Identification methods for anomalous stress region in coal roadways based on microseismic information and numerical simulation

It is believed that the microseismicity induced by mining effect and gas gradient disturbance stress is a precursor to the essential characteristics of roadway unstability. In order to effectively identify and evaluate the stability of coal roadways in the process of mine development and extraction, a microseismic monitoring system was deployed for the study of the stress evolution process, damage degree and distribution characteristics in the tailgate and headgate. The mine under study is the 62113 outburst working face of Xin Zhuangzi coalmine in Huainan mining area. The whole process of microfractures initiation,extension, interaction and coalescence mechanisms during the progressive failure processes of the coal rock within the delineated and typical event clusters were investigated by means of a two dimensional realistic failure process analysis code(RFPA2D-Flow). The results show that the microseismic events gradually create different-sized event clusters. The microseismicity of the tailgate is significantly higher than that of the headgate. The study indicates that the greater anomalous stress region matches the area where microfractures continuously develop and finally connect to each other and form a fissure zone.Due to the mine layout and stress concentration, the ruptured area is mainly located on the left shoulder of the tailgate roof. The potential anomalous stress region of the coal roadway obtained by numerical simulation is relatively in good agreement with the trend of spatial macro evolution of coal rock microfractures captured by the microseismic monitoring system. The research results can provide important basis for understanding instability failure mechanism of deep roadway and microseismic activity law in complex geologic conditions, and it ultimately can be used to guide the selection and optimization of reinforcement and protection scheme.     

人血清淀粉样蛋白A1原核表达及胶体金检测方法的建立

通过胶体金免疫层析技术建立一种特异、便捷、快速的SAA1定量检测新方法.利用大肠杆菌BL21(DE3)原核表达人血清淀粉样蛋白A1(SAA1),根据BL21(DE3)表达偏好性设计并合成SAA1蛋白基因片段,构建表达载体pET-28a-SAA1,采用CaCl2法制备BL21(DE3)感受态,热激转化法将pET-28a-SAA1转入到BL21(DE3).经表达条件优化,获得重组蛋白最佳诱导表达条件:温度30℃,时间6h,转速180rpm/min,培养基pH 7.0,IPTG浓度0.4mM,诱导表达后目的蛋白经SDS-PAGE电泳鉴定,Ni柱纯化、透析、浓缩从而获得浓度为8.09mg/ml,纯度为85%的SAA1.同时,结合胶体金标记技术,建立了SAA1胶体金免疫层析试纸检测方法,线性范围0.16~500μg/ml,最低检测限0.16μg/ml,该研究为临床体外诊断SAA1快速检测提供技术基础.     

金矿堆浸中废水治理的工艺研究

从低品位（0．5—3g／t）含金矿石中提取黄金会产生大量高体积质量（〉350mg／L）剧毒氰化物废水,为了减少含氰废水对人类健康和对环境造成的污染,有效地保护生态平衡,论述了含氰废水的4种治理工艺,即碱性氯化法、酸化法、自然净化法和二氧化硫．空气法的除氰原理、反应过程、工艺流程和治理效果,并分析了其优缺点、结合宁夏中卫金矿在实际生产中采用碱性氯化法治理含氰废水的试验和工艺研究,重点对碱性氯化法进行了分析．研究表明,该方法简捷、快速、安全、经济,易于掌握,治理效果好,完全达到中华人民共和国《污水综合排放标准GB8979-88》中的规定和环保要求．该方法较适宜在宁夏各矿山黄金生产中推广和应用．     

Catalytic activity of Au/Fe-PILC and Au/Fe-oxide catalysts for catalytic combustion of formaldehyde

Iron polymeric hydroxygroups pillared clays （Fe-PILC） were prepared by Na^＋-montmorillonite with iron pillaring agent. 2.01Au/Fe-PILC catalyst was obtained by deposited-precipitation （DP） method. 2.52Au/Fe-oxide catalyst was prepared by co-precipitation method. The catalytic activity of these catalysts was measured by catalytic combustion of formaldehyde. The catalyst of 2.01Au/Fe-PILC exhibits the high catalytic activity. The catalytic combustion reaction of formaldehyde proceeds at considerable rates at 20 ℃ and complete burn-off of formaldehyde is achieved at 120 ℃. The structure of catalysts, the valence state of gold and the size of gold particles were investigated by means of X-ray powder diffractometry, X-ray photoelectron spectroscopy and transmission electron microscopy. The results show that gold atoms with partially positive charge exist in the catalyst and play an important role in the catalytic activity. In addition, nano-sized, well-dispersed gold particles and good adsorption properties of support are necessary to obtain high activity Au catalysts for catalytic combustion of formaldehyde.     

纳米金丝电导量子效应

综述了纳米金丝电导量子效应的基本概念，介绍了金丝电导研究背景及现状，并从理论上分析了电导量子效应的机理。介绍了用STM和MCBJ等工具对纳米金丝的原子基链进行的研究。纳米金丝原子基链的电导是量子化的，量子电导受到包括电场、磁场、温度等各种因素的影响。在综述的基础之上，提出了该领域未解决的科学问题并指出了该领域未来的发展方向。     

用电生的Fe(Ⅱ)-EDTA络合物在Fe(Ⅲ)-EDTA-ClCH2COOH-NaOAc缓冲溶液中精密库仑滴定金

提出了在Fe(Ⅲ)-EDTA—ClCH2COOH—NaOAc缓冲溶液中利用电生Fe(Ⅱ)-ED-TA络合物精密库仑滴定Au的方法。采用电位法检测终点，测定范围在5．2～17．0mg Au时，相对平均误差和标准偏差≤0．03％。方法可用于纯金、金合金和首饰等材料中Au含量的精密分析，选择性很好。讨论了电生Fe(Ⅱ)-EDTA络合物作库仑滴定剂的理论基础，获得了有益的结论。     

Ar^39／Ar^40 dating of three typical gold deposits in southern Qinling and its implication

1　ＩＮＴＲＯＤＵＣＴＩＯＮＱｉｎｌｉｎｇｏｒｏｇｅｎｉｃｂｅｌｔａｂｕｔｓＮｏｒｔｈＣｈｉｎａ ｐｌａｔ ｆｏｒｍｗｉｔｈＳｈａｎｇｚｈｏｕ ＤａｎｆｅｎｇｇｅｏｓｕｔｕｒｅｉｎｔｈｅｎｏｒｔｈａｎｄｎｅｉｇｈｂｏｒｓＹａｎｇｔｚｅ ｐｌａｔｆｏｒｍｗｉｔｈ     

Effects of gold plating on the resistance to high temperature discoloration of the cavity for ceramic packages

The effects of thickness and types of gold plating on the resistance to high temperature discoloration of gold plating on cavity surface of ceramic package were investigated. It was found that the thicker gold plating, the less discoloration degree for ceramic packages. Non-cyanide gold plating performed better resistance to high-temperature aging than cyanide gold plating. The relationship between the gold plating thickness and the amount of diffused Ni to the gold plating of ceramic packages with Au/Ni and Au/Ni-Co platings after heating at 420℃for 15 min was also studied. When the gold plating thickness reach 2.0 μm and 1.6 μm for Au/Ni and Au/Ni-Co plating systems, respectively, no discoloration was observed on the gold plating surface of cavity, and the corresponding diffused Ni amounts (mass fraction) are 1.0% and 0.4%, while the diffused Co to the gold plating is 0.04%.     

晋东北金矿床石英流体包裹体与找矿

晋东北各种类型金矿中都广泛发育热液型石英脉，与矿化有关的石英流体包裹体的特征反映了不同的矿床类型。对该区石英脉型、蚀变岩型及磁铁石英岩型金矿床的研究表明，石英中流体包裹体的成分、温度和红外吸收光谱等特征可以作为划分矿床类型和作为金矿找矿评价的标志     

XPS characteristics of sulfur of bio-oxidized arsenic-bearing gold concentrate and changes of surface nature of bio-oxidation residue

During bio-oxidation of sulfides, the chemical state change of sulfur is a complex and key factor. It is not only an indicator of the extent and intensity of the bio-oxidation, but also controls the property of bio-leaching medium and the period of oxidation. The chemical state of sulfur in sulfides oxidized by leaching bacteria was studied with XPS. Sulfide minerals in the arsenic-bearing gold concentrate consist of pyrite, arsenopyrite, chalcopyrite, galena, sphalerite and so on. In order to probe the pattern of the chemical state change of sulfur in the bio-oxidation residue of arsenic-bearing gold concentrate, the structure of the grains, and the surface nature of the residue, XPS test was carried out through different sputtering duration. The study of XPS clearly shows that: sulfides is progressively oxidized from the surface of minerals to the core by leaching bacteria; the chemical valence of sulfur changes from S^2- or [S2]^2- to [SO4]^2- ; sulfur in the core is in a reduction state, S^2- or [S2]^2- , but exists in an oxidation state S^6 on the surface; due to the chemical state change of sulfur, mineral phase of the bio-oxidation residue is also changed(sulfides inside, while sulfates outside); the layered structure is found in the grains of the bio-oxidation residue.