离子对反相高效液相色谱法测定猪硫酸软骨素的含量

目的：采用离子对反相高效液相色谱法测定猪硫酸软骨素的含量。方法：采用Inertsit-ODS-SP色谱柱（4.6×150 mm,5μm）,流动相：乙腈—0.006 mol.L-1辛烷基磺酸钠溶液（15：85）,磷酸调pH至3.5,流速：0.8 mL.min-1,测定波长：195 nm,进样量：20μL。结果：该方法在质...     

工业生产中醋酸甲酯回收技术的研究进展

综述了聚乙烯醇和精对苯二甲酸生产过程中分离回收醋酸甲酯的主要方法,并对加盐萃取精馏等盐效分离方法、催化精馏方法和萃取精馏方法进行比较研究。结果表明,加盐萃取精馏方法能分离出高纯度醋酸甲酯,且生产工艺简单,有较好的应用前景。     

高频印刷电路基板用树脂及其改性研究进展

介绍了高频电路对印刷电路基板材料的特性参数(如介电常数、介质损耗因数、特性阻抗和玻璃转变温度等)的要求;综述了应用于高频电路基板的树脂基体及其改性体系的研究现状,指出了它们各自的特点和不足;展望了高频印刷电路基板用树脂及其改性的可能发展方向.     

以颗粒煤为助滤剂对城市污泥进行二段过滤脱水的研究

以颗粒煤为助滤剂,采用二段过滤方式来强化城市污泥的脱水,并对滤饼进行热值分析,探讨城市污泥资源化利用前景.在研究中,具体分析探讨了煤的类型、煤的添加比、煤的粒径、搅拌强度、过滤压力以及煤的添加方式对过滤过程中相关参数的影响.得到以下结论:在污泥和煤的添加比为1:2,颗粒煤粒度为0.15～0.18 mm,低强度搅拌,常温...     

丙烯酸酯衍生物的合成研究

研究了近年来国内外对丙烯酸酯及其衍生物合成.按照化学结构将这些衍生物进行分类,系统介绍了烷基化阿烯酸酯、羟基丙烯酸酯、氨基丙烯酸酯、氰基丙烯酸酯和含氟丙烯酸酯等衍生物的合成及其应用.并指出了今后的研究方向.     

无溶剂法合成高固含量水性聚氨酯

以混合二异氰酸酯[六亚甲基二异氰酸酯(HDI)/异佛尔酮二异氰酸酯(IPDI)]和聚己二酸丁二醇酯(PBA-2000)为基本原料、二羟甲基丁酸(DMBA)为亲水性单体[代替目前常用的二羟甲基丙酸(DMPA)]、三乙胺(TEA)为中和剂和乙二胺(EDA)为扩链剂,反应过程中不添加有机溶剂和催化剂,采用先乳化后扩链的预聚体分散法制备了固含量为50%左右的水性聚氨酯(WPU)。采用单因素试验法优选出制备WPU乳液的较佳工艺条件。结果表明:当R=n(-NCO)∶n(-OH)=1.88∶1、w(DMBA)=4.1%和n(EDA)∶n(-NCO)=0.37∶1时,WPU胶膜的强度(拉伸强度为23 MPa)和韧性(断裂伸长率为740%)俱佳。     

纳米氧化亚铜的制备及其应用的研究进展

纳米氧化亚铜是一种新型的 p 型半导体材料,具有活性的空穴-电子对和良好的催化活性,因其独特的性质而在诸多领域有着广泛的应用.总结了近年来制备纳米氧化亚铜的方法,比较了它们在粒径、晶型形态控制以及制备条件等方面的优缺点,并介绍了其性质、应用等方面的研究进展.     

Optimization of the Solvent-Free Lipase-Catalyzed Synthesis of Fructose-Oleic Acid Ester Through Programming of Water Removal

Fructose oleate, an environmentally-friendly biobased surfactant, was prepared using solvent-free suspensions of saccharide in a mixture of acyl donor and monoester (the latter present at ≥5 wt% initially) continuously recirculated through a closed-loop packed bed bioreactor (PBBR)-based system at 53 °C, with the PBBR containing immobilized Rhizomucor miehei lipase (Lipozyme^®IM, Novozymes, Franklinton, NC, USA). To replenish the acyl acceptor consumed during the time course of reaction, the medium was isolated, fructose added, and a suspension formed by rigorous stirring at 80 °C for 6 h followed by centrifugation to remove larger particles, with the placement of the acyl acceptor replenishment treatments during the time course of reaction were optimized. Water removal via free evaporation was augmented during the latter portion of the time course (using a molecular sieve packed column, N₂ bubbling, vacuum pressure, or a combination of the latter two), with an optimal performance achieved when initiating N₂ + vacuum (\( 2. 1 6\,{\text{mg}}_{{{\text{H}}_{ 2} {\text{O}}}} \,{\text{h}}^{{^{ - 1} }} \) removal rate) upon reaching 60% ester, to maintain the liquid-phase water content near 0.40 wt%. When employing the above-mentioned conditions, 92.6 wt% fructose oleate was produced within 132 h, yielding a productivity of \( 0. 2 9 7\,{\text{mmol}}_{\text{Ester}} \,{\text{h}}^{ - 1} \, {\text{g}}_{\text{lipase}}^{ - 1} \).     

冰晶石生产废液在循环冷却水系统中的应用

针对修武化肥厂循环水系统因结垢导致传热效果降低的现象,选择先剥离黏泥,再采用废酸性冰母液在线清洗的方案对其进行综合处理,经分析清洗下来的钙垢量折合成CaCO3垢量为4 764 kg,清洗下来的铁锈垢量折合成Fe2O3垢量为75 kg,除垢率达到95%以上,洗净率达到90%以上,符合国家要求.清洗过程中监测到碳钢挂片腐蚀...     

硫酸铁改性颗粒活性氧化铝除氟的等温线研究

The adsorption equilibrium of a fluoride solution on 1-2 mm granular activated alumina modified by Fe2(SO4)3 solution was investigated. The experiments were conducted using a wide range of initial fluoride concentrations (0.5 to 180 mg•L1 at pH ~7.0) and an adsorbent dose of 1.0 g•L1. The application of Langmuir and Freundlich adsorption isotherm models (linear and nonlinear forms) generally showed that a single Langmuir or Freundlich equation cannot fit the entire concentration gap. Experimental data on low equilibrium concentrations (0.1 to 5.0 mg•L1) was in line with both Langmuir and Freundlich isotherm models, whereas that of high equilibrium concentrations (5.0 to 150 mg•L1) was more in line with the Freundlich isotherm model. A new Langmuir- Freundlich function was used for the entire concentration gap, as well as for low and high concentrations.