THE SIMULATION AND OPTIMIZATION OF GRADIENT ELUTION HPLC

The movement of a particular component along an HPLC column is studied on the ba-sis of equilibrium equations. Numerical simulation of multi--step gradient elution HPLC isperformed by means o? a personal computer program. The location x, as a fraction of thecolumn length, for a given time t o? each compound is calculated, the velocity and corre-sponding acceleration are given as well. Diagrams for x,dx/dt and d~2x/dt~2 versus t display themovement process of the different components along the HPLC column during gradient elu-tion. The prediction of the retention time and peak width, and the optimization for the multi-step gradient elution HPLC are all based on such simulation and the molecular structure ofthe. components is separated as well.     

STUDIES ON THE SEQUENCE STRUCTURE OF TPA/EG/PHB LIQUID CRYSTALLINE COPOLYESTERS

In this paper, the sequence structure of TPA/EG/PHB liquid crystalline copolyesters made from different synthetic methods has been studied by ~1H-NMR with the help of computer program of processing peaks. The results showed that the ether bonds were not observed in TPA./EG/PHB copolyesters and the synthetic process had a great effect on their sequence structure. Under certain conditions, the high,random TPA/EG/PHB copolyesters which were considered to have higher performances than PET/xPHB could be obtained.     

AN INDIRECT METHOD FOR DETERMINATION OF PARAMETERS IN THE FORECAST MODEL

An indirect method for determining some parameters in a forecast model has been developed, by which the program of the original model with little modification can be used as a subroutine of the inversion system and the optimum estimate of the parameters can be obtained by calling the subroutine time after time. It is specially useful for the sophisticated numerical weather prediction model. It may also be utilized to improve the forecast timely in case of obvious differences between the recent observations and the forecasts. The effect of the method is verified by numerical simulation tests with simple models.     

THE RADIATION CROSSLINKING OF EPR/SBR BLEND

The radiation crosslinking of EPR/SBR blend has been studied. A relationship between sol fraction and radiation dose for the different weight ratio polymer blends and the method to calculate βb value of EPR/SBR blend system have been established.     

THE FITTING CURVE METHOD OF WHOLE GC CHROMATOGRAM AND ITS APPLICATIONS

In this paper, the principle and mathematical model of an intelligent gas chromatographic program, Chgr A-84 for GC chromatogram curve fitting have been presented. The exponentially modified Gaussian (EMG) model can be used to describe the profile of a GC tailing peak by means of computer program. By the systematic investigation and preliminary theoretical explanation of its parameters τ and σ of various solutes, an approximately linear relationship between τ or σ and retention time t_r has been found. The program ChgrA-84 can be used for getting the imitating GC chromatogram at different temperatures and making area measurement of overlapping peaks with curve fitting method.     

FURTHER STUDY ON THE INHERITANCE OF THE GENIC MALE-STERILE WHEAT OF TAIGU AND THE PRODUCTION OF THE DOMINANT MALE-STERILE OCTOPLOID TRITICALE

According to the result of the studies of the Taigu genie male-sterile wheat of the predecessor, a series of inductive inference was made at first. We used the Taigu genic malesterile wheat to make cross with rye to produce polyhaploid plant. By chromosome doubling, the dominant male-sterile gene became homozygous under artificial condition. The result of the experiment obtained shows that the expression and segregation ratio of the stamens of the haploid, amphiploid and the hybrid progenies of amphiploid plants well correspond to the inductive inference, so it confirms once again that a single dominant gene determines the male-sterility of the Taigu genic male-sterile wheat.The authors verify that the Tal gene not only can be expressed normally in common wheat's genetic background, but also can be introduced into the octoploid triticale. The first dominant genic male-sterile octoploid triticale is produced and has been used in triticale breeding program.     

THE RELATION OF SEQUENCE DISTRIBUTIONS OF S-SBR TO ITS MOLECULAR WEIGHT DISTRIBUTIONS

The relationship between sequence distributions and molecular weight distributions of S-SBR, obtained from styrene and butadiene anionic copolymerization at various conversions with THF/Li~+ as an initiator has been studied by ~(13)C-NMR,GPC. The results showed that the molecular weight distributions of the copolymer couldbe correlated sophisticatedly to the binary sequcne distributions or the monomer unit distributions of the copolymer in a corrected Poisson's distribution from.     

DETERMINATION OF THE COMPLETE NUCLEOTIDE SEQUENCE OF HBV adr NC-1 DNA

On the basis of sequencing the large DNA-fragments which have been inserted intoM_(13)mp_8, we design a simple strategy to determine the complete nucleotide sequence of HBVadr NC-1 DNA with chain termination method. The whole genome is 3195 nucleotides long.Five reading frames are observed. The gene location and organization are shown.     

THE CRYSTAL STRUCTURE OF THE ADDITION COMPOUND OF DECAVANADIC ACID AND 5,7-DIMETHYL-2, 3-DIHYDRO-1, 4-DIAZEPINIUM

The title compound crystallizes in the space group C_(2h)~5-P2_1/n with unit cell constantsa=10.938 A, b=19.189 A, c=13.384 A and β=105.09°. Intensities of 4022 independent reflec-tions were collected with four-circle diffractometer using MoKa radiation. After reduction fordiffractometer data, we derived first the position parameters of all the V atoms by directmethod using SHELXTL program. The coordinates of all the non-hydrogen and hydrogenatoms were obtained from successive Fourier and difference sytheses. The block-diagonalleast-squares refinement for all atoms gave a final discrepancy weighted factor R_w=0.050. The result of structure analysis shows that four protons of each decavanadic acid arecaptured by the nitrogen atoms involved in the azepine molecules which are condensation pro-ducts of ethylenediamine with acetylaceton. In crystal, the isopoly-decavanadate anion, 7-member heterocyclic azepium and the crystal water are linked together by ionic forces andhydrogen bonding and the chemical content within a unit cell has been identified as 2[H_2V_(10)O_(28)]~(-4)·8[C_7N_2H_(13)]~( 1)·12H_2O.     

SIMULATION OF THE SEISMIC TECTONIC STRESS FIELD IN NORTH CHINA

The paper reviews several methods of simulation used in this country to recover currenttectonic stress field related to earthquake occurrence in North China. The aim is to evaluatethe degree of seismic risk around Beijing area. The methods used are computational ormathematical simulation by the finite element method and experimental or physical simulationby the photoelastic method and the grid method. The results obtained by these methods arebriefly described. Most simulations indicate that Beijing is not a region of seismic risk.     

A MATHEMATICAL SIMULATION OF EARTHQUAKE SEQUENCE IN NORTH CHINA IN THE LAST 700 YEARS

A scheme in Fig. l is used to simulate the earthquake sequence in North China in the last 700 years. With a postulated fault system, a mechanical parameter distribution and suitable boundary tractions, the stress field is computed by finite element method in plane strain. The fault zones are treated as elastic-perfectly plastic medium which flows according to Coulomb's criterion and its associated flow rule. An earthquake is simulated by lowering the static coefficient of friction to a kinetic one at the epicenter to cause a slip there and arrived at a new equilibrium position. The differences in displacement, stress, etc. before and after the lowering are considered to be due to the earthquake and compared to observations. After adjustments of parameters and boundary tractions, the results are satisfactorily compared with the major earthquake sequence of 14 events M_s≥7 and regions of seismic risk in the last 700 years. Possible localities of future earthquake risk after the Tangshan earthquake and ef     

THE CRYSTALLOGRAPHIC STRUCTURE OF THE PHOTOOXIDIZED PRODUCT OF HYPOCRELLIN A AND THE STUDY OF THE PHOTODYNAMIC ACTION MECHANISM

In attempting to study the phototherapeutic action and the photosensitized oxygenation mechanism, we have determined the crystal structure of the main oxidized product of hypocrellin A (HA). It was crystallized in monoclinic system with space group P2_1. The cell data are: a=10.030(3), b=8.877(3), c=15.764(5), β=104.50(2)°, Z=2. The crystal structure has been determined by direct method and refined to a final R of 0.055 based on the 1408 observed reflections with l>2.5σ(Ⅰ). The photooxidized product is composed of a heptacyclic aliphatic hydrocarbon connecting with two α-naphthoquinone derivatives as its skeletal molecule. No peroxidic linkage has been found. On the basis of the crystal structure determined, we have deduced part of the process of formation of the oxide, ⅰ. e. firstly, the peroxide was formed by photocycloaddition of oxygen molecule to Hypocrellin A, then thermodissociation took place to form a stable oxide.     

STUDIES ON THE CRYSTAL STRUCTURE OF Al-(D-TRYPTOPHAN) INSULIN

We have determined the crystal structure of Al-(D-Trp) insulin and discovered that it belongs to the trigonal system with space group R3. The parameters of the unit cell are a=b=78.6, c=50.0. A set of data for half a sphere reciprocal space to a spacing of 2.2 were collected. The model was adjusted and refined by using a step-by-step approach and a stereochemically-restrained least squares program, assisted by manual revision based on the difference Fourier maps, to a final R-factor of 0.218. The main and side chains of both Al-D-Trp residues in the asymmetric unit are well ordered. The packing of Al-(D-Trp) insulin in the unit cell, the conformational differences with other insulin structures and its structure and function relationship bave also been discussed.     

THE NUCLEOTIDE SEQUENCE OF SURFACE ANTIGEN GENE OF HEPATITIS B VIRUS SUBTYPE adr

The nucleotide sequence of the XhoI-BamHI fragment (1279bp), which contains the sur-face antigen gene (S gene) of HBVadr, was determined by Maxam and Gilbert's method.By comparing the differences both of the nuclectide sequence in the S gene and its codedamino acid sequence between adr and those reported for adw, ayw and adyw, some new var-iation sites were discovered. The differences were mainly distributed in the two hydrophilieregions. However, at those sites which might show biological function, there were no varia-tions among different subtypes, they are relatively conservative in heredity and evolution.Comparing the variation of the nucleotide sequence in the S gene region with that in thenon-S gene region, it is shown that the frequency of variation in the non-S gene regiondoubled that in the S gene region. Tim S gene region is more conservative.     

STRATIGRAPHIC AND GEOCHRONOLOGIC ANALYSES OF THE QUATERNARY DEPOSITS IN THE THREE-LAKE REGION OF QAIDAM BASIN

The Qaidam Basin is a larger sedimentary basin in western China where the thickness of the Quaternary deposits is in the range of 2000-3000 m at its subsiding center. This paper first dates palaeomagnetically the cores obtained from the five continuously sampled intervals and those from a typical profile, determineds the age of the index fossil zones, and calculates the deposition rates for the varve deposits based on the sedimentological analysis. As a result, we can calculate the ages of the various characteristic beds (including fossil zones, seismic reflection beds, and marker layers of electrical properties) for any given borehole-section when it was divided into facies, and check the validity of the chronology. According to all those studies, the stratigraphic and geochronologic analysis program of the Quaternary deposits in the Qaidam Basin has permitted a detailed discussion to be made in this paper.     

A NEW SYSTEM FOR THE SYNTHESIS OF HIGH LEVELS OF HBsAg SEQUENCE IN Escherichia coli

Using a system to study promoter activity, we have obtained a promoter fragment from E. coli chromosomal DNA. The HBsAg geno under the control of this promoter could be expressed in E. coli. The expression products are isolated and purified by means of a column of anti-HBs cross-linked to Sepharose 4 B. The pure products are characterized through the double diffusion method on 0.6% agarose and polyacrylamido-SDS gel electrophoresis. The synthesis of high levels of HBsAg sequences in E. coli is confirmed.     

THE COMPLETE NUCLEOTIDE SEQUENCE OF THE CLONED DNA OF HEPATITIS B VIRUS SUBTYPE adr IN pADR-1

The complete nucleotide sequence of the cloned hepatitis B virus DNA subtype adr in pADR-1 wasdetermined by Maxam and Gilbert's method. It is 3215 base pairs in size, which is 27 bp longer thanthe sequence of the adr pHBr330, as reported by Ono et al. The nucleotide difference between pADR-1and adr pHBr330 is about 2% while those between pADR-1 and adw as well as ayw are 9.3% and 9.7%respectively. In this paper, the heterogeneity and homogeneity of the S gene, the C gene and the othercoding regions in pADR-1 and in the other subtypes are compared and discussed.     

THE PARAMETER KERNELS FOR THE LINEAR INVERSION OF THE FREE OSCILLATION OF THE EARTH (Ⅱ)

This is the second instalment of the paper, in which the method of derivation of the for-mulas of parameter kernels for the spheroidal oscillations are considered. The principle ofRayleigh is used to derive the formulas of the kernels of the two elastic parameters, i.e. μand λ. But for that of ρ, it is found very difficult to get satisfactory results. A new butsimpler approach is followed and very satisfactory results are obtained.