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《应用化工》2021,(1):27-31
采用水热法,以SnCl_2·2H_2O和草酸为原料,研究了水热温度、水热时间、PVP-K30和草酸用量对纳米二氧化锡粒度的影响,通过XRD和SEM对纳米二氧化锡的晶型、形貌进行了表征。结果表明,实验所得产物均为四方晶系球形纳米二氧化锡,改变水热温度,可制备出平均粒径在127.7~300.0 nm的纳米二氧化锡;改变水热时间可制备出平均粒径在72.1~180.0 nm的纳米二氧化锡;改变PVP-K30用量,可制备出平均粒径在59.7~180.0 nm的纳米二氧化锡;改变草酸用量,可制备出平均粒径在90.0~460.0 nm的纳米二氧化锡;纳米二氧化锡的粒径随着水热温度的升高和水热时间的延长而增大;随着PVP-K30和草酸用量的增加而减小。SnCl_2·2H_2O的用量0.116 g,PVP-K30用量1.1 g,草酸用量3.15 g,水热温度160℃,水热时间2 h下所制备的纳米二氧化锡的粒径为180.0 nm。 相似文献
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《应用化工》2022,(1):27-36
采用水热法,以SnCl_2·2H_2O和草酸为原料,研究了水热温度、水热时间、PVP-K30和草酸用量对纳米二氧化锡粒度的影响,通过XRD和SEM对纳米二氧化锡的晶型、形貌进行了表征。结果表明,实验所得产物均为四方晶系球形纳米二氧化锡,改变水热温度,可制备出平均粒径在127.7~300.0 nm的纳米二氧化锡;改变水热时间可制备出平均粒径在72.1~180.0 nm的纳米二氧化锡;改变PVP-K30用量,可制备出平均粒径在59.7~180.0 nm的纳米二氧化锡;改变草酸用量,可制备出平均粒径在90.0~460.0 nm的纳米二氧化锡;纳米二氧化锡的粒径随着水热温度的升高和水热时间的延长而增大;随着PVP-K30和草酸用量的增加而减小。SnCl_2·2H_2O的用量0.116 g,PVP-K30用量1.1 g,草酸用量3.15 g,水热温度160℃,水热时间2 h下所制备的纳米二氧化锡的粒径为180.0 nm。 相似文献
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以偏铝酸钠为铝源、硅酸钠为硅源、氢氧化钠为矿化剂、四乙基氢氧化铵为模板剂,在高碱度水热条件下合成了方沸石晶体。采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对合成产物的物相组成和微观形貌进行了表征,并对方沸石晶体的合成机制进行了探讨。利用等温相变动力学原理研究了方沸石晶体生长动力学。结果表明,在180℃下随着反应时间的增加,水热产物的结晶度逐渐增强;水热合成方沸石晶体的Avrami指数n=1.59,说明晶体的形成反应主要以溶解沉淀机制进行。 相似文献
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以水菱镁矿为原料,通过“煅烧-水化-煅烧-水热”的简单合成路线制备了高分散六角片状的阻燃型纳米氢氧化镁。确定初步工艺后,探究了氧化镁用量、水热温度和水热时间对氢氧化镁结晶度和形貌的影响,确定最佳工艺水热条件:氧化镁用量为10%~25%(质量分数)、水热温度为150 ℃、水热时间为3 h。在水热过程中,分别向反应体系中加入聚乙烯吡咯烷酮(PVP)、十六烷基三甲基溴化铵(CTAB)、聚乙二醇6000(PEG6000)和聚乙二醇200(PEG200),考察了不同改性剂及改性剂用量对氢氧化镁颗粒结晶度和分散性的影响。结果表明在4%(质量分数)PVP的条件下,能很好地改善纳米氢氧化镁的分散性,并得到了分散性好、晶形完整、粒径均匀、直径为300~400 nm、厚度为40~60 nm的六角片状纳米氢氧化镁。 相似文献
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高炉渣是钢铁生产过程的主要副产品,是一种多元金属熔体,具有大量显热并能促进焦油及甲烷等低分子碳氢化合物的催化转化。鉴于此本文提出通过干法离心粒化技术将液态炉渣制备成液-固过渡态的高温炉渣颗粒,作为生物质气化热载体,利用炉渣中多种金属矿物对大分子的解构、断键和分解的催化作用,提高气化反应的选择性,实现对炉渣显热的回收和转换,将低品位的液态炉渣余热转换成高品位的氢能。通过气化实验,对影响气化产物分布及气体组成的主要因素进行考察,结果表明:高炉渣在促进焦油分解和碳氢化合物重整方面表现出良好的催化性能,增加热载体炉渣颗粒温度,减小颗粒粒径能够减小炉渣表面积炭,降低气化产物中焦油产率和提升富氢气体品质,在最佳工况下(选用粒径小于2 mm,温度为1200℃的高炉渣颗粒作为热载体),气化产物中焦油含量仅为2.52%,气体产率达到1.65 m3·kg-1,富氢气体中H2含量可达53.22%。 相似文献
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Jeff A. Harding 《乙烯基与添加剂工艺杂志》1996,2(1):87-90
A polycarbonate resin based on a copolymer of bisphenol-A and bisphenol-trimethyl-cyclohexanone was modified with a dispersion of PTFE powder and compared to a standard PTFE lubricated, general purpose BPA-polycarbonate, PTFE is used to lower friction and wear rates in thermoplastics. Mechanicals, thermal properties, limiting PV behavior, and wear rate were measured and compared. 相似文献
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以高产量、高底物转化率和高生产强度为目标,综合运用微生物反应计量学、生化反应和传递动力学、生物反应器工程及代谢工程理论,开发了:(1)基于微生物反应计量学的培养环境优化技术;(2)基于微生物代谢特性的分阶段培养技术;(3)基于反应动力学模型的优化技术;(4)基于代谢通量分析的优化技术;(5)基于系统观点的生物反应系统优化技术。将这些技术广泛应用于多种产品的发酵过程优化研究中并取得了成功。在此基础上总结出“简化、定量化、模型化和阶段化”的发酵过程优化基本原理,这一基本原理对提高我国发酵工业技术水平、促进生物食品产业的健康发展将起重要作用。 相似文献
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Since the implementation of European Union (EU) tire label, the focus of recent attention has been focused on high performance green tire with low rolling resistance, high wet resistance, low noise, and excellent auto-braking properties. However, it is a significant challenge to simultaneously achieve these performances for rubber materials. In this research, we developed a novel concept on the construction of stable ion bonds for high performance high vinyl polybutadiene rubber (HVBR)-based dicarboxylate ionomers. HVBR-based dicarboxylate sodium ionomer (hereafter referred as Na ionomer) was fabricated through complexation reaction of some or all of carboxylic functional groups on the preprepared maleinized HVBR molecular chains with sodium hydroxide. In the case of Na ionomers, the formation of sodium carboxylate group was certified from Fourier transform infrared spectra. Physical and dynamic mechanical measurements indicated that the tensile strength, wear resistance, wet skid resistance, dry sliding resistance, low rolling resistance, and low heat buildup of the Na ionomer were significantly improved compared to that of HVBR, and Na ionomer simultaneously showed better damping properties and the effective damping temperature range was broadened from −8.8 to 30.1°C, which was closer to the room temperature. Consequently, the approach and results collectively represent a significant advance toward the development of high performance green tire rubber materials. 相似文献
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Background
Metabolic rate is known to rise above basal levels after eating, especially following protein consumption. Yet, this postprandial rise in metabolism appears to vary among individuals. This study examined changes in energy expenditure in response to ingestion of a high protein, high fat (HPHF) meal versus an isocaloric high protein, low fat (HPLF) meal in underweight, normal weight, or overweight females (n = 21) aged 19–28 years. 相似文献19.
A novel type of high efficiency, high speed, laboratory still has been developed for obtaining distillation curves on small (5 ml) samples of high boiling (300°F+) materials. The apparatus is simple consisting essentially of a hollow, baffled, horizontal metal bar heated at one end by means of an electrical cartridge heater. In operation, the feed sample is placed in one end of the still, the heater and a vacuum pump turned on, and distillation fractions collected at the other end. Conventional distillation curves are obtained directly. 相似文献
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Polyolefins are generally known either as partially crystalline thermoplastics or as elastomers. With the finding in the ethylene-acenaphthylene copolymer system of the unusual properties of high crystallinity, high modulus, and no independent beta thermomechanical transition at high comonomer contents, it appeared that it might be possible to prepare a block polymer system which would retain the desirable low temperature transition near ?110°C and “hard” acenaphthylene copolymer segments as well. Attempts were made, and the resulting terpolymer is described. An intermediate crystallinity polymer of apparently broad composition distribution was obtained with the modulus of high density polyethylene but the elongational characteristics of low density polyethylene. 相似文献