Influence of Two Salicylate Components on the Particle Size of an Oil-in-Water Emulsion with Nonionic Surfactants

This paper reports a study undertaken using techniques of static and dynamic light scattering to investigate the influence of sodium salicylate and methyl salicylate on droplet size of oil-in-water emulsions. The rates of changes were measured by determining the size and distribution of the oil droplet in the material. All emulsions showed a bimodal size distribution; the mean diameters and polydispersity were calculated from intensity. These data were analyzed with nonlinear regressions and bootstrap methodology. An amount of methyl salicylate component induced a decrease of mean diameter and standard deviation. On the contrary, sodium salicylate entailed the growth of all droplet populations and coalescence for the highest concentration.     

Probing acid sites in MAPO-36 by solid state NMR

An ordering of magnesium is observed in the as-synthesized MAPO-36 molecular sieve. Upon calcination, part of the magnesium is removed from the sample and part occupies extraframework positions thus rendering a random distribution of magnesium in the lattice. The shoulder observed in the³¹P spectrum of the calcined sample is assigned to P(3Al, 1Mg) sites in conflict with the earlier assignment to P-OH groups. The bridging hydroxyl groups located at these sites are detected in the¹H MAS spectrum at 3.6 ppm. Further, MAPO-36 catalyzed acetone conversion to mesityloxide that cracked at elevated temperature to yield acetic acid and aliphatics.     

The determinants of heat-shock element-directed lacZ expression in Saccharomyces cerevisiae.

Heat-shock induction of heat-shock protein genes is due to a specific promoter element (the heat-shock element, HSE). This study used lacZ under HSE control (HSE-lacZ) to characterize HSE activity in Saccharomyces cerevisiae cells of different physiological states and differing genetic backgrounds. In batch fermentations HSE-lacZ induction by heat shock was maximal in exponential growth, and showed marked decline with the approach to stationary phase. Expression in the absence of heat shock was unaffected by growth phase, indicating that the growth-dependent expression of many yeast heat-shock genes uses promoter elements in addition to the HSE. Heat-induced expression was strongly influenced by the temperature at which cultures were grown. While basal, uninduced expression was constant during growth at different temperatures to 30 degrees C, induction by transfer to 39 degrees C was reduced by increases in growth temperature as low as 18-24 degrees C. Maximal HSE-lacZ induction (30- to 50-fold) was in cultures grown at low temperatures (18-24 degrees C), then heat shocked at 39 degrees C. Ethanol was a poor inducer. Mutations having little effect on HSE-lacZ expression included a respiratory petite; ubi4 (which inactivates the poly-ubiquitin gene); also ubc4 and ubc5 (which each inactivate one of the ubiquitin ligases involved in degradation of aberrant protein). pep4-3 increased both basal and induced beta-galactosidase about two-fold, probably because of slower turnover of this enzyme in pep4-3 strains.     

双噁唑啉化合物对PBT的增粘作用

以２．２＇－双（２－唑啉）和双（２－唑啉基）苯作扩链剂，用焙融挤出的方法，对聚对苯二甲酸丁二酯（ＰＢＴ）进行扩链，考察扩链剂的用量、反应时间和反应温度对ＰＢＴ的特性粘度及端羧基含量（ＣＶ）的影响。结果表明，当用２，２＇－双（２－唑啉）作扩链剂时，ＰＢＴ的特性粘度［η］从０．７９９提高到０．９２６ｄＬ／ｇ，ＣＶ降至５ｅｑ／１０￣６ｇ以下；当用双（２－　唑啉基）苯作扩链剂，［η］从０．７６３增至０．９２５ｄＬ／ｇ，ＣＶ降至１０ｅｑ／１０￣６ｇ以下，达到了较满意的扩链效果。     

Film morphology and reaction rate for the CVD of tungsten by the WF6—SiH4 reaction

Journal of Electronic Materials - Low pressure chemical vapor deposition (LPCVD) of tungsten (W) by SiH4 reduction of WF6 on Si(100) surfaces was studied in a single-wafer, cold-wall reactor over a...     

VAc／MMA半连续乳液共聚合的研究：Ⅱ分子量及其分布

以过硫酸铵为引发剂，十二烷基硫酸钠为乳化剂，于７０℃下进行了ＶＡｃ／ＭＭＡ乳液共聚合试验。试验确定了不同组成ＶＡｃ／ＭＭＡ共聚物的Ｍａｒｋ－Ｈｏｕｗｉｎｋ方程参数Ｋ和α值。对ＧＰＣ测试数据处理给出了加料速率，乳化剂量，单体比例及种子与非种子法对分子是及其分布的影响。     

不同品位高钛渣对沸腾氯化工艺的影响

分别以94％品位高钛渣和90％品位高钛渣为原料，采用沸腾氯化工艺制备粗TiCl4，分析了两种品位高钛渣对沸腾氯化工艺的影响。结果表明：94％品位高钛渣由于其活性低而对沸腾氯化工艺的影响较大。     

VNS反应合成LLM-116

以1,3-二硝基吡唑为原料,经热重排、氨气中和得到3,5-二硝基吡唑铵盐,然后酸化得到3,5-二硝基吡唑。以三甲基肼碘化物（TMHI）作为异常亲核取代氢（VNS）反应试剂,与3,5-二硝基吡唑在叔丁醇钾为催化剂,利用VNS反应合成4-氨基-3,5-二硝基吡唑（LLM-116）。采用红外分析、核磁共振、元素分析等仪器鉴定了其结构,讨论了VNS反应机理及影响因素。通过实验,得出最佳VNS反应试剂为TMHI,反应时间为4h,反应温度为25℃,收率达到60%。     

Advances in titanium metal injection molding

The approaches to production of titanium powder injection molded parts are reviewed. Historically, oxygen levels have been too high for structural use (particularly with the Ti-6Al-4V alloy). However, recent advances in starting powders, binders and sintering facilities now allow oxygen levels in the Ti-6Al-4V alloy to be controlled to about 0.2 wt.% oxygen. This should result in significant expansion of the titanium PIM market place into aerospace, automobiles, surgical instruments, dentistry, communication devices (such as computers and cell phones), knives and guns. __________ Translated from Poroshkovaya Metallurgiya, Vol. 46, No. 5–6 (455), pp. 118–125, 2007.