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Parallel Techniques for Frame Synchronous Scrambler

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High Technology Letters 1995年第1期1卷 51-54页

作者： Xiaoru, zh. Lieguang, Z. Tsinghua Univ Beijing China

in high speed transmission system such as SDH,parallel scrambling technique is *** paper presents a method of expanding matrix,which makes the traditional ma-trix method capable of realizing parallel scramblers of any size.A novel method called delayoperator method is also described in this *** 8-bit parallel scrambling circuitry ofSDH has been realized with the two methods.

关键词： Parallel scramble Matrix method Delay operator method

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“如果”句功能的类型学考察

汉语学习 2024年第2期 22-32页

作者：吴炳章姜彩璨许冰中国海洋大学外国语学院山东青岛266100

“如果”句的语义结构和用法复杂多样,但学界对该结构的功能类型分析过于笼统。文章通过语料库梳理书面语中“如果”句的结构特点和语篇关系,对其进行了功能分类。从功能视角看,“如果”句在知识域、语言域和人际域中分别发挥前提限定... 详细信息

“如果”句的语义结构和用法复杂多样,但学界对该结构的功能类型分析过于笼统。文章通过语料库梳理书面语中“如果”句的结构特点和语篇关系,对其进行了功能分类。从功能视角看,“如果”句在知识域、语言域和人际域中分别发挥前提限定、语篇建构和会话修辞等功能。根据从句和主句的意义关系,“如果”句可以分为蕴含条件句和非蕴含条件句。各类“如果”句的功能各有句法语义特征。从各类“如果”句的用法分布看,“如果”句的主要功能是表达推理关系,其次是语篇关系,再次是话语修辞。

关键词： “如果”句假设条件句间接条件句

Fabrication of Silicon Quantum Wires by Conventional Silicon Processing

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High Technology Letters 1995年第1期1卷 25-27页

作者： Yi, Sh. Jianlin, L. Feng, W. Rong, zh. Ping, H. Shulin, G. Shunming, zh. Baohua, M. Youdou, zh. Nanjing Univ Nanjing China

Ultra fine silicon quantum wires with the Si/SiO2 heterointerface have been fabricated successfully by using reactive ion etching, anisotropic wet chemical etching and subsequent thermal oxidation. The cross-sectional image of scanning electron microscope shows the silicon quantum wires of high quality with the linewidth down to 20nm. The present method has many remarkable advantages, which is important to the study of low-dimension quantum physics and devices.

关键词： Quantum wire Silicon Silicon dioxide Silicon technique

Sonar image Processing System for an Autonomous Underwater Vehicle(AUV)

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High Technology Letters 1995年第1期1卷 71-75页

作者： Wen, X. Yuling, W. Weiqing, zh. Academia Sinica Beijing China

Sonar image processing system is an important intelligent system of Autonomous Un-derwater *** on TMS320C30 high speed DSP,it is used to realize sonar imagecompression and underwater object detections including obstacle recognition in real *** paper,the software and hardware designs of this system are introduced and the experi-mental results are given.

关键词： Autonomous underwater vehicle Sonar image processing Digital signal processor

Studies of Optical Nonlinearity Behaviors of Ultrafine PbS Particles in Perfluorocarboxylated Cation-exchanged Films

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High Technology Letters 1995年第1期1卷 102-104页

作者： Xiaowen, zh. Xueping, L. Yuan, L. Xurui, X. Songbin, zh. Zongju, X. Yinghua, Z. Academia Sinica Beijing China

Ultrafine PbS particles with different sizes have been prepared in perfluorocarboxylated cation-exchanged films. The variation of PbS particle size was clarified by absorption spectra and TEM graphs. Time-resolved optical Kerr effects were measured by femtosecond pump-probe techniques. Optical Kerr effect response time was estimated to be less than 165 fs. A third-order optical nonlinearity of χ(3)10-12 esu for PbS particles was obtained and it was found that it increases with the decrease of particle sizes, showing the influence of quantum confined effect on optical nonlinear behaviour of ultrafine particles.

关键词： PbS Ultrafine particle Optical nonlinearity Optical Kerr effect

Study on Single-fiber Pull-out Method for Evaluating interfacial Strength in CFRP

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High Technology Letters 1995年第1期1卷 105-108页

作者： Yudong, H. zh.qian, zh. Lixun, L. Qiwei, L. Harbin inst of Technology Harbin China

Single-fiber pull-out testing (SFPOT) methods are frequently used to evaluate the interfacial adhesion between fiber and matrix in composite materials. To make such pull-out measurements, however, the length of embedded fiber must be small enough so that the fiber does not break before it is pulled freely. This is difficult to achieve by conventional methods with fibers of small diameter, such as the carbon fibers. in this paper, a fiber pull-out experiment is described. Specialized apparatus in our laboratory, as well as this technique for sample preparation are discussed in detail. The interfacial shear strength of carbon fiber/resin matrix composites is analyzed quantitatively by using the finite-element method. The SFPOT system has been proved to be an available means for the study of interfacial properties for carbon fiber/resin matrix composites.

关键词： Carbon fiber Composite materials interfacial shear strength Single-fiber pull-out

Designing a practical ATM Campus Network

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High Technology Letters 1995年第1期1卷 61-65页

作者： Bin, L. Yong, zh. Shiduan, Ch. Yan, M. Beijing Univ of Posts and Telecommunications Beijing China

A typical distributed ATM campus network——BUPT(Beijing University of Posts andTelecommunications)ATM Campus Network is presented in this *** network iscomposed of several small ATM switches in a distributed manner and will be connected tothe China Education and Research Network(CERNET).First,an architecture of BUPTATM Campus Network is *** the interworking and protocol conversion be-tween ATM network and existing 802.X LAN are ***,some of the typicalbroadband applications such as multimedia communications,virtual workgroups,remotevideo-teaching and LAN emulation are described.

关键词： ATM Campus network LAN CERNET Broadband services

Soliton Transmission over 50Km at 2.5GHz Repetition Rate

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High Technology Letters 1995年第1期1卷 22-24页

作者： Shan, zh. Minyu, Y. Baoxi, X. Caiyun, L. Jinghui, L. Xin, J. Jiangde, P. Yizh., G. Binkun, zh. Tsinghua Univ Beijing China

A 2.5 GHz optical soliton transmission over 50km has been successfully achieved’for thefirst time in China by using erbium-doped fiber *** soliton pulse width is *** erbium-doped fiber amplifiers are pumped by inGaAs... 详细信息

关键词： Optical soliton Soliton transmission Soliton communication EDFA

Studies on Thermal Conductivity of Diamond Film

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High Technology Letters 1995年第1期1卷 91-94页

作者： Jingbiao, C. Hong, Ch. Jifa, zh. Dayan, B. Rongchuan, F. Univ of Science and Technology of China Hefei China

Diamond films were prepared by electron-assisted chemical vapor deposition (EACVD) system, and the thermal diffusivities of the films with or without substrate were studied by use of photothermal deflection (PTD) technique. The results show that less non-diamond component and larger crystalline size result in higher thermal conductivity of CVD diamond film. The influence of substrate on the measurement of thermal conductivity of the film was investigated, and a simple two-layer heat conduction model is given to account for the influence and used to draw the thermal conductivity of the film from the effective thermal diffusivity of film/substrate system.

关键词： Diamond film Photothermal deflection Thermal conductivity Substrate