Intra-storm variability in microbial partitioning and microbial loading rates

Association with particles in the water column can have a significant impact on microbial fate and transport. This study analyzed multiple stormwater samples taken throughout the duration of three separate storms (at two different sites) to evaluate the fraction of microbes partitioning to denser "settleable" particles and to examine how partitioning behavior varied over the course of a storm. Intra-storm sampling also allowed for estimates of microbial loading rates (both total and particle-associated) and cumulative storm-induced microbial load. Five different indicator organisms were examined, with the fraction of microbes associated with settleable particles assessed via a calibrated centrifugation method. Partitioning behavior varied across microorganism type, with an average of 40% of fecal coliforms, Escherichia coli, and enterococci associating with settleable particles, compared to approximately 65% of Clostridium perfringens spores and only 13% of total coliphage. Partitioning remained fairly constant for each type of organism throughout storm events. Nonetheless, higher concentrations of both settleable particles and microbes entering the water column soon after the onset of a storm led to higher loading rates of settleable microbes in the storm's earliest stages, a trend that could have important implications for the design of stormwater management structures (e.g., detention basins). Estimates of cumulative storm-induced microbial loading suggested that one day's worth of storm loading can be the equivalent of months, or even years, of dry-weather loading.     

马尾松纤维细胞腔加填的研究

以国内南方的马尾松纤维为原料,利用高速搅拌作用将二氧化钛粒子加填进入纤维细胞腔内,探讨了加填工艺参数及助剂阳离子聚丙烯酰胺(CPAM)的使用对加填的影响,用扫描电镜观察了加填前后纤维的横截面.结果表明:打浆后的浆料纤维不适用于细胞腔加填;混合搅拌30～45min、浆料浓度0.5%～2.0%时加填效果较好;增大填料浓度能提高加填量;使用CPAM能提高加填量,其使用量0.05%～0.4%时效果较好;电镜观察显示加填后填料粒子很好地留着在细胞腔内.     

电涌保护器质量监管与抽样检测的探讨

阐述了SPD质量监管的必要性,并对监管的主要手段——抽样检测进行了探讨和思考。围绕抽样方法,探讨了抽样环节、抽样过程以及各项注意要点。选取了5个代表性的检测项目,探讨了检测的特点以及检测对SPD质量监管的意义,并阐述了承担抽样检测的检测机构所应具备的资质和能力,以提升SPD行业整体质量。     

Hybrid Chemical Reaction Optimization Approach for Combined Economic Emission Short-term Hydrothermal Scheduling

—This article presents the hybridization of a newly developed, novel, and efficient chemical reaction optimization technique and differential evolution for solving a short-term hydrothermal scheduling problem. The main objective of the short-term scheduling is to schedule the hydro and thermal plants generation in such a way that minimizes the generation cost. However, due to strict government regulations on environmental protection, operation at minimum cost is no longer the only criterion for dispatching electrical power. The idea behind the environmentally constrained hydrothermal scheduling formulation is to estimate the optimal generation schedule of hydro and thermal generating units in such a manner that fuel cost and harmful emission levels are both simultaneously minimized for a given load demand. In this context, this article proposes a hybrid chemical reaction optimization and differential evolution approach for solving the multi-objective short-term combined economic emission scheduling problem. The effectiveness of the proposed hybrid chemical reaction optimization and differential evolution method is validated by carrying out extensive tests on two hydrothermal scheduling problems with incremental fuel-cost functions taking into account the valve-point loading effects. The result shows that the proposed algorithm improves the solution accuracy and reliability compared to other techniques.     

工程结构的多工况离散变量优化设计

基于工程结构的单工况优化设计的数学模型,建立了工程结构的多工况优化设计数学模型;根据材料特点,将设计变量取为离散变量,提出了工程结构的多工况离散变量优化设计数学模型.对25杆空间桁架结构的优化计算,表明了该方法的可行性.     

基于压电式压力传感器的冲击波载荷测试系统设计

为了满足对爆炸冲击波载荷精确测量的技术要求,设计了以压电式压力传感器为测试元件的爆炸冲击波载荷测试系统,并对所选压电式压力传感器的固有频率ωn与采样频率ω的关系进行了研究。试验表明,所选压电式压力传感器及设计的测试系统性能稳定、可靠,测试结果符合设计要求。     

浅谈汽车衡在筒仓快速定量装车中的应用

针对煤矿筒仓快速定量装车的需求,提出基于汽车衡称重技术,以汽车代替称量容器,通过采集汽车的重量信号,控制定量装车的新的装车模式和流程。汽车衡的应用,实现了煤矿筒仓的动态装车和静态计量的同步完成,在保证了装车精度和计量精度的同时,提高了装车效率。     

一种筒仓快速定量装车系统

根据筒仓定量装车的需求,充分考虑现场工况条件,提出一种筒仓快速定量装车系统。通过对汽车衡的台面长度和位置分析、装车配料的流量计算等,实现边装车边计量的快速定量装车模式。该系统一次性完成装车和计量,减少了车辆流通压力,避免了超载、欠载情况,在保证装车精度和计量精度的前提下,提高了装车效率。     

基于TMS320DM642的Flash头文件烧写法的DSP二级BootLoader开发

针对DM642掉电后驻留在内部存储器的数据和程序将全部丢失无法实现DSP系统脱机工作的问题,提出了一种利用DSP的Boot机制从外部Flash存储器自动加载程序的方法。详细介绍了Flash头文件烧写方法原理;针对Am29LV033C Flash芯片设计了Flash头文件法烧写程序,详细说明了两次程序加载方法并给出Flash烧写过程;介绍了如何使用CCS保存数据,以生成头文件;简要介绍了DSP引导过程及二级Bootloader程序开发,设计了有项目针对性的二级Bootloader程序。最后,通过编写简单的测试程序验证Flash烧写方法及二级Bootloader引导程序。研究结果表明,Flash头文件烧写法简单易懂,适合初学者学习,对不同型号Flash芯片操作只需简单修改指令字,可移植性强,易于实现DSP的二级Bootloader开发。     

基于转矩补偿的风电变桨加载系统的研究及仿真

针对风电变桨加载系统在建模及控制方法上存在的缺陷,对桨叶模拟系统的补偿转矩进行了研究分析,对加载系统中的控制方法进行了改进,提出了一种转矩闭环控制与转矩补偿优化相结合的控制方法.基于Bladed软件对2.5 MW风电机组运行进行了仿真,同时利用该模型模拟现场工况,参与平台控制并进行了加载试验,将平台试验数据与仿真结果进行了比较,两者基本一致.研究结果表明,转矩闭环控制与转矩补偿优化相结合的控制方法能真实反映桨叶在风场的工况,使变桨加载系统的控制达到最优.