摘要:Based on Spurt’s embedding method and the author’s investigation results andexperiences, this paper introduces systematically the application process and key techniquesof orthoptera tibial organs. It discusses emphatically the testing key techniques and notes associated with the improvement of the sections’ quality. The excellent application results ofthe Spurr’s Embedding Method in the investigation of the orthoptera tibial organs areproved. The aim of the study is to scientifically spread and apply this international advancedhistological method and facilitate the functional and morphological investigation of the orthoptera tibial organs.
摘要:The Kinetics of basic copper (II) catalyzed polymerization of 2,4,6-tribromo-3-methylphenol is r= k1k2/k-1[2,4,6-tribromo-3-methylphenol] [CH3ONa][CuCl2] for low concentrations of copper(II) chloride, and r=k1k2/k-1 [2,4,6-tribromo-3-methyophenol] [CH3ONa](0.10-[CuCl2]) for high concentrations of copper(II) chloride ?The rate law obtained empirically is consistent with a reaction scheme in which a copper(II)-phenoxo complex is formed as a reaction intermediate ?The rate-determining step isreaction of 2,4,6-tribromo-3-methylphenolate with basic copper(II) complex, The rateconstants and active energies were calculated from the experiment.
摘要:In this paper, the stabilizing conditions of chemical thermodynamic systemswere directly obtained by having a discussion on the direction conditions of the commonchemical thermodynamic processes,then,from which and some basic formulas of chemicalthermodynamic the stabilizing conditions of bincry solutions and critical points were derivedrespectively through mathematical deduction.
摘要:This essay brievely explains the orientation effect of replacemen base, i. e,the replacement base consists of two groups, neighbour orientation base and intervalorientation baes, focusing on explaination of orientation effect with the modern theory ofresonance. That means that neighbour orientation base and interval orientation base can allbe considered as resonance body with resonance structure, among which three resonancestructures are leading contributors of variety of resonance, each of the three leadingcontributors of orientation base has a negative charge. That is why the favour-electricityreplacement effect happens to the neighbour or opposit parts. The neighbour or opposit partsof the leading contributors of the interval orientation base each has a positive charge, that iswhy the favour-electricity replacement effect chieflg happens to the interval part.In this essay, the author uses resonance theory to explain the orientation effect,different from the electronic-shift theory which is accepted by the textbooks.
摘要:In this paper,we have studied the teaching methods which to explain theorientation effects of exsting a substituent on benzene electrophilic substitution withelectronic effect and resonance theory and campared with their teaching effects. It shows thatthe effect explainning with resonace theory is better.
摘要:This paper uses the method of probability to solve a few valuable problems ofcommodity economy management how to arrange man power and thing power reasonable,bythe least place obtain the greatest advantage.
摘要:Alternate effect matrix theory is a kind of cykerneties which combined withdetermine quality are nation. If it can be used to resolve the problems of uafue informationthat is difficult to resolue with classical math methods. This article leads alternate effectmatrix theory to the category of math math cybernetics. In order to study and cmalyse theproblem of collefe education, it is proved that this theory is effective, practice and yelednotable results with a very important spread value.
摘要:This paper proves the laplacs transform of the circuit models RLC from time-domain to complex frequency domain in detail. The physics meaning and the method oflaplacs transform also is given in this axtide
摘要:The alternatve method is as follows:(1)Replace the capacitors and induitorsby their eguivalent generates. (2)Write the hybrid equations by the modified nodal analysis.(3)Invert the hybrid equations to obtain the state equations. The suggestd method is simplerthan the conventional systematic formulation of state eguations.
摘要:In this paper, a set of controlling system of no static difference be used ininverter-type CO2/MAG gas shielded arc-welding machine is desinged, what is adjusted byvoltuge and complex solution to the static characteristic and the dynamic characteristic of theweldiny source is obtained. The maximum short-circuit current is limited, the splashquanlity is reduced,and the welding formation is improved. In this paper,a set of PWMcontrol system driving wire feed that is adjusted no static difference by feedback is designed.For this reason,"the wire drive feed is smooth,accurate and reliable.
关键词:Inverters;CO2/MAG gas shielded welding;control system.u △u p = u2 j △u Iu n
摘要:They do not coincide generally in effect points between buayancy and thecentre of gravity of a body in float. It is easy to be misunderstood what are the balanceconditions. This paper points out that determine factor is the relative place of the centre ofgravity and the centre of stable inclination,instead the centre of gravity and buoyancy. Onlywhen the plance of the centre of gravity is lower than the centre of stable inclination,or equalto the latter, a body in float is in steady balance.
关键词:Centre of gravity;buoyancy;centre of stable inclination.
摘要:This paper introduces a new method of thermal analysis to determine composition of greyiron, which uses ordinary sample cups, the time of primary grain the time-plate from primary grain platform to eutectic and eutectic, the temperature differencebetween primary grain and eutectic and of cooling velocity are measured to determinedinstead of direct determination of TL’,TE’ to definite the chemical composition of grey iron.Not only the temperature pouring and condition cooling are considered, but also theinaccuracy of temperature measurment is avoided, the reliability and praticality of thermalanalysis is improved.The several mathematical models of CEV,C%,Si% are established.