高放废液中分离回收镧系-锕系元素萃取剂的研究进展

概述了近十几年来国内外有关用于高放废液镧系-锕系元素萃取分离中新萃取剂的研究进展,并对酰胺类、硫代磷类、硫代吡唑啉酮类等新萃取剂的设计筛选等进行了讨论。     

酰胺类萃取剂萃取分离铕的研究进展

酰胺类萃取剂容易合成,热稳定性好,能完全燃烧,对环境友好等一系列优点,已广泛的用来从核燃料的后循环中萃取分离镧系元素和锕系元素。论述了使用不同类型的酰胺类萃取剂萃取及其分离铕的研究,重点讨论了丙二酰胺类和丁二酰胺萃取剂、酰胺莢醚类萃取剂、吡啶二甲酰胺类萃取剂、乙酰胺基胺类萃取剂萃取分离铕的最新研究成果,同时对这几类催化剂萃取铕的萃取效果进行了比较和讨论。     

纸上反相分配色谱中铀的协同萃取效应

溶剂萃取中采用混合萃取剂所产生的协同效应,已获得了广泛的研究.特别是以螯合萃取剂与中性萃取剂组成的协同萃取体系,更引起人们的重视.Cvjeticanin将纸上反相分配色谱用于协萃效应的研究.选用螯合萃取剂噻吩甲酰三氟丙酮(TTA)与中性磷类萃取剂磷酸三丁酯(TBP)、三辛基氧化膦(TOPO)或磷酸三辛酯(TOP)组成的混合萃取剂作固定相,研究了对铀、钍和稀土元素的协萃效应,并探讨了有关的协萃机理.     

用于水中矿物油测定的新型萃取剂

探讨了用于水中矿物油测定的新型萃取剂的筛选和超纯新型萃取剂的制备方法,对选定的新型萃取剂与目前我国常用萃取剂的萃取能力进行了较详细的对比研究.     

N,N,N'''',N''''-四丁基丙二酰胺萃取Yb(Ⅲ)的研究

取代酰胺类萃取剂易合成、分解产物易除去可用于萃取铀(Ⅳ)、钍(Ⅳ)，但对高放废液中共存稀土元素的萃取研究较少。本文在以前研究工作的基础上，进一步探讨了TBMA萃取Yb(Ⅲ)的性能。     

N-530萃取铜的动力学协萃研究

一、前言自从羟肟类螯合型萃取剂应用于大规模工业生产以来,萃取动力学的研究受到了很大的重视,成为当前萃取化学中的一个新的较为活跃的领域。由于这类萃取剂萃取铜的速度较慢,开展萃取动力学的研究,搞清萃取反应的机理,从而采取有效的措施,(如添加动力学协萃剂,     

离子交换净化辐照三烷基氧化膦中脂肪酸

本文研究了用大孔阴离子交换树脂D301R从乏萃取剂30%TRPO-煤油溶液中净化去除脂肪酸的方法,探讨了该法用于乏萃取剂净化的可行性。     

泡腾辅助微萃取技术的开发与应用研究进展

泡腾辅助微萃取(EAM)技术是一种利用CO₂供体和H⁺供体反应产生CO₂气泡促进萃取剂快速分散、增大与目标物的接触面积，以实现高效萃取的新型样品预处理手段。该技术具有分散速率快、萃取效率高、使用成本低、应用范围广等优点。得益于萃取剂的快速发展，泡腾辅助微萃取方法的构建和应用范围研究日趋完善和多样，已广泛用于环境、食品、生物等样品的前处理领域。该前处理技术结合各类检测仪器构建新型快速的检测方法，成功实现了重金属离子、农药、内分泌干扰物、抗生素等污染物的检测。在EAM技术的构建中，常考查泡腾片剂的组成、溶液pH、萃取温度、萃取剂种类、萃取剂添加量、洗脱剂种类、洗脱剂体积、洗脱时间、循环使用次数等因素对方法的影响，重点依据线性范围、相关系数、富集因子、检出限、定量限等参数对方法进行评判，最后结合各类仪器检测方法，实现在实际样品检测中的应用。该文从EAM技术常用的萃取剂方面入手，综述了基于纳米材料、离子液体等新兴萃取剂的EAM方法的构建，以及与液相色谱、气相色谱、原子吸收光谱或质谱等大型仪器联用，用于复杂基质中有害物质检测的研究...     

烷基膦酸类萃取剂与喹啉类萃取剂N601协萃锗（Ⅳ）的琛

研究了盐析剂浓度和水相ＰＨ值对分配比Ｄ的影响。研究了烷基膦酸萃取剂Ｐ５０７和喹吉林 类萃取剂Ｎ６０１协萃锗的机理，并对萃取平衡常数和热效应进行了估算。     

烷基膦酸类萃取剂与喹啉类萃取剂N_(601)协萃锗(Ⅳ)的研究

研究了盐析剂浓度和水相ｐＨ值对分配比Ｄ的影响。研究了烷基膦酸萃取剂Ｐ５０７和喹啉类萃取剂Ｎ６０１协萃锗的机理，并对萃取平衡常数和热效应进行了估算。     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.