金属离子在细菌浸取金属硫化矿中的催化作用

用氧化亚铁硫杆菌浸取某低品位原生硫化矿中Ｃｕ、Ｎｉ时，金属离子对细菌浸矿有明显的催化作用．金属离子（Ａｇ＋，Ｈｇ２＋，Ｃｏ２＋，Ｂｉ３＋）能显著提高细菌浸出Ｃｕ、Ｎｉ的浸出率．对细菌浸Ｃｕ而言，金属离子催化能力排序为：Ａｇ＋Ｃｏ２＋＞Ｂｉ３＋＞Ｈｇ２＋；对浸Ｎｉ，其排序则为：Ｂｉ３＋＞Ａｇ＋＞Ｃｏ２＋＞Ｈｇ２＋．金属离子的浓度、性质及矿石粒度等影响金属离子的催化能力．金属离子的催化作用机理与其性质、矿物结构及细菌氧化作用等因素有关     

STUDY ON PHASE-SEPARATION OF PMMA/SAN BLENDS INDUCED BY GLASS BEADS THROUGH DYNAMIC RHEOLOGICAL MEASUREMENTS

Based on the premise that the addition of glass beads （GB） could hardly influence the linear viscoelasticity in low frequency （ω） region for homogeneous polymer systems, the dynamic rheological behaviors of unfilled and filled poly（methyl methyacrylate） （PMMA）/poly（styrene-co-acrylonitrile） （SAN） blends were studied in order to explore the effect of GB on the phase-separation of binary polymer matrix. Results show that GB has an induced effect on the phase-separation, which embodies that the phase-separation temperature （Ts） of PMMA/SAN blend filled with GB is lower than that of the unfilled system. The higher content of GB, the higher is the ＂secondary plateau＂ of ω in the terminal region of storage modulus （G＇） versus ω plot. The ＂secondary plateau＂ appearing in the terminal region is attributed to the phase-separation of PMMA/SAN blends and it becomes more fiat for filled polymer blends under the same conditions. However, it is suggested that this kind of ＂induced effect＂ is related to the GB content; the higher content of GB particles might enhance the interaction between the particles and polymer matrix. Moreover, it is found that the addition of GB also has an influence more or less on the morphology and domain size of polymer matrix. It is believed that the plot of dynamic viscosity （η＇） versus the loss viscosity （η＂） is sensitive to examine the effect induced by GB on the phase-separation of binary polymer matrix.     

IRRAS studies on chain orientation in the monolayers of amino acid amphiphiles at the air-water interface depending on metal complex and hydrogen bond formation with the headgroups

Monolayers of N-octadecanoyl-L-alanine at the air-water interface on pure water and metal ion containing subphases have been studied using polarized infrared reflection-absorption spectroscopy (IRRAS). The metal complex and hydrogen bond formation with the headgroups give rise to a change in chain order depending on metal ion in the subphase. On pure water and Ag(+)-/Pb(2+)-containing subphase, the antisymmetric CH(2) stretching band intensity [nu(a)(CH(2))] undergoes a slower increase than the symmetric one [nu(s)(CH(2))] below the Brewster angle, so the intensity ratios of nu(a)(CH(2))/nu(s)(CH(2)) are less than 1 in the cases of Ag(+) and Pb(2+). Beyond the Brewster angle, the nu(a)(CH(2)) band intensities are substantially reduced in comparison with the nu(s)(CH(2)) ones in the cases of pure water and Ag(+), but the nu(a)(CH(2)) bands still remain negative-oriented in the presence of Pb(2+). These unusual spectral features indicate that the alkyl chains take a preferential orientation with their C-C-C planes parallel to the water surface. The parallel packing of the alkyl chains results from the intermolecular hydrogen bonds C=O...H-N between the neighboring amide groups, strengthened by the metal complex of covalent interaction. On the Ca(2+)-/Cu(2+)-containing subphase, the corresponding polarized spectra display a usual behavior. The alkyl chains are roughly estimated to be inclined around 35-40 degrees from the surface normal on the assumption of chain segment orientation for the monolayers in the liquid-expanded phase. The chain conformation and tilt are closely related to the formation of intramolecular hydrogen bonds and the ionic interaction of the metal complex in the cases of Ca(2+) and Cu(2+).     

[双-(N-苯基水杨醛亚胺)](二氮杂菲)合钴(II)的合成与结构

Bis(N-Phenylsalicylaldiminato)(1,10-Phenanthroline) Co(Ⅱ), C38H28N4O2Co,was synthesized and its crystal structure as been determined by X-ray diffraction method. The crystallographic data are as follows: monoclinic, space group C2/c, α=21.402(7), b=10.060(2), c=14.830(4)Å. β=109.19(2)°, V=3015.8 Å3, Z=4, M=631.57, Dc=1.39g•cm-3, μ=6.35cm-1, F(000)=1308, R=0.061, Rw=1.065. Two N and two O atoms from two bidentate ligands (L), other two N atoms from phen molecule coordinate the central Co(Ⅱ) ion forming octahedral configuration. Co-O, Co-N and Co-N(Phen) bond lengths are 1.995(5), 2.147(5) and 2.224(6) Å, respectively.     

固相配位化学反应研究 ⅩⅩⅩⅦ XRD法研究Cu(Ac)_2·H_2O与甘氨酸的室温固相配位化学反应

固相配位化学研究配位化合物在固态条件下的反应及性质。有关室温条件下的固相配位反应的报导很少。本文用XRD方法研究Cu(Ac)_2·H_2O与甘氨酸在室温条件下的固相配位化学反应,探讨碱对反应产物的影响。 试剂均为分析纯,cis-trans-[Cu(gly)_2)·H_2O按文献[2]合成。实验均在Ar气氛下进行。XRD图用岛津XD-3A型X-射线衍射仪测取,铜靶,扫描速度4°/min。定量分析根据下武:     

Adsorption of liquid mixtures on silicalite-1 zeolite: a density-bottle method

A technique that measures the effective density of a zeolite after adsorption from the liquid phase was developed to measure the absolute amounts of liquid mixtures adsorbed on zeolites without using a nonadsorbing solvent. Since the fugacities of the adsorbing components in solution can be dramatically different with or without the addition of a nonadsorbing solvent, this technique measures mixture isotherms that can be used for analyzing pervaporation through zeolite membranes. A nonideal solution, methanol/acetone, was used as an example to show that its adsorption isotherms on silicalite-1 zeolite at 294 K differ dramatically from those measured with the nonadsorbing solvent method. The methanol/acetone fugacity ratio is different for the two methods because of different concentrations in the liquid phase. Methanol preferentially adsorbs on silicalite-1 at low methanol concentrations and acetone preferentially adsorbs at high methanol concentrations. The density bottle method was used to show that n-hexane preferentially adsorbs from n-hexane/3-methylpentane liquid mixtures, and at high n-hexane concentrations, essentially no 3-methylpentane adsorbs, as has been predicted previously by simulations. A larger molecule, 2,2-dimethylbutane, adsorbed so slowly at 294 K that silicalite had only 16% of saturation coverage after 370 h, but it was saturated after 1650 h; at 423 K, saturation was obtained in less than 24 h.     

Ammonothermal Synthesis,X-Ray and Time-of-Flight Neutron Crystal-Structure Determination,and Vibrational Properties of Barium Guanidinate,Ba(CN3H4)2

We report the crystal structure of Ba(CN₃H₄)₂ as synthesized from liquid ammonia. Structure solution based on X-ray diffraction data suffers from a severe pseudo-tetragonal problem due to extreme scattering contrast, so the true monoclinic symmetry is detectable only from neutron powder diffraction patterns, and structure solution and refinement was greatly aided by density-functional theory. The symmetry lowering is due to slight deviations of the guanidinate anion from the mirror plane in space group P b2, a necessity of hydrogen bonding. At 300 K, barium guanidinate crystallizes in P2₁/c with a=6.26439(2) Å, b=16.58527(5) Å, c=6.25960(2) Å, and a monoclinic angle of β=90.000(1)°. To improve the data-to-parameter ratio, anisotropic displacement parameters from first-principles theory were incorporated in the neutron refinement. Given the correct structural model, the positional parameters of the heavy atoms were also refinable from X-ray diffraction of a twinned crystal. The two independent guanidinate anions adopt the all-trans- and the anti-shape. The Ba cation is coordinated by eight imino nitrogens in a square antiprism with Ba−N contacts between 2.81 and 3.04 Å. The IR and Raman spectra of barium guanidinate were compared with DFT-calculated phonon spectra to identify the vibrational modes.     

在不同复盖度下二组分气体在硅胶上的吸附规律

通过测定不同复盖度下的丙酮－正己烷、苯－正己烷、甲苯－正己烷和正戊烷－正己烷四个二组分气体在硅胶组成吸附等温线，发现它们有着共同的规律，随着复盖度的增加，各体系的组成吸附等温线都逐渐向下靠近它们各自的气液平衡曲线，因此基本上可以反组分吸附相看成二组分液相，其中除了形成最低人沸点的丙酮－正己烷体系以外，其它三个体系的组成吸附等温基本上都可以理想溶液的相对挥发度议程式模拟得到。     

DYNAMIC RHEOLOGICAL BEHAVIOR OF POLYPROPYLENE FILLED WITH ULTRA-FINE POWDERED RUBBER PARTICLES

Dynamic rheological characteristics of polypropylene (PP) filled with ultra-fine full-vulcanized powdered rubber (UFPR) composed of styrene-butadiene copolymer were studied through dynamic rheological measurements on an Advanced Rheometric Expansion System (ARES). A specific viscoelastic phenomenon, i.e. “the second plateau“, appeared at low frequencies, and exhibits a certain dependence on the amount of rubber particles and the dispersion state in the matrix. This phenomenon is attributed to the formation of aggregation structure of rubber particles. The analyses of Cole-Cole diagrams of the dynamic viscoelastic functions suggest that the heterogeneity of the composites is enhanced on increasing both particle content and temperature.     

吗吲哚的示波极谱法研究

在０．１ｍｏｌ／Ｌ Ｈ２ＳＯ４溶液中，吗吲哚出现一灵敏的示波极谱导数还原峰，峰电位为－０．７６Ｖ（ｖｓ．ＳＣＥ），峰电流与吗吲哚浓度在１．０×１０＾－７￣５．０×１０＾－６ｍｏｌ／Ｌ范围内呈线性关系；相关系数为０．９９９８；检出限为３．０×１０＾－８ｍｏｌ／Ｌ。用于片剂测定，得到令人满意的结果，用线性扫描和循环伏安法等手段研究了体系的吸附性和电极反应机理，测定了有关常数和参数。证明该还原波为不可逆