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951.
952.
本文详细介绍了自行研制成的电子回旋共振微波等离子体装置的结构,性能和技术指标。并应用高斯计,法拉第筒和朗缪探针对装置的磁场位形发布和等离子的电流及密度进行了测量。 相似文献
953.
A.A. Bykov A.K. Bakarov A.K. Kalagin A.V. Goran A.I. Toropov S.A. Vitkalov 《Physica E: Low-dimensional Systems and Nanostructures》2006,34(1-2):97
The effect of microwave radiation in the frequency range from 1.2 to 10 GHz on the magnetoresistance of a high-mobility two-dimensional electron gas has been studied in a GaAs quantum well with AlAs/GaAs superlattice barriers. It has been found that the microwave field induces magnetoresistance oscillations periodic in the reciprocal magnetic field (1/B). It has been shown that the period of these oscillations in the covered frequency range depends on the microwave radiation power. 相似文献
954.
The (Ni0.20Zn0.60Cu0.20)Fe1.98O4 ferrite was sintered using microwave sintering and conventional sintering technique, respectively. It was found that microwave sintering technique can effectively promote the forward diffusion of ions and thus accelerate the sintering process, resulting in the grain growth and the densification of matrix. At the low frequency of 100 kHz, the magnetizing contribution of domain wall motion is predominant, and compact and coarse matrixes are favorable for domain wall motion, giving rise to improvement of relative initial permeability and loss of ferrites. Using microwave sintering technique, for the (Ni0.20Zn0.60Cu0.20)Fe1.98O4 ferrite, the relative initial permeability μi of about 2000 and the relative loss factor tanδ/μi of about 8.7×10−6 at 100 kHz were achieved at only 980 °C sintering temperature. In addition, the sintering time of ferrites was reduced from 5 to 0.5 h by using microwave sintering technique. 相似文献
955.
Shen Maoxing Zheng Wutuan 《大学数学》1998,(4)
在微波通讯中,电波射束和障碍物之间应留有足够的余隙,以保证能量的有效传输.本文考虑地球表面自然凸特征,建立在此意义下的余隙的数学模型,从而获得微波传输路由的数学模型.利用此模型的解与海拔制高点的余隙进行比较,便可获得工程建设中的最佳余隙值及相联系的有效的经济的路由设计. 相似文献
956.
S. Kassi 《Journal of Molecular Spectroscopy》2004,228(2):293-297
We report new microwave measurements for the (15NH2)2CO and (14NH2) (15NH2)CO isotopologues of urea. The spectra were recorded between 5 and 20 GHz with our MWFT spectrometer coupled to a newly built heated nozzle. A new centrifugal distortion analysis was performed for the (15NH2)2CO species including all available data. For the (14NH2) (15NH2)CO species the hyperfine structure was recorded for the first time. 相似文献
957.
The microwave spectrum of methyl formate (HCOOCH3) has been observed in the frequency range from 7 to 200 GHz. New 348 lines were assigned to E-species in the first excited torsional state. By combining these lines with previously reported data, a global analysis of A- and E-species lines of the ground and first excited torsional states were carried out on the basis of the internal axis method. A total of 3862 transitions were fitted to a Hamiltonian model involving 69 molecular parameters to a weighted unitless standard deviation of 1.96. 相似文献
958.
Alan M. Jones 《Tetrahedron》2009,65(2):563-5718
A practical strategy for the synthesis of diazabenz[e]aceanthrylene-based heterocycles is reported. The key step in this approach is a microwave-assisted condensation and cyclisation reaction between an anthranilic acid derivative and a 2′-carbomethoxy substituted N-aryl lactam. The scope of the reaction has been explored as a function of both the nature and position of substituents in both components and variations in lactam ring size. Interesting structural and spectroscopic variations observed across the compound collection are described and explored using NMR, X-ray crystallography and computational techniques. 相似文献
959.
The efficient synthesis of N-(diphenylmethylene) glycine alkyl esters was achieved for the first microwave irradiation under solvent-free condition,using PEG or quaternary ammonium salts as phase transfer catalysts(PTCs).Under the optimum conditions, N-(diphenylmethylene) glycine alkyl esters were obtained in excellent yields in most cases. 相似文献
960.
Microwave absorption properties of double-layer absorbers made of NiCoZn ferrites and hollow glass microspheres electroless plated with FeCoNiB 总被引:1,自引:0,他引:1
Amorphous FeCoNiB coatings were deposited by an electroless plating technique on the hollow glass microspheres. NiCoZn spinel ferrites sintered show two dispersion peaks (1.81 and 6.98 GHz). By fitting its permeability dispersion spectra, the one at low frequency is believed to be due to the domain wall movement mechanism, the other one is due to the spin rotation mechanism. Used in a single-layer absorber structure, neither the hollow glass microspheres coated nor the NiCoZn could meet the demand of light weight. However, if a double-layer absorber structure is used, not only the total weight of an absorber is reduced, but also the microwave absorption performance is enhanced. 相似文献