Membrane mirror and bias electronics

We have designed and built an electrostatically deformable membrane mirror with simple bias and driver electronics to evaluate its suitability for a curvature-sensing adaptive optics system. It has a 100-mm-diameter aluminized nitrocellulose membrane, with 31 actuators arranged concentrically. The unit operates at atmospheric pressure with a high bias voltage applied to the membrane. The high-voltage electronics are contained within the mirror housing for safety reasons. An entrance window reduces the effects of air-coupled vibration. Details of the device and design rationale are presented. With a proper bias, the unit can provide low-order (including tip-tilt) wave-front correction.     

白肋烟烟碱含量的化学调控技术研究

2000~2001年研究了化学物质2,4-D、吲哚类物质、丙二酸和乙烯利及其混配剂对白肋烟烟碱合成、烟叶产量、产值及评吸质量的影响,结果表明,2,4-D、吲哚类物质及吲哚类物质和丙二酸的混配剂能显著降低白肋烟烟碱含量,改善评吸质量;与对照相比,上部叶烟碱下降0.89~3.42个百分点,降幅达12.95%~49.78%;中部叶烟碱下降1.77~3.81个百分点,降幅达24.25%~52.19%;2,4-D和丙二酸的混配剂及丙二酸单用能降低烟碱含量,但幅度不大。所有处理对烟叶产值、产量无明显不利影响。通过这一研究,基本确定了降低白肋烟烟碱含量、提高其可用性的有效化学调控技术。      

[60]Fullerene Amino Acids and Related Derivatives

This paper is a review of the literature concerning the preparation of [60]fullerene amino acid and peptide derivatives. The structure and applications of these derivatives to the biological and Material sciences is also presented.     

Printing on vinyl—part II. FTIR and TOF‐SIMS studies

Earlier surface analysis studies have suggested that, at least in some situations, the print adhesion properties of barium/zinc stabilized, stearic acid‐lubricated PVC are influenced by the migration (exudation) of a barium/zinc stearate complex. This paper expands the previous study in attempts to reproduce the effects observed on samples of commercially produced films, explain the origin of the migrating specie, and identify the variables that influence the extent to which the phenomenon occurs. The effects of different lubricants, stabilizers, and processing conditions are studied. Mechanistic work suggests that a revised hypothesis is appropriate and that the hydrolyzed complex is actually formed in the PVC matrix and not at the surface.     

RNA polymerase II transcription initiation: a structural view

The emergence of new strains of Vibrio Cholerae has added a new dimension to the variability in pathogenicity and potential virulence of the organisms precipitating diarrhoeal diseases. Considering the shifting patterns of V. cholerae 01 there is a continuous need to monitor the strain characteristics. In this study total 541 stool specimens of acute secretory diarrhoea were investigated between May 1992 and November 1994 for strains of Vibrio Cholerae and anti-microbial susceptibility testing of all the confirmed V. Cholerae strains. In 1992, 50 of the 125 strains (40%) were positive for V. cholerae 01 predominantly biotype El Tor serotype ogawa, and 10 (80%) of non 01 type, with most strains susceptible to tetracycline (100%), chloramphenicol (98%) and Cotrimoxazole (98%), but all resistant to polymyxin B and furazolidine. In 1993, 44 (43.6%) of the 010 strains were positive for V. cholerae 0139 and the rest V. cholerae 01. In 1994, another sero group of V. cholerae 010 emerged, with 42 (13.3%) being positive. Isolates did not agglutinate with any of these antisera and have been labelled as 'other than non-01 vibrio cholerae'.     

氮磷钾营养与白肋烟叶内有关生化物质的关系

研究了大田期氮磷钾营养及配比对白肋烟中有关保护酶的影响及相关物质的动态。结果表明,过氧化物酶(POD)活性与脯氨酸(Pro)含量在烟株生长前期表现为上升趋势、后期呈现下降趋势,峰期出现在移栽后65d左右;多酚氧化酶(PPO)活性与总酚、类黄酮的含量变化呈现出随生育进程的推进而增加的单峰曲线,至移栽后75d达到高峰后回落;丙二醛(MDA)含量也随生育进程的推进而上升,总游离氨基酸(AA)含量则随生育进程的推进而逐渐下降。氮磷钾施用量与白肋烟内原保护酶活性及相关物质含量均呈正相关,N与总酚含量的相关性达极显著水平,N与POD、Pro、PPO和淀粉酶含量的相关性达显著水平。三元素对白肋烟中几种保护酶活性及相关物质含量的影响程度不完全相同,对PPO、Pro、总游离氨基酸和淀粉酶的影响程度为:N>P>K;对MDA、类黄酮含量的影响:K>N>P;对POD和总酚的影响:N>K>P。     

田间集水技术试验初报

为解决湖北烟区灌溉的水源问题,研究了烟草田间的集水方法。结果表明,在田间建集水坑,在垄间覆膜作集水面是一种有效的集水方法,集水量大,建造简单,成本低,易于推广。在鄂西南烟区降雨量大的条件下,抗旱目标一般确定为15d,每667m2垄沟覆膜30m2作集水面,建总蓄水量为4m3的几个集水坑即可满足灌溉需求。     

CO2 bubble nucleation in polystyrene: Experimental and modeling studies

Polymer foams are used extensively in a variety of applications. A firm understanding of bubble nucleation is vital to predict foam properties based on process conditions. However, a number of theoretical and experimental challenges have thus far limited progress in this area. We propose the use of a scaling theory to connect nucleation behavior to well understood bulk phase behavior of polystyrene-CO₂ systems, which can be predicted by equations of state, such as the Sanchez–Lacombe equation of state. Scaling theory of nucleation asserts that when the reversible work of critical nucleus formation is properly normalized and plotted against the normalized degree of supersaturation, the resulting scaling curve is insensitive to temperature and the materials being used. Once the form of the scaling function is known, it can be used to predict the nucleation barrier knowing only the initial foaming conditions and calculating only bulk thermodynamic values. Using an extension of diffuse interface theory, we determined the slope of the scaling curve near saturation. This initial slope allows us to constrain the scaling function for better predictions of the reversible work. We also performed a series of experiments to help verify the accuracy of the scaling theory. The scaled free energy barriers determined from our experiments are consistent with the scaling function so constructed, and our theoretical results qualitatively agree with those found previously. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012