高频引力波的应用前景、产生机制和探测方案

较为全面地论述了高频引力波的应用前景、产生机制和探测方案 .     

Nonrelativistic phase in γ-ray burst afterglows

The discovery of multiband afterglows definitely shows that most γ-ray bursts are of cosmological origin. γ-ray bursts are found to be one of the most violent explosive phenomena in the Universe, in which astonishing ultra-relativistic motions are involved. In this article, the multiband observational characteristics of γ-ray bursts and their afterglows are briefly reviewed. The standard model of γ-ray bursts, i.e. the fireball model, is described. Emphasis is then put on the importance of the nonrelativistic phase of afterglows. The concept of deep Newtonian phase is elaborated. A generic dynamical model applicable in both the relativistic and nonrelativistic phases is introduced. Based on these elaborations, the overall afterglow behaviors, from the very early stages to the very late stages, can be conveniently calculated.     

Enhancement of tribological properties in siliconized graphite via hierarchically hybrid SiC/C composite

This study aims to investigate tribological properties in a siliconized graphite(СГ-П-0.5) and hierarchically hybrid Si C/C composites at the load ranging from 10-40 N under dry air/water lubrication conditions. A feasible liquid silicon infiltration(LSI) was used to fabricate the Si C/C composites. Morphology and phase identification of two materials were characterized and analyzed by scanning electron microscope(SEM) and energy dispersive spectrometer(EDS). An image feature extraction was used to post-process the data of wear test, further to gain the wear properties of the samples. The results demonstrated that a lower coefficient of friction(COF) and wear rate can be achieved in the LSI Si C composites than that in the sample of СГ-П-0.5. Both COF decreased under waterlubricated conditions, compared with that under the dry air lubrication. The excellent tribological properties in two materials can be due mainly to the microstructure of the СГ-П-0.5 sample, showing much more graphite and Si dispersed on the matrix. The СГ-П-0.5 sample indicated the typical oxidative wear mechanism, whereas, the sample of LSI Si C demonstrated the combined oxidative and fatigue wear. This finding can provide a promising new siliconized graphite materials for ceramic rolling bearings.     

一个双变量元胞自动机模型的定性研究

实际激发系统通常可由一对偏微分方程来反映,具有两个变量。根据奇异摄动理论的结论,激发介质中非线性波在传播过程中应满足色散关系和曲率效应。本文介绍了一个具有双变量的激发介质元胞自动机模型,利用该模型进行了数值模拟,模拟结果定性体现了色散关系和曲率效应。文中还模拟再现了靶波自维持现象,并对此现象的产生机制进行了分析。     

调酸式催化水解稻壳制备乙酰丙酸的研究

试验采用调酸式稀酸催化水解工艺,从稻壳中提取乙酰丙酸.根据Box-Behnken实验设计方法,确定影响乙酰丙酸收率的主要因素分别为硫酸浓度、反应温度、反应时间和液固比,分别在三水平条件下进行了27次试验,并建立了二次方程的模型,R2=0.986 1,显示该模型具有较好的拟合度;进一步通过响应面分析确定优化的水解条件:硫酸浓度3.9%,温度227℃,反应时间32 min,液固比16:1.在调酸催化水解工艺条件下,目标产物收率为38.426%,与模型估计值接近.     

基于遗传算法的地空导弹装备备件优化模型

对影响战备可靠度的各种因素进行分析，指出备件优化是提高地空导弹武器装备战备可靠度的唯一有效途径；根据地空导弹武器系统的组成和工作特点，建立了战备可靠度和备件优化模型；依据遗传算法的特点，提出了将遗传算法用于求解备件优化问题的方法，并给出了求解过程，从而有效地解决了备件优化这一复杂而困难的问题，保证地空导弹武器系统具有高的战备可靠度。     

非线性弹性杆中的NLS型孤波

从理论上给出了在非线性弹性杆中存在的ＮＬＳ型孤波以及此孤波所满足的非线性Ｓｃｈｒｄｉｎｇｅｒ方程． 当非线性常数ｎ＝ ２ 时， 存在ＫｄＶ孤立子； 而对于ｎ＝ ３ 的非线性弹性杆， 不存在ＫｄＶ 孤立子，但确存在ＮＬＳ孤立子     

电磁源近场测量理论与技术研究进展

讨论了近场的两类基本电磁环境———束缚场与消失态;前者包含静态场(按r-3规律衰减)和感应场(按r-2规律衰减);后者包含消失平面波谱,当离源的距离增大时指数地急速下降。束缚场在本文中称为类消失场。近年来两者都发现了电磁波在自由空间以超光速传播的现象,实验上还进一步观察到负波速。由最近几年的实验,对束缚场而言结果并不支持普遍认为的以光速( v = c)迟滞传播的观点;根据对天线近区内无迟滞现象的观测,提供了束缚电磁场的非局域性的实验证据,有的实验甚至达到了高度超光速,即v≥10c。非局域性是一个量子力学概念,故束缚场的非局域特性可能在经典电磁学与量子力学之间建立紧密联系。在实际应用方面,论述了从辐射近场测量数据转换到辐射远场的技术,包括平面波谱( PWS)法和微波二端口网络散射矩阵法。此外还叙述了与近场微波显微镜发展的有关问题。但本文强调在近场测量中发现的新现象,给出了理论上的多个对偶关系。讨论了近场超光速现象的量子解释,认为应从理论上应用“消失态是虚光子”的思想。本文提出应当重视的一个研究领域是：在不使用反常色散和LHM超材料的近场条件下获得的在自由空间的内向波。最后指出了使用环天线做进一步实验的必要性。     

江苏沿海滩涂围垦对近岸风浪场的影响

利用江苏沿海近期水深数据以及西连岛风测站1981—1998年风况资料,采用P-III曲线计算重现期风速并推求外海深水波要素,对江苏海域50年一遇设计风浪场进行了模拟计算。在模型验证的基础上,模拟计算了江苏沿海滩涂围垦规划(2010—2020年)后江苏近岸风浪场,探讨了江苏近岸50年一遇风浪场的分布特征,同时对比分析江苏近岸8个采样点工程前后50年一遇设计波要素的变化。结果表明:江苏围垦规划实施后,江苏近岸50年一遇设计波要素有减小趋势;北部近岸海域的有效波高和平均波周期基本不变,而南部近岸海域变化较大。其中,南部海域采样点有效波高最大降幅0.62 m,位于洋口港-吕四港近岸区域,采样点平均波周期最大降幅1 s,位于东沙围垦区东部;水深地貌形态和风区长度是影响江苏近岸重现期波浪的重要因素。     

具有褶皱表面的磁性多层膜中线性及非线性表面静磁波

In these formulae,γ is the gyromagnetic ratio,and f1and f2 are used as the magnetic andnonmagnetic fractions in the multilayers,respectively.Therefore f1=d1/ ( d1+d2 ) and f2 =d2 / ( d1+d2 ) ,with d1representing the thickness of magnetic layers and d2 the thickness of nonmagneticlayers.In our previous paper[2 3 ] ,we obtained the useful non-zero components of the third-ordermagnetizations with foundation al frequencyω,for a surface magnetostatic wave propagatingalong the x axis,which arwhere…