THE HUANGHAI SEA IN THE LAST GLACIAL PERIOD——ACQUISITION AND STUDY OF SOME NEW DATA ON ITS PALEOGEOGRAPHY

Based on the studies on the sediments of the Huanghai Sea (Yellow Sea) formed in thelast glacial period, the complicated palaeogeographic environments of the Huanghai Sea arefound. By the data newly found in the peat and shell layers, it is revealed that the HuanghaiSea is three times exposed and dried as a continent. And the marine sediments are foundfor the first time in the so-called "continental sediment" formed in the early of thelast glacial period. The evolutionary pattern and geological chronicle of natural environ-ments of the Huanghai Sea can primarily be established by the facts that the reversed polarevents of palaeomagnetic variations in the cores are determined and that the peat layer isdated by using ~(14)C.     

SYNTHESIS AND CHARACTERIZATION OF BLOCK POLYMER OF ALTERNATING COPOLYMERS

Block polymer of alternating copolymers, poly[(ST-a-MA)-b(IP-a-MMA)-b-(ST-a-MA)](I), has been synthesized in the presence of AlEt_(1.5)Cl_(1.5),by using Mn_2(CO)_(10)/CBr_4. initiation system.The GPC results indicate that there is no unreacted prepolymer in I purified by precipitation andfractionation. The study of NMR shows that every block of polymer I has alternating structure. The dynamicmechanical properties of I measured by torsional braid method indicate that the polymer has two T_g s,being 38 and 75℃, respectively. The transmission electron micrographs of I show they have two phasestructure and the domain size increases with increasing molecular weight of hard block.     

DROUGHT-EARTHQUAKE RELATION AND MEDIUM-RANGE PREDICTION OF GREAT EARTHQUAKES

In order to approach the medium-range prediction of great earthquakes with Ms≥6, the author investigated the relation between drought and earthquakes and believed that the drought-earthquake relation is an effective method for the medinm-range prediction of great earthquakes.When the author studied the meteorological effects on the earthquake preparation, he found that the epiecntral regions of great earthquakes with M≥6 are usually dry for one to three and a half years before earthquakes. The draught area changes with the earthquake magnitude proportionally. If an earthquake occurs in the 3rd year of drought, its magnitude is 0.5 higher than that in the 1st year of the drought.According to the above-mentioned facts, the author puts forth the medium-range prediction method and principle of great earthquakes by the drought-earthquake relation: (ⅰ) the magnitude is defined in accordnce with the area of the drought regious; (ⅱ) the possible risk area is defined on the basis of the location of the droug     

PRINCIPLE OF REMOTE SENSING OF ATMOSPHERIC AEROSOL SIZE DISTRIBUTION BY COMBINED SOLAR EXTINCTION AND FORWARD SCATTERING METHOD AND NUMERICAL EXPERIMENT

In this paper, the principle of inverting aerosol size distribution by solar spectral extinc-tion-forward scattering measurements is proposed and analyzed. Two methods of inversion——the segmental inversion and the combined one——are presented. Numerical experimentsshow that this method is quite successful in improving the accuracy of retrieved aerosolsize distribution in both smaller part (r<1μm) and larger part (r>1μm) of aerosolsize ranges.     

FORMATION AND DEVELOPMENT OF TAIHU LAKE AND RECENT DEPOSITION

Situated in the Taihu plain between the mouth of the Changjiang River and theHangzhou Bay, the Taihu Lake is a large shallow-water lake in China with a surface area of 2427.8 km~2.The lake bottom mainly consists of loess-like sediment. Some buried and silted up channels and residual depressions can be found at the bottom and a lot of Neolithic cultural relics on the loess-like sediment. This indicated that the Taihu Lake was formed on the alluvial plain charaterized by widely deposited loess-like sediment because of siltation and stagnancy of water, instead of by development from lagoons as reported in the past.Recent deposition including influent-effluent current accumulation, wind-driven current and storm deposition in this lake occurred mainly in the south, the west shore and the midst of the lake.The sedimentary rate in the east Taihu Lake is about 1.7-1.8 mm/a, whereas in the west Taihu Lake it is about 0.41 ram/a, only 23％ of that of the former.     

CLONING AND ANALYSIS OF HISTONE 3 GENE AND RUBISCO SMALL SUBUNIT GENE OF RICE

We have isolated and determined the DNA sequence of several genes from the nucleus of rice (Oryza sativa, IR26). We screened a genomic library of rice IR26 and isolated a 14.8 kb segment containing an H3 gene and an H3-like pseudogene. Sequence analysis showed that the coding sequence of the rice H3 gene is 405 bp in length, and the 5' and 3' noncoding regions contain several regulatory sequences common to eukaryotic or histone genes. The codon usage of the rice H3 gene is highly unusual in that the third codon position is 98% G and C. Southern blotting analysis suggested that the copy number of the H3 gene is around 50 per diploid rice genuine. From the same rice geaomic library, we have identified rbcS, which codes for the small subunit of ribulose-1, 5-bisphosphate carboxylase-oxygenase (Rubisco). The rbcS sequence is interrupted by an intron at the same location in both rice and wheat. The first 18 amino acids of the transit peptide in rice and wheat rbcS are identical     

EFFECTS OF MOIST PROCESS ON SUBTROPICAL FLOW PATTERNS AND MULTIPLE EQUILIBRIUM STATES

A low-order general circulation moisture model is presented, and some experiments with it are described. The model is based on the quasi-geostrophic motion in the β-plane of two layers with landsea distribution. As proposed by Lorenz, the moisture variable in the model is the total dewpoint. Modeled processes consist of evaporation, precipitation, and the effects of clouds and water vapor on radiation.Results of the experiments with the model show that the moisture process enhances subtropical highs significantly and the meridional development of flow. It can also reproduce the hi-equilibrium states in certain parametric combinations, which is similar to the observational fact about the "Eastern pattern" and the "Western pattern" circulations in the subtropical areas during the summer half year.     

EFFECTS OF MOIST PROCESSES ON LOW-FREQUENCY OSCILLATIONS OF GENERAL CIRCULATION OVER NORTHERN HEMISPHERE DURING SUMMER TIME

In this paper the Lorenz's moist low-order spectral model~([1]) is further improved by introducinga parameterization for cumulus convection into it. Numerical experiments by this improved model mani-fest quasi-three week oscillations both in the location of the simulated subtropical high at upper tropo-sphere along cast-west direction and in the simulated vertical velocities and precipitation over South Asia,which is similar to those in the real atmosphere. The results of the experiments and the computationsof parameters of energetics show that introducing moist processes is a necessary condition for stimulat-ing and maintaining the low-frequency oscillations, and that moist convection can also obviously shortenoscillation periods, which is generally in agreement with the conclusions in another paper~([2]) of theauthors.     

SEPARATION OF IRON AND MANGANESE IN THE EARLY DIAGENETIC PROCESSES AND ITS MECHANISM OF BIOGEOCHEMISTRY

Study shows that the reduction of iron (Fe~(3+)) and manganese (Mn~(4+)) in modern sedi-ments and the diffusive flux of the Mn~(2+) from the pore water into the overlying waterare mainly controlled by bacteria, and the distribution of the bacteria is believed to beaffected strongly by the sedimentary environment. It is the diffusive fluxes between Fe~(2+)and Mn~(2+) that lead to the separation of iron and manganese in the modern sediment at theChangjiang Mouth and near the shore. The level of the separation decreases with theincrease of the overlying water salinity and increases from the surface to the depth. Thismechanism has given a new explanation why manganese is concentrated in sediments onthe oceanic floor of ferromanganese-rich nodules.     

DISPERSITY OF THE COPOLYMER OF STYRENE AND 2, 2, 6, 6-TETRAMETHYL-4-PIPERIDINYL-METHACRYLATE (PDS) IN POLYPROPYLENE AND ITS INFLUENCE ON PHOTOSTABILIZING ACTION OF PDS

The morphology of films of PDS/PP blends with various contents of PDS and with PDS of dif-ferent molecular weights was examined by scanning electron microscopy and the photostability ofthese films was studied by infrared spectrometry. Experimental results show that PDS is dispersedin PP matris as spherical globules being in size of the order of 10~(-1)μm when content of PDS is in therange of 0.1 % to 1%. The phase separation of PDS from PP results in decrease in photostabilizingaction of PDS to some extent. It is found that films of PP blended with PDS of different molecularweights show similar morphology and photostabilizing action if the content of PDS is kept constant.     

Correlation Analysis of the Runoff of the Rivers and the Seisms in China

In recent hundred years the annual discharge variations of the Changjiang River (represented by the Yichang station) and the Huanghe River (represented by Shanxian and Tangnaihe, respectively) have closely related to the geographical distribution of the earthquakes coming about in China in the same year, Both the occurrence of the destructive seism or seismic swarm in the river basins and the disappearance of the shocks in the east and south of the basins are the conditions that the Changjiang and Huanghe Rivers are the high flow while that the strong earthquake of magnitude 7 or more occurred in North China is the condition for the Changjiang low flow year and that of 6 or more in the Qilian Mountains area is for the Huanghe River. In the latter part of this paper, a 2-year sample is given to explain that the conditions of the 2 rivers being high flow years are that the north-south seismic belt is active and in the meanwhile no seism occurred in South China, and those of the low flow year are that the     

A STUDY ON THE STRUCTURE AND PROPERTIES OF POLYBUTYLALDEHYDE FORMED IN LOW TEMPERATURE PLASMA

The polybutylaldehyde obtained by plasma polymerization was investigated by means of IR, X-ray diffraction, GC-MS, elementary analysis, TEM, electron diffraction and contact angle measurements etc. The results showed that the polymer formed in plasma is amorphous crosslinked polymer, and its backbone is made of carbon atoms. The surface energy of the polymer film is independent of the polymerization conditions. No addition reaction has taken place in the carbonyl group of butylaldehyde in the plasma condition. The result of the wettability measurements showed that the polymer film is generally hydrophobic and the surface energy of the film is about 41 dyn/cm, in which the dispersion force contribution is the majority. The electron diffraction proved that some crystal substance, even the single crystals were present in the polymer. X-ray diffraction also proved the presence of crystal and showed about 15% crystaUinity fraction.     

STUDIES ON THE RING-OPENING POLYMERIZATION OF TETRAHYDROFURAN Ⅳ. COPOLYMERIZATION OF TETRAHYDROFURAN AND PROPYLENE OXIDE INITIATED BY FUMING SULFURIC ACID AND PERCHLORIC ACID CATALYST SYSTEM

The yield of copolymerization of tetrahydrofuran and propylene oxide (THF:PO=100:5—15, by wt.) using a binary catalyst of fuming sulfuric acid (21% or 28%) and perchloric acid is around 50—60%, and the loss of THF in the reaction is below 10—15%. The average molecular weight of the product can be controlled in the range of 1000—2000 by varying the binary catalyst system. The present method, which is different from the usual copolymerization initiated by BF_3-diol or SbCl_5-diol system, shows the pecularities i.e. the yield of copolymerization with the low PO feed is not decreased, the hydroxyl functionality is equal to 2, and the end-groups are predominantly primary hydroxyls (around 65—70%).     

THE CONFIGURATION OF QUASICRYSTAL UNIT CELL AND DEDUCTION OF QUASILATTICE

From the crystal chemistry and icosahedral phase, two kinds of coordinational polyhedron with 8-fold rotational symmetry——hexakaicahedra and bicapped antiprism were possibly suggested and their one- and two-dimensional quasilattices were deducted. According to the principle of Bravais in conventional crystallography, four kinds of two-dimensional unit cell have been defined in 5, 8, 10, 12-fold rotational symmetry quasicrystal. The authors considered that quasicrystal is a kind of crystal which possesses an incommensurable translational period. This kind of translation is carried out by inflation or deflation symmetry operation.     

NORTHWARD JUMPING OF SUBTROPICAL HIGHS AND CUSP CATASTROPHE

The observational facts show that over a wide range of time and space there exist in the atmosphere a variety of catastrophic phenomena. In this paper, the northward jumping of subtropical highs—a catastrophic phenomenon in the atmosphere—is diseussed on the basis of the catastrophe theory initiated by René Thom as well as the cusp catastrophe model; the mechanism of the gradual change of the controlling parameters leading to the abrupt change of the phenomenon is investigated and thus the well-known phenomenon of the "June catastrophe" of the atmospheric circulation interpreted.Also, it is pointed out, as sometimes immediately conditioned by the change of the geopotential values on the isobaric surface, planetary scale subtropical highs are not necessarily moving and developing as "realistic systems".     

AEROMAGNETIC SURVEY AND GEOLOGICAL STRUCTURE OF OFFSHORE CHINA

This paper discusses the characteristics of the regional geological structure of the Bohai Sea, the Huanghai Sea, the East China Sea and the South China Sea on the basis of the data achieved by aeromagnetic surveys over the past years.The Huanghai Sea is an intercontinental sea which is tectenically similar, and can be connected, to the adjacent continental parts. It is a submerged part of the continent. Aeromagnetic survey shows that the deep structures in this area strike E-W, belonging to the Pal-Asiatic Tectonic Domain. The South China Sea is a typical marginal sea of the Western Pacific Ocean, resulting from the fracturing of the continental margin and the sea floor spreading from the Mid-Oligocene to the Miocene.     

MICROFOSSILS FROM LATE PROTEROZOIC MANGANESE ORE DEPOSITS IN WESTERN HUNAN PROVINCE AND EASTERN GUIZHOU PROVINCE, SOUTH CHINA

Abundant microfossils and organic residuals have been discovered by SEM and normal palynological maceration from manganese ore beds intercalated in late Proterozoic glacial rock units in western Hunan Province and eastern Guizhou Province. Taking isotopic dating into consideration, the age of manganese ore deposits in both regions is suggested to be about 750 Ma. A distinct character is that a great quantity of colonial microfossil——Sphaerocongregus (or Bavlinella) and their degradational variants have been obtained from rhodochrosite. Their biological and biochemical functions, combined with the geochemical effect of manganese in different ways, may play an important role in the manganese cycle.     

SYNTHESIS AND NMR CHARACTERIZATION OF PRECURSORS OF EPOXY NETWORK AS POLYMER HOST FOR SOLID ELECTROLYTE

To raise the room temperature ionic conductivity and improve the mechanical strength of a PEO-based polymer electrolyte, a noncrystalline two-component epoxy electrolyte system has been prepared. The diglycidyl ether of polyethylene glycols as precursors of the system were synthesized by a two-step process. The presumed structure of the product was characterized, by ~(13)C, ~1H NMR and IR spectroscopy. It was found that a side-reaction occurred between the secondary hydroxyl group of PEG-chlorohydrin and epichlorohydrin in some degree, resulting in a by- product containing—CH_2Cl side group. By selecting a characteristic signal, which is undistorted by the increase in the length of CH_2 CH_2—O segment, a ~1H NMR approach of determining the equivalent epoxy weight (EEW) was proposed. The method is valid to specimens even though the EEW is as high as 2,000. The examination of the specimens by DSC showed that epoxidation greatly depressed the crystallinity of the PEG's, whereas the T_g was raised.     

STRUCTURE-PROPERTY RELATIONSHIP OF POLYELECTROLYTES AND ITS APPLICATION IN STABILIZING DRILLING-MUD IN PRESENCE OF SALTS

A new polyelectrolyte (SPU) has been prepared. It can depress the water-loss of drilling-mud much more effective than the commonly used acrylic polyelectrolytes even in 30% NaCl solution. SPU has phenyl group in the backbone with -SO_3~- in the side chain while the acrylic polyelectrolytes have C—C and -COO~- respectively, there exists an intrinsic relationship between the structure of polymer and its tolerance to salts, it has been found: 1) The adsorption amount of polymer on clay is related closely to the flexibility of polymer chain. 2) The salt-tolerance of -SO_3~- is superior to -COO-. 3) Both SPU-mud and HPAN-mud are plastic fluids. The dependence of yield point on salts relates to the molecular weight of polymer and hydration of ionogenic group, which is quite different for SPU-mud and HPAN-mud. 4 ) The extent of raising zeta-potential of base-mud by SPU is greater than by HPAN, but the extent of dropping zeta-potential of SPU-mud by NaCI is smaller than HPAN-mud. According to these results we suppose the salt-tolerance of SPU-mud is attributed mainly to hydration of -SO_3~- and that of HPAN-mud mainly to network structure formed in the drilling-mud.     

GROWTH AND MORPHOLOGY OF POLYMER-ACTIN COMPLEXES

F-actins are semi-flexible polyelectrolytes and can be assembled into large polymer-actin complex with polymorphism through electrostatic interaction with polycations. This study investigates the structural phase behavior and the growth of polymer-actin complexes in terms of its longitudinal and lateral sizes. Our results show that formation of polymer-actin complexes is cooperative, and morphology and growth of polymer-actin complexes depend on polycation species and concentrations of polycation and salt in a constant actin concentration. We found that the longitudinal growth and lateral growth of polymer-actin complexes are dominated by different factors. This induces the structural polymorphism of polymer-actin complexes. Major factors to influence the polymorphism of polymer-actin complexes in polyelectrolyte system have been discussed. Our results indicate that the semi-flexible polyelectrolyte nature of F-actins is important for controlling the morphology and growth of actin architectures in cell.