片体干扰对三体船附加质量和附加惯性矩的影响研究

基于三维Rankine源方法,进行三体船附加质量和附加惯性矩计算,分析了片体干扰对三体船附加质量和附加惯性矩的影响,为三体船操纵性预报奠定基础.通过对圆球、椭球附加质量和附加惯性矩的计算,以及对三体船附加质量和附加惯性矩定性规律的分析,说明了文中方法的可靠性.研究表明,片体干扰对三体船附加质量和附加惯性矩有一定影响,但并不十分明显,且这种影响随着间距的增大很快衰减.     

A NEW STANDARD FOR PREEMPTIVE MILITARY ACTION AGAINST WMD THREATS

International law clearly requires an imminent threat of attack as a justification for the preemptive use of military force. However, the standard definition of an imminent threat was derived centuries before the development of nuclear, chemical, or biological weapons or ballistic missiles and other delivery systems that can reach their targets in a matter of minutes. Any use of force to alleviate threats posed by weapons of mass destruction (WMD) prior to tactical warning of the actual launch of such weapons falls into the legally and ethically controversial category of “anticipatory self-defense,” leaving decision makers potentially liable to prosecution for war crimes. Effective and ethical enforcement of nonproliferation therefore demands a standard for imminence of threat broad enough to allow military action as a last resort but sufficiently restrictive to prohibit indiscriminate action against suspected WMD programs. Following a critical review of selected literature and cases on preemption, the author proposes a new standard for preemptive military action: the existence of operational WMD, or a clandestine program to develop WMD, in contravention of international law. The author discusses the implications of this new proposed standard, which at the time of writing would permit preemptive attack against WMD-armed terrorist groups but prohibit it against all states except Iran and possibly North Korea.     

Contents and Author Index,Volume 20, 2013

The United States has multiple nuclear detection initiatives to secure against a terrorist nuclear attack, including the Container Security Initiative, installation of radiation detectors at U.S. border points of entry, and establishment of the Domestic Nuclear Detection Office (DNDO). The current nuclear detection system architecture falls short of being able to reliably catch fissile nuclear material in transit, specifically shielded Highly Enriched Uranium (HEU) and Plutonium (Pu), both within the US and abroad. Checkpoints at border crossings can be circumvented, and no adequate system is under development to deter the transport of fissile materials. Using nuclear link-budget calculations, we show why a network relying primarily on handhelds, fixed detectors, and portals is not sufficient. We examine the technical, economic, and operational feasibility of a comprehensive national network incorporating in-vehicle detectors to reliably detect and deter the transport of fissile material inside the vehicle itself.     

INTERNATIONAL REGIME OF FRESH FUEL SUPPLY AND SPENT FUEL DISPOSAL

Recent events in Iran and elsewhere demand a reevaluation of the need for increasing nuclear fuel supplies and assuring reliable flow of fuel to nuclear power user states vis-à-vis the need for strengthened security for all countries against the use of weapons of mass destruction (WMD). The right of countries to a guaranteed supply of nuclear energy for peaceful uses must be balanced with the global community's desire to limit flows of nuclear material and sensitive nuclear facilities that could create opportunities for nuclear proliferation. This article proposes elements of an international regime of fresh fuel supply and spent fuel disposal that will guarantee fresh fuel supplies to countries honoring their obligations under the Treaty for the Non-Proliferation of Nuclear Weapons (NPT), while reducing concerns about diversion of spent fuel for weapons purposes. A specific application to countries with small pre-commercial uranium enrichment plants is also proposed.     

导频设计的MIMO-OFDM改进信道估计算法

为提高系统的传输效率并改善信道估计的性能,提出了一种结合优化导频设计的分段带阻滤波算法.采用优化的导频设计,该算法在少量增加计算复杂度的基础上,能够进一步提高信道估计的性能,与实际中广泛应用的经典时域滤波算法相比,具有更高的估计精度.仿真结果证明该算法适用于不同的信道环境,尤其在低信噪比的条件下,该算法能够明显降低信道估计的MSE.     

LDO稳压器敏感度建模与仿真技术

基于LDO稳压器在电磁干扰（EMI）下产生直流偏移失效的机理分析,展开敏感度建模与仿真方法研究。使用一款实验芯片,创新地引入片上电压传感器,用于测试EMI在LDO稳压器内部的传播特性。在敏感度建模中,建立等效电路模型,通过直流功能测试,Z参数阻抗特性测试验证模型的正确性,将该模型用于LDO稳压器的敏感度预测。在敏感度仿真过程中,通过分析关键子电路和不断增加寄生元件,仿真不同寄生因素对敏感度影响的权重。将仿真结果与传导直接注入法（DPI）片上测试结果对比,仿真结果与DPI测试在频域1MHz至1GHz匹配。     

Novel aluminum-based fuel: Facile preparation to improve thermal reactions

To improve the thermal properties of aluminum (Al) in the energetic system, a coated structure with ammonium perchlorate (AP) was prepared by a facile approach. And N, N-Dimethylformamide (DMF) was chosen as an ideal solvent based on heterogeneous nucleation theory and molecular dynamics simulation. This coated structure could enlarge the contact area and improve the reaction environment to enhance the thermal properties. The addition of AP could accelerate oxidation temperature of Al with around 17.5 °C. And the heat release of 85@15 composition rises to 26.13 kJ/g and the reaction degree is 97.6% with higher peak pressure (254.6 kPa) and rise rate (1.397 MPa/s). An ideal ratio with 15 wt% AP was probed primarily. The high energy laser-induced shockwave experiment was utilized to simulate the reaction behavior in hot field. And the larger activated mixture of coated powder could release more energy to promote the growth of shockwave with higher speed up to 518.7 ± 55.9 m/s. In conclusion, 85@15 composition is expected to be applied in energetic system as a novel metal fuel.     

瞬态高强加热条件下含湿多孔介质传热传质模型研究

提出了瞬态高强加热下含湿多孔介质传热传质的新模型,模型包括的水分种类齐全、水分迁移机制全面,假设条件相对较少,考虑了非Fourier传热效应和非Fick传质效应。新模型通过具体的分区分析得到简化并更加实用。     

FAE野外空中爆炸效应实验研究及其一次起爆机理探讨

野外进行1．8kg的FAE静爆实验,采用不同配方的纯固态燃料和液一固混合燃料与等质量的TNT对比分析。实验结果表明,FAE的爆炸效果明显优于等质量的TNT,而纯固态FAE爆炸性能强于液一固混合FAE;FAE爆炸后测到的超压分布呈现单调减趋势,这是由于测量点都分布在云爆区范围之外;FAE的云雾分散效果优于等质量的TNT装药,火焰持续时间也长。通过高速摄影图片看出,合适配方的纯固态无约束的FAE弹体火球的持续时间与有约束的液一固混合FAE弹体相当。分析了纯固态FAE爆炸后超压峰值时刻与火球最大直径时刻不同步的原因,探讨了纯固态FAE一次起爆机理。     

固体燃料冲压发动机飞行性能分析

固体燃料冲压发动机性能通过进气道与导弹飞行工况关联在一起,其工作过程需考虑导弹飞行参数对发动机性能的影响。与其它冲压发动机相比,固体燃料冲压发动机一个显著特点是推进剂燃烧过程不仅与推进剂配方、发动机结构和燃烧室压强有关,还取决于燃烧室入口空气参数,因此工作过程较为复杂。在国内首次建立固体燃料冲压发动机工作过程仿真模型,并分析导弹飞行马赫数和高度对发动机性能的影响规律。