Matched Filter Based Spectrum Sensing When Primary User Has Multiple Power Levels

In this paper,we investigate the matched filter based spectrum sensing in a more reasonable cognitive radio(CR) scenario when the primary user(PU) has more than one transmit power levels,as regulated in most standards,i.e.,IEEE 802.11 Series,GSM,LTE,LTE-A,etc.This new multiple primary transmit power(MPTP) scenario is specialized by two different targets:detecting the presence of PU and identifying the power level.Compared to the traditional binary sensing where only the presence of PU is checked,SU may attain more information about the primary network(making CR more "intelligent") and design the subsequent optimization strategy.The key technology is the multiple hypothesis testing as opposed to the traditional binary hypothesis testing.We discuss two situations under whether the channel phase is known or not,and we derive the closed form solutions for decision regions and several performance metrics,from which some interesting phenomenons are observed and the related discussions are presented.Numerical examples are provided to corroborate the proposed studies.     

某矿山地压分布规律的研究

通过现场实测，研究了某矿山采空区矿柱中的应力分布规律，并据此对空区上方的地压和空区矿柱的稳定状况和安全性进行了评价，为该矿今后的安全生产、矿柱加固和设计参数的调整提供了可靠的科学保证。     

大倾角特厚煤层综放支架防倒防滑安全保障技术

基于古山矿三井大倾角特厚煤层的地质条件,围绕综放面装备防倒防滑的技术难点,从液压支架结构、工作面布置方式、放煤工艺、工作面管理等方面进行了研究,并制定了安全保障技术。主要保障技术:端头3架组成锚固站,作为工作面支架纵向稳定性的基础;支架安装高强度双侧可调活动侧护板,并设置底座调节机构;工作面采用"倾斜-圆弧过渡-水平"的布置方式,减小工作面机头坡度,保证机头支架的稳定性;通过放煤工艺优化模拟,确定采用"单向割煤,二采一放"的放煤方式,以控制支架下滑;沿着工作面倾斜方向,工作面上部由上而下放煤以保持支架的稳定性;工作面其他地段由下而上放煤有利于提高顶煤回收率。工业性试验表明,综放面设备稳定性良好,顶煤回收率达80%,实现了大倾角综放面的安全高效回采,对于类似地质条件的综放装备防倒防滑具有借鉴意义。     

DetNet电子雷管产品评介

文中对DetNet公司几种电子雷管起爆系统及其应用情况进行了介绍和评述，分析了我国电：于雷管发展现状。指出：加快电子雷管的技术研究和工程化应用，将有利于解决我国延期电雷管只能采用固定时差间隔、精度较差和质量不稳定的难题。     

典型烟煤高温焦炭孔隙结构及其活性的研究

本文通过高温试验和扫描电镜分析,研究三种典型烟煤在800～1600℃条件下,其焦炭的膨胀性、流动性、软化现象、孔隙结构及其活性。结果表明,低变质弱粘结煤高温焦炭的孔隙最发育,活性最好;中变质肥煤次之,高变质瘦煤最差。低变质弱粘结煤在高温下可产生大量纳米级碳粒。     

对岩体内摩擦角取值的商榷

通过计算机模拟节理岩体加载试验的结果，对岩体内摩擦用取值的范围作了探讨。     

Engineering practice of reducing ground subsidence by grouting into overburden bed-separated and similar model experiment

The subsidence prediction theory under the condition of grouting into bedseparated was developed. Reducing ground subsidence by grouting was carried out on eight fully-mechanized top-coal caving faces, by using the continuous grouting in multiple-layer to obtain experiment results of reducing subsidence under fully mining. The similar material model that can be dismantled under the condition of constant temperature and constant humidity was developed. The model was used to simulate the evolution of overburden bed-separated under such constraints of temperature and humidity, at the same time, and to test the hardening process of similar materials.     

炸药水下爆炸引起地面振动的研究

文中简要介绍了爆破振动速度衰减规律及安全判据，分析了爆破振动频率的特性，用RDX在实验室条件下进行了水下爆炸测试，其目的是研究炸药在水中爆炸时所引起地面振动及振动频率等问题。     

本质安全便携式爆破网路检测仪设计

作者针对煤矿井下爆破工作者现场检测电雷管和电爆网路可靠性的需求,采用MSP430低功耗单片机设计的一款本安型便携式爆破网路检测仪,该仪器具有体积小、功耗低,便于携带、使用简单方便等特点。文中介绍了该仪器的硬件组成、本质安全性电路设计及整机低功耗的实现。     

嵌段共聚物及其在制备高比表面积介孔材料中的应用

介孔材料因具有比表面积大、孔径分布均一及结构有序的特性,被广泛应用在催化剂载体、吸附材料及分离介质等领域。本文介绍了嵌段共聚物的结构特征及其在选择性溶剂中的自组装行为,综述了以嵌段共聚物为模板剂,采用溶胶-凝胶(sol gel)法制备高比表面积、高热稳定性介孔材料的控制过程,影响因素及制备非硅体系介孔材料的技术特性。