影响一步摄影正象色调与银颗粒大小的几个因素

用透射电子显微镜观察一步摄影正片(明胶介质)的银颗粒,对影响银颗粒大小的因素进行了研究。卤化银负片乳剂中的碘含量,明显地影响卤化银颗粒大小和转印后银颗粒的大小,随着卤化银乳剂中的碘含量减少,卤化银颗粒和银质点簇(即银颗粒)变大,组成银质点簇的银质点数目增多,正象色调由棕向黑转移。不同物理显影核亦显著影响正片银颗粒大小与其色调。     

SOME FACTORS AFFECTING THE THERMOCHEMILUMINESCENCE OF CHLOROPHYLL

Abstract— The therrnochemiluminescence of the chloroplasts from normal lettuce seedlings is enhanced by the addition of β carotene but not by chlorophyll a .The thermochemiluminescence of chloroplasts from etiolated seedlings is enhanced by neither β carotene nor chlorophyll a .A variety of electron donors were substituted for β carotene in the mixtures with chlorophyll a .The most active were squalene, β carotene, vitamin A, and nerolidol.
The isoprene structure (-CH₂-CCH₃=CH-CH₂-) appears to be a necessary but not sufficient requirement for energy transfer during thermochemiluminescence.Changes in the absorption spectra indicate that both chlorophyll and carotene are destroyed during thermochemiluminescence.     

THE VISCOELASTICITY AND STABILITY OF CORN OIL-IN-WATER EMULSIONS STABILISED BY WATER SOLUBLE MEAT PROTEINS AND MONO- AND DI-GLYCERIDES

The viscoelastic properties and stability of concentrated corn oil-in-water emulsions stabilised with 2.0% water soluble meat proteins (WSMP) were examined before, and after, partial replacement of WSMP by a blend of mono- and di-glycerides at pH 2.5 - 7.5. Using protein/glycerides mixtures improvements were observed, the level depending on protein/glycerides ratio, mono-/ di-glyceride ratio within the glycerides component, and pH. It is suggested that protein and glycerides associate to form a complex at the critical values of the three variables at which maximum improvement was observed.     

影响重氮片影像颜色的因素

本文探讨了重氮片的主要组份——偶合剂、重氮化合物和成膜剂对重氮片颜色的影响.试验结果说明:不同芳核结构的偶合剂以及在重氮盐中引入不同芳核和取代基对重氮片的影像颜色影响较大,另外,重氮片所用的成膜剂对其影像颜色也有影响.     

EFFECT OF PREMIX CONDITION,SURFACTANT CONCENTRATION,AND OIL LEVEL ON THE FORMATION OF OIL-IN-WATER EMULSIONS BY HOMOGENIZATION

Oil-in-water emulsions were prepared on a homogenizer from good premixes and poor premixes. The quality of the emulsions was determined by measuring the droplet size distribution using spectroturbidimetry. A good premix to the homogenizer produces a better emulsion than a poor premix. Premix conditions become less important when the concentration of emulsifier is increased in relation to the amount of oil. Increasing oil concentration results in a poorer final emulsion. Large amounts of emulsifier negate the advantage of using the homogenizer, but greater mechanical energy input can compensate for reduced emulsifier concentration, a cost saving when formulating an emulsion.     

EFFECT OF CHAIN LENGTH OF OXYETHYLENE GROUP ON PARTICLE SIZE AND ABSORPTION SPECTRA OF SILVER NANOPARTICLES PREPARED IN NON-IONIC WATER-IN-OIL MICRO EMULSIONS

The formation of silver nanoparticles by the method of reduction of silver ions by sodium borohydride in non-ionic water-in-oil microemulsion was investigated as a function of structure of the surfactant. Three types of non-ionic surfactants were selected differing in the chain length of the oxyethylene groups for example: NP-5, NP-9 and NP-11. The silver nanoparticles were characterized by UV-Visible Absorption Spectroscopy and Transmission Electron Microscopy. TEM. The results of this study showed that the panicle size is relatively smaller incase of NP-9 while for NP-5 and NP-11 the sizes are comparable. This obsevation is explained on the basis of structure of the droplets and the influence of Intermicellar exchange on nucleation and growth of particles.     

STABILITY OF WATER-IN-CRUDE OIL EMULSIONS: ROLE PLAYED BY THE STATE OF SOLVATION OF ASPHALTENES AND BY WAXES

The stability of water-in-crude oil (or model crude oil) emulsions was determined by means of separation/sedimentation tests and high voltage destabilization tests. First the impact of the state of solvation of asphaltencs on their ability to stabilize emulsions were studied. Secondly, we analyzed the role of naturally occurring waxes in the stabilization of emulsions. Finally, the emulsion stability when both asphaltenes and waxes are involved was investigated.     

BIOCHEMICAL FACTORS AFFECTING THE QUANTUM EFFICIENCY OF HYDROGEN PRODUCTION BY MEMBRANES OF GREEN PHOTOSYNTHETIC BACTERIA*

Abstract— Photohydrogen production, 200-700 μmol H₂ h^?1 (mg bacteriochlorophyll a)^?1 has been obtained in a system containing unit membrane vesicles (Complex I) from the green photosynthetic bacterium Chiorobium limicola f. thiosulfatophilum, ascorbate, N,N,N′,N′-tetramethyl-p-phenylene-diamine, dithioerythritol, an oxygen scavenging mixture, either methyl viologen (MV) or clostridial ferredoxin (CPS Fd) as electron carrier, and either CPS hydrogenase or platinum asbestos as catalyst. All components are necessary for maximum activity, and spinach Fd cannot be substituted for CPS Fd. Higher rates of photohydrogen production are obtained using MV or CPS Fd with hydrogenase than with MV and Pt asbestos. The highest quantum efficiencies (7–10% at 0.2–0.9 mW absorbed light and over 20% at lower light) were obtained with CPS Fd, hydrogenase and non-saturating 812 nm light. With saturating white light, however, rates of photohydrogen production varied relatively little among the various combinations of electron carrier and catalyst tested. The reaction rate is unaffected by 0.03% Triton X-100, and is insensitive to treatment with antimycin a or m-chloro-carbonyl cyanide phenylhydrazone. This indicates that neither electron flow through an endogenous cyclic chain, nor maintenance of a proton gradient are involved in this process.     

STUDIES ON THE BLEND OF POLYACRYLATE EMULSIONS AND TACKIFIER RESIN EMULSIONS

A series of polyacrylate emulsions were blended with tackifier resin emulsions such asmodified rosin emulsion, C5 resin and C9 resin emulsion. The miscibility of the polyacry-lates and tackifier resins was investigated by means of SEM and visual observation. Thephase diagrams of the miscibility change systematically with the polarity of polyacrylatesand tackifier resins. The influence of the content of the tackifier resins on the adhesionproperties of the polyacrylate emulsions were also studied. The results show that the180℃ peel strength is improved as the amount of the tackifier resin increases and comesto a maximum at a specific content. The ball tack property decreases slightly and the holdstrength changes complicatedly as the tackifier resin increases.     

有机元素分析中影响燃烧过程的因素

燃烧过程是有机元素分析中十分重要而又较难把握的一个步骤。本文介绍了有机元素分析中影响燃烧过程的因素及控制方法。     

旋转粘度计检定中的不确定度来源及影响因素控制

根据旋转粘度计测量粘度的原理及旋转粘度计常数计算公式,分析了旋转粘度计检定中的不确定度来源。提出了旋转粘度计检定过程中影响因素的控制方法。     

一步法密胺树脂的结构和性能

氨基树脂在各种保护涂料中广泛用作交联剂。为了满足高固体分卷板涂料的高技术性能要求,我(?)研制子一步法工艺,并中试(30公斤)成功合成了低聚合度、高反应性丁氧基甲基密胺树脂(BMM-90),采用化学分析方法,GPC和TG、DTG技术表征了其结构和反应性,并进行了卷板涂料漆膜性能评价、     

影响水热合成VPI-5及Si-VPI-5的因素

使用二正丙胺(DPA)和二正丁胺(DBA)作结构导向剂合成出VPI-5和Si-VPI-5,并以二异丙胺(DIPA)为结构导向剂成功地合成出高结晶度的超大孔磷酸铝分子筛VPI-5,其XRD谱图中未检测出其他杂质峰.VPI-5分子筛不同于一般中微孔磷酸铝分子筛,合成条件极其苛刻,为此对原料组成、成胶条件、陈化时间和温度、晶化时间和温度、结构导向剂种类、pH等合成条件对VPI-5分子筛结晶度的影响作了较为详尽的研究,结果表明有机胺在晶化过程中具有结构导向作用,但不起空间填充作用,加有机胺前的陈化过程是必要的.     

有机胺与醌类化合物电荷转移络合物的研究

研究了二异丙胺(DIPA)、2,2,6,6—四甲基—4—羟基啶(TMHP)与四氯苯醌(CA)、苯醌(BQ)在一些溶剂形成电荷转移络合物(CTC)的反应。结果表明:DTPA—CA呈色较快,生成的CTC紫外光谱λ_(CTC)吸收值变化大。在环已烷中分离出N-取代产物。用甲醇作溶剂,则得到2,3,5,6-四甲氧基-1.4-苯醌(TMOBQ)。文中还用电子自旋共振谱,证实了CTC中存在醌负离子自由间体。     

脱乙酰甲壳质和卡拉胶的稀溶液反应

本文研究了脱乙酰甲壳质和卡拉胶为稀溶液时的电离及两者之间的相互作用。卡拉胶在溶液中呈强酸型聚电解质行为,而脱乙酰甲壳质呈弱碱型聚电解质行为并随脱乙酰度提高而碱性下降。脱乙酰甲壳质和卡拉胶的稀溶液反应生成不溶于水的白色沉淀。浊度测量显示,在pH值低于4时,反应是化学计量的,说明这时它们之间的反应主要是通过静电相互作用而形电解质复合物沉淀。当pH值较高时,反应偏离化学计量结果。     

在样模制备法中影响有序金属Ni纳米线尺寸的因素

以多孔氧化铝为样模,运用电沉积法向样模的微孔中沉积金属Ni,制备得到了有序排列的金属Ni纳米线阵列;以透射电镜为主要表征手段,系统地研究了多孔氧化铝样模的制备条件对金属Ni纳米线尺寸的影响;结果表明：制备多孔氧化铝样模过程中的氧化介质、氧化温度、氧化电压以及氧化后的扩孔时间影响Ni纳米线的直径和长度,而电沉金属镍时的沉积电压和沉积时间则主要影响纳米线的长度。     

泡压-滤速法研究聚丙烯微孔膜的孔径及其分布

膜科学与膜技术作为新兴的材料科学分支之一,在国民经济中发挥着越来越重要的作用．近年来,高分子微孔膜的研究与应用正引起人们日益增长的关注．采用双轴拉伸方法制备的聚丙烯微孔膜同时具备了良好的力学性能和透过性能［１］,克服了单轴拉伸方法各向异性的缺点,是一...     

内部增感的核壳乳剂制备及应用

本文制备了一种内部增感的核壳乳剂,其核经增感到一定程度后,表面形成堆积银原子作为空隙陷阱。该乳剂与表敏乳剂混合后,可提高感光度、反差和最大密度,本文研究了内增感乳剂制备过程影响因素,并对混合体系作用机理进行了初步探讨。