Fe~(2 ),NH_4~ 对氧化亚铁硫杆菌氧化黄铁矿的影响

采用摇瓶试验方法,探讨了浸矿初期介质中Fe2 ,NH4 对T·f菌氧化黄铁矿的影响,试验表明,Fe2 ,NH4 的存在有助于提高生物活性和生物量,Fe2 的浓度在420～640mg／L之间,pH值在1．8左右,可明显减少沉淀物的产生,有利于浸矿的有效进行．     

基于阅读2.0模式,高校馆学生读者网络阅读推广分析

阅读2.0是全民阅读推广的新理念.本文简述了阅读2.0的明显特征及两大优势,并结合长春高校图书馆的调查数据,分析了高校大学生网络阅读现状.     

单试样三点柔度法测金属材料JR曲线及其条件起裂值

在单试样卸载柔度法及单试样三曲线法基础上,提出了一种更简便的测定金属材料ＪＲ曲线及其条件起裂值的单试样三点预先度法,并用该方法测定了１Ｃｒ１／２Ｍｏ钢、１６ＭｎＲ风和ＷＣＦ６２钢的ＪＲ曲线及其条件起裂值,与标准的多试样法相比,误差均在工程许可范围内。     

Microstructure developed in the surface layer of Ti-6Al-4V alloy after sliding wear in vacuum

Microstructural changes in the surface layer of Ti-6Al-4V alloy after sliding wear in vacuum have been studied by means of scanning and transmission electron microscopy (SEM and TEM). The wear rates of Ti-6Al-4V alloy in vacuum were measured under different sliding velocities and loads. The experimental results showed that a severely deformed layer with a grain size of 50–100 nm and thickness about 70 μm was formed underneath the worn surface. Under the slower sliding velocities, the substructure of the layer had a high dislocation density, while under higher sliding velocities, twins were found to exist in the substructure. A process by which the deformed layer formed has been proposed and the deformation of materials at the contacting spots of the Ti-6Al-4V sample is discussed.     

Analysing the shielding effect of a concrete wall reinforced with steel plate using generalised surface integral equations

The electromagnetic shielding effect of a two-dimensional concrete wall reinforced with steel plate is analysed using a generalised surface integral equation (GSIE) method developed from Huygens? equivalence principle. The wall is divided into small blocks. Each block is analysed independently at first, and its electromagnetic characteristics are expressed by an associated generalised transition matrix defined on the reference surface of that block. In order to find the electromagnetic characteristics of the whole system, a GSIE formulation is established on the reference surface of all blocks, which can be solved efficiently using characteristic basis functions.     

Myoglobin/gold nanoparticles/carbon spheres 3-D architecture for the fabrication of a novel biosensor

A novel biosensor based on a myoglobin/gold nanoparticles/carbon spheres (Mb-AuNPs-CNs) 3-D architecture bioconjunction has been fabricated for the determination of hydrogen peroxide (H₂O₂). Cyclic voltammetry (CV), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were used to characterize the bioconjunction of the AuNPs-CNs with Mb. Experimental results demonstrate that the AuNPs-CNs hybrid material is more effective in facilitating electron transfer of the immobilized enzyme than CNs alone, which can be attributed to the unique nanostructure and larger surface area of the bioconjunction. The biosensor displayed good performance for the detection of H₂O₂ with a wide linear range from 0.28 μmol/L to 116.5 μmol/L and a detection limit of 0.12 μmol/L. The Michaelis-Menten constant K _M^app value was estimated to be 0.3 mmol/L. The resulting biosensor exhibited fast amperometric response, and good stability, reproducibility, and selectivity to H₂O₂. This article is published with open access at Springerlink.com     

有限单元法在地下工程围护结构传热中的应用

分析总结现有地下工程围护结构传热研究不足的基础上,对实际贴壁式和离壁式衬砌地下工程围护结构进行合理的物理数学简化,建立了热传递过程的数学模型.该数学模型中详细考察了不同的边界条件.有限单元法对复杂区域具有良好的适应性,论述了有限单元法在地下工程维护结构传热中的应用.     

Architecture engineering of hierarchically porous chitosan/vacuum-stripped graphene scaffold as bioanode for high performance microbial fuel cell

The bioanode is the defining feature of microbial fuel cell (MFC) technology and often limits its performance. In the current work, we report the engineering of a novel hierarchically porous architecture as an efficient bioanode, consisting of biocompatible chitosan and vacuum-stripped graphene (CHI/VSG). With the hierarchical pores and unique VSG, an optimized bioanode delivered a remarkable maximum power density of 1530 mW m(-2) in a mediator-less MFC, 78 times higher than a carbon cloth anode.     

氯化聚乙烯对氯丁橡胶与甲基丙烯酸甲酯接枝共聚反应的影响

研究了高氯氯化聚乙烯(HCPE)对氯丁橡胶与甲基丙烯酸甲酯接枝共聚及其反应产物的影响。结果表明,HCPE能加快聚合速率,提高转化率、接枝效率和接枝度。含HCPE的产物,含有较高分子量的级份,分子量分布较宽,树脂相的分布比较均匀,并具有较好的机械性能和较高的粘接强度。