山楂汁中总酸和黄酮在D941树脂上的吸附动力学和热力学

研究了大孔弱碱性阴离子交换树脂D941对山楂汁中总酸和黄酮的静态吸附动力学和热力学特性。动力学研究表明,树脂吸附量与吸附时间呈现对数关系,温度在25℃时吸附均符合拟二级动力学方程。速度控制步骤的研究表明,树脂对山楂汁中总酸的离子交换过程同时受到粒扩散和膜扩散控制,对山楂汁中黄酮的吸附过程受粒扩散控制。热力学研究表明,在温度低于70℃时升高温度有利于树脂对山楂汁中总酸的离子交换和黄酮的吸附;在70~90℃之间,山楂汁中黄酮的吸附量随温度的升高有波动。     

离子交换法从发酵液中提取聚苹果酸

用离子交换法提取发酵液中的聚苹果酸,比较了不同型号的阴离子树脂对聚苹果酸的静态吸附量,其中以D296树脂对聚苹果酸的吸附量最大.通过静态和动态方法,考察了不同操作条件对固定床分离工艺的影响.结果表明,发酵液经预处理后,调pH至9.5,以lBV/h流速上柱吸附,上柱量为4BV;用0.5mol/L NaCl洗脱,速度为1BV/h.该工艺能够将发酵液中大部分杂质去除,PMLA样品的纯度达到 93.2%,提取收率为79.46%.     

国产732型阳离子交换树脂吸附L-精氨酸的特性

考察了溶液中氯化钠和氯化铵浓度、pH值、温度对732阳离子交换树脂吸附L－精氨酸的影响规律。结果表明：随着无机盐浓度的增大L－精氨酸的吸附率急剧降低，且盐浓度在大于1.0mol/L时几乎无法吸附；在低于等电点下，随着pH值的下降L－精氨酸的吸附率增大；适当升高温度，有助于提高L－精氨酸的吸附率。     

超高交联树脂对苯胺的吸附机理研究

在静态条件下，研究了水溶液中超高交联树脂AM－1和NJ－8及大孔吸附树脂Amberlite XAD－4吸附苯胺的热力学特性，测定了不同温度下的吸附等温线。结果表明，在稀溶液中3种树脂吸附苯胺都符合Langmuir和Freundlich模型，其中AM－1和NJ－8对苯胺的吸附是一个吸热过程；由于AM－1和NJ－8的微孔结构和表面存在酸性基团的吸附中心，对苯胺的吸附是物理吸附和化学吸附共同作用的结果。     

大孔网状树脂对三丁基氯化锡的吸附特性研究

从热力学，动力学及柱上吸附三方面讨论了Ｘ－５大网树脂对三丁基氯化锡的吸附特性。结果表明，吸附剂的吸附过程以物理吸附为主，外表面，内表面的吸附率分别为３８％，６２％装柱动态吸附率主要取决于柱长及流速，而溶液盐度及ｐＨ值影响不大。     

ND-100超高交联吸附树脂对水中苯酚的吸附行为研究

通过静态吸附试验，研究了ND－100超高交联树脂对水溶液中苯酚的吸附动力学和热力学特性，探讨了初始浓度对吸附过程的影响。结果表明 ND－100树脂对苯酚的吸附速率同时受液膜扩散和颗粒内扩散过程控制。吸附符合Langmuir和Freundlich等温吸附方程，吸附量随着温度的升高而降低，随着平衡浓度的增大而增大，吸附表现为放热的物理吸附过程。     

凝胶型交联聚苯乙烯—异氰尿酸树酯对酚类物质的吸附机理研究

由氯甲基化低交联聚苯乙烯和异氰尿酸在三乙胺作用下反应,制得了凝胶型交联聚苯乙烯－异氰尿酸树脂,测定了该树脂对苯酚和间苯二酚在不同温度下的吸附等温线,依据Clapeyron0Clausius方程从吸附等温线计算出了吸附热,从热力学的角度论证了树脂是基于氢键键合的疏水作用而吸附苯酚和间苯二酚的。     

N_（1923）萃淋树脂对钯吸萃性能及机理的研究

Ｎ＿（１９２３）萃淋树脂是胺类萃淋树脂。本文报道了该树脂在酸性体系中对钯的静态分配比。讨论了温度、树脂用量，振摇时间对吸附钯的影响。确定了吸萃物的组成比，并用红外光谱探讨了树脂吸附钯的机理。在此基础上，进行树脂的柱色层试验，结果表明此树脂为萃取色层的新固定相，树脂上吸附的钯可用０．０５０ｍｏｌ／Ｌ硫脲－０．５０ｍｏｌ／ＬＨＣｌ溶液解脱，树脂可再生和重复使用。     

牛磺酸在大孔吸附树脂上的吸附-解吸行为研究

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．     

牛磺酸在大孔吸附树脂上的吸附—解吸附行为研究

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,静态吸附容量为１２ｍｇ／ｇ以上。实验测定了２８℃时牛磺酸在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。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.