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141.
修晓明  董莉  高亚军  迟锋 《中国物理》2007,16(8):2194-2199
In this paper a controlled quantum teleportation scheme of an N-particle unknown state is proposed when N groups of three-particle W1 states are utilized as quantum channels. The quantum information of N-particle unknown state is transmitted from the sender to the recipient under the control of all supervisors. It can be realized with a certain probability. After the sender makes Bell-state measurements and the supervisors perform the computational basis measurements, the recipient will introduce auxiliary particles and carry out unitary transformations depending on classical information from the sender and the supervisors. Finally, the computational basis measurement will be performed by the recipient to confirm whether the teleportation succeeds or not. The successful completion of the scheme relies on all supervisors' cooperation. In addition, the fidelity and security of the scheme are discussed.  相似文献   
142.
PIV水下流场测试系统试验研究   总被引:1,自引:0,他引:1  
胡海豹  宋保维  阮驰  杜晓旭  毛昭勇 《光子学报》2007,36(10):1928-1932
基于粒子图像测速技术,设计研制了一套适用于水洞洞体内高速、封闭试验条件的流场测量与显示设备.该系统由光源、成像、图像处理与分析、控制和粒子投放等分系统组成,具有复杂环境下全流场的无接触、无扰动、高准确度测量和显示能力,流场测试误差小于2%,可为水下航行器外形设计及其改进提供相关的实测数据.  相似文献   
143.
A tantalum pentoxide‐based (Ta2O5‐based) micro‐ring all‐optical modulator was fabricated. The refractive index inside the micro‐ring cavity was modified using the Kerr effect by injecting a pumped pulse. The transmittance of the ring resonator was controlled to achieve all‐optical modulation at the wavelength of the injected probe. When 12 GHz pulses with a peak power of 1.2 W were coupled in the ring cavity, the transmission spectrum of the Ta2O5 resonator was red‐shifted by 0.04 nm because of the Kerr effect. The relationship between the modulation depth and gap of the Ta2O5 directional coupler is discussed. An optimized gap of 1100 nm was obtained, and a maximum buildup factor of 11.7 with 84% modulation depth was achieved. The nonlinear refractive index of Ta2O5 at 1.55 μm was estimated as 3.4 × 10?14 cm2/W based on the Kerr effect, which is almost an order of magnitude higher than that of Si3N4. All results indicate that Ta2O5 has potential for use in nonlinear waveguide applications with modulation speeds as high as tens of GHz.

  相似文献   

144.
A novel stable energetic compound (E)‐1,2‐diamino‐1,2‐dinitrodiboron (DANB) was theoretically designed based on the structure of 1,1‐diamino‐2,2‐dinitroethene (FOX‐7). Atomization method in combination with Hess' law was used to predict the heat of formation. The detonation velocity (D) and detonation pressure (P) of DANB were approximatively estimated by using Kamlet–Jacobs equations. As a result, DANB has huge heat of formation (2013.5 kJ/mol) and specific enthalpy of combustion (?26.4 kJ/g). Furthermore, DANB possesses high crystal density (1.85 g/cm3) and heat of detonation (5476.0 cal/g), which lead to surprising detonation performance (D = 10.72 km/s, P = 51.9 GPa) that is greater than those of FOX‐7 (D = 8.63 km/s, P = 34.0 GPa) and CL‐20 (D = 9.62 km/s, P = 44.1 GPa). More importantly, DANB is very stable because its bond dissociation energy of the weakest bond (BDE = 357.8 kJ/mol) is larger than those of the most common explosives, such as FOX‐7 (BDE = 200.4 kJ/mol), CL‐20(BDE = 209.2 kJ/mol), HMX(BDE = 165.7 kJ/mol), and RDX (BDE = 161.4 kJ/mol). Therefore, our results show that DANB is a promising candidate for stable and powerful energetic material.  相似文献   
145.
In this paper, a novel strategy for the fabrication of reduced graphene oxide (rGO)/Cu8S5/polypyrrole (PPy) composite nanosheets with Cu8S5 nanoparticles and PPy layer anchored on the surface of rGO as peroxidase‐like nanocatalyst is reported. During the synthesis, graphene oxide (GO)/CuO composite nanosheets are prepared first and used as templates, then the sulfuration of CuO and polymerization of pyrrole are accompanied with the reduction of GO, resulting in ternary rGO/Cu8S5/PPy composite nanosheets. The synthesized Cu8S5 nanoparticles with a diameter in the range from tens to hundreds of nanometers are dispersed within PPy decorated rGO nanosheets. The resultant ternary rGO/Cu8S5/PPy composite nanosheets exhibit a higher peroxidase‐like catalytic activity toward the oxidation of 3,3′,5,5′‐tetramethylbenzidine in the presence of H2O2 than GO/CuO and rGO/CuS composite nanosheets, revealing a synergistic effect on their activity. The as‐prepared rGO/Cu8S5/PPy platform provides a simple colorimetric approach for the detection of H2O2 and phenol with a high sensitivity. This work offers a new way for the fabrication of rGO‐based nanocomposite with superior enzyme‐like activity, which displays great potential applications in biocatalysis and environmental monitoring.  相似文献   
146.
利用可调谐半导体激光吸收光谱技术(TDLAS)并结合波长调制,在近红外波段1531.7nm处对常温常压下的NH3进行浓度测量.在10 m的长程吸收池内得到了25×10-6的浓度信号,并且在25×10-5-400×10-6浓度范围内二次谐波信号与浓度具有良好的线性关系.讨论了粉尘颗粒对于二次谐波信号的干扰,并提出了利用激光强度线性拟合解决颗粒对气体测量干扰的方法.  相似文献   
147.
Wong WC  Chan CC  Chen LH  Tou ZQ  Leong KC 《Optics letters》2011,36(9):1731-1733
A highly sensitive miniature photonic crystal fiber refractive index sensor based on field mode excitation is presented. The sensor is fabricated by melting one end of a photonic crystal fiber into a rounded tip and splicing and collapsing the other end with a single-mode fiber. The rounded tip is able to induce cladding mode excitation, which resulted in an additional phase delay. Linear response of 262.28 nm/refractive index unit in the refractive index range of 1.337 to 1.395 is obtained for the physical length of a 953 μm sensor. The sensor is also shown to be insensitive to environmental temperature.  相似文献   
148.
Lee CC  Chi S 《Optics letters》2000,25(24):1774-1776
A fiber Bragg grating- (FBG-) based fiber-ring laser that utilizes the transmitted light of the FBG as self-injection feedback for single-longitudinal-mode (SLM) oscillation is proposed and demonstrated. This laser is simply constructed by means of feeding back the transmitted light of the FBG and is coupled into the main ring cavity through an optical coupler. The self-injection feedback is the key to ensuring SLM laser oscillation. The SLM operation principle is discussed in detail, and a SLM laser with output power of 6.6 dBm, an optical signal-to-noise ratio of 57 dB at 1549.19 nm, and a short-term linewidth of 3.5 kHz is reported.  相似文献   
149.
Making use of the relativistic BBGKY technique,the relativistic generalization of Landau collision integral is botained.Furthermore,we calculate the relativistic hydrodynamic modes up to the second order in the hydrodynamic wave number.Combining Resibois‘ method,we present the first principle formula of the relativistic heat conductivity of Coulumb electronic plasmas for low-order corrections.  相似文献   
150.
该文对连续动力系统研究了Devaney意义下的混沌的不变性质.证明了:(1)半流是混沌的(resP,ω混沌的)当且仅当它的逆极限是混沌的(resp,ω混沌的);(2)自映射是混沌的(resp.ω混沌的)当且仅当它的扭扩半流是混沌的(resp.ω混沌的);(3)自映射逆极限的扭扩流拓扑共轭于其扭扩半流的逆极限.从(2)和(3)可知,结论(1)是对自映射的推广.  相似文献   
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