Photophoretic assembly and migration of dielectric particles and Escherichia coli in liquids using a subwavelength diameter optical fiber

We demonstrate a photophoretic assembly and migration of dielectric (SiO(2) and TiO(2)) particles and bacteria (Escherichia coli) in liquids by using a subwavelength diameter fiber. With a lightwave at 1.55 μm launched into the fiber, the objects are radiated by the leaking light of the fiber to yield negative photophoretic forces which drive the objects to move toward the fiber, with an average assembling/migrating speed of 5-15 individuals per second (ind/s). The influences of laser-on duration, optical power, and size of particles on the photophoretic velocities are also investigated.     

Conformation, activity and proteolytic stability of acid phosphatase on clay minerals and soil colloids from an Alfisol

The present study was carried out to investigate the conformation, enzymatic activity and proteolytic stability of acid phosphatase on montmorillonite, kaolinite and soil colloids from an Alfisol by means of circular dichroism (CD) spectroscopy, isothermal titration microcalorimetry (ITC) and biochemical assay, respectively. The results showed that the secondary structure of phosphatase was changed from disordered type to ordered form during adsorption/desorption cycle, organic substance and 2:1-clay mineral in Brown Soil benefited the formation of ordered structure. Enzymatic activity of phosphatase was inhibited while the proteolytic stability was promoted after the interaction with active particles from permanent charge soil. The decrease of enzymatic activity and the increase of proteolytic stability resulted by montmorillonite and organic colloid were both greater than that by kaolinite and inorganic colloid, which was in consistent with the extent of structural change induced by different colloid particles. Thus, one of the most significant factors responsible for the variation of enzymatic activity and proteolytic stability might be the hiding or even damage of active sites and the irrecognition of cleavage sites in enzyme molecules induced by the formation of ordered structure. The information obtained in this study is of crucial significance for the understanding of the behavior and fate of extracellular enzymes in soils with permanent charges.     

The molecular characterization of weighted Hardy spaces

The molecular characterization of the weighted atomic Hardy space H_w ^p,q,s is given. As an application, the boundedness of Hilbert transform on the weighted Hardy space is proved.     

固态配合物Cr(Ⅲ)(PMBP)_3,Cr(Ⅲ)(TTA)_3,Fe(Ⅲ)(PMBP)_3和Fe(Ⅱ)(PMBP)_2的合成,燃烧热及热分析研究

合成了配合物Fe(Ⅲ)(PMBP)_3,Fe(Ⅱ)(PMBP)_2,Cr(Ⅲ)(PMBP)_3和Cr(Ⅲ)(TTA)_3。用弹式量热计测定了燃烧热。用TG-DTA和DSC法确定了放热峰之一的活化能,反应热和反应级数。     

多孔PVA水凝胶的组成、形貌及泊松比等力学性能研究

制备了不同含量的纯聚乙烯醇(PVA)水凝胶和不同表面活性剂含量的多孔PVA水凝胶,采用数字散斑测量其泊松比,并使用电镜和显微镜观察其微观结构,探讨了纯PVA水凝胶与多孔PVA水凝胶组成、微观结构、泊松比、压缩模量和体积模量的变化及相互关系.研究发现,采用表面活性剂成孔,反复冷冻成型制备的闭孔结构水凝胶,其泊松比随应力应变增加而减小;随PVA含量增加而泊松比值减小;随表面活性剂含量增加,孔径变大,泊松比值减小.PVA水凝胶泊松比值与压缩模量和体积模量的比值成正比.     

嵌段共聚物溶液胶束温度行为的郑电子湮没研究

用正电子寿命技术研究了聚苯乙烯—二甲基硅氧烷／正庚烷二嵌段共聚物溶液胶束的温度行为．结果表明正电子湮没参数对溶液中出现的结构和微观环境的变化十分灵敏．在一定的温度范围o-Ps寿命和强度的陡然变化反映了溶液中共聚物分子聚集态随温度经历不同阶段的变化，超过临界胶束温度o-Ps寿命随温度增高而迅速地增大，这一行为反映了分子聚集体解离成自由共聚物分子的过程．     

Computational studies on density function theory for the bimolecular metathesis reaction CH3+HCl⇔︁CH4+Cl

Density function theory has been applied to alkyl radical reaction to get helpful data for its geometric parameters, energy, and vibrational frequency compared with results obtained by ab initio methods and experimental values. The geometry optimization of the transition state, the precursor complex and the successor complex were performed at the 6‐311G* basis set level. The transition state of the CH₄Cl system of the reaction computed was in agreement with the prediction of Benson. From analysis of the vibration frequency and the net charge on the atom of the precursor complex, transition state, successor complex and the isolated state, the reaction mechanism was derived which we complicated with the bond‐rupture electron‐transfer theory. The atom H in molecule HCl attacks the atom C, forming a transition state via the precursor complex and the electron transfer happens in the precursor complex. The reaction rate of the electron transfer determines the rate of the whole reaction to a certain extent, and active energy, electronic coupling matrix element, and reorganization energy were obtained. © 2001 Wiley Periodicals, Inc. Int J Quantum Chem, 2001     

磁场对复配乳化剂/苯胺微乳液聚合体系相行为的影响

首次在酸性条件下, 以十二烷基苯磺酸钠(SDBS)和聚乙二醇辛基苯基醚(TX-100)为复配乳化剂, 制备SDBS/TX-100/正丁醇(nBA)/苯胺(An)/盐酸(HCl)微乳液体系, 并通过该体系的拟三元相图, 考察了恒定磁场(0.4 T)、助表面活性剂(nBA)与复配乳化剂的质量比(K_m＝m_nBA/m_SDBS/TX-100)及SDBS与TX-100的质量比(S_m＝m_SDBS/m_TX-100)对复配乳化剂/苯胺微乳液聚合体系相行为和电导行为的影响. 结果表明: 随着K_m的增加, 微乳区面积先增大后减小, 当K_m＝1.0时, 形成的微乳区面积最大|随着S_m的减少, 微乳区面积逐渐增大|外加磁场可以增大微乳区面积, 且随着S_m的减小, 磁场对微乳液体系的作用逐渐减弱. 循环伏安的测试结果表明, 复合乳化剂微乳液法制备的聚苯胺, 其循环伏安性能优于单组分乳化剂(SDBS或TX-100)微乳液法制备的聚苯胺.     

咪唑酮并[4,5-c]喹啉衍生物的 合成及体外生物活性

为了合成含有咪唑并喹啉结构骨架的高效PI3K/mTOR抑制剂, 以4-氯喹啉与苯胺的芳香亲核取代(SNAr)反应、 芳香二胺与三光气Traube缩合反应以及双芳基的Suzuki交叉偶联反应等为关键步骤, 合成了15个结构新颖的咪唑酮并[4,5-c]喹啉衍生物(8Aa~8Ae, 8Ba~8Be和8Ca~8Ce). 经核磁共振波谱(NMR)和高分辨质谱(HRMS)分析确证了关键中间体和目标化合物的结构. 采用ADP-Glo激酶试剂盒和TR-FRET mTOR试剂盒法检测了目标化合物对PI3K/mTOR的体外抑制活性, 发现所有化合物均表现出较强的活性.