声学所发布通信声学突破性技术

中国卫通城市应急联动系统是在一个城市中通过采用统一的报警平台，用于公众报告紧急事件和紧急求助，并整合城市各种应急救援力量及市政服务资源，实现多警种、多部门、多层次、跨地域的统一接警、统一指挥、联合行动。及时、有序、高效的开展紧急救援或抢险救灾活动，从而保障城市共公共安全的综合服务体系及技术集成平台。     

中国卫通推出城市应急联动系统

中国卫通城市应急联动系统是在一个城市中通过采用统一的报警平台，用于公众报告紧急事件和紧急求助，并整合 城市各种应急救援力量及市政服务资源，实现多警种、多部门、多层次、跨地域的统一接警、统一指挥、联合行动。及时、有序、高效的开展紧急救援或抢险救灾活动，从而保障城市共公共安全的综合服务体系及技术集成平台。     

城市应急联动系统和专用移动通信网

为了提高政府对紧急、突发事件的快速反应能力,向市民提供快捷的紧急救助服务,建设城市应急联动系统非常必要.文章提出了城市应急联动系统的组成和实施方案,描述了城市应急联动系统应具有的功能,并指出在应急联动系统中采用数字集群通信系统作为无线移动平台应该是最佳方案,而支持中国自主研制的数字集群通信系统,对发展民族集群通信产业意义深远.     

城市应急与非应急一体化联动系统解决方案

通过建立以城市应急联动系统为主要内容的城市公共安全科技支撑体系，以提高政府对紧急事件快速反应和抗风险的能力，并为市民提供更快捷的紧急救助服务，已成为现代城市管理中迫切需要解决的重大课题。针对这一重大课题，国内外厂商纷纷提出了各具特色的解决方案。其中，亚奥数码有限公司提出了具有前瞻性和实用性的新思路、新方案：“城市应急与非应急一体化联动系统”。     

中国内陆首家应急联动系统南宁市城市应急联动系统的设计构架

城市应急联动是政府协调指挥各相关部门，向公众提供社会紧急求助服务的联合行动。广西壮族自治区南宁市人民政府经过多方面调查研究，经国家批准决定建设“南宁市城市应急联动系统”，将政府各个独立的应急部门有机地结合起来，采用先进、科学、可靠的高科技手段管理城市，提高南宁市城市数字化和信息化的管理水平。国家计委2000年10月正式批准南宁市城市应急联动系统工程立项建设，于2001年5月正式批复该项目的可行性研究报告，使该系统成为迄今为止国家计委批准建设的中国第一套城市应急联动系统。该项目是广西壮族自治区和南宁市的重点项目，也是南宁国家信息化试点城市的龙头工程项目。     

爱立信携手中国卫通为潍坊市提供城市应急联动和社会综合服务系统

近日．由爱立信和中国卫星通信集团公司携手为潍坊市开发的城市应急联动和社会综合服务系统一期工程试运行开通。该系统将有效提高潍坊市的城市综合管理水平，特别是应对突发事件、实现跨部门联动的通信指挥能力。     

爱立信携手中国卫通为潍坊市提供 城市应急联动和社会综合服务系统

近日．由爱立信和中国卫星通信集团公司携手为潍坊市开发的城市应急联动和社会综合服务系统一期工程试运行开通。该系统将有效提高潍坊市的城市综合管理水平，特别是应对突发事件、实现跨部门联动的通信指挥能力。     

南宁市政府与摩托罗拉共建中国第一套城市应急联动系统构筑高效应急系统打造一流现代城市

２００１年１１月１１日,广西南宁市与世界无线通信巨头摩托罗拉共同打造的中国第一套城市应急联动系统在南宁投入试运行。国家计委、信息产业部、广西壮族自治区、南宁市以及摩托罗拉（中国）电子有限公司等单位的领导出席了应急联动中心的揭幕仪式。该系统的建成标志着中国城市在应急管理水平和信息化建设上的新突破。随着中国加入世界贸易组织并在管理模式上逐步与国际接轨,这种运用高科技管理城市的方法必然被越来越多地引入中国,从而推动中国城市的现代化步伐。城市应急联动系统就是综合各种城市应急服务资源,统一指挥、联合行动,…     

我国城市应急联动通信系统将形成数百亿市场

5月25日，“2006城市应急联动通信高层研讨会”在京召开。会议就城市应急联动系统建设的挑战与应对，我国城市应急机制存在的主要问题，我国城市应急联动的主要需求、管理规划，城市应急联动的建设思路以及应急联动建设模式等几个方面进行了研究和探讨。与会人士一致认为，建设好一个城市应急联动系统，将会帮助政府提高对各种突发事件的反应和处理，以及抗风险能力，对减少灾害损失，更好地为百姓服务起到关键作用，也为建立公众服务型政府打好坚实基础。     

基于CERS的接处警系统的设计与应用

针对当前城市应急联动系统（CERS）在中小城市的快速发展和应用,其中接处警系统是城市应急联动系统的重要组成部分,为提高系统的稳定性,通过分析当前城市应急联动系统的基本结构,研究设计出适合现代社会应急需求的接处警系统的整体结构、系统的主要功能以及接处警流程,并进行了应用方面的分析研究,为城市应急联动系统的建设提供了很好的指导作用.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Call for Papers

正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its