ORIGINS OF POTASH DEPOSITS IN THE QAIDAM BASIN, CHINA

The Qaidam Basin is a typically continental potash-bearing basin, which is comparatively rare in other countries. The potash deposits are widespread in the Quaternary salt lakes of the mid-western basin. At the same time, there exist many favourable conditions for the formation of potash deposits: (ⅰ)the sufficient source of potassium, (ⅱ) the optimum migration and accumulation processes of potassium, and (ⅲ) proper physico-chemical environments for separating potash salts. Owing to the differences in the supplying conditions for the external water to lake-basin and in the chemical compositions of those salt lake brines, potash deposits of various models and various types were formed.     

PRELIMINARY STUDY ON SEDIMENTARY CHARACTERISTICS AND EVOLUTION OF PALAEOCLI MATE OF QARHAN SALT LAKE IN QAIDAM BASIN

Qarhan salt lake which covers an area of 5800 square kilometres is a large playa in Qaidam basin, Qinghai Province. The salt-bearing layers are usually 40 m thick, the maximum thickness being 73 m.The sedimentation of the lake has the following basle characteristics: (1) The salt-containing layers are principally composed of interbedded halite and clastic sediments, and they are either lacking in sulfate deposits or deficient in carbonate sediments. (ii) The sedimentary differentiation is not sufficient, and all of the halite layers almost contain mud, sand, carbonates and gypsum in varying degrees; there exist mixtures of gypsum and halite in the intercalations of clastic sediments. (iii) The salt-carrying beds are associated with aeolian deposits. The authors found for the first time that Malan loess exists in the salt-bearing layers of Qarhan salt lake.Features of evolution of palaeoclimate: A lot of evaporite deposits had appeared in Qarhan salt lake by the end of Late Pleistocene, 24,000—25,000 ye     

TYPE AND EVOLUTION MODEL OF CONTINENTAL KEROGEN IN THE SONGLIAO BASIN

Based on some composite indices, this paper proposes a classification of kerogen in theSongliao Basin and the four stages of hydrocarbon formation. A model of the evolution ofhydrocarbons in a large lake basin different from the model previously suggested ispresented. It is pointed out hi this paper that in a long subsiding, deep-water structural de-pression of a large eutrophic lake, the source rock formed under rapid, non-compensatoryconditions has the highest potential for petroleum. The thermal evolution of "combined"sapropelic kerogen (type Ⅰ) and the characteristics of petroleum formation are illustrated,The authors predict that the Songliao Basin is promising for further exploration.     

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.     

A PRELIMINARY STUDY ON GENETICS AND TYPE FOR EARTH FOREST IN YUANMOU BASIN

The earth forest is a geomorphic type of the running water found in recent years in China. At some distribution regions of loose or semicemented fluviolacustrine facies strata, owing to scouring of rainstorm runoff, thousands of gullies and ravines and some stretches of earth columns were formed, like a stretch of forest observed at a distance, thus it was named earth forest.The earth forest landform developed the most typically in the Yuanmou Basin, Yunnan Province. Through the study, such as strata of fluviolacustrine facies, neotectonics, geomorphics, soil, climate, vegetation, etc., the authors pointed out the condition for forming the earth forest landform and its five development stages, and then divided it into four types: thin gully-earth gemma type, round basin-earth column type, broad gully column fort type and slope-remaining column type.     

PRELIMINARY RESEARCH ON CLAY MINERALS IN SALT LAKE SEDIMENTS OF CHINA AND ITS SIGNIFICANCE

Most of the clay minerals in salt lakes of China are characterized by illite-chlorite as-semblage, with a minor amount of montmorillonite and kaolinite and so on. There are ob-vious differences between mineral assemblages, relative contents and chemical compositionof clay minerals in salt lakes of different areas and in different sedimentary stages. Clayminerals in these salt lakes are basically allogenic, but transitional origin may also exist.The characteristics of clay minerals in salt lakes are controlled by the arid climatic zone ofChina and the different material supplies of salt lakes. With the data taken from clay miner-al study, the author discusses the relation of sedimentary environment of salt lakes, theregularities of immigration and enrichment of mineralization elements.     

On the Structure of the Arginine-carboxylate Salt Bridge: A Density Functional Theory Study

The arginine-carboxylate salt bridge, which represents about 40% of the pairs of ionic groups within proteins, plays a crucial role in determining the structures and functions of proteins1. Numerous experimental evidences have indicated that this type of salt bridge, which usually includes the arginine-glutamate pair and the arginine-aspartate pair, should stay in a zwitterionic state rather than in a neutral one2. This viewpoint has been widely accepted and in usual it is directly used in the…     

Effect of large-scale reservoir and river regulation/reclama-tion on saltwater intrusion in Qiantang Estuary

By using field salinity data recorded in the Qiantang Estuary for the nearly forty years (which covers the periods before and after the erection of a large-scale reservoir in the watershed and river regulation/reclamation in the estuary) and one-dimensional salt water intrusion modeling, it is shown that the salt water intrusion decreases caused by increased low water discharge for the reservoir, while the intrusion increases for the increased tidal range because of the river regulation/reclamation. The integrate result is that the saltwater intrusion decreases.     

ON OTHER WAVE GUIDE IN STATIONARY PLANETARY WAVE PROPAGATIONS IN WINTER NORTHERN HEMISPHERE

In this paper, the refractive index squared of stationary planetary waves in the isothermalatmosphere is computed theoretically. It has been discovered that there should be the otherwave guide pointing from the lower troposphere in middle and high latitudes toward the uppertroposphere in low latitudes in addition to the polar wave guide in the vertical and lateral pro-pagations of stationary planetary waves in winter. The vertical and lateral propagations of stationary planetary waves responding to an idealiz-ed forcing mechanism, for example, an idealized topography or stationary heat sources overthe Northern Hemisphere have been investigated by means of a quasigeostrophic, steady-state,34-level model with Rayleigh friction, Newtonian cooling effect and the horizontal kinematicthermal diffusivity included in a spherical coordinate system. The computed results have veri-fied that there actually is the other wave guide in the stationary planetary wave propagationsin winter. The vertical distributions of     

PRECONCENTRATION OF TRACE ZINC IN SEAWATER ON CPPI RESIN BY FIA AND ON-LINE DETECTION BY ICP-AFS

A quite new type of chelating resin CarboxymethylatedPolyethylenimine-Polymethylenepolyphenylene Isocyanate(CPPI)is usedfor the preconcentration of Zn from high salt water such as seawater.The preconcentration is controlled through the technique of FlowInjection Analysis(FIA).The concentrated sample solution is thendirectly transferred to an Inductively Coupled Plasma-AtomicFluorescence Spectrometer(ICP-AFS)for determination.The detectionlimit of Zn by the technique is about 0.06 ppb.     

In-situ synthesis of nanoparticles via supersolubilizing micelle self-assembly

In-situ synthesis of nano-particles using the self-assembly of molten salt and super soluble micellae was proposed based on a phenomenon of super solubilization of molten salt in reverse micellae and its self-assembly when the concentration reached up to 95%(w/w).The mechanism of the self-assembly indicates that the self-assembly of molten salt occurs in a reverse micelle where a homogenous phase is established between 5%(w/w)of a surfactant with a VB value of less than 1 and a hydrocarbon spe- cies.This synthesis has some unique features,such as being free of water,highly effective deposition and narrow distribution of particle size.     

STUDIES ON THE ACTIVITY COEFFICIENTS OF NONELECTROLYTES IN AQUEOUS SALT SOLUTIONS——Ⅱ. THE EFFECTS OF SALTS OF FATTY ACIDS AND QUATERNARY AMMONIUM SALTS ON THE SOLUBILITIES OF NAPHTHALENE IN WATER

On the assumption that the salt effect (salting-out or salting-in) representsthe balance of the electrostatic effect between the ion and the water dipole andthe dispersion effect between ion and nonelectrolyte molecule, the solubilitiesof n-valeric acid in five cobaltammimes were studied and reported in article Ⅰof this series. In the present investigation the activity coefficients of naph-thalene in two series of salts are determined spectrophotometrically. The firstseries consists of seven sodium salts of fatty acids (sodium formate to sodiumn-heptylate), differing from one another only by the number of CH_2 groups inthe anions. The second series consists of ammonium bromide and three tetra-     

Sulphonamide Residues in Italian Surface and Drinking Waters: A Small Scale Reconnaissance

The occurrence of antibiotics in the aquatic environment is an important emerging issue due to potential adverse effect of these compounds on ecosystem and human health. For a correct environmental risk assessment there is a need for appropriate analytical methods for monitoring antibiotic residues in a variety of water matrices. This paper describes a method for the determination of eleven sulphonamide compounds in surface and drinking waters using solid-phase extraction and liquid chromatography-tandem mass spectrometry. Recoveries of the analytes in both surface and drinking water matrices at different fortification levels, always exceed 87%; the limits of quantification in surface water samples are between 0.005 and 0.021 μg L⁻¹ depending on the compound, and the interday method precision is less than 12%. Matrix effects were evaluated in drinking and surface water samples. The method has been applied to a small scale reconnaissance of river, lake, mineral and municipal water samples; results indicate the occurrence of sulphonamides in some surface and mineral waters analyzed.     

ICHNOFACIES IN LATE PALEOZOIC DEEP-WATER SLOPE SEDIMENT OF JUNGGAR BASIN AND ITS ENVIRONMENTAL ANALYSIS

This paper mainly discusses 15 kinds of ichnogenus found for the first time in the study area from the water depth distribution, body size of trace fossils and the relationship between sedimentary environment and deep-water ichnofacies, based on the summarizing of the sedimentary character of deep-water slope environment in the study area. According to the relationship between the type of turbidite and the combination of trace fossils, 15 kinds of ichnogenus are divided into two types, transition type Zoophycos ichnofacies and deep-water type Nereites ichnofacies. The former is mainly distributed in the transitional area between proximal to distal area of turbidite and the latter in the distal area.     

CHANGES OF SEDIMENTARY ENVIRONMENT SINCE THE LATE PLEISTOCENE IN VESTFOLD HILLS AREA, ANTARCTICA

The Vestfold Hills area was a shallow-sea sedimentary environment in the interglacial stage (50,000—25,000 yr B.P.) of the last glacial period of the Late Pleistocene, and later became a glaciofluvial environment. This marine sedimentary plain was covered by glaciers at the time of 31,000—11,000 yr B.P. After the last glacial period (6500—3500 yr B.P.), the retreat of ice sheets in this area resulted in the formation of lakes and lagoons, followed by alternating sedimentation of three-times sub-turbidity current and two-times ice-melt water. Sulphate-Glauber salt was deposited in the inland depressions. The advance of the ice sheets in this area during the neo-ice age (2800 yr B.P.) resulted in three parallel moraine terraces consisting of boulders and coarse sands composed mainly of hornblende, and subordinately of garnet and magnetite. During this period a Si-AL-chloride detrital weathering crust was developed on hyperthenite with schistose actinolite. In addition to physical weathering (e.g. frost     

VISCOMETRIC INVESTIGATIONS OF POLYVINYLPYRROLIDONE IN MIXED SOLVENTS AND WITH VARYING TEMPERATURE

The viscosity behavior of polyvinylpyrrolidone (PVP) has been determined at 25℃ in mixed solvents comprising water/dimethylformamide (DMF) and water /methanol (MeOH). Analysis of the data has considered the PVP as being both host and guest polymer in solution. The intrinsic viscosity of PVP in DMF is higher than in water and in MeOH, but also increases in a mixed solvent with high water content because of the effect of polymer-solvent interactions. It was also found that the intrinsic viscosity of PVP at finite concentration, [ηpvp]c decreases with an increase in the concentration of PVP in solution. The viscosity behavior of PVP in a mixed solvent is affected by the concentration-dependent intermolecular excluded volume effect, which can be quantitatively expressed by the parameter, bY, which reflects the shrinkage of PVP chain coils, resulting in a decrease of [ηpvp]c. The effect of temperature on the viscosity behavior of PVP in MeOH shows that the interaction parameter increases up to a maximum value, and then decreases after a certain temperature.     

Rapid—In—situ Determination of Chromium （VI） in Water Using Modified Diphenylcarbazine with Citrate

In recent years, the determination of Cr (VI) has attracted great attention because of its toxicity to human, plants and animals1-5. Usually, in the industrial waste water, the concentration of Cr (VI) is relatively high and should be determined frequently. So, an accurate, quick, and convenient method for the measurement of Cr (VI) in environmental water, as well as in river, lake, sea and tap water, is of great importance. The method for determination of Cr (VI) by diphenylcarbazine …     

GEOCHEMISTRY OF SEDIMENTS AND ENVIRONMENT IN XIHU LAKE OF GREAT WALL STATION OF CHINA, ANTARCTICA

The determined results in this paper, which were obtained by the multielement analysis of the 260 cm-deep core sediments under the water of Xihu Lake in the Great Wall Station area, are as follows: The Cenozoic volcanic rocks around Xihu Lake are the main source of sediments in the lake. The chemical differentiation in very fine particles is still detectable. From the variation of ratios of the Cs/Rb, Br/CI and La/Yb in the clay fraction with depth and from the variation or CaCO_3 contained in the sediments, cation replacing amount in the clay grains and the sediment grain sizes in time, it can be seen that since 3600 a. B. P., there has existed the climatic variation of warm-cold-warm, which embodies the advance and retreat history of the ice sheet in this area.     

Bi-salt electrolyte for aqueous rechargeable aluminum battery

The exertion of superior high-energy density based on multivalent ions transfer of rechargeable aluminum batteries is greatly hindered by limited electrochemical stability window of typical water in salt electrolyte(Wi SE). Recently, it is reported that a second salt addition to the Wi SE can offer further suppression of water activities, and achieves a much wider electrochemical window compared with aqueous Wi SE electrolytes. Hence, we demonstrate a class of water in bi-salt electrolyte contai...     

Distribution of Helium Isotopes in Western Pacific Upper Layer

3He/4He ratios in samples of sea water obtained at depths from surface to 300 m in the upper layer of the Western Pacific Ocean were measured by a mass spectrometer VG5400. The lateral and vertical distribution of He isotopes in the studied area was discussed in detail on the basis of 3He/4He ratios. Excess and depleted 3He. in relation to δ3He value of surface water in equilibrium with air has been discussed in the area, which may be mainly attributed to the incorporation of the North Pacific Intermediate Water with the Equatorial Upwelling and the exchange of water masses between the South China Sea and the Western Pacific, respectively. The present work in Western Pacific has also indicated that He isotopes may be used as a tracer for mixing processes of water masses and oceanic circulation.