一种多输入队ATM交换结构

本文提出一种多输入排队ＡＴＭ交换结构和相应的输出冲突解决方法，它可以使交换网络避免输入队固有的排头阻塞，从而使网络在不增加运行速率的情况下，可达到输出排队的性能。文中介绍了冲突解决办法及其实现技术，说明它可方便地在高速网中实现。     

A KBES for integrated engineering

The expert process of engineering involves application of knowledge fundamental to the engineering process at one end, and of compiled knowledge in the form of heuristics gained through many years of experience at the other. Developments in Artificial Intelligence have made the process of computer aided engineering richer by enabling the simulation of this human process of engineering, which until now has been difficult to capture. Knowledge Based Expert Systems (KBES) in engineering developed so far have addressed only narrow domains of the entire process of engineering. This paper discusses a KBES shell (IES) that integrates various AI technologies, which makes it possible to implement new problem-solving strategies required for efficient handling of the entire engineering process. Issues in the integrated process of engineering are discussed first, in order to evolve a specification for the shell. The blackboard architecture is shown to be the ideal backbone for such a shell. The details of inference techniques, the knowledge based backtracking mechanism and the DBMS used in the IES are presented. The application of the IES is demonstrated using the domain of integrated engineering of steel industrial structures as an example. This application encompasses the engineering activities of conceptual design, detailed design, documentation and construction planning.     

黄土塬区天然气地震技术和综合解释

黄土塬区复杂的地表条件难以获得可供解释的物探资料,本文给出了勘探天然气的地震技术,在野外弯线地震数据采集中,冲沟区运用了弯线高分辨率技术;塬上区采用非纵测线和地震测深观测系统,大药量、深井和强化组合法的接收条件。初步解决了弯线地震资料处理中二维滤波、静校正、速度分析等技术难题。摸索出一套以地震为骨架,构造解释与岩性解释相结合,重力-电法-地震联合解释落实古生界天然气构造圈闭的综合物探解释技术,并以实例展示方法的有效性。     

Novel miniature integrated optical goniometers

A new principle and arrangement for directly determining the angle of incidence of an optical beam on an object are proposed and demonstrated. The novelty of the approach lies in the realization of a ‘smart object’, which extracts a portion of the incident beam's power into an optical waveguide attached to the object's surface or embedded in its body for converting the angle of incidence into the position of a guided beam with finite lateral extent. This ‘integrated optical light pointer’ beam is accomplished by means of creating additional degrees of freedom on the target in two different ways. While a first type is based on introducing spatial variations of the waveguide thickness, a second type makes use of a chirp of the grating periodicity. The feasibility for practical applications has been experimentally demonstrated by a direct comparison with a commercial high-resolution encoder, resulting in an r.m.s. error of <30′'. Measurements have been performed for chips fabricated based on replicated polycarbonate substrates and with no external optics, showing the great potential of this approach for realizing low-cost yet high-performance miniature goniometers.     

高性能2.5Gb／s用的DFB—LD／EA单片集成器件

报导了采用全ＭＯＣＶＤ生长的１．５５μｍ的单片集成ＤＦＢ＝ＬＤ／ＥＡ组件的 在ＤＷＤＭ系统上的传输测试结果，出纤功率Ｐｆ≥２．５ｍＷ＠Ｉｆ＝７５ｍＡ，边模抑制比ＳＭＳＲ〉３５ｄＢ，调制器反向偏压为２．５Ｖ时的消光比为１４ｄＢ，该发射模块在２．５Ｇｂ／ｓＤＷＤＭ系统上进行了传输试验，传输２４０Ｋｍ后无误码，其通道代价≤１ｄＢ＠ＢＥＲ＝１０＾－１２。     

An integrated system of biological and catalytic oxidation for the removal of o-xylene from exhaust

Biofiltration is an efficient technology for treatment of gaseous waste. Its disadvantages, however, include large volume of bioreactor and slow adaptation to fluctuating concentrations in waste gas. Catalytic oxidation offers a high destructive efficiency at relatively low operating temperature and small unit. A bench scale system integrated with a biofilter and a catalytic oxidation unit for the treatment of gases containing o-xylene was investigated in this study. The catalytic oxidation unit was packed with Cu/Al₂O₃ catalyst. The results showed that 90% of o-xylene could be removed in the biofilter at the load below 38.2 g m⁻³ h⁻¹. High o-xylene concentration in inlet gas resulted in an overload of the biofilter. Using the Cu/Al₂O₃ catalytic oxidation unit, the concentration of o-xylene could be reduced evidently. The combination of the chemical and microbial processes not only led to a high and stable efficiency of o-xylene conversion, but also improved capacity resisting the shock loads. The Cu/Al₂O₃ was studied for o-xylene oxidation in temperature range of 90–320 °C. The o-xylene conversion was improved correspondingly with the increasing of oxidation temperature. The reaction mechanism of o-xylene oxidation on Cu/Al₂O₃ was also investigated using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS).     

Growth and characterization of GaAs films deposited on Ge/Si composite substrates by metalorganic chemical vapor deposition

We report the results of studies which have been made on heteroepitaxial layers of GaAs and AlGaAs grown by metalorganic chemical vapor deposition on composite substrates that consist of four different types of heteroepitaxial layered structures of Ge and Ge-Si grown by molecular beam epitaxy on (100)-oriented Si substrates. It is found that of the four structures studied, the preferred composite substrate is a single layer of Ge ∼1 μm thick grown directly on a Si buffer layer. The double-crystal X-ray rocking curves of 2 μm thick GaAs films grown on such substrates have FWHM values as small as 168 arc sec. Transmission electron micrographs of these Ge/Si composite substrates has shown that the number of dislocations in the Ge heteroepitaxial layer can be greatly reduced by an anneal at about 750° C for 30 min which is simultaneously carried out during the growth of the GaAs layer. The quality of the GaAs layers grown on these composite substrates can be greatly improved by the use of a five-period GaAs-GaAsP strained-layer superlattice (SLS). Using the results of these studies, low-threshold optically pumped AlGaAs-GaAs DH laser structures have been grown by MOCVD on MBE Ge/Si composite substrates.     

Development of High Thermal Conductivity Aluminum Nitride Ceramic

AIN ceramics with densities varying from 3.18 to 3.30 g/cm³ and room-temperature thermal conductivities varying from 88 to 193 W/m K were produced. Different sintering conditions, packing powders, AIN powder sources, carbon additive, and sintering times were evaluated, and the key processing parameters which cause the differences in density and thermal conductivity were identified. SEM, TEM, and EDS were used to characterize the correlation between thermal conductivity, microstructure, and processing parameters. The important parameters which control the thermal conductivity of AIN ceramics are discussed.     

卫星遥感测控的系统融合技术

卫星遥感测控系统包括运载火箭飞行测控，卫星运行测控，有效载荷设备测控以及它本身应完成的遥感测量，高效完备的系统融合技术采用包括视频综合技术，统一载波宽带传输技术，地面站多功能统一测控技术，软件化技术，载波综合利用技术等，大大简化了卫星遥感的测控设备。