1990 Vol.8

Please wait a minute...


For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails

Select

RADIATION DAMAGE AND ANNEALING BEHAVIOR OF As2+ IMPLANTED SILICON LIN, FANG ZIWEI, XING KUNSHAN, NI BUSHAN, ZOU SHICHANG Journal of Applied Sciences    1990, 8 (1): 1-5.   Abstract （441）      PDF（pc） （1333KB）（122）       Knowledge map    Save The radiation damage and annealing behavior of <100> Si implanted with 500 keV As2+ and 250 keV As+ have been investigated. Experimental results show that the damage created by As2+ implantation is greater than that created by As+ implantation. After rapid thermal annealing, the complete recovery from crystal damage, high substitution and electrical activation of implanted atoms can be obtained for both the As2+ and As+ implantations. The carrier concentration profiles are different for the As2+ and As+ Implanted samples, which can be explained by the rapid diffusion of impurities resulting from the serious damage enhancement induced by As2+ implantation. Related Articles | Metrics | Comments（0）

Select

A STUDY ON THE ELECTRICAL PROPERTIES OF RUBIDIUM ACID PHTHALATE (RAP) CRYSTALS LIANG GUIJING, SHI ZIKANG, WANG LIQING, LIN YIDE, YANG TONGQIN, ZHENG XIUQIN Journal of Applied Sciences    1990, 8 (1): 6-12.   Abstract （447）      PDF（pc） （474KB）（120）       Knowledge map    Save Rubidium acid phthalate (EAP) is an ionic organic polar crystal. In this paper, its dielectric property, DC-conductivities, P-E curve, as well as light transmission have been comprehensively studied and some qualitative explanations have been conducted thereupon in accordance with the characteristics of its crystal structure. Related Articles | Metrics | Comments（0）

Select

DISCONTINUITIES OF E-PLANE STRIP WITH PARTIAL HEIGHT AND THEIR APPLICATION TO MILLIMETER WAVE FILTERS RONG AOSHENG Journal of Applied Sciences    1990, 8 (1): 13-18.   Abstract （350）      PDF（pc） （386KB）（77）       Knowledge map    Save An efficient technique for analyzing the discontinuities of the partial height E-plane strip is presented. The curves for the equivalent circuit parameters of the discontinuities are obtained, which are of great value to engineering. A Ka-band bandpass filter composed of E-plane strips with partial height, for the first time, is fabricated. The experimental results show that this configuration has good bandstop performance. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

Select

AN EFFECTIVE METHOD FOR PARAMETER OPTIMIZATION OF GP MODEL HAO YUE Journal of Applied Sciences    1990, 8 (1): 19-24.   Abstract （582）      PDF（pc） （383KB）（83）       Knowledge map    Save An effective method for optimal parameter extraction of GP models in bipolar integrated circuits is suggested, Emphasis is placed on processing the iterative equations of GP models, The purpose is to reduce the requirements of the algorithm for initial model parameters and node voltages, And the iterative procedures of solving nonlinear equations for determining intrinsic junction voltages are replaced by an improved method, The method that box constraints are transformed simply is analyzed, A watchdog algorithm is used to find the solution of the constraint problem, Experiments show that the method is very effective for optimal parameters of GP models. Related Articles | Metrics | Comments（0）

Select

THE PROPERTIES OF MAXIMAL PREFIX CODES AND ENUMERATION YANG YUECHI, QIU WEIDE Journal of Applied Sciences    1990, 8 (1): 25-30.   Abstract （523）      PDF（pc） （384KB）（112）       Knowledge map    Save The properties of maximal prefix codes are established in this paper. We prove that tho family of maximal prefix codes forms a free monoid under the language concatenation, operation. A recurrence formula for tho number of finite maximal prefix codes is given as follows: Let Gm denote the number of maximal prefix codes in which the length of words is equal to m or less than it, we have then Gm=1+Gm-1n Where n is the number of letters of alphabet X. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

Select

ON THE ESTIMATION OF THE DYNAMICAL ROTARY TORQUE OF MECHANISMS WITH AN ELASTIC BAR WU HONGZE Journal of Applied Sciences    1990, 8 (1): 31-35.   Abstract （465）      PDF（pc） （355KB）（101）       Knowledge map    Save According to the Lagrangian equation, this paper introduces the dynamical equation for the mechanisms with, an elastic bar. It 19 known that Hooke's law 59 tenable only for the static condition and the dynamical equation is a special case when both angular velocity and angular acceleration are always zero. Up-to-date, torque meters both in China and in other countries are based on Hooke's law, and they can not measure the dynamical rotary torque. This paper based on the dynamical equation describes the way to measure the dynamical rotary torque. The trouble in practice is how to determine the equivalent moment of inertia J and the viscous damping k. We use the technique of parameter estimation to solve this problem. Two computing approaches are discussed. The kernel of the whole matter is the least square method. At last, the optimal estimation of the dynamical rotary torque is given by computation. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

Select

A PLANARITY TESTING ALGORITHM OF HAMILTONIAN GRAPH HU MEICHKNG Journal of Applied Sciences    1990, 8 (1): 36-40.   Abstract （717）      PDF（pc） （342KB）（94）       Knowledge map    Save Planarity testing algorithm of graphs is a quite complex process. In this paper, we give a much simpler testing algorithm of the Hamiltonian graph. For the algorithms to test graphs for planarity, refer to the references. Related Articles | Metrics | Comments（0）

Select

THE INVESTIGATION OF ALGORITHM FOR THE SMALLEST WEIGHT SPANNING TREE IN LSI ROUTING XIE GUOPING, YAO LINSHENG Journal of Applied Sciences    1990, 8 (1): 41-46.   Abstract （458）      PDF（pc） （339KB）（68）       Knowledge map    Save In this paper, the smallest weight spanning tree in the non-oriented complete graph, which is usually encountered in IC's routing, is discussed. An algorithm for finding the smallest weight spanning tree is presented. It is called the upper-triangular-matrix algorithm (briefly as M-algorithm). The data structure that supports the algorithm is described. For the complete graph G(n, e), the complexities in computing and in storage of the M-algorithm are 0(n3) and 0(n2), respectively. For the same storage requirements, the M-algorithm is superior to Kruskal's algorithm in computing. Related Articles | Metrics | Comments（0）

Select

AN INVESTIGATION ON NEW HIGH SPEED CMOS LOGIC SERIES 74AC XU KANG, LIU YUANHUA, ZHU YONGJIN, ZHOU XINXIANG, ZENG YIANGSHOU, XU YUANSEN Journal of Applied Sciences    1990, 8 (1): 47-54.   Abstract （696）      PDF（pc） （1434KB）（109）       Knowledge map    Save The latest CMOS VLSI technologies have resulted in a new generation high speed logic circuit——2μm advanced silicon gate CMOS logic series 74 AC, with the operating speed, max. frequency as, well as load capacity equal to or even better than those of the advanced 3rd generation bipolar TTL 74 ALS, while still retaining the basic advantages of the CMOS IC. In this paper, the design, fabrication and main AC/DC characteristics of this new high spead logic 74AG are presented, emphasis being put on analyzing and discussing its performance as compared, to other logic series, particularly to 74ALS. The perspective of its further development is also given. Using this new high speed logic series 74AC to replace the 74ALS will not only greatly reduce the total power dissipation of a high speed electronic system, but will also develop a new application field which is impossible to realize with the present 74 ALS, LS or 74HC. Its potential of further development seems to be quite great. Related Articles | Metrics | Comments（0）

Select

X-RAY DIFFRACTION STUDY ON THE RELATIONSHIP BETWEEN THE DEHYDRATION TEMPERATURE OF GOETHITE AND THE STRUCTURAL CHANGES OF HEMATITE CHEN JIZHOU, JIANG SHICHENG, WANG JIALIN, WANG JUNQIAO Journal of Applied Sciences    1990, 8 (1): 55-60.   Abstract （667）      PDF（pc） （1421KB）（99）       Knowledge map    Save In the X-ray powder diffraction patterns of hematite, formed by the dehydration of goethite, there are two markedly different groups of diffraction lines. One is comparatively sharp, whilst the other is rather diffuse. For the former, the line broadening effect is mainly dependent on the rearrangement of the oxygen Ions during phase change. For the latter, broadening of the line is related to the migration and rearrangement of the ferric ions. The present paper discusses in detail the βcosθ/λ~sinθ/λ curves of these two groups of diffraction lines, the mean crystallite size D, and the lattice deformation|(Δd)/d|.In the data treatment, two formulae are proposed to replace Jones' corrected curves for the facilitation of computerisation. Furthermore, on the surface of the dehydration product at 250℃, S-shaped fractures are observed by the electron microscope. The origin of this phenomenon is discussed from the structural view of goethite. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

Select

A MÖSSBAUER SPECTROSCOPY STUDY OF Ni-Fe-Mo ELECTRODEPOSITED ALLOYS WITH HIGH PERMEABILITY MENG QINGGANG, CHANG RUQIN, JIN HUIJUAN, XU GUIQIN, FENG LIQUN Journal of Applied Sciences    1990, 8 (1): 61-66.   Abstract （399）      PDF（pc） （388KB）（74）       Knowledge map    Save Soft magnetic alloys of Ni-Fe-Mo are electrodeposited from ammoniacal baths containing complexing agents of sodium citrate and sodium pyrophosphate. Mössbauer spectroscopy has been used to study the magnetic texture of the electrodeposited alloys. An experiment and a calculation method of determining the preferential orientation of Fe atom magnetic moment on condition that there is the lower internal magnetic field are given. It is found that sodium citrate has a significant effect on the orientation of the Fe atom moment. The influence of the magnetic texture in the electrodeposited alloys on the magnetic properties is also discussed. Related Articles | Metrics | Comments（0）

Select

SIMULTANEOUS THERMAL ANALYSES OF γ-Fe2O3 MAGNETIC POWDER IN HEAT TREATMENT PROCESS CUI BAOYI, YANG ZHIJUN, YAO KANYI Journal of Applied Sciences    1990, 8 (1): 67-75.   Abstract （428）      PDF（pc） （3566KB）（95）       Knowledge map    Save The most common process for making acicuiar particles of γ-Fe2O3 from hydrated ferric oxide α(FeO) OH involves three steps dehydration → reduction → oxidation. Mechanisms of the porefilling and the densification in the process of dehydration and conditions of phase transformation in reduction and oxidation periods have Loon investigated by means of simultaneous thermogravimetric and differential thermal analyses from the energy point of view on purpose to obtain the ideal technologicas process of heat treatment. The dense product of γ-Fe2O3 and coating with fewer porel and superior magnetic properties were obtained by the technological process which is better than the traditional one. Related Articles | Metrics | Comments（0）

Select

STUDIES IN CONTROLLING THE LENGTH OF α-FeOOH Effect of dispersers on the formation of α-FeOOH GUAN YOUSHENG, JIN XIN, ZHU YUNYIN, WANG GUANG, QU JIANYING, HUAO LI, MA SIYUAN Journal of Applied Sciences    1990, 8 (1): 76-80.   Abstract （568）      PDF（pc） （2239KB）（94）       Knowledge map    Save Sodium oxyalate and sodium hexametaphosphate were used as dispersing agents in the preparation of geothite (α-FeOOH). The experimental results showed that the dispersers had the effect of shortening the reaction time, promoting the geothite particle uniformity, preventing the denlrites in the geothitae growth process, and controlling the length of geothite. Related Articles | Metrics | Comments（0）

Select

CALCULATION OF MODE FIELD RADIUS AND SPLICE LOSSES IN BOW-TIE FIBER WITH ELLIPTICAL GAUSSIAN FIELD APPROXIMATION HE ZHIJIAN Journal of Applied Sciences    1990, 8 (1): 81-84.   Abstract （484）      PDF（pc） （224KB）（74）       Knowledge map    Save In this paper, a scalar variation analysis based on elliptical Gaussian field approximation of the fundamental mode of bow-tie fiber is presented. The mode field radii with, various structures are obtained. And also, the relations between the mode field radius and various splice losses of bow-tie fiber are shown in this paper. Related Articles | Metrics | Comments（0）

Select

OPTICAL FIBER TEMPERATURE SENSOR FOR MEDICAL USE TEMPERATURE MEASUREMENT SYSTEM IN GANGER TREATMENT BY MICROWAVE RADIATION SHEN ZHONGYAO, ZENG XIAODONG, GUO YIJI Journal of Applied Sciences    1990, 8 (1): 85-87.   Abstract （489）      PDF（pc） （191KB）（113）       Knowledge map    Save We have developed a new optical fiber temperature sensor for biomedical application, especially for temperature measurement in cancer treatment by microwave radiation. The experiments and clinical practice have shown that the optical fiber temperature measurement system is almost unaffected by the microwave radiation field. It can measure the temperature of the tissue which is heated by microwave radiation and it has come up to the requirements of clinical practice. Related Articles | Metrics | Comments（0）

Select

PRINCIPLE AND APPLICATION OF SMOOTH SPLINE METHOD USING SECTION-COORDINATE ROTATION WANG SHAOPING, JIANG PEIZHENG, GU CHUANGANG, MIAO YONGMIAO Journal of Applied Sciences    1990, 8 (1): 88-90.   Abstract （492）      PDF（pc） （200KB）（85）       Knowledge map    Save A new method for solving the large deflection curve by using the section-coordinate rotation approach is presented in this paper. The present method in suitable for derivation, interpolation and integration of enclosed curves and unenclosed curves with both y'>>1 and y'<<-1. The method has been applied to the design of three-dimensional impellers and the smooth treatment of the indicator diagram of the internal combustion engine. Results show that the present method is satisfactory. Related Articles | Metrics | Comments（0）

Select

OPTIMAL DESIGN AND MANUFACTURE ANALYSIS OF HIGH-VOLTAGE PLANAR DEVICES DENG BEI, BAO ZONGMING Journal of Applied Sciences    1990, 8 (1): 91-94.   Abstract （324）      PDF（pc） （281KB）（57）       Knowledge map    Save This paper presents a numerical analysis of high-voltage planar silicon devices having field limiting rings. The two-dimensional Poisson equation is solved by using the finite difference method. The effects of surface charges, substrate impurity concentration and junction depth are described. Methods of overcomingthese influ ences in optimal design are put forward. Strict control of junction depth in manufacture is a very important key for guaranteeing the high-voltage capability. Related Articles | Metrics | Comments（0）

Select

“ZOU MODEL” OF EL2 DEFECT IN GaAs in memory of Prof. Zou Yuanxi WANG GUANGYU Journal of Applied Sciences    1990, 8 (2): 95-102.   Abstract （557）      PDF（pc） （689KB）（134）       Knowledge map    Save Prof. Zou Yuanxi had explored the nature of some native derects in compound semiconductors by means of physicochemical method over 20 years. We sincerely introduce his science ideas and profound fruits in the identification of EL2 (the most important deep level in GaAs) in this paper,and express to cherish our deep memory of him. Related Articles | Metrics | Comments（0）

Select

THE PRESSURE EFFECT OF THE NiCr-NiSi THERMOCOUPLE AT LOW TEMPERATURE HUANG TONGKAI, GU JINMO, JIN BIANJIN Journal of Applied Sciences    1990, 8 (2): 103-106.   Abstract （524）      PDF（pc） （303KB）（89）       Knowledge map    Save We measured (1) the thermo-emf of the NiCr-NiSi thermocouple at various temperatures and (2) the pressure effect on the thermo-emf of this thermocouple at room and liquid nitrogen temperature up to 18 kilobar. A method of pressure-emfcorrection was given. Related Articles | Metrics | Comments（0） Cited: Baidu(4)

Select

LASER SELECTED IONIZATION OF Rb AND MEASUREMENT OF ISOTOPE SHIFT ON Rb LU YIQUN Journal of Applied Sciences    1990, 8 (2): 107-111.   Abstract （510）      PDF（pc） （321KB）（84）       Knowledge map    Save In a heat pipe furnace, Rb atoms, pumped by two-photon Doppler tree absorption (760.1 nm), are excited from the ground state 5S1/2 to state 7S. Then the atoms are excited to the ionization state by Nd·YAG laser. The signals of the ions of Rb are amplified by the look-in amplifier and then enter the x-y record. Selected ionization signals of Rb85 and Rb87 are observed, and the isotope shift of Rb(7S) is obtained. The super-fine structure of Rb (5S→7S) has also been observed. Related Articles | Metrics | Comments（0）

Select

NEW Q ENHANCED SWITCHED-CAPACITOR FILTERS WU JIE Journal of Applied Sciences    1990, 8 (2): 112-116.   Abstract （431）      PDF（pc） （283KB）（71）       Knowledge map    Save A new Q enhanced technique is presented, and two new switched-capacitor filters based on the technique are proposed. Design equations and optimal solutions for capacitor spread are obtained. Computation shows that the capacitor spread for the proposed circuits can be significantly reduced. Related Articles | Metrics | Comments（0）

Select

SURFACE LATERAL ELECTRIC FIELD FOR LDD MOSFET AND ITS APPLICATION CHEN XIAO, EUAN GANG, ZHANG QIANLING Journal of Applied Sciences    1990, 8 (2): 117-125.   Abstract （800）      PDF（pc） （582KB）（219）       Knowledge map    Save In this paper, an analytical model of the surface lateral electric field for LDD MOSFET is presented. This model contains geometric and doping parameters of LDD MOSFET. It can be used to calculate the surface lateral electric field of LDD MOSFET which has lightly doped drain regions of different lengths, junction depths and doping concentrations, Using this model, the electric field of the conventional and graded drain MOSFET can also be calculated. The result obtained from this model is identical with the numerical result of FD-MINIMOS. This model can also be applied to calculate the substrate current and breakdown voltage. According to this model, the optimal geometric and doping parameters can be easily determined. The present model provides a fast method for extracting the related parameters and is a convenient tool for the LDD MOSFET design. Related Articles | Metrics | Comments（0）

Select

A METHOD FOR THE DETERMINATION OF ENERGY GAP IN Si TRANSISTOR ZHEN JIANG, FONG YAOLAN, WEI TONGLI Journal of Applied Sciences    1990, 8 (2): 126-130.   Abstract （682）      PDF（pc） （317KB）（103）       Knowledge map    Save Energy gap is one of the most important physical parameters in Si transisitors. Based on the temperature dependence of the part of the reverse diffusion current in the emitter and the forward voltage of the collector-base PN junction, a new method for the determination of energy gap in regions of the Si transistor is presented in this paper. Because of the heavy doping effect, the carrier's Femi-Dirac statistical distribution is considered. The method only requires measurement of the temperature dependence of the DO parameter; therefore the result is accurate. Related Articles | Metrics | Comments（0）

Select

THE PRECIPITATION OF γ' PHASE IN ELINVAR ALLOY BY MOSSBAUER EFFECT QIAN XIANGRONG, CHEN FUSHI, JIN HUIJUAN Journal of Applied Sciences    1990, 8 (2): 131-137.   Abstract （5584）      PDF（pc） （2213KB）（146）       Knowledge map    Save The Mössbauer spectra of Ni42CrTi Elinvar alloy in quenching, aged and cold-working states are measured respectively. On the basis of the spectra, the distributions of internal fields are calculated. The experimental P(H) curves spread widely and are decomposed into three Gaussian curves, which represent three preferential configurations of iron atoms. The variation in internal fields can be referred to the precipitation of γ' phase in the alloys, which results in the variation in the neighbouring environment of iron atoms. Comparing the relative areas under the probability peaks at different internal fields in P(H) curves, the relative amounts of γ phases in different states of alloys can be deduced. In addition, the intensity ratio of the components of Mössbauer spectrum indicates the extent of preferential orientation of magnetic moments. Related Articles | Metrics | Comments（0）

Select

SYNTHESIS, PROPERTIES AND BIOMEDICAL APPLICATION OF SEGMENTED POLYETHER URETHANE EXTENDED WITH DIOL HUANG ZUXIU, FENG XINDB Journal of Applied Sciences    1990, 8 (2): 138-144.   Abstract （481）      PDF（pc） （441KB）（83）       Knowledge map    Save A series of segmented polyether urethanes (SPEU) were synthesized from 4, 4-diphenylemthane diisocyanate (MDI), polytetramethylene glycol (PTMG) and low molecular weight diols as the chain extender by the two-step solution polymerization with a mixture of dimethyl sulfoxide (DMSO) and methyl isobutyl ketone (MIBK) as the solvent. The effect of the reaction temperature on the intrinsic viscosity of the SPEU was studied. There was a slight change in viscosity of the polymers in the reaction temperature range of 60~110℃. The high molecular weight polymers without crosslinking were obtained by using a lower reaction temperature (at about 60℃). The effects of the structure and amount of the chain extender on the mechanical properties of the SPEU were discussed. Some of them can be used in the balloon of the Intra Aortic Balloon Pump (IABP) which exhibited excellent mechanical properties and blood compatibility. Related Articles | Metrics | Comments（0）

Select

STUDY ON THE PHASE-SEPARATION OF EPOXY RESIN TOUGHENED BY MULTI-FUNCTIONAL RUBBER LI SHANJUN, WANG HONGBIN, YE JINYONG Journal of Applied Sciences    1990, 8 (2): 145-150.   Abstract （421）      PDF（pc） （3647KB）（87）       Knowledge map    Save The morphology and process of phase-separation of toughening epoxy resin with epoxy-functional poly(n-butyl acrylate) (ETPnBA) and carboxy-functional poly (n-butyl acrylate) (CTPnBA) rubbers were studied by the optical microscope. The effect of curing conditions and prereact time of rubber and epoxy resin on the phase-separation were investigated. The control of the phase-separation and the mechanism of the phase-separation of the modified epoxy resin (by ETPnBA and CTPnBA rubbers) were discussed. Related Articles | Metrics | Comments（0）

Select

SEPARATION OF WATER-ETHANOL MIXTURES BY PERVAPORATION THROUGH CELLULOSE ACETATE MEMBRANES WU BINGKUN, SHI YANQIAO, ZHANG SHIMIN, CHENG GANJU, OHEN GUANWEN Journal of Applied Sciences    1990, 8 (2): 151-157.   Abstract （523）      PDF（pc） （1330KB）（84）       Knowledge map    Save In this paper, the cellulose diacetate (CA) dense membrane, CA reverse osmosis (RO) membrane and cellulose triacetate (CTA) dense membrane were used for the separation of water-ethanol mixtures by pervaporation (PV). The effect of acetyl group contents and the membrane morphology on PV characteristics are discussed. For CA and CTA dense membranes, the total flux (J) and the water-ethanol selectivity coefficient (α) vary with feed compositions in the same way. But for all the feed compositions the J of the CTA dense membrane is slightly higher than that of the CA dense membrane. The J and α of the CA RO membrane vary with feed compositions in the opposite way as the CA dense membrane does. Related Articles | Metrics | Comments（0）

Select

THE RESEARCH ON ELECTRICAL AND HYDRAULIC CONTROL FOR A TRIAXIAL TESTING DEVICE CHEN XIAOGUANG, XIU GUANGGENG, PAN GUODONG, WANG SHUHAI Journal of Applied Sciences    1990, 8 (2): 158-164.   Abstract （452）      PDF（pc） （451KB）（74）       Knowledge map    Save In this paper, a multi-purpose triaxial testing device is described. The device, controlled by a computer, is able to control loads in three dimensions independently. The deformation of the specimen is monitored by the grating type displacement transducers. Their counting numbers could be sampled at the same time. Related Articles | Metrics | Comments（0）

Select

THE TEMPORAL PREDICATES-EVENTS NETS WITH CONFIDENCE The Earthquake Forecast and Decision Model ZHANG YULI, YIN BAIWEN Journal of Applied Sciences    1990, 8 (2): 165-169.   Abstract （446）      PDF（pc） （317KB）（92）       Knowledge map    Save According to the requirements of earthquke forecast decision, and using the survey of Petri nets and the knowledge representation of essential entities and inferences of temporal logics, we propose the model of temporal predicates-events nets with confidence. It can express, imply and verify the causality of manifold elements, and can process concurrently and dynamically also. Furthermore, this model can be applied to other forecast and decision problems, such as those in military affairs, meteorology, marketing, etc. Related Articles | Metrics | Comments（0）

Select

DIRECT METHODS FOR MONOTONE DECOMPOSITION OF BOOLEAN FUNCTIONS (Ⅱ) LIU YONGCAI Journal of Applied Sciences    1990, 8 (2): 170-176.   Abstract （520）      PDF（pc） （386KB）（75）       Knowledge map    Save For those Boolean functions which can be monotonically decomposed, we present two classes of direct methods for monotone decomposition again in this paper. The first class of methods is available for canonical product of sums form and the second one is available for arbitrary boolean expressions. They also can be performed on computers easily. Related Articles | Metrics | Comments（0）

Select

TEMPERATURE DEPENDENCE OF A POLARON IN SEMI-INFINITE POLAR CRYSTAL ZHAO XUNJIE, GU SHIWEI Journal of Applied Sciences    1990, 8 (2): 177-180.   Abstract （464）      PDF（pc） （232KB）（71）       Knowledge map    Save Taking into account the interaction of an electron with both Lo and So phonons as well as the image potential at finite temperature, we study the effective Hamiltonian of a polaron in a semi-infinite polar crystal. The temperature dependence on the self-induced polaron potential, the effective mass and the depth of the dead layer is given. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

Select

NUMERI CAL CALCULATION FOR STATIC PERMANENT MAGNETIC CIRCUIT XU SHUJUN, SHI TAIHUA Journal of Applied Sciences    1990, 8 (2): 181-184.   Abstract （445）      PDF（pc） （241KB）（68）       Knowledge map    Save Up to now, the empirical formula is usually used to design the permanent magnet design. Because of the nonlinear characteric of the material, the design formula is difficult to correct; it is only a simplified approximation. The error may be great, which will cause heavy economical less, if expensive permanent materials, such as the rare earth permanent material, are used. This paper describes the result of the numerical calculation method for such a problem. This method can select the optimum working condition, and by making a reasonable compromise, good performance can be got at a lower cost. The authors calculated a magnetic circuit used for a moving-coil meter and obtained results which agree with the measured values. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

Select

THE DETERMINATION OF PSEUDO-KOSSEL DIFFRACTION INDICES BY SIMULATION METHOD ZHANG JIANZHONG, FAN DEPEI, ZHOU BING Journal of Applied Sciences    1990, 8 (2): 185-188.   Abstract （422）      PDF（pc） （1093KB）（77）       Knowledge map    Save The X-ray pseudo-Kossel diffraction indices of crystals can be determined on a large scale by using a simulation method, which is capable of indicating the indices of complete, incomplete or even severely broken.lines. By means of this method, the diffraction patterns could be made full use of and the standard diagrams of pseudo-Kossel diffraction can be offered. Related Articles | Metrics | Comments（0）

Select

IMPROVED STAIRCASE APPROXIMATION ANALYSIS OF RADIALLY INHOMOGENEOUS FIBERS XU SHANJIA, MA ZHEWANG Journal of Applied Sciences    1990, 8 (3): 189-196.   Abstract （430）      PDF（pc） （492KB）（88）       Knowledge map    Save In this paper, an improved staircase approximation method for analysing radially inhomogeneous fibers is advanced. This method combines the concept of the transmission line network with the rigorous mode matching procedure, and a new solving formula is obtained. Thus the procedure of the classical staircase approxi-mation is tremendously simplified. The analyses and computations of the dispersion, the Poynting flux distribution, the group velocity and the differential group delay for several representative radially inhomogeneous fibers of practical interest show that the present method is more succinct, more accurate and more rapidly convergent than the previous staircase approximation method. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

Select

APPLICATION OF THE HIGH TECHNOLOGY OF ULTRA-TRACE DETECTION BY RIS-TOFMS IN GEOLOGICAL PROSPECTING CHEN DIEYAN Journal of Applied Sciences    1990, 8 (3): 197-206.   Abstract （412）      PDF（pc） （723KB）（110）       Knowledge map    Save A combination of Resonance lonization Spectroscopy and Time-of-Flight Mass Spectroscopy (RIS-TOFMS) is the newest and most sensitive method in modern ultra-trace detection. This paper first presents a short account ef the basic principles of RIS-TOFMS and its current applications. Then the application of RIS-TOFMS to geological prospecting of underground concealed ores of precious metals is discussed in detail, followed by a description of the progress of our laboratory work. From the achievement and development of our work in recent years, we believe its prospect of practical development is bright. It will (1) Develop new instrument and equipment f or prospecting and surveying underground concealed ores of rare and noble metals and rare-earth metals; (2) Develop effective ship-born instrument and equipment for prospecting undersea mineral deposits; (3) Develop into a high-tech research method in materials science (including super-conduction), thin film science, environmental science, biology, medicine, etc. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

Select

INVESTIGATION OF DEFECTS INDUCED BY HIGH FREQUENCY IN PECVD PASSIVATION FILM LI DANZI, ZHAO LENGCHU, LAO FENGYING Journal of Applied Sciences    1990, 8 (3): 207-212.   Abstract （440）      PDF（pc） （408KB）（116）       Knowledge map    Save On the basis of experiments and theoretical analysis, the paper presents two kinds of defect as induced by high frequency in the PEOVD passivation films by using the parallel plate mode plasma equipment. One is the positively charged centre. It arises from the break of Si-O and Si-Si bands. The other one is the negatively charged centre which arises from the existence of ionogens, mainly (Si-H)Nx. Both of them can be eliminated by annealing at some proper conditions. Related Articles | Metrics | Comments（0）

Select

AN EXTRACTION METHOD OF PARASITIC SOURCE/DRAIN RESISTANCE AND EFFECTIVE CHANNEL LENGTH SUN XINGCHU Journal of Applied Sciences    1990, 8 (3): 213-217.   Abstract （581）      PDF（pc） （299KB）（119）       Knowledge map    Save Presented here is an accurate extraction method of parasitic source/drain resistance and effective channel length for MOSFET. The determination of these parameters is important to device modeling and analysis, and the fabrication process control. A special group of test devices was designed and a computer program was used for the parameter extraction procedure. The drain current characteristics of the devices were calculated by using the extracted parameters and compared with the measured data. The results showed a good agreement. Related Articles | Metrics | Comments（0）

Select

AN INFINITE TRIANGULAR CRACK UNDER MODE Ⅱ AND MODE Ⅲ LOADINGS XU LINLIN, OUYANG CHANG Journal of Applied Sciences    1990, 8 (3): 218-222.   Abstract （505）      PDF（pc） （274KB）（94）       Knowledge map    Save This paper is the continuation of the study of an infinite triangular crack In an infinite elastic solid, in which the singular stresses for mode Ⅱ and mode HI crack problems are obtained. It is shown that they have the same singularities as mode I crack problems:they have the r-1/2 singularities along the straight border of the crack, and at the corner of the crack, the singularities become weak when the corner of the crack is convex and strong when concave. Related Articles | Metrics | Comments（0）

Select

PLASTICITY OF PERFECT FULL CROSS SHEAR COLD ROLLING AND O. HOFFMAN'S FORMULA ZHIAO ZHENGCHEG, SONG MEIJUN, WANG MUQI Journal of Applied Sciences    1990, 8 (3): 223-231.   Abstract （573）      PDF（pc） （597KB）（108）       Knowledge map    Save New formulas for calculating the pressure per unit surface, mean pressure per unit surface and total compression load for perfect cross shear cold rolling are proposed: px=2K-qh+(qh-qH)(lnhx/h)/(lnH/h) px=2K-qH+(qh-qH)(lnhx/h)/(lnH/h) The new formulas, compared with O. Hoffman's formula, have higher accuracy. Based on these new formulas, a new theory of friction-free hill in crass shear cold rolling is proposed. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

Select

ESTIMATION OF NONLINEAR PARAMETERS OF HYDRAULIC SERVO SYSTEM BY USING KÄLMAN FILTER JIA LIANFENG, CHEN XUERUI, HU CHUNHUAI, KYOJIRO HAKOMORI Journal of Applied Sciences    1990, 8 (3): 232-240.   Abstract （463）      PDF（pc） （546KB）（191）       Knowledge map    Save For the high accuracy action of a hydraulic servo system, a linear dynamic model of the system including nonlinear elements is derived by using the Kälman filtering technique. Based upon the model derived, the flow gains to the displacement of the spool and to the load pressure of the servo valve, and the external torque are estimated. Related Articles | Metrics | Comments（0）

• page
• Page 1 of 2
• Total 65 records
• First page
• Prev page
• Next page
• Last page