尖晶石型结构的微变化规律性

本文利用特征离子坐标变化的术语对尖晶石型结构的微变化规律性进行了讨论.总结出u值与A、B阳离子的变化规律.     

暗棕色森林土母质层团聚体数量随高度变化

团聚体是土壤结构的重要组成部分,本文研究了暗棕壤母质层各粒级团聚体随高度的变化情况,结果表明母质层各粒级团聚体数量相比,小团聚体含量最高,为优势粒级,各随高度变化均不相同,但大团聚体（＆gt;0.25mm）数量随海拔高度的增加而增加,微团聚体（〈0.25mm）数量变化相反。     

Ф压缩型集值映射列的公共不动点定理

在度量空间中,研究了Ф压缩型集值映射列的公共不动点定理,给出了如下结果：设集值映射序列Ai：X→Pf（x）满足：任意ij=1,2,…,x,y∈X及u∈Ax,存在v∈Ay,使得d（u,v）≤Ф（d（x,y）,d（x,Ax）,d（y,Aiy）,d（y,Aix））：则{Ai}有公共不动点。     

西安城市化进程对城市用水的影响

随着城市化进程的快速发展,西安非农业人口不断增加,经济增长和产业结构升级,使得城市用水量和用水部门结构也在随之发生着相应的变化,水资源供需矛盾日趋突出,严重制约着城市的可持续发展。根据西安市1978年-2007年城市用水和城市化有关数据资料,应用数理统计分析方法分析了西安城市化程度,在此基础上构建了城市化程度对城市用水量影响的关系模型,并对城市化主要指标和城市用水部门结构进行曲线拟合,探究西安城市化主要指标对城市用水部门结构的影响,为促进西安城市可持续发展提供一定的科学参考。研究表明:随着城市化进程的快速发展,西安城市用水量呈波动增加趋势,但增长速度逐渐降低。城市用水部门结构也发生着相应的变化,城市生活用水量随人口城市化率的变化呈现单调上升的特征;生产用水量随GDP的变化呈倒"U"型线走势,符合库兹涅茨曲线规律。     

电流对喷射电沉积纳米晶镍结构和硬度的影响

在喷射电沉积装置上,采用直流和方波脉冲两种电流波形,在不同的电流密度下制备纳米晶镍镀层。详细研究了电流波形、电流密度对镀层晶粒生长、微观结构和硬度的影响。结果表明:随着电流密度的增加,在两种电流波形下沉积的镀层的微观结构,展示出完全不同的变化趋势。镀层硬度随电流密度的变化趋势,主要由晶粒尺寸随电流密度的变化决定,总体上,硬度值随晶粒尺寸的减小而增大。在相同的晶粒尺寸范围,脉冲镀层的硬度值要高于直流镀层。     

一种复合型光子晶体微谐振腔

提出了一种基于介质基片上的周期性空气槽和一条有缺陷的线形周期性空气孔复合型二维光子晶体微谐振腔.利用FDTD方法对所提出的结构进行了数字模拟,模拟结果证实了这种结构在光子禁带区域内存在谐振模式,是一种有效的微谐振腔.这种微谐振腔的谐振波长主要由空气孔的周期和缺陷区的长度决定,而周期数量的多少对谐振波长的影响较小.当空气槽参数固定时,谐振波长与空气孔的周期成正比.在一定的范围内,谐振波长随缺陷区的长度增加而近似线性增加.谐振腔的品质因子随输出端空气孔的数量增加而快速增长.在某一特定的缺陷长度时,谐振腔的品质因子达到极大值.这种谐振腔的波输出的方向固定在槽轴线的方向上.     

PVP辅助低温水相法制备Cu_2O微纳米颗粒及其光催化性能

采用表面活性剂PVP(聚乙烯吡咯烷酮)辅助低温水相法制备了氧化亚铜纳米颗粒,采用XRD、FE-SEM和UV-vis对其结构和形貌进行了表征,结果表明,PVP的用量是获得高质量、单分散微纳米颗粒和形貌控制的关键。以亚甲基蓝(methylene blue,MB)溶液的降解为探针,研究了八面体形貌氧化亚铜在模拟日光条件下的催化活性。     

一种复合型光子晶体微谐振腔

提出了一种基于介质基片上的周期性空气槽和一条有缺陷的线形周期性空气孔复合型二维光子晶体微谐振腔。利用FDTD方法对所提出的结构进行了数字模拟，模拟结果证实了这种结构在光子禁带区域内存在谐振模式，是一种有效的微谐振腔。这种微谐振腔的谐振波长主要由空气孔的周期和缺陷区的长度决定，而周期数量的多少对谐振波长的影响较小。当空气槽参数固定时，谐振波长与空气孔的周期成正比。在一定的范围内，谐振波长随缺陷区的长度增加而近似线性增加。谐振腔的品质因子随输出端空气孔的数量增加而快速增长。在某一特定的缺陷长度时，谐振腔的品质因子达到极大值。这种谐振腔的波输出的方向固定在槽轴线的方向上。     

泥岩水岩作用特性研究——以武汉市百瑞景工地志留系泥岩为例

为进行泥岩水岩作用特性研究,将武汉市百瑞景工地的志留系坟头组泥岩采样进行X射线衍射试验、干湿循环试验和不同pH值溶液试验,采用日本引进的SH-70软岩针贯入仪测得泥岩在不同环境中抗压强度,观察其完整性变化及崩解状况。试验结果表明,武汉市泥岩水岩作用机理以崩解和软化为主;抗压强度值与含水率有关,含水越高,抗压强度越低,反之则越高,且沿水平层面的抗压强度显著小于沿垂直层面的抗压强度;不同pH值溶液对泥岩水岩作用反应程度影响不同,随pH值减小,泥岩崩解性增加,抗压强度变小,且泥岩水岩作用对溶液pH值变化敏感程度酸性环境中比碱性环境中强,在工程中遇到酸性环境应及时采取措施进行治理。     

浅析影响路基稳定性的因素

路基结构直接暴露在大气之中,经受着自然环境因素的影响。温度和湿度是对路基路面结构有重要影响的自然环境因素。路基路面结构的温度和湿度状况随周围环境的变化而变化,路基路面体系的性质与状态也随之发生变化。路基土和路面材料的强度与刚度随路面结构内部温度和湿度的变化有时会有大幅度的增减。     

一些配位过渡金属或稀土连结的多钼酸化合物的合成、结构及性能研究（英文）

利用简单的手性有机配体L-酒石酸成功地合成出了一系列类似DNA螺旋构型的左、右旋的一维链状聚合物：{A[Mo2VIO4LnIII(H2O)6(C4H2O6)2]·4H2O}n (Ln = Sm, Eu, Gd, Ho, Yb, Y; C4H2O6 = L- 或 D-酒石酸； A = NH4 或 H3O)。通过水热法，巧妙地把传统的钼氧单核{MoO4}、双核{Mo2O7}以及{Mo8O26}等结构单元，通过有机配体配位的过渡金属单元交错地连接成零、一、二、三维的一系列结构新颖的化合物，这类化合物大多数具有可以容纳客体小分子的隧道或空穴，如 [Cu(4,4’-bpy)]2MoO4·2H2O，[Cu(4,4’-bpy)]2Mo2O7，[Cu(4,4’-bpy)(Hnic)(H2O)]2Mo8O26等。首次利用水热法合成出了含稀土的杂多酸类化合物，[Gd(H2O)3]3[GdMo12O42]·3H2O。该化合物是由Silverton-型的 [GdMo12O42]9- 阴离子和配位的Gd3+ 阳离子组成的。在[GdMo12O42]9- 离子中首次把顺磁性的钆(III)离子引入到该构型的中心，并且通过九配位的钆(III)离子把它们连接成具有介孔结构的三维网状化合物。该化合物的获得为今后合成类似化合物提供了一个很好的范例。在水热法合成出的化合物，[Cu2(C8H6N2)2(C7H6N2)]2[Mo8O26] 中，首次捕捉到喹喔啉的氧化产物苯并咪唑，证明了在水热条件下含氮的芳香杂环类的有机配体可以被二价铜氧化，其氧化产物进而作为配体直接与铜原子配位，最终形成新颖的上述化合物。     

Cracking the superheavy pyrite enigma: possible roles of volatile organosulfur compound emission

The global deposition of superheavy pyrite (pyrite isotopically heavier than coeval seawater sulfate in the Neoproterozoic Era and particularly in the Cryogenian Period) defies explanation using the canonical marine sulfur cycle system. Here we report petrographic and sulfur isotopic data (δ³⁴S_py) of superheavy pyrite from the Cryogenian Datangpo Formation (660–650 Ma) in South China. Our data indicate a syndepositional/early diagenetic origin of the Datangpo superheavy pyrite, with ³⁴S-enriched H₂S supplied from sulfidic (H₂S rich) seawater. Instructed by a novel sulfur-cycling model, we propose that the emission of ³⁴S-depleted volatile organosulfur compounds (VOSC) that were generated via sulfide methylation may have contributed to the formation of ³⁴S-enriched sulfidic seawater and superheavy pyrite. The global emission of VOSC may be attributed to enhanced organic matter production after the Sturtian glaciation in the context of widespread sulfidic conditions. These findings demonstrate that VOSC cycling is an important component of the sulfur cycle in Proterozoic oceans.     

Analysis of trajectory errors in integrating ordinary differential equations

A method of analyzing and interpreting trajectory errors in the numerical solution of ordinary differential equations by digital computers is discussed. Truncation in integrating a set of differential equations leads to errors in the trajectory of the solution. An explanation is given for the use of diagrams in the complex plane to evaluate errors in the trajectory, with a discussion of the properties of a number of frequently used integration formulas via the diagrams. The diagrams portray the characteristics of an integration method in more detail than do the absolutely stable regions presented by Dahlquist. Based on the diagrams, guidelines are listed as to how to choose a proper integration formula for the given set of differential equations. A method is presented to check whether or not the numerical solution is satisfactory.     

胡枝子种内地形梯度变异的分析

 Owing to the diagnostic characters used for distinguishing Lespedeza bicolor Turcz. from its allies L. formosa (Vogel) Koehne and L. elliptica Benth. ex Maxim. etc. beiny totally quantitative, and the great variability found in themselver as well, the group is therefore regarded as a taxonomically perplexing one. Therefore  quantitative measurements of the diagnostic characters, namely, the lengths of flowers (including standards and keels) and calyces (including calyx teeth and tubes) upon the total 307 herbarium sheets collected from 22 provinces and autonomous regions were made, and the data obtained were treated statistically (Table 1) and compared using methods of scatter diagram (Fig. 1--5),polygraph (Fig. 6) and topoclinal variation  (Fig. 7--10) in order to bring to light the differentiation pattern of these characters correlated to geographical distribution.      The diagrams of topoclinal variation (Fig. 7--10) of single characters represented by the lengths of calyx-teeth and corolla, or the calyx-teeth/calyx-tube ratio, between which exists a strong positive correlation, show a tendency of increasing gradation from northeast towards south-west. But the different combinations of morphological characters as shown in the scatter diagrams and more particularly in the polygraphs, make it possible to divide the Lespedeza bicolor group into the following three geographical types: (1) Bicolor type, with the distributional area of four provinces and one autonomous region of north-eastern and northern China; having the shortest (shorter than the calyx-rube) calyx-teeth of the whole group; with the standards of 71% herbarium materials exceeding the keels;  the  corolla length/calyx length ratio being 2.24; (2) Formosa type, with the distributional area covering six provinces and one autonomous region of eastern, south-eastern and southern China; with calyx-teeth nearly as long as calyx-tuges; with the keels of 69% herbarium sheets exceeding the standards, including all from whole  Guangdong  (Kwantung)  and  Guangxi (Kwansi); the corolla length/calyx length ratio being 2.59, the largest among the group; (3) Elliptica type, with the largest distributional area occupying ten provinces of south western, central, northwestern and eastern China and with most complicated morphologi- cal variation; the range of calyx-teeth length being 1.23--5.53 mm; with the keels of 80% herbarium sheets exceeding the standards, including all from whole Hubei (Hupeh) and Sichuan ( Szechuan ).      Since the above geographical types are either transitional or overlapping, it is probably appropriate to regard them as different geographical subspecies of a single species Lespedeza bicolor Turcz. Taxonomic treatments are then made herewith. A comparison of the main diagnostic characters and distributional patterns of the three subspecies in question is given in Table 3.     

On the Synthesis of Optimum Linear Feedback Control Systems

Standard forms are presented which define transfer functions for optimum type 1 and type 2 feedback control systems, where systems with minimum integral of time multiplied absolute value of error in the presence of a step displacement input are considered to be optimum. The ITAE criterion adopted in this paper was previously introduced by Graham and Lathrop.The optimization procedure leading to the standard forms presented here, is based upon an all digital simulation coupled to an unconstrained optimization algorithm to minimize the ITAE criterion value.It is shown with the aid of examples how actual systems can be compensated by use of appropriate standard forms to obtain optimum responses.     

一个含临界指数的拟线性椭圆型方程的注记

研究了如下的拟线性椭圆型方程:△pu+uq+λup*-1=0,u∈W1o,p(Ω), (1λ)其中,Ω2是RN中具有光滑边界的有界区域,△pu=div( |▽u|p-2▽u),N≥3,2≤p＜N,0＜q＜1,p*=NP/N-P.设λ*(Ω,p,q)是拟线性椭圆型方程(1λ)可解的参数集的上确界.运用变分方法,在不要求具有对称性质的一般区域Ω上得到了λ*(Ω,p,q)的一个可以精确计算的下界.     

A method for the closed-form evaluation of critical buckling loads for planar strongly curved bars

The calculation of critical buckling loads of planar curved bars, subjected to a general co-planar continuous external load (or a general co-planar terminal loading), leads to the solution of transcendental (nonlinear) equations. In this investigation a new method for the closed-form solution of such types of equations is presented. In particular, the transcendental equation u tan γ cot uγ = 1, corresponding to the buckling problem of a cantilever circular bar of high curvature loaded by two co-planar forces acting along its chord, is solved in a closed-form. Finally, several numerical results are presented, based on the Gauss integration rule.     

暗物质晕中星系的配置

基于杨小虎的博士论文《宇宙大尺度结构的统计研究》中第4部分内容整理缩写而成。讨论如何利用星系－星系的弱引力透镜观测来获得星系光度－暗物质晕质量之间的关系;并介绍建立的条件光度函数模型,在这个模型中我们预言了给定质量的暗物质晕中所能形成的不同光度的星系的概率。这些结果给出了讨论星系形成理论中各种物理过程的判据。基于这个模型还预言了一些宇宙中光的分布行为：如宇宙中超过一半的光是来自质量小于1012太阳质量的暗物质晕中。     

带Hardy-Sobolev临界指数和权函数的半线性椭圆问题的非平凡解

借助环绕定理和非线性分析技巧,研究如下一类带Hardy-Sobolev临界指数和权函数的半线性椭圆方程 - Δ u-μ u |x|2 =λu+K(x) |u|2*(s)-2u |x|s , x∈Ω; u=0, x∈Ω, 解的存在性,其中Ω是 R N具有光滑边界的有界开区域,0∈Ω,N≥5,0≤s≤2, 0≤μ≤ N-2 2 2, λ>０,K(x)是 上有界正函数.     

Citation influence for journal aggregates of scientific publications: Theory,with application to the literature of physics

A self-consistent methodology is developed for determining citation based influence measures for scientific journals, subfields and fields. Starting with the cross citing matrix between journals or between aggregates of journals, an eigenvalue problem is formulated leading to a size independent influence weight for each journal or aggregate. Two other measures, the influence per publication and the total influence are then defined. Hierarchical influence diagrams and numerical data are presented to display journal interrelationships for journals within the subfields of physics. A wide range in influence is found between the most influential and least influential or peripheral journals.