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61.
酞菁钴薄膜的折射率及吸收特性 总被引:3,自引:1,他引:2
通过真空镀法在单晶硅片上制备了酞菁钴薄膜,在波长扫描和入射角可变全自动椭圆偏振光谱仪上研究了CoPc薄膜的椭偏光谱并分析了其电子结构。 相似文献
62.
通过开展应用数学教学活动和开办《应用数学学校》的多年实践 ,我校学生结合实际学习和应用数学知识的意识和能力不断提高 ,在上海市数学知识应用竞赛和美国大学生数学建模竞赛中连续取得好成绩 ,为了争取把这项工作做得更好 ,我们作了进一步思考和打算 相似文献
63.
闪光灯泵浦的Nd:KGd(WO4)2激光器 总被引:1,自引:0,他引:1
报道了用闪光灯泵浦的掺钕的钨酸钆镓(Nd3+:KGd(WO4)2激光器.在重复频率1Hz,脉宽120μs的灯泵下,测量了不同透过率下激光输出能量,获得最大输出能量384mJ,斜率效率1.0%,外推阈值0.54J.在调Q运行时,Nd:KGW晶体的斜率效率为0.16%,最大输出能量46mJ. 相似文献
64.
Da-Zhi Li Li Gan Zi-Qiang Yang Zheng Liang Jia-Yin Li 《International Journal of Infrared and Millimeter Waves》1997,18(10):1885-1896
The dispersion characteristic of the plasma-loaded relativistic backward wave oscillator has been analyzed. The theoretical
model has been established and the numerical calculations accord with the experimental results, which provides some useful
suggestions on the designing of slow-wave structure of BWO. 相似文献
65.
金淦 《Annals of Differential Equations》1998,(4)
1IntroductionStabilityintermsoftwomeasures,thisconceptenableustounifyava-rietyofstabilityconceptsandtoofferageneralandunifiedframeworkforinvestigationofstabilitytheory.AndtheoriginalLiapunovtheoremshavebeenextended,generalizedandweakenedinvariousaspects[3… 相似文献
66.
Using the notion of biconnected sum we define the biconnected sum (T1, M1)§(T2,M2) of two involutions (T1M1) and (T2,M2) which is an involution on the biconnected sum M1,§M2. A connected involution is said to be reducible if it can be expressed as a biconnected sum of two connected involutions.Theorem Each connected involution (T, M) can be decomposed into a bi-connected sum of connected irreducible involutions (T, M)=(T1, M1)§…§(Tq,Mq),and (?) where the coefficients of Hn_1(M) are in Z/2 Z if M is unoriented, in Z if is oriented . 相似文献
67.
68.
Kelly A. Burke Sona Sivakova Blayne M. McKenzie Patrick T. Mather Stuart J. Rowan 《Journal of polymer science. Part A, Polymer chemistry》2006,44(17):5049-5059
We report herein studies on the liquid crystalline behavior of a series of supramolecular materials that contain different ratios of two complementary symmetrically-substituted alkoxy-bis(phenylethynyl)benzene AA- and BB-type monomers. One monomer has thymine units placed at either end of the rigid mesogenic core, while the other has N6-(4-methoxybenzoyl)-adenine units placed on the ends. Differential scanning calorimetric and polarized optical microscopy studies have been carried out on these systems. These studies show that the material's behavior is strongly dependent on its thermal history. As a result, the materials can exhibit, on heating, either a liquid crystalline phase, a crystalline phase, or the coexistence of crystalline and liquid crystalline regions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5049–5059, 2006 相似文献
69.
We are interested in improving the Varshamov bound for finite values of length n and minimum distance d. We employ a counting lemma to this end which we find particularly useful in relation to Varshamov graphs. Since a Varshamov
graph consists of components corresponding to low weight vectors in the cosets of a code it is a useful tool when trying to
improve the estimates involved in the Varshamov bound. We consider how the graph can be iteratively constructed and using
our observations are able to achieve a reduction in the over-counting which occurs. This tightens the lower bound for any
choice of parameters n, k, d or q and is not dependent on information such as the weight distribution of a code.
This work is taken from the author’s thesis [10] 相似文献
70.
The non-resonant third-order non-linear optical properties of amorphous Ge20As25Se55 films were studied experimentally by the method of the femtosecond optical heterodyne detection of optical Kerr effect. The real and imaginary parts of complex third-order optical non-linearity could be effectively separated and their values and signs could be also determined, which were 6.6 × 10−12 and −2.4 × 10−12 esu, respectively. Amorphous Ge20As25Se55 films showed a very fast response in the range of 200 fs under ultrafast excitation. The ultrafast response and large third-order non-linearity are attributed to the ultrafast distortion of the electron orbitals surrounding the average positions of the nucleus of Ge, As and Se atoms. The high third-order susceptibility and a fast response time of amorphous Ge20As25Se55 films makes it a promising material for application in advanced techniques especially in optical switching. 相似文献