急倾斜煤层采空区结构特征GPR探测

急倾斜煤岩体结构和地质缺陷具有隐蔽性。历史性无序开采形成的采空区分布的不规则性严重影响安全开采。以神新小红沟煤矿急倾斜煤层开采区域空区分布规律预测与参数确定为目标。通过理论分析、GPR地面与地下立体联合探测,分析了+522水平B3和B6开采扰动范围内采空区结构特征。+522水平距五一煤矿巷道垂直距离约为35.0～35.5 m.B3巷1 214～1 232m范围内空区覆岩破坏严重,多处出现破碎区。空区下部近似椭圆,上部似半椭球体结构,且空区已联通。1 232～1 250 m范围空区及覆岩破坏严重,局部区域积水量大,为现场开采设计与灾害防治提供科学依据。     

不合理装修对结构受力性能的影响

针对当前建筑装修中常见的不合理的装修现象,如拆墙扩洞、开槽布线、封闭阳台、楼面加载等,分析了出现的原因和对建筑结构整体性及抗震性产生的不利影响,提出了预防不合理装修的几点措施。     

Sedimentation processes and sedimentary characteristics of tidal bores along the north bank of the Qiantang Estuary

A tidal bore is a unique Earth surface process, characterized by its highly destructive energy, predictable periodicities and magni-tudes, and the production of characteristic sedimentary features. Tidal bores and associated rapid flood flows are highly turbulent flows of the upper-flow regime with a velocity over several meters per second. Reynolds (Re) and Froude (Fr) numbers, respectively, are larger than 104 and 1.0, making them significantly different from regular tidal flows but analogous to turbidity currents. Until now, understanding of tidal-bore depositional processes and products has been limited because of the difficulty and hazards involved with gauging tidal bores directly. The Qiantang bore is known as the largest breaking bore in the world. Field surveys were carried out in May 2010, along the north bank of the Qiantang Estuary to observe the occurrence of peak bores, including regular observations of current, water level and turbidity at the main channel. Several short cores were sampled on the intertidal flats to study the characteristic sedimentary features of tidal bores. Hydrodynamic and sedimentological studies show that the processes of sediment resuspension, transport and deposition are controlled primarily by the tidal bores, and the subsequent abruptly accelerated and decelerated flood flows, which only account for one tenth of each semidiurnal tidal cycle in the estuary. Tidal-bore deposits are generally poorly sorted because of rapid sedimentation after highly mixed suspension by intense turbulence. This behavior is characteristic of the absence of tractive-current depositional components in a C-M diagram. It also goes along with well-developed massive bedding, graded bedding, basal erosion structures, convolute bedding and dewatering structures. Together, these sedimentary features can constitute fingerprinting of turbidites, widely distributed in the deep-water environment. However, a tidal bore is triggered by intensely deformed tidal waves propagating into a shallow-water environment, which returns to regular tidal flows rapidly after the passage of the bore head. The tidal-bore deposits are usually bounded by the intertidal-flat deposits with typical tidal beddings at the top and on both flanks. The difference between tidal-bore deposits (TBD) and tidal sandy/muddy deposits (TSD/TMD) is evident not only in sedimentary structures, but also in the grain-size composition. They can be clearly distinguished in grain-size bivariate plots, typically the plot of mean grain size vs. standard deviation (or sorting). Some trend variations generally exist in mean grain size with TBD>TSD>TMD, sorting with TMD>TBD>TSD (larger value indicating poorer sorting), and both skewness and kurtosis with TSD>TBD>TMD. These findings will undoubtedly shed new light on our understanding of tidal-bore sedimentology, ancient tidal-bore sedimentary facies and environments, and related oil-and-gas field prospecting.     

从人本思想的发展看先秦史书编撰的变化

人本思想的演进和发展是中国社会发展中的重要问题。作为时代的缩影，各代史书的编撰中必然渗透了当时人本思想的流变，暗含撰史者对当世的理解与阐释。先秦是中国古代人本思想发展的重要时期，以人本思想发展为线索反观该时段史书编撰的变化，能够更加深入地体会中国古代史家独特的历史见解和以人为重的史学传统。     

水合鸢尾异黄酮磺化物[K（H2O）]（C17H13O6SO3）的合成及晶体结构

目的 合成一种新的水溶性水合鸢尾异黄酮磺化衍生物[K(H2O)](C17H13O6SO3),并确定其分子结构.方法 在60 ℃条件下用浓H2SO4磺化30 min,得到尼泊尔鸢尾异黄酮磺化物,并用体积比为 1/1 的乙醇-水溶液培养单晶,采用X-射线四圆衍射、IR和元素分析等方法表征其结构.结果 和结论将尼泊尔鸢尾异黄酮在60 ℃用浓硫酸磺化,高选择性地在底物B环的3′位引入一个磺酸基,合成了水溶性尼泊尔鸢尾异黄酮衍生物,产率为82%.该合成方法简单,反应条件温和,选择性高,产物容易分离,且产率较高,是合成标题化合物一种理想的方法.X-射线晶体结构表明该化合物属于单斜晶系,空间群P21m,晶胞参数a=0.835(4) nm,b=0.728(3) nm,c=3.000(14) nm,β = 96.09(7)°,V=1.814(15) nm3,Dc=1.650 g·cm-3,Z=4.在化合物的晶体结构中, 相邻的钾离子之间被O6,O7和O8桥链形成聚八面钾离子链.此外,化合物中还存在多个氢键,这使化合物自组装成一个三维网格结构的超分子.     

基于改进遗传算法的桁架结构优化

桁架是一种广泛应用于工程领域的结构形式,对其结构优化有重要的意义.文章提出了随种群的进化而动态变化的自适应交叉算子和变异算子,以提高算法的优化效率及增强收敛性;引入了精英保留策略,以克服各代种群最佳个体未能保护的缺点.建立以最小化结构总重量为目标函数的桁架优化数学模型,并应用改进的遗传算法对桁架结构进行优化求解.通过实例验证了所建模型以及对算法改进的有效性和实用性.     

从皇权依附到集团依附——论汉末士风对政治结构的影响

＂人的觉醒＂是汉末士风变化的基本特点。然而,汉末＂人的觉醒＂,并未完全回归到先秦之士＂志于道＂的政治超越的精神状态,而带有强烈的政治依附性,只不过这种依附由汉鼎盛时期所表现出的强烈的皇权依附逐步向集团依附转化。这种士风的变化,始于党锢集团对皇权依附意识的解构,从而形成汉灵帝中平元年以后至建安时期皇权依附意识与集团依附意识的互动,正是这两种意识的互动深刻地影响了汉末政治结构的变化———皇权逐渐傀儡化,皇权专制逐渐让位于集团专制,并最终导致旧皇权的消亡与新皇权的产生。     

平面梁单元的温度应力

介绍了能量原理在结构矩阵分析方面的原理及应用。以虚位移原理为理论依据,采用MATLAB符号运算的方法,分析了平面梁单元在荷载及温度变化影响下的单元刚度矩阵。计算表明:该方法在形成和求解由平面梁单元组成的工程结构时,具有较大的速度优势及良好的程序可读性。     

基于网络的教学资源编辑平台功能结构设计

根据目前教学资源发展需求,提出一种基于网络的教学资源编辑平台,并对其结构功能进行设计。     

某砖混结构阳台挑梁加固方法及案例分析

针对某多层砖混结构阳台挑梁混凝土强度偏低,通过几种加固方案的比较采用增加钢拉杆和粘贴碳纤维布的方法进行加固处理,加固后进行荷载试验,试验表明构件满足承载力使用要求,投入使用多年,使用状况良好,表明所采用的加固方案有效,可供类似工程加固设计参考.