Some properties of solutions for a fourth‐order parabolic equation

This paper is concerned with a fourth‐order parabolic equation in one spatial dimension. On the basis of Leray–Schauder's fixed point theorem, we prove the existence and uniqueness of global weak solutions. Moreover, we also consider the regularity of solution and the existence of global attractor. Copyright © 2012 John Wiley & Sons, Ltd.     

Comparison of LaFeO3, La0.8Sr0.2FeO3, and La0.8Sr0.2Fe0.9Co0.1O3 perovskite oxides as oxygen carrier for partial oxidation of methane

Comparison of LaFeO3, La0.8Sr0.2FeO3, and La0.8Sr0.2Fe0.9Co0.1O3 perovskite oxides as oxygen cartier for partial oxidation of methane in the absence of gaseous oxygen was investigated by continuous flow reaction and sequential redox reaction. Methane was oxidized to syngas with high selectivity by oxygen species of perovskite oxides in the absence of gaseous oxygen. The sequential redox reaction revealed that the structural stability and continuous oxygen supply in redox re-action decreased over La0.8Sr0.2Fe0.9Co0.1O3 oxide, while LaFeO3 and Lao.sSro.2FeO3 exhibited excellent structural stability and continuous oxygen supply.     

Purification and Characterization of the Catalytic Domain of Protein Tyrosine Phosphatase SHP-1 and the Preparation of Anti-ΔSHP-1 Antibodies

This study is focused on the expression of an SH2 domain-truncated form of protein tyrosine phosphatase SHP-1（designated ΔSHP-1） and the preparation of its polyclonal antibodies. A cDNA fragment encoding ΔSHP-1 was amplified by PCR and then cloned into the pT7 expression vector. The recombinant pT7-ΔSHP-1 plasmid was used to transform Rosetta（DE3） E. coli cells. ΔSHP-1 was distributed in the exclusion body of E. coli cell extracts and was purified through a two-column chromatographic procedure. The purified enzyme exhibited an expected molecular weight on SDS-gels and HPLC gel filtration columns. It possesses robust tyrosine phosphatase activity and shows typical enzymatic characteristics of classic tyrosine phosphatases. To generate polyclonal anti-ΔSHP-1 antibodies, purified recombinant ΔSHP-1 was used to immunize a rabbit. The resultant anti-serum was subjected to purification on ΔSHP-1 antigen affinity chromatography. The purified polyclonal antibody displayed a high sensitivity and specificity toward ΔSHP-1. This study thus provides the essential materials for further investigating the biological function and pathological implication of SHP-1 and screening the inhibitors and activators of the enzyme for therapeutic drug development.     

Synthesis, Characterization, and Properties of Supported Tungstozincate Bridged by Co(Ⅱ) Complex Fragment

[CoII(phen)3]2[{(ZnW12O40)CoII(phen)2(H2O)}2CoII(trien)2(NaH2O)2]·3H2O was synthesized via hydrothermal technique and characterized with elemental analyses, IR spectroscopy, TGA-DTA, and variable temperature magnetic susceptibility. The compound crystallized in the monoclinic system with the space group P21/n, a=1.8210 nm, b=2.3592 nm, c=2.2932 nm, β=110.31o, V=9.239 nm3, Z=2, R1=0.0827. The compound consists of two coordination cations, three lattice water molecules, and a macroanion [{(ZnW12O40)Co(phen)2(...     

铈改善TP347H钢的高温持久性能研究

以超临界锅炉管用耐热奥氏体不锈钢TP347H为研究对象,加入0%~0.3%(质量分数)的Ce,用25 kg真空感应炉在氩气保护下熔炼,研究了Ce对TP347H钢高温持久性能等的影响。结果表明:当TP347H中加入Ce量为0.005%时,在750℃,120 MPa时持久寿命达到最大297 h,比未加Ce时提高48%,随着Ce添加量的进一步增加持久寿命逐渐下降,Ce添加量≥0.15%时开始趋于稳定;Ce的添加将导致TP347H钢在高温固溶处理时δ铁素体的形成,Ce的合适添加量约为0.005%~0.03%。     

Continuous flow microfluidic device for cell separation, cell lysis and DNA purification

A novel integrated microfluidic device that consisted of microfilter, micromixer, micropillar array, microweir, microchannel, microchamber, and porous matrix was developed to perform sample pre-treatment of whole blood. Cell separation, cell lysis and DNA purification were performed in this miniaturized device during a continuous flow process. Crossflow filtration was proposed to separate blood cells, which could successfully avoid clogging or jamming. After blood cells were lyzed in guanidine buffer, genomic DNA in white blood cells was released and adsorbed on porous matrix fabricated by anodizing silicon in HF/ethanol electrolyte. The flow process of solutions was simulated and optimized. The anodization process of porous matrix was also studied. Using the continuous flow procedure of cell separation, cell lysis and DNA adsorption, average 35.7 ng genomic DNA was purified on the integrated microfluidic device from 1 μL rat whole blood. Comparison with a commercial centrifuge method, the miniaturized device can extract comparable amounts of PCR-amplifiable DNA in 50 min. The greatest potential of this integrated miniaturized device was illustrated by pre-treating whole blood sample, where eventual integration of sample preparation, PCR, and separation on a single device could potentially enable complete detection in the fields of point-of-care genetic analysis, environmental testing, and biological warfare agent detection.     

CNC车床的故障概率模型

本文从ＣＮＣ车床的故障数据的采集入手,建立了ＣＮＣ车床的故障数据库。应用模糊综合评价的方法对ＣＮＣ车床的故障模型进行了分析     

北京谱仪Ds物理研究新进展

简要介绍了北京谱仪Ｄｓ物理研究的背景,北京谱仪和北京正负电子地撞机已取得的几项物理结果的内容,及其对国际粒子物理研究的贡献。     

基于Hellinger-Reissner变分原理的应变梯度杂交元设计

从一般的偶应力理论出发,基于Hellinger-Reissner变分原理,通过对有限元 离散体系的位移试解引入非协调位移函数,得到了偶应力理论下有限元离散系统的能量相容 条件,并由此建立了应变梯度杂交元的应力函数优化条件. 根据该优化条件,构造了一 个C0类的平面4节点梯度杂交元,数值结果表明,该单元对可压缩和不可压缩状态的 梯度材料均可给出合理的数值结果,再现材料的尺度效应.