基于单片机的远程光纤通信在点对点安全验证系统上的应用

现有的点对点安全验证系统都是基于电缆连接实现系统信息传输的。电缆传输信号存在传输衰减大、抗干扰能力差、在雷暴天气易发生事故等缺点。通过将基于单片机89C2051的远程光纤通信应用到现有设备来改进控制信号的传输模式，将电信号转换为光信号，在数据传输中使用传输同步码加密、数据包CRC校验、串行数据编码以及光纤连通性定时自动监测等技术，可以从物理信号传输到数据接收处理的整个过程中保证系统的安全性和可靠性；同时，通过光纤通信方案，也能节省系统构建和维护的经费。     

一种综合颜色、纹理信息的皮肤检测方法

针对目前许多皮肤检测方法只考虑了像素级别上的颜色信息，未较好地利用图像空间上的其他信息，如纹理信息以及光照条件对成像颜色所造成的影响，在SPM方法的基础上提出了改进。首先引入“灰色世界”算法对因非标准光照所产生的颜色改变进行校正，有效提高了正检率。对SPM方法的输出部分通过灰度共生矩阵提取图像的纹理信息，过滤颜色信息为皮肤而纹理信息为非皮肤的像素区域，有效降低了误检率。实验结果表明，该方法取得了较好的效果。     

大空间钢结构建筑消防安全评估研究

大空间钢结构建筑发生火灾时,火焰及火灾产生的高温羽流可能对钢构件构成一定威胁。采用经验公式计算和FDS模拟分析两种方法计算火灾环境中大空间建筑钢构件的温度,评估钢构件是否达到或超过其失效温度。     

Modeling and solution for the ship stowage planning problem of coils in the steel industry

We consider a ship stowage planning problem where steel coils with known destination ports are to be loaded onto a ship. The coils are to be stowed on the ship in rows. Due to their heavy weight and cylindrical shape, coils can be stowed in at most two levels. Different from stowage problems in previous studies, in this problem there are no fixed positions on the ship for the coils due to their different sizes. At a destination port, if a coil to be unloaded is not at a top position, those blocking it need to be shuffled. In addition, the stability of ship has to be maintained after unloading at each destination port. The objective for the stowage planning problem is to minimize a combination of ship instability throughout the entire voyage, the shuffles needed for unloading at the destination ports, and the dispersion of coils to be unloaded at the same destination port. We formulate the problem as a novel mixed integer linear programming model. Several valid inequalities are derived to help reducing solution time. A tabu search (TS) algorithm is developed for the problem with the initial solution generated using a construction heuristic. To evaluate the proposed TS algorithm, numerical experiments are carried out on problem instances of three different scales by comparing it with a model‐based decomposition heuristic, the classic TS algorithm, the particle swarm optimization algorithm, and the manual method used in practice. The results show that for small problems, the proposed algorithm can generate optimal solutions. For medium and large practical problems, the proposed algorithm outperforms other methods. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 564–581, 2015     

Optimization of process parameters of the activated tungsten inert gas welding for aspect ratio of UNS S32205 duplex stainless steel welds

The activated TIG (ATIG) welding process mainly focuses on increasing the depth of penetration and the reduction in the width of weld bead has not been paid much attention. The shape of a weld in terms of its width-to-depth ratio known as aspect ratio has a marked influence on its solidification cracking tendency. The major influencing ATIG welding parameters, such as electrode gap, travel speed, current and voltage, that aid in controlling the aspect ratio of DSS joints, must be optimized to obtain desirable aspect ratio for DSS joints. Hence in this study, the above parameters of ATIG welding for aspect ratio of ASTM/UNS S32205 DSS welds are optimized by using Taguchi orthogonal array (OA) experimental design and other statistical tools such as Analysis of Variance (ANOVA) and Pooled ANOVA techniques. The optimum process parameters are found to be 1 mm electrode gap, 130 mm/min travel speed, 140 A current and 12 V voltage. The aspect ratio and the ferrite content for the DSS joints fabricated using the optimized ATIG parameters are found to be well within the acceptable range and there is no macroscopically evident solidification cracking.     

Feasibility of surface-coated friction stir welding tools to join AISI 304 grade austenitic stainless steel

An attempt is made to develop the tools that are capable enough to withstand the shear, impact and thermal forces that occur during friction stir welding of stainless steels. The atmospheric plasma spray and plasma transferred arc hardfacing processes are employed to deposit refractory ceramic based composite coatings on the Inconel 738 alloy. Five different combinations of self-fluxing alloy powder and 60% ceramic reinforcement particulate mixtures are used for coating. The best friction stir welding tool selected based on tool wear analysis is used to fabricate the austenitic stainless steel joints.     

Effect of welding processes and consumables on fatigue crack growth behaviour of armour grade quenched and tempered steel joints

Quenched and Tempered (Q&T) steels are widely used in the construction of military vehicles due to its high strength to weight ratio and high hardness. These steels are prone to hydrogen induced cracking (HIC) in the heat affected zone (HAZ) after welding. The use of austenitic stainless steel (ASS) consumables to weld the above steel was the only available remedy because of higher solubility for hydrogen in austenitic phase. The use of stainless steel consumables for a non-stainless steel base metal is not economical. Hence, alternate consumables for welding Q&T steels and their vulnerability to HIC need to be explored. Recent studies proved that low hydrogen ferritic steel (LHF) consumables can be used to weld Q&T steels, which can give very low hydrogen levels in the weld deposits. The use of ASS and LHF consumables will lead to distinct microstructures in their respective welds. This microstructural heterogeneity will have a drastic influence in the fatigue crack growth resistance of armour grade Q&T steel welds. Hence, in this investigation an attempt has been made to study the influence of welding consumables and welding processes on fatigue crack growth behaviour of armour grade Q&T Steel joints. Shielded metal arc welding (SMAW) and Flux cored arc welding (FCAW) were used for fabrication of joints using ASS and LHF consumables. The joints fabricated by SMAW process using LHF consumable exhibited superior fatigue crack growth resistance than all other joints.     

Neural network modeling to evaluate the dynamic flow stress of high strength armor steels under high strain rate compression

An artificial neural network (ANN) constitutive model is developed for high strength armor steel tempered at 500 °C, 600 °C and 650 °C based on high strain rate data generated from split Hopkinson pressure bar (SHPB) experiments. A new neural network configuration consisting of both training and validation is effectively employed to predict flow stress. Tempering temperature, strain rate and strain are considered as inputs, whereas flow stress is taken as output of the neural network. A comparative study on Johnson–Cook (J–C) model and neural network model is performed. It was observed that the developed neural network model could predict flow stress under various strain rates and tempering temperatures. The experimental stress–strain data obtained from high strain rate compression tests using SHPB, over a range of tempering temperatures (500–650 °C), strains (0.05–0.2) and strain rates (1000–5500/s) are employed to formulate J–C model to predict the high strain rate deformation behavior of high strength armor steels. The J-C model and the back-propagation ANN model were developed to predict the high strain rate deformation behavior of high strength armor steel and their predictability is evaluated in terms of correlation coefficient (R) and average absolute relative error (AARE). R and AARE for the J–C model are found to be 0.7461 and 27.624%, respectively, while R and AARE for the ANN model are 0.9995 and 2.58%, respectively. It was observed that the predictions by ANN model are in consistence with the experimental data for all tempering temperatures.     

电子探针在电气火灾物证技术鉴定中的应用

在介绍电子探针分析技术的功能和特点的基础上,结合火灾案例说明了电子探针技术在导线熔痕电子显微形貌观察及熔痕微孔表层成分分析中的应用.通过分析,从导线短路熔痕的微观形貌、熔痕孔洞表层的特征元素含量中获得其熔痕形成原因,进而为火灾调查提供技术支持.     

刑事法律制度差异对海峡两岸合作打击跨境犯罪的影响及对策研究

大陆地区和台湾地区的刑事法律制度存在较大差异,必将影响海峡两岸共同合作打击跨境犯罪工作的开展。海峡两岸应在《海峡两岸共同打击犯罪及司法互助协议》框架下,在协商互信的基础上,本着对两岸刑事法律制度差异的清晰认识,采取合理、有效的刑事对策弱化其对两岸合作打击跨境犯罪的影响。