基于Washout滤波器的R(o)ssler系统Hopf分岔控制

针对R(o)ssler系统平衡点的Hopf分岔,以Washout滤波器为控制器,详细讨论了控制器参数对Hopf分岔点位置、分岔类型以及周期解振幅的控制问题.首先根据Routh-Hurwitz判据计算了受控系统的参数空间稳定域,找出了对应的Hopf分岔边界,并由此分析了滤波器时间常数、线性控制增益对分岔点位置的影响.然后,引入Normal Form直接法方便地求出系统Hopf分岔Normal Form系数,由此确定出改变分岔类型和周期解振幅的控制器非线性增益选择原则.最后用数值计算验证了本文的结论.     

3D激光扫描工艺与锦屏Ⅰ级水电工程右岸建基面绿片岩实测迹长分布研究

锦屏Ⅰ级水电站右岸建基面发育有大量的绿片岩,它们是水电站建设中重大工程地质问题研究中需要注意的对象之一。为了研究它们的迹长分布规律,利用3D激光扫描工艺,对锦屏Ⅰ级水电工程右岸建基面高差50m范围内的绿片岩出露区域进行了扫描,获得了准确的绿片岩出露的迹长数据,从而使绿片岩迹长分布研究成为可能。研究发现,迹长数据样本最集中分布于0~3m的区间; 随着迹长的增加,落在子区间内的条数(频数)递减; 在0~9m的各个子区间内,样本呈正态分布。整体而言,实测迹长样本数据服从对数正态分布。     

Fuzzy相似矩阵方程X2=X与最优模糊等价矩阵的存在性

在文［１］基础上,对Ｆｕｚｚｙ 相似矩阵方程Ｘ２＝ Ｘ 的解的结构进行了进一步研究。首先提出了Ｆｕｚｚｙ 等价标准型的概念,为解的表达提供了工具; 第二,指出了相应标准分解过程的参数系的唯一性; 第三,在群作用观点下和平移等价类的意义下,讨论了解的类数计算公式; 第四,给出了解的分类表达式; 最后,证明了“失真”最小的模糊等价阵,即Ｆｕｚｚｙ 最优等价阵的存在性,为Ｆｕｚｚｙ 聚类提供了理论依据     

Interfacial imperfection on reflection and transmission of plane waves in anisotropic micropolar media

This study is concerned with the reflection and transmission of plane waves at an imperfectly bonded interface between two orthotropic micropolar elastic half-spaces with different elastic and micropolar properties. There exist three types of coupled waves in xy-plane. The reflection and transmission coefficients of quasi-longitudinal (QLD) wave, quasi-coupled transverse microrotational (QCTM) wave and quasi-coupled transverse displacement (QCTD) wave have been derived for different incidence waves and deduced for normal force stiffness, transverse force stiffness, transverse couple stiffness and perfect bonding. The numerical values of modules of the reflection and transmission coefficients are presented graphically with the angle of incidence for orthotropic micropolar medium (MOS) and isotropic micrpolar medium (MIS). Some particular cases of interest have been deduced from the present investigation.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalysen der mer‐Trihalogeno‐tris‐Pyridin‐Osmium(III)Komplexe mer‐[OsX3Py3], X = Cl,Br, I

Synthesis, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analyses of the mer ‐Trihalogeno‐tris‐Pyridine‐Osmium(III) Complexes mer‐[OsX₃Py₃], X = Cl, Br, I By reaction of the hexahalogenoosmates(IV) with pyridine and iso‐amylalcohol mer‐trihalogeno‐tris‐pyridine‐osmium(III) complexes are formed and purified by chromatography. X‐ray structure determinations on single crystals have been performed of mer‐[OsBr₃Py₃] (monoclinic, space group P2₁/n, a = 9.098(5), b = 12.864(5), c = 15.632(5) Å, β = 90.216(5)°, Z = 4) and mer‐[OsI₃Py₃] (monoclinic, space group P2₁/n, a = 9.0952(17), b = 13.461(4), c = 15.891(10), β = 91.569(5)°, Z = 4). The pyridine rings are twisted propeller‐like against the N₃ meridional plane with mean angles of 49° (Cl), 46° (Br), 44° (I). Based on the molecular parameters of the X‐ray structure determinations and assuming C₂ point symmetry, the IR and Raman spectra are assigned by normal coordinate analysis. Due to the stronger trans influence of pyridine as compared with the halide ligands for N'–Os–X ^· axes significantly different valence force constants are observed in comparison with symmetrically coordinated octahedron axes: f_d(OsCl) = 1.74, f_d(OsCl^·) = 1.49, f_d(OsBr) = 1.43, f_d(OsBr ^· ) = 1.18, f_d(OsI) = 0.99, f_d(OsI ^· ) = 0.96, f_d(OsN) between 1.96 and 2.07 and f_d(OsN') between 2.13 and 2.32 mdyn/Å.     

Kristallstrukturen,Schwingungsspektren und Normalkoordinatenanalyse von cis-(Et4N)[OsF2Cl4] und trans-(Ph4P)[OsF2Cl4]

Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of cis -(Et₄N)[OsF₂Cl₄] and trans -(Ph₄P)[OsF₂Cl₄] By oxidation of the pure fluorochloroosmates(IV) with KBrF₄ or PbO₂/trifluoracetic acid in dichloromethane the mixed pentavalent complex anions cis-[OsF₂Cl₄]^– and trans-[OsF₂Cl₄]^– are formed. X-ray structure determinations on single crystals have been performed of cis-(Et₄N) · [OsF₂Cl₄] ( 1 ) (monoclinic, space group P2₁/n, a = 7.519(2), b = 17.648(2), c = 11.942(4) Å, β = 105.98(2)°, Z = 4) and trans-(Ph₄P)[OsF₂Cl₄] ( 2 ) (tetragonal, space group P4/n, a = 12.677(2), c = 7.743(1) Å, Z = 2). Based on the molecular parameters of the X-ray determinations and assuming C_2v point symmetry for the anion of 1 and D_4h point symmetry for the anion of 2 the IR and Raman spectra have been assigned by normal coordinate analysis. Due to the stronger trans influence of chlorine as compared with fluorine for F ^· –Os–Cl′ axes significally different valence force constants are observed in comparison with symmetrically coordinated axes: f_d(OsF ^· ) = 3.35, f_d(OsF) = 3.73, f_d(OsCl′) = 2.05 and f_d(OsCl) with 1.98 and 2.00 mdyn/Å.     

Darstellung,Schwingungsspektren und Normalkoordinatenanalyse der Halogenonitrosylruthenate [Ru(NO)ClnBr5–n]2–, n = 0–5, sowie die Kristallstruktur von (CH2py2)[Ru(NO)ClBr4]

Syntheses, Vibrational Spectra, and Normal Coordinate Analysis of Halogenonitrosylruthenates [Ru(NO)Cl_nBr_5–n]^2–, n = 0–5, and the Crystal Structure of (CH₂py₂)[Ru(NO)ClBr₄] By treatment of [Ru(NO)Cl₅]^2– with anhydrous HBr in dichloromethane a mixture of [Ru(NO)Cl_nBr_5–n]^2–, n = 0–5, is formed, from which individual complexes can be separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-Ray structure determination on a single crystal of (CH₂py₂)[Ru(NO)ClBr₄] (monoclinic, space group P2₁/c, a = 11.480(2), b = 10.175(4), c = 16.025(6) Å, β = 107.40(1)°, Z = 4) reveals, that the chlorine atom is trans positioned to the nitrosyl group. The low temperature IR and Raman spectra have been recorded of six complexes of the series (n-Bu₄N)₂[Ru(NO)Cl_nBr_5–n], n = 0–5, and are assigned by normal coordinate analysis. A good agreement between observed and calculated frequencies is achieved. The valence force constants are f_d(NO) = 13.86–13.93 und f_d(RuN) = 5.43–5.49 mdyn/Å.     

Fourier series based FE analysis of a disc under prescribed displacements–elastic stress study

This paper examines the numerical displacements and stresses developed around a disc under horizontal prescribed displacements and at the interface separating it from the surrounding elastic soil. Since the geometry of the problem exhibits axial symmetry and the loading is non-axisymmetric, the semi-analytical FE approach is used as it proves to be efficient and economical. First, both analytical and numerical expressions for soil reaction are established and compared. Results of comparison show a very good agreement. Then, for different values of the soil Poisson’s ratio, normal radial stresses, orthoradial stresses and shear stresses distributions along radial distance reaching 20r _d (r _d is the disc radius) are presented for a disc that has either perfectly smooth or perfectly rough interfaces with the elastic medium. The paper finishes by showing the effect of the soil Poisson’s ratio as well as the relative soil/interface stiffness on the stresses developed at the interface locations.     

人肝癌组织细胞的激光光镊拉曼光谱研究

激光光镊与拉曼光谱相结合形成的激光光镊拉曼光谱系统(LTRS)已用于分析生物组织标本,可对单个活细胞进行操控和光谱收集。从拉曼光谱特征峰位置、强度和线宽可得到有关细胞的组成、结构及细胞内物质相互作用的信息。文章应用LTRS系统,分析了来自人的恶性肝癌组织的不同病变部位标本,包括肝癌组织细胞、肝癌癌旁细胞和远离肝癌组织的肝脏正常的组织细胞,观察到了随肝癌的病变部位变化所出现的一些有趣的拉曼光谱峰的变化。正常的肝组织细胞在1 070和1 266 cm-1处的峰很明显,而肝癌和肝癌癌旁组织细胞的这两个峰则不明显,肝正常组织细胞的1 445 cm-1峰明显高于肝癌和肝癌癌旁组织细胞。已知1 070 cm-1峰代表脂类和核酸,1 266和1 445 cm-1峰代表脂类和蛋白。引起这些峰变化的物质很可能参与了肝癌的发生。上述初步研究结果表明：单细胞激光光镊拉曼光谱可以区分肝癌的不同病变部位,将是检测和分析肝癌组织标本的一种很好的方法。     

乙酰苯胺分子的拉曼、红外光谱和简正振动分析

分别在3 500～50和3 500～600 cm-1范围内实验测量了乙酰苯胺(ACN)分子的拉曼和红外光谱。运用密度泛函理论(DFT)采用B3LYP 混合泛函和6-311G(d, p)基函数组,计算了该分子的平衡构型和振动频率。结果表明：理论计算的分子最优化构型参数与以往文献报道的实验数据吻合,优于以往由6-31G(d)基函数组计算得到的参数;理论计算的振动频率值和本实验的观测值吻合得较好。运用简正振动分析方法得到了ACN 分子各振动频率的势能分布(PED),对ACN 分子的振动频率归属做出了全面、准确指认。