太钢3#高炉重力除尘器大件吊装

太钢3#高炉大修改造是集团公司重点外部工程项目之一，工程量大，工期紧，施工场地狭小，而质量要求较高。如何采取科学、经济的设备吊装方案，对整个项目经济指标的实现，意义重大。文章详细介绍了太钢3#高炉重力除尘器大件整体吊装方案。通过实际采用，取得良好的经济效果。     

φ3m分级机螺旋轴断裂分析

文章根据电机负荷理论对φ3m分级机螺旋轴进行受力分析，避免了复杂的推导计算和疲劳强度校核。根据现场实际，将机械技术与电气技术结合，分析其断裂原因，提出改进措施，具有较好的效果和借鉴价值。     

THE CARBONITRIDE IN GAS CARBONITRIDING LAYER ON 18CrMnNiMoA STEEL

本文以电解提取-化学分离-X射线衍射逐层相分析及电子显微镜观察、电于衍射、化学分析等综合方法,研究了18CrMnNiMoA钢的气体碳氮共渗层中碳氮化物的形貌、结构、数量、组成、沿渗层的分布以及合金元素在各相间的分配,并对碳氮共渗层的强化机制作了某些讨论.     

Au-Ni-Kovar合金系统基底元素表面偏聚的SAM和XPS研究SCIEI

本文采用SAM和XPS对实用Au-Ni-Kovar合金系统热处理样品(250—350℃,0.5—1.5h)进行了基底元素穿透Au层的表面偏聚研究,给出了这一复杂系统中Ni,Co表面偏聚机理的直观证据,即Ni,Co主要是通过晶界扩散穿透Au层而后以表面扩散覆盖镀Au表面的;表面偏聚元素化学态的研究则不仅表明,氧的吸附和氧化反应是Ni,Co表面偏聚的驱动力,而且发现,上述偏聚会引起样品表面吸水的现象。     

The effects of compressive and tensile prestrain on ductile fracture initiation in steels

It has been recognized that ductility of prestrained steel is inferior to that without prestrain, and the critical equivalent plastic strain of ductile fracture initiation is inversely related to stress triaxiality. In this paper, the effects of compressive and tensile prestrain on ductile fracture initiation in steels are investigated quantitatively by adopting the relationship between stress triaxiality and critical equivalent plastic strain. It is found that compressive prestrain leads to cleavage cracking and reduces ductility. In the case of the TMCP steel, compressive prestrain up to 30% does not decrease the ductility, accompanied by no evidence of cleavage cracks. However, in the case of SM490B steel, 30% compressive prestrain leads to cleavage cracking and reduces ductility significantly.     

Accelerated Discovery of Potent Bioactive anti-TNFα Aptamers by Microbead-Assisted Capillary Electrophoresis (MACE)-SELEX

Dysregulation of tumor necrosis factor-α (TNFα), a pro-inflammatory cytokine, causes several diseases, making it an important therapeutic target. Here, we identified a novel DNA aptamer against human TNFα using in vitro selection, which included a high exclusion pressure process against non-binding and weak binders through microbead-assisted capillary electrophoresis (MACE) in only three rounds. Among the 15 most enriched aptamers, Apt14 exhibited the highest inhibitory activity for the interaction between TNFα and its cognate receptor in mouse L929 cells. For further improving the bioactivity of the aptamer, dimerization programed by hybridization was evaluated, resulting in the Apt14 dimer exhibited a twofold higher binding affinity and stronger inhibition compared to the monomer counterpart. Rapid identification of bioactive aptamers using MACE in combination with facile dimerization by hybridization accelerates the discovery of novel bioactive aptamers, paving the way toward replacing current monoclonal antibody therapy with the less expensive and non-immunogenic aptamer therapy.     

Effects of annealing on Zr8Ni19X2 (X = Ni,Mg, Al,Sc, V,Mn, Co,Sn, La,and Hf): Hydrogen storage and electrochemical properties

The effects of 8-h annealing at 960 °C on the gaseous phase hydrogen storage and electrochemical properties of partial-Ni substituted Zr₈Ni₂₁ alloys were studied. The substituting elements included Mg, Al, Sc, V, Mn, Co, Sn, La, and Hf. Only the main phase of the annealed Sn-substitution remained Zr₈Ni₂₁-structured while those of other substitutions turned into Zr₇Ni₁₀ or Zr₂Ni₇. The observed trend in maximum gaseous phase hydrogen storage capacity followed the increasing order of B/A ratio of the main phase as orthogonal Zr₇Ni₁₀ > tetragonal Zr₇Ni₁₀ > Zr₈Ni₂₁ > Zr₂Ni₇. After annealing, due to the increase in abundance of the main phase, the maximum gaseous phase hydrogen storage capacities of alloys with higher capacities before annealing increased while others decreased. The full discharge capacity also improved in the same increasing order of B/A ratio in the main phase. Hf-substitution showed the highest electrochemical discharge capacity at 200 mAh g⁻¹. After annealing, all alloys with the same main phase as the as-cast alloys showed degradation in full electrochemical capacity due to the reduction in both number and abundance of the catalytic secondary phases. All supplements assisted in improving surface exchange current from the base binary Zr₈Ni₂₁ alloy. Except for La- and Hf-substitutions, annealing reduced the surface exchange current density. The bulk hydrogen diffusion coefficient decreased with most of the supplements except for V- and Sn-substitutions. All supplements, except for Sc, showed improvement in the bulk diffusion after annealing. Furthermore, the maximum gaseous phase hydrogen storage capacity showed a strong correlation to the full electrochemical discharge capacity. Among all alloys in this study, the as-cast Hf-substituted Zr₈Ni₂₁ alloy demonstrated the best overall gaseous hydrogen storage and electrochemical properties.     

喜树碱的合成研究进展

本文对天然抗肿瘤药物喜树碱近几年的合成研究进展作了一综述,参考文献14篇。     

Glucose Production from Maltohexaose as a Substrate by the Bacterial Alpha-amylase-catalyzed Reaction. Its Time Courses Obtained by a Theoretical and an Experimental Approaches

Based on the subsite structure of an α-amylase from Bacillus subtilis, production of glucose from a substrate maltohexaose in the amylase-catalyzed reaction was theoretically predicted as a function of time. The theoretical time course was found consistent with the experimental results, which were obtained by the determination of a product glucose with a commercial assay-kit. Hence, glucose, product from a substrate maltohexaose, will be a useful probe for the amylase-catalyzed reaction.     

An Enzymatic Assay Method for Bacterial Alpha-amylase Using a Glucose Determination-kit and Maltohexaose as the Substrate

Using maltohexaose G₆ as a substrate, a convenient analytical method for amylase-catalyzed hydrolytic reaction was developed by application of an enzymatic assay-kit (glucose oxidase-peroxidase) to measurement of glucose, produced on the reaction: G₆→G₅ + G. The initial velocity was confirmed to be proportional to the initial concentration of amylase, examined, ∼ 100 μm. The new method was found in a good correlation with the Nelson and Somogyi method. Rate assay was also examined: The initial velocity is proportional to the enzyme concentration, ∼ 30 μm. Hence, this enzymatic assay method is recognized to be convenient and useful for the measurement of α-amylase.