1989 Vol.7

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OPTIMAL PERFORMANCE OF THREE-HEAT-SOURCEHEAT PUMP YAN ZIJUN, CHEN JINCAN Journal of Applied Sciences    1989, 7 (1): 1-6.   Abstract （315）      PDF（pc） （404KB）（76）       Knowledge map    Save In this paper, we investigate a class of three-heat-source heat pumps, in which the only irreversible process is heat conduction. It is shown that the endoreversible three-heat-source heat pump is the most optimal one. Moreover,the relation between the optimal coefficient of performance and the rate of heating is induced. Thus the fundamental effect of thermal resistance on the optimal performance of a three-heat-source heat pump is expounded.The conclusions in this paper are more realistic than those in classical thermodynamics. Related Articles | Metrics | Comments（0） Cited: Baidu(8)

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ANALYSIS OF THE PROPAGATION CHARACTERISTICS FOR FINLINES WITH NARROW SLOTWIDTHS ANDTHICK FINS XU SHANJIA Journal of Applied Sciences    1989, 7 (1): 7-12.   Abstract （295）      PDF（pc） （426KB）（53）       Knowledge map    Save In this paper, we present an analytical method of the propagation characteristics for the finlines with extremely narrow slotwidths, the effect of fin thickness being taken into account also. The dispersion and impedance characteristics are calculated by the present method for the unilateral and bilateral finlines. The numerical analyses show that the method avoids the convergence problems mob with in computing the finlines with extremely narrow slotwidth by other numerical techniques, and justify that this method possesses the advantages of rapidity, effectiveness and simplicity. Related Articles | Metrics | Comments（0）

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EXPERIMENTAL MEASUREMENT OF ELECTRICALPROPERTIES OF A NEW POLAR CRYSTAL——TRIS(HYTROXYMETHYL) AMINOMETHANE (TAM) SHI ZIKANG, LI ZHENGDONG, SU GANBO Journal of Applied Sciences    1989, 7 (1): 13-18.   Abstract （397）      PDF（pc） （371KB）（57）       Knowledge map    Save We systematically investigated the electrical properties of the tris (hydroxymethyl) aminomethane crystal, a new type of pyroelectric crystal material. The properties studied are the dielectric constant, AC-and DC-resistivity, loss angle, and the phase transition character in the orientation of non-polar axes as well as transparence. The p/ε0 is about 10-10. It may be expected that it would be useful in the application to infrared pyroelectric detectors. Related Articles | Metrics | Comments（0）

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A RECURSIVE OPTIMAL (LSE) ALGORITHM OF DECONVOLUTION HUANG ZHONGPING, NI CHONGKUANG, XIE YUN Journal of Applied Sciences    1989, 7 (1): 19-24.   Abstract （341）      PDF（pc） （355KB）（93）       Knowledge map    Save Extracting the reflection coefficients of layers from seismic signals is important to the lithologic analysis and the success rate of drilling in finding the oil-gas-bearing structure. In this paper, an algorithm of deconvolution for the extraction of reflection coefficients is presented. The estimator got from this algorithm has the smallest variance of error among all linear estimators of reflection coefficients. The algorithm requires only a few computations and memory cells because of its recursive, in-place computation. Results of simulation indicate that, if the NSE (noise-to-signal ratio)is less than 30%, the algorithm is better in precision than Levinson's algorithm; if the NSR condition is worse, the two algorithms approximately have the same error curve. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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THEORETICAL AND EXPERIMENTAL INVESTIGATION ON SLOW WAVE TYPE MICROWAVE SENSOR YAN XIAOHONG, ZHANG ZHAOTANG Journal of Applied Sciences    1989, 7 (1): 25-29.   Abstract （365）      PDF（pc） （308KB）（67）       Knowledge map    Save The Karp type slow wave structure loaded with dielectric is described in theory, and a general dispersion equation is obtained.The effect of the dimensions of Karp structure and the effect of the permittivity of the loaded dielectric on dispersion characteristics are calculated by computer. The results thus obtained show the significance of Karp structure as a slow wave type moisture content sensor. As is proved by theory and experiment, this type of microwave sensor has special advantages and will come into use in the microwave measurement technique of nonelectric quantities. Related Articles | Metrics | Comments（0）

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INVERSE SCATTERING FOR STRATIFIED ANISOTROPICDIELECTRIC CHEN XIAOAN, ZHANG WENXUN Journal of Applied Sciences    1989, 7 (1): 30-34.   Abstract （285）      PDF（pc） （298KB）（56）       Knowledge map    Save The problem of inverse scattering for stratified anisotropic dielectric is investigated in this paper. The reconstruction of permittivity tensor for both stratified-homogeneous and stratified-inhomogeneous anisotropic lossless and lossy dielectric is studied. The method to determine the orientation of the principal dielectric axis and the principal permittivities is provided. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Hg 61P1 EXCITED STATE DENSITIES AND 185.0 nm SURFACE IRRADIANCES IN Ar-Hg DISCHARGE COLUMNS ZHU SHAOLONG, ZHENG LI, CAI ZUQUAK Journal of Applied Sciences    1989, 7 (1): 35-40.   Abstract （391）      PDF（pc） （409KB）（55）       Knowledge map    Save A spectral line absorption method was used to determine the Hg 61P1 excited state densities in low pressure mercury vapour discharge columns of various diameters. Two spectral lines, 576.96nm (transition between 63D2 and 61P1) and 579.07nm (transition between 61D2 and 61P1), were separately chosen for the measurements. The results obtained were in good agreement. From, the 61P1 state density data, we calculated the 185.0nm irradiance on the inner surface of various fluorescent lamps, using the resonance radiation imprisonment theory. It was concluded that the irradiance on the inner surface of the newly developed compact fluorescent lamps was one order larger than that of conventional fluorescent lamps, which seggested that highly stable phosphors to 185.0nm radiation or some method to re-duce the 185.0nm irradiance on phosphors was preferable in those new lamps. Related Articles | Metrics | Comments（0）

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MEASUREMENT OF INTERNAL STRESSES OF THREE DIMENSIONS IN RUBY SINGLE CRYSTALS LI LIQUAN, FAN DEPEI, QIU DIRONG Journal of Applied Sciences    1989, 7 (1): 41-46.   Abstract （314）      PDF（pc） （1230KB）（69）       Knowledge map    Save Internal strains in eight different directions in ruby single crystals are measured from the reflection pseudo-Kossel pattern. By solving the corresponding average strain and stress tensors, the internal stresses of three dimensions in the crystals can be calculated. Since internal stress is an important parameter for appraising the quality of rudy, the method mentioned above is recommendable. Related Articles | Metrics | Comments（0）

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TANTALUM BOAT USED AS SOURCE HEATER INVACUUM EVAPORATION OF PURE METALALLOYS AND SILICIDE FOR LSI ZHANG YIPING, XU YUANSEN Journal of Applied Sciences    1989, 7 (1): 47-51.   Abstract （327）      PDF（pc） （1020KB）（84）       Knowledge map    Save The pure tantalum boat used as a source heater for vacuum evaporation of pure Al, Cr, Si, Ti, Al-Si and TiSi2 films is developed. This resistor heater method is attractive because it is simple and inexpensive, there is no ionization radiation and no mobile ion contamination from the heater, and the composition and properties can be controlled. Now this method is incorporated in our LSI development. Related Articles | Metrics | Comments（0）

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THE ELECTRICAL CHARACTERISTICS OF GaAs-SiO INTERFACE FABRICATED RY LOW TEMPERATURE PROCESS SHENG CHI, REN YUNZHU Journal of Applied Sciences    1989, 7 (1): 52-56.   Abstract （319）      PDF（pc） （376KB）（60）       Knowledge map    Save A low-temperature process for producing the GaAs MIS structure based on the slow evaporation of powder SiO on the room-temperature GaAs substrate is developed. The as-grown GaAs-SiO MIS has a low interface state density of 8×1011/cm2·eV and a low hysteresis. No frequency dispersion of the accumulation capacitance is found, as explained by the frequency-dependent permittivity of SiO. Related Articles | Metrics | Comments（0）

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ENHANCED ANNEALING EFFECT OF DOUBLE ION IMPLANTED Si-SUBSTRATE ZHU JINLIANG, CHENG DONGFANG, WANG LIANG, CAI RENKANG Journal of Applied Sciences    1989, 7 (1): 57-60.   Abstract （321）      PDF（pc） （941KB）（130）       Knowledge map    Save The enhanced annealing effect resulting from argon and boron implantation in silicon is described. The small sheet resistance value is obtained by the four-probe measurement at about 500℃. It is observed by SEM and Raman spectroscopy that the radiation damages of crystalline lattices are well recovered. Related Articles | Metrics | Comments（0）

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THE MEASUREMENT OF SPECIFIC CONTACTRESISTANCE OF M-S BY PROBE HEADSOF THE IN-LINE FOUR PROBES CHEN CUNLI, HUA WENYU Journal of Applied Sciences    1989, 7 (1): 61-64.   Abstract （437）      PDF（pc） （239KB）（124）       Knowledge map    Save In this paper, a simple method to measure the specific contact resistance of metal-semiconductor ohmic contact is developed, using the probe heads of the inline four probes. The equations to measure the specific contact resistance for a thin semiconductor layer have been derived. The experimental results are in good agreement with the in-line geometry transmission line model. Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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PbO2/MnO2 SEMICONDUCTING THIN FILM TECHNOLOGY AND ITS ESCA/AES STUDY YU ZHIZHONG, HU NANSHAN, CAI BINGCHU Journal of Applied Sciences    1989, 7 (1): 65-70.   Abstract （393）      PDF（pc） （452KB）（56）       Knowledge map    Save The PbO2/MnO2 semiconducting thin film is deposited by RF bias sputtering, doping PbO2 with MnO2. This film, on account of its good properties at high and low temperatures, can be used to fabricate large capacity film capacitor TLMM. The MnO2 thin film, which can be employed to manufacture the multiplier phototube, is sputter-deposited directly from powder MnO2, its composition and chemical aspect approaching standard MnO2. ESCA and AES techniques are used to monitor the ratio of PbO2/MnO2 and the composition of manganese oxide of the semiconducting thin film. In this way, the sputtering parameters are determined. Related Articles | Metrics | Comments（0）

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STUDY AND DESIGN OF CMOS SMOKE DETECTOR CIRCUIT CHEN SHILING Journal of Applied Sciences    1989, 7 (1): 71-74.   Abstract （345）      PDF（pc） （257KB）（52）       Knowledge map    Save This paper presents the principles and main units design of the CMOS smoke detector IC, which we have researched on and fabricated. The IC main features are:the detector input impedance is high, the internally set detector threshold can be regulated via the external resistor, the output guard on each side of the detector input can prevent false triggering, and a piezoelectric horn and a LED driver are provided. Related Articles | Metrics | Comments（0）

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THE STUDY OF Fe3O4 COATED WITH SINGLE LAYER MOLECULAR OLEIC ACID ZENG HUANXING, ZHOU WENYUN Journal of Applied Sciences    1989, 7 (1): 75-80.   Abstract （389）      PDF（pc） （1157KB）（77）       Knowledge map    Save In this paper, the ultra-fine particles of Fe3O4 coated with a single layer of molecular oleic acid were prepared by the neutralizing co-precipitation solution-adsorption process. The particle size, shape and structure of Fe3O4·nOA wore primarily studied by electron microscopy, infrared spectroscopy, DTA-TG, X-ray diffraction, etc. Some of the methods of calculation and measurement of the particle size and quantity of oleic acid in Fe3O4·nOA were provided by testing and supposition. Related Articles | Metrics | Comments（0）

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A STUDY ON APPEARANCE POTENTIAL SPECTROSCOPY IN EVAPORABLE GETTERS SHAO LIWEI, LIU JIEME, LOU WEIHONG, CHEN DESEN, HU SIAN Journal of Applied Sciences    1989, 7 (1): 81-85.   Abstract （377）      PDF（pc） （323KB）（55）       Knowledge map    Save Using AEAPS and EPAPS-AEAPS compound analysis technique, the analysis of surface component for the evaporable getter is introduced. The surface states of different qualities of evaporable getters are compared and impurities in getters are studied, introducing a principal construction and a detective graphic. It is very useful in applying the appearance potential spectroscopy to getter production. Related Articles | Metrics | Comments（0）

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EFFECT OF COPOLYMER OF VINYL CHLORIDE-VINYLACETATE-VINYL ALCOHOL ON ADHESION OFINTERFACES IN MAGNETIC COATING WANG PING, HUANG YULI, QIU ZHAOYAO, NIU AIJIE, LI ZONG Journal of Applied Sciences    1989, 7 (1): 86-90.   Abstract （332）      PDF（pc） （1098KB）（66）       Knowledge map    Save The effect of two kinds of copolymer of vinyl chloride-vinyl acetate-vinyl alcohol, which are different in molecular weight, on the dispersibility of γ-Fe2O3 particles in butanone and on the adhesive tension between γ-Fe2O3 and the copolymer and on the peel strength between the copolymer and the polyester film are studied. The above-mentioned properties are improved when the molecular weight of the copolymer is 3.4×104 as proved by both experiment and theory. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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A MODEL OF STRAIN CENTERS AND STRAIN COMPENSATION FOR DEVICE PASSIVATION LI DANZHI Journal of Applied Sciences    1989, 7 (1): 91-94.   Abstract （363）      PDF（pc） （1119KB）（58）       Knowledge map    Save Based on the infrared strain distribution photo taken and the shape of spots on the Si wafer after thermal oxidation, this paper presents a model of strain conters. The model brings to light the minority carrier life dependence on strain centers and explains the improvement of transistor current gain due to the strain compensation of the double layer dielectric films. Related Articles | Metrics | Comments（0）

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THE SATURATION PHENOMENA AND FOLDOVER EFFECTS OF THE FERROMAGNETIC RESONANCE IN YIG SINGLE CRYSTAL FILMS AT HIGH POWERLEVELS ZHANG YOUTING Journal of Applied Sciences    1989, 7 (2): 95-100.   Abstract （437）      PDF（pc） （478KB）（91）       Knowledge map    Save This paper further investigated the characters of the pulsed microwave power ferromagnetic resonance (FMR) absorption in YIG single crystal films under per-pendicular pumping. The single crystal YIG film samples (5.1μm thick and 500μm in diameter) were prepared by the liquid phase epitaxy on gadolinium gallium garnet substrates and photolithographic etching procedures. The pulsed microwave power FMR absorption curves were measured for three different configuration pum-pings at a frequency of 9.18GHz under room temperature. The experimental results show that the main character of the FMR profiles under pulsed microwave powers with low duty cycles is a linewidth broadening effect due to the spin-wave instability processes, and the up-sweep and down-sweep FMR profiles are basically identical. However, the foldover effects of the FMR profiles occur at the high power levels. Related Articles | Metrics | Comments（0）

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THE CALCULATION OF STEADY TEMPERATURE FIELD AND ENERGY DISSIPATION OF ROLLING TIRE C. OUYANG, XH ZHENGYI Journal of Applied Sciences    1989, 7 (2): 101-107.   Abstract （316）      PDF（pc） （429KB）（60）       Knowledge map    Save Using the thermal method, the inner temperature field and energy dissipation of a thermal-steady weighted rolling tire are calculated with a FORTRAN program, the outer boundary temperature and thermal constant of the material being treated as known values. The calculated result is in agreement with that of the experiment. Related Articles | Metrics | Comments（0）

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INVESTIGATION OF INDUCTIVE SEPTA WINDOW DISCONTINUITIES RONG AOSHENG, LI SIFAN Journal of Applied Sciences    1989, 7 (2): 108-114.   Abstract （292）      PDF（pc） （403KB）（88）       Knowledge map    Save This paper presents a new type of waveguide discontinuities-inductive septa windows deposited on a dielectric substrate. A formulation for the equivalent circuit parameters of the discontinuities with superior convergency is derived by the transverse resonance method with the singular integral equation technique. As an example, an inductive bilateral septa window is computed. When the configuration is degenerated into an inductive all metal window with zero thickness, the numerical results are in good agreement with the available data in Literature[1]. Related Articles | Metrics | Comments（0）

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ON THE CHARACTERISTICS OF DIELECTRIC COVERED WAVEGUIDE SLOTS XIA KEJIN, YANG QIJI Journal of Applied Sciences    1989, 7 (2): 115-123.   Abstract （476）      PDF（pc） （530KB）（80）       Knowledge map    Save A mixed domain theory is developed to analyze the characteristics of the dielectric covered longitudinal waveguide slots. Using the methods of asymptotic term and singularity separations and the method of differentiation shifting, the quantity of computation is greatly reduced. The comparison of the computed results with the experimental results is given, and the reason for the non-resonance phenomenon of the large deviated slot on the flat waveguide is shown. Related Articles | Metrics | Comments（0） Cited: Baidu(4)

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THE PHASE TRANSITION AND ELECTRICAL PROPERTIES OF In-Sb ALLOY FILMS WANY HAO, GAN FUXI Journal of Applied Sciences    1989, 7 (2): 124-128.   Abstract （319）      PDF（pc） （1256KB）（63）       Knowledge map    Save We investigated the dynamic processes of the phase transition of InxSb1-x (x=0.27~0.46) alloy films. The changes of the electrical properties due to the phase transition were studied. The relationships between the electrical properties of In-Sb films and their structures were discussed. Related Articles | Metrics | Comments（0） Cited: Baidu(18)

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SOME STUDIES ON THE MODELING AND SIMULATION OF OPTICAL LITHOGRAPHY FOR VLSI FENG XIANGMING, RUAN GANG Journal of Applied Sciences    1989, 7 (2): 129-136.   Abstract （377）      PDF（pc） （1217KB）（92）       Knowledge map    Save In this article, some physical models related to the optical lithography simulation are discussed. A program, FUPLIS, which is used to simulate the VLSI lithography process has been developed. Some simulated results given by FUPLIS are presented. And it is shown that the simulated results play an important role in the understanding and guidance of the lithography process. Related Articles | Metrics | Comments（0）

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THE SIMULATION OF HOT CARRIER EFFECT IN SMALL GEOMETRY MOSFET WEI TONGLI, HO YIE Journal of Applied Sciences    1989, 7 (2): 137-142.   Abstract （493）      PDF（pc） （381KB）（85）       Knowledge map    Save For practical use, a simulation method of hot carrier effect in the small geometry MOSFET is proposed by the direct solution of the Poisson equation and a corresponding software is developed in this paper. The result of the simulation is close to that calculated using an accurate two dimensional MOST analysis program and is in reasonable agreement with the experimental data. Also, the CPU time is one to two orders lower than that of the 2-D simulation. Related Articles | Metrics | Comments（0）

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THE EXPRESSIONS OF TRANSMISIVITY IN THE METHODOF LIGHT CUT-OFF AND THE RELATION BETWEEN COMPOSITION OF Hg1-x Cdx Te AND TRANSMISIVITY DAI XIANXI, WANG XINDE Journal of Applied Sciences    1989, 7 (2): 143-147.   Abstract （393）      PDF（pc） （307KB）（62）       Knowledge map    Save The expressions of transmisivity in the method of light cut-off (for short and long wave-length oases respectively) were dirived: f(νc)=1+15/(π4){xc3ln(1-e-xc)-3∑n=0∞ e-(n+1)xc[2/((n+1)4)+(2xc)/((n+1)3)+(xc2)/((n+1)2)]} (xc=(hνc)/kT ≥ 2) f(νc)=15/(π4)xc3[1/(3)-(xc)/8+(xc2)/60-0.0001984xc4+0.0000037xc6-7.5156325×10-8xc8+1.6059044×10-9xc10-……] (xc ≤ 2) These expressions were used in the experimental measurements. It was proved that the expressions were useful in improving the accuracy and measuring speed. According to these expressions a table (with 3000 data and an accuracy of 10-5) and a useful expression (with a calculating accuracy of 2×10-4) of x (the composition of Hg1-xCdxTe versus F (transmisivity) were obtained: x=0.1334+0.8240F-2.140F2+4.840F3 -5.450F4+2.550F5 (0.17 < x < 0.443) Related Articles | Metrics | Comments（0）

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A CONTROL SYSTEM BASED AN MICROCOMPUTER FOR MOCVD ZHAI QIGANG, XU LINMUU, CHEN WEIMIN, YU GUANGYI Journal of Applied Sciences    1989, 7 (2): 148-152.   Abstract （428）      PDF（pc） （356KB）（73）       Knowledge map    Save This paper describes a control system for MOCVD by the use of a microcomputer. The MOCVD is a metal-organic chemical vapor deposition (MOCVD) system specifically designed for developing epitaxial layers of gallium-arsenide and other Ⅲ-Ⅴ/Ⅱ-Ⅵ semiconductor compound materials. It is also useful for the investigation of super-lattice. The control system consists of a microcomputer interface, a mass flow control for each gas, a temperature control for the baths for each metal-organic source, a temperature control for RF-heated susceptor, a gas switching manifold, a gas panel and so on. The accuracy of the temperature control for the RF-heated susceptor is 0.05%, The error of the temperature control for metal-organic baths is about-15±0.01℃. The fully automated process control is achieved in a safe, accurate manner by the use of the control system based on a microcomputer under any adverse circumstance. Related Articles | Metrics | Comments（0）

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THE HYPERPLANE RECOGNITION MODEL FOR THE PROCESSES OF RESTRICTED RESPONSE——THE APPLICATION OP HANDLING THEEESULTS OF EXPEKIMENTAL PLAN XU CAN, ZHANG WEIMING, CHEN NIANYI, LIAN YOUSHEN, HE SHEQIAN Journal of Applied Sciences    1989, 7 (2): 159-164.   Abstract （332）      PDF（pc） （393KB）（61）       Knowledge map    Save This paper, based on the pattern recognition point of view, deals with the problems of restricted response within the narrow upper and lower control criteria by combining the eigenvalue decomposition method with the experimental design technique. The plane distributive structure in the experimental design space is determined by decomposing the covariance matrix of the specified pattern class. This method is used to analyze the relationship between the alloy composition and the alloy expansion coefficient. A quasilinear hyperplane is obtained in this design space. The stable design level is shown by the two-dimension display. Related Articles | Metrics | Comments（0）

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MEASURING SEA ICE THICKNESS WITH 10-CM MICROWAVE RADIOMETER JIN HUIQIN, YANG GUANGLIN, CHEN DINGREN Journal of Applied Sciences    1989, 7 (2): 165-168.   Abstract （448）      PDF（pc） （269KB）（100）       Knowledge map    Save This paper describes the performance of the 10-cm microwave radiometer developed in our laboratory, as well as the principle and the method for the measurement of ice thickness. This equipment was used to conduct experiments during the flight test in Liaodong Bay in 1986.The characteristics of the brightness temperature changes with the ice thickness and the distribution of the ice types on the flight-path have been obtained. The results of the test show that the radiometer is very effective for the measurement of ice thickness. Related Articles | Metrics | Comments（0）

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THE INFLUENCE FACTORS AND PROPERTIES OF THE RADIATION SYNTHESIS HYDROGEL MATERIAL YANG YUEQI, LIU YUMING Journal of Applied Sciences    1989, 7 (2): 169-173.   Abstract （379）      PDF（pc） （364KB）（93）       Knowledge map    Save This paper reports the results of the study on the influence factors and properties of the electron beam synthesis hydrogel material. 1 High quality hydrogel matericl can be obtained by the electron beam of high doge rate at the normal temperature. 2. In the range of l-10×l0Gy/s and l~2×l0Gy, the dose rate and the dose have no evident influence on the properties of soft contact lens. 3. When a moderate amount of water is added to the compounding, the elongation can be increased. 4. When the compounding includes the water-hating monomer such as butyl acrylate, the tensile strength of soft lens is increased and the water absorption is decreased. 5. The hydrogel material accords completely with the demands of biology. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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COMPLEX RAY PARAXIAL APPROXIMATION:PRINCIPLE AND APPLICATIONS RUAN YINGZHENG, LEOPOLD B. FELSEN Journal of Applied Sciences    1989, 7 (2): 174-178.   Abstract （377）      PDF（pc） （307KB）（79）       Knowledge map    Save Complex ray tracing provides an efficient approach to dealing with the propagation and scattering of HF Gaussian-like beams, but the search for the ray path from source to observer is the most time-consuming part in the numerical implementation of the complex ray scheme. Based on the complex ray theory and the perturbation principle, an approximation method for the evaluation of beam fields in the paraxial region is developed, which simplifies the computation substantially, The theory and procedure of the method are presented and some application examples and numerical results are given. Related Articles | Metrics | Comments（0） Cited: Baidu(23)

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INTRINSIC GETTERING EFFECTIVENESS IN HEAVILY ARSENIC-DOPED SILICON TAN SONGSHENG, ZHU DEGUANG, WANG ZIYUN Journal of Applied Sciences    1989, 7 (2): 179-181.   Abstract （362）      PDF（pc） （1036KB）（62）       Knowledge map    Save The intrinsic gettering effectiveness in heavily arsenic-doped silicon has been investigated. It has been shown that the quality of epitaxial layers is improved by the intrinsic gettering process. The generation lifetime has increased by more than 15 times, and the diode reverse leakage current has been improved by two to three orders of magnitude. Furthermore,the results indicate that the intrinsic gettering effect can perform in a longer distance than the extrinsic gettering effect by heavy boron diffusion. Related Articles | Metrics | Comments（0）

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AN ACCURATE SEMICONDUCTORIC TEMPERATURE TRANSDUCER FANG PEISHENG Journal of Applied Sciences    1989, 7 (2): 182-184.   Abstract （283）      PDF（pc） （213KB）（56）       Knowledge map    Save A new semiconductor IC temperature transducer is described. This transducer has the difference Vbe in the pair transistor base-emitter voltages, which is proportional to the absolute temperature. The test results show:the device has high accuracy of ±0.5℃ from -50℃ to 150℃, easy calibration ann low power dissipation. Related Articles | Metrics | Comments（0）

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MICROWAVE CHARACTERISTICS OF A FERROFLUID XU PEIYING, LU HUAIXIAN, DU YOUWEI, WANG TINGXIANG Journal of Applied Sciences    1989, 7 (2): 185-188.   Abstract （416）      PDF（pc） （240KB）（59）       Knowledge map    Save The microwave tranamission characteristics of a ferrofluid (the carrier liquid being hydrocarbon and the magnetic particles being magnetite) magnetized with the biasing field H, have been measured. The phenomenon of ferro-magnetic resonance absorption in the ferrofluid has been observed. When the ferrofluid is biased far from the resonance field, low-loss transmission and non-reciprocal transmission, i.e., non-reciprocal attenuation and shift in the waveguide have been obtained respectively. Related Articles | Metrics | Comments（0）

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AN ELECTROSTATIC FIELD OF FOCUSING AND DEFLECTION IN THE SAME SPACE WANG YANG, JIANG XIANGQI, HUA ZHONGYI Journal of Applied Sciences    1989, 7 (3): 189-193.   Abstract （342）      PDF（pc） （1151KB）（54）       Knowledge map    Save Until recently no electrode system can generate both electrostatic focusing field and deflecting field in the same space without any interference. Yet this can be done if some proper continuously varying potentials that satisfy two individual field requirements are applied on the boundaries of a closed structure. For instance, a new electrostatic quadrupole of square cross-section can be used as a focusing lens and for x-y deflection simultaneously. Preliminary results of the electron-optical experiment show that the proposed structure is correct. Related Articles | Metrics | Comments（0）

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THEORETICAL ANALYSIS AND CALCULATION OF BACKLASH FOR CENTER-ADJUSTABLE GEAR PAIR ZHANG RONGXIN, GONG ZHENBANG Journal of Applied Sciences    1989, 7 (3): 194-200.   Abstract （433）      PDF（pc） （441KB）（54）       Knowledge map    Save This paper introduced the mathematical model concerning gear ratios, strictly analyses the statistical characters of backlashes based on the stochastic process, theory, and then deduced the backlash calculation formulae for engineering designs and the parameters concerned:the coefficient of mean value, the coefficient of standard deviation, the coefficient of statistical value taken, and so on. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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SIMULTANEOUS DETERMINATION OF SUBSTRATEOPTICAL CONSTANTS AND FILM PARAMETERSBY MULTIPLE ANGLE OF INCIDENCEEL LIPSOMETRY ZHOU QINGCHU, XU NAIXIN, SHIH SHENGTAI Journal of Applied Sciences    1989, 7 (3): 201-206.   Abstract （367）      PDF（pc） （464KB）（92）       Knowledge map    Save The dependence of the uniqueness in simultaneous determination of substrate optical parameters and film parameters by multiple angle of incidence ellipsometry on the correlation among these unknown parameters was discussed. A general guide to the selection of angle of incidence was proposed. The first derivatives of △ and ψ with respect to ns, ks, nf, kf, d and angle of incidence φ0 were computed for Si-SiO2 and stainless steel-passive film systems. The correlation among the unknown parameters was examined. A random simplex method was developed to obtain results for these two systems. Related Articles | Metrics | Comments（0）

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THE ACCURATE SOLVING PROCESS OF LINEAREQUATIONS AND ITS APPLICATION IN EXTREMUM OF FUNCTIONAL ZHANG KECUN Journal of Applied Sciences    1989, 7 (3): 207-212.   Abstract （311）      PDF（pc） （384KB）（81）       Knowledge map    Save In the process of engineering optimum, a group of special linear equations of order n have been obtained from the abstract mathematical model and the analytic expressions for the solutions have also been. derived. By means of the analytic expressions for the solutions, a new approach for solutions has been provided to a type of conditional extremum of functional. Noticeable achievements have been made with the application of this approach in optimum engineering designs. Related Articles | Metrics | Comments（0）

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SOLUTION OF THREE DIMENSIONAL ELECTROSTATIC PROBLEM BY BOUNDARY ELEMENT METHOD WU WANCHUN, WEN GEYI, LIU XUEGUAN Journal of Applied Sciences    1989, 7 (3): 213-218.   Abstract （433）      PDF（pc） （343KB）（96）       Knowledge map    Save A detail discussion for the solution of the three dimensional electrostatic problem by using the boundary element method is presented in this paper. The boundary element solutions for the capacitance of several isolated conductors are given. Results show that the method is quite effective, as it is precise and requires less computation time. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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A NEW METHOD FOR CALCULATING THE NOISE PARAMETERS OF MESFET CAI CHUNQING, CAI SHUZHEN, RUAN GANG, WANG JIANWEI Journal of Applied Sciences    1989, 7 (3): 219-224.   Abstract （339）      PDF（pc） （419KB）（54）       Knowledge map    Save In this paper a new method for calculating the noise parameters of MESFET is presented. Using this method, noise parameters can be calculated not only from structure parameters or S parameters of MESFET separately, but also from the structurc parameters and S parameters simultaneously. This method possesses higher precision than those methods in common use. In this method noise parameters are calculated by using the rigorous network theory and lead inductances are included in the equivalent circuit of MESFET, so this method can be used up to a higher frequency range than Fukui's. Program MESNOC realizes these ideas. It is very useful for research and development of new device as only the nodes of the equivalent circuit and the values of the elements are required when unning MESNOC. The values of minimum noise figure calculated by using MESNOC agree with the values measured. Related Articles | Metrics | Comments（0）

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