兴安落叶松硫化钠预处理的研究

以１００％和８０％两种硫化度的药液在相同硫化钠浓度、１５５℃下预处理兴安落叶松木片，研究了疏化度及预处理时间对预处理液硫化钠浓度、落叶松主要化学组成及木片中硫含量的影响．结果表明，在较高温度下处理落叶松，药液硫化钠浓度、木材化学组成及木片中硫含量的变化主要发生在预处理的前１小时；８０％硫化度的预处理液中由于存在一定量的氢氧化钠，对得率、木素脱除、抽提物溶出及碳水化合物的降解作用较为强烈；预处理液中硫化钠的消牦仅与初始硫化钠浓度有关，而与硫化度无关，较高的硫化度有利于木片中木素的硫化．     

Synthesis,spectral, structural,Hirshfeld surface and DFT studies on bis(N-(4-fluorobenzyl)-N-(2-phenylethyl)dithiocarbamato-S,S′)zinc(II) and its use for the preparation of ZnS and ZnO nanoparticles

Two new complexes, bis(N-(2-phenylethyl)-N-(4-fluorobenzyl)dithiocarbamato-S,S′)zinc(II) (1) and bis(N-(2-phenylethyl)-N-(4-chlorobenzyl)dithiocarbamato-S,S′)zinc(II) (2), have been synthesized and characterized by various physicochemical techniques. Structure of 1 has been determined by single crystal X-ray diffraction. Complex 1 is a dimer. Zinc atom is four coordinated with a distorted tetrahedral environment. Geometry optimization, geometrical parameters, molecular electrostatic potential (MEPs) and frontier molecular orbital analysis of dimeric and monomeric structures of 1 have been carried out by DFT methods and compared with the experimental X-ray diffraction data. The noncovalent interactions in the complex 1 have been analyzed using Hirshfeld surface analysis. 1 and 2 have been used as single source precursors for the preparation of zinc sulfide and zinc oxide nanoparticles. As-prepared zinc sulfides and zinc oxides have been characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), UV–vis absorption, photoluminence and energy dispersive X-ray spectroscopy (EDS). X-ray diffraction study reveals that zinc sulfides and zinc oxides are composed of rhombohedral and hexagonal phases, respectively. Photocatalytic activities of zinc sulfides and zinc oxides were evaluated by degradation of rhodamine B in aqueous solution under UV light irradiation. The results demonstrated the capability of zinc sulfides and zinc oxides as photocatalyst under UV irradiation to degrade the dye.     

吸湿性PPS共混母粒的制备及性能研究

采用纳米SiO2、间苯二甲酸-5-磺酸钠(5-SSIPA)与聚苯硫醚(PPS)共混,利用双螺杆挤出机制备纳米SiO2/5-SSIPA/PPS共混母粒,采用差示扫描量热仪和扫描电子显微镜研究了纯PPS,SiO2/PPS,5-SSIPA/PPS以及SiO2/5-SSIPA/PPS母粒的吸湿性、热性能和分散性。结果表明:SiO2/5-SSIPA的协同作用较单独添加SiO2和5-SSIPA提高PPS母粒的吸湿性更为显著;随着SiO2/5-SSIPA含量的增加,PPS母粒的吸湿性提高,SiO2/5-SSIPA质量分数为9%时,PPS母粒的含水率达2.7%;SiO2/5-SSIP质量分数为6%时,共混体系的分散性最好;SiO2/5-SSIPA的添加改变了PPS母粒的熔融和结晶行为;在制备吸湿性PPS母粒时,添加纳米SiO2/5-SSIPA按质量比3/5混合,SiO2/5-SSIPA质量分数6%为宜。     

Alumina-supported monoperphosphoric acid for selective oxidation of sulfides to sulfoxides

Selective oxidation of aromatic and aliphatic sulfides to the corresponding sulfoxide was achieved by using POCl₃/H₂O₂ and (alumina-supported phosphorus oxychloride)/H₂O₂. A versatile procedure for the oxidation of sulfides to sulfoxides without any over-oxidation to sulfones has been reported. It is noteworthy that the reaction is clean and tolerates oxidatively sensitive functional groups and the sulfur atom is selectively oxidized.

     

Improvement in mechanical properties of poly(p‐phenylene sulfide) fibers by high‐tension multiannealing method

High‐tension multiannealing (HTMA) was applied to improve the tensile properties of poly(p‐phenylene sulfide) fibers, which was furthermore applied to the fibers produced and improved with the zone‐drawing and zone‐annealing treatments. The HTMA treatment was repeatedly applied to the fibers under the conditions of a 250°C temperature and an applied tension of between 201.0 and 188.0 MPa. As a result, at the 13th treatment the degree of crystallinity increased to 40%. On the other hand, the orientation factor of crystallites increased dramatically to 0.982 during the zone‐drawing treatment, but increased only slightly during the subsequent treatments of zone annealing and HTMA. The finally obtained fiber had a tensile modulus of 10.4 GPa and a tensile strength of 0.73 GPa. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1569–1576, 2000     

小型高砷硫化金矿制酸系统工艺参数的确定

高砷硫化金矿采用一段沸腾焙烧,焙砂提金、烟气制酸.在焙烧温度900～950℃、焙砂颜色控制为深褐色的条件下,高砷硫化金矿脱硫、砷效果较好,焙砂金浸出率达到90%.副产冶炼烟气采用一转一吸工艺制酸,总硫利用率可达92%.     

Study on Polymerization Conditions and Structure of Poly(phenylene Sulfide Sulfone)

High molecular weight linear poly(phenylene sulfide sulfone)s (PPSS) were prepared by aromatic nucleophilic substitution reaction at atmospheric pressure. Influences of various polymerization conditions, such as solvent, catalyst, molar ratio, reaction temperature and time, on the molecular weight of PPSS were examined. The intrinsic viscosity of PPSS obtained under optimum synthesis conditions according to orthogonal experiments was 0.55 dl/g. The results of FT-IR, ¹H-NMR, UV spectrum and Raman spectrum confirmed the linear chain nature of product. The maximum UV absorption of PPSS increased with the increase of its intrinsic viscosity. X-ray diffraction and SALS studies indicated that some local ordered structures formed in the samples annealed between 220 ^○C∼240 ^○C for 4 h. The improvement in thermal performance of PPSS of high molecular weight was confirmed by DSC and TGA experiments.     

Electrochemical behavior of carbon-coated SnS2 for use as the anode in lithium-ion batteries

Carbon-coated SnS₂ nanoparticles were prepared by a simple solvothermal route at low temperature. A carbon coating with a thickness of about 5 nm was deposited on nano-sized SnS₂ particles to serve as the anode in lithium-ion batteries. Both the nanostructure and the morphology of the SnS₂ powders were characterized by X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM). The coated samples were used as active anode materials for lithium-ion batteries, and their electrochemical properties were examined by constant current charge-discharge cycling, cyclic voltammetry and electrochemical impedance spectroscopy. The reversible capacity of the carbon-coated SnS₂ after 50 cycles was 668 mAh/g, which was much higher than that of the uncoated SnS₂ (293 mAh/g). The carbon-coated SnS₂ also had a better rate capability than the uncoated SnS₂ in the range of 0.008-1 C. The capacity retention of the carbon-coated SnS₂ was improved due to its good conductivity and the effective buffer matrix that alleviated volume expansion during the charge-discharge process.     

液化气球罐Zare合金防护层涂装工艺

液化气球罐在使用过程中因球罐内壁存在SSCC(硫化物应力腐蚀开裂)腐蚀环境,造成球罐内壁焊道热影响区出现裂纹,导致球罐内壁腐蚀.本文介绍了采用涂覆稀土合金(Zare)涂层和封闭剂的方法解决液化气球罐内壁SSCC腐蚀问题,着重讨论了球罐内壁防腐涂装工艺及其注意事项.     

Effect of N-substituents on performance of thiourea collectors by density functional theory calculations

Using density functional methods, some properties were studied such as the energies and compositions of frontier molecular orbitals and the atomic charges, which are related to the reactive behavior of thioureas containing different N-substituent groupings. The calculation results indicate that the N-substituent groupings have significant effect on the flotation performance of thiourea collectors. The order of electron-donating ability is N-propyl-N′-benzyl-thiourea (PBZYTU)＞N-propyl-N′-ethyl-thiourea (PETU) ＞N-propyl-N′-allyl-thiourea (PALTU)＞＞ N-propyl-N′-acetyl-thiourea (PACTU) ＞N-propyl-N′-ethoxycarbonyl- thiourea (PECTU) ＞N-propyl-N′-benzoyl-thiourea (PBZOYTU), and the order of feedback-electron-accepting ability is PBZOYTU＞PACTU＞PECTU＞＞ PALTU＞PETU＞PBZYTU. This implies that PBZOYTU, PACTU or PECTU can react with copper atoms having (t2g)6(eg)3Cu(II) or t6e4Cu(I) configuration on the surfaces of copper sulfide minerals through normal covalent bond and back donation covalent bond, and exhibit excellently collecting performance for copper sulfide minerals. These are consistent with the experimental data reported in the literatures.