高分子微球的研究现状与发展趋势

介绍了乳液聚合制备法、无皂乳液聚合制备法、悬浮聚合制备法、分散聚合制备法和种子聚合制备法等高分子微球的主要制备方法的特点,并对其在制备聚合物微粒子中的研究现状与发展趋势作了概述。     

多孔氧化物制备方法的研究进展

本文简单介绍了采用共沉淀法、溶胶-凝胶法、浸渍法和水热合成法制备多孔氧化物的原理和特点,详细对比了软模板法和硬模板法在制备多孔氧化物时的原理和特点。以常用的软硬模板为例,概括了模板法制备的氧化物在各个领域的应用;总结了植物模板法的特点,以及近年来以植物为模板制备的多孔氧化物在吸附、催化等方向的应用,并展望了该种方法制备多孔氧化物的研究方向。     

V-P-O催化剂制备方法研究进展

简要介绍了五种V-P-O催化剂的制备方法(传统法、气溶胶法、火焰沉积法、气相法和固态法)和三种耐磨催化剂的制备方法(浸渍法、包容法、嵌入法)。传统法是制备V—P-O催化剂最基本的方法;气溶胶工艺是一种快速干燥制备催化剂的方法;火焰沉积技术是制备纳米级钒磷氧化物的方法之一。     

三代生物柴油的制备与研究进展

综述了三代生物柴油的制备和工艺条件,包括第一代生物柴油制备方法:酸碱催化法、酶催化法和超临界法;第二代生物柴油制备方法:掺炼法、加氢直接脱氧法和加氢脱氧异构法;第三代生物柴油制备方法:微生物油脂法、生物质气化合成法。     

V—P—V—O催化剂制备方法研究进展

简要介绍了五种Ｖ－Ｐ－Ｏ催化剂的制备方法（传统法、气溶胶法、火焰沉积法、气要法和固态法）和三种耐磨催化剂的制备方法（浸渍法、包容法、嵌入法）。传统法是制备Ｖ－Ｐ－Ｏ催化剂最基本的方法;气溶胶工艺是一种快速干燥制备仙化剂的方法;火焰沉积技术是制备钠米级钒磷氧化物的方法之一。     

相变双向调温纺织材料制备技术研究进展

相变双向调温纺织材料是能源领域与纺织行业结合的产物,具有自动双向调温的优点。本文从制备技术的角度出发,分别介绍了相变纤维制备法和后整理法两大途径。围绕相变纤维制备法,详细阐述了微胶囊熔融纺丝法、微胶囊溶液纺丝法、静电纺丝法、PCMs复合纺丝法和纤维中空填充法的原理及应用。针对后整理法,详细介绍了填充法、涂层法、印花法、浸轧法和接枝法的原理及应用。分析了各种制备技术的优缺点,以期从制备技术上加深对相变双向调温纺织材料的认知和理解。制备技术的进步可提高相变双向调温纺织材料的综合性能,如何制备出满足服用要求、综合性能优异的相变双向调温纺织材料是其实现应用的关键。最后,对相变双向调温纺织材料未来的研究方向提出了建议和展望,以期为相变双向调温纺织材料制备技术的研究提供参考和借鉴。     

纳米TiO2薄膜制备方法的研究进展

纳米二氧化钛以其优异的化学、物理性能受到关注。薄膜是纳米二氧化钛的重要形式,制备纳米二氧化钛薄膜具有重要意义和很好的应用前景。依据制备工艺中温度的要求,对制备纳米二氧化钛薄膜的方法进行了概述,高温制备的工艺主要有溶胶-凝胶法、水热法、气相沉积法,低温制备工艺主要有电泳沉积法、紫外光照射法、电化学制备法、模板自组装制备法。     

化学二氧化锰研究进展

综述了化学二氧化锰的制备、应用等方面的研究进展和现状。介绍了几种常用的制备方法,包括：碳酸锰热分解法、硝酸锰热分解法、溶液氧化还原法,以及纳米二氧化锰的制备方法,并分析了这些制备方法的特点。目前化学二氧化锰的主要工业生产方法是碳酸锰热分解法、硝酸锰热分解法和硫酸锰-高锰酸钾氧化还原法。纳米二氧化锰的制备及其应用是未来化学二氧化锰研究的重要发展方向。     

纳米TiO2薄膜制备方法的研究进展

纳米二氧化钛以其优异的化学、物理性能受到关注。薄膜是纳米二氧化钛的重要形式,制备纳米二氧化钛薄膜具有重要意义和很好的应用前景。依据制备工艺中温度的要求,对制备纳米二氧化钛薄膜的方法进行了概述,高温制备的工艺主要有溶胶-凝胶法、水热法、气相沉积法,低温制备工艺主要有电泳沉积法、紫外光照射法、电化学制备法、模板自组装制备法。     

低温液相法制备硫化铋纳米材料的研究进展

文章综述了低温液相法制备纳米硫化铋的最新工艺研究进展。从原料选用、制备工艺、设备等多方面对各液相法包括水热(溶剂热)法、回流法、超声法、微波法、模板法等进行了比较和总结,并深入分析了其制备工艺的发展趋势。     

D113弱酸性树脂对铟(Ⅲ)的吸附性能

研究了D113弱酸性树脂在NaAc-HAc缓冲体系中对铟(III)的吸附性能及机理。对影响树脂吸附容量的不同因素,如溶液的pH、吸附时间和温度进行了研究。结果表明:D113弱酸性树脂对铟(III)的吸附在pH=5.00的NaAc-HAc缓冲体系中最佳,每克树脂在298 K下的静态饱和吸附容量为185 mg;在不同温度下,树脂吸附铟(III)的表观吸附速率常数分别为k288K=2.72×10.5 s.1,k298K=3.69×10.5 s.1,k308K=4.48×10.5 s.1,表观吸附活化能Ea=18.4 kJ.mol.1;测得热力学参数分别为.H=3.27 kJ.mol.1,.S=68.3 J.(mol.K).1,.G298K=.17.1 kJ.mol.1。与Freundlich等温曲线相比,吸附更加符合Langmuir等温曲线。用0.5 mol.L.1 HCl进行解吸时,解吸率为100%。此外,用红外光谱方法探讨了吸附机理,结果显示:D113树脂功能基COOH中的H与In(III)发生了离子交换;同时,C=O中的O与In(III)形成了配位键。     

小叶麦冬果实中微量元素的光谱测定

采用空气-乙炔火焰原子吸收法,对小叶麦冬果实的钙、钠、镁、锌、锰、铜、钾、铁8种元素进行了含量的测定。选择了最佳电离抑制剂和酸性介质。本实验以氯化铯为电离抑制剂,盐酸浓度控制在2%以内,用氯化锶消除磷酸对钙的干扰,使吸光值稳定,用标准曲线法进行测定,获得了满意的效果。该测定方法简便、快速、准确。结果表明,小叶麦冬果实中钾、钙等微量元素含量丰富,含钾17.09mg/g、钙8.22mg/g。     

净化黄磷尾气合成甲酸甲酯研究

用净化黄磷尾气为原料与甲醇液相合成甲酸甲酯 ,并对影响一氧化碳及甲醇转化率、甲酸甲酯时空收率等的因素进行了研究。研究结果表明 ,随着主催化剂浓度或反应压力的增大 ,一氧化碳转化率及甲醇转化率均提高 ;助剂的加入可以大大提高甲酸甲酯时空收率和延长催化剂的寿命。优化的反应条件为 :主催化剂 (甲醇钠 )浓度 0 .4mol L ;助催化剂吡啶浓度 1.74mol L ;温度 80℃ ;时间 160min ;压力 4MPa。在此条件下 ,黄磷尾气中一氧化碳及甲醇转化率可分别达到 95 .5 %和 43%。     

Untersuchung über die agglomeration von polymerisatlatices

Different polymer latices are often incompatible, even when the emulsifying agent is the same in each. If one polymer has a proportion of hydrophilic groups (type ?A”? latex) and the other does not (type ?S”? latex), a mixture of the two latices may coagulate within seconds of mixing. Quite small proportions of type ?A”? will cause agglomeration of the particles of a type ?S”? latex. If 1% of a latex prepared from ethyl acrylate and acrylic acid (95:5) is added to a poly(butylacrylate) latex, D?_w, = 800 Å, and the pH is adjusted to 8–9, the resulting latex is characterized by D?_n, = 6300 Å, D?_w, = 7300 Å; addition of any given type ?S”? latex increases the average particle size still more. The mechanisms involved were studied by observing changes in particle size distribution, by the use of polymerizable dyes as markers, and by electron microscopy. The results of these investigations are : The latices are protected only in some respect by the emulsifier. The protective ionic doublelayer formed by the emulsifier around a type ?S”? particle repels other particles, but not type ?A”? particles. If a collision occours between particles of type ?A”? und type ?S”? they stick together; this process is repeated as often as a type ?S”? particle hits the surface of ?A”?. All the type ?S”? particles of the associate combine to one big particle in such a way that the ?A”? particle stays at the surface and remains active for further agglomeration.     

Effect of preparation conditions on mechanical,dielectric and microwave absorption properties of SiC fiber/mullite matrix composite

Silicon carbide fiber-reinforced mullite matrix (SiC_f/Mu) composites were fabricated via an infiltration and sintering method. Effects of sintering parameters on microstructure, mechanical, dielectric and microwave absorption properties of SiC_f/Mu composites have been investigated. The flexural strength is significantly improved with increasing sintering temperature, and the highest flexural strength of 213?MPa is obtained in vacuum at 1000?°C for 2?h. The performances of composites with different holding time are further studied at 1000?°C. The flexural strengths of composites sintered at 1000?°C for 2 and 4?h reach 213 and 219?MPa, respectively. The failure displacement of the composite sintered at 1000?°C for 4?h reaches 0.39?mm. The excellent microwave absorption properties are achieved for the composite sintered at 1000?°C for 2?h. The minimum reflection loss (RL) reaches ?38?dB with a thickness of 2.9?mm?at 12?GHz and the effective absorbing bandwidth (RL?≤??10?dB) with a thickness of 3.4?mm covers the whole X?band, which indicate that SiC_f/Mu composite is a good candidate for microwave absorbing materials. These results provide valuable solutions to obtaining structural-functional materials for microwave absorption applications in civil and military areas.     

柠檬酸生产工艺技术及进展

介绍了水果提取法、化学合成法、生物发酵法3种柠檬酸的生产方法以及传统生产工艺.详细阐述了目前国内外在开发柠檬酸生产的新原料、改进生产工艺及提取工艺等方面的进展情况,并对各种技术的原理、优缺点、应用等方面进行了论述和比较.     

Multi-response optimization of mechanical properties for ZrWN films grown using grey Taguchi approach

ZrWN nitride films are prepared using direct current (dc) reactive magnetron sputtering. Grey Taguchi analysis is used to determine the effect of deposition parameters (substrate plasma etching time, N₂/(N₂+Ar) flow rates, deposition time, and substrate temperature) on the microstructure and the tribological properties. An orthogonal array, signal-to-noise ratio and analysis of variance are used to determine the effects of deposition parameters. The substrates are pretreated using oxygen plasma etching. The resulting ZrWN coatings are homogeneous, very compact and completely adhered to the substrate. In the confirmation runs, using grey Taguchi analysis, the coefficient of friction decreases from 0.45?±?0.02 to 0.35?±?0.02, the corrosion potential increases from ??0.201?±?0.01 to ??0.072?±?0.01?V, the Vickers hardness increases from 23.63?±?0.07 to 24.65?±?0.05?GPa, and reduced modulus increases from 115.82?±?1.13 to 136.17?±?1.18?GPa. The ZrWN films are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Rockwell C indentation and scratch testing. The TEM pattern for the ZrWN films corresponds to the (111), (200) and (220) planes of the face center cubic structure. Samples with a ZrWN film coating are classified as HF1 and exhibit good adhesive strength. The signal of friction and the associated acoustic emission signal are analyzed, and the scratch profile is analyzed using an optical microscope. Results show that the adhesive force for the critical load Lc2 is about 76.2?±?0.5?N.     

双峰聚乙烯的生产技术及市场前景

介绍双峰聚乙烯的性能特点和用途,阐述双峰聚乙烯的生产工艺、催化剂的研究开发进展以及国内外生产概况,提出了发展我国双峰聚乙烯生产的一些建议。     

雪松松针挥发油成分分析

以无水乙醇、乙酸乙酯、石油醚为溶剂．采用分级萃取的方法分别从新鲜和干枯雪松松针中提取挥发油,利用气相色谱／质谱联用仪(GC-MS)对其化学成分进行分析鉴定。结果表明：新鲜松针中有65种组分,其主要成分是烷烃、烯酸、烯酮、甾醇类,而干枯松针的组分有44种,其主要成分是烷酸、酮类、酯类以及甾醇类物质,其中甾醇类物质的含量比较高。干枯松针中的组分存在形式相对比较稳定。     

CoO/rGO composite prepared by a facile direct-flame approach for high-power supercapacitors

In this study, CoO nanoparticles (NPs) measuring approximately 20?nm in size are successfully grown on reduced graphene oxide (rGO) layers through a facile direct-flame approach. The obtained CoO/rGO nanocomposites are applied as electrode materials and show a high specific capacitance, reaching 1615.0?F?g^?1 at a current of 1?A?g^?1 (737.5?F?g^?1 at 50?A?g^?1), and good cycling stability (88.12% retention after more than 15,000 cycles at 5?A?g^?1), which are outstanding characteristics compared with those of recently reported pseudosupercapacitors. Furthermore, an asymmetric supercapacitor (ASC) produced using CoO/rGO as a positive electrode material and activated graphene (AG) as a negative electrode achieves a high cell voltage of 1.6?V and delivers a maximum energy density of 62.46?Wh?kg^?1 at a power density of 1600?W?kg^?1. The fabrication technique is facile and represents a promising means of obtaining metal oxide/graphene composites for high-performance supercapacitors.