反渗透抗污染膜在污水回用上的工艺研究

利用城市污水处理厂达标排放水为源水,经过生化塔-两级过滤-反渗透系统处理后,产水水质达到了电厂循环冷却水的水质标准,成功的取代了自来水.VONTRON公司的抗污染反渗透膜FR11-8040在系统中经过两年的运行表现出很好的稳定性,系统的回收率总体保持在70%左右,系统脱盐率在99%左右.     

2 500 TEU集装箱船的总体设计

随着人们对环境保护的日益重视,越来越多的法规对船舶设计提出更高的环保要求.通过2 500 TEU集装箱船的总体设计,对装载和破舱稳性等总体性能等进行了设计计算,使该船布置合理紧凑,各项指标达到国际先进水平.但燃油舱划分和分布要满足有关新规划,还需作适当调整.     

Intelligent VIV control of 2DOF sprung cylinder in laminar shear-thinning and shear-thickening cross-flow based on self-tuning fuzzy PID algorithm

A self-tuning fuzzy PID (ST-FPID) control scheme is implemented within a joint interactive (Matlab/Simulink/Fluent) co-simulation framework for effective two degrees of freedom (2DOF) vortex-induced vibration (VIV) control of an elastically-mounted circular cylinder in laminar cross-flow of incompressible non-Newtonian power-law fluids based on the control action of a single transverse force actuator. The model-free controller, which systematically tunes the control parameters online in real time based on given rules, is well-known to be highly advantageous over the previously employed conventional PID controllers. It is particularly capable of handling the intricate non-linear dynamic effects inherent in the complex fluid rheology of non-Newtonian flow past the cylinder in presence of unmodeled system dynamics, high parametric uncertainties, diverse operational conditions, and time-varying external disturbances and control signals. Extensive numerical simulations reveal that the complex shear-thinning and shear-thickening behaviors of fluid viscosity can substantially influence the cylinder dynamic response, applied hydrodynamic forces, and flow structure. In particular, effectiveness and high performance of the adopted ST-FPID control strategy in substantial suppression of the high amplitude coupled 2DOF VIV of the elastically-mounted cylinder at selected critical reduced velocities in the lock-in region are established for a wide range of power-law index parameters (e.g., up to 83% reduction in RMS value of cylinder cross-flow displacement and up to 35% reduction in RMS value of cylinder in-line displacement for n=1and U* = 5 at Re = 100). Also, the vigorous action of the error-driven ST-FPID controller in forcing the high strength vortex shedding patterns of the uncontrolled cylinder out of the lock-in condition into the classical von Kármán vortex street of 2S-type mode of moderately weaker strengths is verified.     

动态变形模量E_(vd)标准的应用与展望

系统介绍国外高速铁路路基压实标准和检测手段的发展历程 ,阐明动态变形模量Evd 标准已成为高速铁路路基压实标准的发展趋势 ,论证高速铁路路基工程质量控制标准采用Evd 的必要性及可行性。     

水资源调度工程对城市内河水环境改善的作用分析

为科学、客观地反映调水引流工程在解决城市地区水环境问题中发挥的作用,需建立一维水质模型。该文以南宁市环相思湖水系调水工程为例,通过分析计算表明连续调水对环相思湖水环境有较大改善作用。     

上海轨道交通11号线南段地铁隧道中隔墙施工技术

上海轨道交通11号线南段工程在国内首次采用1158 m泥水平衡盾构施工,并运用钢筋混凝土墙板结构分隔单圆空间,形成单管双线地铁隧道。结合施工进度要求和现场环境条件,首创特制机械拼装预制中隔墙技术,可大幅度提高施工效率和工程质量。文章就中隔墙施工关键技术（如预制件吊装施工技术、预制中隔墙安装临时支撑技术、预制件顶部传力杆安装技术）进行阐述。     

IEEE802.11n中的STBC-OFDM系统方案性能分析

推导出IEEE802.11n中STBC-OFDM系统方案的最小距离球界的平均符号差错概率计算公式,通过研究分析,该系统方案可获得最大的分集增益nTnRL,即发射天线数、接收天线数和多径总数的乘积。     

UR-S11A对大型集装箱船结构设计的影响研究

国际船级社协会针对集装箱船的新标准UR-S11A已于2016年7月1日正式生效,其对大型集装箱船结构设计的具体影响值得研究。以一艘13 500 TEU集装箱船为例,首先分析了UR-S11A相比UR-S11和劳氏船级社(LR)规范在强度校核上的差异,然后通过对总纵屈服强度、屈曲强度和极限强度的研究分析了新标准对船体结构的影响。结果表明,UR-S11A对在0.3~0.4船长处船体梁的总纵弯曲和极限强度的要求更高,部分纵舱壁板与外板的剪切和屈曲强度以及双层底桁材纵骨的屈曲强度受新规范影响较大。     

A study of the response of chlorophyll-a biomass to a winter upwelling event off Western Iberia using SeaWiFS and in situ data

Observations of a winter upwelling event off Western Iberia shelf/slope in the area of influence of the Western Iberia Buoyant Plume (WIBP) were conducted in February 2000. Spatial patterns and time evolution of the chlorophyll-a (chl-a) biomass are analysed, based on in situ and satellite data. SeaWiFS-derived chl-a concentration L2 products were used to track the chlorophyll front and estimate its westward migration velocity (maximum up to 29 km day⁻¹), as well as to characterize the frontal system and its evolution. A method associating the type of spectral signature of a pixel to the fraction of chlorophyll probed by SeaWiFS enabled the estimation of the chl-a biomass within error intervals. High chlorophyll concentrations (for wintertime) were observed over the shelf and slope, up to large distances to the coast. Due to the WIBP, a shallow Ekman layer developed, being nearly coincident with the stratified upper meters. The transport comprised westward advection and stretching of the plume, with little entrainment with the offshore deep mixed layer waters. The relative enlargement of the total area of the Inside-Front Zone (IFZ) during the upwelling event was roughly accompanied by the maintenance of the average biomass per unit of area, considering the water column up to depths of interest. This suggests that there was a net increase of chl-a biomass inside the water column associated with the IFZ, roughly proportional to the increase in the IFZ area. Retention of phytoplankton in the shallow stratified nutrient-rich waters of the WIBP was a key factor for this increase in chl-a biomass.     

区间序列计数

利用递归,对称等多种方法研究了[1,n]上l度k-区间序列的计数问题,给出了计数公式。特别当k=2,3时,通过分析SIV结构表,得到了s（n,k,l）简洁的多项式计数公式。