共查询到20条相似文献,搜索用时 0 毫秒
1.
C. S. Kou J. Y. Huang C. M. Tsai 《International Journal of Infrared and Millimeter Waves》1999,20(5):897-911
A slot antenna is developed to excite the high harmonic waveguide mode for generating large-area plasmas. This antenna consists of a TE011 mode coaxial cavity with the axial slots positioned on equal interval on the inner wall. The waves radiated from those slots can excite the high harmonic mode in the central area. With the azimuthal symmetric wave field of the TE011 mode, the number of the slots can be chosen to match the field pattern of the high harmonic mode. In this report, the dispersion relation of the coaxial waveguide, the coupling scheme and the mode competition of the cavity are studied. A method has been successfully developed to suppress the TE121 mode which is the most competing mode to the TE011 mode. 相似文献
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T. Idehara N. Nishida K. Yoshida I. Ogawa T. Tatsukawa D. Wagner G. Gantenbein W. Kasparek M. Thumm 《International Journal of Infrared and Millimeter Waves》1998,19(7):919-930
The cavity of the newest gyrotron, Gyrotron FU IVA in the high frequency series of Fukui University gyrotrons (the Gyrotron FU series) is designed to minimize the mode conversion from the main cavity mode to the higher modes. In this paper, the experimental results are compared with simulations for the complete gyrotron oscillator. The gyrotron has an additional advantage to cover the wide frequency range in submillimeter wave region. 相似文献
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Microwave critical magnetc flux densities Bacc of nearly 160 mT were obtained with a TE011 X-band niobium cavity, these values being higher than the lower critical field Bc1 of the cavity material. 相似文献
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Observation of Mode Patterns for High Purity Mode Operation in the Submillimeter Wave Gyrotron FU VA
T. Idehara I. Ogawa S. Maeda R. Pavlichenko S. Mitsudo D. Wagner M. Thumm 《International Journal of Infrared and Millimeter Waves》2002,23(9):1287-1295
Operation tests of a cavity designed for high purity mode operation of the submillimeter wave gyrotron FU VA has been carried out successfully. The observed emission patterns of several cavity modes appear very pure and are compared with calculated results. High purity mode operation has the advantage of making the conversion to Gaussian-like beams more efficient. 相似文献
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Observation of Mode Patterns for High Purity Mode Operation in the Submillimeter Wave Gyrotron FU VA
T. Idehara I. Ogawa S. Maeda R. Pavlichendko S. Mitsudo D. Wagner M. Thumm 《International Journal of Infrared and Millimeter Waves》2002,23(7):973-980
Operation tests of a cavity designed for high purity mode operation of the submillimeter wave gyrotron FU VA has been carried out successfully. The observed emission patterns of several cavity modes appear very pure and are compared with calculated results. High purity mode operation has the advantage of making the conversion to Gaussian-like beams more efficient. 相似文献
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Optical comb filters based on multi-port fused fiber couplers are proposed and numerically analyzed, 3-arm MZI composed by1fiber splitter and7×33×fiber coupler, and 2-stage cascaded FIR type MZI interleave filter. 相似文献
8.
Hyungbin Son 《光谱学快报》2013,46(2):79-83
The authors present an external cavity diode laser with high spectral purity for tunable laser Raman spectroscopy. To achieve high spectral purity required for Raman spectroscopy, a laser cavity utilizing a volume phase holographic grating, which has very low stray light, is developed and the first-order diffracted beam from the grating is taken as the output. Raman signals can be obtained from common samples with only a commercial laser rejection filter, greatly simplifying a tunable Raman instrument. 相似文献
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A. Grudiev J.-Y. Raguin K. Schünemann 《International Journal of Infrared and Millimeter Waves》2003,24(2):173-187
A time-dependent self-consistent multimode code which allows to model the interaction between the modes of a coaxial cavity gyrotron operating at the fundamental and/or at higher harmonics of the cyclotron frequency is presented. The Method of Moments (MoM) is used to obtain a rigorous solution of the eigenvalue problem for a coaxial waveguide with corrugated insert. It is shown that the use of the Surface Impedance Model for the calculation of modes operating at higher harmonics leads to incorrect results in high-power coaxial cavity gyrotrons. However, the numerical simulations based on the MoM agree well with the available experimental results. 相似文献
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利用旋涂法和真空蒸镀法相结合的方法,根据能量空间传递的原理制备了PVK ∶ Ir(piq)2(acac)体系的红色有机电致发光显示器件。器件的结构为ITO/CuPc/PVK ∶ Ir(piq)2(acac)/BCP/Alq3/LiF/Al。研究了不同主客体掺杂比对器件发光性能的影响,得到了高色纯度、单色性较好的红光器件。当Ir(piq)2(acac)掺杂的质量比为1 ∶ 0.08时,器件的综合性能达到最佳,发光峰位于625 nm,CIE坐标为(x=0.66,y=0.33)。通过对各层厚度的合理选择,形成相对优化的微腔结构,充分利用其对光谱的窄化效应,使得器件的EL光谱的发射半峰全宽仅为55 nm,提高了器件的发光性能。器件光谱具有很好的单色性,色纯度达到98.2%。 相似文献
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杂交稻种宜香725纯度的可见-近红外反射光谱鉴定 总被引:1,自引:0,他引:1
提出了一种基于可见-近红外光谱技术快速、无损鉴定杂交稻种纯度的新方法.以FieldSpec(R)3地物光谱仪采集纯度在90%~99%范围内的杂交稻种(宜香725)光谱数据90份,随机分成校正集(75份)和检验集(15份).根据其在380~2 400 nm的反射光谱,以偏最小二乘算法(PLS)建立了回归模型,并比较了不同光谱预处理方法对模型的影响.分析表明采用一阶导数结合标准归一化处理能最有效地提取光谱信息,此时PLS模型校正集决定系数与检验集决定系数分别为0.988 4与0.922 7,校正标准误差(SEC)与预测标准误差(SEP)分别为0.002 5与0.006 6.将经一阶导数结合标准归一化处理后的光谱进行PCA降维,以前20个主成份(含原始光谱86.09%的特征信息)为输入变量,建立杂交稻种纯度鉴定的BP-ANN模型.分析表明BP-ANN模型校正集决定系数与检验集决定系数分别为0.995 2与0.936 9,SEC与SEP分别为0.001 7与0.006 1,具有比PLS模型更高的精度.结果表明以可见-近红外技术进行杂交稻种纯度的快速、无损鉴定是可行的,且PCA结合BP-ANN是一种优选方法. 相似文献
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CHEN Rongsheng * LIAO Yanbiao 《Chinese Journal of Lasers》2001,10(3):195
Asweknow ,asinglemodefibercouplerisasimplebutveryimportantfiberopticdevice ,whichcanbeusedincommunicationandsensors.Usingsinglemodeopticalfiberdevices,wecanfabricateseveralacoustic opticdevices ,suchasfrequencyshifters ,modulatorsandtunablefilters .Several… 相似文献
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Chen Rongsheng LIAO Yanbiao Zheng Gangtie Liu Tongyu Gerard Franklyn Fernando 《中国光学快报(英文版)》2001,10(3)
This paper reports, for the first time, on the use of a fused-taper single mode optical fiber coupler as a sensing element for the detection of acoustic emission (AE) and ultrasound. When an acoustic wave impinges on the mode-coupling region of a coupler, the coupling coefficient is modulated via the photo-elastic effect. Therefore, the transfer function of the coupler is modulated by an acoustic wave. The sensitivity of the sensor at 140 kHz was approximately 5.2 mV/Pa and the noise floor was 1 Pa. The bandwidth of the sensor was up to several hundred kHz. This AE sensor exhibits significant advantage compared with interferometer-based AE sensors. 相似文献
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I. Ogawa K. Yamada T. Idehara R. Pavlichenko 《International Journal of Infrared and Millimeter Waves》2002,23(2):189-203
In this paper we present a novel design of a quasi-optical system for conversion of gyrotron outputs into Gaussian-like beams. It consists of a quasi-optical antenna, two focusing mirrors and a filter which removes the side lobes of the beam. The system is appropriate as a transmission line for frequency tunable gyrotrons operating at TE0n mode. As an illustration of our approach, we present results which demonstrate the applicability of the developed system for conversion of the radiation generated by the Gyrotron FU IVA. The examples include conversion of three TE0n modes (TE02, 223 GHz; TE03, 323 GHz; TE04, 423 GHz) into Gaussian- like beams. 相似文献
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D. S. Todorovsky K. N. Kostadinov Yu. N. Efremova 《Isotopes in environmental and health studies》2013,49(4):106-107
Radiochemical composition and chemical changes with increasing storage time of benzene solutions and of solid species of elementary 35S with high specific activity are studied. The dependence of the stability on the specific activity and the radioactive concentration is shown and some tentative limits are given for permissible storage periods. 相似文献
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采用交换吸附脱色及柱层析新技术,成功地从烟叶中分离和纯化了一种烟草过氧化物酶同工酶(TOPⅠ),并对其进行了一系列光谱特性研究.基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)测得TOPⅠ分子量为21 888.5,等电点pI为3.5;氨基酸组成分析表明TOPⅠ为一含血红素的酸性蛋白酶.光谱学分析揭示,在402 nm处有一典型的Soret带,在498和636 nm处有特征吸收峰(α,β带),酸度和变性剂对TOPI在紫外可见区的特征吸收峰均产生一定的影响,TOP Ⅰ的荧光光谱测定结果说明TOPⅠ分子中含有Trp残基和Tyr残基以及其自身的独特的光谱学特性. 相似文献
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高纯度烟草过氧化物酶(TOP I)光谱特性研究 总被引:1,自引:0,他引:1
采用交换吸附脱色及柱层析新技术,成功地从烟叶中分离和纯化了一种烟草过氧化物酶同工酶(TOP I),并对其进行了一系列光谱特性研究。基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)测得TOP I分子量为21888.5,等电点pI为3.5;氨基酸组成分析表明TOP I为一含血红素的酸性蛋白酶。光谱学分析揭示,在402nm处有一典型的Soret带,在498和636nm处有特征吸收峰(α,β带),酸度和变性剂对TOP I在紫外可见区的特征吸收峰均产生一定的影响,TOP I的荧光光谱测定结果说明TOP I分子中含有Trp残基和Tyr残基以及其自身的独特的光谱学特性。 相似文献
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Summary A long-pulse (>3 μs) CO2 laser has been built using a negative-branch, frequency-selective, unstable resonator. The results obtained with this device
are shown.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献