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991.
992.
Yikun Bu Quan Zheng Qinghua Xue Yingxin Cheng Longsheng Qian 《Optics & Laser Technology》2006,38(8):565-568
A design of LD-pumped Nd:YVO4 laser that generates simultaneous laser action at wavelengths 1064 and 1342 nm by optimizing film design is presented. An optimized continuous-wave (cw) yellow laser at 593.5 nm in room temperature is obtained for the first time. Using type-I critical phase-matching (CPM)LBO crystal, a yellow laser at 593.5 nm is obtained by 1064 and 1342 nm intracavity sum-frequency mixing. The maximum laser output power of 85 mW is obtained when an incident pump laser of 1.8 W is used. The optical-to-optical conversion is up to 4.7%, and the power stability in 24 h is better than ±2.8%. 相似文献
993.
In this paper, relaxation behavior of transmitted light through thin ferrofluid film under an applied magnetic field is measured.
The results show that the intensity of transmitted light through a ferrofluid film increases quickly as soon as an external
magnetic field is applied then weakens with time. If uniformity of the field is poor, the transmission of light continuously
decreases in a measured duration. Otherwise, the transmission of light will tend increasingly towards a stable value after
it decreases to a minimum value while the gradient of the field is low. The relaxation time would increase to an order of
some hundreds seconds magnitude and is dependent on the strength of magnetic field and viscosity of the ferrofluids. The field-induced
relaxation behaviors of transmitted light through ferrofluids correspond to anisotropic microstructure of the ferrofluids
under applied magnetic field.
PACS 75.50.Mm; 78.20.Ls 相似文献
994.
L.A. Farina X. Bai . Kurdak S. Chakrabarti P. Bhattacharya M.Shayegan 《Physica E: Low-dimensional Systems and Nanostructures》2006,34(1-2):187
We have fabricated devices on GaAs/AlGaAs heterostructures, containing two-dimensional electron gases, that consist of three point contacts surrounding an etched antidot with an Al/AlOx/Al single electron transistor. The single electron transistor measurement shows rearrangement of neighboring charged impurities with a characteristic stability time scale of 20 s in one device and greater than 1 h in a second device. We also measured the resistance of the point contact–antidot constriction versus magnetic field. In a device with a 20 s stability time, we see a high noise level and poor reproducibility. In a device with a long stability time, much greater than 1 h, we are able to see reproducible features including Aharonov–Bohm oscillations. 相似文献
995.
Cheng Quan Wang Hui Wang Yan Ming Liu* College of Chemistry Chemical Engineering Xinyang Normal University Xinyang China 《中国化学快报》2007,18(4):452-454
A rapid and sensitive method for the analysis of three catecholamines by capillary electrophoresis(CE)with directchemiluminescence(CL)detection is described.The detection limits(S/N=3)were 1.3*10-8g/mL for isoprenaline,1.0*10-8g/mL for epinephrine and 2.8*10-8g/mL for dopamine.The proposed method was successfully applied to theanalysis of catecholamines in urine samples of cigarette smokers and nonsmokers.The results showed that there is a close relationbetween the release of dopamine in human body fluids and cigarette smoking/nonsmoking. 相似文献
996.
Yu Dong SHEN Hai Qiang WU Lin Kun AN Zhi Shu HUANG Xian Zhang BU Lian Quan GU 《中国化学快报》2005,16(12):1581-1583
A new bisbenzofuran analogue Ⅶ was achieved unexpectedly in one step procedure from 1-(4-methoxyphenoxy)acetone Ⅰ by using Amberlyst 15 resin as catalyst in excellent yield. The structure was elucidated by spectroscopy analysis including ^1H-NMR, ^13C-NMR, DEPT, ESI-MS, element analysis. 相似文献
997.
Using orthogonal protection-deprotection glycosylation strategy, a series of diosgenyl glycosides with same of monosaccharides component but different in sequence were synthesized. The antitumor activity in vitro of synthesized diosgenyl glycosides was evaluated by standard MTT assay. It was observed that diosgenyl glycosides with a rhamnopyranosyl at C2′ of glucopyranosyl residue show potent antitumor activity in vitro. 相似文献
998.
Bao Quart YUAN 《数学学报(英文版)》2007,23(3):439-448
In this paper we consider the Cauchy problems of Burgers' equations and the Deybe system. Their existence and uniqueness of the time-global solutions for small initial data in some pseudomeasure spaces are obtained. The asymptotic stability of small solutions is proved. As an immediate result the existence and uniqueness of the self-similar solutions are also obtained provided the initial data satisfy the self-similar structures. 相似文献
999.
Bayes分析中多源验前信息融合的ML-II方法 总被引:2,自引:0,他引:2
在Bayes小子样理论中,验前分布的获取和表示是一个关键问题.针对工程实践中遇到的验前信息的多源性,给出了一种基于第二类极大似然估计原理(M L-II)的多源异总体验前分布的融合方法,并通过仿真实例证明了该方法的有效性. 相似文献
1000.
Liping Li Quan Wein Chuanbin Jiang Xiaolin Ren Zhigou Yao Wenhui Su 《Hyperfine Interactions》1995,96(1):237-243
The samples of Eu1–x
Sr
x
FeO3–y
(x=0.0–1.0) were prepared by the solid state reaction method. Their X-ray diffraction patterns and57Fe Mössbauer spectra at room temperature were measured. It is found that Sr ions incorporate in the lattice of EuFeO3, the change of crystal structure is related to the dopant.57Fe Mössbauer spectra consist of one magnetic, one doublet and one single paramagnetic components. The Fe ions in the cubic phase are in intermediate valence state between Fe(III) and Fe(IV) and may participate in electron hopping. 相似文献