煤样粒径对煤低温氧化影响的实验研究

基于测试耗氧速率和氧化动力学参数研究煤样粒径对煤低温氧化的影响。利用煤低温氧化测试系统,测算在供应气体流量、氧含量等给定条件下四类不同粒径范围煤样升温氧化耗氧速率,同时依据基于耗氧量建立的数学模型来测算煤低温氧化时不同粒径煤样活化能和指前因子等动力学参数,结果表明不同粒径煤样低温氧化耗氧速率变化分为缓慢耗氧、浅度耗氧和深度耗氧等三个阶段,在实验条件下煤样粒径小于0．198mm的煤样更适合煤低温氧化。     

Ag_2Se/Se/SiO_2纳米复合物的制备及其光电性质

通过两步法成功合成了Ag2Se/Se/SiO2纳米复合物。首先采用Na2SiO3和Na2SeSO3为反应物,制得纳米Se/SiO2前驱物,然后将前驱物与AgNO3反应制得产物。讨论了产物的形成机理,利用TEM、XRD、UV-vis、FT-IR、LRS、PL等方法对产物进行了表征,并对产物的电化学和电致发光特性进行了研究。结果表明,产物有一定的电化学活性,并有较好的电致发光行为。     

基于地下水流数值模拟的反求参数方法研究

在建立GMS地下水流数值模拟模型的基础上,通过人工调参、PES process分区调参及PES process导点法调参三种方法反求水文地质参数,并对三种调参方法的特点和结果进行了对比分析,发现在人工调参基础上的PES process分区调参的效率和精度较高,模拟结果比较符合实际的水文地质条件。实例应用结果同时表明,三种反求水文地质参数方法都具有较好的实用性。     

Propagation law of shock waves and gas flow in cross roadway caused by coal and gas outburst

In order to study the propagation law of shock waves and gas flow during coal and gas outburst, we analyzed the formation process of outburst shock waves and gas flow and established the numerical simulation models of the roadways with 45° intersection and 135° intersection to simulate the propagation of outburst gas flow and the process of gas transport. Based on the analysis of the simulation results, we obtained the qualitative and quantitative conclusions on the characteristics and patterns of propagation and attenuation of outburst shock waves and gas flow. With the experimental models, we investigated the outburst shock waves and gas flow in the roadways with the similar structures to the simulated ones. According to the simulation results, when the angle between the driving roadway and the adjacent roadway increased, the sudden pressure variation range in adjacent roadway and the influencing scope of gas flow increased and the sudden pressure variation duration decreased. The intersection between the driving roadway and the adjacent roadway has no effect on airflow reversal induced by the shock waves and gas flow.     

A damage-based constitutive model for rock under impacting load

Using the Splitting Hopkinson Pressure Bar (SHPB) experimental system, investigations were made into the dynamic mechanical performances of underground soft rocks. The experiments proved that the measured stress–strain curves display the characteristics of plastic deformation. By making use of a revised overstress constitutive formula for the stress model and by taking into account that the strain rate and strain are a function of 1 − E(t)/E₀, a revised overstress constitutive formula for the stress model was simplified by applying dimensional analysis and consequently, a simplified overstress formula was obtained for the stress model. Then, by taking into consideration the effects of damage under a dynamic load on the dynamic loading strength of the rock, the continuous damage theory and the statistical strength theory were introduced into the development of the simplified overstress constitutive formula for the stress model. Hence, a damage-based constitutive formula for an overstress model, which can be appropriately applied to the analysis of full dynamic stress–strain curves, was developed. By using the simplified damage-based constitutive formula for an overstress model, the actually measured curves are fitted, indicating that the fitting curves and those actually measured are in good agreement.     

环 上线性码的对称重量计数器

定义了环 （其中, ）上线性码的对称重量计数器的概念,利用离散的Hadamard变换,确定了该环上线性码与其对偶码之间关于对称重量计数器的MacWilliams恒等式．最后,利用对称重量计数器,进一步建立了环 上线性码关于Hamming重量计数器和Lee重量计数器的MacWilliams恒等式．     

基于VBA和AutoCAD的瓦斯抽采钻孔设计与反演系统

针对当前瓦斯抽采钻孔设计与反演主要依靠人工计算,费时费力且容易出错的缺点,基于VB6.0编译环境和AutoCAD 2010绘图平台,设计了一套能够与CAD动态交互的瓦斯抽采钻孔设计与反演系统。实现了基于AutoCAD巷道图的参数化快速建模,通过动态交互减少了大量的测量和计算,达到精确、快速进行钻孔设计与反演的目的。实践证明,该系统可有效提高钻孔设计与反演效率,大幅减少设计与反演过程中的人为错误。     

封闭型地质构造诱发煤与瓦斯突出的力学特性模拟试验

运用自行研发的大型三维煤与瓦斯突出模拟试验装置,模拟研究了石门揭露前方封闭型地质构造破坏区过程中围岩应力和瓦斯压力的分布及变化规律.结果表明:受构造应力影响,封闭型地质构造破坏区围岩初始应力较高,为正常区域初始应力的1.5～1.7倍;石门巷道推进过程中,封闭型地质构造破坏区围岩应力进一步增加,可达正常区域煤岩初始应力的2倍以上;封闭型地质构造破坏区临揭露前,仍然保持着较高的围岩应力和瓦斯压力,形成异常高的应力梯度和瓦斯压力梯度,为煤与瓦斯突出的发生提供了有利条件.     

水热法钛酸钠的制备与结构研究

以自制Ti(OH)4、TiO2和NaOH为前驱物,经过超声混合后,通过水热反应法合成了不同Ti/Na比的钛酸钠光催化剂,并采用X-射线粉末衍射(XRD)和紫外-可见漫反射光谱(UV-vis-DRS)分别对合成的样品进行了晶型形貌和光吸收特性的表征并对其进行比较。实验结果表明:由于是水热反应,样品晶型较为复杂,可能在合成过程中形成了水合阳离子,导致它的晶型受到一定的影响。同时水热反应法合成的样品(Na2Ti3O7)对光的吸收带位置在337nm左右。     

岩石材料动态断裂韧性的实验研究

为了研究岩石类材料的动态力学性能及动态破坏机理,防止出现岩石爆裂造成灾难性破坏,根据中心裂纹圆盘试件断裂韧性测试方法和分离式霍普金森压杆的基本原理,在SHPB装置上测试了花岗岩的动态断裂韧性。对测试结果按照SHPB基本原理进行处理,以试件两端平均载荷带入准静态公式得到动态断裂韧性。处理结果表明,用试件两端平均载荷获得岩石动态断裂韧性的实验方法有效的;花岗岩的动态断裂韧性具有加载速率相关性,随着加载速率的增加断裂韧性增大。