共查询到20条相似文献,搜索用时 187 毫秒
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建立了一种以容量瓶为萃取容器的液-液小体积萃取GC-MS快速测定地表水中硝基苯类、氯苯类及邻苯二甲酸酯类化合物的分析方法。该方法具有操作简单快速、适用性广和试剂用量很少等特点。当萃取试剂用量为1mL时(约为一般常规液液萃取用量的数十分之一),萃取富集效率可达100倍,回收率为76%~120%,相对标准偏差为3%~8%,检出限为0.2~0.9μg/L。对实际地表水水样中的硝基苯、氯苯类及邻苯二甲酸酯化合物进行了定性定量分析,结果令人满意。 相似文献
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提出了润滑系统油品含水率多点在线实时监测系统的实现方法,设计了基于变介电常数式电容传感器的润滑油品含水率变送器,根据高速线材厂液压循环润滑系统的特点,利用组态王软件,实现对液压系统的润滑油含水率进行多点实时监测.通过在高速线材厂液压循环系统的使用证明,该系统能够准确、快速地测出润滑油品的含水率并及时报警,从而避免了润滑失效所带来的潜在危害. 相似文献
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电磁搅拌对BFe10-1-1白铜管坯的影响 总被引:1,自引:0,他引:1
采用试验的方法研究了在水平连铸过程中施加工频旋转电磁场对BFe10-1-1白铜管坯表面质量、凝固组织和力学性能的影响,并考察了电磁搅拌对管坯室温拉伸性能的影响.结果表明,采用水平电磁连铸短流程工艺能够制备出高质量的白铜管坯,电磁搅拌能够避免管坯表面热节瘤等缺陷的形成,同时促使粗大柱状晶发生细化,并使溶质元素宏观偏析得到了抑制;电磁搅拌能够提高管坯的抗拉强度和塑性,当线圈电流为100A时管坯抗拉强度较普通连铸坯提高了9%,而延伸率则提高了55%. 相似文献
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针对当前成品油含水率实时检测的实际需求,提出一种基于密度检测原理的非接触式成品油含水率及油位智能化检测系统的设计方案,应用超声波及差压传感器对成品油库内的油品含水率进行实时非接触式的全自动检测。该系统基于可编程片上系统进行设计,用于实现油位、油压和现场温度的测量以及实现测量结果的显示、人机交互等功能。 相似文献
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不规则形状容器容积的两种快速标定方法 总被引:1,自引:0,他引:1
《真空科学与技术学报》2015,35(1)
针对特殊内部结构的容器,常规容积测量方法无法简便有效地实现测定,为此本研究设计了一套新颖的容积标定装置,提出了两种快速标定方法。这两种标定方法是在真空条件下获取容器内压力变化Δp和抽取气体累积体积ΔV的数据,基于气态方程和线性回归方法建立关系表达式,从而能直接计算出待标定容器的容积。实验结果表明,测定所得数据相对偏差在±3.0%以内。本文对该标定装置的主要影响因素即水分等挥发性物质、质量歧视效应、系统仪表精度进行了分析和计算,计算结果表明:本装置在容器内不含挥发性物质、系统仪表精度较高的情况下,适用于特殊结构容器容积的快速测定。 相似文献
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针对传统油水乳状液含水率测量装置的准确性低、成本高、无法实现动态测量的问题,设计一种剪切条件下乳状液含水率的测量装置。系统利用油水两相的介电及电导特性的差异性,采用交流阻抗法测量待测乳状液的复阻抗参数,从而获得乳状液的含水率特征。结合搅拌装置模拟油水乳状液在运输环境下的剪切环境,间接实现油水乳状液的动态测量。实验测试表明:装置具有良好的重复性和稳定性,可实现剪切条件下对乳状液复阻抗参数的测量,证明乳状液的阻抗参数与含水率存在明显的线性关系,对进一步研究管道中油水两相的流动性质具有一定的参考价值。 相似文献
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本文介绍了一种用电容测量法快速测量粮食水分的试验装置.在干燥粮食的过程中,利用含有两个放大器的非变压器桥路自动测量粮食水分并进行反馈控制.此装置的测量分辨率可达10-14F. 相似文献
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In the present study different approaches for determination of the limits of linear viscoelastic (LVE) behavior are considered
on examples of some thermoplastic and thermosetting polymers. Stress or strain level, commonly considered as a limit of LVE
behavior, are interrelated time-dependent functions strongly influenced by action of external factors. The concept of energy
threshold has an advantage of combining into one physical function the effects of both stress and strain in initiating nonlinear
behavior. The value of the stored deviatoric energy is considered as a limit of LVE behavior and is a material characteristic.
The experimental data on tension at various constant strain rates and tensile creep at various stresses, temperatures, and
moisture conditions are considered. It is proved for some polymers that LVE limits in stress-strain representation fall on
a common curve that is an energy curve independent of time. Decrease of the test rate or growth of temperature or moisture
content appears only in a shift down along the energy curve to the lower limit stresses and higher limit strains. 相似文献
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目的 针对现实工业生产情况中存在的排污管道藏匿问题,更便捷和高效地在已知或是未知污染的水体中寻找到藏匿的排污口。方法 通过对水体污染物测量方法的研究,选用可以同时拥有实时反馈和方便对比的离子测定法,设计对无机污染物离子的小型自动水质检测装置。该装置在电流传感器及自动化控制程序的基础上拥有水样采集、检测、自动化寻踪及实时定位等功能。通过模拟工业生产中较为常见污水匿排的场景进行实验,采用原子吸收光谱法验证水污染源自动导巡机检测功能的可靠性。结论 试验中水污染源自动寻导机的运动行径符合预期,证明该水污染源自动导寻机的原理可行并且设计合理。该无机水污染源自动导巡机的设计为同类产品的设计开发提供了指导性的思路。 相似文献
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基于物联网设计了一种轴承噪声测量仪管理系统,该系统包括设备控制终端、智能管理终端和管理中心服务器三层结构.设备控制终端利用PLC、传感器等实现设备工作状态的现场实时数据采集和处理;智能管理终端利用嵌入式技术实现现场显示、权限识别和通信管理等功能;管理中心服务器实现集中显示、管理和自动存档、用时管理和使用效率分析等功能.结果证明,该系统可以实现对设备的有效管理,此外还解决了大型设备数据接口不一致,难以接入互联网的难题. 相似文献
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This paper demonstrates our optical measurement system based on near-infrared tunable diode laser absorption spectrometry and reports the results of trace moisture determination in nitrogen and ammonia gases. A near-infrared InGaAsP distributed feedback diode laser operating at room temperature was employed as the optical source. We used a dual-cell detection strategy to cancel common mode noise from the diode laser and remove the effect of the residual moisture absorption in the beam path outside the sample cell. We also used this method to successfully eliminate the interfering absorption of matrix gas molecules such as NH(3). The detection limit of H(2)O absorption of 4 ppb in nitrogen and 12 ppb in ammonia was obtained using a single-pass absorption cell of only 92 cm in length and the average results of 10 scan measurements. This system has characteristics of both the high sensitivity and capability of in situ and real-time measurement. 相似文献
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We have developed a field-portable optical gas sensor for the ultra-sensitive detection of ethane. The system is based on an adaptation of a commercially available system, which uses a cryogenically cooled, lead-salt laser diode at 3.34 μm and a multi-pass astigmatic Herriott sample cell. We have adapted this system to a second derivative wavelength modulation scheme giving a lower detection limit of less than 100 parts per trillion for a one second measurement time. Our custom-designed software controls every aspect of the instrument operation from spectral scanning of the laser diode, to automatic calibration, optical alignment, spectral analysis and complete data logging. 相似文献
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Determination of moisture distributions in porous building materials by neutron transmission analysis 总被引:1,自引:1,他引:0
The movement of moisture inside building structures can affect them in important ways, causing physical and chemical damage. Therefore the study of moisture transport in porous building materials is highly relevant to a better understanding of the durability of building structures made of porous materials. The moisture transport can be described phenomenologically by a diffusion equation using a moisture content dependent moisture transfer coefficient. To determine the transfer coefficient in a given material, the experimental quantitative measurement of the time and space dependent moisture distribution in the material is necessary. Neutron radiography provides a highly sensitive non-destructive method for the detection of the presence of water and provides high spatial resolution. A new neutron transmission analysis technique has been developed and optimized for the study of moisture in building materials to extract the quantitative information from the experimental data. Typically, moisture contents down to a few mg/cm3 can be detected at a spatial resolution of 1 mm. As an application example, the determination of the time and space dependent moisture distribution in a brick sample and the subsequent determination of the moisture transfer coefficient are presented. 相似文献
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目的在分拣包装应用中,实现工业机器人使用指定的压变设置对物体进行夹取作业。方法设计由PLC、机械夹手、触摸屏、工业机器人组成的夹取系统。其中采用三菱FX系列PLC为控制中心,具有多传感器的机械夹手为末端执行器,三菱GS系列触摸屏为交互界面,安川工业机器人为运动机构。根据夹取流程,采用PLC分析夹取限位、闭合限位、压力检测、变形检测等传感信息,并协调各部分运行。结果系统能够在设定的压变范围内,实现对适用物体的自动夹取作业,并且通过触摸屏可便捷查看检测信息及设置参数。结论该系统能够基于多传感器的检测进行机器人夹取作业,且参数可调控,适用于自动化夹取作业。 相似文献