首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 781 毫秒
1.
二维光子晶体平行多波导的传输光谱研究   总被引:2,自引:2,他引:0  
采用时域有限差分法研究二维光子晶体两平行直波导以及三平行直波导的传输特性。计算结果表明,两平行波导在不同的频率范围内表现出不同的耦合特性:在高频段两波导表现出相互的能量交换,实现光耦合,而在低频段传输谱图重合,各波导传输光强均为入射光强的二分之一;对于三波导系统,发现在不同的频率范围内主波导与两耦合波导之间也表现出不同的耦合特性:在高频段两耦合波导与主波导实现光耦合,而在低频段两耦合波导与主波导的传输谱图同步变化,耦合波导的传输光强均约为入射光强的四分之一。  相似文献   

2.
代红权  吴耀德 《光谱实验室》2009,26(5):1372-1374
设计一种喇叭型开口二维光子晶体波导,利用时域有限差分法计算波导传输谱图。模拟结果表明:通过改变开口处光子晶体椭圆点缺陷的结构,传输谱图中将出现相应变化的缺陷模,可用于实现频率可调的窄带光子晶体滤波器。  相似文献   

3.
红外光谱在仿古玉石鉴定中的应用   总被引:1,自引:0,他引:1  
申柯娅 《光谱实验室》2010,27(4):1393-1398
采用常规宝石学研究方法和红外吸收光谱技术,对市场上常见的仿古玉石进行了研究。红外吸收光谱测试结果表明:市场上常见的仿古玉石,主要为软玉(和田玉)、岫玉和石英质玉石组成。不同种类的仿古玉石,其红外吸收光谱特征存在着明显的差异:软玉在996、463cm-1附近;岫玉在1047、471cm-1附近,并在3665cm-1附近有明显的水的吸收峰;石英质玉石在1106、481cm-1附近。通过红外吸收光谱的测定和分析,可以准确鉴定仿古玉石的玉石品种。  相似文献   

4.
XYZ particles at Belle   总被引:1,自引:0,他引:1  
沈成平   《中国物理 C》2010,34(6):615-620
In this paper, I review recent progress in the study of the XYZ particles at Belle. I only focus on studies with charmonium and one or more light mesons in the final states. This covers the X(3872), X(3915), Y(4140), X(4350), and the charged Z states.  相似文献   

5.
The dressed four-wave mixing (FWM) in a four-level S5Rb atomic system, experimentally demon- strated in this paper, is comprised by two coexisting processes. One is emission signal due to enhanced nonlinear via electromagnetically induced transparency (EIT). The other is the Bragg reflection of probe beam because of the created photonic band gap (PBG), which is affected by both linear and third-order nonlinear susceptibility. Moreover, we have demonstrated that different experimental parameters can significantly influence the measured signal with flexibly controlled PBG. These studies are found useful for understanding the fundamental mechanisms in generated FWM processing.  相似文献   

6.
沈成平  苑长征 《中国物理 C》2010,34(8):1045-1051
A combined fit is performed to the BABAR and Belle measurements of the e^+e^- →φπ^+π^- and φf0(980) cross sections for center-of-mass energy between threshold and 3.0 GeV. The resonance parameters of the φ(1680) and Y(2175) are determined. The mass is (1681-12^+10) MeV/c^2 and the width is (221-24^+34) MeV/c^2 for the φ(1680), and the mass is (2117-49^+59) MeV/c^2 and the width is (164-80^+69) MeV/c^2 for the Y(2175). This information will shed light on the understanding of the nature of the excited φ and Y states observed in e+e- annihilation.  相似文献   

7.
李卫青 《物理学报》2009,58(9):6530-6533
利用等离子体增强脉冲激光沉积系统在Si(100)基底上沉积出了高质量的o-BN薄膜,利用红外光谱(FTIR)、X射线衍射谱(XRD)和原子力显微镜照片对o-BN薄膜进行了表征.通过红外光谱(FTIR)得到o-BN薄膜的红外峰特征峰值为1189cm-1,1585cm-1和1450cm-1;由XRD谱得到o-BN薄膜的(111),(020),(021),(310)和(243)各晶面的衍射峰, 特别是(310)和(243)晶面的衍射峰非常强;通过原子力显微镜照片清楚看到BN薄膜具有尖状突起的表面形貌. 关键词: 等离子体增强脉冲激光沉积 氮化硼薄膜 X射线衍射谱  相似文献   

8.
电镀废水中Cr(Ⅵ)的次甲基蓝分光光度法研究   总被引:1,自引:0,他引:1  
在H2SO4溶液中,以次甲基蓝(MB)为显色剂,利用铬(Ⅵ)与次甲基蓝(MB)在水浴加热条件的显色反应,建立了一种测定电镀废水中微量铬(Ⅵ)的新光度法。反应产物的最大吸收波长为573nm,摩尔吸光系数为1.40×10^4L·mol^-1·cm^-1,检出限为2.4×10^-7g·mL^-1,铬(Ⅵ)含量在10—50μg/25mL范围内有良好的线性关系,相关系数为0.9991,用于测定电镀废水中的微量铬(Ⅵ),加标回收率为97.5%—104.5%,相对标准偏差≤0.46%。  相似文献   

9.
10.
通过荧光光谱法研究了铕(Ⅲ)、铽(Ⅲ)两种稀土离子对四(3,4-亚甲二氧基苯基)卟啉(TMPP)荧光强度的影响.在中性介质中,铕(Ⅲ)和铽(Ⅲ)与TMPP相互作用使TMPP的荧光猝灭.实验表明:以DMF为溶剂、420 nm为最大激发波长、655nm为最大发射波长时,TMPP的荧光强度和稀土离子对其荧光猝灭均达到最大值.  相似文献   

11.
The high level quantum chemistry ab inito multi-reference configuration interaction (MRCI) method with large V5Z basis set is used to calculate the spectroscopic properties of the 15 A-S electronic states (X1∑+, A I П, 1 △, 1 ∑, 3∑+, 3П, 3△, 3△ , 5∑+, 5П, 5△, 1П (II), ofAsO+ radical correlated to the dissociation limit As+(3pg) + O(3pg) and As+(IDg) + O(1Dg). In order to obtain better potential curves and more accurate spectroscopic properties, the Davidson modification is taken into account. With the potential energy curves (PECs) determined here, vibrational levels G(v) and inertial rotation constants Bu are computed for all the bound electronic states when the rotational quantum number J equals zero (J = 0). Except for the states X1∑+, A1П , it is the first time that the multi-reference configuration calculation has been used on the 13 A-S electronic states of the AsO+ radical. The potential energy curves of all the A-S electronic states are depicted according to the avoided crossing rule of the same symmetry. Spin-orbit coupling effect (SOC) is introduced into the states X1 ∑+, A1 П, 3П to consider its effects on the spectroscopic properties. Transition dipole moments (TDMs) from A1П 1, 3 П1 states to the ground state X1∑0+ are predicted as well.  相似文献   

12.
分析了里德-所罗门码(RS码)的误码率性能,提出了一种基于RiBM算法的RS(15,9)译码器。该译码器采用流水线结构,通过RiBM算法求解关键方程,在此基础上将高斯加性白噪声(AWGN)引入光纤模拟大气激光通信系统,并在现场可编程门阵列(FPGA)平台上完成了测试。测试结果表明:提出的译码器译码速率达到1.11 Gbit/s,为Altera IP核的3.54倍。RiBM算法具有硬件复杂度低、关键路径延时短的优点,能满足系统译码的要求。  相似文献   

13.
Based on the nonrelativistic QCD factorization approach, O(αsv2) corrections to J/ψ plus ηc production in e+e- annihilation at √s= 10.6 GeV are calculated in this work. The numerical results show that the correction at αsv2 order is only about a few percent of the total theoretical result. This indicates that the perturbative expansions become convergent and that a higher order correction will be smaller. The uncertainties from the long-distance matrix elements, renormalization scale and the measurement in the experiment are also discussed. Our result is in agreement with the previous result by Jia.  相似文献   

14.
We introduce the so-called coherent-entangled state (CES) in the four-mode Fock space, which makes up a new quantum mechanical representation owing to completeness relation and orthogonal property. Its standard Schmidt decomposition and experimental generation using beam-splitter (BS) are proposed. In addition, its applications in quantum optics are presented. Finally, we extend it to multi-mode case and discuss some applications, too.  相似文献   

15.
Klaus Gö  tzen 《中国物理 C》2010,34(6):638-643
The BES-Ⅲ Detector is a very versatile multipurpose device located at the Institute of High Energy Physics (IHEP) in Beijing, China. Concerning the physics program it ties stringently up to the past BES and BES-Ⅱ experiments. Since start of the data taking in the middle of 2008 the accumulated dataset of 200.10^6 J/ψ events and 100.10^6 ψ' events already exceeds the world data on these resonances. In addition to studies of the charmonium systems the data offers great opportunity for investigations in the light hadron sector. In detail it will be reported about the confirmation of the enhancement in pp invariant mass in radiative J/ψ decays, the search for decays Y(2175) → K*0K*0, observation of a charged K^± in K^±π^0 and observation of a new excited baryon N*(2065) decaying to pπ^0 and charged onjugate. The first result is based on data taken by BES-Ⅱ and BES-Ⅲ, the latter three on data collected by BES-Ⅱ only.  相似文献   

16.
Quantum correlation, measured by measurement-induced disturbance (MID), between two two-level atoms is investi- gated in detail in Tavis-Cummings model with dipole--dipole interaction (DDI). We find that MID can be determined only by the dipole-dipole interaction between the two atoms when the cavity and atoms are at resonance. Moreover, DDI will have different effects on MID for two different kinds of initial states.  相似文献   

17.
The ionization process of B2+ by H+ impact is studied using the continuum-distorted-wave eikonal-initial-state (CDW-EIS) method and the modified free electron peak approximation (M-FEPA), respectively. Total, single-, and double- differential cross sections from 1s and 2s orbitals are presented for the energy range from 10 keV/u to 10 MeV/u. Comparison between the results from the two methods demonstrates that the total and single-differential cross sections for the high-energy incident projectile case can be well evaluated using the simple M-FEPA model. Moreover, the M-FEPA model reproduces the essential features of the binary-encounter (BE) bump in the double-differential cross sections. Thus, the BE ionization mechanism is discussed in detail by adopting the M-FEPA model. In particular, the double- and single-differential cross sections from the 2s orbital show a high-energy hip, which is different from those from the 1s orbital. Based on Ref. [1], the Compton profiles of B2+ for 1s and 2s orbitals are given, and the hips in DDCS and SDCS from the 2s orbital are explained.  相似文献   

18.
In this paper, we present numerically and experimentally the linear beam-optics distortion in the SSRF storage ring and the correction of optics by using a number of quadrupole magnets installed in the storage ring. The measured orbit-response matrices were fitted to the model-response matrices to obtain the β and the dispersion functions in the storage ring. By readjusting the currents of quadrupole-magnet power supplies, we were able to successfully restore the optics parameters to values very close to the design ones, with rms deviations around 1%. This periodicity restoration is verified with the β function measurement.  相似文献   

19.
L波段双频磁绝缘线振荡器的实验研究   总被引:1,自引:0,他引:1       下载免费PDF全文
根据角向分区产生双频率高功率微波(HPM)的设计思路,开展了基于谐振腔深度角向分区模型的L波段双频磁绝缘线振荡器(BFMILO)的实验研究,建立了BFMILO的实验系统和测量系统,热测了BFMILO的辐射方向图,通过辐射场功率密度积分得到了输出微波的功率.在电子束电压约为420kV,管电流约为34kA的条件下,L波段BFMILO输出的微波频率分别为1.26GHz和1.45GHz,对应的微波功率分别为398MW和222MW.并初步得到了谐振腔深度的角向分区比例不同的BFMILO的初步实验结果.实验研究得到了 关键词: 角向分区 磁绝缘线振荡器(MILO) 双频MILO(BFMILO) 高功率微波(HPM)  相似文献   

20.
The initial single pion emission (ISPE) mechanism is applied to the processes r(5S)→πB(*)B-(*), whose details have been recently reported at ICHEP2012, and we obtain reasonable agreement with Bell's measurements; that is, we succeed in reproducing the enhancement structures of Zb(10610) and Zb(10650). Inspired by this success, we also predict the corresponding enhancement structures in open charm oue-pion decays of higher charmonia near the thresholds of D*D- and D*D-*.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号