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991.
992.
介绍了二类不同结构的(表面和侧面发射型)红外发光二极管.研究和分析了它们在低频大电流脉冲注入下的Pp—Ip特性和直流注入下的光谱特性.结果表明:正常情况下,器件具有线性的Pp—Ip特性,直流注入下的发射光谱具有高斯分布形状,对于Burrus表面发射型器件,在0—3A的峰值脉冲电流注入下,部分器件具有的异常Pp—Ip特性:线性-亚线性-超线性区.在20—100mA的直流电流注入下,部分器件的发射光谱具有多峰状. 相似文献
993.
Rajendra Bhatia Xingzhi Zhan 《Proceedings of the American Mathematical Society》2001,129(8):2277-2281
Let be a compact operator on a Hilbert space such that the operators and are positive. Let be the singular values of and the eigenvalues of , all enumerated in decreasing order. We show that the sequence is majorised by . An important consequence is that, when is less than or equal to , and when this inequality is reversed.
994.
An MHB amphiphile, N-stearoyl-l-glutamic acid (C(18)-Glu), forms disk- and fiber-like nanostructures respectively in hydrophilic and hydrophobic environments due to the inter- and intra-molecular H-bonds. 相似文献
995.
996.
Ji-Suo Wang Jian Feng Tang-Kun Liu Ming-Sheng Zhan 《International Journal of Theoretical Physics》2002,41(12):2427-2437
In this paper, the completeness of the k orthonormalized eigenstates of the operator (a
q
f(N
q
))
k
(k 3) is proved. We introduce a new kind of higher order squeezing and an antibunching. The properties of the Mth-order squeezing and the antibunching effect of the k states are investigated. The result shows that these states may form a complete Hilbert space, and the Mth order [M = (m + 1/2)k;m = 0,1,2,. . .] squeezing effects exist in all of the k states when k is even. There is the antibunching effect in all of the states. 相似文献
997.
Yang Shi-Yao Long La-Sheng Wu Zhen-Yi Zhan Meng-Xiong Huang Rong-Bin Zheng Lan-Sun 《Transition Metal Chemistry》2002,27(5):546-549
The coordination polymer [Cu2L2(H2O)6 · 2(H2O)]
n
(L = -tetrachlorophthalate dianion) has been synthesized and characterized by X-ray crystallography, i.r. spectroscopy, electronic spectroscopy and cyclic voltammetry. The structure of the complex is a one-dimensional zigzag chain. The i.r. spectra reveal that the tetrachlorophthalate groups are bismonodentate ligands, and this is confirmed by the crystal structure determination. Cyclic voltammetry reveals two steps of a quasi-reversible oxidation–reduction processes for the complex. 相似文献
998.
A linear comprehensive adsorption model of hydrogen on super activated carbon under supercritical conditions 总被引:1,自引:0,他引:1
Zhan L Li KX Wang YL Meng QH Lv CX Ling LC 《Journal of colloid and interface science》2002,250(1):63-66
The adsorption isotherms of hydrogen on super activated carbon were measured systematically, covering a temperature range of 93-293 K at 20 K intervals and pressures up to 7 MPa. All the experimental data were linearized by adopting the coordinates ln ln(n) vs 1/(ln P). The results indicate that the adsorption limit (P(lim), n(lim)) exists virtually at high pressure and has a certain physical meaning. Based on the adsorption limit, further analyses were carried out by modeling the adsorption isotherms in the coordinates ln(n(lim)/n) vs ln(RT(ln(P(lim)/P) and a linear comprehensive adsorption model was proposed in the form n (lim)=n.exp(psi T+lambda/T-c/) (beta).[RT ln( P (lim)P )] (b) which can predict the adsorption isotherm of hydrogen on activated carbon in supercritical conditions. 相似文献
999.
LiNi1-xAlxO2(x=0~1.0)固溶体结构的XRD研究 总被引:5,自引:1,他引:4
利用溶胶凝胶法制备了新型锂离子二次电池正极材料LiNi1-xAlxO2(x=0,0.1~1.0)固溶体,X射线衍射结果表明,在0≤x≤1范围内,材料均为具有α-NaFeO2型结构的LiNi1-xAlxO2固溶体单相.随着Al固溶量的增加,晶胞参数发生变化,a轴缩短,c/a比增大,晶胞体积V0减小,材料的层状属性更加明显. 相似文献
1000.
In Csáki et al.
(1) and Révész and Willekens(9) it was proved that the length of the longest excursion among the first n excursions of a plane random walk is nearly equal to the total sum of the lenghts of these excursions. In this paper several results are proved in the same spirit, for plane random walks and for random walks in higher dimensions. 相似文献