Experimental investigation of the thermally induced vibration of a space boom section

Thermally induced vibration(TIV)is a typical failure of large-scale space structures.This paper reports a laboratory experiment that aims to investigate this unusual structural behavior of complex engineering structures.With the help of a Fourier finite element program,the fixing of a space boom section is well designed so that the TIV can be successfully observed.Although the observed torsional vibration mode is different from the bending vibration mode predicted by the classic theory based on a simple beam model,it can be successfully explained by the general thermal structural interaction theory.This demonstrates the validity of the theoretical model and the necessity of using finite element program to analyze complex engineering structures.     

Investigation of Parameters that Affect Resin Swelling in Green Solvents

The influence of various physical and chemical factors on the swelling of polystyrene and PEG based resins in greener organic solvents has been systematically investigated. In general, chemical factors: the nature of the functionality/linker and the degree of loading were found to have a far larger influence on the swelling of the resins than physical parameters such as bead size. The results are interpreted in terms of Hansen solubility parameters for the solvents and there is evidence that some solvents interact with the polymeric core of a resin whilst others interact with the functionality. The results are extended to a study of the changes in resin swelling observed during both deprotection and chain elongation reactions during solid phase peptide synthesis.     

石墨炉原子吸收法测定生物体液中有机锗

本文研究了石墨炉原子吸收光谱法测定人及动物口服丙氧锗二酸(Ge-132)后血浆及尿中锗浓度的方法。样品无需预先处理,加入Triton X-100后,可直接测定。为排除未消化生物样品对测定的干扰,本法对基体改进剂硝酸镍及硝酸钙的作用进行了比较,认为硝酸镍虽可明显提高水溶液中锗的吸收值,但对血浆中锗的影响不如硝酸钙,且镍浓度的变化对锗吸收的影响也较大,约需3～4mg/ml为宜。而钙剂对血浆及水溶液中锗的影响近似,含钙量大于0.5mg/ml均可获得相同的效果。残留在石墨炉中碳渣的影响不可忽视。本文采用通氧的办法消除了影响。本法绝对灵敏度为34pg/0.0044A,检出下限为1.6×10~(-9)g,线性范围0～200ng/ml Ge,变异系数(4个浓度)1.46～3.1%(n=10),回收率(4个浓度)为95.5～102.6%。     

Introducing a new class of N-phosphoryl ynamides via Cu(I)-catalyzed amidations of alkynyl bromides

We describe here the first synthesis of N-phosphoryl ynamides featuring C- and P-chirality via copper(I)-catalyzed amidative cross-couplings between phosphoramidates and phosphordiamidates with alkynyl bromides. Also featured is a tandem aza-Claisen-hetero-[2+2] cycloaddition for the synthesis of N-phosphoryl azetidin-2-imines.     

One-component bimetallic aluminium(salen)-based catalysts for cyclic carbonate synthesis and their immobilization

The development of one-component, bimetallic μ-oxoaluminium(salen) complexes as highly active catalysts for the synthesis of cyclic carbonates from terminal epoxides is described. The resulting homogeneous catalysts are used in batch reactions at room temperature and one atmosphere pressure. The catalysts have also been immobilized onto various support materials and used in either batch reactions or gas-phase flow reactions with ethylene and propylene oxides. Catalyst lifetime, deactivation and reactivation have been studied in both batch and flow reactions, and it has been shown that of the impurities present in power station flue gas, only sulfur trioxide deactivates the catalyst and at the concentrations of sulfur trioxide present in flue gas, this deactivation would require more than one years exposure of the catalyst to flue gas.     

Preparative-scale isoelectric trapping by recursive electrophoresis in a compartmentalized system having orthogonal primary and secondary pH gradients. Part 1--construction and standard operation

The performance of the current preparative-scale isoelectric trapping systems is limited by the serial arrangement of the separation compartments. A new system has been developed that achieves trapping by recursive electrophoresis in a compartmentalized system (T-RECS). T-RECS features (i) parallel-connected elementary separation heads with independent electrode compartments, feed compartments, and harvest compartments, (ii) orthogonal primary pH gradients and secondary pH gradients, (iii) directionally controlled convective analyte transport along the primary (resolving) pH gradients, and (iv) electrophoretic analyte transport along the secondary (harvesting) pH gradients. The operation of T-RECS has been quantitatively characterized via separation of small molecule ampholytes.     

Preparative-scale isoelectric trapping by recursive electrophoresis in a compartmentalized system having orthogonal primary and secondary pH gradients. Part 2--operation in cascade mode

A parallel multicompartmental electrolyzer recently developed for preparative-scale isoelectric trapping separations, trapping by recursive electrophoresis in a compartmentalized system, was set up to operate as a cascade of binary separations to produce at least one pure target ampholyte (or more, with additional separation heads) without other ampholytes ever entering (even transiently) the harvest stream. This mode of operation avoids the need for exhaustive electrophoresis and the accompanying long separation times brought about by the exponentially decreasing concentrations over the course of batch separations. Continuous operation can be achieved in the cascade mode by continuously feeding the sample into the first separation head configured with three flow-through compartments and continuously harvesting one (or more) target components in additional separation heads configured with two flow-through compartments, attached to the respective branching points.     

Radiation emission from the ＂Rhodotron-TT200＂ cavity

In this paper, the X-rays emitted from the Rhodotron-TT200 cavity have been studied in depth. We found that the Bremsstrahlung interaction is the only contribution of X-ray generation important to safety. The X-ray dose rate in the Rhodotron vault is calculated for normal conditions based on MCNP4C results. The presented calculation shows good agreement with the experimental measurements, which consequently confirms the reliability of the calculation for use in shielding design and other safety aspects.