N-terminal of L protein of vesicular stomatitis virus contains a new signal sequence

The L protein (241kD) of vesicular stomatitis virus (VSV) is the most important snbnnit of the replication complex. The existence of specific localization signal in the L protein was investigated by making recombinant constructs expressing truncated mutants of the L protein fused to green fluorescent protein (GFP) in transient transfection assays. The chimeric genes encoding varied N-terminal of L and GFP gene were put under the control of T7 promoter or CMV promoter. The fusion proteins were transiently expressed in BHK-21, COS-7, CHO or Hep G2 cells. When more than 120 residues were deleted or only 96 residues were kept on the N-terminal, the fusion proteins were shown to be distributed throughout the cells, cytoplasm and nucleus under the confocal microscope. However, other chimeric proteins with 120 or more amino acids were dotted and distributed in the perinuclear regions. And the fusion protein with 96—120 aa has the similar distribution. A thirteen-residue peptide QGYSFLHEVDKEA (108—120) was identified as localization signal, whose function would be absolutely distributed with the deficiency of D or V. Our results show that there is an independent localizing signal in N-terminal domain of L protein of VSV and this functional signal is conserved in different cell lines.     

An iterative algorithm in potential-field inversion

1　Principle and MethodAll the problems of potential- field inversioncan be concluded that of solving nonlinear functionas follows:b =f( x) ( 1 )where x =( x1,x2 ,… .xn) T,xj( j =1 ,2 ,… ,n)indicate geometricparameters and physical parame-ters of the object;b=( b1,b2 ,… ,bm) T,bi( i=1 ,2 ,… ,m) indicate potential- field measurements.Main algorithms for expression( 1 ) are leastsquare method ( include damping least squaremethod ) ,gradient method ( conjugate gradientmethod and variable met…     

语音数据库标注系统的初步设计

此设计旨在完成语音数据库系统的语音标注工作，定义了标注件的格式和标注系统的主要功能。     

具有破产概率的企业股利贴现复合增长模型

企业具有破产概率对企业的内在价值有直接影响。在假定企业具有破产概率的条件下,建立破产分别出现在不同阶段时的两个股利贴现模型,可为投资者提供评价有破产可能的企业股票价值的理论依据。     

基于普通编码器的高精度位置检测方法

根据普通增量式光电编码器测量转角位置的原理，分析了量化误差的形成原因和编码器脉宽制造误差对测量精度的影响，提出了新的信号处理算法——脉冲细分法，利用该方法减小了量化误差．同时标定出编码器的脉宽系数井以它作为脉宽制造误差的补偿参数，消除对位置测量造成的影响，最终提高了系统的测量精度．     

数学新课程在西南地区适应性调查研究

数学新课程改革与实验顺利展开的关键在于全国统一性与地方多样性的有机协调和互动融合．为此，通过对西南新课改实验区管理者、教师、学生、家长及师范生的调查，初步解析了制约新课程实施过程中多样性和统一性有机协调的相关因素，诊断出数学新课程在西南地区的适应性水平，提出了相应的理论思考和实践建议．     

永磁非金属液体电磁泵磁场数值分析

将电磁泵体求解场域按二维平面场处理,考虑了外磁场对永磁体的磁化效应,用有限元法对永磁非金属液体电磁泵的磁场进行了数值分析,得到了该电磁泵气隙中的磁密曲线以及载流海水在气隙中流动所受到的电磁力.实验证明该数值分析的结果是准确的,这些数据为永磁非金属液体电磁泵的设计和应用提供了可靠依据,同时也说明了可用永磁体代替价格昂贵的超导磁体应用于非金属液体电磁泵的磁极设计.图7,参7.     

强连续余弦算子函数的不可约性

讨论了强连续余弦算子函数的不可约性及其共轭扰动余弦算子函数的不可约性,建立了以下两个结果:1)设(X,‖·‖)为Banach格,{C(t)}t≥0是正的强连续余弦算子函数,B∈B(X,XΘ)是一个正算子,那么,扰动余弦算子函数{CB(t)}t≥0是不可约的充要条件为:J={0}及J=x是仅有的满足C(t)J J,K(λ)J J的闭理想,这里t≥0,K(λ)=R(λ2,AΘ)B.2)设{C(t)}t≥0是Banach格上的具有生成元为A的正余弦算子函数,则以下论断等价:①{C(t)}是不可约的;② 0>0;③对λ>S(A),R(λ2,A)是强不可约的;④对λ>S(A),R(λ2,A)是不可约的.     

对我国生态环境保护的思考

论述了我国森林生态、农业生态、草地生态、水生态、矿产资源开发、生物多样性等方 面的生态环境保护的思路,讨论了生态环境保护的基本原则.     

长江口流速和悬沙垂线规律研究

根据长江口的实测水流流速、悬沙含量及其级配资料，分析了它们变化的规律性，并用通用公式进行了验证．从研究结果可以看出：实测资料与现有理论和经验公式的拟合程度较好；在相对水深η=0.4处的流速、悬沙含量及其级配与垂线平均值基本一致，因而可用η=0.4处的流速u0.4与含沙量S0.4来计算单宽输沙率．