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31.
针对传统大功率Si,GaAs固态微波源效率低和高温度性能差的不足,采用导热系数优良的宽禁带GaN单元功放模块集成、低损耗同轴波导径向空间功率合成方法,研制出一种1.2 kW全固态C波段高效率宽禁带GaN微波源。实验结果表明:该方法实现了大功率固态微波源高效率及连续长时间高温风冷散热运行,系统安全可靠。单路功放模块集成6位移相器,移相精度5.6,增益35 dB,输出功率大于31 W。系统连续波输出功率1.2 kW ,总效率30%,谐波抑制-54.8 dBc;杂散-63.69 dBc,相位噪声-94.03 dBc/Hz@1kHz。 相似文献
32.
Using a series of quantum correlated photon pairs, we propose a theoretical scheme for any-to-any multi-user quantum key distribution network based on differential phase shift. The differential phase shift and the different detection time slots ensure the security of our scheme against eavesdropping. We discuss the security under the intercept-resend attack and the source replacement attack. 相似文献
33.
N. Chai W.D. Kulatilaka S.V. Naik N.M. Laurendeau R.P. Lucht J.P. Kuehner S. Roy V.R. Katta J.R. Gord 《Applied physics. B, Lasers and optics》2007,88(1):141-150
We report the application of electronic-resonance-enhanced coherent anti-Stokes Raman scattering (ERE-CARS) for measurements
of nitric oxide concentration ([NO]) in three different atmospheric pressure flames. Visible pump (532 nm) and Stokes (591 nm)
beams are used to probe the Q-branch of the Raman transition. A significant resonance enhancement is obtained by tuning an
ultraviolet probe beam (236 nm) into resonance with specific rotational transitions in the (v’=0, v”=1) vibrational band of
the A2Σ+–X2Π electronic system of NO. ERE-CARS spectra are recorded at various heights within a hydrogen-air flame producing relatively
low concentrations of NO over a Hencken burner. Good agreement is obtained between NO ERE-CARS measurements and the results
of flame computations using UNICORN, a two-dimensional flame code. Excellent agreement between measured and calculated NO
spectra is also obtained when using a modified version of the Sandia CARSFT code for heavily sooting acetylene-air flames
(φ=0.8 to φ=1.6) on the same Hencken burner. Finally, NO concentration profiles are measured using ERE-CARS in a laminar,
counter-flow, non-premixed hydrogen-air flame. Spectral scans are recorded by probing the Q1 (9.5), Q1 (13.5) and Q1 (17.5) Raman transitions. The measured shape of the [NO] profile is in good agreement with that predicted using the OPPDIF
code, even without correcting for collisional effects. These comparisons between [NO] measurements and predictions establish
the utility of ERE-CARS for detection of NO in flames with large temperature and concentration gradients as well as in sooting
environments.
PACS 07.88.+y; 42.62.Fi; 42.65.Dr 相似文献
34.
本文研究了用新生MnO2作吸剂,对水中直接耐晒蓝(B2RL)染料进行脱色的特性,探讨了影响吸附的因素,并给出适宜的吸附条件,在本试验条件下可使B2RL脱色主达95%。 相似文献
35.
36.
To identify and eliminate the inner filter effects (IFEs), prepositive and side cells containing absorbents are fixed beside
the fluorescer contained cell. In this way, excitation and emission lights can be quenched by primary and secondary outer
filter effects respectively, depending on absorbent concentration and cell length. Herein the quenching of emission fluorescence
caused by IFEs can be equally reduced by outer filter effects (OFEs) and the interference of IFEs was eliminated. This approach
was experimentally used for identifying the interaction mode and mechanism between BSA and nanoAg. Results showed that the
quenching of BSA fluorescence and synchronous fluorescence mainly attributes to IFEs, instead of static/dynamic fluorescent
quenching. In view of the above, the elimination of the interference of IFEs by the design of OFEs plays an important part
in the precise application of fluorescence detector. 相似文献
37.
ZHAO Chuan SUN Sheng-Sen LI Cheng ZHANG Xiao-Jie HE Kang-Lin AN Qi CHEN Hong-Fang DAI Hong-Liang FENG Chang-Qing HENG Yue-Kun HUANG Ya-Qi HUANG Yan-Ping GUO Jian-Hua LI Wei-Dong LI Xiu-Rong LIU Fang LIU Huai-Min LIU Shu-Bin LIU Shu-Dong LIU Yong MA Xiang MAO Ze-Pu SHAO Ming SUN Yong-Jie SUN Zhi-Jia WU Jin-Jie YANG Gui-An ZHAO Lei ZHU Xing-Wang ZUO Jia-Xu 《中国物理C(英文版)》2011,35(1):72-78
The time calibration for end cap TOF system of BESⅢ is studied in this paper.It has achieved about 110 ps time resolution for muons in dimu events.The pulse height correction using electronic scan curve and the predicted time calculated using Kalman filter method are introduced.This paper also describes the study of using electrons and muous as calibration samples. 相似文献
38.
Adare A Adler SS Afanasiev S Aidala C Ajitanand NN Akiba Y Al-Bataineh H Alexander J Al-Jamel A Aoki K Aphecetche L Armendariz R Aronson SH Asai J Atomssa ET Averbeck R Awes TC Azmoun B Babintsev V Baksay G Baksay L Baldisseri A Barish KN Barnes PD Bassalleck B Bathe S Batsouli S Baublis V Bauer F Bazilevsky A Belikov S Bennett R Berdnikov Y Bickley AA Bjorndal MT Boissevain JG Borel H Boyle K Brooks ML Brown DS Bruner N Bucher D Buesching H Bumazhnov V Bunce G Burward-Hoy JM Butsyk S Camard X 《Physical review letters》2007,98(23):232302
We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from dijets in Cu+Cu and Au+Au collisions at square root sNN=62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from Delta phi=pi in central and semicentral collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models. 相似文献
39.
考察研究了丹参主要有效成分隐丹参酮和丹参酮 A在不同酸性介质中的荧光特性。结果表明隐丹参酮和丹参酮 A均有很宽的 p H发光范围 ( p H=1- 11)。在 p H=2 - 3时 ,隐丹参酮和丹参酮 A荧光发射最强。在强酸 ( 5mol/L HCl)和强碱 ( 2 mol/L Na OH)介质中隐丹参酮和丹参酮 A的荧光均被显著猝灭 ,同时荧光光谱发生明显蓝移。表明隐丹参酮和丹参酮 A在强酸强碱下分子结构发生了明显变化。从而为它们的药理及其理化性质等的研究提供了分子结构信息等的依据 相似文献
40.
Based on Biot's dynamic poroelastic theory, a foundation–soil interaction model is established to investigate the vertical vibrations of a rigid circular foundation on poroelastic soil excited by incident plane waves, including the fast P waves and SV waves. Scattering waves caused by the foundation and fluid–solid coupling due to the pore water in the soil are also considered in the model. The solution of the vertical vibrations of the foundation subjected to seismic waves are obtained by solving two sets of dual integral equations derived from the mixed boundary-value conditions. The different vertical vibrations of foundation rest on elastic and saturated half-space are compared. The influences of incident angle, permeability of soil and foundation mass on the vertical vibrations of the foundation are then discussed. The results show that resonant phenomenon of the foundation is observed at certain excitation frequencies; the effects of the pore water on the foundation vertical vibrations are significant. In addition, significant differences are found when the foundation is excited by P waves and SV waves, respectively. 相似文献