细水雾作用下烟颗粒形貌及尺寸变化规律研究

利用Sirion200型场发射扫描电子显微镜拍摄细水雾作用前后柴油和聚氯乙烯(PVC)材料烟颗粒的形貌和内部结构图像。定义了烟颗粒的采样平均直径(dA)和表面密度(ρS),利用统计分析的方法计算了细水雾作用前后烟颗粒的dA和ρS,研究了采样点空间位置、细水雾工作压力、雾滴粒径和雾滴速度等因素对dA和ρS的影响规律,揭示了细水雾冲刷火灾烟颗粒的主导机理,为细水雾技术用于计算机房等电气环境的火灾烟气抑制提供了科学的参考依据。     

旋芯直径对喷嘴雾化特性的影响

针对现有旋芯需要高压雾化的问题,设计一种低压下能达到同等雾化性能的旋芯喷嘴,利用激光多普勒粒子分析仪测试不同旋芯直径和流道直径时距离喷嘴1 m处雾滴的中位直径、速度和雾锥角。结果表明:当水压为0.9~1.2 MPa时,喷嘴所形成的雾滴的中位直径均小于100μm,说明了旋芯喷嘴改进的合理性;旋芯直径越大,雾滴的中位直径和速度越小,雾锥角越大。     

管道内水雾对冲击波衰减作用的实验研究

采用直径200 mm立式激波管,进行了管道内水雾对冲击波衰减作用的实验研究.实验结果表明,冲击波衰减率与水雾密度、雾滴直径和雾区厚度有关.相同雾滴直径时,水雾密度越大,冲击波的衰减率越大相同水雾密度时,水雾的雾滴直径越小,冲击波的衰减率越大.     

基于Hartmann哨超声喷嘴的雾化特性研究

介绍了一种基于Hartmann哨的超声雾化喷嘴。通过激光粒度分析仪对喷嘴的雾化特性进行了实验研究,分析了不同气压对雾滴索特平均直径(SMD)、雾化角和用水量的影响。对喷嘴加装了中心杆,对比了有无中心杆对于雾滴SMD的影响。研究表明:随着气压的增大,雾滴SMD显著减小,雾化角增大,而气压在0.5 MPa时两者达到极值并趋于稳定;喷嘴加入中心杆,并在气压达到一定值后,雾滴SMD有了明显的减小,最小雾滴SMD可以达到12μm;在气压为0.5 MPa,用水量最少,雾化效果最佳。     

切向旋流式雾化喷嘴流场的仿真和实验研究

旋流引入喷嘴不仅能够提高液体动能,也能提高雾化效果。为了理清切向旋流式雾化喷嘴的内外流场特性,通过数值计算研究了内流场的压力和速度分布,通过实验测试分析了不同参数(旋流通道直径、旋流室直径、射流水压)下的外流场分布。结果表明:旋流室上部中心区域会在旋流力与惯性作用下发生螺旋运动,产生明显压力梯度,导致负压形成。旋流明显地提高了喷嘴内部水流的速度,喷嘴轴线的速率也随口径增大而上升。随着射流水压的增加,雾滴D50表现出明显的减小趋势。雾滴D50随旋流室直径增大表现出先单调减小的变化,雾滴速度随旋流通道直径增大先增大后缓慢减小的变化,确定最佳旋流室直径3 cm,旋流通道直径为3 mm。     

SU16型喷嘴雾化性能仿真分析

喷嘴的雾化效果在个人防护用具的化学雾滴防护性能检测中起了重要作用。文章利用FLUENT商业软件对空气辅助雾化喷嘴的喷雾场进行了模拟求解,讨论了喷嘴的结构及气流流速对液滴平均直径离散数量分布的影响。通过对喷嘴仿真结果的分析和对其结构优化,为提高空气辅助雾化喷嘴的质量提供了有效的改善方法。     

基于图像运动模型的航空遥感影像快速匹配算法

随着航空遥感视频影像应用得越来越广泛,对影像的配准速度和精度的要求也越来越高.本文利用视频影像连续重叠度大的特征,对图像进行二次配准处理,利用图像的运动估计模型,经过粗匹配和精匹配两次配准实现视频序列帧间时空配准.实验结果表明,改进的算法不仅提高配准精度,同时还提高了运算速度满足对视频图像实时处理的要求.     

指针式压力表自动计量校准系统

目前,指针式压力表常采用影像法进行计量校准,但在计量过程中存在压力表指针难分割、背景难分离和识别准确率低等问题,为解决上述问题,结合不同规格压力表表盘的外观尺寸,对压力表自动计量校准系统进行研究。首先,根据工业相机视野范围内压力表表盘外形尺寸,自动判断相机与压力表之间最佳工作距离;其次,利用图像边缘梯度值评价图像清晰度,自动完成相机对焦;最后,采用极坐标转换方法实现刻度线定位、指针提取、实时读数等功能。测试结果表明,该系统适用于外壳直径为40,60,100,150,200,250 mm的指针式压力表计量校准。     

基于图像色貌模型的高动态影像显示技术研究

目的研究高动态影像(HDR)在低动态范围显示设备上的高保真显示问题。方法采用图像色貌模型(iCAM)设计高动态影像的再现技术框架,并使用C++语言搭建软件实现系统,通过计算机测试平台对输入图片进行了实证,算法重点是处理影像的明视度。结果显示图像的动态范围被拓展10%以上,色差小于1.6ΔE*ab,图像细节得到了加强,基本达到了高动态影像高保真显示的要求。结论可利用iCAM框架来实现高动态影像在常规显示设备上高保真显示的问题,具有重要的理论意义与技术价值。     

激光衍射小直径的CCD测量

介绍了一种利用激光衍射的原理测量小直径的方法。它是采用线阵CCD器件接收激光衍射图像，由8098单片机进行数据采集、处理与计算，从而实现了小直径细丝的直径在线测量。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.