碳管法燃煤烟气汞浓度取样装置研制     

汤红健  段钰锋  朱纯  周强  佘敏  蔡亮 《东南大学学报》2015,(2)

自主研制了包括内置吸附剂和两段式碳吸附管在内的整套新型碳管法烟气汞浓度取样装置,以期实现燃煤烟气中颗粒汞和气相总汞浓度的精确测量．在6 kW 燃煤循环流化床装置上同时采用碳管法与安大略标准法（OHM）进行烟气中汞浓度取样．结果表明,碳管法所得汞平衡率均处于95．47％～104．72％之间．不同工况下碳吸附管第2段穿透率始终低于2％,且与相同工况下 OHM 测试结果的相对偏差在15．96％～17．56％之间,均小于20％．结果表明,所研制的碳吸附管干法烟气汞浓度取样装置符合美国 EPA 质量保证和质量控制（QA／QC）标准,可应用于实际燃煤烟气汞浓度的取样测试．  相似文献   

高职临床医学专业学生毕业后去向调查分析——以湖南某高职院校为例     

龙玫 《科教文汇》2021,(1)

该文通过制定调查问卷,对湖南某高职院校在校的2018级、2019级临床医学专业学生毕业后的去向进行了抽样调查,了解了学生毕业后的去向以及影响学生就业的各类因素,以期为学生毕业提供正确的就业指导。  相似文献   

基于DSP的矿用馈电开关保护系统设计     

王党树  王新霞 《实验室研究与探索》2014,33(9):74-77

研制了基于DSP(TMS320F28335)的矿用馈电开关保护系统,系统对三相交流信号调理后送入DSP控制器进行采集,并进行傅里叶运算处理,对供电状况进行判断,给出相应保护措施,用LCD12864显示电网参数及故障信息,并通过RS485与上位机进行通信,上位机采用LabVIEW进行编程,完成对电网运行状况的集中监控和管理。经调试,该系统能够实现三相电压电流采集、过压、过流、漏电、缺相检测、跳闸合闸、显示、历史数据记录、参数设定及上下位机通信等功能于一体的矿用馈电开关保护系统。  相似文献   

Dynamic reciprocal relations of achievement goals with daily experiences of academic success and failure: An ambulatory assessment study     

《Learning and Instruction》2022

Achievement goals have been linked to achievement in various educational settings. The present work explored day-to-day variations in achievement goals (mastery, performance-approach, performance-avoidance) and their associations with daily experiences of academic success and failure. Ambulatory assessment data from 108 students in Grade 5 were collected, with daily assessments of achievement goals in the morning and end-of-day reports of academic success and failure. Dynamic structural equation models revealed reciprocal within-person effects between mastery goals and academic success. Academic success was further associated with higher mastery and performance-approach goals in the next morning. Academic failure was linked to both performance goals, though this association was not robust in all sensitivity analyses. Higher average daily academic success and lower average academic failure were linked to better academic achievement one year later. Findings suggest meaningful within-person dynamics among goals and daily academic success and failure.  相似文献   

FIR数字滤波器的设计与仿真     

陈晓文 《凯里学院学报》2014,(3):111-114

为了减小数字滤波器设计工作量,利用MATLAB软件,采用窗函数法、频率采样法及最优等波纹法设计FIR数字滤波器.通过比较不同设计方法得到的滤波器阶数以及幅频特性曲线,结果表明,最优等波纹法可大大减少了计算的复杂程度,所设计的滤波器简单,是FIR滤波器设计中的最优方法.  相似文献   

港口吞吐量抽样调查方案设计     

余思勤 《上海海事大学学报》1995,(4)

讨论了抽样调查在港口吞吐量调查中的应用前景，分析了港口吞吐量抽样调查方案设计的各个环节，包括：方案设计的原则、技术方法、抽样公式、调查时间、分层确定、季节变动处理和非抽样误差控制等。  相似文献   

Preanalytical phase--a continuous challenge for laboratory professionals     

Simundic AM  Lippi G 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2012,22(2):145-149

Preanalytical phase is the most vulnerable part of the total testing process and is considered to be among the greatest challenges to the laboratory professionals. However, preanalytical activities, management of unsuitable specimens and reporting policies are not fully standardized, nor harmonized worldwide. Several standards related to blood sampling and sample transportation and handling are available, but compliance to those guidelines is low, especially outside the laboratory and if blood sampling is done without the direct supervision of the laboratory staff. Furthermore, for some most critical procedures within the preanalytical phase, internationally accepted guidelines and recommendations as well as related quality measures are unfortunately unavailable. There is large heterogeneity in the criteria for sample rejection, the different strategies by which unacceptable samples are managed, processed and test results reported worldwide. Management of unacceptable specimens warrants therefore immediate harmonization. Alongside the challenging and long road of patient safety, preanalytical phase offers room for improvement, and Editors at Biochemia Medica Journal definitely hope to continue providing a respective mean for reporting studies on different preanalytical phase topics. With pleasure and delight we invite potential future authors to submit their articles examining the quality of various preanalytical activities to Biochemia Medica. We will keep nurturing this topic as our prominent feature and by this we hope to be able to deliver valid evidence for some future guidelines and recommendations.  相似文献   

基于改进的IMM目标跟踪算法研究     

卞丽 《科技通报》2012,28(4):49-51

采用了交互式多模型(IMM)算法进行目标定位跟踪。交互式多模型(IMM)作为一种数据互联算法具有自适应的特点,可以有效地对各个模型的概率进行精细地调整,尤其适用于对机动目标的定位跟踪。实验结果表明,本文提出的算法能够有效地对目标进行定位跟踪。  相似文献   

美国大学终身聘任后评审制政策的网络调查问卷设计及实施     

李阳琇  曾德超 《比较教育研究》2006,27(2):57-61

近十多年来,终身聘任后评审政策在美国掀起了一场运动,引起了广泛关注.但目前国内研究还较少见,尤其定量研究更为缺乏.本文尝试通过网络调查问卷的定量研究来进行.从美国的研究/博士型、硕士型共862所大学总体中,采用分层随机抽样法,抽取公、私立大学共432所为样本,每所大学选择行政官员和教授各1位,直接进行跨国网上问卷调查.本研究表明,采用网络问卷调查法进行外国教育研究是一种成功的研究方式.  相似文献   

分层抽样下多项选择敏感问题随机抽样调查方法及应用     

邱赛兵  唐波 《娄底师专学报》2013,(2):39-41

目的是为多项选择敏感性问题提供科学的、精度更高的随机抽样调查方法及其统计量的计算公式,设计出多项选择敏感问题分层抽样下的随机抽样调查模型,并推导出在此模型下总体比例的估计量及其估计方差的计算公式,计算出敏感属性比例95％的置信区间。并在湖南城市学院本科学生考试作弊情况的实例调查中取得了信誉度较高的应用效果。  相似文献