Lint on cottonseed by analysis and by nature

The quantative analysis for lint on cotton-seed is successful in the laboratory, in that reproducible results can be obtained. The percentage of lint found cannot be translated to reliable predictions of actual yield values because of the effect on delinting efficiency of variations in seed size and shape, and the proportionate distribution of long and short fibers. Analysis for residual lint on delinted seed does not indicate the cellulose content of second cut linters.     

Mesoporous Silica by Solution-Combustion Synthesis Followed by Etching

Mesoporous silica was synthesized through the solution-combustion process followed by etching with aqueous solution of sodium dodecyl sulfate (SDS). Combustion products were characterized by XRD, FTIR, SEM, TEM, HRTEM, and BET analysis. After etching, the specific surface, mean pore size, and volume of porous space in silica increased up to 390 m²/g, 15 nm, and 1.6 cm³/g, respectively. The synthesized mesoporous silica exhibited good performance in the tests on elimination of methylene blue from aqueous solution.     

氨吸收制冷工艺与压缩制冷工艺的比较

介绍了氨吸收制冷工艺和压缩制冷工艺,并进行了两种工艺的比较,大型煤气化和液化生产企业中采用氨吸收制冷工艺,既回收了余热,又节省了电能,具有很好的经济效益。     

计算机辅助不同溶剂系统两次展开最优化分离

用计算机辅助 ,在两组不同溶剂系统中用两次展开技术与计算机扫描技术相结合来优化展开条件 ,取得了比较满意的结果。     

分步氟化法合成3,4-二氟苯腈的研究

以3,4-二氯苯腈为起始原料,通过分步氟化,实现了高收率制备3,4-二氟苯腈的方法。相比于先前的报道,本工艺不仅收率提高,同时有效地控制了体系焦化、聚合、变黑等高温下不利因素的影响。     

钼系催化丁二烯溶液聚合原位包覆硅藻土

以辛醇取代的MoCl5和Al(i-Bu)3催化丁二烯在硅藻土微孔中进行原位聚合,再用此聚丁二烯同丁苯橡胶(SBR)共混。结果表明,反应具有较好的活性,聚丁二烯能够很好地包覆硅藻土,改善了硅藻土和SBR基体的相容性,提高了硅藻土与SBR共混复合材料的力学性能。     

Hydrogen adsorption by nanostructured carbons synthesized by chemical activation

In this work several samples of Quercus agrifolia activated carbon, the porous structure of which was nanostructured by chemical activation with NaOH and KOH, were evaluated for hydrogen adsorption at 77 K and atmospheric pressure. Hydrogen adsorption reached values in the order of 2.7 wt.% for KOH activated carbon. The mechanism of formation of the porous nanostructures was found to be the key factor in controlling the hydrogen adsorption capacity of chemically activated carbon.     

微波超声波联用萃取白藜芦醇及其苷的HPLC测定

建立了花生芽和葡萄籽微波超声波联用提取白黎芦醇及其苷的HPLC测定方法。采用高效液相色谱进行测定,色谱柱为迪马C₁₈, 流动相为乙腈-水溶液，梯度洗脱，流速1.0 ml/min，柱温为30℃，检测波长为306 nm，进样量为20 μl。白黎芦醇在0.343～15.15×10³ μg/ml范围内呈良好的线性关系，相关系数R² = 0.9967；白藜芦醇苷在110.712～1774.23×10³ μg /ml范围内线性关系良好，相关系数R² = 0.9993。该方法检测快速、简便、重现性好，适用于花生芽和葡萄籽中白藜芦醇及其苷的定量分析。     

层层组装修饰Ni片阳极的光催化辅助电解水制氢

采用层层组装的方法在Ni片阳极上分别组装TiO₂/ZnO纳米棒阵列(TiO₂/ZnONRs)和TiO₂纳米管阵列(TiO₂NTs)。以碱性电解池为基础,采用紫外线辐照阳极,将光催化与电解水有机地耦合在一起,提出并实现了光催化辅助电解水制氢的新过程。通过FE-SEM、XRD、EDS、UV-Vis和光催化辅助电解水制氢(WEAP)等方法,对修饰电极的结构和性能进行了表征和测试。结果表明,TiO₂/ZnONRs比TiO₂NTs修饰Ni阳极的光催化辅助电解水产氢速率快。TiO₂/ZnONRs和TiO₂NTs修饰Ni电极比纯Ni片作阳极的WEAP过程产氢速率分别提高了1.75和1.50倍。电耗分别降低了约10.5%和9.0%。     

化学修饰啤酒酵母菌对铀的吸附特性

以甲醛为交联剂, 将胱氨酸修饰到啤酒酵母菌(SC)上, 并采用海藻酸钠和明胶固定化, 得到一种新型的生物吸附剂--修饰啤酒酵母菌(MSC)。通过红外光谱(IR)分别表征了两种吸附剂的结构, 考察了其吸附铀的主要影响因素即溶液pH值、吸附时间等。结果表明: MSC细胞表面具有大量吸附铀的基团, MSC和SC吸附铀的最佳条件是: pH值为6.0, 相似文献   

Improved Fibroblast Functionalities by Microporous Pattern Fabricated by Microelectromechanical Systems

Fibroblasts, which play an important role in biological seal formation and maintenance, determine the long-term success of percutaneous implants. In this study, well-defined microporous structures with micropore diameters of 10–60 µm were fabricated by microelectromechanical systems and their influence on the fibroblast functionalities was observed. The results show that the microporous structures with micropore diameters of 10–60 µm did not influence the initial adherent fibroblast number; however, those with diameters of 40 and 50 µm improved the spread, actin stress fiber organization, proliferation and fibronectin secretion of the fibroblasts. The microporous structures with micropore diameters of 40–50 µm may be promising for application in the percutaneous part of an implant.     

Protein Separation by Preparative Multicompartment Electrolyzer Secluded by Isoelectric Membranes

Abstract

The performance of a multicompartment electrolyzer using amphoteric isoelectric membranes was studied for preparative isoelectric focusing. The transient behaviors of the electrolyzer were monitored. The current through the electrolyzer and the pH in each chamber were stable during a separation run. Two kinds of protein mixture, bovine serum albumin/myoglobin and bovine serum albumin/β-lactoglobulin, were successfully separated.     

低温余热驱动的合成氨吸收分离及其与冷凝分离的比较

合成氨分离普遍采用的冷凝分离法不仅能耗高,而且不利于氨合成压力大幅度降低。通过对吸收法分离合成氨过程的模拟,分析了驱动热温度、冷却水温度等条件的影响,并将其火用耗与冷凝分离法进行了比较。吸收分离法有利于利用低温余热,并且可在较大的冷却水温度范围内稳定操作;吸收法分离合成氨的火用耗低,不足冷凝法的三分之二;可利用低温余热代替冷凝法所需的昂贵的电能;虽然其冷却水耗量明显高于冷凝分离法,但其影响较小。在较低的合成压力下,吸收法的分离效果显著优于冷凝法,该过程应用于低压合成氨系统非常有利。     

天然胶乳包覆交联聚苯乙烯刚性粒子改性聚丙烯的研究

将天然胶乳包覆到交联聚苯乙烯刚性粒子（N-XPS）上，探讨了N-XPS和包覆剂用量对N-XPS／PP复合材料性能的影响，结果表明：当包覆剂用量为XPS的20％，N—XPS用量为PP的3％时，复合材料的弯曲强度提高30％，简支梁与悬臂梁缺口冲击强度分别提高68％和88％。偏光显微镜观察到加入N-XPS的PP晶粒细化、界面模糊，这一事实证明了N—XPS粒子与PP有好的相容性和诱导结晶成核作用。转矩流变仪测试结果表明：随N—XPS用量的增加，复合材料加料熔融的最大扭矩及物料最低温度有明显的下降，物料达最低温度后，温度增长速率减慢，130s后，温度增长的速率呈上升趋势。     

Toughening by nanostructure

Block copolymer modified epoxy resins have generated significant interest since it was demonstrated that the combination could lead to nanostructured thermosets through self-assembly. Over moderate to high polymer concentration the system behaves as expected for a block copolymer in a solvent selective for one block. Two types of copolymers have been studied: non-reactive and reactive modifiers. Morphologies such as copolymer vesicle and spherical/wormlike micelles can be formed under the appropriate conditions. The enhancement of the modified thermosets' mechanical properties depends on the morphology adopted by the polymers. Besides improving mechanical properties, the morphology was found to also have an effect on the glass transition in the studied systems. In this review we collect the available data on the block copolymers used to fabricate nanostructured epoxy resins and critically appraise the properties reported.