移动电源起火原因分析及使用中应注意的几个问题

近年来,移动电源起火爆炸事故频发。在介绍移动电源结构和工作原理的基础上,总结了移动电源起火爆炸的主要原因,提出了移动电源在使用过程中应注意的几个问题,为移动电源的安全使用提供了建议。     

扫描电镜分析法在电动自行车火灾成因鉴定中的应用

由电动自行车引发的火灾中,电动自行车起火原因的调查是非常重要的。由于电动自行车采用各种直流电池作为电源,因而与交流电条件下的各种电气火灾调查鉴定有所不同。在直流电源条件下多股铜导线的短路熔痕的形态特征与普通交流电条件下形成短路熔痕的形态特征存在一定的差异。运用扫描电子显微镜,通过对多股铜导线在直流电条件下一次短路熔痕,过载熔断时所形成的熔断表面及熔珠进行分析研究。通过微观形态的观察,可以区分一次短路或过载熔断。     

贯彻强军目标 创设良好思想政治工作环境

强军目标是新时期军队建设的行动纲领。思想政治建设必须围绕强军目标展开。军队思想政治工作受所处环境的影响和制约。贯彻强军目标创设良好的思想政治工作环境,首先要从本单位自身做起,建设净化优美的军营“小环境”,塑造军营环境的“奋斗之关”“陶冶之美”“形象之美”,增强思想政治工作环境的推动力、感染力和约束力。     

舰艇编队协同反导队形配置优化研究

随着舰艇编队网络中心作战模式的产生与发展,其队形配置问题必须重新给予考虑。首先介绍了网络化反导作战系统的远程数据作战能力;其后,从指挥通信、火力掩护和一次耦合杀伤区3个方面给出舰舰间距的约束条件,以远程数据作战条件下编队舰空导弹杀伤区增量最大为优化目标,建立编队舰舰间距优化模型,并在此基础上结合电子干扰的要求,给出了编队队列角的最优范围解算方法;最后,在一定的战场假设下,通过示例的方式对模型的有效性与适应性进行了验证。     

Assessing the value of demand sharing in supply chains

We consider the problem of assessing the value of demand sharing in a multistage supply chain in which the retailer observes stationary autoregressive moving average demand with Gaussian white noise (shocks). Similar to previous research, we assume each supply chain player constructs its best linear forecast of the leadtime demand and uses it to determine the order quantity via a periodic review myopic order‐up‐to policy. We demonstrate how a typical supply chain player can determine the extent of its available information in the presence of demand sharing by studying the properties of the moving average polynomials of adjacent supply chain players. The retailer's demand is driven by the random shocks appearing in the autoregressive moving average representation for its demand. Under the assumptions we will make in this article, to the retailer, knowing the shock information is equivalent to knowing the demand process (assuming that the model parameters are also known). Thus (in the event of sharing) the retailer's demand sequence and shock sequence would contain the same information to the retailer's supplier. We will show that, once we consider the dynamics of demand propagation further up the chain, it may be that a player's demand and shock sequences will contain different levels of information for an upstream player. Hence, we study how a player can determine its available information under demand sharing, and use this information to forecast leadtime demand. We characterize the value of demand sharing for a typical supply chain player. Furthermore, we show conditions under which (i) it is equivalent to no sharing, (ii) it is equivalent to full information shock sharing, and (iii) it is intermediate in value to the two previously described arrangements. Although it follows from existing literature that demand sharing is equivalent to full information shock sharing between a retailer and supplier, we demonstrate and characterize when this result does not generalize to upstream supply chain players. We then show that demand propagates through a supply chain where any player may share nothing, its demand, or its full information shocks (FIS) with an adjacent upstream player as quasi‐ARMA in—quasi‐ARMA out. We also provide a convenient form for the propagation of demand in a supply chain that will lend itself to future research applications. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 515–531, 2014     

多态的大功率可控硅开关功率放大器的仿真

为了满足远距离海底探测对发射信号大功率的需求,选用了一种大功率可控硅开关功率放大器。在临界换流、自然换流和强迫换流3种工作状态下,分析了该功率放大器的工作原理,并建立了等效电路模型。运用Or CAD仿真了临界换流状态时的等效电路模型;在自然换流状态和强迫换流状态下,为获得功放电流值和负载电流值,对其等效电路模型分别建立了非线性数学模型,并通过Matlab和VC++采用四阶Runge-Kutta法对非线性数学模型进行求解。以上方法能够求得该功率放大器电路在任意时刻、任意点处的电流电压值,能较客观、真实地反映电路的工作状况,对工程应用具有一定的参考价值。     

MONEY IN SOUTHERN AFRICAN POLITICS

“Lack of money is the root of all evil”

George Bernard Shaw

In a environment where party financing, private funding in particular, is generally a laissez-faire business, as in most Southern African countries, there is the real risk that interest groups and wealthy individuals will buy influence in political parties and in so doing erode public confidence in the political system. Because they are neither open to public scrutiny nor subject to any legislative restraints, huge private donations can, and often do, come with strings attached. This lack of transparency and openness, as well as mechanisms to prevent it, provides ample ground for influence peddling, where those who pay the piper call the tune. Left unchecked, this party funding scenario will continue to be a serious indictment of the region's democratisation projects, crippling democracy and stunting economic development. This article consid     

ATOMS FOR PEACE

Atomic Assistance: How “Atoms for Peace” Programs Cause Nuclear Insecurity, by Matthew Fuhrmann, Cornell University Press, 2012, 344 pages, $29.95.     

Nuclear Subsidies and Proliferation: Clarifying the Link

ABSTRACT

In March 2015, the South Australian state government established a royal commission to investigate the financial, social, technical, diplomatic, and nonproliferation benefits and risks of expanding its nuclear industry, including activities related to uranium mining; enriching, reprocessing, and fabricating nuclear fuels for both domestic use and export; producing nuclear power; and storing radiological waste, including foreign spent reactor fuel. Given its enormous uranium reserves and current mining activities, some Australians have argued that Australia could benefit financially by expanding the mining sector and by adding value to its uranium exports by enriching the material and fabricating it into reactor fuel assemblies. Others have maintained that Australia can realize significant economic benefits by recycling and storing foreign spent fuel and producing carbon-free nuclear power. In the end, the commission recommended that Australia consider opening up a high-level waste repository to take in foreign spent fuel. It did not recommend any other nuclear activities at this time. The following viewpoint is based on testimony I delivered to the commission on the nuclear weapon proliferation implications of the proposed activities. If Australia wants to avoid the temptation of selling nuclear goods to states that might use these goods to make bombs, it should only consider new nuclear activities that can be entirely financed by the private sector and turn a profit without having to resort to foreign sales. This policy would also enable Australia to set an important, new international nonproliferation standard.     

基于DPA的LED非线性部件逆向研究

在军事和商业应用中有很多密码算法是半公开或者不公开的,旨在证明算法保密对密码的安全性提高并没有明显帮助．针对轻型分组密码LED的未知非线性部件S盒,提出了一种基于差分功耗分析的逆向方法,该方法可以利用差分功耗曲线的极性信息来恢复未知算法结构．实验结果表明,在LED的S盒参数未知时,利用功耗采集平台采集算法运行时泄露的旁路功耗信息,可以成功逆向出全部s盒信息,验证了该方法的可行性．