易溶盐试验成盐分析探讨

在公路勘察设计中,为确定土的含盐程度和盐渍土的类型,一般只对土里的易溶盐进行测定,但对土易溶盐试验成盐分析进行很少,使得产生病害的成因往往被人们忽视.在目前粗粒土填筑的路基发生盐胀、构造物发生腐蚀的现象越来越多,是应该引起重视的一个重要问题,该文对土易溶盐试验成盐分析进行了探讨.

盐渍土中硫酸钠含量的计算方法探讨

针对目前盐渍土工程勘察中,为利用硫酸钠含量对盐渍土地基的盐胀性做出初步评价,判定盐渍土作为公路、铁路地基或路基填料的可用性,在易溶盐成盐分析的基础上,提出切实可行的硫酸钠含量计算方法。

Analysis of Cost Functions for Retrieving Sea Surface Salinity

Two kinds of Bayesian-based cost functions (i.e., the unconstrained cost function and parameter-constrained cost function) are investigated for retrieving the sea surface salinity (SSS). In low SSS regions, we have analyzed the sensitivity of the two cost functions to geophysical parameters. The results show that the unconstrained cost function is valid for retrieving several parameters (including SSS, wind speed and significant wave height), and the constrained cost function, which largely depends on the accuracy of reference values, may lead to large retrieval biases. Furthermore, as a retrieval parameter, the sea surface temperature (SST) can re-sult in the divergence of other geophysical parameters in an unconstrained cost function due to the strong sensitivity of brightness temperature to SST. By using the unconstrained cost function and the simulated brightness temperature TB with white noises, the retrieval biases of SSS are discussed with the following two procedures. Procedure a): the simulated TB values are first averaged, and then SSS is retrieved. Procedure b): the SSS is directly retrieved from the simulated TB , and then the retrieved SSS values are aver-aged. The results indicate that, for low SSS and SST distributions, the SSS retrieval by procedure a) has less biases compared with that by procedure b), while the two procedures give almost the same retrieval results for high SSS and SST sea regions.

Composition and structure of arsenic−antimony alloy electrodeposited from acidic chloride solution

AsSb alloy(0.70−95.81 wt.%As)was prepared by electrodeposition in As(III)and Sb(III)contained electrolytes.The influence of electrolyte composition,hydrochloric acid concentration,and temperature on the composition and structure of AsSb deposits was studied.The electroreduction mechanism of As(III)and Sb(III)in hydrochloric acid solution was revealed via thermodynamic analysis.The results show that the increase of H+concentration promotes the reduction of As(III),while the increase of Cl^(−)concentration significantly inhibits the reduction of Sb(III).As a result,the As content in deposits increases gradually with the increase of hydrochloric acid concentration.Simultaneously,the phase structure of AsSb deposits evolves from crystalline to amorphous.When the As content is 24.55−33.75 wt.%,AsSb mixed crystal is obtained.The electrolysis temperature has little effect on the deposits composition,but the structure of deposits evolves from crystalline to amorphous with decreasing the temperature.

One-dimensional Zigzag Chain Coordination Polymer [Zn(μ-phth)(imi)_2]_∞ Bridged by ο-Phthalato

The reaction of zinc carbonate with o-phthalic acid and imidazole in an aqueous-alcohol solution led to the formation of colorless crystals of [Zn(-phth)(imi)2]∞. Single-crystal X-ray analysis has revealed that the complex crystallizes in a monoclinic system, space group Pn with a = 8.394(2), b = 9.976(3), c = 9.959(3) ? ?= 104.409(4)? V = 807.6(4) ?, Z = 2, C14H12N4O4Zn, Mr = 365.65, Dc = 1.504 g/cm3, ?= 1.544 mm-1, F(000) = 372, the final R = 0.0466 and wR = 0.1171 for 1834 reflections with I >2(I). The complex displays a zigzag infinite chain structure in which each zinc (Ⅱ) center is coordinated by two oxygen atoms and two nitrogen atoms to generate a ZnN2O2 distorted tetrahedral geometry. The neighboring zinc atoms are bridged by the o-phthalate ligand. Each chain is linked by hydrogen bonds with its neighbors to form a three-dimensional coordination polymer.

Surface plasmon resonance analysis to evaluate the importance of heparin sulfate groups＇ binding with human aFGF and bFGF

Human acidic and basic fibroblast growth factors (aFGF and bFGF) are classic and well characterized members of the heparin binding growth factor family. Heparin is generally thought to play an extremely important role in regulating aFGF and bFGF bioactivities through its strong binding with them. In order to unravel the mechanism of the interactions between heparin and FGFs, and evaluate the importance of heparin sulfate groups' binding with FGFs, surface plasmon resonance analyses were performed using IAsys Cuvettes System. Heparin and its regioselectively desulfated derivatives were immobilized on the cuvettes. aFGF and bFGF solutions with different concentrations were pipetted into the cuvettes and the progress of the interaction was monitored in real\|time by Windows based software, yielding kinetic and equilibrium constants for these interactions. In addition, in order to reduce the delicate difference among the cuvettes, inhibition analyses of mixture of FGFs and immobilized native heparin by modified heparins were also done. The data from these two methods were similar, indicating that all sulfate groups at 2 O, 6 O and N in heparin were required for the binding to aFGF; and that their contribution to the binding was in the order 2 O, N and 6 O sulfate group. In contrast, definite contribution of the 6 O sulfate group to the binding with bFGF was most apparent, while the other two sulfate groups appeared to be necessary in the order 2 O and N sulfate group. These methods established here can be used for analysing the effect of sulfate groups in heparin on the binding with other human FGF members or other heparin binding proteins.

Synthesis and Study of Heteronuclear Citrates

Terms of synthesis were determined for creation of new generation premixes and for their testing in experiments. Heteronuclear chelate citrates of general formula： M12MnL2.nH2O （where, M^I = Zn, Co, Fe, Mn, Cu; MH = Mn, Zn, Co, Cu; n = 0/4） were synthesized. Identity and composition of synthesized compounds were defined by microelemental analysis, determination of melting temperature and X-ray diffraction analysis. X-ray diffraction method was used also to define crystallinity of the compounds and their citric acid （H4L） component. X-ray amorphous and iso-structural orders were also revealed.

Synthesis and Study of Glutamine Acid Containing Citrates

Terms of synthesis were defined for the creation of new generation chelate fertilizers and for their experimental testing. Glutamine acid and citric acid containing chelate citrates of the general formulae M.gI.HL＇nHO were synthesized, where, M = Mn, Zn, Fe, Co, Cu; n = 0; 1; 1.5; gl-glutamine acid; HL-citric acid anion. Identity and composition of synthesized compounds were determined by microelemental analysis, melting temperature and X-ray diffraction analysis. X-ray diffraction analysis of the compounds and glutamine acid and citric acid （H4L） was used to determine their crystalline structure and roentgen-amorphous and iso-structural orders. Their solubility was studied in various solvents.

EFFECT OF AMPHIPHILIC POLY (STYRENE-B-ETHYLENE OXIDE) DIBLOCK COPOLYMER INTERCALATED LAYERED SILICATE AS FILLER ON ACRYLONITRILE-BUTADIENE-STYRENE RESIN

The diblock copolymers intercalated layered silicate was prepared via a melt dispersion technique. Then the effect of intercalated hybrid as filler on acrylonitrile- butadiene-styrene resin was characterized by X-ray diffraction, transmission electron microscopy, stress-strain measurements in elongation.