在线红外水分仪的一种校准方法

用动态被测物料作为校准介质,再用重量法对选取的样品定值,以此校准在线红外水分仪。     

Experimental study on axial development of liquid film in vertical upward annular two-phase flow

Accurate measurements of the interfacial wave structure of upward annular two-phase flow in a vertical pipe were performed using a laser focus displacement meter (LFD). The purpose of this study was to clarify the effectiveness of the LFD for obtaining detailed information on the interfacial displacement of a liquid film in annular two-phase flow and to investigate the effect of axial distance from the air–water inlet on the phenomena. Adiabatic upward annular air–water flow experiments were conducted using a 3 m long, 11 mm ID pipe. Measurements of interfacial waves were conducted at 21 axial locations, spaced 110 mm apart in the pipe. The axial distances from the inlet (z) normalized by the pipe diameter (D) varied over z/D = 50–250. Data were collected for predetermined gas and liquid flow conditions and for Reynolds numbers ranging from Re_G = 31,800 to 98,300 for the gas phase and Re_L = 1050 to 9430 for the liquid phase. Using the LFD, we obtained such local properties as the minimum thickness, maximum thickness, and passing frequency of the waves. The maximum film thickness and passing frequency of disturbance waves decreased gradually, with some oscillations, as flow developed. The flow development, i.e., decreasing film thickness and passing frequency, persisted until the end of the pipe, which means that the flow might never reach the fully developed state. The minimum film thickness decreased with flow development and with increasing gas flow rate. These results are discussed, taking into account the buffer layer calculated from Karman’s three-layer model. A correlation is proposed between the minimum film thickness obtained in relation to the interfacial shear stress and the Reynolds number of the liquid.     

基于数字摄像的测量观测系统设计

在大气能见度观测中,相关研究多集中于白天观测,夜间观测的研究比较少见,而对于昼夜连续观测的研究更是鲜有报道。目前,国内外尚没有完全按照能见度定义研制的大气能见度自动观测仪出现。针对这一问题,基于CCD数字摄像技术,模拟人工观测光学原理,提出了一种能够昼夜进行大气能见度连续观测的方法。该方法基于对目标物获得能见度计算公式,并针对昼夜模式下的系统参数进行修正,能够有效消除外在环境因素和相机自身系统内部因素引发的观测误差。为验证算法的有效性,针对天空遮挡、半遮挡和空旷等不同情况(不同情况,会影响观测环境的亮度,以此测试系统对杂散光的抵抗能力,以及对不同环境的适应能力),搭建了基于该方法的3套原理样机。利用搭建的数字摄像能见度仪(DPVS)在北京地区进行了实际的大气能见度分钟级观测。观测实验表明,基于该方法构建的观测系统,不但具有较宽的观测范围,而且能够有效适应各类复杂天气情况,在雨雪霾等不同天气下,均有较好的观测效果,且无论是在能见度变化较快或者较为缓慢的情况下,DPVS系统均能够进行快速正确的响应。而透过DPVS与散射仪和透射仪这两种标准观测仪器观测结果的对比分析发现,DPVS与前两者的观...     

高能激光能量计校准方法研究

给出了一种绝对式高能激光能量计光电校准方法.该方法以大功率灯作为校准光源,通过测量灯两端的电压以及电流获得电能值,去掉灯所消耗的热能,得到灯所发出的光能.所设计平板能量计将大功率灯密封在高能激光能量计内,光能全部被能量计吸收.根据能量计输出值以及光能值便可实现能量计光电校准.结果表明,能量计光电校准不确定度约为1.5%.     

用硅光电池制作光功率计实验

介绍使用运算放大器以及硅光电池制作光功率计的原理以及制作的过程。实验涉及到运算放大器以及硅光电池光谱响应等基础知识。     

三光纤干涉型波分复用器的理论分析与实验

本文提出一种由三根长度不等的单模光纤作为干涉臂连接两个3×3耦合器而成的干涉型超窄三波分复用器,并对其进行了理论分析与实验研究文中给出了三角型3×3耦合器的传输矩阵及三根干涉臂的长度之差与复用波长的关系,并由此导出了整个系统的功率传输式理论分析与实验曲线基本一致我们实验样品的使用波段为155μm,波长复用间隔为16nm,插入损耗约06dB,三个端口的隔离度分别在13～16dB之间.     

冷原子荧光测汞仪检定结果的不确定度

依据JJG548-2004对冷原子荧光测汞仪进行检定时,检定结果的不确定度主要来源于仪器的线性误差、检测限、重复性和标准物质浓度。对各不确定分量进行了评定和计算,求得合成标准不确定度和扩展不确定度分别为0.033ng/mL和0.066ng/mL(k=2)。     

应用单相流量计测量油水两相流

为探讨单相流量计用于液液两相流参数测量的可行性和有效性,本文对文丘里管、涡轮流量计和椭圆齿轮流量计用于油水两相流测量的响应特性进行了实验研究.文丘里管和涡轮流量计的实验管径为15 mm,25 mm,40 mm,椭圆齿轮流量计的实验管径为25 mm和40 mm.油水两相流总体积流量范围为1～5 m3/h,油含率范围为15%～85%.实验结果表明,文丘里管在高油含率时测得的油水两相流流量比实际流量偏大4%～5%.涡轮流量计的测量误差随油含率升高呈现增大的趋势,最大测量洪差小于5%.椭圆齿轮流量计用于油水两相流测量时相对测量误差小于1.0%且基本不受油含率影响.     

The Electrochemiluminescent Immunosensors for Point-of-Care Testing of Methamphetamine Using a Portable Meter

The crowd of methamphetamine (METH) abuse has obviously increased during past decades, their physical and mental health are seriously jeopardized. It compelled growing worry worldwide so that there is an anxious requirement to develop the accurate, sensitive, rapid, and convenient detection techniques to tackle the problem. In regard to this matter, we reported two sensors for METH with synergistical alliance of sensitive electrochemiluminescence (ECL) quantification and specifically immune recognition. These sensors are applicable for point-of-care testing when equipped a portable ECL meter with outstanding performance, makes the feasibility of on-spot analysis. The dual-way analysis of immunosensors can be carried on, both exhibit unprecedented sensitivity toward METH. Here, AuNPs functioned indium tin oxide (ITO) coated polyethylene terephthalate (PET) is used as the basal electrode, providing excellent ECL background and supporting the sensing matrix. The real sample identification demonstrated the practicability and accuracy which met the requirement of forensic judgement and clinical treatment. This work provides a viable methodology and technology for a rapid and reliable analysis of hard drug abuser's samples.     

自动校准型pH计电计输入阻抗引起的示值误差检定方法的探讨

由于一些自动校准型pH计设置的校准点与计量检定规程要求的pH 7(或电计等电位值)无法对应,探讨了用pH 6.86点代替pH 7点,解决了电计输入阻抗引起的示值误差无法按照计量检定规程要求进行检定的问题。通过实验验证了该方法的可行性。