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1.
以大孔吸附树脂D3520对豆腐柴叶色素的吸附行为为研究对象,对色素的吸附平衡和吸附动力学进行研究,以Langmuir公式拟合25□下的吸附等温线,结果表明:D3520树脂对色素吸附规律较好的符合Langmuir吸附等温式.  相似文献   

2.
本文研究了吸附树脂D3520负载的氧化钴催化剂对甲酚氧化反应中的催化性能。结果表明:该催化剂具有良好的活性和选择性;甲醇为反应的良溶剂;D3520载体对活性组份具有良好的吸附性能,延长了催化剂的使用寿命。  相似文献   

3.
通过静态吸附实验,研究了聚乙烯吡啶树脂(PVP)对富马酸的吸附性能。结果表明,该树脂对富马酸的吸附等温线同时满足Langmuir和Freundlich等温吸附方程;在无机盐存在下,与大孔强碱性树脂D204、弱碱树脂D308相比,PVP吸附富马酸的性能几乎不受无机盐的影响。D204树脂吸附富马酸是离子交换作用,D308树脂通过Lewis作用和静电作用吸附富马酸,而PVP树脂对富马酸的吸附行为是氢键所致,吸附为放热过程且能够自发进行。  相似文献   

4.
牛磺酸在大孔吸附树脂上的吸附-解吸行为研究   总被引:4,自引:0,他引:4  
本文研究了S-8、D4020、NKA2、AB-8、D4006、NKA9、D3520、X-5等国产树脂对牛磺酸的吸附行为.S-8和D4020对牛磺酸的吸附能力较强,静态吸附容量在12mg/g以上.实验测定了28℃时牛磺酸在S-8和D4020上的吸附等温线,并研究了pH、盐析效应和温度对牛磺酸在S-8和D4020上吸附的影响,结果表明,温度对吸附影响很大.用80℃去离子水对吸附在树脂上的牛磺酸进行解吸,解吸率可达90%以上.  相似文献   

5.
乐薇 《化学研究与应用》2011,23(9):1264-1268
以静态和动态两种方式研究了D101大孔树脂对血竭总黄酮的吸附情况,对静态吸附曲线和动态穿透曲线进行了数学拟合,并计算了静态吸附的热力学参数,结果表明:(1)D101树脂对血竭总黄酮的吸附等温线能用Langmuir方程和Freundlich方程较好的拟合,外加KCi或NaCl能提高D101树脂对血竭总黄酮的吸附容量;(2...  相似文献   

6.
研究考察了β-萘磺酸(NSA)和硫酸在弱碱性D301R树脂上的单组分、双组分吸附行为。研究表明,硫酸在D301R树脂上的吸附容量远大于NSA。分别采用Langmuir和Freundlich模型对单组分试验数据进行了拟合。以多组分吸附IAST模型和Langmuir、Freundlich模型预测了硫酸、NSA在弱碱性D301R树脂上竞争吸附相平衡,模型与试验结果吻合的较好,该模型可较准确地预测双组分的竞争吸附行为。  相似文献   

7.
Pd—Sn/吸附树脂催化剂上对硝基氯苯选择加氢的研究   总被引:3,自引:0,他引:3  
本文研究了大孔聚苯乙烯系吸附树脂D3520负载的钯-锡催化剂氢化对硝基氯苯的性能及动力学,并对催化剂作了表征。SnO引入有良好的助催化作用。Pd/Sn原子比为0.8时,催化活性较Pd/D3520高50%,选择性为95%,较Pd/D3520提高21.6%。可认为反应速度对底物浓度有一极大值,可能为L-H机理。反应为双分子吸附的表面反应。  相似文献   

8.
黄姜黄色素在大孔树脂上的吸附动力学研究   总被引:3,自引:0,他引:3  
采用静态法考察了8种大孔吸附树脂对黄姜黄色素的吸附及解吸特性,筛选出LX-18G树脂具有较高的吸附选择性和良好的脱附性能.以LX-18G树脂对黄姜色素的吸附平衡和吸附动力学进行了深入探讨,测定了不同温度下黄姜色素在该树脂上的吸附等温线,以及不同温度,初始液浓度和转速下的吸附动力学曲线.结果表明,Langmuir方程可更好地描述黄姜色素在该树脂上的吸附平衡.吸附动力学规律可用二级速率方程表示,液膜扩散和颗粒内扩散分别是吸附初期和吸附后期的主要速率控制步骤,吸附活化能为5.37kJ/mol.  相似文献   

9.
考察了6种不同树脂对豆腐柴果胶提取液的脱色作用.详细地研究了吸附工艺条件对树脂脱色能力的影响.试验结果表明,在pH为2.0和温度为25℃下,以0.34BV/min流速进行吸附时,D3520树脂对豆腐柴果胶提取液具有良好的脱色效果;并对树脂再生的条件进行了较详细的研究.  相似文献   

10.
大孔吸附树脂分离纯化荔枝核黄酮类化合物的研究   总被引:6,自引:2,他引:6  
比较了D101、D3520、NKAII、AB-8、X-5、HPD-100、HPD-300、HPD-600等8种大孔吸附树脂对荔枝核中抗乙肝活性成分黄酮类化合物的吸附及解吸性能,筛选出效果较好的HPD-300树脂进行分离纯化实验研究。实验表明,HPD-300树脂能够有效地吸附和解吸荔枝核黄酮类化合物,并确定了最佳的吸附和解吸工艺参数。采用最佳的工艺条件分离纯化荔枝核黄酮类化合物,黄酮类化合物的含量由31%提高到82%。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

14.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

15.
Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.  相似文献   

16.
17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

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19.
The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

20.
Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.  相似文献   

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