内蒙古自治区内国家级自然保护区的有效管理分析

以内蒙古自治区内22个国家级自然保护区管理状况的评估结果为基础,从评估赋分表所涉及的10项评估指标入手,分析内蒙古自治区内国家级自然保护区管理活动的整体特征、区域差异和自然保护区有效管理的影响因素。结果表明,内蒙古自治区内国家级自然保护区管理评估平均得分为79分,整体处于良的等级,仍有较大的提升空间;自治区东部地区的自然保护区管理水平略高于西部地区,但两者之间差异未达显著水平。加强日常管护是提升内蒙古自治区内国家级自然保护区管理水平的首要任务,自然保护区的能力建设、机构设置和人员配置、保护对象动态变化、规划制定与执行和基础设施建设等因素对自然保护区的有效管理有显著影响。     

Estimating animal densities and home range in regions with irregular boundaries and holes: A lattice-based alternative to the kernel density estimator

Density estimates based on point processes are often restrained to regions with irregular boundaries or holes. We propose a density estimator, the lattice-based density estimator, which produces reasonable density estimates under these circumstances. The estimation process starts with overlaying the region with nodes, linking these together in a lattice and then computing the density of random walks of length k on the lattice. We use an approximation to the unbiased crossvalidation criterion to find the optimal walk length k. The technique is illustrated using walleye (Sander vitreus) radiotelemetry relocations in Lake Monroe, Indiana. We also use simulation to compare the technique to the traditional kernel density estimate in the situation where there are no significant boundary effects.     

土岩界面地震波能量传递与耗散特性研究——以汶川8.0级地震为例

以汶川8.0级地震为例,应用应力波在弹性介质界面能量分配与反射和透射系数之间的相关性,得出地震波在不同介质中滞留能量的耗散比与介质波阻抗比和上层介质能量衰减比之间的关系。通过离散数值计算发现当能量衰减比一定时,两种介质的波阻抗比在某一特定值时上层介质滞留能量耗散比达到最大,该值随着能量衰减比的增大而增大。这一结论对地震山区的"剥皮型"滑坡提供了一种全新的解释,并得到了路堤工程宏观震害与面波测试资料的验证。     

前期有效降雨对滑坡启动影响分析

降雨是诱发边坡失稳破坏的主要原因。以坡地水文模型为基础,结合无限边坡稳定计算模型,研究降雨条件下边坡启动的临界降雨条件。以都江堰市为研究区域,研究前期降雨、边坡体地下水位和渗流时间的关系,再结合滑坡启动的临界降雨模型,定量分析前期有效降雨对滑坡启动的影响。     

免疫粒子群优化在波阻抗反演中的应用

针对标准粒子群优化(PSO)算法易出现早熟而陷入局部最优以及进化后期收敛速度慢等缺陷,引入免疫系统的免疫记忆和抗体浓度选择机制,构造了基于免疫机制的粒子群优化(IPSO)算法,并将其应用到波阻抗反演问题中。免疫记忆能够保留高适应度个体,抗体浓度选择机制进一步保证了粒子的多样性,从而能较好地避免早熟收敛,提高算法的全局搜索能力。对理论模型试算表明,IPSO算法在进行波阻抗反演时不仅收敛速度快,而且具有较高的精确度和抗噪性能。     

基于灰关联分析的顺层钻孔瓦斯抽采有效半径主控因素研究

基于顺层抽采钻孔固气耦合模型,采用COMSOL对钻孔直径、煤层物性参数及抽采参数三类因素进行了模拟分析,并运用灰关联分析方法确定了顺层钻孔瓦斯抽采有效半径的主控因素。研究表明:煤层初始瓦斯压力与煤体初始渗透率为有效半径的主控因素,抽采时间次之,钻孔直径与有效抽采负压的变化对有效半径的影响甚微;提高瓦斯抽采有效半径的首要任务是通过技术手段卸压、增透,其次要把握合理的预抽时间。     

Experimental studies of removing typical VOCs by dielectric barrier discharge reactor of different sizes

This research conducted both lab-scale and pilot-scale tests by selecting toluene as the typical volatile organic compounds (VOCs) and by using the promising non-thermal plasma oxidation technology – dielectric barrier discharge (DBD). To develop baseline engineering data to demonstrate the feasibility of application of self-made DBD reactors, the peak voltage, gas flow speed, initial toluene concentration, discharge frequency and duty ratio were studied. The results showed that toluene removal efficiency improves with increase of electrical voltage, frequency and duty ratio, and declines with increase of polar distance, gas flow speed and toluene initial concentration. When the voltage increases, the energy efficiency rises first and then drops. The energy efficiency reaches the climax when the energy density reaches 150.8 J/L and 101.7 J/L in the lab-scale experiment and pilot-scale experiment respectively.     

天津站地铁换乘中心人群密度调查

人群密度的调查研究对公共场所的安全疏散研究起着至关重要的作用.以天津站地铁换乘中心为研究对象,对其人群密度分布进行了实地调查,通过直接计数法、图像计数法等调查方法采集初步数据,经分析和处理得出此地铁换乘中心人群密度随空间和时间的分布及变化情况,并结合此大型公共建筑的自身特点,分析人群密度分布变化的原因、人群密度较高区域可能发生的事故种类,针对性地提出减缓人群拥挤风险、缓解客流分布不均的具体措施,以便减小因人群密度过大而发生安全事故的概率,减少人员伤亡和财产损失.     

干流倒灌异重流对香溪河库湾营养盐的补给作用

三峡水库蓄水以来,其支流库湾每年均暴发严重的春季水华.为研究三峡水库支流营养盐受干流的逆向影响,于2010年对三峡水库库首区域最大的支流香溪河库湾水流特点及总氮、总磷的时空动态分布进行了详细监测.研究发现库湾水体表现为分层异向流动,存在明显的倒灌异重流现象,分别以表、中、底3种形式倒灌入香溪河库湾;特定的水流特性为库湾营养物质的运输提供了水动力基础,香溪河河口处由干流倒灌输入总氮、总磷的平均瞬时通量分别为501.92 g.s-1、48.17 g.s-1,在2010年干流倒灌输入香溪河库湾的总氮、总磷污染负荷分别占总量的43.4%、21.5%.结果表明,倒灌输入的总氮、总磷占有很大的比例,同时加强三峡水库支流及干流上游流域污染控制才是有效控制支流水华发生的根本途径.     

Diffusion mechanism of chloride ions in sodium montmorillonite

For safety assessment of geological disposal of HLW, it is necessary to understand the diffusion mechanism of radionuclides in compacted bentonite. In this study, the diffusion behavior of chloride ions in compacted montmorillonite was studied from the viewpoints of the activation energy for apparent diffusion and the basal spacing of the compacted montmorillonite. A unique change in the activation energy as a function of the dry density of the montmorillonite was found. The activation energy decreased from 17.4 to 13.5 kJ mol-1 as the dry density increased from 0.7 to 1.0 Mg m-3 and increased to 25.1 kJ mol-1 at dry densities above 1.0 Mg m-3. The basal spacing of 1.88 nm, corresponding to the three-water layer hydrate state, was not observed by X-ray diffraction (XRD) until the dry density increased to 1.0 Mg m-3, where the minimum activation energy was obtained. On the other hand, a basal spacing of 1.56 nm, corresponding to the two-water layer hydrate state, was observed at the dry densities of 1.4 Mg m-3 and above, where the activation energies were more than 22 kJ mol-1. These experimental results suggest that there are at least two additional diffusion processes that can raise or reduce the activation energy and are affected by water in the region adjacent to the montmorillonite surfaces. If the "Grahame model" can be introduced to describe the electrical double layer, surface diffusion will be considered the possible predominant diffusion process, even for anions like chloride ions.