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61.
杜波 《长春工程学院学报(自然科学版)》2016,17(4)
室内空气质量监测系统以STC89C52单片机为主控器,对甲醛、二氧化碳、一氧化碳、可吸入颗粒、温度、湿度信号进行采集和显示,通过键盘设置报警值,配有蜂鸣报警电路和外扩存储电路,系统通过USB接口与上位机进行通讯,实现对检测数据的历史查询和实时监测.系统由电池供电,具有便携式特点,功能实用,方便人们生活,提升生活质量. 相似文献
62.
多天线技术可在不额外增加功率和带宽的条件下成倍提升无线资源的频谱效率,改善通信质量.本文提出了一种适合于室内分布系统场景的多用户MIMO下行链路空分多址算法.首先通过测量不同用户在不同通道上的功率来计算空分多址用户间的信号干扰比值,然后根据该信号干扰比值进行初步的空分多址判决,最后对空分多址用户进行干扰补偿.仿真结果表明该空分多址算法可以大幅提升室内分布系统的容量. 相似文献
63.
Cariton Kubwabo Xinghua Fan Pat E. Rasmussen Fang Wu Ivana Kosarac 《International journal of environmental analytical chemistry》2016,96(7):667-681
Phthalates have been used as plasticisers for several decades in various industry and consumer products. A method was developed for the determination of 13 not commonly monitored phthalates in household dust. The method was based on solvent extraction using sonication, sample clean-up by solid phase extraction (SPE), and analysis using isotope dilution gas chromatography-tandem mass spectrometry (GC/MS/MS). The method was applied to the analysis of dust samples collected using two vacuum sampling techniques from 38 urban Canadian homes: a sample of fresh or ‘active’ dust (FD) collected by technicians and a composite sample taken from the household vacuum cleaner (HD). Spearman rank correlations between HD and FD samples were significant for six phthalates with median concentrations above their method detection limits (MDLs), suggesting that the HD samples provide comparable results with FD samples. Seven phthalates were detected and quantified in a Canada-wide set of 126 household dust samples, among which six phthalates were detected at frequencies higher than 87%, with median (range) concentrations of 1.9 (<0.42–240) (μg/g) for diisohexyl phthalate (DIHxP), 3.8 (<0.16–260) (μg/g) for di-n-heptyl phthalate (DHepP), 6.6 (<1.1–1170) (μg/g) for diisooctyl phthalate (DIOP), 1.1 (<0.12–390) (μg/g) for di-n-octyl phthalate (DOP), 6.3 (<0.16–430) (μg/g) for dinonyl phthalate (DNP), and 1.8 (<0.18–850) (μg/g) for di-n-decyl phthalate (DDP). High detection frequencies and widely scattered concentration levels of these phthalates in this preliminary set of 126 samples suggested a high variability in potential exposure to phthalates in Canadian homes. NIST SRM 2585 (organic contaminants in house dust) was also analysed; eight phthalates were detected, with concentrations ranging from 6.0 μg/g for DOP to 79 μg/g for DIHxP. The results from SRM 2585 may contribute to the certification of phthalate concentration values in this SRM. 相似文献
64.
65.
Odlyha M. Cohen N. S. Campana R. Foster G. M. 《Journal of Thermal Analysis and Calorimetry》1999,56(3):1219-1232
This paper describes the results and conclusions of research directed towards the development and evaluation of a chemical
sensor which would provide information on the quality of indoor environments surrounding cultural objects. In our case these
objects were paintings housed in major European galleries and the main objective is their preservation through an improved
understanding of their microenvironment. The concept was to prepare and expose test tempera paintings which would behave as
dosimeters and integrate the environmental response at these locations. Artificial ageing of similar samples was performed
to provide a means of calibrating the test paintings. Samples from the test paintings were compared with artificially aged
samples and this enabled the sites to be ranked in terms of their suitability for exposure of cultural objects.
Additionally, novel methodology involving piezoelectric sensors was designed for monitoring the relative humidity and temperature
of the microenvironment of paintings. Dielectric techniques were also used for measuring the effect of relative humidity fluctuations
on artists' materials and novel non-invasive dielectric techniques in the microwave region were used for the determination
of their moisture content.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
66.
提出一种基于多神经网络的分布式变电站故障诊断系统的结构和构建方法, 它具有开发耗用低、易于维护、可在线诊断等特点, 并能有效的克服单个神经网络因结构复杂而产生的学习速度慢, 难以收敛等缺点 相似文献
67.
对现代商业室内环境艺术中柱的合理利用及柱的造型设计进行了探讨,并利用大量中外设计实例具体阐述了现代商业室内环境设计中柱的处理及柱式设计的原则与方法。 相似文献
68.
胡大勇 《重庆工商大学学报(自然科学版)》1999,(2)
餐厅的室内环境气氛设计,要了解“影响餐厅气氛的要素及组合”。餐厅环境个性的表达要注意环境个性与功能特征的关系。”主题室内设计”应充分利用各种物质要素来诱发人们对主题的联想和移情。另外还应注意餐厅环境气氛的表现 相似文献
69.
在结构质量现场检测的基础上,将裂缝、腐蚀等损伤表示为截面特征的变化进行模拟,对在役受损变电架构进行了力学分析、结构计算和可靠性鉴定,并着重介绍了架构体系中钢筋混凝土桁架和环形柱的粘贴碳纤维布加固方案。 相似文献
70.
室内污染物逐渐成为人们最为关心的环境问题之一.在讨论了室内污染物主要来源及危害的基础上,利用监测设备对石家庄地区的室内污染物浓度进行了连续监测,分析了不同装修时间对污染物浓度的影响,最后给出了相应的防治建议与措施. 相似文献