其他检测

The wakes of wall mounted circular cylinders of very low aspect ratio have been investigated in a wind tunnel. Besides planar PIV, also high resolution tomographic PIV was used to capture the flow phenomena downstream of the cylinder. By changing the velocity U￥ and the cylinder height h at a constant aspect ratio L = h=D, a wide database of different flow conditions was obtained. The resulting relative height of the boundary layer thickness d was 0:6  h=d  2:5, while the Reynolds number based on the length l between leading edge and cylinder centre Rel was 57;000  Rel  188; 000. A pair of counter-rotating vortices was found in the wake of the cylinder. The rotation sense is such, that in the center of the wake a positive vertical velocity component results. Also horseshoe vortices were found next to these trailing vortices. The relative height of the incoming boundary layer has a large impact on the development, strength and dissipation of the vortex system.

产品优势 ■ 更低的运营成本 ■ 降低了对氦气的依赖性，更少受限于国际市场波动对氦气供应的影响 ■ 系统独立操作，独立于连接的检漏系统 ■ 氦气资源的回收利用符合环境保护法规（例如，DIN EN ISO14001） ■ 全自动操作 ■ 连接的检测系统能自动排空检测物体 典型应用 ■ 汽车行业（如安全气囊、铝圈、燃料系统部件、空调系统部件和空气悬架系统) ■ 制冷技术(如蒸发设备、压缩机） ■ 真空和超压技术(如连接件） ■ 包装技术(如药剂制品和食品） ■ 能源技术（如中压开关设备、过电压吸收器） ■ 研发设备和实验室 ■ 加速器

We introduce and test an experimental approach to simulate elastoplastic megathrust earthquake cycles using an analogue model and apply it to study the seismotectonic evolution of subduction zones. The quasi-two-dimensional analogue model features rate- and state-dependent elastic-frictional plastic and viscoelastic material properties and is scaled for gravity, inertia, elasticity, friction, and viscosity. The experiments are monitored with a high-resolution strain analysis tool based on digital image correlation (particle imaging velocimetry, PIV), providing deformation time series comparable to seismologic, geodetic, and geologic observations. In order to separate elastic and nonelastic effects inherent the experimental deformation patterns, we integrate elastic dislocation modeling (EDM) into a hybrid approach: we use the analogue earthquake slip and interseismic locking distribution as EDM dislocation input and forward model the coseismic and interseismic elastic response. The residual, which remains when the EDM prediction is subtracted from the experimental deformation pattern, highlights the accumulation of permanent deformation in the model. The setup generates analogue earthquake sequences with realistic source mechanisms and elastic forearc response and recurrence patterns and reproduces principal earthquake scaling relations. By applying the model to an accretionary-type plate margin, we demonstrate how strain localization at the rupture peripheries may lead to a seismotectonically segmented forearc, including a tectonically stable shelf and coastal high (<20% plate convergence accommodated by internal shortening) overlying the area of large megathrust earthquake slip. Fifty to 75% of plate convergence is accommodated by internal shortening in the slope region where earthquake slip tapers out toward the trench. The inner forearc region remains undeformed and represents a basin.

Refrigerated air curtains are used in supermarket display cases to keep warm ambient air from entering the refrigerator case. Entrainment of ambient air into the curtain by shear layer mixing contributes to both the sensible and the latent heat load on the cases. In order to reduce this entrainment, a closer look at the air curtain is undertaken here. Particle Image Velocimetry was used to examine idealized air curtains of various Reynolds and Richardson numbers. The air curtain entrainment was seen to be dominated by eddies that engulfed ambient air into the air curtain. For the isothermal (Ri=0) curtains, it was observed that the air curtain dynamics and entrainment were not sensitive to Reynolds number variation between Re=3800 and Re=8500. At low air velocities (Re=1500), the curtain was found to detach, leading to extremely high entrainment rates. Variations in Richardson number of the curtain affected the flow at the curtain inlet most dramatically, where the acceleration of gravity caused the curtain to neck inwards. The overall thermal entrainment was shown to reduce with reducing Reynolds number, implying that a reduction in air curtain entrainment could be achieved by reducing the air velocity of the curtain, as long as air curtain integrity is maintained.

掌握滴高法测定铺展系数的原理，测定水、甘油等液体在石蜡，聚乙烯膜、聚酯膜等表面上的铺展系数；依同法计算不同浓度表面活性剂溶液在聚乙烯膜表面上的铺展系数，并讨论表面活性剂及其浓度对铺展系数的影响。

An ongoing research ramjet program initiated at ONERA under support of DGA (French ministry of Defence) aims to improve methodology for ramjet combustion chamber design and tuning by using validated CFD codes. A transparent model rig was used for aerodynamic tests with air flows at atmospheric pressure and room temperature. In the case of the simulation of a Solid Ducted Rocket (SDR) combustor, two fuel holes were located at the head end of the combustor in order to simulate the fuel supply from the auxiliary gas generator in the case of a real combustor. Among the various mechanisms that are controlling the development of the combustion processes inside the combustor, the mixing is certainly one of the most crucial as far as stability or efficiency are concerned. The work presented in this paper is addressing the characterization, in absence of combustion, of the turbulent flow velocity and scalar fields associated to the mixing between fuel (simulated by CO2) and air. Particle image velocimetry (PIV) and gas sampling analysis are the two techniques that were used to serve that purpose. Results presented in this paper are very useful to assess the ability of numerical computations, based either on Reynolds-Averaged Navier-Stokes (RANS) or Large-Eddy Simulations (LES) approaches, to reliably predict velocity and fuel concentration fields inside this research combustor.

本文通过对石墨炉原子吸收分光光度计工作原理、工艺操作及仪器维护保养等 方面的说明, 分析影响石墨管使用寿命的主要因素, 找到了解决问题的途径, 改善了仪器的测试条件和延长石墨管使用寿命, 达到了减少损耗, 节约检测成本的目的。

摘要：我作为东西电子的一名实验技术人员，通过本文来为使用东西电子原子吸收仪器的用户具体介绍几种常见的样品前处理方法，以及各种方法适用的样品类型，希望可以让使用者参考借鉴，来体现我们东西电子的员工，对客户的热心服务。 关键词：非完全消化法，酸消解法，微波消解法，悬浮液进样技术 引言：原子吸收光谱法具有灵敏、快速、选择性高、操作方便等优点，现在被广泛地应用于化工、石油、医药、冶金、地质、食品、生化及环境监测等领域，能测定几乎所有的金属及某些非金属元素。虽然用石墨炉法可以采用程序升温直接分析固体样品但干扰较大，用火焰原子吸收法时，样品要被吸喷雾化后才能被分析，为了使测量的结果有代表性，必须要保证样品均匀的分布在溶液中。所以有许多样品必须要经过前处理才能拿来测定，而不同的样品有不同的前处理方法，同一样品也有多种的前处理方法，选择不同方法的依据就是方便快捷、同时又要尽量减少样品的用量，减少有效成分的流失。样品处理是原子吸收光谱法测定的关键步骤之一，寻找简便有效的样品处理技术，一直是分析工作者的研究的重要课题，在这里我分别列举各种方法，说出它们各自的适用范围，并引用前人分析常见样品的方法为例让大家借鉴参考。

本方案能让平常只能在常温下观察样品和实验的显微镜，增加样品温控的功能。这样有几个好处： 【一】成本低。在显微镜上多加个冷热台就能做显微镜样品温控实验，相当于一个温控显微镜； 【二】技术权威。Instec冷热台控温好，-190℃~1500℃上下通吃，稳定性不差于0.05℃。而且功能多，能气密腔能真空腔，能移动样品还能通电。这是出自美国名校科罗拉多大学的Instec其30年经验历史保证； 【三】实验效率高。通用冷热台独特的侧边送样装填设计，能为研究者节省实验步骤。提高实验效率。 并且，Instec本来就生产液晶研究仪器，液晶相关设备功能强大，而且和温控设备都能有很好的搭配设计。

In this study, four different volume reconstruction techniques for tomographic PIV are investigated using synthetic and experimental data at different particle densities. Multiplied line of sight (MLOS) and Minimum line of sight (MinLOS) represent methods that need significant less computation time than the standard MART reconstruction. Motion Tracking Enhancement (MTE) on the other hand needs significant more computational time, but has the potential to achieve more accurate results especially at higher seeding densities. The presented results confirm that the fast MLOS and MinLOS reconstruction are applicable at low seeding densities of about 0.02 particles per pixel (ppp), and achieve a lower accuracy than standard MART. MTE on the other hand is proven to be applicable in the broadest density range from 0.01 ppp up to 0.2 ppp.

Agilent 1290 Infinity II 制备型 Open-Bed 馏分收集器为高效灵活地进行馏分收集树立了新标杆。馏分床可单独配备 6 个容器，容纳 8 种不同尺寸的馏分管。三个抽屉让您即使在运行期间也能轻松获取已收集的馏分。基于峰和时间的馏分模式已扩展至八种组合模式，能对体积或时间片段进行收集，且包括两种回收收集模式。紫外 (UV) 和质量选择检测 (MSD) 信号的触发组合现包含一个 AND/OR 逻辑算符，为挑战性纯化提供了额外的灵活性。本技术概述将提供馏分模式（包括收集结果）更深层次的介绍以及典型应用示例。

When air is blown from a slot directly upstream of a flap, the flow over the flap can bear large adverse pressure gradients without separation. This effect is used to design high-lift airfoils with low momentum coefficients of blowing. For experimental assessment of these airfoils a rectangular wing with an aspect ratio of 4.3 was built. The flow around the model in a low speed wind tunnel is analysed using pressure measurements and long distance microscopic particle image velocimetry. To measure the velocity in the vicinity of the slot and next to the surface of the flap the jet is seeded with particles. For Reynolds numbers of about Re = 1 · 106 the dimensionless momentum coefficient of the jet and the angle of attack of the airfoil are varied. Numerical simulations of the three-dimensional flow around the circulation control airfoil in the wind tunnel are compared to the experimental data. Good agreement is observed in terms of pressure distributions and velocity profiles.

A high level of fluorescence background signal rejection was achieved for solid and powder samples by using a combination of simple low-resolution spectrograph and ultrafast gated charge coupled device ~CCD! camera. The unique timing characteristics of the CCD camera match exceptionally well to characteristics of a Ti:sapphire oscillator allowing fast gated light detection at a repetition rate of up to 110 MHz, making this approach superior in terms of the duty cycle in comparison with other time-resolved Raman techniques. The achieved temporal resolution was about 150 ps under 785 nm Ti: sapphire laser excitation. At an average excitation power up to 300 mW there was no noticeable sample damage observed. Hence, the demonstrated approach extends the capabilities of Raman spectroscopy regarding the investigation of samples with a short fluorescence lifetime. The combination of a spectrometer and a gated CCD camera allows simultaneous study of spectral and temporal characteristics of emitted light. This capability opens an exciting possibility to build a universal instrument for solving multitask problems in applied laser spectroscopy

Low-frequency combustion instabilities were studied experimentally in a model lean-premixed stepped combustor. The PLIF technique was used to characterize the flame structure. The PIV technique, associated with high-speed visualization of the OH* radical chemiluminescence’s emission, allowed to investigate the flow field during the quasi-periodic unsteady flashback when the flame lifted from the edge of the step and moved periodically in and out of the premixing duct. Results strongly suggest that impact of acoustic waves on the flame structure should be taken into account when applying LES approach to industrial gas turbines.

在使用扫描电镜过程中，通常需要对晶相样品的几何尺寸进行测量及统计， TESCAN的颗粒度分析软件可以很好的解决客户的上述应用。

This paper presents observations and analysis of the time-dependent behaviour of a 10 kW partially pre-mixed, swirl stabilized methane-air flame exhibiting self-excited thermo-acoustic oscillations. This analysis is based on a series of measurements wherein particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) of the OH radical were performed simultaneously at 5 kHz repetition rate over durations of 0.8s. Chemiluminescence imaging of the OH* radical was performed separately, also at 5 kHz over 0.8s acquisition runs. These measurements were of sufficient sampling frequency and duration to extract usable spatial and temporal frequency information on the medium to large-scale flow-field and heat-release characteristics of the flame. This analysis is used to more fully characterize the interaction between the self-excited thermo-acoustic oscillations and the dominant flowfield structure of this flame, a precessing vortex core (PVC) present in the inner recirculation zone. Interpretation of individual measurement sequences yielded insight into various physical phenomena and the underlying mechanisms driving flame dynamics. It is observed for this flame that location of the reaction zone tracks large-scale fluctuations in axial velocity and also conforms to the passage of large-scale vortical structures through the flow-field. Local extinction of the reaction zone in regions of persistently high principal compressive strain is observed. Such extinctions, however, are seen to be self healing and thus do not induce blow-out. Indications of auto-ignition in regions of unburned gas near the exit are also observed. Probable auto-ignition events are frequently observed coincident with the centers of large-scale vortical structures, suggesting the phenomenon is linked to the enhanced mixing and longer residence times associated with fluid at the core of the PVC as it moves through the flame.

Ellipsometry is a very versatile optical technique that has applications in many different fields, from the micro electronics and semiconductor industries (for characterizing oxides or photoresists on silicon wafers, for ex ample) to biology. This very sensitive measurement technique provides unequalled capabilities for thin film metrology, and has the advantage that it is non-destructive as it uses polarized light to probe the dielectr properties of a sample.

生物炭（Biochar）具有特殊的表面化学性质（如富含含氧官能团）、结构属性（如多孔、较大的比表面积）以及内在成分（如矿物成分），因此它通常被当作吸附剂或稳定剂广泛应用于水处理和土壤修复等领域。

市场上的测色仪、色差仪品牌型号繁多，客户自身的产品也千差万别，测量目的和需要也尽不同，那么如何选择合适的测色仪、色差仪结构及型号呢？ 本文通过十个步骤帮助客户选择适合自己的测色仪或色差仪，避免了选择困难和失误。

台式扫描电子显微镜所具有高分辨观察功能，操作简易及无需前处理即可观察样品特点，使其非常适合进行科普教育工作。普通大众可以通过观察日常生活中物品切身体验微观世界，推动科学技术的运用和发展。

Forces on flapping or rotating wings, like flapping wings of micro air vehicles or blades of wind turbines are of great interest to engineers. To investigate the ways birds and insects fly, forces created by flapping wings are of importance to biologists. The pressure field, combined with the velocity field, gives a complete description of the (incompressible) flow dynamics. Furthermore the pressure field is the main contributor to the aerodynamic loading of bodies immersed in the fluid. Traditional techniques to determine pressure and forces rely on the determination of surface pressure and integral loads by point pressure and force balance measurements. In situations where it is difficult (or impossible) to instrument the body, using particle image velocimetry (PIV) velocity data to determine forces and pressure poses an interesting alternative to the existing approaches to determine sectional loading.

卤族元素指周期系ⅦA族元素，包括氟（F）、氯（Cl）、溴（Br）、碘（I）、砹（At）、Uus，简称卤素。除人工合成元素At、Uus外，其他卤素广泛应用于电子电路、聚合物材料、阻燃剂等领域。

Reliable and easy - to - use instrumentation for compound identification as well as purity checking are required during drug discovery and development. The Agilent 6120B Single Quadrupole hardware and software are ideal to support Walkup LC/MS methods for analyzing small molecules and biomolecules in a multi - user environment. A simp lified software interface combined with robust hardware gives nonexpert users the confidence to perform high quality and reliable LC/MS analysis. Agilent MassHunter Walkup Software provides automated email reports, which allows the user to receive the r esults in an organized manner at their desk. This Application Note discusses key hardware and software features of the 6120B Single Quadrupole Walkup system, and its practical use for applications including the analysis of chemic al libraries

准确性高 时间短LC-10A:双泵、二级管阵列检测器、7725I进样阀??原装工作站，LC-6A液相：6A泵一台??示差检测器??7725I进样阀??

Electrostatic, rotating bell (ESRB) application is one of the most important coating application techniques for industries with demanding specifications for optical attractiveness of coatings, such as automotive. The ESRB process involves production of droplets using a high-speed rotating bell, which are subsequently transported to the substrate being coated via shaping air [1-3]. An electrical potential is applied between the bell and the substrate which further helps droplet atomization and transport. This research investigates the effects of inertia, centrifugal force, drag force, and electrostatic force on the atomization mechanism and particle size distribution using an automotive OEM base coat formulation. Coating flow rate (CFR), shaping air flow rate (SAFR), bell speed (BS), and electrostatic potential (EP) were used as primary parameters to create various atomization conditions and particle size distributions. The atomization mechanism, ligament formation, and particle size distribution were measured using high-speed laser shadowography and image processing. The effects of governing forces and particle size generated on efficiency of droplet transfer to the substrate and optical appearance of the coatings were studied to generate operating windows for optimum process efficiency and appearance.

The spatial and temporal development of turbulent boundary layer flows is governed by the self-organization of coherent structures like hairpin-like or arch vortices and spanwise alternating wall bounded low- and highspeed streaks. For a detailed analysis of the topologies of the wall normal fluid exchange namely of the four quadrants of the instantaneous Reynolds stresses Q1,…,Q4 a 4D- measurement technique is desired. In this feasibility study the tomographic PIV technique (Elsinga et al. 2005) has been applied to time resolved PIV recordings. Four high speed CMOS cameras are imaging tracer particles which were illuminated in a volume inside a boundary layer flow at 4 kHz by using two high repetitive Nd:YAG pulse lasers. The instantaneously acquired single particle images of these cameras have been used for a three dimensional tomographic reconstruction of the light intensity distribution of the particle images in a volume of voxels (volume elements) virtually representing the measurement volume. Each of two subsequently acquired and reconstructed particle image distributions are cross-correlated in small interrogation volumes using iterative multi-grid schemes with volume-deformation in order to determine a time series of instantaneous 3D-3C velocity vector fields.

目前，电子显微镜技术(electron microscopy)已成为研究机体微细结构的重要手段。常用的有透射电镜 (transmission electron microscope，TEM)和扫描电子显微镜 (scanning electron microscope,SEM)。与光镜相比电镜用电子束代替了可见光，用电磁透镜代替了光学透镜并使用荧光屏将肉眼不可见电子束成像。

屈服应力是指破坏样品内部结构，使其由静止状态转变为流动状态的最小作用力。在流变学中，屈服应力是剪切应力的临界值。只有当剪切应力超过屈服点之后，材料才能发生流动；应力低于屈服点时，材料表现为弹性体，外力撤销后，材料能重构其内部结构。 屈服应力是许多实际应用中的一个重要流变参数，在材料的生产过程、装备的优化设计、材料的施工和使用等方面扮演重要的角色。它用于描述充填过程中分散性、凝胶稳定性、泵送行为、挤出行为等。通常情况下，屈服应力并不是一个常数，其结果与测试方法、数据处理方法等相关。 利用AMETEK Brookfield RSO震荡流变仪，可以有多种的测试方法对不同材料的屈服应力进行测试，满足不同行业的应用需求。

气凝胶具有极低的固态热传导，以及气态热传导，在常温常压下热导率可以低至0.013W/(m?K)，是所有固态材料中隔热性能好的一种。 利用TC3010测量得到的气凝胶粉末导热系数，从结果来看，不同工艺下样品的导热系数差异还是比较明显的。

利用微量热计Micro DSC芋对重金属离子影响脲酶催化水解反应的过程进行研究, 并探讨重金属离子联合抑制作用对脲酶催化反应的影响. 结果表明, 在25 益下, 重金属离子对脲酶水解反应热有影响, 在广泛浓度范围(0郾1, 1, 10, 100 和103 mg/ L)内, 这种影响不仅表现在抑制作用方面, 而且会促进其水解反应的进行, 如铜离子在100 和1000 mg/ L 时抑制率分别为(0郾49依0郾20)% 和(-11郾93依1郾34)%. 重金属离子浓度与抑制率具有显著或极显著的相关性, 抑制效果的顺序为砷离子>铅离子>镉离子>铜离子. 当重金属离子联合抑制时, 其抑制效果与抑制率较高的重金属离子的抑制作用接近.