非还原脲变性蛋白溶菌酶稀释复性过程中集聚现象的研究

用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、阴极聚丙烯酰胺凝胶电泳和高效凝胶排阻色谱法, 研究了非还原脲变性蛋白溶菌酶在稀释复性过程中的集聚现象. 实验发现, 在整个稀释复性过程中, 没有蛋白溶菌酶集聚体沉淀产生. 当最终复性液中蛋白溶菌酶浓度小于4.0 mg/mL时, 复性过程中不会形成蛋白溶菌酶分子集聚体; 当最终复性液中蛋白溶菌酶浓度介于4.0～8.0 mg/mL时, 复性过程中会形成由非共价相互作用所引起的蛋白溶菌酶二分子和三分子集聚体; 而当最终复性液中蛋白溶菌酶浓度大于8.0 mg/mL时, 复性过程中除了会形成二分子和三分子蛋白溶菌酶集聚体外, 还会形成四分子蛋白溶菌酶集聚体. 在此基础上, 结合文献, 对非还原脲变性蛋白溶菌酶的稀释复性过程进行了描述.     

负载型纳米二氧化钛对重金属离子吸附性能的研究

采用溶胶-凝胶法制备二氧化钛溶胶, 将其浸渍在硅胶上, 合成了负载型纳米二氧化钛材料, 以X射线衍射(XRD)、扫描电镜(SEM)等手段对其进行了表征. 以ICP-AES为检测手段, 系统地研究了负载型纳米TiO₂材料对重金属离子Cd^2＋, Cr^3＋, Cu^2＋和Mn^2＋的吸附性能. 结果表明, 在pH 8～9范围内, 所研究的重金属离子均可被定量富集, 吸附的金属离子可用0.5 mol/L的HNO₃完全解脱. 负载型纳米二氧化钛对Cd^2＋, Cr^3＋, Cu^2＋和Mn^2＋的静态吸附容量分别为8.3, 13.1, 12.6和5.1 mg/g, 与未负载的纳米二氧化钛相近. 将其应用于环境标准样品中Cd^2＋, Cr^3＋, Cu^2＋和Mn^2＋的分离富集与测定, 结果满意.     

Thermally induced structural transformation of polytriazoleimide to polyindoleimide

A new kind of polytriazoleimide containing bisphenyl-l,2,3-triazole（BPT） was synthesized by copper-catalyzed 1,3-dipolar cycloaddition of azides and alkynes（CuAAC） and polycondensation.The thermal stability and degradation mechanism of the polytriazoleimide were investigated.The results show that the structure of BPT in polytriazoleimide transforms to phenylindole after thermal treatment,accompanying the release of N₂.     

The identification of tricyclic neuroleptics and sulphonamides by high-performance thin-layer chromatography

Circular high-performance thin-layer chromatography (HPTLC) has been used to differentiate a series of twelve tricyclic neuroleptics, using both normal phase and reverse phase procedures. The use of normal phase systems also allows the resolution of geometric isomers of chlorprothixene, clopenthixol and flupenthixol. Thirteen sulphonamides and Trirnethoprim may also be distinguished using HPTLC.     

Hyperbolic Conformal Geometry with Clifford Algebra

In this paper, we study hyperbolic conformal geometry following a Clifford algebraic approach. Similar to embedding an affine space into a one-dimensional higher linear space, we embed the hyperboloid model of the hyperbolic n-space in into . The model is convenient for the study of hyperbolic conformal properties. Besides investigating various properties of the model, we also study conformal transformations using their versor representations.     

Black Hole Entropy: Membrane Approach

The wall contribution character of the Bekenstein–Hawking entropy in the brick-wall model leads us to propose a new method of computing the entropy of a black hole. In our model, the entropy is attributed to the dynamical degrees of the field covering the two dimensional membranes just outside the horizon. A cutoff different from the model of 't Hooft is necessarily introduced. It can be treated as an increase in horizon because of the space–time fluctuations. It is also shown that our method can be applied to the nonstatic case, such as Vaidya–deSitter space–time, and the final result relies on a time-dependent cutoff different from the brick-wall model.     

Direct observation of shear-induced orientational phase coexistence in a lyotropic system using a modified x-ray surface forces apparatus

The second generation x-ray surface forces apparatus (XSFA-II) allows for the first time simultaneous in situ small-angle x-ray scattering and surface force measurements. We have used the XSFA-II to monitor shear-induced orientational transitions in a lyotropic model lubricant system. Upon applying small shear amplitudes (approximately 20 micrometer) to a relatively thick (approximately 800 micrometer) film, we observed evidence for the formation of an orientational boundary layer at the shearing surface. Time-resolved x-ray diffraction revealed the gradual transition to shear-favored orientation by growth of the boundary layer.     

Flux closure structures in cobalt rings

Measurements are reported on the magnetization reversal in submicron magnetic rings fabricated by high-resolution electron beam lithography and lift-off from cobalt thin films. For all dimensions investigated, with diameters of 300-800 nm and a thickness of 10-50 nm, the flux closure state is the stable magnetization configuration. However, with increasing diameter and decreasing film thickness a metastable near single domain state can be obtained during the reversal process in an in-plane applied field.     

Regular solutions of quantum Yang-Baxter equation from weak hopf algebras

Generalization of Hopf algebraslq (2) by weakening the invertibility of the generatorK, i.e., exchanging its invertibilityKK ⁻¹=1 to the regularity K K=K is studied. Two weak Hopf algebras are introduced: a weak Hopf algebrawslq (2) and aJ-weak Hopf algebravslq (2) which are investigated in detail. The monoids of group-like elements ofwslq (2) andvslq (2) are regular monoids, which supports the general conjucture on the connection betweek weak Hopf algebras and regular monoids. A quasi-braided weak Hopf algebraŪqw is constructed fromwslq (2). It is shown that the corresponding quasi-R-matrix is regular R^{w w}R^w=R^w. Presented at the 10th International Colloquium on Quantum Groups: “Quantum Groups and Integrable Systems”, Prague, 21–23 June 2001 Project (No. 19971074) supported by the National Natural Science Foundation of China.