On differential structures of polynomial spaces in control theory

A valuable number of works has been published about Hurwitz and Schur polynomials in order to known better their properties.For example it is known that the sets of Hurwitz and Schur polynomials are open and no convex sets.Besides,the set of monic Schur polynomials is contractible.Now we study this set using ideas from differential topology,and we prove that the space of Schur complex polynomials with positive leading coefficient,and the space of Hurwitz complex polynomials which leading coefficient having positive real part,have structure of trivial vector bundle,and each space of (Schur complex and real,Hurwitz complex) polynomials has a differential structure diffeomorphic to some known spaces.     

沤竹产物的性能表征

采用核磁共振碳谱、傅里叶变换衰减全反射红外光谱(ATR-FTIR)分析的方法,结合纺织标准GB/T 5889—1986,定性和定量地分析沤竹产物(简称竹束)的化学成分.通过光学显微镜和X射线衍射研究竹束的形态及结晶构型.通过热重(TG)分析研究竹束的热性能,并与竹子原料及纤维成品进行对比.此外,还研究了竹束对环境湿度的敏感性,包括吸水能力和吸湿放湿特性.研究结果表明,沤制工艺可以有效分解和去除竹子中的黏结物质,分离出竹束.所得竹束主要成分为纤维素、半纤维素和木质素,各组分质量分数分别为42.25%,35.61%,19.39%,与竹原料各组分质量分数有所不同.该竹束可作为竹纤维生物脱胶工艺中的半成品,为后道机械细化处理或酶处理提供原料基础.     

基于光束法自由网平差的无人机影像严格拼接

以稀少控制信息的无人机影像严格拼接为目的,引入光束法自由网平差的原理及计算过程,并推导了相应的误差模型.选择广东省增城市西部两条航带中的4张相邻影像进行试验,利用该方法,解决了在Google Earth中选择的控制信息精度不一致的问题.通过权值的选择,实现了带有坐标及投影信息的无人机影像严格拼接.分析了线元素、角元素与拼接误差的关系,为在稀少控制信息条件下影像的拼接提供理论依据.     

Finsler流形上取值于向量丛的调和形式

通过定义Finsler流形上取值于向量丛p-形式的整体内积和射影球丛纤维上的积分,得到相应的余微分算子.进而定义Finsler流形上取值于向量丛p-形式的Laplace算子,并证明它是自共轭的椭圆算子.最后证明当目标流形是黎曼流形时,调和映射和取值于拉回切丛的调和1-形式之间的等价关系.     

钢筋混凝土空心板梁加固及其有限元分析

为了研究既有桥梁的加固问题,建立了ANSYS的有限元分析模型。通过对实际桥梁的分析,分别用SRAP(一种高强软钢丝和氧化铝聚糖树脂砂浆)技术及CFRP法(碳纤维增强复合材料)、粘贴钢板法两种方案加固了空心板梁。在三种技术都满足加固要求的情况下,通过有限元分析得出:SRAP技术在改善梁的刚度,提高钢筋混凝土的承载能力,以及改善梁受力状况方面,效果都是最佳的。对实际工程中应用SRAP技术提供了重要的参考和依据。     

具有常余维数2k+7不动点集的(Z2)k作用

设(Z₂)^k作用于光滑闭流形Mⁿ上, 其不动点集具有常维数n-r, J^r_n,k是具有上述性质未定向的n维协边类［Mⁿ］构成的集合,
J^r_*,k=∑〖DD(〗〖〗n≥r〖DD)〗J^r_n,k为未定向协边环MO*=∑〖DD(〗〖〗n≥0〖DD)〗MO_n的理想. 通过构造MO*的一组生成元证明了J^2k+7_*,k(k≥5)由所有维数大于2^k+7且模2欧拉示性数为0的协边类及分解式中每个因子的维数都小于2^k的2^k+7维可分解协边类构成.     

常曲率空间的带有平坦法丛的子流形

本文通过对于子流形的第二基本形式的长度平方的Laplacian的讨论,得到了常曲率黎曼流形中带有平坦法丛的子流形为全脐点子流形的一个充分条件。并利用该条件将M.Okumura得到的结果推广到任意常曲率流形的情形。     

毛细管束流变模型内壁粘附力的测量及影响因素研究

所研制的毛细管束流变仪可应用于很低的流速条件下(u=0.2cm·s-1 )、牛顿流体通过内径 200~530μm毛细管内壁的粘附力(Fw)的测量。实验结果表明,流体在微米级毛细管流动过程中,内壁表面上的粘附力对流动阻力的影响是很大的。在不同条件下,粘附力的变化趋势不同,由实测数据按边界层理论讨论了流体流速(u)、毛细管内径(D)、毛细管长度(L)、实验温度(T)和流体粘度(η)对粘附力的影响,实验条件基本符合化学驱油的工艺条件,所以其结果对化学驱油机理的研究具有指导意义。     

Analytical Algorithms for the Blend Ratios by Fibre-bundle Tensile Curves Part Ⅲ： The Definition Method and the Relationships between the Blend Ratio and Tensile Parameters Calculated from Different Ways

The algorithms of the strength, work, modulus and percentage methods have been introduced and discussed in Part Ⅰ and Part Ⅱ of the series papers. As the following, the percentage-function calculation and the frequency-function calculation of the definition method are defined and developed in detail. Meanwhile, the Procedures to fred the tensile parameters are analysed experimentally and involve “ED” being the average values of the corresponding tensile parameters of each bundle tensile curve measured; “EC” being the tensile parameters obtained from the averaged experimental tensile curve; and “TC” being the parameters of the theoretical tensile curve according to the corresponding nominal blend ratio. The theoretical and experimental results indicate that the blend ratio estimated by the definition method from wool/polyester blended fibre bundles has a high correlation with the actual blend ratio though the variables to be known in this method are the most of all the methods and there exist the difficulty to solve fibre bundle tensile behaviour without fibre broken in accuracy and that there are high correlations between the EC and TC data and the tensile parameters should be calculated using the EC method rather than the ED method with the exception of the bundle initial modulus. The relationships between blend ratios and the tensile properties of blended fibre bundles can be used to select the optimum blend ratio of blended tops or yarns.     

5DFRXXL region of long myosin light chain kinase causes F-actin bundle formation

Long myosin light chain kinase （L-MLCK） contains five DFRXXL motifs with ability to bind F-actin. Binding stoichiometry data indicated that each DFRXXL motif might bind each G-actin, but its biological significance remained unknown. We hypothesized that L-MLCK might act as an F-actin bundle peptides by its multiple binding sites of 5DFRXXL motifs to actin. In order to characterize F-actin-bundle formation properties of 5DFRXXL region of long myosin light chain kinase, we expressed and purified 5DFRXXL peptides tagged with HA in vitro. The properties of 5DFRXXL peptides binding to myofilaments or F-actin were analyzed by binding stoichiometries assays. The results indicated that 5DFRXXL peptides bound to myofilaments or F-actin with high affinity. KD values of 5DFRXXL binding to myofilaments and F-actin were 0.45 and 0.41 μmol/L, respectively. Cross-linking assay demonstrated that 5DFRXXL peptides could bundle F-actin efficiently. Typical F-actin bundles were observed morphologically through determination of confocal and electron microscopy after adding 5DFRXXL peptides. After transfection of pEGFP-5DFRXXL plasmid into eukaryocyte, spike structure was observed around cell membrane edge. We guess that such structure formation may be attributable to F-actin over-bundle formation caused by 5DFRXXL peptides. Therefore, we suppose that L-MLCK may be a new bundling protein and somehow play a certain role in organization of cell skeleton besides mediating cell contraction by it kinase activity.