双波长标准加入法同时测定合金钢中钼和钨

在金属离子显色体系中,采用双波长分光光度法同时测定了合金钢中的钼和钨。对显色反应和光度测定的最佳条件进行了详细考察。在介质盐酸浓度为０．６～１．２ｍｏｌ／Ｌ,ＳＡＦ质量浓度为２０～６０ｍｇ／Ｌ,ＣＴＭＡＢ质量浓度为０．１８～０．４２ｇ／Ｌ的显色体系中,能够形成Ｗ－ＳＡＦ－ＣＴＭＡＢ和Ｍｏ－ＳＡＦ－ＣＴＭＡＢ络合物,吸光度值高且稳定。根据两络合物的吸收光谱,选择钼作为标准加入组分,在钨的等吸收点波长     

联苯胺-H_2O_2-HRP伏安酶联免疫分析体系测定植物病毒TMV和TRSV

提出了联苯胺－Ｈ２Ｏ２－辣根过氧化物酶（ＨＲＰ）伏安酶联免疫分析体系测定植物病毒烟草花叶病毒（ＴＭＶ）和烟草环斑病毒（ＴＲＳＶ）的新方法。ＨＲＰ标记的羊抗兔酶标记抗体ＩｇＧ－ＨＲＰ可以催化Ｈ２Ｏ２氧化联苯胺的反应,其氧化产物在Ｂｒｉｔｏｎ－Ｒｏｂｉｎｓｏｎ（ＢＲ）缓冲溶液中在－０．６２Ｖ（ＳＣＥ）左右产生灵敏的线性扫描二阶导数伏安峰,可以测定ＩｇＧ－ＨＲＰ。根据ＩｇＧ－ＨＲＰ与植物病毒及其抗血清的免疫反应,可以间接测定植物病毒。本法测定ＴＭＶ的检出限为０．２５ｎｇ／ｍＬ,线性范围为０．２５～５０００ｎｇ／ｍＬ;测定ＴＲＳＶ的检出限为１．５ｎｇ／ｍＬ,线性范围为１．５～３０００ｎｇ／ｍＬ;测定ＴＭＶ烟草病叶澄清液的最高稀释比为１∶１００００。检测灵敏度高于酶联免疫吸附显色光度法（ＥＬＩＳＡ）     

在蒸气相中合成中孔分子筛MCM—41及其孔结构参数的表征

在水蒸气中，由含表面活性剂十六烷基三甲基溴化铵的无定形凝胶合成出Ｓｉ－ＭＣＭ－４１和Ａｌ－Ｓｉ－ＭＣＭ－４１分子筛纯相，研究了它们的合成条件。     

Cu—M／ZSM—S（M=Ce,La,Ag）催化剂的表征及其对NO直接分解催化活性？…

考察了用分散法制备的Ｃｕ－Ｍ／ＺＳＭ－５（Ｍ＝Ｃｅ,Ｌａ,Ａｇ）催化剂对ＮＯ直接分解的催化活性,并且用ＸＲＤ、ＳＥＭ、ＴＰＲ、ＸＰＳ及ＩＣＡＰ等手段对催化剂进行了表征。结果表明添加Ｃｅ有利于增加催化剂的铜离子交换度,添加Ａｇ有可能使ＺＳＭ－５分子筛的骨架结构发生改变,从而对催化剂活性产生影响。     

部分水解法制备高分子量水溶性（丙烯酰胺／丙烯酸／2—丙烯酰胺—2—？…

系列的谪分子量水溶性丙烯酰胺／丙烯酸／２－丙烯酰胺－２－甲基丙磺酸（ＡＭ／ＡＡ／ＡＭＰＳ）三元共聚物（Ｐ３Ａ）由相应的（ＡＭ／ＡＭＰＳ０二元共聚物通过部分水解方法制得。聚合物的结构和组成使用电位滴定和＾１３Ｃ－ＮＭＲ谱测定,得到的结果指出,在设定的试验条件下,水解过程中,高分子链上ＡＭＰＳ单元具有充分的稳定性,而丙烯酰胺基平稳地转变为丙烯酸。在所有不同聚合物（Ｐ２Ａ）情况下,由于阴离子基团的ＯＨ＾     

小晶粒Fe—ZSM—5分子筛的合成及其催化性能的研究

采用水热合成法,合成出小晶粒的Ｆｅ－ＺＳＭ－５分子筛。分别用Ｘ射线粉末衍射技术测定其物相,ＳＥＭ及粒度分析（ＳＤＰ）测定了晶粒的大小,并考察了它在ＭＴＧ反应中的催化性能。结果表明：合成出的小晶粒Ｆｅ－ＺＳＭ－５分子筛平均只有０４～０６μｍ,并且粒度分布均匀,有较大的比表面,在ＭＴＧ反应中表现出优异的催化性能     

植物油的质谱分析：1.蓖麻油

运用一种植物油的系统分析方法测定蓖麻油的精细组分，这包括皂化，ＢＦ３－ＭｅＯＨ甲基化，ＧＣ－ＣＩＭＳ法测定脂肪酸碳链长度和不饱和度，ＡＭＰ衍生化，ＧＣ－ＥＩＭＳ测定不饱和脂肪酸的双链位置，分析了蓖麻油的十一种脂肪酸组分，有五个为未知组分，并测定了其中三个组分的双链位置。     

等离子体原子发射光谱/质谱在新型陶瓷材料分析中的应用

本文对近几年来等离子体原子发射光谱（ＩＣＰ－ＡＥＳ）和等离子体质谱（ＩＣＰ－ＭＳ）在新型陶瓷材料分析中的应用进行了评述,讨论了应用ＩＣＰ－ＡＥＳ／ＭＳ技术测定陶瓷材料中痕量杂质的各种进样技术。引用文献６０篇。     

溶剂化金属原子浸渍法制备的Ni-Ag/γ-Al2O3催化剂的结构表征

应用溶剂化金属原子浸渍法和普通浸渍法制备了三种不同摩尔比的γ－Ａｌ２Ｏ３负载Ｎｉ－Ａｇ双金属催化剂。ＸＲＤ和磁测定结果表明ＳＭＡＩ催化剂中Ｎｉ和Ａｇ的粒度均小于金属相同的ＣＩ催化剂。ＳＭＡＩ催化剂中Ｎｉ和Ａｇ未形成合金，而ＣＩ催化剂中Ｎｉ和Ａｇ形成了合金。     

氢化物发生—冷阱捕获—色谱分离—原子吸收法测定天然水中坤的形态

研究建立了氢化物发生－冷阱捕获－色谱分离－原子吸收方法测定天然水中四种主要砷形态，测试系统自行组装，色谱柱填料采用ＣｈｒｏｍｏｓｏｒｂＧＡＷ－ＤＭＣＳ（粒径０．３～０．４５ｍｍ），其上涂布３％ＯＶ－１０１。方法的检出限以砷计分别为：Ａｓ（Ｖ）０．５１ｎｇ，Ａｓ（Ⅲ）０．４３ｎｇ，ＭＭＡ０．３８ｎｇ，ＤＭＡ０．６７ｎｇ；１２ｎｇ砷标准偏差为Ａｓ（Ⅴ）４．２１％，Ａｓ（Ⅱ）３．５６％，ＭＭＡ３．２３％     

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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.