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1.
Thermodynamic parameters have been determined for the interaction of methyl orange and poly(vinylpyrrolidone) in aqueous solutions containing tris, tris and hydrochloric acid, or water only. Enthalpy changes were determined by use of a flow microcalorimeter. Free energy changes were calculated from the results of equilbrium dialysis studies. The results are interpreted in terms of the behaviour of poly(vinylpyrrolidone) in these systems. Analysis of data shows that the hydrophobic interactions in the systems are in the order: tris > wateronly > tris-HC1.  相似文献   
2.
应用微热量热仪测定了斯蒂芬酸(TNR)在溶剂N,N-二甲基甲酰胺(DMF)中不同浓度(b)时的溶解焓,用计算机拟合的方法求得计算该物质溶解焓(ΔsolH)的经验公式(ΔsolH=-14.392-988.6b 34.992b1/2)。由此得到了该物质的标准摩尔溶解焓(ΔsolHmθ=-14.392 kJ.mol-1),并分别推导出了TNR的相对表观摩尔焓、相对偏摩尔焓以及配合物的稀释焓的经验公式。同时,对TNR溶液反应的动力学进行了研究,通过分析热流对时间的曲线图,确定了该溶解反应的速率常数为1.632×10-3s-1,反应级数为0.6158。  相似文献   
3.
张蕊 《山东化工》2006,35(4):26-28
利用微量量热法测定了一种水溶性高分子NCP与表面活性剂SDS(十二烷基硫酸钠)、原油、油砂的热效应,实验结果表明NCP与SDS、原油、油砂存在明显的热效应,说明它们问存在以静电力为主的超分子化学作用,并通过实验测定了在驱油过程中应该控制的浓度范围,为实际驱油提供了一定参考。  相似文献   
4.
根据制备过程,提出了配合物Cu(TO)2Cl2在混合溶液中的晶体生长的动力学模型。通过这个动力学模型,测定了一系列的动力学参数Ea=45.37kJ·mol-1,ln(A/s-1)=14.65,Δ≠Gm=82.11kJ·mol-1,Δ≠Hm=42.85kJ·mol-1,Δ≠Sm=131.58J·mol-1·K-1。另外,用RD496-Ⅲ型微量热计测定了该化合物在298.15K时的比热容,并计算了[Cu(TO)2]2 (aq)和Cu(TO)2Cl2(s)的标准生成焓。  相似文献   
5.
A new method is introduced to study the action between biomaterials and organism. By using an LKB- 2277 bioactivity monitor and ampoule method, the fundamental thermogenesis curves of the metabolic process of pk-15 and the toxic effect of three kinds of selenomorpholine compounds on it were studied at 37℃. From the thermogenesis curves, the heat released by pk-15 metabolism was calculated. The results show that the selenium compounds all have toxic action on the metabolism process of pk-15 at the range of experimental concentrations. The sequence of the toxic action of selenium compounds is: Na2SeO3>β- ( N- selenomorpholine) -ethyl phenyike-tone hydrochloride > selenomorpholine.  相似文献   
6.
1 IntroductionChemicalssuchasheavymetalsandorganiccom poundspossiblehaveeffectsontheenvironmentandthreatstohumanhealth .However,agriculture ,industry ,andmedicinerelyontheuseofpreciselythesechemicals .Practicalresolutionoftheseconflictinginterestsrequires…  相似文献   
7.
The combination of thermogravimetry, microcalorimetry and infrared spectroscopy studies of pyridine adsorption has been used to characterize the acidity of a ZSM-5 catalyst. The majority of the acid sites are Brønsted acid centers associated with framework Al species, with heats of pyridine adsorption equal to 140 kJ/mol. Non-framework Al species in the zeolite sample of this study eliminate an approximately equal number of Brønsted acid sites. These nonframework Al species also produce strong Lewis acid sites with pyridine adsorption heats greater than 140 kJ/mol, as well as weak adsorption sites (e.g., weak Bransted acid sites or hydrogen bonding sites) with heats equal to 90–140 kJ/mol.  相似文献   
8.
微量热法研究砷对大肠杆菌的作用   总被引:1,自引:0,他引:1  
采用瑞典产LKB-2277生物活性检测系统(热导式微量热计),用停流法研究了NaAsO2和Na3AsO4对大肠杆菌作用的热功率输出曲线,得到了大肠杆菌在不同药物浓度下的生长速率常数k、半抑制浓度IC50等参数,定量说明了砷对大肠杆菌有很强的抑制作用,且NaAsO2的毒性比Na3AsO4的毒性强。结果表明微量热法用于研究药物与生物体的相互作用具有独到之处。  相似文献   
9.
An extensive investigation of the influence of aliphatic alcohols on the metabolic activity of a heterogeneous culture has been carried out using flow microcalorimetry as a monitoring technique. The response of the culture to the addition of alcohols (n-C3 to n-C8, t-C4) has been examined for the microorganisms under endogenous conditions and substrate saturation conditions, and IC50 values were determined for each state. For the n-alcohols, the inhibitory behavior was further examined through systematic variations of substrate and alcohol concentrations; the results yield inhibition patterns which show specific behavior both as function of alcohol concentration and alcohol chain length. Generally, the toxicity results obtained with the heterogeneous culture follow rather closely those found in homogeneous cultures. However, the initial effect of alcohols at low concentration show marked variations among various types of culture or when compared to other reference systems.  相似文献   
10.
Starches isolated from wheat (Rapoport's variety) at different stages of maturation and from completely maturated rye (Viatka‐2 variety) were investigated in excess of water and in 0.6 M KCl using high sensitivity differential scanning microcalorimetry (HSDSC). Applying some physico‐chemical approaches, the starch polymorphous structure, the thickness of the crystalline lamellae and the thermodynamic parameters characterizing their surface faces were determined. It has been established that wheat and rye starches belong to the A‐type starches. It is suggested that during biosynthesis of granules the formation of the A‐type structure is accompanied by an accumulation of crystal defects. This process leads to a decrease in the melting temperature of starches.  相似文献   
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