A MODEL EXPERIMENT OF THE PLATE MOVEMENT

Detailed analysis of some difficult aspects has been made from modeling the platemovement. A new method of using differential density of material (instead of differentialtemperature) has been developed in the experiments. The effect of convection of mantleon the plate movement has been studied using a centrifugal technique, and a patternshowing the recurrence of the plate movement has been successfully obtained. In this paper, a criterion De=Dm is presented for the similarity of the model to thecounterpart of the original mantle. According to the criterion, what happens in the modelin a span of ten minutes suggests a process of the "original model" going on in geologi-cal time of three million years.     

X-RAY STUDIES ON THE STRUCTURE OF DES-PENTAPEPTIDE INSULIN AT 2.4 RESOLUTION——THE REFINEMENT OF THE STRUCTURE

The determination of an initial model for the crystal structure of des-pentapeptide in-sulin, using only the phase information obtained from the scattering of cadmium ions inthe native crystal, has been described. This paper describes the refinement of this modelagainst both the experimental X-ray observations and the a priori stereochemical observationsusing the method of restrained parameter least squares. The corrected and extended modelincluded not only all the non-hydrogen atoms of the protein and one cadmium ion, but alsosome 49 water molecules. Fourier syntheses using amplitudes of 2F_o-F_c, phase angles prob-abilistically combined from the anomalous scattering and model phase information, witheach term weighted according to its reliability gave clear results without detectable bias to-wards the current model. The final model has acceptable stereochemistry (root mean squaredeviation from ideal bond lengths 0.027 A), and predicts the observed X-ray scattering sat-isfactorily (R = 0.182 for all dat     

A MARKOV-TYPE ANALOG MODEL FOR PREDICTION OF TYPHOON MOTION IN NORTHWESTERN PACIFIC

In this paper, a Markov-type analog model for the prediction of the tropical cyclone motion is developed for the Northwestern Pacific. The probabilities are studied by using the United States National Hurricane Center HURRAN model as a guide. In order to approach and suit to the new circumstance continuously, a Markov process has been used to describe the probability forecast for typhoon movement. The model is different from the traditional analog method both in searching probability solutions and in renewing initial data.A transplantation model (Model 1) has also been developed by using the traditional analog methods. Both Model 1 and Markov-type analog model (Model 2) have been tested for 95 simultaneous cases, which are independent data for the years 1981 and 1982. It has been shown from this examination that the Markov-type model appears to give smaller forecast errors.     

REVERSE VARIABLE-ANGLE SYNCHRONOUS SPECTROFLUORIMETRY FOR RAPID SIMULTANEOUS DETERMINATION OF CHLOROPHYLL A AND CHLOROPHYLL B

Rapid simultaneous determination of chlorophyll a and chlorophyll b by reversevariable-angle synchronous spectrofluorimetry has been studied on a laboratory-constructedmicrocomputer-controlled versatile spectrofluorimeter.A method in estimation of scanparameters for the determination of two-component system by variable-angle synchronousspectrofluorimetry has been suggested     

SIMULTANEOUS DETERMINATION OF MULTICOMPONENT IN MIXED ACIDS BY MATHEMATICAL METHOD

A new method for the determination of components in mixed acids has beendeveloped.The mathematical model is obtained from samples of known composition and isthen used to predict the concentrations of components in unknown sample.The practicalutility of this method is demonstrated for simultaneous determination of two systems ofternary mixed acids and the results are satisfactory.     

INVERSION OF A NONLINEAR DYNAMICAL MODEL FROM THE OBSERVATION

A technique for inversion of a nonlinear dynamical model from the observations has been developed, and examined by using the Lorenz system. The results show that the Lorenz system can be accurately inversed by using the observation data set. This technique will be broadly used in establishing the nonlinear dynamical model from an actual data set.     

ANALYSIS OF PETROLEUM ACIDS IN DUSHANZI DISTILLATE

A method which involves conversion of carboxylic acids to corresponding hydrocarbons and determination of high-resoiution mass spectrometry has been applied to the analysis of petroleum acids in Dushanzi distillate and resulted in compound class identification of petroleum acids which have not been reported previously in Xinjiang petroleum.     

REFINEMENT OF THE STRUCTURE OF DESPENTAPEPTIDE (B26—30) INSULIN AT 1.5 RESOLUTION

The refinement of the structure of despentapeptide (B26-20) insulin (DPI) at 1.5 Aresolution is described in the present paper. Against the X-ray diffraction data of newlygrown crystals, the restrained parameter least-squares refinement of the structure alter-nated with model-rebuilding. The original 2.4A resolution model has been thoroughlyrefined and parts of it have been eonsiderably revised. The cadmium coordination struc-ture has been well determined, and appears to be a nearly ideal octahedron. After refine-ment 84 water oxygen atoms have been included in the final model; this gives us detailedinformation for studies on the water structure in the DPI crystal. The final crystal-lographic reliability index R value was 0.144 for 5678 unique observable reflexions (F_o great-er than 1.5σ (F_o)) in the 10-1.5A range; the refined model has a root-mean-squaredeviation from standard bond lengths of 0.04A.     

NUCLEATION BEHAVIOURS OF SILVER ON GLASSY CARBON MICROELECTRODES

The initial stage of silver deposition has been investigated using the microelectrodetechnique A disc shaped nucleus can be obtained on glassy carbon microelectrodes and the instanta.neous nucleation model applies for the process     

CHARACTERIZATION OF BLEND ACRYLIC FIBER''''S STRUCTURES

The fine structures, paracrystal, porous and phase structures of blend acrylic fibers have bencharacterized using techniques based on X-ray diffraction, gas adsorption, density, electron and opticalmicroscopy, mercury penetration method and IR spectroscopic analysis. The existence of a fibril-void structure, with voids and fibrils of the order of 10~2.to 10~3A diameter has been confirmed for thewet-spun blend fibers. It was found that the blend acrylic fiber in the present work is a kind of ma-trix-fibril fiber; phase separation takes place in it. Further studies about the effects of composition andsequence distribution of copolymers on structure of the blend fibers were made; and it was discoveredthat void volume in the blend fibers largely depends on the interface area between two polymer phases,and pore size and number on the particle size and number of the dispersing phase. An appropriatestructural model about the blend fibers has been described.     

STUDY OF STRONTIUM ISOTOPIC GEOCHEMICAL CHARACTERISTICS OF APATITE AND THEIR APPLICATIONS

An accurate determination has been made of the concentrations of rubidium and strontium of a number of apatites from different kinds of granitoid rocks in China on the mass spectrometer, and an intensive investigation has been carried out on the strontium isotopic geochemical characteristics of different kinds of apatite together with their applications in the study of petrogenesis, evolution of magma, division of rock belts, tectenic movements, isotopic geochronology, reconnaissance survey and ore prospecting, etc.     

MULTIPHOTON EXCITATION OF A WATER MOLECULE IN INTENSE LASER FIELDS

A stretch vibration Hamiltonian of H_2O has been derived by using the second quantization, unitary transformations and the optimization of coefficients. The energy spectrum obtained from this Hamiltonian is in good agreement with that of experiments. The multiphoton excitation and the energy absorption of H_2O in intense laser fields have been calculated.     

STUDIES ON DERIVATIVE FLUORIMETRY Ⅲ. DETERMINATION OF TRACE AMOUNT OF TERBIUM IN THE PRESENCE OF SODIUM DODECYL SULFONATE

The derivative fluorimetric characteristics of Tb—SDS and Tb—SDS—phenanthroline systems have been studied. The optimum conditions were obtained. The 2nd—derivative spectrofluorimetric method in the systems has been applied to the determination of trace amounts of terbium, in rare earth ore and their oxides. The results are satisfactory.     

SPECTROFLUORIMETRIC DETERMINATION OF GERMANIUM WITH MORIN IN WATER AND HEALTH DRINK

A highly sensitive and fairly selective spectrofluorimetric method has been developed for the determination of germanium with morin in tap water and health drink. The fluorescent reaction and optimal conditions of germanium with morin in phosphoric acid medium were studied. The detection limits of germanium in tap water and health drink were found to be 0.2 and 0.7μd/L respectively.     

Simultaneous Laser Thermal Lens Spectrometric Determination of Trace Platinum and Palladium in an Aquesous Solution

A selective and sensitive method for determination of platinum and palladium(Ⅱ）in an aqueous solution simultaneously by laser thermal lens spectrometry,based on the complex reaction of 2-(3,5-dichloropyridylazo)-5-dimethylaminoamiline(3,5-diCl-PADMA) with platinum and palladium,has been developed.It is shown that the palladium complex can be fromed at room temperature, while the platinum complex can be only formed after being heated in a boiling water bath.By using this difference of reaction temperature and the characteristic of the complexes mentioned above,the method for simultaneous determination of platinum and palladium was established in an aqueous solution without a pre-separation.The results show that the dynamic linear ranges of determination for platinum and palladium are 0.005-0.04μg/mL and 0.005-0.25μg/mL respectively,and that the detection limits are both 0.002/μg/mL.The method has been applied to the determination of platinum and palladium simultaneously in alloy and catalyst samples with satisfactory results.     

STRUCTURE DETERMINATION OF THE SILVER CARP INSULIN CRYSTAL

After rotation search of an orthorhombic crystal form of Silver Carp insulin, based on the known porcine 2-Zn insulin structure, the Silver Carp insulin molecules were positioned in the unit cell by applying the translation function and R-factor search methods. The packing of the molecules in the cell is reasonably good. A preliminary refinement of this model at 3.5 resolution has been carried out through the use of restrained least-squares method. The segments of polypeptide chain, which were not involved in the refinement, could be visible in the electron density map calculated using the refined atomic parameters.     

OBTAINING PRECISE CRITICAL DRAW RATIO OF DRAW RESONANCE IN MELT SPINING BY NUMERICAL SIMULATION OF DIFFERENCE EQUATIONS

Direct difference methods have been used to solve the simultaneous non-linear partial differential equations for melt spinning without recourse to linearisation or perturbation approximation. The stability of each difference schemes was studied by error analysis using the Taylor series, and by comparison of the results obtained from numerical simulation with the logical value in melt spinning. It is found that computation with 19 digit long double precision has significantly simplified the stability problem of difference equations. Using this method, the precise critical draw ratio of draw resonance in an isothermal and uniform tension spinning of Newtonian fluids can be obtained in between 20.218 and 21.219, a figure consistent with 20.218 which was obtained by a linear perturbation approximation method by Kase and Denn. It thus has paved the way to computation of full information for unsteady melt spinning processes using the difference method.     

KINETIC AND APPLICATION: STUDIES ON THE REACTION SYSTEM OF OSMIUM(Ⅳ)-ARSENIC(Ⅲ)-CHLORATE

The experiments have proved that Os(Ⅳ) has very strong catalytic effect on the chlorate oxidation of As(Ⅲ) in perchloric acid media, and As(Ⅲ) exhibits a sensitive single-sweep oscillopolarographic wave at-0.75 V vs. SCE. The kinetics of this catalytic reaction has been investigated by the initial rate procedure. The mechanism has been proposed. A new and highly sensitive catalytic reaction-oscillopolarographic method for the determination of ultratrace amounts of osmium has been described, based on the Os(Ⅳ) catalytic effect on the reaction. The linear range of 5.0×10~(-11)-4.4×10~(-9) mol/L and 6.0×10~(-9)-1.3×10~(-7) mol/L Os was obtained using the fixed-time procedure and the initial rate procedure, respectively. Osmium in refined ore was analysed by this method.     

Capillary electrophoresis-chemiluminecence detection of levodopa and benserazide in Medopar tablet

A novel method for the simultaneous determination of benserazide and levodopa using capillary electrophoresis(CE)- chemiluminescence(CL)has been developed.Under the optimal conditions,the detection limits(S/N=3)were 1.85μg/mL for benserazide and 0.12μg/mL for levodopa.This method was successfully applied to the determination of benserazide and levodopa in Medopar tablet,the results showed that the detected values are in accordance with those by official methods.