THE ALGORITHM OF COMPUTEROPTICAL-FIBERDIFFERENTIAL PROTECTION to show POSITIVE SEQUENCE FAULTED COMPONENT CURRENTS

Because of unsatisfied relaying protection of short transmission lines, a new differential protection system consisting of microcomputer and optical fiber channel has been presented in this paper. According to this system, a new algorithm including a differential criterion used for the positive sequence currents caused by faults and a difference-half cycle Fourier filtering method has been set up.     

Design of Cross Section Curves of Counter-intermeshing Twin-screw Kneader and Milling Cutters Blade Profiles

Basing on the theory of engagement, a design has been done for a new type of counter-intermeshing twin-screw kneader. Profile of the screw includes arcs and its envelope lines, and the profile is smooth and continuous without cuspidal points. Milling cutter blade profiles also have been calculated and corrected for manufacturing the helical parts designed and getting the clearance acquired. There may be interference between the cutter and the workpiece, so interference check must be done to insure the milling cutter and screw will not be interfered.     

A Numerical Method for Transmission Line Equations

Transient analysis of transmission line has recently been received more attention because operating speeds in high-speed digital electronics are increasing. Transmission line equations are hyperbolic partial differential equations, firstly this paper deduces how to change transmission line equations into quasilinear differential equations , thus the transmission line equation numerical result is gotten by computing the differential formation of quasilinear differential equations. The constraint of voltage and current is be considered and lumped equivalent circuit mode at boundary network collaborated at the same time in finding boundary conditions. Finally the paper computes transient response of transmission line with two typical boundary conditions. Numerical result shows that this approach is an effective way. It is explicit algorithm with less CPU consumption which can get time field response directly. The agree-upon effective way does be frequency field method, however it could not get time response unless the numerical inverse laplace transformation (NILT) be introduced. Thus this approach is more effective than FFT algorithm.     

Experimental Study of a Novel Detector''s Technique for Industrial X-ray Computed Tomography(CT)

Detector, influencing on system's performances, is one of some key techniques in x ray industrial computed tomography (CT) systems. Considering the existing problems for sensor (or detector) in CT systems, a new sensor is experimented by using optoelectronic integrated technique with optic fiber face plate optically coupling and transmission, and it is proved to be high integrated, high efficiency, high resolution, and low cost in industrial CT systems.     

One-loop Electroweak Radiative Corrections to Electron-positron Pair Production Via Two Photon Collisions

The authors calculate the cross-section with one-loop electroweak corrections to electron-positron pair production via two photon collisions in the standard model (SM), including virtual corrections and soft photon radiative correction. The relations between the cross-sections are discussed in tree level (and one-loop corrected cross sections) and center-mass energy in the luminosity measuring ranges of GLC. At last, the authors acquire the relation curves between differential cross section and the outgoing electron angle.     

Study on the Mechanism of Rockburst

Rockburst is often encountered in the underground engineerings of high geostress area, it is a kind of dynamic geodisaster.Depending on the examples of rockburst in the Erlang mountain highway tunnel and Jinping second powerstation tunnel, the fracture geometry shapes of rockburst are elaborated. Through the research of SEM analysis and rock mechanics tests of rockburst, three basic mechanics mechanisms of rockburst have been summarized,i.e., compression cracking, compression shear cracking,bending and breaking.     

Selection for grain yield of oats via vegetative growth rates measured at anthesis and maturity

Summary Grain yield of oats can be improved by increasing either vegetative growth rate or harvest index, but these two traits are negatively associated. Currently, harvest index of oats is near an optimum at 45%, so further improvement in grain yield must come from increased vegetative growth rate. In this study, vegetative growth rate was measured at anthesis and at maturity by dividing vegetative dry weight at anthesis and straw yield, respectively, by days to heading. Genotypic correlations between the two estimates of vegetative growth rate ranged from 0.53 to 0.66. When the highest 10% of the lines were selected for the two growth rate measurements, the actual genetic gain in grain yield was 3.5% when vegetative growth at anthesis was used, and a slight decrease occurred when vegetative growth rate at maturity was used. Selection for either growth rate measurement caused associated increases in biological and straw yields and dry weight at anthesis.Journal Paper No. J-12129 of the Iowa and Home Econ. Exp. Stn., Ames, Iowa 50011. Project 2447. Part of a study conducted by the senior author while a visiting scientist at Iowa State University.     

水稻种子耐干性机理的研究

以籼稻C38、粳稻京21、杂交稻秋优3为材料,进行种子超干储藏特性的研究,进而探讨种子耐干性的机理。通过超干水稻种子生活力和活力的比较,发现籼稻C38耐干性较强。超干有利于保持种子抗氧化酶系统的完整性,因此超干能提高种子的耐储性。对超干种子可溶性糖含量与组分进行分析,结果表明随着种子含水量的降低,蔗糖含量增高,多糖和葡萄糖含量降低,籼稻C38的蔗糖含量明显低于粳稻京21和杂交稻秋优3。用热重仪测定的种子含水量与烘干法得到的数据相吻合,用差示热量扫描仪测定束缚水/自由水的比例和玻璃化转变温度Tg,发现籼稻C38的Tg高于粳稻京21和杂交稻秋优3,籼稻C38束缚水/自由水比例大于粳稻京21和杂交稻秋优3,而束缚水/自由水的比例与耐干性成正相关。由此表明,耐干性在不同的水稻品种间有明显的差异,籼稻C38的耐干性较强。     

Positive Solutions of a Kind of Special Nonlinear Neumann Boundary Value Problems

The purpose of this paper is to consider a kind of special nonlinear Neumann boundary value problems. The kind of boundary value problems has not Green function. Using suitable transformation,we can change these problems to general Neumann boundary value problems. By applying integral equation and degree theory on cone,the existence of n positive solutions is proved for the kind of problems,where n is an arbitrary natural number.