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1.
Organomineral composite sorbents KU-2×8-ZnS and KU-2×8-PbS were synthesized on the basis of the matrix of a strongly acidic KU-2×8 cation exchanger. Scanning electron microscopy and elemental analysis were used to study their microstructure and chemical composition. With the use of potentiometric titration, their bifunctional nature was revealed and the dissociation constants and the total exchange capacities of the ionogenic groups were determined. The sorption of copper(II), zinc, and cadmium by KU-2×8-ZnS and KU-2×8-PbS sorbents from 0.005 M solutions of their salts was examined. The total dynamic sorption capacity of the composite sorbents for the above metals, found in the study, exceeds similar values for the individual KU-2×8 cation exchanger by a factor of 1.6–2.0 and that in 0.001–0.050 M solutions of potassium and calcium chlorides, by a factor of 1.3–4.5. An explanation is suggested for the sorption process of heavy nonferrous metals on composite sorbents with an active sulfide component by the mechanism of coordination copolymerization.  相似文献   

2.
The title compound Ru(9)Zn(7)Sb(8) was synthesized via a high-temperature reaction from the elements in a stoichiometric ratio, and its structure was solved by a single-crystal X-ray diffraction method. The structure [cubic, space group Fm3m, Pearson symbol cF96, a = 11.9062(14) ? (293 K), and Z = 4] adopts a unique 2a(hh) × 2a(hh) × 2a(hh) supercell of a normal half-Heusler phase and shows abnormal features of atomic coordination against the Pauling rule. The formation of this superstructure was discussed in light of the valence electron concentration per unit cell. It is a metallic conductor [ρ(300 K) = 16 μΩ·m], and differential scanning calorimetry revealed that Ru(9)Zn(7)Sb(8) undergoes a transformation at 1356(1) K and melts, by all indications, congruently at 1386 K. At room temperature, its thermal conductivity is about 3 W/m·K, which is only one-quarter of that of most normal half-Heusler phases. Ru(9)Zn(7)Sb(8) as well as its analogues of iron-, cobalt-, rhodium-, and iridium-containing compounds are expected to serve as a new structure type for exploring new thermoelectric materials.  相似文献   

3.
The separation of metallic impurities from uranium by anion exchange with a Dowex 1×8 resin has been investigated. The following elements can be quantitatively separated from 400 mg uranium using a 1 cm diameter 15 or 30 cm long column. The elements Ag, Al, Ba, Ca, Cr, Cs, K, Mg, Mn, Na, Ni, Rb, REE, Sc, Th, Ti and Y can be separated by eluting the elements with conc. HCl. Uranium is retained by the resin. Al, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Na, REE and V can be separated by eluting with 0.01 N H2SO4. Uranium is retained by the resin. Cd and Zn can be separated by first eluting uranium with 0.5 N HCl and then eluting Cd and Zn with 1 N NH3. Hf, Zr and V can be separated by eluting with 5 N HCl but some uranium contamination is unavoidable.  相似文献   

4.
3-Chloro-N-(8′-quinolyl)benzo[b]thiophene-2-carboxamide was synthesized from 3-chlorobenzo[b] thiophene -2-carboxyl chloride and 8-aminoquinoline in the presence of triethylamine. The single crystal X-ray structure determination confirmed the earlier proposed structure and also characterized by 1HNMR, and Mass spectroscopy. Crystallographic study reveals that the structure crystallizes in monoclinic system, a = 14.878(4) ?, b = 8.4292(15) ?, c = 25.461(7) ?, β = 112.022(18)°, Z = 8, V = 2960.20(12) ?3 with space group C2/c (No. 15). In the structure packing, three kinds of interactions are responsible for the stability of the structure. Infinite two-dimensional stair-like layered chains are formed by relatively strong intermolecular hydrogen bonds [C14—H14...O1]. These parallel chains are connected by several π—π and CH—π interactions, alternatively. There are two such parallel chains with 70.53°, which are in contact by van der Waals interactions.  相似文献   

5.
Ha J  Seo D  Shin D 《Talanta》2011,85(1):252-258
Trans fatty acids (TFAs) are present in meat and dairy products as m ruminant animals and in vegetable fats due to partial hydrogenation. This study aimed to discriminate between natural (N-TFA) and hydrogenated trans fatty (H-TFA) acids by GC × GC-flame ionization detection (GC × GC-FID) and comprehensive GC × GC-time-of-flight mass spectrometry (GC × GC-TOFMS). The separation of two kinds of trans fats, vaccenic acid (18:1 trans-11) and elaidic acid (18:1 trans-9), was performed using GC × GC-FID and GC × GC-TOFMS. A 100 m × 0.25 mm I.D. × 0.2 μm (film thickness) SP-2560 (bis-cyanopropyl polysiloxane) fused capillary column (first separation dimension, 1D) was coupled to a 1.5 m × 0.18 mm I.D. × 0.18 μm (film thickness) RTX-5 (5% diphenyl/95% dimethyl polysiloxane) fused capillary column (second separation dimension, 2D). The RSD of the intra-day repeatability by both GC × GC-FID and GC × GC-TOFMS for elaidic and vaccenic acids was ≤9.56% and ≤9.97%, and the RSD of the inter-day repeatability was ≤8.49 and ≤9.06%, respectively. It was found that the V/E value (vaccenic acid to elaidic acid ratio) could be used to distinguish H-TFA from N-TFA and to evaluate the quality of the fatty foods.  相似文献   

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本文用共聚物小球(以下简称白球)力学性能的快速自动测定方法成功地测定了001×7树脂的表观压缩模量、模量的温度依赖性以及应力松驰性能,以更科学的方法表征了树脂的力学行为。  相似文献   

9.
8,8"-Biflavonoidsareantw0rtantclass0fbiflavonoids.Asasystematicresearchofthe8,8"-biflav0noids,wehavepreviouslyreportedthestudyonthereactionof2'-hydroxychaloneswithl2-H2SO4-DMSOsystem.'InthispaPer,thesynthesisof5,5",7,7',-tetTameth0xy-8,8"-biflavonela2,4,4",7,7"-tetramethoxy-8,8"-biflavone1b',4',4",,5,5,',7,7"-hexamethoxy-8,8"-biflav0ne1c4and4,4"-dibenZyl0xy-5,5",7,7"-tetramothoxy-8,8"-biflavoneldisreported.ThesyntheticmethodisshownintheSchemebelow.2-Hydroxyacet0phenonescondensedwithsubsti…  相似文献   

10.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.  相似文献   

11.
以2-甲氧基酚,丁二酰氯和L-乳酸乙酯为起始原料,用会聚法完成了8’,8”-去甲基三白脂素-8的全合成,总产率1.79%。其结构经1HNMR和MS表征。  相似文献   

12.
以2-甲氧基酚,丁二酰氯和L-乳酸乙酯为起始原料,用会聚法完成了8',8"-去甲基三白脂素-8的全合成,总产率1.79%.其结构经1H NMR和MS表征.  相似文献   

13.
Ti8C12H8簇的理论研究   总被引:1,自引:0,他引:1  
用量子化学从头计算方法, 预测了Ti8C12H8簇的几何结构、电子结构, 分析讨论了该簇的成键和化学反应性质。  相似文献   

14.
结合改进的重叠模型Xa-SW法和Ziegler过渡态法,通过将中心原子与配体的作用选成离子聚集、中心原子只有s和p轨道参与成键、中心原子只有d轨道参与成键、中心原子只有f轨道参与成键、中心原子的s、p、d和f轨道同时参与成键5种类型,从能量角度分析了Ce(C_8H_8)_2和Ce(C_8H_8)~-_2的化学键性质。  相似文献   

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16.
The dynamics of sorption of pure imino acids (proline and hydroxyproline) and imino acids in the presence of aromatic amino acid, phenylalanine, on KU-2 × 8 sulfocation exchanger in the H form was studied. Mutual influence of amino acids on the dynamic characteristics of sorption was observed. This influence changed the shape of elution curves and decreased the working exchange capacity. Both competitive and synergistic sorption mechanisms governed sorption of amino acids from binary solutions.  相似文献   

17.
A chain-like zincophosphate [Zn8(HPO4)8(H2PO4)8]•[(C2H8N)8]•4H2O was obtained at room temperature from a ZnO/P2O5/dimethylamine/H2O mixture. The crystal structure was determined by single crystal X-ray diffraction. The symmetry is monoclinic a=1.26450(7)nm, b=1.08477(5)nm, c=1.46311(4)nm, β=98.793(5)°, space group Cc. The structure consists of chains of zinc-corner-sharing Zn2P2O4 four rings. The negative charge of the chains is compensated by the protonated dimethylamine. The characterization by 31P solid state nmr spectroscopy is also reported.  相似文献   

18.
The ground-state electronic structure of the cyanido complex [U(??8-C8H8)2(CN)]? as well as the thermodynamic properties and infrared spectrum are investigated using density functional theory including scalar relativistic effects. The complex is compared with the well-known uranocene U(??8-C8H8)2. Despite the broken symmetry, the gain in electrostatic interaction and a significant uranium-CN? orbital interaction is sufficient to stabilize the bent CN? complex with respect to uranocene. The formation of the CN? complex is exothermic justifying the recently experimentally reported compound.  相似文献   

19.
This work presents a relativistic calculation of electron delocalization, optical properties, and zero field splitting in a group of molecules with the structure (C(8)H(8))M(μ(2)-,η(8)═C(8)H(8))M(C(8)H(8)), where M = Ti, Zr and Th. Additionally we also studied the heterobimetallic combinations (Ti-Th and Zr-Th). The molecular properties are discussed based on their electronic structure and the influence of the electron mobility in metal-metal communication. Nucleus independent chemical shift (NICS) was determined via the gauge-including-atomic-orbital (GIAO) method with the OPBE functional. The time-dependent density functional theory (TDDFT) was employed to calculate excitation energies, and the electronic transitions over 500 nm are presented with the objective to analyze the transition metal role as an antenna effect in the absorption band in the near-IR region. Finally the ZFS was calculated using Pederson-Khana and coupled perturbed DFT approaches implemented in the ORCA code. The contributions to spin-spin coupling (SS) and spin-orbit coupling (SOC) were analyzed, and the spin-density over the metal centers is discussed employing our scheme of metal-metal communication. Our aim is to determine the influence of the electronic structure over the optical and magnetic properties in a group of model compounds to understand the transition metals effect over these properties.  相似文献   

20.
201×7树脂去除萝卜甙的研究   总被引:2,自引:0,他引:2  
本文研究了用201×7树脂去除萝卜红色素提取液中萝卜甙的方法。试验结果表明:201×7树脂对萝卜甙的静态交换容量最大值可达到72.gmg/ml树脂,吸附平衡时间55分钟,最适pH值5.5。用5BV0.05molNaOH溶液可完全洗脱被交换在树脂上的萝卜甙,洗脱流速1.5BV/hr。去除萝卜甙的提取液真空浓缩,喷雾干燥得粉状萝卜红色素产品,E=4.30。  相似文献   

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