Effects of V Addition on Microstructural Evolution and Mechanical Properties of AlCrFe2Ni2 High-Entropy Alloys

The effects of vanadium addition on the microstructural evolution and mechanical properties of AlCrFe₂Ni₂ high-entropy alloy (HEA) were investigated. The results showed that the AlCrFe₂Ni₂V_0.2 HEA was composed of FCC phase, disordered BCC phase, and ordered BCC (B2) phase. With the increase in vanadium content, the formation of FCC phase was inhibited, and a transition from FCC phase to BCC phase occurred. The FCC phase disappeared completely when the value of x exceeds 0.4 in AlCrFe₂Ni₂V_x HEAs. Besides, the amplitude-modulated microstructure morphology transformed from a B2 phase matrix with dispersed BCC nano-phase into an alternating interconnected B2 and BCC phases. Vanadium element has the function of stabilizing BCC phase and B2 phase in AlCrFe₂Ni₂V_x alloys. The hardness of AlCrFe₂Ni₂V_x alloys increased from HV 332.4 to HV 590.7, while the yield strength increased from 765 to 1744.6 MPa with increasing vanadium content, which was mainly due to the decreasing content of FCC phase and the solid solution strengthening of vanadium element. At the same time, the compression ratio of the alloys decreased with the disappearance of the FCC phase. Among the alloys, the AlCrFe₂Ni₂V_0.2 alloy possessed the most excellent comprehensive mechanical properties with yield strength, fracture strength, and compressive ratio 1231.1, 2861.9 MPa, and 44.5%, respectively.     

Developing an Irreversible Inhibitor of Human DDAH‐1, an Enzyme Upregulated in Melanoma

Inhibitors of the human enzyme dimethylarginine dimethylaminohydrolase‐1 (DDAH‐1) can raise endogenous levels of asymmetric dimethylarginine (ADMA) and lead to a subsequent inhibition of nitric oxide synthesis. In this study, N⁵‐(1‐imino‐2‐chloroethyl)‐L ‐ornithine (Cl‐NIO) is shown to be a potent time‐ and concentration‐dependent inhibitor of purified human DDAH‐1 (K_I=1.3±0.6 μM ; k_inact=0.34±0.07 min^?1), with >500‐fold selectivity against two arginine‐handling enzymes in the same pathway. An activity probe is used to measure the “in cell” IC₅₀ value (6.6±0.2 μM ) for Cl‐NIO inhibition of DDAH‐1 artificially expressed within cultured HEK293T cells. A screen of diverse melanoma cell lines reveals that a striking 50/64 (78 %) of melanoma lines tested showed increased levels of DDAH‐1 relative to normal melanocyte control lines. Treatment of the melanoma A375 cell line with Cl‐NIO shows a subsequent decrease in cellular nitric oxide production. Cl‐NIO is a promising tool for the study of methylarginine‐mediated nitric oxide control and a potential therapeutic lead compound for other indications with elevated nitric oxide production, such as septic shock and idiopathic pulmonary fibrosis.     

Electrochemical behavior of microbiologically influenced corrosion on Fe3A1 in marine environment

the passivating film of the inner layer was absolutely destroyed by microbial metabolic products.     

钻孔灌注桩施工过程中的监理要点

目前，建筑物的基础工程采用钻孔灌注桩的越来越多，但是灌注桩在施工过程中常常会出现较多的质量问题，如：桩位偏移、斜孔、塌孔、缩孔、断桩、孔底沉渣过厚、桩基承载力及侧壁阻力下降等。因此，作为监理工作者更要加强在施工过程中的质量控制。     

装配整体式空间钢网格盒式结构在多层大跨工业厂房中的应用

贵州省瓮安县创业园钢结构厂房工程采用装配整体式空间钢网格盒式结构,盒式结构是由钢网格承重式墙架和钢空腹夹层板楼盖结合形成的。采用以层为单位、以单元组装墙架和楼盖的形式来完成多层工业厂房的建设。此种新型结构体系具有用钢量小、跨度大、施工速度快、施工文明的特点。详细介绍了此种新型结构体系的设计要求和施工工艺,对相关工程设计有一定的借鉴作用。     

Experimental study on Ti+Nb bearing ultra-low carbon bake hardening sheet steel hot-rolled in the ferrite region

A Ti+Nb bearing ultra-low carbon bake hardening sheet steel hot-rolled in the conventional austenite region and in the ferrite region with lubrication was experimentally studied.Subsequent cold rolling and continuous annealing processes were also conducted.The results show that microstructures of ultra-low carbon bake hardening hot strips at room temperature are basically irregular polygonal ferrites.The yield strength,ultimate tensile strength,n value,and r value of the No.2 specimen hot-rolled in the ferr...     

也谈变工况除尘系统风机调速计算方法

通过实例对单点变工况，双点、多点变工况，单点、多点变工况与定工况组合的变工况除尘系统进行分析，导出其风机调速的计算方法，并对其除尘特性进行了分析和总结。     

察尔汗盐湖镁资源的开发及展望

察尔汗盐湖不仅具有丰富的镁资源，而且具有开发盐湖的能源，政策优势，由脱水氯化镁可制得多种镁产品。氯化镁脱水技术，氯化镁制金属镁技术是综合开发盐湖水镁资源的关键技术，将纳米技术应用于盐湖镁资源的开发，使镁产品高值化，精细化，将是察尔汗盐湖镁资源的开发方向。     

铜陵一冶环保治理工程的设计

介绍冶炼烟气制本系统环保治理工程的工艺设计及生产运行情况。污水处理系统采用中和曝气加铁盐除砷工艺，引进了戈尔膜过滤器。尾气处理系统，采用石灰中和法，引进动波洗涤技术和关键设备。环保治理工程投产后，废气均达标排放。