Neck-controlled sensitivity study on nano-grain SnO_2 gas sensors

1. Introduction SnO2 is an n-type semiconductor with rutile crystal structure and with a wide band gap of about 3.6 eV. SnO2 has a wide range of applications as photo-detectors, heat mirrors, transparent electrodes for solar cells, conductive filler, thick resistors, catalysts and gas sensors. One of the most important applications of SnO2 lies in gas sensors [1]. SnO2 gas sensors have been attracting much attention [2-5] because of their many advantages over current technologies for detect…     

《非常规油气地质学》课程教学改革探索

作为近十年来油气勘探的热点,关于非常规油气地质的课程在各地质类高校广泛开设。现行的非常规油气地质教学体系大多以油气资源类型展开。该教学体系利于讲、便于扩展,但系统性不足、内容交叉重叠。针对这一不足,结合近年来《石油地质学》的教学科研进展,对《非常规油气地质学》课程体系开展了梳理,教学内容和重点进行了厘定。以非常规油气资源独特的运聚动力学特点为基础,设立非常规油气聚集理论部分作为总论;各论部分沿袭原体系中类型为主导,突出了各非常规油气资源类型形成条件与聚集规律的论述,增加了不同类型非常规油气资源量的评价与计算方法论。经过教学体系的调整,总论部分的讲授将增强非常规油气聚集的理论特质,资源量评价与计算的内容则增强了该课程的实践性,与此同时,最大程度保留了原体系中不同非常规油气资源类型相对独立的特性,便于针对性的学习。     

焊瓶钢板缺陷分析及改进措施

文章通过检验废品,分析生产工艺缺陷,找出HP295成瓶率低的原因,并提出相应的改进措施.     

青蒿素的热稳定行为及气相色谱分析

以气相色谱法研究了青蒿素的热稳定性、分解行为以及气相色谱分析方法.在色谱图上发现,青蒿素热分解有两个主产物,经推测可能为分解或重排产物.还发现前期流出的产物与青蒿素浓度有线性关系,据此可对青蒿素含量进行分析.     

电镀工业氮氧化物废气治理技术

本介绍了氮氧化物废气的来源、危害以及电镀工业氮氧化物排放特点，着重介绍了治理氮氧化物废气的几种方法，并对吸收液和吸收塔进行了深入的探讨和研究。结果表明，使用碱性溶液作为作为吸收液．使用旋流板塔作为吸收设备是治理电镀工业氮氧化物废气的一种较为成熟、可靠的技术。     

非理想气体的卡诺循环

把范德瓦尔斯气体和昂尼斯气体作为工作物质，计算其卡诺循环的效率，与理想气体卡诺循环的效率相同，进一步说明卡诺定理的正确性．     

石油与天然气工程专业工程硕士培养的实践与体会

本文简要介绍了笔者参与中国地质大学(北京)和大庆油田联合培养石油与天然气工程专业工程硕士研究生过程中的一些有益的做法和措施,并就今后的工作重点做了进一步的思考。     

Numerical calculation for gas and strata movement law caused by protection layer mining

According to the problem during mining coal seam with high gas and its control, the theory numerical calculation of gas and strata movement law caused by protection layer mining was studied, with the background of Snake Mountain coal mine. First of all, the basic principle of fluid (gas)-solid coupling was briefly described, and a three dimensional model was established by FLAC software. Secondly, the calculation parameters of fluid-solid coupling were obtained based on the measured data, and the numerical calculation of sublevel mining was carried out in turn. Lastly, initial stress state, gas movement law, deformation law of pore pressure and movement characteristics of rock strata were studied, respectively. The results show that the gas and pressure were greatly reduced with the advance of 4 coal seam working surface, as well as the constant increase of area of goaf. Facilitating gas and the stress were gradually penetrated and released to goaf during the whole process of mining. The gas pressure, the aggregation degree and the surrounding rock pressure of the 1 coal seam and the 3 coal seam were greatly reduced.     

某矿6.12煤与瓦斯突出事故的处理与分析

煤与瓦斯突出是煤矿井下短时间内发生的一种特殊动力现象，它是煤矿一个重大灾害，针对一起掘进工作面煤与瓦斯突出事故，介绍了事故处理方案的从确定到实施的简要过程，同时分析事故发生原因，并提出预防对策；根据这起在78小时后成功抢险出一名遇险人员的事故处理，首次提出了在突出发生后人员生存条件评估和如何尽可能确定遇险者分布位置，为以后类似事故处理工作提供了借鉴。     

n维谐振子系统的状态函数--高温弱简并和经典情况下的比较与分析

推导出了能谱为ε=^n∑i=1 Pi^2/2m＋＋1/2mi^2ri^2的n维经典谐振子的态密度，由于处于n维简谐势阱中的粒子可以看作n维谐振子，进而求出了服从玻尔兹曼分布、费米分布、玻色分布的n维简谐势阱中的粒子的状态方程及各热力学函数。