Pd-Si binary bulk metallic glass

Pd_80+x Si_20−x (x = 0, 1, and 2) binary metallic glasses with the diameter ranging from 7 to 8 mm were prepared by a combination of fluxing and water quenching or air cooling. Thermal analysis results show that with increasing Si content, the glass transition temperature T _g, the initial crystallization temperature T _x and the onset crystallization temperature T _p of Pd-Si binary glassy alloys increase. Moreover, the supercooled liquid region reaches 61 K. It indicates that Pd-Si binary alloys possess large glass forming ability, which can be greatly improved by fluxing treatment. Supported by the National Basic Research Program of China (Grant No. 2007CB613905) and the National Natural Science Foundation of China (Grant Nos. 50671050 and 50431030)     

A functionalized dianthryl tetraaza macrocycle having the recognizing and switching ability

The synthesized macrocycle L is the novel fluorescent receptor having the switching ability by the external stimuli as well as having the recognizing ability of various metal ions. In particular, this macrocycle L shows the possibility of the selectivity of metal ions even in the same charge ions of a different metal, and the values of association constant (M⁻¹) of that for metal ions are consistent with the tendency of increasing charge number of metal ion. In addition, the values of quantum yield (Φ_F) of metal complexes of macrocycle L were ranged from 0.021 to 0.111 enough to recognize the metal ions in macrocycle L. We know from the fluorescent pH titration of macrocycle L by acid/base that the change of fluorescence intersects at about pH=5.     

Analysis of longitudinal multispin orders in strongly coupled spin systems

Longitudinal multispin orders provide an effective way for measurement of scalar couplings and also to probe molecular interactions and dynamics. Analysis of longitudinal orders has been made in strongly coupled AB and ABX spin systems to determine the dependence of strong coupling parameter on these orders. Experimental and simulated spectra of various longitudinal orders are illustrated for these spin systems. This general procedure can be extended to broad range of spin systems to understand the influence of strong coupling on longitudinal orders.     

Synthesis of D-Glucose-based Azacrown Ethers with Phosphinoxidoalkyl Side Chains and Their Application to an Enantioselective Reaction

Five chiral -D-glucose-based monoaza-15-crown-5 ethers with phosphinoxidoalkyl side chains of one to five carbon atoms (5a–e)have been synthesised. The cation binding ability of the new lariat ethers was evaluated bythe picrate extraction method. The substituents at the nitrogen atom were not a major influenceon the cation extraction ability of the azacrown ether; the compounds showed, however, a significant asymmetric induction as phase transfer catalysts in the Michael addition of2-nitropropane to chalcone (95% ee).     

Application of cogwheel phase cycling to sideband manipulation experiments in solid-state NMR

Cogwheel phase-cycling schemes are applied to sideband suppression and sideband separation experiments in solid-state NMR. It is shown that cogwheel phase cycles lead to the elimination of most pulse imperfection effects, while using far fewer experimental signal acquisitions than conventional phase-cycling methods.     

Environmental Effects on the Mechanical Properties of Glass-FRP and Aramid-FRP Rebars

In the paper, the experimental results on the effect of temperature and moisture on the mechanical properties of FRP (Fiber-Reinforced Polymer) reinforcements are presented. FRP rebars made from glass and aramid fibers were subjected to cyclic thermal actions at temperatures ranging between 20 and 70°C, typical of natural hot-climate environments. Tensile tests were also carried out on FRP rebars. The effect of moisture was investigated by cyclic wetting and drying the FRP rebars under laboratory conditions before their testing in tension. Finally, the elastic modulus and tensile strength of the FRP rebars exposed to these cyclic actions were compared with those obtained for unexposed ones, in order to evaluate the mechanical damage caused by environmental conditions.     

Study of Oxidation-Reduction Properties and NO-Donor Ability of Dienediamines in the Indole, Pyrrole, and Thiophene Series

We have conducted an electrochemical study of the oxidation-reduction properties of synthesized dienediamines: derivatives of indole, pyrrole, and thiophene. We have established that reduction of the indicated compounds occurs with successive transfer of two electrons, the first transfer being reversible. We consider the effect of structural factors and the nature of the heterocycle on the ease of reduction of the given compounds. We present the results of an initial study of the NO-donor ability of the compounds upon oxidation.     

以PBL法进行药学实验基本技能教学的探索与实践*

根据西部少数民族地区院校的客观条件和教学特点,提出用以问题为导向的教学法(PBL)进行药学基本技能实验教学。实践证明,实验组(PBL法)的实践基本技能操作水平和发现、分析并解决问题的能力均显著高于对照组(传统教学法)。该法对提高西部少数民族地区药学本科生的创新能力具有较大意义,对其他地区药学本科生创新能力的培养也有一定的借鉴作用。     

企业集团资本增值域的选择与优化

企业集团是资本的集合体，它在资本本质的推动下，不断寻求资本增值的最大化。但是我国企业集团由于受经济体制转换期的影响，以及自身经验的不足，未能正确定位集团的发展领域，从而未能实现资本的增值。文章根据我国企业集团当前存在的问题，结合项目实践中的体会，讨论了如何正确认识资本增值域，以及如何正确选择与优化资本增值域