Φ9.5m级2219铝合金环件整体形-性协同极限制造技术与应用

为解决Φ9.5 m级2219铝合金整体过渡环研制难题,提出了铸锭制备、环坯制备、环轧成形各个环节精准控制策略,形成了大规格环件整体形-性协同极限制造技术路线,并成功试制出Φ9.5 m级超大规格2219铝合金环件,获得了均匀细化的微观组织结构和优异的综合性能.锻环微观组织均匀,未出现明显各向异性,无粗大残余结晶相聚集,晶...     

克劳斯装置中温有机硫水解催化剂研究

针对硫磺回收装置克劳斯二级反应器有机硫水解率较低的问题,采用新型共浸技术研发了中温有机硫水解催化剂。考察了催化剂的耐硫性能及温度对催化剂性能的影响。实验结果表明,在220~300℃的温度范围内,催化剂表现出较高的有机硫水解性能;且在H_2S、SO_2、CS_2体积分数变化的范围内,均优于现阶段二级反应器中装填的活性氧化铝催化剂。     

REGIONAL 3D MODELLING OF THE PERMO‐CARBONIFEROUS AL KHLATA FORMATION IN THE RIMA AREA,EASTERN FLANK OF THE SOUTH OMAN SALT BASIN

The glaciogenic Al Khlata Formation (Late Carboniferous – Early Permian) contains important reservoir and seal intervals in oil fields in southern Oman. Here we describe a 3D regional geological model of the Al Khlata Formation and the underlying Misfar Group in a 1750 km² area in the Eastern Flank of the South Oman Salt Basin. The Misfar Group (Devonian‐Carboniferous?) was included in the model because it also contains glaciogenic facies in the study area. The 3D model is based on wireline logs from 42 wells, palynological zonation in 31 wells, cores from three wells, and a 2011 3D seismic dataset from which three horizons (top‐Huqf, top‐Rahab Shale and top‐Gharif) were interpreted throughout the study area. The combined Al Khlata and Misfar interval varies in thickness in the area from 20 to 730 m over relatively short distances. These large variations in thickness were due to the creation of accommodation in mini‐basins resulting from the removal of underlying Infracambrian salt at the basin margin. In places, some of the available accommodation was occupied by Cambrian sandstones of the Nimr Group and Haima Supergroup, influencing the location and thickness of the Al Khlata mini‐basins. These local depocentres vary in scale, shape and orientation relative to the present‐day salt edge: some are ovoid in plan‐view, others more linear and parallel to the salt edge, and one takes the form of a narrow graben almost perpendicular to the salt edge. By the Early Permian, towards the end of Al Khlata time, deposits become more blanket‐like and uniform, indicating an external or more regional control on base level. Four key lithofacies have been distinguished from wireline logs and were populated zone‐by‐zone through the geological model: sandstone (reservoir), shale (seal), and sandy and silty diamictite. Sandstones are most common towards the base of the Misfar – Al Khlata interval and shales towards the top. The Rahab Shale (Early Permian) at the top of the Al Khlata Formation forms an important seal for oil fields in South Oman, often in combination with seals in overlying intervals. The Rahab Shale was the first widespread seal to be deposited which may have trapped oil migrating from the South Oman Salt Basin during the Palaeozoic. The most common lithofacies in the Misfar – Al Khlata interval in the modelled area is diamictite (60%), which is normally considered to be a waste‐rock lithology. However thick silty diamictites of sufficient extent can seal hydrocarbon accumulations, and some sandy diamictites have the potential to be unconventional reservoir rocks. Even after 50 years of exploration and production of oil from the Al Khlata Formation, there remains potential for further discoveries and overlooked pay zones due to its heterogeneous character and the occurrence of intra‐formational seals.     

Controls on the organic carbon content of the lower Cambrian black shale in the southeastern margin of Upper Yangtze

Control of various factors, including mineral components, primary productivity and redox level, on the total organic carbon(TOC) in the lower Cambrian black shale from southeastern margin of Upper Yangtze(Taozichong, Longbizui and Yanbei areas) is discussed in detail in this article. Mineral components in the study strata are dominated by quartz and clay minerals. Quartz in the Niutitang Formation is mainly of biogenic origin, and the content is in positive correlation with TOC, while the content of clay minerals is negatively correlated with TOC. Primary productivity, represented by the content of Mobio(biogenic molybdenum), Babio(biogenic barium) and phosphorus, is positively correlated with TOC. The main alkanes in studied samples are nC_(18–n)C_(25), and odd–even priority values are closed to 1(0.73–1.13), which suggest the organic matter source was marine plankton. Element content ratios of U/Th and Ni/Co and compound ratio Pr/Ph indicate dysoxic–anoxic bottom water, with weak positive relative with TOC. In total, three main points can be drawn to explain the relationship between data and the factors affecting organic accumulation:(1) quartz-rich and clay-mineral-poor deep shelf–slope–basin environment was favorable for living organisms;(2) high productivity provided the material foundation for organic generation;(3) the redox conditions impact slightly on the content of organic matter under high productivity and dysoxic–anoxic condition.     

Polyoxometalate-based silica-supported ionic liquids for heterogeneous oxidative desulfurization in fuels

With the aim of deep desulfurization, silica-supported polyoxometalate-based ionic liquids were successfully prepared by a one-pot hydrothermal process and employed in heterogeneous oxidative desulfurization of various sulfur compounds. The compositions and structures of the hybrid samples were characterized by various methods such as FT-IR, XPS, Raman,UV–Vis, wide-angle XRD and N_2 adsorption–desorption. The experimental results indicated that the hybrid materials presented a high dispersion of tungsten species and excellent catalytic activity for the removal of 4,6-dimethyldibenzothiophene without any organic solvent as extractant, and the sulfur removal could reach 100.0% under mild conditions.The catalytic performance on various substrates was also investigated in detail. After cycling seven cycles, the sulfur removal of the heterogeneous system still reached 93.0%. The GC-MS analysis results demonstrated that the sulfur compound was first adsorbed by the catalyst and subsequently oxidized to its corresponding sulfone.     

环形腔扫描干涉仪及其模匹配的研究

介绍了用环形谐振腔制做而成的新型扫描干涉仪,它的设计原理是基于谐振腔之间的模匹配理论。用它来测定激光模式时不需要加隔离器。文中对于激光腔和环形谐振腔的模失配和失调问题也进行了讨论。这一装置有很好的应用前景。     

对纳米硅薄膜高电导机制的探讨

使用超高真空PECVD薄膜沉积系统制备的纳米桂薄膜（nc－Si：H）具有高电导特性。为了探讨其导电机制，先使用K．Yoshida早期提出的两相无序结构有效电导模型分别对晶粒电导和界面电导进行了理论计算。指出，nc－Si：H股中高电导主要来自于细微晶粒的传导，界面可视之为非导体。另一方面，实验证实nc－Si：H股的电导率随平均品粒尺寸减少而增大，具有明显的小尺寸效应。文中首次提出，nc－Si：H膜的微晶粒具有异质结量子点（HQD）特性，并按此模型对nc－Si：H膜的电导率实验曲线进行了讨论。理论与实验结果符合得很好．又得出，硅薄膜结构在其晶态体积百分比Xc=0．30和0．70处呈现出两个明显的相变点。     

Call admission control schemes under generalized processor sharing scheduling

Provision of Quality‐of‐Service (QoS) guarantees is an important and challenging issue in the design of integrated‐services packet networks. Call admission control is an integral part of the challenge and is closely related to other aspects of networks such as service models, scheduling disciplines, traffic characterization and QoS specification. In this paper we provide a theoretical framework within which call admission control schemes with multiple statistical QoS guarantees can be constructed for the Generalized Processor Sharing (GPS) scheduling discipline. Using this framework, we present several admission control schemes for both session‐based and class‐based service models. The theoretical framework is based on recent results in the statistical analysis of the GPS scheduling discipline and the theory of effective bandwidths. Both optimal schemes and suboptimal schemes requiring less computational effort are studied under these service models. The QoS metric considered is loss probability. This revised version was published online in June 2006 with corrections to the Cover Date.     

Traffic impacts of international roaming on mobile and personal communications with distributed data management

In this paper, we propose four network interconnection scenarios and the related signaling aspects for the international roaming traffic in mobile and personal communications. With or without international gateway relay nodes summarized from the proposed scenarios, we also derive three international roaming network sets {IR₁, IR₂, IR₃} for the observed signaling traffic model with twolevel databases. Based on the proposed performance metrics, analysis results show that under some reasonable assumptions the signaling traffic of international roaming is significantly impacted by the related gateway relay nodes and databases. In addition, the studied cache data management strategy at VLR can reduce the impacts of the signaling traffic of query operation, but the caching approach cannot improve the performance of update operation. Furthermore, the performance of proposed standalone STP scenario is better than that of integrated STP scenario for the international network connection.     

Flexible tree-structured signal expansions using time-varyingwavelet packets

Addresses the problem of finding the best time-varying filter bank tree-structured representation for a signal. The tree is allowed to vary at regular intervals, and the spacing of these changes can be arbitrarily short. The question of how to choose tree-structured representations of signals based on filter banks is considered. Wavelets and their adaptive version, known as wavelet packets, represent one approach that is popular. Wavelet packets are subband trees where the tree is chosen to match the characteristics of the signal. Variations where the tree varies over time have been proposed as the double tree and the time-frequency tree algorithms. Time-variation adds a further level of adaptivity. In all of the approaches proposed so far, the tree must be either fixed for the whole duration of the signal or fixed for its dyadic subintervals. The solution that we propose, as it allows more flexible variation, is an advance on the wavelet packet algorithm, the double tree algorithm, and the recently proposed time-frequency tree algorithm. Our solution is based on casting it in a dynamic programming (DP) setting. Focusing on compression applications, we use a Lagrangian cost of distortion +λ×rate as the objective function and explain our algorithm in detail, pointing out its relation to existing approaches to the problem. We demonstrate that the new algorithm indeed searches a larger library of representations than previously possible and that overcoming the constraint of dyadic time segmentations gives a significant improvement in practice