矿业权实地核查数据库的建设与应用

数据库建设是整个矿业权实地核查工作的重要成果体现。本文以山西省为例,介绍了矿业权实地核查工作的属性数据库、空间数据库、数据成果综合、数据汇总与系统建设等主要内容。针对生产实践中存在的问题,设计了矿业权数据建库专用软件,解决了数据库建设的相关课题,为加强矿政管理,获得全面矿业权基本数据,实现新一轮矿业权换证提供依据。     

阳泉矿区综放工作面瓦斯综合治理探讨

充分发挥综采放顶煤开采的技术优势,治理综放工作面瓦斯尤为重要。在介绍阳泉矿区15号煤层及邻近煤岩层瓦斯赋存基础上,分析了综放工作面瓦斯来源和特征,提出了不同条件下瓦斯治理方法及治理措施,并对其治理效果进行了分析。实践应用表明,走向高抽巷与内错尾巷共用系统排放工作面瓦斯,效果最为显著。     

Improved properties of PTFE composites filled with glass fiber modified by sol–gel method

PTFE/GF(glass fiber) composites are widely applied in high-frequency printed circuit board (PCB) substrate materials due to the excellent dielectric properties of PTFE and the low thermal expansion coefficient of GF. However, the poor interface compatibility between PTFE and GF affects the performance of the composite substrates. In this study, tetraethyl orthosilicate (TEOS) was used as the silicon source, and polydimethylsiloxane (PDMS) was the organic precursor to modify the surface of GF through the sol–gel method to promote the interface compatibility of GF and PTFE. The modified GF noted T-GF was filled in PTFE to prepare PTFE/T-GF composites. SEM, FTIR, XPS, and contact angle confirmed that organic–inorganic hybrids were successfully loaded on GF's surface. Moreover, compared with PTFE/GF and the conventional coupling agent modified GF filled PTFE composites, the PTFE/T-GF exhibited improved dielectric constant (2.305), decreased dielectric loss (9.08E^?4), higher bending strength (21.45 MPa) and bending modulus (522 MPa), better thermal conductivity (0.268 W/m*K) and lower CTE (70 ppm/°C), making it has promising application as the substrate materials for high frequency PCB.

     

二维 Volterra-Fredholm 积分方程数值算法研究及收敛性分析

针对一类二维非线性Volterra-Fredholm积分方程,提出利用二维Block-Pulse函数为基函数进行数值求解。首先,引入Block-Pulse函数的定义及基函数的向量表示形式;其次,根据二维Block-Pulse函数的不相交性和正交性推导了基向量的积分算子矩阵和乘积算子矩阵;然后,基于该算子矩阵将待求问题转化为一系列向量的乘积形式,利用配点法离散未知变量获得原问题的数值解;最后,通过两个具体的数值算例对所提算法的可行性和收敛性进行了验证。     

Navier-Stokes/Darcy 模型的 BDF2 模块化梯度散度稳定格式的数值分析

Navier-Stokes/Darcy 方程可用来模拟河流中的污染物对地下水的污染问题,以及血液在血管及器官间的渗透问题等,由于其在实际中的广泛应用,对其数值方法的研究受到广泛关注。提出了求解Navier-Stokes/Darcy方程的BDF2模块化梯度散度稳定数值格式,这种格式通过增加稳定化项,提高了解的有效性和精确性,在保留梯度散度稳定格式优点的同时,可以有效的避免大的稳定化参数对解的非正常影响,给出了格式的稳定性和误差分析。最后,通过数值算例验证了理论分析的正确性。     

The bio-activation of pozzolanic activity of circulating fluidized-bed fly ash by Paenibacilllus mucilaginosus

The present investigation reports an eco-friendly biotechnology applying Paenibacilllus mucilaginosus (P.m), a silicate solubilizing bacteria, to activate pozzolanic activity of CFA. The results show SiO₂ and Al₂O₃ dissolution rate of CFA treated by P.m and its Ca²⁺ absorption capacity in saturated Ca(OH)₂ solutions are increased compared to raw CFA indicating that pozzolanic reactivity of CFA is improved by P.m. One reason is destruction of the anhydrite coating layer of CFA particles surface through P.m erosion. Another reason is promotion of SiO₂ dissolution caused by deformation and destruction of Si-O-Si (Al) bonds by P.m. Carbonic anhydrase activity of P.m is one of the main factors involved in dissolution of SiO₂, which also induces CaCO₃ mineralization. The hardening characteristics and hydration products of CFA-15% lime system with different content of P.m further confirm the effects of P.m on pozzolanic activity of CFA. 40% P.m incorporation is conducive to promote CFA hydration, ettringite earlier formation and bio-mineralization, thereby improving the mechanical properties of hardened mortar. Incorporation of 40% P.m in cement blended with CFA results in that CFA content is increased by 5–20% and the 28d strength improved by 11.5–23.9 MPa. This is the first report of microbial activation of CFA pozzolanic activity.     

一种基于动态均分的最大信息系数改进算法

针对最大信息系数(maximal information coefficient, MIC)算法计算时间复杂度较高的问题,提出一种基于动态均分的最大信息系数(dynamic equpartition of maximal information coefficient, DE-MIC)改进算法,利用动态均分对两变量在网格中的散点图进行不断迭代寻优,通过对获得的互信息进行正则化得到最优的DE-MIC值,同时利用标准的可移植操作系统接口(portable operating system interface of UNIX, POSIX)对数据集进行多线程计算,使算法在大规模数据集上的计算效率更高。经过在多个数据集上与快速最大信息系数算法(rapid computation of the maximal information coefficient, RapidMIC)比较, DE-MIC算法在保持原有最大信息系数算法普适性和均匀性的前提下,计算速度更快且效率更佳。     

白杨素减轻人脐静脉内皮细胞的氧化应激损伤

目的: 观察白杨素对人脐静脉内皮细胞（human umbilical vein endothelial cells,HUVEC）氧化应激损伤的保护作用。方法: 常规培养HUVEC细胞,分为5组：对照组,不加任何干预;H₂O₂组,用400 μmol/L过氧化氢处理2 h;白杨素高、中、低剂量组,提前用100、50、25 μmol/L的白杨素孵育12 h,然后用400 μmol/L过氧化氢处理2 h。处理结束后,用MTT法检测活细胞数目,并检测乳酸脱氢酶（LDH）的漏出。收集细胞上清液及细胞裂解液,检测NO、丙二醛（MDA）产量及内皮型一氧化氮合酶（eNOS）、超氧化物歧化酶（SOD）活性。用荧光染料DCEF-DA染色后,酶标仪检测活性氧（ROS）的产量。用荧光定量RT-PCR的方法检测黏附分子的表达。结果: 过氧化氢导致内皮细胞活细胞数目减少,LDH漏出增多,MDA、ROS产生增多,SOD活性下降,黏附分子表达增多,内皮细胞NO产生减少,eNOS活性下降。提前用白杨素预孵,可以增加细胞存活率,减轻氧化应激损伤,减少黏附分子的表达,eNOS蛋白活性增加,细胞NO的产量增加。结论: 白杨素可以减轻HUVEC的氧化应激损伤,减少黏附分子的表达,增加细胞NO的合成能力。     

基于突变理论电网企业信息安全风险管理模型研究

当代信息技术的快速发展使得电网企业面临着更为错综复杂的信息安全威胁,信息安全风险管理的作用也显得更加重要。因此,结合电网企业的特性,针对其信息安全风险管理进行了深入的研究与分析。首先,结合电网企业内外部信息环境的特点,对信息安全的风险进行了科学合理的归类识别;其次,首次结合突变理论构建信息安全风险评估模型,并结合其风险评估的结果设定阈值制定了风险应对的措施;此外,为增加电网企业信息安全的稳定性和可靠性,提出了多维度和多层次的风险防范措施;最后,通过将其方法应用到电网企业信息安全风险管理的实例验证了该方法的有效性和合理性。