服务器受冲击过程竖插扩展卡应变仿真分析

服务器在运输过程中有受到较大冲击力的风险,故研发阶段对服务器进行一定程度的冲击测试。首先,分析服务器冲击测试过程中PCI扩展卡强度较差的应变试验数据,再借助仿真分析方法,对比分析多种扩展卡加强固定方案,比较单一方案及组合方案的效果差异,选择最优方案配置。通过仿真对比分析多种加强固定方案可知,采用组合方案最为稳妥。     

A fast color image enhancement algorithm based on Max Intensity Channel

In this paper, we extend image enhancement techniques based on the retinex theory imitating human visual perception of scenes containing high illumination variations. This extension achieves simultaneous dynamic range modification, color consistency, and lightness rendition without multi-scale Gaussian filtering which has a certain halo effect. The reflection component is analyzed based on the illumination and reflection imaging model. A new prior named Max Intensity Channel (MIC) is implemented assuming that the reflections of some points in the scene are very high in at least one color channel. Using this prior, the illumination of the scene is obtained directly by performing a gray-scale closing operation and a fast cross-bilateral filtering on the MIC of the input color image. Consequently, the reflection component of each RGB color channel can be determined from the illumination and reflection imaging model. The proposed algorithm estimates the illumination component which is relatively smooth and maintains the edge details in different regions. A satisfactory color rendition is achieved for a class of images that do not satisfy the gray-world assumption implicit to the theoretical foundation of the retinex. Experiments are carried out to compare the new method with several spatial and transform domain methods. Our results indicate that the new method is superior in enhancement applications, improves computation speed, and performs well for images with high illumination variations than other methods. Further comparisons of images from National Aeronautics and Space Administration and a wearable camera eButton have shown a high performance of the new method with better color restoration and preservation of image details.     

电容层析成像技术的研究进展与分析

电容层析成像(electrical capacitance tomography,ECT)技术是以医学CT技术为基础,伴随着计算机技术和传感器技术发展起来的一种过程层析成像技术。对ECT系统的各个组成单元和工程应用的研究成果进行分类,并逐类进行总结论述。比较了不同结构的电容传感器,并对传感器参数的优化方法进行总结。讨论了测量电容值的各种方法及其优劣性。在归纳主要图像重建算法及其改进方法的同时,还分析了典型算法的原理和流程。总结了ECT系统的各种主要工程应用和成功案例。在此基础上,指出了有待发展的若干研究课题及关键技术,并对某些发展方向予以展望。     

建筑产业集群类型与模式研究

根据当前建筑产业集群现象,研究建筑产业集群类型和模式。按照产业特点不同将建筑产业集群分为建筑施工集群、建筑设计集群、建筑装饰集群和建筑部品集群四种类型,并对它们的特点进行比较和探讨。根据形成原因的不同将建筑产业集群分为市场自发型和政府主导型两种模式,并对二者的形成机理进行分析,提出发展建筑产业集群的政策建议。     

基于自组织神经网络的建筑市场执业资格人员信用分类研究

利用自组织神经网络技术,结合建筑市场执业资格人员信用的相关特点,研究了网络中神经元个数的确定、训练步数、网络维数、获胜神经元的领域等对网络结构和执业资格人员信用划分类别的影响,给出了执业资格人员信用分类的网络构造思想和神经网络结构,并以被调查的执业资格人员为例进行了实证研究。研究结果表明,该方法简便、易行,适用于执业资格人员信用分类研究,为开展执业资格人员信用管理奠定了良好的理论方法基础。     

Glass-forming ability and soft magnetic properties of (Co0.6Fe0.3Ni0.1)67B22+xSi6−xNb5 bulk glassy alloys

The glass-forming ability (GFA) and soft-magnetic properties of (Co_0.6Fe_0.3Ni_0.1)₆₇B_22+xSi_6?xNb₅ (x = 0–1.5) bulk glassy alloys was investigated. The DSC curves show that the (Co_0.6Fe_0.3Ni_0.1)₆₇B_22+xSi_6?xNb₅ bulk glassy alloys have a wide supercooled liquid region (ΔT_x) of about 60 K, and high reduced glass transition temperature (T_g/T_l) lies in the range from 0.628 to 0.649. By copper mold casting method, the bulk glassy alloys with diameters up to 4.5 mm can be formed. In addition to high GFA, the Co-based bulk glassy alloys also exhibit good soft-magnetic properties, i.e., saturation magnetization of 0.58–0.61 T, low coercive force of 0.83–1.46 A/m, and high permeability of (1.79–2.2) × 10⁴ at 1 kHz under a field of 1 A/m. These Co-based bulk glassy alloys are promising for future applications as a new structural and functional material.     

Microstructure Evolution and Mechanical Behavior of Cold-Sprayed,Bulk Nanostructured Titanium

To provide insight into the microstructural evolution and mechanical behavior of bulk nanostructured Ti, we used cold gas dynamic spraying of Ti particles to synthesize thick coatings (e.g., >10 mm in thickness). Accordingly, the grain size, lattice parameter, lattice strain, residual stress, porosity, microhardness, tensile, and compressive behavior of the bulk Ti deposits before and after annealing were comparatively analyzed. Our results show that the microstructure of the as-sprayed bulk Ti was characterized by a grain size of ~60 nm, lattice expansion (~2 pct for \( a \) and ~3 pct for \( c \) ), lattice strain (~1.65 × 10^?5), and residual compressive stress (~53 MPa). Moreover, annealing of the as-deposited bulk Ti led to a significant decrease in lattice expansion, lattice strain, and residual stress, whereas porosity remained unchanged (~11 pct). The mechanisms of grain growth, as well as the evolution of particle interfaces during annealing, were also investigated. In terms of mechanical behavior, the as-deposited bulk Ti exhibited a very low modulus (52 GPa) with relatively high tensile and compressive strength values (180 and 850 MPa, respectively). Annealing in the temperature range of 1023 K to 1173 K (750 °C to 900 °C) led to a significant increase of tensile and compressive strength (to 380 MPa and more than 1200 MPa, respectively). Finally, annealing resulted in a slight increase of elastic modulus, which was rationalized on the basis of changes in pore geometry in the bulk Ti deposits.     

Multi-index optimization design for electrical resistance tomography sensor

A multiple index optimization method for ERT sensors is put forward which combines an orthogonal design and fuzzy analysis. This method first establishes a scientific and proper fuzzy evaluation method using fuzzy mathematics to define ERT index satisfaction (ERTIS) and overall ERT index satisfaction (OERTIS) and to construct their satisfaction functions. It unifies all of ERT sensor indices into a single comparable satisfaction value. Then, the OERTIS analysis is developed which allows a set of multiple index orthogonal experiments to be transferred into a single index orthogonal experiment. Where, the uniformity index and the correlation coefficient index of the ERT sensor are set as the optimization objectives. The experiments are set up based on multi-index orthogonal design. The experimental results indicate that the method can derive an evenly distributed sensitivity field and a better image with the optimized sensors, and improve the OERTIS of the ERT sensors by 13.75%.     

Numerical analysis on the effects of refrigerant injection on the scroll compressor

Refrigerant injection is an effective method to improve the performance of the scroll compressor and its system under high compression ratio working conditions. This paper intends to find the exhaustive relationship between the injection parameters and the compressor’s performance. Based on a thermodynamic model, the effects of various parameters of refrigerant injection on general performance and inner compression process of scroll compressor have been investigated. As a result, it is found that the injected scroll compressor will get the maximum indicated efficiency when the ratio of inner compression ratio and outer compression ratio is a right value. The right value is 1 for the isentropic compression process, and smaller than 1 for a real compression process. Finally, the effects of all the injection factors on the compression work, refrigerant mass flow rate, p–h diagram, volumetric efficiency, and indicated efficiency are investigated detailedly.