首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   29篇
  免费   0篇
  国内免费   3篇
化学   13篇
力学   2篇
数学   6篇
物理学   11篇
  2021年   2篇
  2019年   1篇
  2018年   1篇
  2017年   2篇
  2015年   3篇
  2014年   3篇
  2012年   1篇
  2011年   1篇
  2006年   1篇
  2005年   1篇
  2003年   1篇
  2002年   4篇
  2001年   3篇
  2000年   2篇
  1999年   2篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1982年   1篇
排序方式: 共有32条查询结果,搜索用时 203 毫秒
21.
一种非火药驱动气体炮内弹道模型及发射诸元协调   总被引:1,自引:0,他引:1  
介绍一种新型非火药驱动的气体炮,它有五个气室控制气体炮的整个发射过程。给出了该气体炮的结构原理和内弹道数学模型,并通过计算机模拟,分析了这种气体炮的发射参数的协调和优化关系,指出了影响弹丸最大加速度的主要因素。  相似文献   
22.
In this note we improve two conditions given by Lepingle and Memin^[3,4] for the uniform integrability of exponential martingales,and given some conditions for their L^r-integrability.  相似文献   
23.
1 Introduction  Inrecentyears ,increasingattentionhasbeen paidtohigh peak powerall solid statepulsedblue greenlasersforsomeapplicationssuchasspectroscopy ,display ,opticaldatastorage ,underseacommunicationsandsoon .Suchlaserscanberealizedbyintracavityorexter…  相似文献   
24.
新型高能氧化剂在固体推进剂中占据较大比重,是提高固体推进剂能量水平的关键材料之一。本文以ADN、HNF、TNAZ及HNFX为例,着重对其合成路线、物理化学、爆轰性能及改性等方面的最新研究进展进行综述,并展望了其在固体推进剂中的发展方向与应用前景。  相似文献   
25.
Beam quality factor (M2) and far-field scattering angle of LD end-pump Nd : YVO4 laser were measured by slit-scanning method. The experimental results showed that the laser operated on a multi-mode state. The corresponding analytical treatments for slit-scanning method and M2 factor measurement also were presented in this paper.  相似文献   
26.
Nd3+ : Ca4GdO(BO3)3, known as Nd : GdCOB, is a new self-frequency doubling laser crystal. Using Cr4+ : YAG as passive Q-switch, we have realized the Q-switched laser running at 0.53 μm with an Nd : GdCOB crystal. Meanwhile, the pulse width, the single pulse energy and the repetition rate under different small-signal transmission of Cr4+ : YAG and different pump conditions are measured and the numerical solutions of the coupling wave rate equations agree with the experimental results.  相似文献   
27.
Poly(3-difluoroaminomethyl-3-methyl oxetane (DFAMO)/3-azidomethyl-3-methyl oxetane (AMMO)) (PDA) can be used as an energetic pre-polymer in the binder systems of solid propellants and polymer-bonded explosives (PBXs). The cationic solution polymerization affords PDA using butane diol (BDO) and boron trifluride etherate (TFBE) as initiator and catalyst, separately. Its molecular structure is characterized and thermal decomposition behavior is investigated by thermogravimetric analysis (TG), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The copolymer has good thermal stability and exhibits a three-step mass-loss process with the first two steps mainly belonging to the thermal decomposition of difluoroamino and azido groups, respectively. DSC method is performed to evaluate the compatibility of PDA with some energetic components and inert materials. More than half of the selected materials are compatible with PDA, which including cyclotrimethylenetrinitramine (RDX), 2,4,6-trinitrotoluene (TNT), 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), pentaerythritol tetranitrate (PETN), ammonium perchlorate (AP), ammonium nitrate (AN), potassium nitrate (KNO3), aluminum powder (Al), aluminum oxide (Al2O3), 2-nitrodiphenylamine (NDPA) and 1,3-diethyl-1,3-diphenyl urea (C1).  相似文献   
28.
Let D be a bounded C~3-domain in R~d and(a_(ij))be a bounded symmetric matrixdefined on D.Consider the symmetric form(u,v)=1/2∫_D a_(ij)(x)(u(x))/(x_i) (v(x))/(x_j)dx,u,v∈H~1(D).Under some assumptions it is shown that the diffusion process associated with the regularDirichlet space(,(H~1(D))on L~2(D)can be characterized as a unique solution of acertain stochastic differential equation.  相似文献   
29.
A novel copolymer with naphthalimide pendant group was prepared, in which a tertiary amine acts as an electron donor and quenches the fluorescence of the 4‐amino‐1,8‐naphthalimide fluorophore via the photo‐induced electron transfer process. When a photoacid generator was added, fluorescence enhancement of the copolymer in the net film was induced, this would be applied to generate patterned fluorescent images. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
30.
The Gaussian kernel operators on white noise functional spaces, including second quantization, Fourier-Mehler transform, scaling, renormalization, etc. are studied by means of symbol calculus, and characterized by the intertwining relations with annihilation and creation operators. The infinitesimal generators of the Gaussian kernel operators are second order white noise operators of which the number operator and the Gross Laplacian are particular examples.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号