县域村庄空间布局优化的探索和实践——以河北省武安市域村庄空间布局规划为例

以河北省武安市市域村庄空间布局规划为例,分析了地形地貌特点和资源条件对村庄规模、村庄密度、农村经济和村庄空间布局形态的影响,针对不同地貌类型和区位条件,提出不同的村庄迁并标准、布局调整重点和分类指导方案,探讨了丘陵、山地村庄空间布局规划的方法和思路。     

Similarity of coupled heat and mass transfer between air–water and air–liquid desiccant direct-contact systems

Packed-bed heat and mass transfer devices are widely used in air-conditioning systems, such as cooling tower, evaporative cooler of air–water direct-contact devices, dehumidifier and regenerator of air–liquid desiccant direct-contact devices. Similarities of heat and mass transfer characteristics between air–water and air–liquid desiccant devices are considered and investigated in this paper. Same reachable handling region of outlet air can be obtained for both air–water and air–liquid desiccant devices, which is among three boundary lines, isenthalpic line of inlet air, iso-relative humidity line of inlet fluid (water or desiccant), and the connecting line of inlet statuses of air and fluid. Inlet conditions of air and fluid affect heat and mass transfer characteristics to some extent, so that a zonal method is proposed only according to the relative statuses of inlet air to inlet fluid. Four zones, dehumidification zones A, D and regeneration zones B, C, are divided for air-desiccant direct-contact devices. The first three zones A, B and C are divided for air–water direct-contact devices, with the same zonal properties as those of air-desiccant devices. In order to obtain better humidification performance, fluid should be heated (in zone C) rather than air (in zone B). And fluid should be cooled (in zone A) rather than air (in zone D) to obtain better dehumidification performance. Counter-flow pattern should be applied for best mass transfer performance in the same conditions within the recommended zone A or C, while parallel-flow pattern is the best in zone B or D.     

人工湿地处理北方小区生活污水

介绍了沈阳浑南人工湿地示范工程的运行效果,为北方寒冷地区应用湿地技术处理生活污水提供了技术支持与保证.当进水COD为182～423 mg/L、NH3-N为42.0～69.45 mg/L、TP为4.11～8.0 mg/L时,对上述指标的平均去除率分别为90.85%、98.38%、89.68%,出水水质达到国家排放标准.在冬季增加保温措施后,垂直流人工湿地不仅可以安全越冬,利用水流的进入和排出还可有效地与大气进行气体交换,缓解床体内氧气的不足,大大提高对污染物的去除率,达到与其他季节相近的处理效果.     

严寒地区粘贴EPS板外墙外保温薄抹灰面层施工质量控制

针对严寒地区粘EPS板外墙外保温薄抹灰系统应用以来出现的质量问题,提出材料控制、基层控制、粘贴控制、锚栓加设、系统终端控制、面层及滴水线控制、嵌缝胶施工等质量控制措施并提出建议。     

厢式货车在桥塔区域的气动力特征研究

以曼牌16.170F货车及象山港大桥为背景,加工制作了曼牌货车和象山港大桥的1∶25缩尺模型,在TJ-3风洞,使用六分量测力天平对货车模型进行了测力试验,通过试验得到了货车在双向四车道,五个风偏角,相对于桥塔的五个不同位置以及无桥塔状态时的气动力系数。     

Multiple current peaks and spatial characteristics of atmospheric helium dielectric barrier discharges with repetitive unipolar narrow pulse excitation

Atmospheric dielectric barrier discharges driven by repetitive unipolar narrow pulse excitation are investigated numerically by using one-dimensional fluid models.The one-dimensional simulation focuses on the effects of applied voltage amplitude,pulse repetition frequency,gap width and γ coefficient on the multiple-current-pulse (MCP) discharge.The results indicate that the MCP behavior will lead to the stratification of electron density distribution in axial direction.Traditional MCP manipulating methods,such as reducing the applied voltage amplitude,increasing the applied voltage frequency,adjusting the gap width,cannot regulate MCPs exhibiting in this work.Further analyses reveal that the increasing electric field of the cathode fall region is the basis for the emergence of MCP behavior.     

基于区域生长和背景配准的低信噪比红外目标检测算法

为了进一步提高复杂背景下低信噪比红外运动目标的检测性能,提出了一种基于区域生长和背景配准的低信噪比红外运动目标检测算法。该算法首先利用局部对比度找出几个种子点;然后根据种子点进行区域生长,统计生长出目标的相关特征;接着采用多帧关联的方法,挑选出候选目标;最后采用背景配准的方法,剔除虚假目标,降低虚警概率。采用大量实验数据进行仿真验证,仿真结果表明,相对于传统算法,本文算法对低信噪比红外运动目标具有较高的检测概率,较低的虚警概率。     

大采高综放开采顶煤采出率研究

为了探讨大采高综放开采顶煤采出率,以塔山矿8206工作面为工程背景,运用PFC2D软件和顶煤运移跟踪仪对顶煤受力特征、放出率和放出顺序等进行研究。结果表明:顶煤可分为煤体运移特征不同的四个不同受力区域;不同位置顶煤放出率相差较大,上分层低于下分层、中分层,工作面两端回收率较低;顶煤冒落顺序为下部先于上部。可通过加强初末采及端头顶煤回收、改善顶煤冒放性、选择合理放煤步距和放煤方式、加强生产管理等措施,提高采出率。     

三江北段地球化学分区及特征

青海三江北段成矿带是指我国著名的西南三江成矿带的北延部分,是地质找矿最具潜力的地区之一。 笔者将三江北段划分了3个地球化学区,即西金乌兰—玉树地球化学分区、沱沱河—杂多地球化学分区、雁石坪地球化学分区,分析了它们的特点。沱沱河—杂多地球化学分区Pb、Zn、As、Sb、Mn、Cd、Nb、Sr等元素表现为富集;各地球化学分区主要成矿(相关)元素排序方式表明Pb、Zn、Cd、As、Sb、Mn、Cu、Ag、Mo、Fe等元素不但处于明显富集状态,而且分布极不均匀,形成了三江北段内特定的元素组合。地球化学分区为该区的找矿方向、成矿远景评价及基础地质调查奠定了基础。     

双馈风电机组抑制电力系统低频振荡的鲁棒控制策略

针对大规模风电场接入电力系统面临的低频振荡问题,提出了一种双馈风电机组(doubly-fed induction generator,DFIG)附加鲁棒控制策略,通过控制双馈风电机组的转子侧无功输出向系统注入无功功率以达到提升系统阻尼的目的。首先采用TLS-ESPRIT辨识算法辨识出系统模型,然后采用基于区域极点配置的鲁棒控制理论设计附加阻尼控制器。为对所提控制方法相比于传统控制方法的优势,设计了基于极点配置的阻尼控制器。最后在PSCAD软件中搭建含风电的两区域模型验证所提控制方法的有效性。仿真结果表明DFIG附加鲁棒控制器能有效抑制电力系统低频振荡,具有较好的鲁棒性。