花斑无须鲶(Ageneiosus marmoratus)全基因组微卫星分布特征研究

根据NCBI已公布的花斑无须鲶全基因组序列,利用MISA软件对花斑无须鲶全基因组的6种完整型微卫星进行筛选并分析其分布特征. 结果如下:在花斑无须鲶全基因组(约1.03Gb)中符合条件的微卫星序列共336 037个,丰度为326个/Mb. 微卫星总长度为7 720 686 bp,占花斑无须鲶全基因组的0.75%. 其中二碱基类型的微卫星数目最多,为145 318个,占微卫星总数的43.24%,其次分别为单碱基(37.12%)、三碱基(11.00%)、四碱基(7.39%)、五碱基(1.04%)和六碱基(0.21%). 花斑无须鲶全基因组微卫星中的优势碱基类别按照数量从高到低排列依次为A、AC、AG、AT、AAT、AAAT、TATC、AAG、AAC和TGA,共有305 243个,占微卫星总数的 90.84%,A、T碱基在微卫星中占绝对优势.     

压力容器缺陷检测及补焊修复

本文对不同种类、结构、工作条件、制造质量压力容器的缺陷检测处理和现场补焊修复的原则和工艺作了详细的叙述。     

管线用钢氢致裂纹(HIC)影响因素分析

研究了管线用钢的化学成分和金相组织对钢的氢致裂纹(HIC)性能的影响。研究认为,带状组织和马氏体含量对HIC性能有很大影响,S含量及Cep对HIC有不同程度影响。含有少量Cu、Ni的钢更适合在酸性环境下使用。     

MICROSTRUCTURE AND MECHANICAL BEHAVIOUR OF Al-Li-Zr AND Al-Li-Cu-Mg-Zr ALLOYS

The aging response,tensile and impact properties of two kinds of Al-Li based alloys havebeen studied.The microstructure,deformation as well as fracture behaviour in the alloys wereobserved with SEM and TEM.It was found that the mechanisms of deformation and fracturefor different heat-treated alloys with the same chemical composition are quite different.Thecauses leading to the drop of ductility,toughness as well as anisotropy in peak-aged alloyshave been analysed.Finally,possible methods to improve the ductility and toughness of the al-loys have been discussed.     

冶金企业面临的严峻局面及今后工作重点

阐述了冶金企业在当前的严峻形势下，要求得生存必须转变传统观念。并提出“九五”期间的工作重点是：节能降耗、调整品种结构、提高生产率及加强决策管理。重点论述了实现节能降耗应抓好的四项工作：连铸坯一火成材与热装直轧，轧钢炉窑节能技术，轧机主传动交流调速技术及控制冷却技术。     

Characterization of wet microalgal cells pretreated with steam for lipid extraction

Steam pretreatment was employed to disrupt microalgal cells for lipids extraction.Effects of steam pre-treatment on microstructure of microalgal cells were investigated through scanning electron microscopy(SEM) and transmission electron microscopy (TEM).Effect of treatment on lipid extraction was also stud-ied.Microalgal cell walls were distorted after steam pretreatment due to the hydrolysis of organic macro-molecules contained in cell wall.Maximum curvature was increased from 1.88 × 10-6 m-1 to 1.43 × 10-7 m-1 after treatment with the steam at 130 ℃.The fractal dimension of microalgal cells increased from 1.25 to 1.30 after pretreatment for 15 min,and further increased to 1.47 when the pre-treatment time was increased to 60 min.Increased steam pretreatment temperature and time enhanced the hydrolysis of organic macromolecules,and finally destroyed microalgal cell walls at pretreatment temperature of 130 ℃ and pretreatment time of 60 min.Lipid extracted from wet microalgal was signif-icantly increased (2.1-fold) after pretreatment.     

Effects of surfactant and particle size on the microstructure and strength of Si3N4 foams with high porosity

The highly porous Si₃N₄ ceramic foams were prepared by direct foaming with mixed surfactants. The surface tension and viscosity of slurries were tailored by different carbon chain length of surfactants and different mean Si₃N₄ particle size to achieve the pore size controlling. The nearly linear relationship between the pore size and the ratio of surface tension to viscosity was observed, which indicates that the pore size could be precisely tailored by the slurry properties. Si₃N₄ ceramic foams with porosity of nearly 94%, mean pore size of 110–230 µm, and compressive strength of 1.24–3.51 MPa were obtained.     

Microstructure and properties of WC-8Co cemented carbides prepared by multiple spark plasma sintering

In this study, WC-8Co cemented carbides were prepared by spark plasma sintering. When the samples sintered at 1300℃ were cooled to room temperature, the samples were sintered multiple times at 1250℃. The changes in microstructure and mechanical properties of WC-8Co cemented carbides prepared by multiple spark plasma sintering were studied. The hardness of cemented carbides increased in the first two sintering, reaching 16.5 GPa. However, the hardness decreased seriously in the last two sintering. The attenuation rates of hardness were 6.2% and 2.5% due to the abnormal coarse grains. Furthermore, the crack path along the grain boundary was almost straight, causing a decrease in the indentation fracture toughness of cemented carbides. Additionally, the grains of cemented carbides were abnormally coarsened, and the morphologies of grains became unstable due to multiple sintering.     

Adsorption Mechanism and Electrochemical Properties of Methyl Blue onto Magnetic CoxCu(1–x)Fe2O4 Nanoparticles Prepared via an Alcohol Solution of Nitrate Combustion and Calcination Process

Journal of Inorganic and Organometallic Polymers and Materials - Magnetic CoxCu(1–x)Fe2O4 nanoparticles were prepared via an alcohol solution of nitrate combustion and calcination process....     

甲醇合成塔用 150 mm SA387Gr22C12 钢板组织和力学性能

对 150 mm 厚 SA387Gr22C12 钢板( / % : 0．13 ～0．14C,0．09Si,0．55 ～0．56Mn,0．004P,0．001S,2．48 ～2． 49Cr,1．11～1．12Mo) 模拟焊后拉伸性能、－29 ℃ 冲击性能、金相组织及回火脆化倾向评定等进行试验,并检测了交货态(正火 + 回火) 、最小模拟焊后态、最大模拟焊后态及步冷试验后的钢板各项性能指标 。结果表明,钢板的回火脆化 倾向不明显,其结果 CvTr55 + 2．5ΔCvTr55 为－63 ℃,完全满足甲醇合成塔用钢板的技术要求。