两种活性焦脱除烟气中SO2及水洗再生性能对比分析

利用2种原煤制得的活性焦进行烟气脱硫并对脱硫后的活性焦水洗再生试验进行研究。研究发现,高变质煤制备的活性焦NM吸附SO2能力及水洗再生性能均高于低变质煤制备的活性焦SX。水洗再生试验表明,SX活性焦用纯水再生,再生率可达32．67％。用适量碱液再生,再生率可达55．04％,NM活性焦用纯水再生,再生率可达82．43％,用适量碱液再生,再生率可达97．2％。分析焦样发现,碱液再生后SX活性焦平均孔径和比表面积均降低,而碱液再生后的NM活性焦平均孔径和比表面积均有增加。     

硫酸铁改性活性炭催化微波降解甲基对硫磷

在硫酸铁改性活性炭存在下，微波照射能使溶液中的甲基对硫磷迅速降解。对25、100mg／L的甲基对硫磷溶液，改性活性炭0．4g／L，微波照射3．0min，降解率达77．18％。适当提高改性活性炭加入量，同样照射时间即可达96．90％。而采用未改性活性炭甲基对硫磷降解率为93．20％。结果表明，微波照射下改性活性炭的催化活性明显高于未改性活性炭。另外，采用紫外．可见光谱和离子色谱技术探讨了微波照射时间、甲基对硫磷初始浓度和酸度、活性炭用量、改性液硫酸铁浓度和酸度对改性活性炭催化微波降解甲基对硫磷的影响。     

异丁烷脱氢Pt系催化剂研究进展

介绍异丁烷脱氢制备异丁烯Pt系催化剂的研究进展,表明催化剂的活性中心、载体和助剂对异丁烷脱氢反应性能影响较大。催化剂活性中心的积炭覆盖和烧结是催化剂失活的直接原因;载体的酸性有助于调变积炭的形成速率,而活性中心与助剂的交互作用可促使积炭的表面迁移;活性中心与载体的交互作用有利于减少活性中心的烧结。     

活性黄铒染料的制备及其光谱性能

以活性黄和氧化铒为原料,制备了活性黄铒染料,用该染料对真丝绸进行了染色,分别测定了活性黄、活性黄铒的紫外可见光吸收光谱以及染色后真丝绸的红外光谱。在200～800nm范围内,活性黄和活性黄铒的最大吸收峰的波长分别为383nm和380nm。活性黄与铒离子是以配位键相结合,活性黄铒在保持活性黄的上染基团的基础上增加了与真丝绸结合的基团。     

Behavioral responses of sexually active mud snails: kariomones and pheromones

We postulated that kariomones and pheromones function to organize egg capsule deposition and breeding aggregations of mud snails (Ilyanassa obsoleta). Sexually active male and female mud snails were exposed to water-born odors from juvenile snails, nonaggregated female snails, oysters, egg capsule depositing snails, sexually active males, sexually active females, and copulating snails and tested for a follow response using a ring assay. Neither sex responded to juvenile odor or to odor of sexually inactive females. Snails turned and followed water born odors from oysters. when tested with the odors of sexually active males, sexually active females, and copulating pairs, we found sex-specific differences in responses. Sexually active females followed the odor of sexually active males and ignored sexually active female odor. Sexually active males followed the odor of sexually active females and ignored sexually active male odor. Both sexes followed the odor of copulating pairs and egg capsule depositing snails. Snail activities in breeding aggregations are organized by at least three pheromones and one kariomone, and reflect the multifunctionaLity of the aggregations.     

用化学需氧量法测定表面活性剂活性物含量

通过对不同类型表面活性剂（SAA）在不同活性物含量下耗氧量（COD）的测定,SAA的活性物含量与COD存在线性关系,COD值随着活性物含量的增加而增大,且多组分SAA的活性物含量与COD的线性关系可以看成是多个单组分SAA的线性相加,表明,可以通过测定溶液COD值得到活性物含量。     

酶活性部位柔性的分形分析

引言蛋白质三维结构的研究一直是生物学上一个重要而复杂的问题。通过X晶体衍射和核磁共振技术,人们已经积累了大量的蛋白质结构数据,但进一步解析蛋白质结构与功能间的关系,尚存在一定难度。作为非线性科学分支的分形理论(fractaltheory),以其独特的研究方法揭示了自然界中非线性过程内在的随机性及其所具有的特殊规律性。虽然分形理论在20世纪70年代才首次提出[1],但     

En route to complete design of heterogeneous catalysts

Achieving complete control in the synthesis of the active center of a heterogeneous catalyst, which includes the active site, environment around the active site, and the access path is highly desirable but not attainable yet. However, there has been significant progress in recent years that permits a level of control of these properties that are unachievable before. Some illustrative examples are described to demonstrate this in the synthesis of active sites in metal and oxide catalysts and their surroundings. For the active site synthesis, examples include using polynuclear metal complexes as precursors, cluster beam deposition, and use of dendrimers to generate metallic active sites, protection of coordination unsaturation in the synthesis of oxide active sites, and employing silsesquioxane, and unit-by-unit approach. Exfoliation, use of inverse micelles, molecular and macromolecular templating as techniques to exert control of the environment of the active center are also discussed. The limitations of these synthetic methods and remaining challenges are examined.     

CS_2中毒法研究Pt-Al_2O_3系催化剂活性中心的性质

本文对金属催化剂活性中心性质提出了新的表征方法,即用活性频率量度活性中心的强度,用原子组合数的概念描述原子组成活性中心的方式,在此基础上提出了活性频率和活性中心原子组合数的计算公式与新的测定方法。 从测出的活性频率和活性中心原于组合数的数据,发现了Pt-Al_2O_3催化剂具有两种活性中心即α和β中心。α中心CS_2的吸附能力比β中心强,但β中心对环己烷的脱氢活性比α中心强。同时证明了不管在α中心或在β中心上环己烷的脱氢反应都是在双位中心上进行的。 本文还考察了锡和铼对铂催化剂性能的影响,实验表明锡和铼都能从结构效应和电子效应方面影响铂的催化性能。     

无细胞百日咳疫苗中活性PT的保护作用

目的 比较经基因工程方法脱毒的无细胞百日咳疫苗(APV)中不同含量活性PT的保护作用。方法 用小鼠保护性试验(AMPT)评价不同含量活性PT疫苗样品的百日咳效力,组织胺致敏试验(HST)检测不同含量PT样品中PT活性。结果 含5ng活性PT的疫苗与不含PT的疫苗效力差异无显著意义;含50ng活性PT疫苗与不含和含5ng活性PT的疫苗效力差异有显著意义。用HST肛温测定法可以检测到含50ng活性PT的样品中PT活性。结论 AMPT适用于高度脱毒或基因工程脱毒的APV的效力检定,HST肛温测定法可以证实APV中PT的活性。     

Epitaxial Stabilization of Face Selective Catalysts

Selective, active, and robust catalysts are necessary for the efficient utilization of new feedstocks. Face-selective catalysts can precisely modify catalytic properties, but are often unstable under reaction conditions, changing shape and losing selectivity. Herein we report a method for synthesizing stable heterogeneous catalysts in which the morphology and selectivity can be tuned precisely and predictably. Using nanocrystal supports, we epitaxially stabilize specific active phase morphologies. This changes the distribution of active sites of different coordination, which have correspondingly different catalytic properties. Specifically, we utilize the different interfacial free-energies between perovskite titanate nanocube supports with different crystal lattice dimensions and a platinum active phase. By substituting different sized cations into the support, we change the lattice mismatch between the support and the active phase, thereby changing the interfacial free-energy, and stabilizing the active phase in different morphologies in a predictable manner. We correlate these changes in active phase atomic coordination with changes in catalytic performance (activity and selectivity), using the hydrogenation of acrolein as a test reaction. The method is general and can be applied to many nanocrystal supports and active phase combinations.     

活性炭在硫氰酸钠溶剂净化工艺中的应用

将活性炭吸附除杂工艺应用于湿法腈纶溶剂硫氰酸钠的净化,是国内一项独一无二的技术。通过进口活性炭与国内可选的不同种类活性炭特性的剖析,比较了不同特性活性炭的除杂性能。结果表明:活性炭的吸附量与特定孔径范围的孔容成正比。对于硫氰酸钠物料体系,选择中孔(孔半径约为2～5nm)较丰富的活性炭作为吸附剂对系统的除杂效果更好。以此为依据,选取了适合硫氰酸钠物料体系的活性炭,并在实际生产中取得了较好的除杂效果。     

Combinatorial exploration of the catalytic site of a drug-resistant dihydrofolate reductase: creating alternative functional configurations

We have applied a global approach to enzyme active site exploration, where multiple mutations were introduced combinatorially at the active site of Type II R67 dihydrofolate reductase (R67 DHFR), creating numerous new active site environments within a constant framework. By this approach, we combinatorially modified all 16 principal amino acids that constitute the active site of this enzyme. This approach is fundamentally different from active site point mutation in that the native active site context is no longer accounted for. Among the 1536 combinatorially mutated active site variants of R67 DHFR we created, we selected and kinetically characterized three variants with highly altered active site compositions. We determined that they are of high fitness, as defined by a complex function consisting jointly of catalytic activity and resistance to trimethoprim. The k(cat) and K(M) values were similar to those for the native enzyme. The favourable Delta(DeltaG) values obtained (ranging from -0.72 to -1.08 kcal/mol) suggest that, despite their complex mutational pattern, no fundamental change in the catalytic mechanism has occurred. We illustrate that combinatorial active site mutagenesis can allow for the creation of compensatory mutations that could not be predicted and thus provides a route for more extensive exploration of functional sequence space than is allowed by point mutation.     

基于磁流变阻尼器的车辆悬架系统模糊半主动控制

在对磁流变液和磁流变阻尼器的研究基础上 ,以磁流变阻尼器作为半主动控制元件组成模糊半主动悬架系统。运用数值仿真和试验研究等方法对基于磁流变阻尼器的模糊半主动悬架进行了研究。数值仿真和试验结果表明 ,设计的模糊半主动控制算法可对基于磁流变阻尼器的半主动控制悬架实现有效的控制     

用MnO2改善褐煤活性焦脱硫性能的研究

采用加入金属氧化物的方法对褐煤活性焦进行改性，重点研究MnO2的加入对活性焦脱硫性能及再生性能的影响，对活性焦改性前后的性能进行了对比实验。     

新型表面活性离子液体聚集行为的研究进展

基于离子液体的可设计性与功能化,综述了近年来出现的新型表面活性离子液体的结构、性能、聚集行为及其应用的效果,主要包括两性表面活性离子液体、响应型表面活性离子液体、手性表面活性离子液体等。     

Effect of the method of preparation of a Nd2O3-MgO catalyst on its efficiency in the reaction of oxidative coupling of methane

It is shown that the decomposition of a mixture of nitrates or coprecipitated carbonates or hydroxides of Mg and Nd form catalysts manifesting similar catalytic properties, while the catalyst obtained by impregnation is more active but much less selective. The mechanism of formation of the catalytically active phase and the nature of the active sites are discussed.     

硫酸铁改性活性炭催化微波降解甲基橙的研究

在硫酸铁改性活性炭存在下,微波照射能使溶液中的甲基橙迅速降解。对总体积25ml,浓度500mg／L的甲基橙溶液,改性活性炭加入量2．0g／L微波辐射3．0分钟,降解率达76．60％。适当提高活性炭加入量,如3． 0g／L,同样辐射时间可达95．40％。在同样条件下采用未改性活性炭时,其降解率分别为69．53％和90．97％。采用紫外-可见光谱和离子色谱技术探讨了微波辐射时间、甲基橙初始浓度、活性炭用量、改性硫酸铁浓度和溶液酸度对降解甲基橙的影响。     

无机盐对表面活性剂粘度效应的研究

定量研究了多组多表面活性中无机盐对粘度的影响，实验结果表明，无机盐能提高多组分表面活性剂的粘度，但体系中极性活性的组分比例是一个值得注意的因素。     

超临界萃取技术在蓝色化妆品活性成分提取分离中的应用进展

为探讨超临界萃取技术在蓝色化妆品活性成分提取分离中的应用现状,查阅相关文献,并对其进行归纳、分析和总结。结果发现,超临界萃取技术在在多不饱和脂肪酸、多酚、天然色素、萜类等蓝色化妆品活性成分的提取分离中有其独特的优势,可为超临界萃取技术在蓝色化妆品活性成分提取分离中的进一步发展应用提供参考依据。