盐溶质及其离子品位空间变异性的 Co-Kriging 估计

根据土壤特性的空间变异性和大型灌区水盐监测需要，本文用多元地质统计学（ＭＶＧ）的Ｃｏ—Ｋｒｉｇｉｎｇ（ＣＫ）方法，研究了引黄灌区内２种尺度条件下Ｓｏ２－４—Ｃｌ－型盐渍化土壤盐溶质及其主要离子品位的协同估计，用３种单变量和一组多变量预测主变量信息不足时的不同目标，结果表明：用野外易测的ＥＣ值可精确估计Ｃｌ－；用ＥＣ＆Ｃｌ－组成的多变量可估计较难测定的Ｋ＋＋Ｎａ＋品位；由小尺度获得的ＣＫ模型可精确用于中尺度估计并对求解ＣＫ方程的有关技术作了探讨，有助于ＭＶＧ理论在土壤—水科学领域的应用与开拓．

干旱区稳定蒸发条件下土壤盐溶质迁移的动态预测

1.导言土壤盐碱化是世界干旱区共同性的问题,也是人类遇到的最古老的环境问题。近30年来,迫于人口压力和食物需求,许多容易开发的土地均已得到利用,人们正在将注意力转向干旱区。由于干旱区自身的特征,土地开发和盐渍化防治,在强烈蒸发条件下土壤盐溶质浓度目标C(Z,t)及迁移预测已成为近代土壤—水环境研究热点之一。

混合溶剂盐化学制冷剂的研究

研究表明 ,用 Na2 CO3· 1 0 H2 O和 Na2 HPO4· 1 2 H2 O混合物作溶剂盐较单独使用 Na2 HPO4·1 2 H2 O或 Na2 CO3· 1 0 H2 O作溶剂盐 ,其制冷效果更佳 .适当增加混合溶剂盐中 Na2 HPO4· 1 2 H2 O的量 ,可延长制冷时间 ,降低制冷温度 .

新型化学制冷剂的研究

研究表明Na2 CO3·10H2 O和Na3PO4 ·12H2 O混合物作溶剂盐较单独使用Na2 CO3·10H2 O或Na3PO4 ·12H2 O作溶剂盐 ,其制冷效果更佳 ,制冷时间更长 ,制冷温度更低。

Preparation and characterization of poly(lithium acrylate-arcylonitrile)/LiClO_4-LiNO_3-LiBr solid polymer electrolytes

Through orthogonal experiment, a new type of LiClO4-LiNO3-LiBr eutectic salt with optimum mole ratio of n（LiClO4）∶n（LiNO3）∶n（LiBr）=1.6∶3.8∶1.0 was prepared. The poly（lithium acrylate-acrylonitrile）/LiClO4-LiNO3-LiBr solid polymer electrolytes were prepared with poly（lithium acrylate-acrylonitrile） and （LiClO4-LiNO3-LiBr） eutectic salts. The effect of LiClO4-LiNO3-LiBr eutectic salts content on the conductivity of solid polymer electrolytes was studied by alternating current impedance method, and the structures of eutectic salts and solid polymer electrolytes were characterized by differential thermal analysis, infrared spectroscopy and X-ray diffractometry. The results show that the room temperature conductivity of LiClO4-LiNO3-LiBr eutectic salts reaches (3.11×10-4 S·cm-1.) The poly（lithium acrylate-acrylonitrile）/LiClO4-LiNO3-LiBr solid polymer electrolytes possess the highest room temperature conductivity at 70% LiClO4-LiNO3-LiBr eutectic salts content, and exhibit lower glass transition temperature of 75 ℃ compared with that of poly（lithium acrylate-acrylonitrile） of 105 ℃. A complex may be formed in the solid polymer electrolytes from the differential thermal analysis and infrared spectroscopy analysis. X-ray diffraction results show that the poly（lithium acrylate-acrylonitrile） can suppress the crystallization of eutectic salts in this system.

Molecular Thermodynamic Model for Polyelectrolyte Solutions with Added Salts

A molecular thermodynamic model of polyelectrolyte developed previously was extended to polyelectrolyte solutions with added salts.Thermodynamic properties,such as activity coefficients of polyelectrolytes or added salts and osmotic coefficients of solvent, of a number of aqueous mixtures of polyelectrolytes and salts are analyzed with the proposed model.Successful correlation is obtained in the range of moderate or higher polyion concentration.For the same sample,thermodynamic properties of polyelectrolytes with and without simple electrolytes can be predicted mutually using parameters from regression data.

Preparation of jarosite by Acidithiobacillus ferrooxidans oxidation

The formation ofjarosite in the presence of Acidithiobacillusferrooxidans （A. ferrooxidans） was researched to ascertain the conditions of producing minimum precipitation. The effects of salt concentration and pH on the characteristics ofjarosite formed in K2SO4/（NHa）2SOa-FeSO4 inorganic salt solution and 9K medium were studied by using the measurements of scanning electron microscope, X-ray diffraction, Fourierism transform infrared analysis, thermogravity/differential thermogravity analysis and particle size analysis to evaluate the product. The results indicate that the formation of jarosite begins when A. ferrooxidans reaches logarithmic growth phase in 9K medium, and a higher pH value is beneficial to the formation of jarosite. The jarosite formed in 9K medium has smaller and more concentrative particle size and smoother surface than that formed in inorganic salt solution.

Influence of Temperature on the Performance of Forward Osmosis Using Ammonium Bicarbonate as Draw Solute

This study investigated the influence of temperature on the performance of forward osmosis(FO) under the condition that the feed solution(FS) temperature was diff erent from draw solution(DS) temperature. An FO model considering the mass and heat transfer between FS and DS was developed, and the FO experiment with ammonium bicarbonate solution as DS and sodium chloride solution as FS was carried out. The predicted water flux and reverse draw solute flux using the developed model coincided with the experimental fluxes. Increases in the temperature of FS or DS yield corresponding increases in the water flux, reverse draw solute flux, and forward rejection of feed solute. Compared with increasing the FS temperature, increasing the DS temperature has a more significant impact on enhancing FO performance. When the temperature of DS increased from 20 to 40 ℃, the specific reverse solute flux decreased from 0.231 to 0.190 mol/L.

Modeling and simulation of neodymium oxide dissolution in molten fluorides

By combining the mass transfer mechanism of neodymium oxide with dissolution kinetics,a solution strategy for neodymium oxide dissolution was proposed to predict the dissolved neodymium oxide concentration during the process under complex flow field conditions.The factors affecting neodymium oxide dissolution were analyzed in detail.Aiming at the pulse feeding and continuous feeding modes in industrial practice,the characteristics of the dissolution process under the two feeding modes were compared.Simulation results showed that pulse feeding took shorter time to distribute evenly than continuous feeding.Finally,the dissolution time of single-particle neodymium oxide under static flow field conditions was compared with the literature results.Except for only one set of data with a maximum error of about 10%,the errors of other data are all within 5%.

The Clinical Randomized Controlled Trial on the Safety and Efficacy of Polyethersulfone Membrane Dialyzer in the Maintenance of Hemodialysis Patients

Objective： To observe the safety and efficacy of polyethersulfone membrane dialyzer used by chronic renal failure patients in clinical maintenance hemodialysis （MHD）. Methods： From January to February 2009, 36 patients were recruited from Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. The experiment was approved by the ethnical committee of Xinhua Hospital and under permissions fronl patients. All the patients were randomized into polyethersulfone group （PES, n=18） and polysulfone group （PS, n=18）. Hemodialysis was given by using Fresenius 4008S capacity-controlled dialyser and ultra-purified bicarbonate dialysate, more than 3.5 h each time, three times per-week, followed by heparin anticoagulation for a week, three times totally. Changes in blood urea nitrogen （BUN）, serum creatinine （Set）, phosphate （p2＋）, hemoglobin and albumin levels were determined for the efficacy and safety evahlation. Results： The serum BUN, Set and p2＋ concentrations significantly reduced after hemodialysis with different dialyzers, and the decrease amplitude of two groups was equivalent（P〉0.05）. The clearance rate of the serum BUN and Scr had no significant difference among two groups（P〉O.05）. The clearance rate （ml/min） of the sermn P^2＋ was 144.57 ±27.83 v.s. 117.15 ±22.77 in two groups. The clearance rate of the serum p^2＋ in PES group was more than that in PS group, and the difference was significant between two groups （P=0.0001）. It was indicated that PES and PS membrane could efficiently eliminate serum mieromolecule solute in MHD patients, so PES membrane excelled PS membrane in eliminating serum p2＋. The hemodialysis safety index, for example serum hemoglobin, albumin and blood pressure, had no significant difference between the two groups before and after hemodialysis （P〉0.05）. Conclusion： The efficacy and safety of the PES hollow fiber membrane dialyzer is equivalent to that of the imported PS membrane dialyzer in hemodialysis for MHD patients. The PES membrane excels PS membrane in eliminating sermn p^2＋.

The Desalting Property of Ion-Exchange Resins in Organic Solvent

the desalting property of ion-exchange resins in organic solventis reported by using potassium acetate as a model compound. Theexperimental results show that solvability of the solvent, stirringspeed, and temperature are the factors which influence theion-exchange rate. The increase of solvability, stirring speed andtemperature will speed up the ion-exchange process.

Infrared Absorption Intensity Analysis as a New Tool for Investigation of Salt Effect on Proteins

The native protein structures in buffer solution are maintained by the electrostatic force as well as the hydrophobic force, salt ions play an important role in maintaining the protein native structures, and their effect on the protein stability has attracted tremendous interests. Infrared spectroscopy has been generally used in molecular structure analysis due to its fingerprint resolution for different species including macromolecules as proteins. However spectral intensities have received much less attention than the vibrational frequencies. Here we report that the spectral intensities of protein amide I band, the finger prints for the protein secondary structures, are very sensitive to the local electric field known as Onsager reaction field caused by salt ions. IR absorbance thermal titrations have been conducted for a series of samples including simple water soluble amino acids, water soluble monomeric protein cytochrome c and dimeric protein DsbC and its single-site mutant G49R. We found that at lower temperature range （10-20℃）, there exists a thermal activated salting-in process, where the IR intensity increases with a rise in the temperature, corresponding to the ions binding of the hydrophobic surface of protein. This process is absent for the amino acids. When further raising the temperature, the IR intensity decreases, this is interpreted as the thermal activated breaking of the ion-protein surface binding. Applying Van＇t Hoff plot to the thermal titration curves, the thermodynamic parameters such as AH and AS for salting-in and ion unbinding processes can be derived for various protein secondary structural components, revealing quantitatively the extent of hydrophobic interaction as well as the strength of the ion-protein binding.

Impact of Lignosulfonate on Solution Chemistry and Phospholipid Fatty Acid Composition in Soils

An incubation experiment(Exp. 1) with three soils, two from Australia and one from Norway, was carried out to investigate the fate of dissolved BorreGro(a lignosulfonate, produced by Borregaard LignoTech Company, Norway) at different concentrations(0, 10 and 100 mg C L-1) in soil solutions. A rhizobox experiment(Exp. 2) was also done in a Norwegian clay soil, mixed with four levels of BorreGro-carbon(BG-C) added(0, 2, 20 and 200 mg BG-C kg-1) to test the impact of BorreGro on root growth, rhizosphere chemistry(pH, metals and dissolved organic carbon(DOC)) and the composition of phospholipid fatty acids(PLFAs). The BorreGro addition increased the concentration of Mn due to the high concentrations in BorreGro. The BorreGro addition to soil had an indirect but significant impact on the rhizosphere chemistry and PLFAs. The lowest amounts of added BorreGro facilitated the DOC excretion at plant roots, and thereby increased the bacterial and fungal biomass, likely as an effect of increased Mn solubility from BorreGro in the root zone.