条码技术在集装箱生产企业卷钢管理中的应用

<正>条码技术发端于20世纪40年代,经过近30年的发展,至20世纪70年代逐渐成熟,与磁条技术、智能卡技术、光字符识别技术、系统集成化技术、射频技术、语音识别技术及视觉识别技术等共同组成以计算机、光学、机械、电子、通信为一体的自动识别技术体系。[1]我国条码技术起步较晚,但发展迅速。     

技术成熟度评价方法在导弹武器系统中的应用

为了有效降低装备研制中的技术风险,技术成熟度评估一直是装备采办中令人关注的问题。简要介绍了国外技术成熟度评价方法,技术成熟度等级的划分,并以虚拟的导弹各分系统技术验证项目为例进行了技术成熟度模拟评价,运用层次分析法求得技术成熟度等级。     

论缩微技术与数字技术的结合

在科学技术飞速发展的今天,数字文献信息以前所未有的速度和数量被源源不断地生产出来。缩微技术受到了以计算机为核心的光盘、磁盘等多媒体技术的冲击,致使缩微技术的发展明显放慢。在文献信息管理中,数字技术、缩微技术各有所长,缩微技术不会被数字技术所取代,相反两种技术不断融合、模拟与数字技术混合系统共存将成为文献信息管理的发展主流。     

潜艇作战分析模拟系统的设计与实现

本文介绍了一个用于潜艇作战分析研究系统的结构、技术设计和实现方法,在该系统中采用了新的技术,包括人工智能技术、模型库技术、状态程序设计技术、多窗口用户界面技术、网络互连技术、多媒体技术等。本文重点介绍该系统硬软件平台的构成及专家系统技术在该系统中的应用。     

基于SBD技术的船舶水动力结构云平台架构研究

近年来,最优化技术不断发展,该技术已经逐渐应用于船舶设计领域,同时,结合先进的CFD技术,发展形成SBD技术。该技术为船舶水动力结构的设计和优化开创了新的局面,已经成为船舶设计领域的研究重点。本文以SBD技术为基础,重点研究了最优化技术和云计算海量数据处理技术,提出了改进的PSO优化算法。     

船用双燃料低速柴油机节能减排部分关键技术

双燃料低速柴油机在保持原发动机高效率的同时,能够大幅减少污染物排放。为了进一步缩小国内双燃料技术与国外技术的差距,文章从燃气进气技术、气体喷射技术以及燃烧技术3方面,对Laby-GI气体压缩机、泵气化单元、先导喷油器、双针阀喷油器、预混合稀薄燃烧技术、狄塞尔循环燃烧技术等船用双燃料低速柴油机技术进行分析,总结以上技术在节能减排方面的优势,为我国在双燃料低速机领域的技术发展提供理论支撑。     

灵境技术及其在系统仿真中的应用

灵境技术是多媒体技术的结晶,也是人机接口技术的最后堡垒。本文从灵境技术的定义与特点出发,论述了建造灵境的基本原则和它的技术基础。通过灵境应用示例,展示出其诱人的发展前景。最后,分析了系统仿真对灵境技术的需求,并探讨了灵境技术在系统仿真中的应用。     

舰艇惯性导航技术现状及发展趋势

讲述了国内外海军舰艇用惯性导航技术的现状,分析并预测了发展趋势。简述了舰艇用惯性导航技术的技术特点和使用需求特点,从惯性敏感器技术和系统技术两个方面对惯性导航系统产品进行了分类。通过阐述技术特点与不同使用需求之间的对应关系,探寻技术发展方向;并以国内外舰艇惯性导航技术发展的历程进行佐证。     

美国核潜艇推进系统减振降噪技术发展分析

简要介绍潜艇中的噪声源,从推进器技术、浮筏减振技术、自然循环压水堆技术和电力推进技术4个方面对美国核潜艇推进系统减振降噪技术进行梳理,得到减振降噪技术发展历程,并从中得到有益启示。     

COM技术的利与弊

分布式对象技术是当今技术发展的趋势 ,作为分布式对象技术的主流技术之一 ,微软的组件对象模型COM具有极强的技术优势和竞争力。以COM为主要研究对象 ,重点阐述了COM的技术优势与局限性     

潜艇超空泡技术应用分析

结合目前国内外超空泡技术的发展,论述发展超空泡潜艇的必要性,介绍了超空泡技术基本原理。依据超空泡鱼雷的配置,提出“变形空化器”的概念;论证超空泡潜艇推进和控制系统的选择;分析导引设备和尾舵的作用以及可能出现的问题。结合4种超空泡航行体稳定模式,分析超空泡潜艇水下稳定性问题,提出超空泡潜艇发展设想。结合对潜艇操纵研究,分析超空泡潜艇的水动力特性问题。同时,对 Suboff潜艇模型进行了流场特性的仿真计算,结果表明：潜艇的头部、指挥室的迎风面、指挥室的两侧艇体和潜艇的尾翼均存在一定的沾湿区域。基于此结果,提出相应的改进方案。对超空泡潜艇未来主要工作进行展望。     

台风条件下TLP串行立管系统碰撞分析

TLP立管系统以丛式方阵排列,台风条件下立管在波浪、海流及平台的联合作用下可能发生碰撞,有必要深入研究TLP串行立管系统的碰撞情况。文章基于DNV-RP-F203规范和Huse半经验尾流模型,提出台风条件下串行立管下游立管来流速度计算方法和立管系统碰撞分析方法,建立串行立管—井口—导管系统耦合有限元模型,研究台风条件下串行生产立管系统碰撞时的力学特性,在整体碰撞分析的基础上进行立管局部碰撞精细化分析,对比分析立管局部碰撞理论解和仿真解的不同。结果表明:下游立管来流速度的计算至少采用文中建立的方法迭代3次。串行立管发生碰撞时的最大应力发生在泥面导管处,碰撞位置应力发生了突变;立管发生碰撞的位置在水深100-120 m范围内。立管局部碰撞分析的理论解和仿真解基本吻合。     

攻角空化器的超空泡形态非对称特性研究

为了满足水下高速超空化航行体运动平衡性和稳定性要求,必须采用非对称超空泡流动模式,采用具有非零攻角的空化器是实现该要求的一种重要策略.基于冲量定理,理论分析了非零攻角空化器引起的超空泡轴向变形量随轴向长度的关系,获得了空化器攻角对超空泡非对称性及其影响因素之间的定性和定量关系,其一阶近似与同类文献的结论是一致的,数值模拟表明了所得结论的合理性和分析的正确性.研究表明,非零攻角空化器引起的超空泡轴线变形量与沿空泡长度的距离呈线性规律增加,并在空泡尾部达到最大,不可能单独利用空化器攻角沿空泡长度来中和重力影响.     

Wind-triggered events of phytoplankton downward flux in the Northeast Water Polynya

Phytoplankton carbon fluxes were studied in the Northeast Water (NEW) Polynya, off the eastern coast of Greenland (79° to 81°N, 6° to 17°W), during summer 1993. The downward flux of organic particles was determined during 54 days using a sediment trap moored at a fixed location, below the pycnocline (130 m). The hypothesis of the present study is that wind events were ultimately responsible for the events of diatoms downward flux recorded in the trap.Wind conditions can influence the vertical transport of phytoplankton by affecting (1) the environmental conditions (e.g. hydrostatic pressure, nutrient concentrations, and irradiance) encountered by phytoplankton during their vertical excursion, and (2) the aggregation and disaggregation of phytoplankton flocs. The first mechanism affects the physiological regulation of buoyancy, whereas the second one affects the size and shape of settling particles.Using field data (wind velocity, density profiles and phytoplankton abundance), we assessed the potential aggregation and the vertical excursion of phytoplankton in surface waters. The results show that, upstream from the trap, wind and hydrodynamic conditions were sometimes favourable to the downward export of phytoplankton. Lag-correlation between time series of wind and phytoplankton downward flux shows that flux events lagged wind events by ca. 16 days. Given that the average current velocity in the top 100 m was ca. 10 cm s⁻¹, a lag of 16 days corresponded to a lateral transport of ca. 130 km, upstream from the sediment trap, where phytoplankton production was lower than at the location of the trap. According to that scenario, 21% to 60% of primary production was exported to depth during wind events. If we had assumed instead a tight spatial coupling between the material collected in the trap and the relatively high phytoplankton production at the location of the trap, we would have concluded that <7% of primary production was exported to depth. The difference between the two scenarios has great implications for the fate of phytoplankton. Our results stress the importance of investigating the spatial coupling between surface and trap data before assessing the pathways of phytoplankton carbon cycling.     

Use of SeaWiFS data for light availability and parameter estimation of a phytoplankton production model of the Bay of Biscay

Processing SeaWiFS (Sea-viewing Wide Field-of-view Sensor) data provides useful information for the observation and modelling of the phytoplankton production of the Bay of Biscay. Empirical algorithms allow the retrieval of chlorophyll a and non-living Suspended Particulate Matter (SPM) concentrations. These data are used to constrain a coupled 3D physical–biogeochemical model of the Bay of Biscay continental shelf. Two issues are investigated, depending on the variable used, to constrain the winter to spring phytoplankton production for the year 2001. First, SPM data is used as forcing data to correct the corresponding state variable of our model. This allows the realistic simulation of the light limited bloom at the end of February 2001, as observed with SeaWiFS chlorophyll a images and from the NUTRIGAS field cruise. Second, chlorophyll a data is used for parameter estimation of the biogeochemical model. The ability of assimilating these data is tested to improve the simulation of strong blooms observed in late May 2001 in the Loire and Gironde plumes. A global optimization method (Evolutive Strategies) is adapted to the complete 3-D coupled model, in order to find the best set of parameters. The hydrological conditions during the bloom can be validated with data from the PEL01 field cruise. After selection of the most sensitive parameters, the method is tested with twin experiments. Then, the use of real SeaWiFS data reduces the model/data misfit by a factor of two, improving the simulation of bloom intensities and extensions. The sets of parameters retrieved in each plume are discussed.     

钢-混凝土箱型组合斜拉桥主梁混凝土收缩徐变分析

组合梁斜拉桥兼有混凝土和钢结构的优点,但作为两种材料的结合体,混凝土收缩徐变会引起组合截面的应力重分配,可能促使混凝土裂缝的提前出现或加速裂缝的扩展,从而降低结构的受力性能和耐久性。采用有限元方法分析了混凝土收缩徐变对组合梁斜拉桥主梁应力重分布的影响,并对混凝土的加载龄期的影响进行了参数分析。计算结果表明：混凝土加载龄期越早,组合截面的应力重分布越明显;混凝土收缩徐变对混凝土桥面板的应力影响不大,但对钢梁应力影响较为显著,钢梁的应力增量达到钢材容许应力的30%左右。     

Mechanical model and characteristics of deep-water drilling riser-wellhead system under internal solitary waves

Internal solitary waves with a huge amount of energy easily trigger the large dynamic responses of riser-wellhead system and threaten its structural safety. However, previous studies have only focused on the dynamic response of the riser under internal solitary waves. The riser may experience excessive traction from the platform, especially from the mooring platform, in response to the arrival of internal solitary waves. The bottom of the riser connects to the wellhead system, which in turn exerts a reaction force on the riser. To address this problem, a coupled dynamic model of deep-water drilling mooring platform-riser-wellhead system under internal solitary waves is developed in this paper. A dynamic response analysis method based on the fourth-order Runge-Kutta method and finite element method is also proposed for the mooring platform-riser-wellhead system. A dynamical solver for the coupled system is then developed using MATLAB. The dynamic response characteristics of the riser-wellhead system under internal solitary waves are calculated. Results show that the displacement and bending moment of the system initially increases and then decreases along with the propagation of internal solitary waves, and finally reach equilibrium position. The displacement and bending moment reach their peak before the trough of internal solitary waves passes through the riser-wellhead system. The dynamic responses of the riser-wellhead system under the influence of internal solitary wave loads are much larger than those without the effect of internal solitary wave loads. The riser system experiences shearing loads at the interface of internal solitary waves, which trigger a step-like bending moment variation. The bending moment of the conductor under the mudline is greatly increased by the internal solitary waves.     

土工格栅加固港区道路基层效果分析

我国华南港区,高温多雨,因荷载轮压很大造成路面不同程度的破坏。港区道路基层强度承载能力决定港区道路使用性能。考虑港区深软土地基,基于塑性理论,运用有限元软件模拟分析土工格栅加固港区道路基层效果。分析研究表明,采用有限元方法模拟土工格栅加固港区基层的结果与试验段结果相对应;弯沉与极限荷载成反比关系,弯沉值小,极限荷载大,表明土工格栅能提高港区基层结构承载能力,并且,土工格栅放置位置越接近面层,加固效果越好。     

USB同步传输在实时数据采集中的应用

讨论了基于USB接口的同步多路数据采集系统的设计。采用单片机控制数据实时采样，在主机WDM驱动程序设计中利用链表技术增加IRP(I／0Request Packet)USB总线驱动程序提交URB(USB Request Block)的数量，改善了采样数据的完整性，使整个采集系统的实时性能有所提高。     

Recent progress on wave induced loading measurements in warships

Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.