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101.
李超 《世界电信》1994,7(4):19-20,40
分片汇接的网状网结构是江苏省本地电话网的基本框架,而汇接局和连接汇接局的传输系统则是网路规划与通信建设的重点。  相似文献   
102.
103.
We characterize orbifolds in terms of their sheaves, and show that orbifolds correspond exactly to a specific class of smooth groupoids. As an application, we construct fibered products of orbifolds and prove a change-of-base formula for sheaf cohomology.  相似文献   
104.
In situ measurements of gas-liquid surface reactions of single aerosol microdroplets are presented. By means of optical levitation in combination with elastic (Mie) and inelastic (Raman) light scattering it is possible to get information on the chemistry of e.g. acid/base reactions as well as the physical behavior of single microparticles.  相似文献   
105.
I.IntroductionWhenastructurcvibratcs,itsvibratingsurfacewillmakesurroundingmediummovetogethcrwithit.Ifthernotionissofastthatthcmediumroundthestructureproduccaloca1contractionandcxpansionandthcypropagatefaraway,thesoundradiationisformed.Itispossiblctodcscribeanalytica11ytheradiationfic1dofsimplyandregularlyshapcdsourcessuchaspointsoundsourccs,spherica1soundsourccsandinflnite1engthllnearsoundsourccs,butitisa1mostimpossib1ctosolvetheradiationfiledbyanyanalyt-ica1methodforsourcesofvcrycomplicateds…  相似文献   
106.
We describe a general method that enables us to obtain all the singular terms of helicity amplitudes of n-parton processes at one loop. The algorithm uses helicity amplitudes at tree level and simple color algebra. We illustrate the method by calculating the singular part of the one-loop helicity amplitudes of all 2 → 3 parton subprocesses. The results are used to derive the soft gluon limit of the cross sections of all 2 → 4 parton scattering subprocesses which provide a useful initial condition for the angular ordering approximation to coherent multiple soft gluon emission, incorporated in existing Monte Carlo simulation programs.  相似文献   
107.
Summary The first wall of the fusion device TEXTOR at the Forschungszentrum Jülich has been coated in situ with an amorphous hydrogen rich carbon/boron film (a-C/B:H) which reduces plasma impurities caused by the plasma surface interaction. The results of the coating process of the 35 m2 large inner wall surface have been controlled by a recently developed modification of the quantitative electron probe microanalysis, which has been applied to 12 samples from specified positions inside the tokamak. The quantification itself is based on a Monte Carlo simulation of electron trajectories providing very accurate results for X-ray intensities emitted by elements present in the electron bombarded sample. The Monte Carlo results are used in the present work to calibrate the measured X-ray intensities emitted by boron and carbon from the a-C/B:H layers deposited on pure silicon substrates. As a result the total deposited mass of the layer per area unit as well as the composition of the layers (except hydrogen) could be determined very accurately. The relative errors were less than 7%. The limit of detectability were found to be in the range of one monolayer for boron as well as for carbon.  相似文献   
108.
In this paper, we present efficient VLSI architectures for full-search block-matching motion estimation (BMME) algorithm. Given a search range, we partition it into sub-search arrays called tiles. By fully exploiting data dependency within a tile, efficient VLSI architectures can be obtained. Using the proposed VLSI architectures, all the block-matchings in a tile can be processed in parallel. All the tiles within a search range can be processed serially or concurrently depending on various requirements. With the consideration of processing speed, hardware cost, and I/O bandwidth, the optimal tile size for a specific video application is analyzed. By partitioning a search range into tiles with appropriate size, flexible VLSI designs with different throughput can be obtained. In this way, cost effective VLSI designs for a wide range of video applications, from H.261 to HDTV, can be achieved.  相似文献   
109.
孟洛明 《世界电信》1996,9(4):25-27
本文叙述了智能网的业务管理系统所实现的3种功能:业务管理功能,网络管理功能和业务管理访问功能,还介绍了业务管理和网络管理之间的关系,SMS的集中式和分布式两种体系结构及业务管理功能的设计方法和进一步研究方向。  相似文献   
110.
王界平  王清平 《微电子学》1996,26(3):150-152
SOI材料的全介质隔离技术与高频互补双极工艺的结合是研制抗辐照能力强、频带宽、速度高的集成运算放大器的理想途径,从实验的角度提出了一种SOI材料全介质隔离与高频互补双极工艺兼容的工艺途径。  相似文献   
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