共查询到20条相似文献,搜索用时 863 毫秒
1.
2.
3.
4.
5.
聚对苯二甲酸乙二醇酯和聚对苯二甲酸丁二醇酯化学扩链反应 总被引:2,自引:0,他引:2
本文综述了用于聚对苯二甲酸乙二醇酯,聚对苯二甲酸丁二醇酯化学扩链反应的羧基加成型和羟基加成型扩链剂,以及缩合型扩链反应,羧基加成型扩链反应,羟基加成型扩链反应和羧羟基同时加成型扩链反应,并讨论了扩链反应,反应特性和扩链产物的性能。 相似文献
6.
聚羟基烷酸酯(PHAs)是一类生物合成的环境友好高分子塑料,具有广泛应用前景。活性污泥合成PHAs可降低PHAs生产成本,实现废物资源化。PHAs的物化性质取决于其单体组分的结构和含量。基于优化PHAs产量的工艺研究,总结了调控活性污泥合成的聚羟基丁酸 羟基戊酸(PHBV)中羟基戊酰含量的工艺措施和生化原理。已有研究表明,好氧时,碳源类型决定PHBV中的单体组分;一般地,溶解氧浓度(DO)降低,PHBV中HV含量会增加;污泥来源、pH值以及碳源与氮磷浓度比的变化都会影响HV含量;各参数对PHAs组分的影响存在关联性。展望了调控活性污泥合成PHAs中单体组分的进一步研究方向。 相似文献
7.
8.
真氧产碱杆菌利用短链有机酸合成聚羟基烷酸酯 总被引:6,自引:0,他引:6
研究了真氧产碱杆菌利用单一以及混合短链有机酸作为碳源进行聚羟基烷酸酯(PHAs)的生物合成. 不同的碳氮浓度比对产物的形成有较大影响;在同样的碳源浓度下,较低氮源浓度更加有利于产物的合成;当短链有机酸浓度为8 g/L、硫酸铵浓度为0.3 g/L时对PHAs的合成最为有利.在4种短链有机酸分别单独用作碳源时,乳酸的消耗速度最快,其次为乙酸、丁酸以及丙酸;在单酸发酵条件下,丁酸的PHAs产量最高(2.72 g/L). 通过比较摇瓶以及5 L罐水平的混合酸发酵发现,发酵罐中的各项发酵指标均优于摇瓶. 研究还发现,真氧产碱杆菌在利用丙酸为碳源进行产物合成时,在发酵后期还伴随有乙酸产生. 相似文献
9.
10.
软链段结构对聚酯弹性体胶粘剂性能的影响 总被引:1,自引:0,他引:1
合成了以聚已二酸-乙二醇聚酯二醇,聚已二酸-丁二醇聚酯二醇,聚已二酸-已二醇聚酯二醇为软链段的含羟基的聚氨酯胶粘剂样品,利用DSC和TEM等现代测试手段对聚氨酯胶粘剂的结晶行为和形态结构进行了表征,并探讨了软链段结构对聚氨酯胶粘剂粘接性的影响。 相似文献
11.
探究了以磷酸分解磷矿,关键酸解工艺参数对磷及Fe、Al、Mg、Pb、As浸出的影响规律,并从热力学角度进行了分析。结果表明,磷矿内磷及Fe、Al、Mg浸出率随磷酸质量分数、反应温度、反应时间和液固比的增大而增大,搅拌速度影响不明显;Pb浸出率随磷酸质量分数、反应温度和液固比的增大而增大,搅拌速度、反应时间影响不明显;As浸出率随反应温度升高呈先增大后减小趋势,随反应时间增加略有减小,磷酸质量分数、搅拌速度和液固比影响不明显。控制磷酸质量分数为30%(以P2O5计)、反应温度为80 ℃、搅拌速度为300 r/min、反应时间为150 min、液固质量比为10∶1,在此条件下,磷及Fe、Al、Mg、Pb、As的浸出率分别为98.65%、68.56%、48.54%、95.84%、32.85%和84.62%。通过热力学分析表明磷矿内Mg、As浸出率较高,Pb浸出率较低,而Fe、Al浸出率大小主要取决于磷矿中褐铁矿及高岭土含量。 相似文献
12.
K. V. Simonov V. V. Zagnoiko L. D. Bocharov 《Refractories and Industrial Ceramics》1989,30(1-2):99-107
Conclusions The most common and characteristic forms of scrap of magnesia parts differing in form, dimensions, and composition are shown. These include deviations of the dimensions from the nominal, breaking off of the corners and edges, nonuniformity, welding together, spots, voids, fire cracks, spalls, and cracks of different origin.The reasons for formation of scrap were determined. The primary of them are the reduced quality of the raw material (chromite, magnesite) with a larger quantity of impurities containing limited silicon and calcium oxides, sometimes insufficient density, grain size, and completeness of hydration of the magnesite powders, nonconformity of the bunker, proportioning, mixing, and pressing equipment to the requirements of modern production of progressive high-quality refractories, the insufficiently high binding capacity of lignosulfonates, deviations in the quality of assembly and finishing of press equipment and automatic ejectors, of the car floor lining, and in firing conditions, a high variation in density of the green parts, and nonuniform heating and cooling in the volume of the parts and of the whole charge during firing. More than 50% of the total scrap of all forms is due to firing scrap of parts.The primary means of reducing or eliminating scrap of parts and simultaneously increasing their quality based on the reasons for formation of different forms of it were noted. These above all else, are increasing the volumes and improving and introduction of new methods of concentration of magnesite and chromite, a successive increase in the share of chrome concentrates, chromium-containing broken parts, and powders by firing of magnesite and caustic dust in the production of magnesia refractory parts as the result of a decrease in the share of commercial natural chromite and magnesite, the use in the production of parts of high-quality type PMSP-93 powder produced in shaft kilns and used as the charge for production of fused materials, the use of the prospect of processes for production of dense periclase powders uniform in chemical analysis from recovered caustic dust, replacement of obsolete mixing and press equipment by more modern, increasing the strength of green parts by above all else improving the binding properties of LST and increasing pressing pressure, forming of the taper of parts by the side plates of the die, improving the quality of assembly and increasing the reliability of functioning of press equipment and automatic ejectors, improving car floor linings, introduction of new methods and increasing the volumes of production of progressive unfired refractories in place of certain forms of fired parts, observation of all production parameters, and a relationship of the wages of labor to the quantity of scrap and the quality of refractories.Introduction of the new management system and the active work of the quality groups created will open up and lead to the action of unutilized reserves for reduction of scrap.Translated from Ogneupory, No. 2, pp. 31–38, February, 1989. 相似文献
13.
A study has been made of the effect of heat, light, time of reaction, and size of sample on iodine numbers obtained by the
Kaufmann method. The iodine numbers of several oils have been determined by this method and compared with those found by other
well-known methods. The formation of acid by the reaction between the Kaufmann reagent and a number of oils, has been investigated.
Presented before meeting of American Oil Chemists’ Society, New Orleans, Louisiana, May 12–13, 1938.
A cooperative organization participated in by the Bureaus of Chemistry and Soils and Plant Industry of the U. S. Department
of Agriculture, and the Agricultural Experiment Stations of the North Central States of Illinois, Indiana, Iowa, Kansas, Michigan,
Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. 相似文献
14.
淋涂玻璃烤漆的研制 总被引:1,自引:1,他引:0
讨论了颜基比、基体树脂/交联剂配比、流平剂种类和添加比例、催化剂种类和添加比例,对涂料的流平性能、涂料在油墨上的重涂性能、涂膜附着力、漆墨层间附着力、涂料遮盖力、干燥速度、储存稳定性以及涂膜耐水性、耐溶剂性及硬度的影响。结果表明:选择有机硅类流平剂添加比例为0.04%0.05%,颜基比为0.8:1,氨基树脂/基体树脂配比为0.3:1,选择长碳链二酸类有机酸催化剂加入比例为0.8%1.0%,在淋涂工艺中于150℃条件下烘烤15min制备成的单组分溶剂性玻璃烤漆涂膜具有优良的遮盖力、耐水性、耐溶剂性、附着力、漆墨层间附着力及高硬度。同时涂料还具有适宜的重涂性能、优良的储存稳定性及较好的流平装饰效果。 相似文献
15.
研究了丁苯橡胶(SBR)1500和1586的生胶门尼黏度(Mv)对混炼胶门尼黏度(Mb),硫化胶的25 min 300%定伸应力(M25)、35 min 300%定伸应力(M35)、50 min 300%定伸应力(M50)、拉伸强度(Ts)及扯断伸长率(Eb)的影响。结果表明,当Mv增大时,SBR 1500和SBR 1586的Mb、M25、M35、M50、Ts和Eb均呈线性增加的趋势,且当Mv每增加1个单位时,SBR 1500的Mb、M25、M35、M50、Ts和Eb分别增加了1.17、0.11 MPa、0.27 MPa、0.56 MPa、0.16 MPa和2.8%,而SBR 1586的Mb、M25、M35、M50、Ts和Eb则分别增加了1.00、0.08 MPa、0.10 MPa、0.57 MPa、0.20 MPa和3.8%;当Mv增加幅度相同时,SBR 1500的Mb、M25、M35增加幅度大于SBR 1586,二者的M50增加幅度相当,而SBR 1500的Ts和Eb增加幅度则小于SBR 1586。 相似文献
16.
17.
泡沫剂辅助蒸汽与孤岛稠油相互作用研究 总被引:1,自引:0,他引:1
模拟了以孤岛现场用DHF作为泡沫剂辅助蒸汽驱过程,泡沫剂浓度为0.2%~1.5%,作用温度为65~200℃,油水质量比为3∶1,作用压力8 MPa,研究其对孤岛稠油界面性质、油品胶体稳定性、四组分组成以及重组分胶粒粒度的影响规律。结果表明,在蒸汽作用下,提高泡沫剂质量分数,可降低稠油-水界面张力,降低油品沥青质组分含量,增大胶质/沥青质之值;沥青质组分分子量减小,沥青质聚沉起始点增大,稠油胶体稳定性提高。在泡沫剂辅助过热蒸汽与稠油作用下,提升作用温度,会引起稠油-水界面张力降低,稠油沥青质聚沉起始点减小,胶体稳定性降低;同时稠油中沥青质组分含量增大,胶质/沥青质的值减小,沥青质组分分子量增大。 相似文献
18.
19.
Solid products of carbonization of residues (i.e. cokes) of vacuum distillation of crude oil, asphalt, and pitch have been studied. The objective was to determine the changes of composition and structure of cokes in relation to temperature. Investigations of elemental composition, functional group content, microscopic analysis, and X-ray diffraction of the products showed that with increasing temperature of carbonization, the degree of structure ordering, the dimensions of the pores, and the intensity of optical anisotropy of the cokes increases, as do the carbon, sulphur, and nitrogen contents; however, volatile matter, hydrogen, and functional-group contents in the cokes decrease. 相似文献
20.
目的 通过对献血员和血站职工等群体普查ABO、Rh、MNSs、Duffy等 12个血型系统抗原 ,建立谱红细胞库和谱红细胞反应格局 ,用于临床鉴定特异性抗体。方法 选用盐水、菠萝酶和间接抗人球蛋白法。结果 筛出 9组O型Rh血型遣传式 (R1R1、R2 R2 、R1R2 、R1RZ、R2 RZ、R1r、R2 r、rr、rr′)和 2 9种抗原 (D、C、E、c、e、Cw、M、N、S、s、P1、Lea、Leb、Fya、Fyb、K、k、KPa、Kpb、Kpc、JSa、JSb、Dia、Xga、Lua、Lub、JKa、JKb、Jra)。结论 精选出 15个O型红细胞组成谱细胞格局 ,有 2 0种抗原鉴定抗体概率符合P <0 .0 5的要求。目的 通过对献血员和血站职工等群体普查ABO、Rh、MNSs、Duffy等 12个血型系统抗原 ,建立谱红细胞库和谱红细胞反应格局 ,用于临床鉴定特异性抗体。方法 选用盐水、菠萝酶和间接抗人球蛋白法。结果 筛出 9组O型Rh血型遣传式 (R1R1、R2 R2 、R1R2 、R1RZ、R2 RZ、R1r、R2 r、rr、rr′)和 2 9种抗原 (D、C、E、c、e、Cw、M、N、S、s、P1、Lea、Leb、Fya、Fyb、K、k、KPa、Kpb、Kpc、JSa、JSb、Dia、Xga、Lua、Lub、JKa、JKb、Jra)。结论 精选出 15个O型红细胞组成谱细胞格局 ,有 2 0种抗原鉴定抗体概率符合P <0 .0 5的要求。 相似文献