粉煤灰、矿渣掺量对胶砂强度的影响

对不同粉煤灰、矿渣掺量的胶砂抗压、抗折强度进行了研究.结果表明,水泥胶砂中随粉煤灰取代水泥量增加,胶砂3d、28d抗压和抗折强度不断减小.水泥胶砂中随矿渣取代水泥量增加,胶砂3d抗压和抗折强度不断减小;当矿渣取代量小于55％时,胶砂28d的抗压和抗折强度均稍有提高,当矿渣取代量大于60％时,胶砂28d的抗压和抗折强度均...     

粉煤灰掺量对矿渣-水泥胶砂耐磨性和强度的影响

研究了粉煤灰掺量对矿渣-水泥胶砂28 d、45 d和350 d耐磨性和强度的影响.在矿渣-水泥胶砂中掺入10%的粉煤灰后胶砂28 d、45 d和350 d耐磨性可增大也可减小,但当粉煤灰掺量≥20%时,均降低,且随粉煤灰掺量继续增加,不断降低.在矿渣-水泥胶砂中掺入10%粉煤灰后胶砂28 d、45 d强度减小,且随粉煤灰掺量继续增加,不断减小.在矿渣-水泥胶砂中掺入粉煤灰后,胶砂350 d强度可增加也可降低,取决于粉煤灰掺量和矿渣取代水泥量.随掺粉煤灰的矿渣-水泥胶砂强度增大,胶砂磨损率总体趋势减小,但并不单调减小.     

矿渣掺量对胶砂和混凝土强度的影响

本文研究了矿渣掺量对胶砂强度、混凝土强度和混凝土与钢筋的粘结强度的影响.在水泥胶砂或粉煤灰-水泥胶砂中,用矿渣取代部分水泥后,胶砂3d强度会降低,且随取代量增加,胶砂3d强度逐渐降低.在水泥胶砂或粉煤灰-水泥胶砂中,当矿渣取代水泥量≤55％时胶砂28 d强度会增加,但矿渣取代水泥量至60％时胶砂28 d强度会下降.在水泥混凝土或粉煤灰-水泥混凝土中,当矿渣取代水泥量≦50％时混凝土28 d强度及其与钢筋的粘结强度会提高,但矿渣取代水泥量≥60％时混凝士强度和粘结强度会降低.     

再生微粉与矿渣对水泥性能的不同影响

通过试验,对再生微粉、生产用矿渣进行了对比研究,了解了再生微粉、矿渣掺量对水泥性能影响的差异.试验表明,各龄期水泥胶砂强度随着再生微粉和矿渣掺量的增加而降低;随着再生微粉和矿渣掺量的增加,水泥胶砂流动度呈现逐渐减小;再生微粉和矿渣粉的加入使净浆的初凝时间缩短,且初凝时间随着掺量的增大而减小.     

陶瓷掺合料对水泥胶砂性能的影响研究

为了研究陶瓷粉作为水泥基掺合料的可行性,采用水泥胶砂强度检验方法,研究水泥胶砂性能随陶瓷粉掺量、养护龄期的变化特征,并分析探讨了陶瓷粉作为掺和料的工作机理.研究表明:随着陶瓷掺量的增加,陶瓷粉水泥胶砂试块强度降低,当陶瓷掺量为30％时,水泥砂浆试块的强度仍满足水泥性能要求.对比掺有陶瓷粉、粉煤灰和硅灰三种材料的水泥胶砂试块的28 d强度随取代率的变化曲线,其中陶瓷粉水泥胶砂试块性能最优,且陶瓷粉水泥胶砂强度变化曲线与粉煤灰水泥胶砂相似.     

基于冲填砂浆结石技术的混合砂浆性能正交性试验研究

为了研究水胶比、粉煤灰掺量和沙漠砂取代率对冲填砂浆结石技术的混合砂浆性能的影响,采用粉煤灰部分取代胶凝材料,沙漠砂代替中砂,拌制砂浆,并进行正交性试验.通过层次分析和综合平衡分析得到各因素、各水平的影响权重和最佳配比方案.结果表明:沙漠砂取代率和粉煤灰掺量是影响砂浆稠度的主要因素,粉煤灰掺量是影响分层度和28 d抗压强度的主要因素,而影响90 d抗压强度主要因素的是水胶比.对于一般工程项目,由各因素、各水平的权重之和得到的最优试验组合为:水胶比为0.975,粉煤灰掺量为20％,沙漠砂取代率为20％.最优配比均能满足砂浆强度M10砂浆的配制要求,且经济合理.     

矿渣掺量对水泥胶砂耐磨性和强度的影响

研究了不同矿渣掺量的水泥胶砂28d、45d和350d龄期耐磨性和强度。在水泥胶砂中掺入矿渣等量取代部分水泥后水泥胶砂28d、45d和350d龄期耐磨性均降低,且随矿渣掺量增加,水泥胶砂各个龄期耐磨性逐渐降低。在水泥胶砂中掺入矿渣等量取代部分水泥后,水泥胶砂28d、45d和350d龄期强度均随矿渣掺量增加先增加后降低。掺矿渣胶砂的耐磨性随胶砂强度增大并不单调增加,强度相同的矿渣胶砂常常表现出不同的耐磨性。     

掺低熔点玻璃粉水泥胶砂的耐热性能研究

对掺低熔点玻璃粉水泥胶砂性能进行了研究.测试了不同煅烧温度前后试件的抗压强度和抗折强度,分析了强度残值率、脆性系数和微观结构.试验结果表明,低熔点玻璃粉能显著改善水泥胶砂在高温煅烧(900℃)时的耐热性能,提高强度残值率和降低脆性系数,尤其与粉煤灰或矿渣粉复掺时效果更好.当掺10％低熔点玻璃粉和15％粉煤灰时,抗压强度残值率改善幅度最高,达40％,抗折强度残值率改善幅度达48％,脆性系数最低,为5.63;掺10％低熔点玻璃粉和15％矿渣粉的水泥胶砂,抗压强度残值率为52％,抗折强度残值率为50％.     

废钢化玻璃微粉作矿物掺合料的试验研究

对不同掺量废钢化玻璃微粉的水泥净浆、胶砂试件及混凝土的力学性能进行了研究。结果表明:废弃钢化玻璃微粉具有火山灰活性,但其活性略低于粒化高炉矿渣,粉磨1 h的钢化玻璃微粉活性最好,达到76.5%。胶砂试件中废钢化玻璃微粉取代水泥的掺量不宜超过25%,掺量20%时,混凝土强度与不掺基准组相当,水泥胶砂试件120 d的抗压强度和抗折强度分别达到56.0 MPa和12.2 MPa,分别高于基准组1 2.2%、31.2%。     

掺脱硫粉煤灰的水泥胶砂试验研究

通过试验研究了脱硫粉煤灰等量取代普硅水泥对胶砂强度的影响,试验表明：不掺激发剂的胶砂强度部分高于空白组,但对掺量有一定限制;掺适量激发剂的胶砂表现出较好的激发效果;但脱硫粉煤灰品质要达标且需要选择合适的激发剂,且激发剂的掺量要控制在5％以内比较适中。     

乙苯,苯乙烯的生产及合成乙苯,苯乙烯催化剂的研究进展

苯乙烯是重要的石油化工原料。本文介绍了国内外苯乙烯生产的发展概况，合成乙苯，苯乙烯所用的催化剂种类，并就苯乙烯生产及催化剂的发展趋势提出了自己的观点。     

Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Various homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, ¹³C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo- and copolymers, as expected. © 1993 John Wiley & Sons, Inc.     

生物质气化及生物质与煤共气化技术的研发与应用

总结了生物质原料的特点及生物质单独气化的缺点;介绍了国内外生物质气化技术及生物质与煤共气化技术的研发与应用现状;分析了在此领域国内外的发展趋势与前景;概括了开展生物质与煤共气化技术研发的意义。     

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

The variation of the Au 4f binding energy of Au clusters with the cluster size has been established by measuring the binding energies of clusters whose size distributions were independently determined by HREM and STM. The binding energy increases significantly when the cluster size is less than 2 nm. Au-Cu bimetallic clusters of the composition Cu₃Au have been deposited for the first time on carbon substrates. The shifts in the core level binding energies of the bimetallic clusters show the effect of alloying in the case of large clusters, but show effects of both alloying and cluster size in the case of the small clusters. The interaction of CO with Cu₃Au clusters is stronger than with a bulk Cu metal. The interaction of CO with small Cu clusters also seems to be stronger than with bulk Cu or with large Cu clusters.     

钾盐资源及钾肥供需情况分析及预测

阐述了国内外钾盐资源及钾肥生产现状,对国内外钾盐的供需形势进行了分析及预测,从资源、原材料、国际市场三方面提出了解决我国钾盐短缺的措施。     

Kinetics and Mechanism of Oxidation of Mono- and Polyacetals

Abstract

Kinetics and mechanisms of oxidation of 6 acetals by molecular oxygen and ozone in liquid phase have been studied. Reaction with molecular oxygen (70°C, 15–16 hr) leads to the formation monoethers of the corresponding glycols with 68–90% selectivity. Salts of metals and complexes with crown-ethers have increased the reaction rate significally. Ozone have reacted with acetals with formation similar products. The mechanisms of intermediate stages have been proposed.     

Comparison of the Adhesion and Cohesion of Triblock and Random Copolymers of Styrene and Butadiene

A substantially greater detachment energy is required to strip a polyethylene tereph-thalate (Mylar) film from a styrene-butadiene-styrene (SBS) triblock copolymer compared to that for peeling from a random styrene-butadiene (SBR) copolymer. This is true even though the intrinsic interaction between the Mylar and each elastomer is expected to be similar because of their virtually identical chemical composition. It is proposed that this difference in peel strength (between the SBS and SBR) is a consequence of the much higher dissipative capacity of the former elastomer. Another manifestation of this is the higher cohesive tear strength of the SBS compared to the SBR. Extents of energy dissipation within each elastomer during detachment of the Mylar adherend are consistent with the hypothesis that the average maximum stress experience before detachment is some similar fraction of each elastomer's tensile strength.     

责任和责任心的涵义与结构

责任是人应主动承担的角色义务和对其因过失所造成后果应承担的责罚.有两层涵义:一是义务;二是后果.责任心是个体自觉做好分内事务和履行道德义务的心理倾向,是个性心理品质成分中自我特征维度上的重要内容.责任心具有两个方面的涵义:一是角色分内职责;二是角色道德义务.责任心是一种通过责任认知、责任个性和责任适应的动态形式表现出来的静态品质,责任心是责任心过程结构与责任心关系结构相互制约、相互影响的统一体.     

二甲基二烯丙基氯化铵和丙烯酰胺的合成及应用

用复合引发体系(过硫酸盐-偶氮类引发剂)和脂肪胺类氧化还原体系引发,在实验室获得了单体转化率≥98%,特性粘数高于13.6 dL/g的阳离子共聚物PDA,探讨了控制聚合物分子量的影响因素.     

Wetting properties of homopolymers and copolymers of pentafluorostyrene and methylacrylate and homopolymer blends

Polypentafluorostyrene (PPFS), polymethylacrylate (PMA), and poly(pentafluorostyrene-co-methylacrylate), poly(PFS-co-MA) were prepared and the wetting characteristics of polymer blends of PPFS and PMA were compared with that of poly(PFS-co-MA) via contact angle measurements. The critical surface tension of polypentafluorostyrene was found to be 22.6 dyne/cm, which is comparable to the value reported for polytrifluoroethylene (22 dyne/cm). The critical surface tension of poly(PFS-co-MA) is not linearly related to its composition. The polymer blends of PPFS and PMA exhibit significant surface enrichment of the fluoropolymer. The harmonic-mean method¹ was employed to determine surface tensions of these polymers and many known polymers. It is found that the method produces useful surface tension data provided the contact angle values are derived from testing liquids of dissimilar polarity.