其他检测

卡尔费休水分测定法，已被很多国际标准，如ISO，ASTM，DIN，BS，和JIS等公认为准确性最高的方法，适用于各种物质水分含量的测定，是目前最值得信赖的水分分析测量仪器，应用范围广泛，适用于固体、液体和气体样品。 通过本试验验证AKF-2010利用纯水标定的准确度与重复性。

In the present work the process of a transient fuel injection in a constant high-pressure atmosphere is investigated experimentally. As fuel, dimethyl ether (DME) is used. The goal is to receive new information about the charac-teristics referring to the droplet size, the droplet velocity and the droplet shape in the jet. The high-pressure chamber has a constant pressure of 2 MPa and the fuel spray is injected with a pressure of 6 MPa, 7 MPa and 8 MPa. The spray is analysed by a Shadow-Sizing-technique and digital image analysis with temporal and spatial resolution, which even allows investigating non-spherical droplets. The correlations of d velocity and droplet shape are presented as Joint Probability Density Functions (JPDF). The conclusion of the investigation shows that little increase of the injection pressure has a remarkable effect on the droplet size. Furthermore, the centricity is widely influenced by the injection pressure. With lower injection pressure the droplet velocity decreases. Moreover, the droplets mean diameter shows a significant decrease with increasing time after the injection

In particle image velocimetry (PIV) a temporally separated image pair of a gas or liquid seeded with small particles is recorded and analysed in order to measure fluid flows therein. We investigate a variational approach to cross-correlation, a robust and well-established method to determine displacement vectors from the image data. A “soft” Gaussian window function replaces the usual rectangular correlation frame. We propose a criterion to adapt the window size and shape that directly formulates the goal to minimise the displacement estimation error. In order to measure motion and adapt the window shapes at the same time we combine both sub-problems into a bi-level optimisation problem and solve it via continuous multiscale methods. Experiments with synthetic and real PIV data demonstrate the ability of our approach to solve the formulated problem. Moreover window adaptation yields significantly improved results.

Stemi 508采用复消色差变焦光学系统并将杂散光减少到最低，从而获得更加清晰的3D图像，即便在很小的放大倍数下仍然无失真、无彩色条纹。充分利用8:1的超大变倍比获得更加丰富的组织细节和锐利的图像。根据您的工作需要选择正确的前端透镜和目镜，可实现在2倍到250倍之间倍率自由选择，在获得双倍的分辨率的同时，更可获得高达286mm的超大工作距离。

A new method to describe small scale statistical information from passive scalar fields has been proposed by Wang and Peters (2006). They used direct numerical simulations (DNS) of homogeneous shear flow to introduce the innovative concept. This novel method determines the local minimum and maximum points of a fluctuating scalar field via gradient trajectories starting from every grid point in the direction of the steepest ascending and descending scalar gradients. Relying on gradient trajectories, a dissipation element is defined as the region of all the grid points the trajectories of which share the same pair of maximum and minimum points. The procedure has also been successfully applied to various DNS fields of homogeneous shear turbulence using the three velocity components and the kinetic energy as scalar fields. To validate statistical properties of these elements derived from DNS (Wang and Peters 2006, 2008), dissipation elements are for the first time determined based on experimental data of a fully developed turbulent channel flow. The dissipation elements are deduced from the gradients of the instantaneous fluctuation of the three velocity components u5, v5, and w5 and the instantaneous kinetic energy k5, respectively. The required 3D velocity data is obtained investigating a 17.82 × 17.82 × 2.7 mm3 (0.356
× 0.356
× 0.054
) test volume using tomographic particle-image velocimetry (Tomo-PIV). The measurements are conducted at a Reynolds number of 1.7× 104 based on the channel half-height
and the bulk velocity U. Detection and analysis of dissipation elements from the experimental velocity data are presented. The statistical results are compared to the DNS data from Wang and Peters (2006, 2008).

超声波是一种频率高于20000赫兹的声波，它的方向性好，穿透能力强，易于获得较集中的声能，在水中传播距离远，可用于测距、测速、清洗、焊接、碎石、杀菌消毒等。在医学、军事、工业、农业上有很多的应用。

GC/MS 维护是在样品分析过程中保留分析目标的普遍要求。快速柱内反吹是 GC/MS 维护过程中的一次重要改进，能够改善离子源并延长 GC 使用寿命，并在不放真空的情况下快速完成气相色谱柱和进样口维护。另外，消除污染离子源的后洗脱组分已成为压力控制三通配置的突出特点。通过这些改进，离子源清洁频率显著降低，但是仍然需要进行清洁。冷却仪器、从分析 仪中取出离子源、机械清洁离子源、更换离子源、重新抽真空以及对分析仪 进行重新调谐和调节以改善系统灵敏度，整个过程可能需要操作人员花费大量的时间。Agilent JetClean 智氢洁离子源能够将冷却、取出、手动清洁、更换和抽真空等步骤替换为原位过程，从而节省了时间，减轻了操作人员的负担。为除去积聚的物质并恢复离子源性能，智氢洁离子源处理中形成的氢类 物质改变了离子源内部的条件。本应用简报介绍了智氢洁离子源的两种操作方法。

脉冲激光沉积（Pulsed Laser Deposition, PLD），是一种利用激光对物体进行轰击，然后将轰击出来的物质沉淀在不同的衬底上, 得到沉淀或者薄膜的一种手段. PLD 系统由多个真空腔体组成，整个系统需要超高真空且不能引入任何杂质，对环境的清洁度要求较高，必须配备无油干泵和分子泵抽真空。由于各个辅助腔体体积较小, 因此特别适合使用 pfeiffer Hicube 系列分子泵组. 伯东公司销售维修的 Pfeiffer 分子泵组因其结构紧凑体积小，清洁无油（前级泵配备干泵）、抽速快、极限真空度高达10-11mbar等优点一经上市好评如潮。

To understand and optimize the combustion processes in new types of internal combustion engines, like gasoline direct-injection engines, non-intrusive laser-based diagnostics methods have proven to be versatile and important tools to measure combustion characteristics. Most engine developers already rely on optical methods in the development of new engines. To guarantee accurate and reliable results of optical measurements it is necessary to carefully evaluate and characterize these techniques under realistic conditions. In this work a variety of laser-based diagnostics techniques, mostly based on the tracer- LIF principle, have been evaluated for their applicability and limitations and have been applied to different spray systems – reaching from single droplets, over model sprays to fuel sprays in a firing test engine. The tracer-laser-induced-fluorescence (LIF) method is based on doping the fuel with a fluorescent substance whose fluorescence characteristics are used to measure various physical properties of the spray, such as temperature, droplet size, or droplet velocity. From these properties information about heat and mass-transfer mechanisms in the spray can be gained. However, the characteristics of the used tracers must be known in detail in order to guarantee useful and comparable results. Therefore, in this work various tracers were characterized in terms of their evaporation and temperaturedependent properties. The tracers Atto 680, Rhodamine 800 and Rhodamine B have further been tested for their applicability to realistic fuels.

样品池结露对粒度测试有这么大的危害，如果我们在发现测试过程或测试结果异常才去处理，将可能出现错误的结果，提供错误的信息，带来重大的损失。为此百特在激光粒度仪中安装了露点温度监测系统，这在国内外激光粒度仪中首次采用此项技术。该系统实时监测仪器运行环境的温度、湿度以及用介质温度，并将温湿度数据实时传输到电脑中用来监测露点温度，一是用来指导用户通过控制介质温度来使样品池远离露点温度，使测试结果准确有效。二是当发生样品池结露现象时，电脑系统会自动报警提示，以方便用户提高介质温度，消除结露现象

Over centuries, the classical optical microscope was the only tool that provided researchers images behind the limits defined by their eyes. During the last century light microscopy went through a tremendous development. But the basic idea of a lens or a set of lenses enlarging a reflective or transmitive image and making it visible to the eye of the viewer remained. Today, light microscopy shows a vast variety of different techniques. On the one hand, the classical light microscopy has been refined by additional contrast enhancing techniques. On the other hand, a complete new field of light microscopy has been established: the fluorescence microscopy. Here, the sample is excited to emit fluorescence light. Manipulating the excitation light and analyzing the emission light offers new ways of obtaining information about the often specifically prepared sample. This thesis deals mainly with a new way of excitation in fluorescence microscopy: the two-color two-photon (2c2p) excitation. For the first time femtosecond laser pulses are used to excite fluorescence by simultaneous absorption of two photons of different wavelengths.

处理数据时，分析员往往面临显示过多或不足的数据，无法有效地分析样品。这导致在打开和 关闭数据文件、元数据以及相关报告时耗时过长。将屏幕上的窗格与色谱图和/ 或所选的进样 链接，Thermo ScientificTM DionexTM ChromeleonTM 7.2 色谱数据系统（CDS）软件向分析员提 供处理数据所需的所有相关信息，从而使数据分析更快速、更简便。

本文介绍了一种在室温附近测试各种量块和其它相似形状材料的高精度热膨胀系数测试仪器的研究开发。量块热膨胀所引起的长度变形通过一个差分平面镜干涉仪进行测量，采用特殊的干涉相位检测技术来补偿极化混合带来的非线性误差，再结合电子相位计可以实现纳米量级的精度。由于是在真空中进行量块热膨胀测量，从而无需进行空气折射率补偿。对于导热系数较高的被测试样，缓慢的辐射热交换使得试样上的温度梯度很小并具有很好的热平衡稳定性。在所获得典型的10～30℃温度之间热膨胀测试曲线，其线性和二次方热膨胀系数都等于在20℃参考温度时的热膨胀系数。本文对此激光干涉法热膨胀仪的测量不确定进行了详细分析，而且此测量不确定度也通过国际比对得到了验证。

Vertical slot fish passes have been applied as a solution to mitigate fish migration problems in running waters, for over two decades. They are commonly used to enable target fish to ascend through obstacles in rivers. However, small species are rarely considered in such fishways, of which the performance for small fish still remains unknown. This experiment was to study the turbulence structure in a vertical slot fish pass concerning two different pool length/width ratios of 9 and 6.67 as well as the effect of installing a cylinder behind the slot in affecting the characteristics of instationary flow. Cylinders are considered an effective solution to modify the flow structure and to reduce velocity and turbulent energy in order to adapt the flow for the passage of small fish species. Flow visualization and particle image velocimetry were used to study the characteristics of mean flow and turbulence and particular emphasis on the unsteady flow. The results show that flow patterns consist of a water jet and one or two recirculation zones depending on the length/width ratio of the pool. The direction of the jet was strongly affected by the vertical cylinders. The frequencies and spatio-temporal evolutions of the main jet beats were analyzed. Combining with the previous studies of fish migration experiments, the results provide hydraulic evidence on the biological performance.

Proper Orthogonal Decomposition (P.O.D.) is a technique used for analysis of vortex structures in a turbulent flow. In this study, complex shear flows are observed by P.I.V. measurements (Particle Image Velocimetry) of a large diameter ratio annular jet. The annular jet is an example of complex shear flow situations. Two axisymmetric shear layers, originating at the jet exit, one at the nozzle lip and the other at the centre body, eventually meet downstream or interact with each other. The main aim of this study is to observe and analyze the effects of active control using acoustic waves on an annular jet with a great diameter ratio (r= 0.91), in order to find a new way to reduce jet instabilities. This contribution discusses the application of Proper Orthogonal Decomposition to the P.I.V. (Particle Image Velocimetry) velocity fields of an annular jet and on a statistic of time resolved tomographic images of the initial zone of the annular jet. Acoustic waves are then applied on the annular jet with different frequencies (fundamental, first harmonic̷). Measurements are conducted with a Reynolds number ReDo=107800. The fluctuation frequency of the stagnation point is known for this Reynolds number. The Strouhal number corresponding to this frequency is StDo = 0.27. The P.O.D. analysis applied on a natural annular jet and an excited annular jet enables us to see the importance of the triggering of the acoustic wave with the stagnation point motion. An active control is therefore necessary to use acoustic excitation to reduce instabilities in the initial zone of these turbulent jets. Active control has already been used with round jets and has given promising results, but only a few studies have been conducted on annular jets in this field. This work will permit us essentially to have a better knowledge of annular jets and to meet manufacturers' needs.

采用热分析 (TG、DTG、DSC)技术，进行不同升温速率(10℃/min ，,20℃/min ，30℃/min)下碳气化反热分析研究。结果表明：在线性升温条件下，碳气化反应分为反应放热的缓慢阶段和吸热的快速阶段。慢速气化阶段呈现放热的原因是CO2 在固体碳表面发生吸附作用热大于气化反应热。通过Coats-Redffen 法求解动力学参数，得出慢速和快速气化阶段的活化能分别为65.68～33.38 kJ·mol和159.26 ～105.58kJ·mol，并随升温速率的提高而降低。

Flow past a cylinder in an unbound medium gives rise to self-sustained, limit cycle oscillations involving formation of a regular, periodically alternating Karman vortex street. However, little attention has been paid to the effect of an adjacent free surface on the development of the Karman vortices and possible generation of new classes of the nearwake structure[1], see Figure 1. The technique of Particle Image Velocimetry (PIV) is a useful tool to this flow, considering that it is unsteady and multi-scale in nature.

The paper presents results of strain measurements in cohesionless sand in two different boundary value problems, namely quasi-static pull-out test of a steel wall and confined granular flow in a rectangular model silo using a non-destructive method called Particle Image Velocimetry (PIV) which is a technique for measuring surface displacements from digital images. Advantages and disadvantages of the method are outlined.

Active flow control earns growing interest for manufacturers of large transport aircraft because of the constant need to improve these aircraft in terms of less fuel consumption, higher efficiency, steep approaches and departures and less weight. Flow control devices that are based on fluidic actuators, e.g. vortex generator jets (VGJs), have shown a promising potential to influence separating boundary layers and keep them attached (e.g. Godard & Stanislas (2006a‐c); Johari. & Rixon (2003); Johnston & Nishi (1990); Mc Manus et al. (1996); Ortmanns et al. (2008a); Pauley & Eaton (1988); Scholz et al. (2006)). For an efficient operation such devices need to be optimized regarding their ability to influence the flow. However, optimization turns out to be very challenging because of the vast parameter space and the lack of an adequate “figure of merit”. The proposed contribution will discuss the possibility to assess and optimize such devices by analyzing the velocity fields from stereoscopic PIV measurements.

The flow generated by heat convection in a long, vertical channel is studied by means of particle imagery velocimetry techniques, with the help of the thermal measurements from a previous paper (Gibert et al 2009 Phys. Fluids 21 035109). We analyse the mean velocity profiles and the Reynolds stresses, and compare the present results with the previous ones obtained in a larger cell and at a larger Reynolds number.We calculate the horizontal temperature profile and the related horizontal heat flux. The pertinence of effective turbulent diffusivity and viscosity is confirmed by the low value of the associated mixing length. We study the one-point and two-point statistics of both velocity components. We show how the concept of turbulent viscosity explains the relations between the local probability density functions (pdf) of fluctuations for temperature, vertical and horizontal velocity components. Despite the low Reynolds number values explored, some conclusions can be drawn about the small scale velocity differences and the related energy cascade. 4 Author

At atmospheric pressure (AP)ions are subject to a high frequency of collisions with bulk gas particles and other species present.Due to the high number of collisions,even relatively slow chemical reactions may become relevant in an AP ion source.The length of the ion migration path is directly correlated with the absolute number of collisions, therefore it may serve as a figure of merit to estimate the relevance of individual chemical interactions. In addition the experimental investigation of ion transfer times allows the verification of complex numerical models, which consider transport due to electrical fields and viscous gas flow.

The Tomographic-PIV measurement system performances are experimentally assessed within the present study. The technique is applied to the turbulent air flow past circular cylinders in two configurations, namely the thin light sheet and the thick light sheet. In the first case the Tomo-PIV measurements are compared with stereoscopic PIV, which is assumed as a reference result. Image signal conditioning by pre-processing seems to be essential in order to achieve an accurate particle field reconstruction in presence of background light and electronic noise. The comparison shows that the two techniques are basically equivalent in the thin light sheet configuration. The 3D measurements are performed with the thick light sheet technique where the instantaneous velocity vector distribution is measured over a domain of 31x26x10 mm3 yielding 28x24x5 velocity vectors. The vortex wake past a circular section cylinder is visualized within the volume snapshots and the time-averaged flow representation shows a consistent flow pattern with respect to the geometric boundary conditions with the separated shear layers aligned along the cylinder axis.

介绍不同实验最适宜用哪个级别的水，恰当的选择适宜的用水级别，不仅可以合理的满足实验的要求，同时也可以降低制水的成本，因为超纯水的制取成本要远高于纯水的制取，同时介绍了如何从自来水生产出超纯水等内容。

近些年来，纳米颗粒材料被越来越广泛的应用于衣食住行等各领域内，由此带来的潜在的纳米颗粒污染问题，逐渐引起了人们的重视。单颗粒电感耦合等离子体质谱（spICP-MS）技术是近年来发展起来的可用于进行纳米颗粒表征的方法。使用此方法，可实现一次进样同时完成颗粒粒径、数量浓度、元素含量及粒径分布的分 析。

通过宏观检验、化学成分分析、金相检验、硬度测试、扫描电镜以及能谱分析等方法，对某减速机齿轮断裂原因进行了分析。结果表明，齿轮断裂为接触疲劳断裂，主要是由于断裂部位存在夹渣缺陷。

We present the results of a combined experimental and numerical study of the generation of internal waves using the novel internal wave generator design of Gostiaux et al. (Exp. Fluids, vol. 42, 2007, pp. 123–130). This mechanism, which involves a tunable source composed of oscillating plates, has so far been used for a few fundamental studies of internal waves, but its full potential is yet to be realized. Our study reveals that this approach is capable of producing a wide variety of twodimensional wave fields, including plane waves, wave beams and discrete vertical modes in finite-depth stratifications. The effects of discretization by a finite number of plates, forcing amplitude and angle of propagation are investigated, and it is found that the method is remarkably efficient at generating a complete wave field despite forcing only one velocity component in a controllable manner. We furthermore find that the nature of the radiated wave field is well predicted using Fourier transforms of the spatial structure of the wave generator.

The unsteady organization and temporal dynamics of the interaction between a planar shock wave impinging on a turbulent boundary layer at a free stream Mach number of M∞=1.69 is investigated experimentally by means of dual-plane Particle Image Velocimetry (dual-PIV). Two independent PIV systems were combined in two component mode to obtain instantaneous velocity fields separated by a prescribed small time delay. This enables to obtain, in addition to mean and statistical flow properties, also instantaneously time resolved data to characterize the temporal dynamics of the flow phenomenon in terms of time scales, temporal correlations and convective velocities. The characteristic time scales for the incoming boundary layer, the separation region and the reflected shock are evaluated by means of measuring the temporal auto-correlation coefficient in the complete flow field for a range of time delays from 5 ms to 2000 ms. These auto-correlation fields are used to quantify the time scales in selected regions of the flow. This permits resolving the dominant time scales within the boundary layer and the interaction region. I. Introduction

加热磁力搅拌器是实验室常用的加热仪器。需要加热的时候，我们通常有两种要求：第一是温度精度高；第二是要求加热速度很快。

通过ESCALAB Xi+设备对玻纤增强聚对苯二甲酸丁二醇复合材料（PBT）进行常规XPS+XPI 表征分析，探索玻璃纤维在PBT 表面微区的面内分布情况及化学态组成信息，这些信息能为研究人员进一步提升此类材料性能提供指导和帮助。通过本案例的讲解主要是为了展示XPS 成像功能在材料表面分析中也能发挥较大的作用。这种常规XPS 测试+XPI 的全新解决方案为科研分析助力。

理化室经常使用的各种玻璃器具是否干净，常常影响到分析结果的可靠性与准确性，所以保证所使用的玻璃器具干净是非常重要的。 洗涤玻璃器具的方法很多，应根据试验的要求、污物的性质和污染的程度来选用。需准确量取溶液的量器，清洗时不易使用毛刷，因长时间使用毛刷，容易磨损量器内壁，使量取的物质不准确。 玻璃器洁净度检查：内壁应完全被水润湿而不挂水珠。