棉所88号为供试材料,采用裂区设计,行距配置(等行距和宽窄行)为主区,种植密度12×104株hm^(–2) (D1)、16×104株hm^(–2) (D2)和18×104株hm^(–2) (D3)为裂区,开展了2年大田试验,比较研究了行距配置和密度对棉花群体生长发育、干物质积累和分配、以及产量和纤维品质的影响。结果表明,中等密度(16×10^(4)株hm^(–2))下等行距和宽窄行处理组合的叶面积指数(LAI)增速、LAI峰值,以及吐絮期生殖器官生物量的分配比例均高于其他处理组合,且二者无显著差异。各处理组合间的棉花群体生长率(CgR)、净同化率(NAR)和棉铃生长率(BgR)均无显著差异。2年平均,中等密度下等行距和宽窄行处理组合的籽棉产量相当,纤维品质指标也无显著差异。表明在中等密度下,无论采用等行距还是宽窄行种植模式,均能达到理想的产量和品质。本研究为新疆棉花行距配置和密度选择提供了科学依据。

关键词：棉花单双行配置密度生长指标干物质积累与分配产量及品质

Possibility of observation of hidden-bottom pentaquark resonances in bottomonium photoproduction on protons and nuclei near threshold

同方期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2020年第10期44卷 87-97页

作者： E.ya.Paryev Institute for Nuclear Research Russian Academy of SciencesMoscow 117312Russia Institute for Theoretical and Experimental Physics Moscow 117218Russia

We study theΥ(1S)meson photoproduction on protons and nuclei at near-threshold center-of-mass energies below 11.4 geV(or at the corresponding photon laboratory energies Eγbelow 68.8 geV).We calculate the absolute excitation functions for the nonresonant and resonant photoproduction ofΥ(1S)mesons off protons at incident photon laboratory energies of 63-68 geV by considering direct(γp→Υ(1S)p)and two-step(γp→P^+b(11080)→Υ(1S)p,γp→P^+b(11125)→Υ(1S)p,γp→P^+b(11130)→Υ(1S)p)Υ(1S)production channels within different scenarios for the nonresonant total cross section of the elementary reactionγp→Υ(1S)p and for branching ratios of the decays P^+b(11080)→Υ(1S)p,P^+b(11125)→Υ(1S)p,and P^+b(11130)→Υ(1S)*** also calculate an analogous function for the photoproduction ofΥ(1S)mesons on the 12C and 208Pb target nuclei in the near-threshold center-of-mass beam energy region of 9.0-11.4 geV by considering the respective incoherent direct(γN→Υ(1S)N)and two-step(γp→P^+b(11080)→Υ(1S)p,γp→P^+b(11125)→Υ(1S)p,γp→P^+b(11130)→Υ(1S)p andγn→P^0b(11080)→Υ(1S)n,γn→P^0b(11125)→Υ(1S)n,γn→P^0b(11130)→Υ(1S)n)Υ(1S))production processes using a nuclear spectral function *** demonstrate that a detailed scan of theΥ(1S)total photoproduction cross section on proton and nuclear targets in the near-threshold energy region in future high-precision experiments at the proposed high-luminosity electron-ion colliders EIC and EicC in the US and China should provide a definite result for or against the existence of the nonstrange hidden-bottom pentaquark statesP^+bi and P^0bi(i=1,2,3)as well as clarify their decay rates.

关键词： photon-nucleus reactions bottomonium production hidden-bottom pentaquarks

Energy transfer mechanism of PBS-thylakoid complexes——By time-resolved fluorescence spectra technique

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第20期42卷 1699-1703页

作者： Zhang, JM Zhao, JQ Jiang, LJ Zheng, xg Zhao, FL Wang, HZ Acad Sinica Inst Photog Chem Beijing 100101 Peoples R China

IN a previous paper, we have studied the energy transfer mechanism among the PBS-thy-lakoid complex in detail by using steady-state spectra and deconvolution techniques. The ex-perimental results indicated that the energy transfer from PBS to two reaction centers of PS Ⅰand PS Ⅱ were parallel, and confirmed the model which was suggested by Mullineaxu.

关键词： PBS-thylakoid complex time-resolved fluorescence spectra energy transfer.

同方期刊数据库

Synthesis and hydrodesulfurization of zirconium binary nitrides

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第15期42卷 1274-1278页

作者： Zhang, YJ Zhao, xg Zhou, ZH yan, WH Ying, PL Xin, Q CHINESE ACAD SCI DALIAN INST CHEM PHYSDALIAN 116023PEOPLES R CHINA

As a new material to be used widely in catalytic field, γ-Mo2N with high specific surface area(usually, SBET>100 m2·g-1 has recently aroused much attention. Its catalytic activities re-semble those of noble metals （Rh, Pd and Pt） in hydrogenation of hydrocarbon. Especially,it has some marvelous characteristics for deep hydrodesulfurization （HDS）, hydrodeni-

关键词： high surface area binary nitrides hydrodesulfurization H2-TPD.

Preparation and Characterization of Anthracenecarboxylic Acid Doped Polyaniline Thin Films

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2014年第8期32卷 1060-1067页

作者： ya-fang Tian 谭付瑞 Zhengzhou Railway Vocational & Technical College Key Laboratory of Photovoltaic Materials Department of Physics & ElectronicsHenan University

Doped polyaniline films were prepared with electrochemistry method. A small conjugated molecule; anthracenecarboxylic acid （2-ACA）, was used as the dopant, considering its electrical activeness due to the conjugated π-π structure. Film morphology of doped and undoped polyaniline samples was investigated. The corresponding changes in optical and electrical properties after ACA doping were discussed. By measuring and calculating their energy level distribution, a promising application of polyaniline thin films as buffer layer in optic-electric devices is expectable.

关键词： Electrochemistry Polyaniline (PANI) Doping Solar cells.

Near-threshold K^*(892)^+ meson production in the interaction of π−mesons with nuclei

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2020年第11期44卷 168-178页

作者： E.ya.Paryev Institute for Nuclear Research Russian Academy of SciencesMoscow 117312Russia Institute for Theoretical and Experimental Physics Moscow 117218Russia

We study the inclusive production of strange vector K^∗(892)^+ mesons in π−A reactions at near-threshold laboratory incident pion momenta of 1.4-2.0 geV/c via a nuclear spectral function *** approach accounts for incoherent primary π−meson-proton π−p→K^∗(892)^+Σ^− production processes as well as the influence of the scalar K^∗(892)^+-nucleus potential(or the K^∗(892)^+ in-medium mass shift)on these *** calculate the absolute differential and total cross sections for the production of K∗(892)+mesons from carbon and tungsten nuclei at laboratory angles of 0∘-45∘and at the aforementioned momenta in five scenarios for the aforenoted *** show that the K^∗(892)^+ momentum distributions and their excitation functions(absolute and relative)possess a high sensitivity to changes in the in-medium K^∗(892)^+ mass shift in the low-momentum region of 0.1-0.6 geV/***,the measurement of such observables in a dedicated experiment at the gSI pion beam facility in the near-threshold momentum domain will allow us to get valuable information on the K^∗(892)^+ in-medium properties.

关键词： pion-nucleus reactions strange vector meson production in-medium effects