作为同态与反同态的广义( θ,θ) - 导子的研究

R是2-扭自由素环,I是R上的非零理想,θ是R上的自同构,F是R上的与(θ,θ)-导子d有关的非零广义(θ,θ)-导子,有F(xy)=F(x)F(y)或F(xy)=F(y)F(x),对所有的x,y属于I且d≠0,则R是可交换的.     

Resonance luminescence spectra of selenium （Ⅳ）－iodide－rhodamie B system and its analytical application

Ｒｅｓｏｎａｎｃｅｌｕｍｉｎｅｓｃｅｎｃｅｓｐｅｃｔｒａｏｆｓｅｌｅｎｉｕｍ（Ⅳ）－ｉｏｄｉｄｅ－ｒｈｏｄａｍｉｅＢｓｙｓｔｅｍａｎｄｉｔｓ　ａｎａｌｙｔｉｃａｌａｐｐｌｉｃａｔｉｏｎ￥ＬｉｕＳｈａｏｐｕ；ＬｉｕＺｈｏｎｇｆａｎｇ；ＬｉＭｉｎｇ（Ｓｃ...     

Rank of loop, constraint degree of path, coupling degree of graph and their application

Some new concepts (rank of a loop, degree of freedom of a graph, path unit and ordered path arrangement, constraint degree of path, coupling degree of a graph, basic graph, etc. ), formulas, and algorithms, are proposed in this paper. Based on these concepts, a new systematic theory and practical method for the design of topological structure, kinematics and dynamics of mechanical systems is established. Some conjectures and problems needed to be researched are also put forward. The concepts, formulae and algorithms presented in this paper will find wide potential applications.     

Mossbauer Spectra of Valleriite from China

在墨铜矿的结构中，Ｆｅ离子可占据硫化物层中四面体和氢氧化物层的八面体两种配位位置。穆斯堡尔谱结果表明：高自旋的Ｆｅ２＋占据四次配位位置，同质异能位移为０．４２～０．４８ｍｍｓ－１、四极分裂为０．８１～１．２８ｍｍｓ－１；低自旋的Ｆｅ３＋占据六次配位位置，同质异能位移为０．３２～０．３６     

Banach空间中非线性刚性DDEs θ-方法的数值稳定性

讨论Banach空间中非线性刚性变延迟微分方程θ-方法的数值稳定性,对Banach空间中的实验问题类D0(α,β)得到了θ -方法的稳定性及渐近稳定性.     

Characterization of Cu-Ti powder metallurgical materials

Powder metallurgical Cu-Ti alloys with different titanium additions produced by hot pressing were characterized by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and hardness, wear and bending tests. The addition of titanium to copper caused the formation of different intermetallic layers around titanium particles. The titanium content of the intermetallics decreased from the center of the particle to the copper matrix. The hardness, wear resistance, and bending strength of the materials increased with increasing Ti content, whereas strain in the bending test decreased. Worn surface analyses showed that different wear mechanisms were active during the wear test of specimens with different chemical compositions. Changes in the properties of the materials with titanium addition were explained by the high hardness of different Cu-Ti intermetallic phases.     

Tailores Design and Characterization of Peroxide-containing Linear, Blick and Highly Branched Oligoelectrolytes and Derived Functional Nanoparticles with Special Properties

1 Results The development of novel surface-active block, comb-like and branched copolymers with peroxide-containing chains as well as derived functional luminescent and magnetic nanoparticles are the objectives of presented study. Main experimental approaches based on tailored synthesis of the oligoperoxide surfactants of desired structures and derived coordinating complexes of transitional and rare earth elements are developed. Functional oligoperoxide based possibilities of the synthesis of luminescent, magnetic and other functional nanocomposites with controlled size distribution, functionality, reactivity and biocompatibility are presented. Developed methods provide combining the stage of formation of polymeric, metal and metal-oxide nanoparticles with the stage of their surface irreversible modification by functional fragments capable of radical and other reactions including binding physiologically active substances. Novel nanoparticles are studied by chemical, colloidal-chemical, and rheological methods, X-ray diffraction technique, luminescent spectroscopy, transmission and scanning electronic microscopy. The availability of ditertiary peroxide fragments on nanoparticle surface causes their ability to radical grafting functional polymer chains. Functional nanoparticles developed are studied in phagocytosis, as markers of pathological cells, antimicrobial remedies and nanocarriers for targeted drug delivery.     

Study of solid solution strengthening of alloying element with phase structure factors

Using the empirical electron theory of solids and molecules (EET), the phase structure factors, nA and nB, of the carbon-containing structural units with mass fraction of carbon (wC) below 0.8% and the mono-alloy structural units with wC at 0.2% in austenite and martensite are calculated. The solid solution strengthening brought by C-containing interstitial solid solution and alloy-substitutional solid solution in γ-Fe and α-Fe is discussed at electron structural level. The coefficient (s) of solid solution strengthening is advanced according to the bonding force between atoms. The study shows that when the criterion is applied to the carbonaceous or alloying element-containing solid solution the results of calculation will coincide with the experimental result very well.     

ISI Web of KnoWledge——学术信息最直接的途径

阐述了ISI Web of Knowledge新一代的学术信息资源体系及特点;并通过主要功能的分析,揭示了ISI Web of Knowledge提供学术信息资源的途径。     

Wake structures of two spheres in tandem arrangement at various gaps for Re = 300

The virtual boundary method is extended to a 3D application and used to simulate the flow field of two spheres in tandem arrangement for a Reynolds number of 300. The wake structures and flow spectra at various gaps are investigated. The numerical results show that for small gaps (≈1.5), due to the mutual suppress between the wakes of the two spheres, the full flow field is stable and axisymmetric. As the gap is increased to 2.0, an asymmetric but stable flow is constructed through a certain bifurcation. The downstream wake structure is characterized by a double-thread vortex structure that comprises two slender parallel vortex tubes. The double-thread structure has a planar symmetry at gap 2.0. The hairpin-shape vortices are periodically shed from the downstream sphere at gap 2.5, but the planar symmetry persists. The vortex structures at gaps ranging from 3.0 to 4.0 are irregular and the flow field is undergoing a kind of 3D transition. It is up to the large gap 5.0 that the hairpin-shape structures are reconstructed behind the upstream and the downstream sphere, and the planar symmetry is resumed. All these numerical computations were performed on an SGI Origin3900 machine at the Center for Engineering and Scientific Computation of Zhejiang University.     

Some characteristics of the atmosphere during an adiabatic process

Some important characteristics of the atmosphere during an adiabatic process are investigated, which include the invariability of atmospheric entropy range and local surface potential temperature, the conservation of the atmospheric mass intervened between any isentropic surface and the ground, and the isentropic surface intersecting with the ground. The analysis shows that the atmospheric reference state (ARS) for investigation on available potential energy (APE) should be defined objectively as the state which could be approached from the existing atmosphere by adiabatic adjustment, and be related to initial atmospheric state before adjustment. For the initial atmosphere state at any time, its corresponding ARS is different from the one at another time. Based on the above-mentioned conclusions, the reference state proposed by Lorenz cannot be obtained physically, so a new conception, the conditional minimum total potential energy, is put forward in order to objectively investigate atmospheric APE.     

Exact n-width on the class of analytic functions in the space of continuous functions

Let ω(·) be a given concave modulus of continuity and ω(g,·) be the modulus of continuity of a function g∈C, where C is the space of 2π-periodic, continuous functions on R with norm ‖f‖C∶=maxt∈R|f(t)|, r,ω∞,β(r=0,1,2,…) denotes those 2π-periodic, real-valued functions f on R that are analytic in the strip Sβ∶=｛z∈C：|Imz|＜β｝, β＞0, and satisfy the restriction condition: ω(f(r),·)≤ω(·). In this paper, the exact n-width of the class of functions r,ω∞,β in the space C is determined.     

Web of Science数据库的检索、链接及其功能

阐述了Weh of Science数据库的收录范围,结合实例介绍了该数据库的检索方法、检索技术.重点推介了Web of Science数据库的特色链接及其功能.     

Peculiar dynamical properties of plutonium hydrides

In the present work, the structure and spectra of PuH and PuH₂ are defined by B3LYP/SDD method, from which the analytic potential energy function of PuH₂ is derived. The analysis of quasi-classical molecular reaction dynamics is performed to study the state-state process of Pu(⁷F_g)+H₂(X¹Σ⁺_g). It is found that the reaction Pu(⁷F_g)+H₂(X¹Σ⁺_g)→PuH₂(X⁷B₁) has no threshold. The simultaneous hydrogenation process of plutonium with the main product of PuH₂ is theoretically proved for the first time.     

Type synthesis of parallel mechanisms with three translational degrees of freedom

A simple but effective type synthesis method for spatial parallel mechanisms with three translational degrees of freedom(DOF) based on the screw theory is presented. Firstly all possible connecting-chain structures of three-DOF parallel mechanisms are enumerated. According to the reciprocal relationship between screw constraint forces and the motion screw, a novel synthesis method is presented. By using this method, type synthesis for translational three-DOF parallel mechanisms has been made in a systematic and detailed way. As a result, dozens of novel parallel mechanisms generating spatial translation have been obtained. To verify the significance of type synthesis for this kind of mechanism, this paper also gives an example of application, which is used for a micromanipulator for manipulating cells     

英语书面语中的所有格和of结构的语料库分析

英语中所有格和of结构已经是广大英语学习者熟悉的语言现象了。很多学者对此进行了研究,也得出不少结论。然而,对此现象的语料库研究却是少之又少。应从语料库语言学的角度探讨英语书面语中的所有格和of结构,特别是修饰语的词性和短语结构的语义关系对此产生的影响。     

Some inequalities of Hadamard＇ s type for Lipschitz mappings

给出满足Lipschitz条件的凸函数的一些Hadamard型不等式,推广了已有文献的结果.