星型支化聚苯乙烯在四氢呋喃溶液中的形态和溶液性质

通过原子转移自由基聚合制备不同臂长的三臂和四臂星型支化聚苯乙烯(PS),采用示差折光指数(RI)/多角度光散射(MALLS)/毛细管黏度(DV)三检测器联用凝胶渗透色谱对不同臂结构星型PS在四氢呋喃中的形态和溶液性质进行了研究。结果表明,星型支化PS的线团尺寸及特性黏数均低于相同分子量的线型PS,臂数越多,线团紧密程度越大,旋转半径及特性黏数随分子量增加而增大的幅度越小。与线型PS相比,星型支化PS的Mark-Houwink-Sakurada(MHS)方程参数K、α表现出较强的分子量依赖性。

疏水缔合类聚丙烯酰胺溶液性质研究

综述了疏水缔合类聚丙烯酰胺溶液性质的影响因素以及测定溶液微观形态的研究方法

Effect of Osmotic Pressure on Mycoplasma hyopneumoniae Strain 168

[Objective] This study aimed to investigate the effect of hypertonic solution on the morphology,size,incubation time and cell viability of Mycoplasma hyopneumoniae（Mhp）.[Method] Mhp was stimulated by using NaCl hypertonic solution with a final concentration of 1.8% for 1,2,4,6 and 8 min,respectively.After staining and microscopic examination,the particle size and CCU（color change unit） were determined,and PCR identification was conducted.[Result] After treated with hypertonic solution for different time,Mhp was shrunken and turned round,the particle size was reduced,and the cell number rapidly decreased or even disappeared after 2 min.CCU was reduced by a gradient,and the observation time was extended for 1 d.The target band of Mhp could be amplified from samples after treated with hypertonic solution for different time.After treated with 1.8% NaCl solution for 1-6 min,Mhp changed in the morphology and size but still had viability.[Conclusion] This study provided reference data for exploring the entrance of Mhp into blood circulation after intramuscular injection and a new immunization route of swine Mycoplasma pneumonia vaccine.

Effects of root oxidation ability and P on As mobility and bioavailability in rice

The effects of root oxidization ability and P fertilization on As mobility in soils, and subsequently As uptake, translocation and speciation in rice plants were investigated. Results show that root oxidation significantly influences As mobility in rhizoshphere.Genotype TD71 with higher radial oxygen loss(ROL) induces more Fe plaque formation and sequesters more As and P in iron plaque and rhizoshphere soil, leading to the reduction of As accumulation in rice plants. Additionally, P addition mobilizes As in soil solution, and increases As accumulation in rice plants. Arsenic speciation results show that the majority of As species in husks detected is inorganic As, accounting for 82%-93% of the total As, while in grains the majority of As is inorganic As and dimethyl arsenic(DMA), with DMA accounting for 33%-64% of the total As. The fraction of inorganic As decreases while fraction of DMA increases, with increasing As and P concentrations. The study further elucidates the mechanisms involved in effects of ROL on As tolerance and accumulation in rice.

Tuning the Morphology of Pharmaceutical Compounds via Model Based Solvent Selection

In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model. A three-stage approach involving a pre-design stage, a product design stage and a post-design experimental verification stage is presented. The pre-design stage addresses the tormulation of the property constraint tor crystal morphology. This involves crystallization experiments aria development of property models and constraints for morphology. In the design stage various property requirements for the solvent along with crystal morphology are considered and the product design problem is formulated as a mixed integer nonlinear programming model.The design stage provides an optimal solvent/list of candidate solvents. Similar to the pre-design stage, in the post design experimental verification stage, the morphology of the crystals （precipitated from the designed solvent） is verified through crystallization experiments followed by product characterization via scanni＇ng electron microscopy, powder X-ray diffraction imaging and Fourier transform spectra analysis.

Effect of 3-aminotriazole on the corrosion of copper in polluted and unpolluted media

The inhibition of copper corrosion in unpolluted or polluted 3.5% NaCl solution in the absence and presence of 3-amino-1, 2, 4-triazole （ATA） as a corrosion inhibitor was studied by using different electrochemical techniques. Aminotriazole （ATA） is well known as corrosion inhibitor for corrosion of copper and aluminum in unpolluted salt water. The influence of 3-aminotriazole （ATA） on the corrosion behavior of copper in unpolluted and polluted environment has been studied using potentiodynamie and potentiostatic polarization methods. Surface morphological examinations such as SEM, EDS and XPS have also been carried out to understand the mechanism of inhibition of corrosion. Electrochemical measurements and morphological results are clearly show that the inhibitor is strongly adsorbed on the copper surface and form a protective film on the copper surface.

Adsorption Kinetics of Decanoyl-N-methylglucamine at the Expanding Spherical Surface

A general expression of the dynamic surface adsorption [Г（t）] on the expanding spherical surface was derived by solving the corresponding diffusion equation under different initial and boundary conditions. Different from the result of the still spherical surface, two factors （smaller than 1） appeared in the equation for the short time adsorption. Using the derived results, the adsorption kinetics of aqueous decanoyl-N-methylglucamine （Mega-10） solution was studied. In the short time region （t→0）, a good agreement of experimental results with the theory was reached and the adsorption was controlled by diffusion.

Solvothermal Route to Prepare the Metastable Phase 3c-Fe_7S_8 with Hexagonal Platelet Morphology

The metastable phase 3c-Fe7S8 with the hexagonal platelet morphology has been prepared by using solvothermal route. The product was characterized by means of X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS). The experiment results show that the as-prepared Fe7S8 is a metastable phase with the hexagonal platelet morphology.