关于层合板的混合能量原理及其应用

给出了关于层合板混合能量密度的一般形式及其对应的本构关系。建立了相应于这些能量密度的混合能量原理，并指出它们存在的优点。最后给出了原理的具体应用，数值计算表明本文的结果是可靠的。     

能量有限元预示复合材料结构动响应研究进展

复合材料结构高频动响应预示是飞行器等结构设计中的重要研究内容之一.为了探讨精确预示复合材料结构高频动响应方法,分析比较了目前较为通用的3种动力学响应预示方法,指出能量有限元法最适合求解具有各向异性特征的复合材料结构高频动响应问题.紧接着概述了国内外关于能量有限元方法和该方法在复合材料结构高频动响应预示方面的研究进展.在此基础上分析了能量有限元法在预示复合材料结构高频动响应问题中尚待深入研究的问题.     

高能量密度下的金

美国Lawrence Livermore实验室的科学家利用强激光将一小块金靶转换成由电子和正离子组成的等离子体．在金样品分飞之前的瞬间，物理学家记录到一些令人惊讶的结果．最重要的发现是：即使在高能量密度（10^7焦耳／千克）的极端条件下，金仍然保持所有金属所展示的能带结构一所容许的电子能量不是连续的而是处于一定的容许的能带中．     

Stable, efficient diode-pumped femtosecond Yb:KGW laser through optimization of energy density on SESAM

An efficient high-power diode-pumped femtosecond Yb:KGW laser is repored. Through optimization of energy density by semiconductor saturable absorber mirror, output power achieved 2.4 W with pulse duration of 350 fs and repetition rate of 53 MHz at a pump power of 12.5 W, corresponding to an optical-to-optical efficiency of 19.2%. We believe that it is the highest optical-to-optical efficiency for single-diode-pumped bulk Yb:KGW femtosecond lasers to date.     

福建物构所锂硫电池正极材料研究取得新进展

<正>锂硫电池的能量密度是目前商品化锂离子电池的3-5倍,同时硫具有成本低、环境友好、安全性能高等优点,能很好地满足未来动力电池的需要。然而在实际应用中,锂硫电池存在着硫的电导率低、放电过程中多硫化物的溶解以及充电过程中硫电极的体积膨胀等问题,这些问题导致硫正极的循环寿命短、容量衰减快以及能量效率低,从而限制了锂硫电池的实际应用。在科技部973计划、国家自然科学基金项目的支持下,     

Theoretical studies on a series of nitroaliphatic energetic compounds

Density functional theory calculations at the B3LYP/6-311G＊＊ level are performed to study the geometric and elec- tronic structures of a series of nitroaliphatic compounds. The heats of formation （HOF） are predicted through the designed isodesmic reactions. Thermal stabilities are evaluated via the homolytic bond dissociation energies （BDEs）. Further, the correlation is developed between impact sensitivity h50% and the ratio （BDE/E） of the weakest BDE to the total energy E containing zero point energy correction. In addition, the relative stability of the title compounds is evaluated based on the analysis of calculated Mulliken population and the energy gaps between the frontier orbitals. The calculated BDEs, HOFs, and energy gaps consistently indicate that compound 1,1,1,6,6,6-hexanitro-3-hexyne is the most unstable and the compound 3,3,4,4,-tetranitro-hexane is the most stable. These results provide basic information for the molecular design of novel high energetic density materials.     

Damage characteristics of HfO_2/SiO_2 high reflector at 45° incidence in 1-on-1 and N-on-1 tests

P-polarization high reflectors are deposited by e-beam from hafnia and silica. 1-on-1 and N-on-1 tests at 1064-nm wavelength with P-polarization at 45° incidence are carried out on these samples. Microscope and scanning electron microscope are applied to investigate the damage morphologies in both 1-on-1 and N-on~l tests. It is found that the laser damage threshold is higher in N-on-1 tests and nodular defect is the main inducement that leads to the damage because nodular ejection with plasma scalding is the typical damage morphology. Similar damage morphology observed in the two tests indicates that the higher laser damage threshold in N-on-1 test is attributed to the mechanical stabilization process of nodular defects, owing to the gradually increased laser fluence radiation. Based on the typical morphology study, some process optimizations are given.     

Theoretical analysis of amplification performance of space-based lasers with different pump configurations

<正>We investigate a theoretical model to accurately predict the output performances of slab laser amplifiers, which is one of the key issues in the study of space-based lasers.The realistic absorbed pump energy density,which induces nonuniformity of stored energy density in the laser medium,is introduced into the model.Using this model,the amplification performances of two space-based laser amplifiers with different pump configurations are compared.The results indicate that the bounce-pumped amplifier(BPA) achieves much higher output energy and efficiency compared with the side-pumped amplifier(SPA);it is also more suitable for space-based lasers.     

自由基聚合物——一类新颖的高性能二次电池材料

自由基聚合物是一种新近发展迅速的电荷储存与传输材料,在电化学超级电容器、光电转换器件、二次电池等方面具有诱人的应用前景.本文着重介绍这类新颖电极材料的结构特征、电化学反应机制,以及国内外的研究发展现状;分析了采用自由基聚合物构建新型二次电池的技术途径和发展趋势.