Abstract:This work is one of the series，which studies the lepton identification in the BES (Beijing Spectrometer) in detail. The preliminary M.C. results about the discrimination between muon，electron and the other secondaries generated by hadron punch-through，especially by pion，are reported. The results show that there are two efficient cuts，i.e. the total charge Q and the second moment S for the discriminating of electron and pionin barrel shower counter，and there are also two cuts，i.e. position for direction for the discriminating of muon and pion in muon-system of BES. Thus the BES is of the good ability for the lepton identification.

Abstract:Initial parameters of detonation wave oblique reflection on a compressible metal plate have been computed in this paper. When the computation is made, five kinds of explosives: TNT(ρ₀:1.64g/cm³，1.45g/cm³),RDX (ρ₀:1.59g/cm³，1.76g/cm³，1.80g/cm³)、RDX/TNT(77/23) (ρ₀:1.75g/cm³),Pentolite (ρ₀ :1.65g/cm³，1.68g/cm³ )and B explosive，and three kinds of media; Fe, Cu and Al are selected.

Abstract:A multi-functional 1 2/2 D plasma simulation code is developed in this paper. The principles，methods and programming techniques are described. Finally，the applications of the electromagnetic simulation is discussed.

Abstract:Using the interaction potential between ions given by Gordon-Kim model，we calculated the thermal expansion coefficients of KCl and KBr crystals at room temperature，The results Were compared with experimental data.

Abstract:Polytitanocarbosilane(PTC)，the precursors of SiC fibers containing，Ti，was synthesized by the reaction between polycarbosilane (PC) and tetrabutoxititanium (Ti(OBu)₄). The structure and properties of PTC depend directly on the molar ratio of Ti(OBu)₄/PC. The spinnability and the melting point of PTC change regularly with this ratio. It is attributed to the formation of the crosslinked structure by-Ti-O-as bridge group and the pendant structure by-Ti(OBu)₃ as side group. The relation between structure and properties of PTC has been studied in this paper. SiC fiber containing Ti has been obtained from PTC-0.02 and PTC-0.04 with good spinnability as their precursors.

Abstract:Polytitanocarbosilanes (PTC)，the precursor of SiC fiber containing Ti，has been synthesized directly from polysilane (PS) and titanium tetrabutoxide (Ti(OBu)₄) without using any reaction promoter. In this reaction，PS was decomposed into polysilane of low molecular weight (LPS) containing Si-C skeleton and Si-H bonds. Then PTC was obtained by the reaction of Si-H bonds in LPS with Ti(OBu)₄ accompanied by the conversion of Si-Si skeleton in LPS into Si-C skeleton. In this paper，the synthesis process and structure of PTC-Ⅱ prepared by this new method，compared with PTC-Ⅰ obtained by old method，and the properties of SiC fiber containing Ti using PTC-Ⅱ as the precursor were examined and discussed.

Abstract:In this paper，the copolymers of 1,4-diethynylbenzene and 1,4-butynediol with various kinds of ratio and their homopolymers are synthesized using (Ph₃P)₂ PdCl₂ as catalyst. The copolymers are of blackbrown color，insoluble in benzene， CHC1₃，THF and ethyl alcohol and infusible until 350℃. The higher the ratio of DEB in copolymerization，the larger the density (d₄²⁵) of copolymers，the higher the yield of copolymers and the less the swellability (θp) and average molecular weights between crosslinks (Mc ). When DEB/BD≥1/2 (mole ratio of monomers)，the best solvent of copolymers is benzene and the solubility parameter(δp) is 9.15 cal^0.5?cm^-1.5，when DEB/BD=1/5，the best solvent of copolymer is ethyl alcohol and δp is 12.7 cal^0.5? cm^-1.5.IR spectra of homopolymers and copolymers are drawn and studied and reaction mechanism of copolymerization is suggested.

Abstract:The solubility of the ternary system of NiCl₂ -(CH₂)₆N₄?HCI-H₂O at 30℃ has been investigated by the phase-equilibrium method，the refractive indexes of the liquid phases have also been determined separately. The results show that the double salt which has the composition of 2NiC1₂ -(CH₂)₆N₄?HCl?9H₂O is formed in the cited ternary system. The thermochromic chracteristic of the equilibrium solid phase at 13℃ have been studied and its thermochromic mechanisms are inquired preliminarily.

Abstract:In this paper，polydiphenylbutadiyne (1) and phenylacetylenc-diphenylbutadiyne copolymer (2) are synthesised using (Ph₃P)₂PdCl₂ as catalyst. In the copolymerization，the best mole ratio of two monomers diphenylbutadiyne and phenylacetylene is 1/2. The catalytic homopolymerization of diphenylbutadiyne is superior to that of the thermal homopolymerization. According to infrared and ¹H-NMR spectra，the structure of polymer (l) and copolymer (2) may a11 be trans-transoidal configuration.

Abstract:The reason why H₂ can not be treated as the mixture of o-H₂ and p-H₂ is given. The correct method of explaining the residual entropy of H₂ from the definition of the spectroscopy entropy is presented.

Abstract:In this article a simple method is proposed，which can be used to estimate the energy efficiency of rocket propellants through the application of the values of bond energy of chemical bonds.

Abstract:The authors studied systematically the thermochromic properties of rare earth (RE) chelates of triphenylmethane complexons. The results show that the ligand structure is an important factor affecting the thermochromic properties and mechanisms. To research the relation between the ligand structure and thermochromic properties we studied in this paper the thermochromic characteristic of the RE(Ⅰ)-chrome azurol S chelates.

Abstract:Soluble dimethylsilane-diphenylsilane copolymer has been prepared by the reaction of a mixture of dimethyldichlorosilane and diphenyldichlorosilane with metallic sodium. The results show that the yield of copolymer increases when the ratio of these two monomers approaches unity，the molecular-weight decreases with the increasing of diphenyldichlorosilane content. The molecular-weight and composition of the copolymer are basically unrelated to the reaction time，but the yield increases with time at the beginning. Reaction temperature basically has no influence on the yield and molecular-weight of the copolymer. It also shows that the copolymer is amorphous.

Abstract:In this paper，the problems in measuring the parameters of grinding-in of the slide valve are theoretically analysed. The mathematical model of flow-displacement curve is deduced. A new way of fitting the theoretical formula to eliminate the errors in data processing is put forword. To estimate the radius of fillets and the radial clearance is especially important to the control of the machining quality of slide valve.

Abstract:This paper describes the measurement principle of grinding-in parameters of slide valves. The measurement system for the grinding-in parameters of slide valves controlled by a microcomputer is established. Hardware and softwave design for the system is introduced，the experimental results of measurement system are presented，the measuring errors of the system are analysed. Final1y，several conclusions are obtained.

Abstract:Based on the invariability principle of relative motion between two objects，a new method of analyzing kinematics of the planar complicated machanism has been presented in this paper. This new method can be used in drawing machanism chart and deriving the analytic expression among kinematic parameters. The method has been proved to be correct and effective by computer simulation.

Abstract:Theoretical and experimental research for improving the response of flow-sensor is presented in this paper. First the shortages of analogous compensation are pointed out. Then the identification and experimental method of f1ow-sensor are described. Final1y the digital compensation way for improving response of floW-sensor is established. The experiments are very effective.

Abstract:By dividing some kinematic pair from links，this paper has made a comprehensive dynamic analysis of a planar closed multiple mechanism，which may be used as a field robot's step-leg mechanism，and We have obtained a11 the input moment of the master crank and the constrained force in every kinematic pair in a period. All of these make it possible to control，drive and modify the robot's step-leg mechanism in future.

Abstract:Many methods of the steady state response of elastic mechanisms have been developed in recent years. As a trial，this paper proposed to adopt the method of weighted residue for the periodic response. And two basic algorithms and two examples are given. Between the two examples，the spatial four-bar RS'SR mechanism is new.