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991.
992.
993.
Simulation of dielectric resonator for a high-T_c radio frequency superconducting quantum interference device 下载免费PDF全文
Nowadays,the high-critical-temperature radio frequency superconducting quantum interference device (high-T c rf SQUID) is usually coupled to a dielectric resonator that is a standard 10 × 10 × 1 mm 3 SrTiO 3 (STO) substrate with a YBa 2 Cu 3 O 7-δ (YBCO) thin-film flux focuser deposited on it.Recently,we have simulated a dielectric resonator for the high-T c rf SQUID by using the ANSOFT High Frequency Structure Simulator (ANSOFT HFSS).We simulate the resonant frequency and the quality factor of our dielectric resonator when it is unloaded or matches a 50-impedance.The simulation results are quite close to the practical measurements.Our study shows that ANSOFT HFSS is quite suitable for simulating the dielectric resonator used for the high-T c rf SQUID.Therefore,we think the ANSOFT HFSS can be very helpful for investigating the characteristics of dielectric resonators for high-T c rf SQUIDs. 相似文献
994.
Making use of the spectral narrowing of ultra-short pulses subject to amplification in the gain bandwidth media, a multi-ultra-short pulse coherent synthesizer (MUSPCS) developed from the traditional regenerative amplifier is proposed, and its operational principle is described. In the small signal gain regime, the theoretical analysis and numerical simulation on the MUSPCS have been made. The simulation results show that the narrow bandwidth flat-top long pulse can be composed if the parameters were controlled carefully. 相似文献
995.
Background
Minichromosome maintenance proteins (Mcm) 2, 3, 4, 5, 6 and 7 are related by sequence and form a variety of complexes that unwind DNA, including Mcm4/6/7. A Mcm4/6/7 trimer forms one half of the Mcm2-7 hexameric ring and can be thought of as the catalytic core of Mcm2-7, the replicative helicase in eukaryotic cells. Oligomeric analysis of Mcm4/6/7 suggests that it forms a hexamer containing two Mcm4/6/7 trimers, however, under certain conditions trimeric Mcm4/6/7 has also been observed. The functional significance of the different Mcm4/6/7 oligomeric states has not been assessed. The results of such an assessment would have implications for studies of both Mcm4/6/7 and Mcm2-7. 相似文献996.
997.
In order to analyze the power conversion efficiency (PCE) and the gain characteristics of the phosphate glass Er3+–Yb3+-co-doped waveguide amplifier (EYCDWA), formulas are derived from the rate equations and the light propagation equations under the uniform dopant and the steady-state conditions. In the derivation of these formulas, we have neglected the amplified spontaneous emission (ASE) and have introduced the initial energy transfer efficiency. By using these formulas, the effects of the pump power, signal power and waveguide length on the PCE and the gain characteristics of the EYCDWA are analyzed, and some useful results are obtained in three kinds of pumped styles, i.e. the forward-, backward- and bidirectional pumped styles. 相似文献
998.
Yang Wu Qing Ma Xiangrong Song Yu Zheng Wen Ren Jinkun Zhang Liang Ouyang Fengbo Wu Gu He 《Journal of polymer science. Part A, Polymer chemistry》2012,50(21):4532-4537
A novel amphiphilic poly(ethylene glycol)‐block‐poly(γ‐cholesterol‐L ‐glutamate) (mPEG–PCHLG) diblock copolymer has been synthesized. The mPEG–PCHLG copolymer has good biocompatibility and low toxicity. The mPEG–PCHLG copolymers could aggregate into nanoparticles with PCHLG blocks as the hydrophobic core and PEG blocks as the hydrophilic shell through emulsion solvent evaporation method. The copolymers were characterized by nuclear magnetic resonance spectroscopy, mass spectrum, Fourier transform infrared spectroscopy, and gel permeation chromatography. The particle sizes, size distributions, and zeta potentials of nanoparticles can also be determined by dynamic light scattering and transmission electron microscopy. This work provides a new and facile approach to prepare amphiphilic block copolymer nanoparticles with controllable performances. This novel copolymer may have potential applications in drug delivery and bioimaging applications.© 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
999.
1000.
Dr. Binjie Guo Dr. Xin Huang Prof. Dr. Chunling Fu Prof. Dr. Shengming Ma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(51):18343-18348
A mild and efficient method using readily available 1‐aryl‐2,3‐allenols and unprotected‐N indoles, Au+‐catalyzed cyclization, and aromatization to afford the final [4C+2C] products, carbazoles 4, with an excellent selectivity, is reported. The reaction demonstrates excellent regioselectivity and allows the N?H unit to undergo reactivity unprotected. A mechanism involving a spiropolycyclic intermediate has been proposed and synthetic application is also demonstrated. 相似文献