基于小波多尺度分解的互补全景图像融合

为了解决折反射成像内外环分辨率低且不均匀的问题,针对互补全景图像的特点,提出了一种基于小波多尺度分解的图像融合方法。首先对两幅互补的源图像分别进行小波多尺度分解,得到不同分辨率、不同方向的分量;其次,按照特定的融合策略,低频采用平均算子进行融合,高频采用逐层互换的融合策略进行融合;最后,通过小波逆变换得到融合图像。实验结果表明,该方法在互补全景图像的融合中简单有效,并且拥有较好的效果。     

Standardization of Tritium Water by TDCR Method

The triple-to-double coincidence ratio (TDCR) method of liquid scintillation count-ing is an absolute measurement method of radioactivity.The formulation of the TDCR method and the established TDCR liquid scintillation counter are presented in this paper.The NIST standard reference material (SRM) of tritium water was measured to verify the performance of the TDCR liquid scintillation counter.     

交叉吊索对超大跨CFRP主缆悬索桥颤振性能的改善作用

颤振一旦发生,将给桥梁结构带来毁灭性灾难,颤振稳定性是大跨桥梁重要的抗风控制指标。交叉吊索可显著提高超大跨悬索桥的扭转刚度,从而提高其颤振性能。该文以某主跨3500m的超大跨径CFRP（carbon fiber reinforced plastics）主缆悬索桥为工程背景,从频率和振型两方面分析了水平交叉吊索和竖向交叉吊索对其动力特性的影响,并绘制与颤振相关的弯频和扭频随交叉吊索设置位置的变化曲线（简称“影响曲线”）,进而针对提高结构颤振稳定性提出11种交叉吊索设置方案。基于耦合颤振的分步分析法,分析这11种方案的颤振稳定性。分析结果表明,在中跨满布水平交叉吊索的同时,在中跨L/3和边跨跨中各对称设置一对竖向交叉吊索,结构的颤振稳定性最好,颤振临界风速提高达49%。     

煤矿实景培训基地建设与探索

针对煤矿安全的“零容忍”而不愿意接纳涉煤专业学生生产实习,以及高校实习经费不足、实习内容简化、实习效果差等问题,本着优势互补、互利共赢原则,山西工程技术学院与山西省固庄煤矿共同建设了一座煤矿实景培训基地。通过该项目的实施,改善了校内实习实训条件,实现了采煤专业主干课程理论与实践教学实景化,融“教、学、做”为一体,教师的实践教学能力、学生的实践动手能力以及创新创业能力提升显著,并且为大批煤矿职工进行了技能鉴定,基地社会服务能力初见成效。     

基于ObjectARX实现零件的特征建模

针对AutoCAD系统在基于特征建模技术方面的不足,采用ObjectARX开发工具和面向对象技术,在AutoCAD2007平台上实现了零件的特征建模,具有用户界面友好、操作简单、设计效率高等优点,可以方便地输入特征的几何信息与非几何信息,为后续过程提供了丰富的信息,便于CAD与后续的CAPP和CAM集成,说明利用现有CAD系统的实体造型功能,开发特征建模系统是实现CAD/CAM集成的一种简单而有效的方法.     

Local stress around cap-like portions of anisotropically and nonuniformly grown oxide layer in thermal barrier coating system

The intrinsic deformation accompanying the growth of thermally grown oxide (TGO) can induce significant local stress potentially causing interfacial delamination and coatings fracture in a thermal barrier coating system (TBCs). Multiple mechanisms can be involved in a TGO growth process which is sensitive to the reactive elements contained in the coatings, and as a result anisotropic and nonuniform growth deformation can be produced in the TGO layer. The objective of this study is to analytically and numerically investigate the oxide-growth-induced local stress around the cap-like portions of a TGO layer having grown to a certain thickness and furthermore demonstrate the associated micro-crack patterns. A sphere model is proposed to analytically derive the elastic and elastic–plastic solutions of the stress field, which takes into account the anisotropy and nonuniformity of growth strain as well as the yielding of coating materials. On the other hand, finite element analysis is carried out to consider more realistic undulation morphology of the TGO layer and to verify the analytical prediction. It is seen that the through-thickness and lateral components of the anisotropic growth strain compete in the stress generation and there exist critical conditions for the dominance of different growth strains. The effect of growth strain gradient is examined to disclose the consequence of TGO dominant growth at the TGO/BC (bond coat) interface. The effects of the roughness and thickness of TGO and the plastic behaviour of different coating layers are also analysed. Finally, the possible micro-crack patterns due to TGO growth in typical TBC systems are illustrated with suggestions about how to reduce the driving force for the related structural failure.     

基于虚拟正交试验的Inconel690合金大口径厚壁管挤压工艺仿真

研究挤压成形参数影响规律并确定合理的参数取值范围,是开发难变形合金大型型材挤压工艺技术和挤压过程精细化控制,以及大吨位(如2万吨)挤压机的研发、调试及应用迫切需要开展的重要内容。基于DEFORM-2D平台,以规格为Ф420mm×60mm的难变形Inconel690合金管材穿孔针挤压为研究对象,建立了适用、可靠的无缝管材穿孔针挤压过程的有限元仿真模型;选取挤压比λ、模角α、定径带长度h、坯料初始温度T、挤压速度v等重要成形参数为影响因素,以坯料温度峰值Tmax、坯料金属损伤峰值Dmax、模口坯料金属流速均方差Fsdv和挤压力峰值Lmax为衡量指标,开展了基于模拟仿真的虚拟正交试验研究。结果表明,影响Tmax、Dmax、Fsdv、Lmax的因素主次顺序分别为:T>v>λ>h>α、α>v≈λ>T>h、h>v>T>α>λ、λ>T>α>v>h;综合考虑成形管材质量、挤压力等因素,获得了2万吨难变形合金卧式挤压机上挤压该规格Inconel690合金管材的合理成形参数取值范围为:λ=5.74～6.37、α=35～45°、h=60～120mm、T=1080～1180℃、v=150～250mm/s。     

我国现行辐射环境监测标准体系的缺项分析

建立完善的辐射环境监测标准体系,是制订《＂十二五＂全国辐射环境监测体系建设工作方案》的主要任务之一。现行国内辐射环境监测相关标准满足了我国辐射环境监测工作的基本需求。根据国家相关管理性法规标准,参照国内外最新的辐射环境监测相关标准和方法,查找出28项标准缺项。这些标准经过制定完善后,将形成一个结构基本完整的辐射环境监测标准体系。     

Multicomposition analysis and pattern recognition of Chinese geographical indication product: vinegar

Multicomposition fingerprints with several chemical compositions containing inorganic elements and organic compounds (amino acids, polyhydric alcohols, organic acids) were measured to distinguish two geographical indication-protected vinegars (GIs) from general vinegars (nGIs). The two of GIs were named Shanxi extra aged vinegar and Zhenjiang vinegar from Shanxi and Jiangsu province, respectively. Principal component analysis and Fisher linear discriminant methods were applied for the pattern recognition and classification of GI product. It was not suitable by simply using one kind of composition to make a distinction between GIs and nGIs. However, by using multicomposition to build a classify model, the classification of SXVs was described by Co, As, Al, Mg, Ca, erythritol, arabitol, sorbitol, proline, lysine and pyruvic acid, while ZJVs classification was described by threonine, serine, glycine, lysine, Ba, erythritol, xylitol and lactic acid. The GI samples can be classified with high accuracy according to the discriminant model, of which the false rate is 3.88 % in SXVs model and 10.85 % in ZJVs model. This method can be a useful method for protecting the geographical indication vinegars from the fake or adulterate vinegar commodities.     

Nano/micro lithium transitionmetal (Fe, Mn, Co and Ni) silicate cathode materials for lithium ion batteries

Lithium transitionmetal (Fe, Mn, Co, Ni) silicate cathode materials are new promising substituting cathode materials for lithium ion batteries. They had caught the researchers' eyes in the past several years. Nowadays, there are growing interests for silicate cathode materials in the field of lithium ion batteries. Among the silicate cathode materials, Li2FeSiO4 is the most promising cathode materials because of its high structure stability, high reversible capacity, high electronic conductivity and the abundant resource of iron and silicon. Although Li2MnSiO4 and Li2CoSiO4 have much higher theoretic specific capacity than Li2FeSiO4, they all have inferior electrochemical behaviours due to different reasons. There are only calculation results about Li2NiSiO4 till now. This brief critical review firstly discussed some papers about the first-principle calculation of Li2MSiO4 (M=Fe, Mn, Co Ni), and then collects and discusses relevant papers and recent patents about the fabrication, structure, particle size and electrochemical performance of nano/micro Li2MSiO4 (M=Fe, Mn, Co Ni) and their composites. Finally, the future challenges of Li2FeSiO4 are also discussed.