基于预压水激波管的压力传感器动态校准实验研究

针对目前国内水下冲击波压力传感器校准方法存在的缺陷,提出了一种基于预压水激波管的压力传感器动态校准实验方法.分析了预压水激波管比对式动态校准原理,研究了传感器动态特性影响因素,基于所组建的标准压力监测系统对水下冲击波压力传感器进行了动态校准实验,并采用傅里叶变换法得出了水下冲击波压力传感器的动态特性.实验结果表明,基于预压水激波管的压力传感器动态校准实验方法可以有效地对压力传感器进行动态校准并准确地获取其动态特性.     

数字化测量仪器的逐点动态校准方法研究

本文针对传统动态校准方法用于校准数字化测量仪器存在的不足,通过分析比较目前国内外采用的几种动态校准方法,提出了数字化测量仪器的逐点动态校准方法及系统组成方案.     

可溯源动态压力校准方法

动态压力测试与校准技术越来越受到重视,校准的技术手段也越来越多,但关键的溯源问题已经明显制约了动态压力测试校准技术的发展与推广.本文比较分析了阶跃压力、脉冲压力、正弦压力三种主要的动态压力激励信号的主流校准溯源方法,以及它们在可靠溯源方面存在的不足,尤其是使用越来越多的脉冲压力与正弦压力校准.通过对各种测量原理的可溯源动态压力校准方法以及世界各国最新研究进展情况的全面分析归纳,总结出基于运动参数与动力学方程的动态压力测量方法与基于折射率变化的激光干涉动态压力测量方法等两个重点研究方向.     

锁相放大器的校准方法

介绍了锁相放大器的一种校准方法.讨论了锁相放大器的相敏特性、满刻度灵敏度和本机噪声、动态储备、动态范围以及时间常数参数的校准实现方法,结合校准系统对典型参数的测量不确定度进行了评定.     

建立我国动态参量的计量基准体系

本文论述了建立动态参量计量基准的必要性,频域校准原理,频率特性的直接校准方法,频率特性的准-δ校准方法,介绍了已经研究过的高压力,高温度的准-δ校准方法,论述了建立国家级动态参量基准站的可行性.     

压电式压力传感器的一种动态建模方法

针对数学模型在动态校准实验数据处理中的重要地位,结合激波管对压力传感器测试系统动态校准所得实验数据,介绍了一种基于广义最小二乘法的动态数学模型建立方法.并利用Matlab/Simulink模块进行了仿真验证,由仿真结果表明该时间域数据处理方法具有简洁性、准确性的特点,特别适合于动态校准中建立差分方程模型.     

2m比长仪动态校准位移传感器的研究

介绍了2m比长仪的改造及其功能的拓展,用其校准大量程位移传感器的方法.以校准激光三角法位移传感器为例,采用动态校准方法实现可外触发位移传感器的校准.对德国米依公司optoNCDT1700激光位移传感器进行了校准实验,在比长仪滑板运动速度为1mm/s情况下进行了动态测量,实验验证了传感器的全量程线性度小于0.08%FSO.     

加速度计动态校准装置的研究

加速度计动态校准装置的研究是在加速度计静态校准的基础上提出的.针对加速度计动态校准领域中在大加速度、低频范围内的校准,本文论述了加速度计动态校准发展现状,主要从校准装置的原理、组成和不确定度分析等几方面进行了研究,最后对该校准装置的下一步研究领域进行了展望.     

GNSS动态面积测量仪计量校准方法研究

本文对GNSS动态面积测量仪的校准方法进行了研究和实验验证.从定位偏差和精密度、距离测量误差、面积测量误差3个技术指标,进行具体的校准方法分析,采用不同厂家的GNSS动态面积测量仪进行对比试验,验证了所述校准方法具有良好的可操作性且易于实现,试验数据可以达到技术指标的应用要求.     

测压铜球准动态校准实践

简要介绍了测压铜球的工作原理、使用方法及发展过程,阐明了测压铜球准动态校准的含义及其实现方法.分析了准动态校准铜球压力对照表的编表误差,根据大量的动标数据分析了准动态校准压力对照表适用的膛压信号上升时间的变化范围.结合动标数据分析,给出了被测压力上升时间变化时铜球查表压力的修正公式.说明了测压铜球作温度修正的必要性及实用的修正方法.     

热式气体流量计原理及影响因数分析研究

讨论了热式探头的气体流量测量方法和热式流量仪表的设计方法.在论述热式探头测量气体流量原理的基础上,对探头型式、安装方式、环境温度、供电电源等影响因素进行了较深入的分析,并对热式流量仪表的设计提出了建议.     

滞止式温度传感器动态理论建模研究

根据滞止式温度传感器的换热原理建立了动态理论传热模型,采用数值计算方法对模型方程进行了求解,并对计算结果进行了分析.     

A noncontact temperature measurement method in polymerase chain reaction reactors

A new noncontact method for measuring temperatures of liquids, which is based on the fluorescent probes, is proposed. The method is intended for measuring temperatures of reaction media in reactors of devices for polymerase chain reactions in real time and can be used for determining dynamic temperature parameters.     

Batch fabrication of atomic force microscopy probes with recessed integrated ring microelectrodes at a wafer level

A batch fabrication process at the wafer-level integrating ring microelectrodes into atomic force microscopy (AFM) tips is presented. The fabrication process results in bifunctional scanning probes combining atomic force microscopy with scanning electrochemical microscopy (AFM-SECM) with a ring microelectrode integrated at a defined distance above the apex of the AFM tip. Silicon carbide is used as AFM tip material, resulting in reduced mechanical tip wear for extended usage. The presented approach for the probe fabrication is based on batch processing using standard microfabrication techniques, which provides bifunctional scanning probes at a wafer scale and at low cost. Additional benefits of batch fabrication include the high processing reproducibility, uniformity, and tuning of the physical properties of the cantilever for optimized AFM dynamic mode operation. The performance of batch-fabricated bifunctional probes was demonstrated by simultaneous imaging micropatterned platinum structures at a silicon dioxide substrate in intermittent (dynamic) and contact mode, respectively, and feedback mode SECM. In both, intermittent and contact mode, the bifunctional probes provided reliable correlated electrochemical and topographical data. In addition, simulations of the diffusion-limited steady-state currents at the integrated electrode using finite element methods were performed for characterizing the developed probes.     

单屏蔽式温度传感器动态建模及补偿技术研究

单屏蔽式温度传感器一般用来测量发动机高速气流总温,本文依据其动态校准试验数据,采用系统辨识方法建立了它的动态试验数学模型.根据辨识的数学模型,采用一种快速的动态补偿算法,得出了传感器动态补偿器的传递函数,为下一步在硬件上设计实用的温度传感器动态补偿器打下了坚实的基础.     

Intracellular Labeling with Extrinsic Probes: Delivery Strategies and Applications

Extrinsic probes have outstanding properties for intracellular labeling to visualize dynamic processes in and of living cells, both in vitro and in vivo. Since extrinsic probes are in many cases cell‐impermeable, different biochemical, and physical approaches have been used to break the cell membrane barrier for direct delivery into the cytoplasm. In this Review, these intracellular delivery strategies are discussed, briefly explaining the mechanisms and how they are used for live‐cell labeling applications. Methods that are discussed include three biochemical agents that are used for this purpose—purpose‐different nanocarriers, cell penetrating peptides and the pore‐foraming bacterial toxin streptolysin O. Most successful intracellular label delivery methods are, however, based on physical principles to permeabilize the membrane and include electroporation, laser‐induced photoporation, micro‐ and nanoinjection, nanoneedles or nanostraws, microfluidics, and nanomachines. The strengths and weaknesses of each strategy are discussed with a systematic comparison provided. Finally, the extrinsic probes that are reported for intracellular labeling so‐far are summarized, together with the delivery strategies that are used and their performance. This combined information should provide for a useful guide for choosing the most suitable delivery method for the desired probes.     

EPR spectroscopy reveals nanoinhomogeneities in the structure and reactivity of thermoresponsive hydrogels

The dynamic and chemical behavior of solute molecules inside new thermoresponsive hydrogels (photocrosslinked poly(N-isopropylacrylamide) (pNiPAAm) copolymers) is studied by continuous-wave electron paramagnetic resonance spectroscopy. Via addition of paramagnetic tracer molecules (so-called spin probes) a picture is obtained of the thermally induced collapse on the molecular scale, which proceeds over a substantially broader temperature range than indicated by the sharp macroscopic volume transition. The sampling of hydrophilic and hydrophobic environments suggests a discontinuous collapse mechanism with a coexistence of collapsed and expanded network regions. These structural inhomogeneities on the nanoscale also lead to an inhomogeneity in chemical reactivity. The hydrophilic regions form nanoreactors, which strongly accelerate the reaction while the hydrophobic regions act as nanoshelters, in which enclosed spin probes are protected from the decay. The results show that the system consisting of a statistical binary or tertiary copolymer displays remarkably complex behavior that mimics spatial and chemical inhomogeneities observed in functional biopolymers such as enzymes.     

Evaluation of Flat Surface Temperature Probes

The objective of this paper is elaboration of elements related to metrological analysis in the field of surface temperature measurement. Surface temperature measurements are applicable in many fields. As examples, safety testing of electrical appliances and a pharmaceutical production line represent case studies for surface temperature measurements. In both cases correctness of the result of the surface temperature has an influence on final product safety and quality and thus conformity with specifications. This paper deals with the differences of flat surface temperature probes in measuring the surface temperature. For the purpose of safety testing of electrical appliances, surface temperature measurements are very important for safety of the user. General requirements are presented in European standards, which support requirements in European directives, e.g., European Low Voltage Directive 2006/95/EC and pharmaceutical requirements, which are introduced in official state legislation. This paper introduces a comparison of temperature measurements of an attached thermocouple on the measured surface and measurement with flat surface temperature probes. As a heat generator, a so called temperature artifact is used. It consists of an aluminum plate with an incorporated electrical heating element with very good temperature stability in the central part. The probes and thermocouple were applied with different forces to the surface in horizontal and vertical positions. The reference temperature was measured by a J-type fine-wire (0.2 mm) thermocouple. Two probes were homemade according to requirements in the European standard EN 60335-2-9/A12, one with a fine-wire (0.2 mm) thermocouple and one with 0.5mm of thermocouple wire diameter. Additional commercially available probes were compared. Differences between probes due to thermal conditions caused by application of the probe were found. Therefore, it can happen that measurements are performed with improper equipment or in an improper way for a particular application. Therefore, knowledge and awareness regarding all facts related to the used measuring equipment are essential to avoid the risk of a wrong decision on safety measures.     

Application of constant temperature anemometry in measurement of intra-arterial blood flow velocity

Considerations relevant to the application of constant temperature hot-film anemometry to measurement of point blood velocity in arteries are discussed. Hot-film probes suitable for intra-arterial use have been constructed and tested in regimes of steady and unsteady flow in both water and blood. Suitable calibration procedures have been established, and measurement errors due to system frequencyresponse distortion minimised by means of a simple filter. Errors due to fluid dynamic effects have been measured and analysed. A technique for detecting flow-reversal is described, and results obtained in preliminary animal experiments presented.     

超声处理对建筑用EVM表面离子镀DLC涂层组织和摩擦性的影响

通过超声方法处理聚氨基甲酸酯表面,选择脉冲碳离子源,结合阴极放电等离子方法在EVM表面完成DLC涂层的沉积过程,对超声处理过程中温度与时间参数引起的DLC涂层摩擦特性改变进行分析.实验测试研究结果表明:当超声处理的时间延长或者温度升高后,在试样表面形成了更深的条纹,能够显著增强EVM表面发生溶解的能力.DLC涂层在拉曼...