伽罗瓦环上的一类No序列的构造

近年来,伽罗瓦环上的序列理论成为人们研究的热点问题.有限域上的No序列是一类伪随机序列,它在序列密码中占具十分重要的角色.本文利用伽罗瓦环上的置换,构造了伽罗瓦环Z_(p~e)上的一类新的No序列,并且研究了其线性复杂度.研究的结果表明此类No序列具有相当大的线性复杂度.     

Numerical methods for a fixed domain formulation of the glacier profile problem with alternative boundary conditions

In this paper we develop a set of numerical techniques for the simulation of the profile evolution of a valley glacier in the framework of isothermal shallow ice approximation models. The different mathematical formulations are given in terms of a highly nonlinear parabolic equation. A first nonlinearity comes from the free boundary problem associated with the unknown basal extension of the glacier region. This feature is treated using a fixed domain complementarity formulation which is solved numerically by a duality method. The nonlinear diffusive term is explicitly treated in the time marching scheme. A convection dominated problem arises, so a characteristic scheme is proposed for the time discretization, while piecewise linear finite elements are used for the spatial discretization. The presence of infinite slopes in polar regimes motivates an alternative formulation based on a prescribed flux boundary condition at the head of the glacier instead a homogeneous Dirichlet one. Finally, several numerical examples illustrate the performance of the proposed methods.     

太原一电厂汾河一坝西干渠扩建工程效益分析

文章介绍了从 1989年 10月至 1994年 5月 ,对汾河一坝西干渠陆续进行的改建和扩建工程 ,保证了渠道及建筑物工程运行正常 ,基本上满足工农业用水 ,收到了较好的社会效益和经济效益     

杂交茄子新品种“呼茄6号”的选育与试验

呼茄6号是以79B01-2-2-2为母本，9105-1-1-3为父本配制的一代杂种。该品种中早熟，始花节住7-8节果实长卵圆形，果皮黑色，光泽度好，耐弱光，果肉松软，味甜，口感极好。平均单果重量80g左右，露地每667m^2产量4400kg左右。适宜保护地和露地栽培。     

石嘴山一矿煤体结构变化的地质控制

采用反映煤体结构破坏程度的若干宏观与测试参数,研究了石嘴山一矿井田主采三层煤的煤体结构变化特征。揭示出三层煤体结构垂向变化的分层性主要受石嘴山向斜中和面所控制;煤体结构横向分区性主要受北西向缓波状褶皱所控制。研究还表明,三层煤煤岩组分的构成也对煤体结构类型的发育有一定影响。     

Definitive evidence that the ESR spectrum observed during photolysis of Mn2(CO)10 in THF is due to octahedral high-spin (d5) manganese(II)

The reassignment to a manganese(0) quartet state by C.L. Kwan and J.K. Kochi (J. Organometal. Chem., 101 (1975) C9) of the ESR spectrum obtained during photolysis of Mn₂(CO)₁₀ in THF is shown to be in error; computer simulation of the X-band spectrum and observation of the S-band spectrum confirm our previous assignment to sextet manganese(II) and chemical and IR evidence indicate the presence of [Mn(CO)₅]^? as a counter ion.     

张峰水库一干工程地质探研

通过对张峰水库一干工程的地质勘测,对干渠的地形地貌、物理地质现象、地层岩性、水文地质、地质构造及地震和工程区地质条件进行了分析与评价。     

香花槐组织培养及快速无性繁殖

以香花槐幼叶、幼茎为材料，材料经表面消毒后，接种到诱导培养基和继代培养基上，15－20天，形成愈伤组织，30－40天形成芽，50天左右，形成苗，截取无根苗到生根培养基上，15－20天后，形成根系。     

The gas phase structures of the isomers of benzene: IV. Hexafluoro-dewar-benzene

Gas phase electron diffraction data for HFDB were analyzed, following conventional procedures, and a structure was deduced for the perfluoro-bicyclo-[2.2.0]hexa-2,5-diene consistent with its C_2v symmetry. A least squares analysis of the molecular scattering function gave the following r_g values: [-C-C-] = 1.597 ± 0.006 Å, [C-C-] = 1.503 ± 0.002 Å, [-C-C-] = 1.356 ± 0.007 Å, [-C-F](bridge) = 1.331 ± 0.008 Å, [-C-F] (terminal) = 1.323 ± 0.004 Å. The flap angle between the rings is 115.3( ± .7)°. The terminal fluorines are in the planes of the corresponding rings.The most notable feature of the structure is the long C-C bridge bond, which was also observed in hexamethyl-Dewar-benzene. The geometrical features of HFDB are compared with corresponding ones in HMDB, and with perfluoro- cyclobutene as well as with theoretical estimates.