荒漠绿洲PRED系统特征与可持续发展定量研究

荒漠绿洲PRED系统是一个相当脆弱的系统，自然灾害频繁、水分失衡导致的生态风险大。在分析其特征的基础上，建立了衡量可持续发展的指标体系并运用层次分析法得出了这些因子对绿洲PRED系统可持续发展的权值，影响最大的前三位因子是：人均水资源量、绿洲化面积、人口素质、其权值分别为0.124、0.077、0.062。计算了河西走廊20个县（市、区）的SDI，排在最前面的依次是：萧北蒙古族自治县、嘉峪关市和玉门市、金川区，其SDI分别为0.437、0.406、0.405，排在最后面的依次是：古浪县、民勤县、天祝藏族自治县，其SDI分别为0.150、0.213、0.217。分析了这种格局产生的原因并提出了相应对策。     

城市化进程中的战略环境评价(SEA)初探

城市化是中国现代化进程中面临的一个重要问题。21世纪初期，中国城市化发展将进入快速发展的关键时期，开展城市化进程中的SEA，即在城市化决策的各个层次前瞻性地考虑政策、规划、计划及其替代方案的环境影响，有助于提高决策质量和实施可持续发展。文章对城市化进程中SEA的概念、对象、评价目标、评估指标体系和评价方法进行了初步探讨，并提出城市化进程中SEA的基本程序。     

Numerical Study of Oil Pollution on Sea Waters

This paper adopted an upstream FEM of 2-D unsteady flow to calculate the tidal flow in Zhoushan sea area. Based on the verification of the tidal current and environmental situation, the effects of the oily waste discharged from the oil berths on water quality have been calculated with a similar method. The isodilutions of oil pollutant are drawn from different sewage discharges. The moving loci of the slick centrepoint of oil spill have been calculated. The spreading area of the oil spill has also been forecasted. The results indicate that the set of models can predict the transport of oil spill in the sea area with reasonable accuracy.     

重金属对波部东风螺早期发育的毒性及EDTA的解毒效果

研究了重金属Cu2 、Zn2 、Cd2 、Pb2 对波部东风螺(Babyloniaformosaehabei)胚胎和面盘幼体的毒性效应及EDTA对幼体Cu2 、Zn2 中毒的解毒效果。结果表明,Cu2 、Zn2 、Cd2 、Pb2 在胚胎发育中最高允许浓度分别为0.01、0.05、0.10、0.50mg·L-1;对幼体的48hLC50值分别为33.251、86.352、1524.191、4751.042μg·L-1,96hLC50值分别为21.772、59.418、1072.182、3031.019μg·L-1;安全浓度分别为2.177、5.942、107.218、303.102μg·L-1;4种重金属离子对胚胎和幼体的毒性顺序均为:Cu2 >Zn2 >Cd2 >Pb2 。Cu2 、Zn2 浓度分别为0.2、0.5mg·L-1时,EDTA对面盘幼体的最佳解毒浓度分别为1—2和2—3mg·L-1。     

Case studies of ERS-1 altimeter data applicating in China Sea

1 IwrRODUcrIONAn initial field of wave height in a computing domain is needed fOr integration ofnumerical wave model. Because real time. observation ocean data are scarce, now most ofinitial fields of ocean wave is produced by either reckoning wind fields or preceding 24hour prediction results. It is possible to form an initiaI field of ocean wave along with the..increasing satellite data, ship report and buoy data. Some of research works have beendone abroad (Janssen et a1, l989; LionelI…     

Free Vibration of Sagging Pipelines in Water

- Studied in this paper is free vibration of a long span pipeline with nonlinearities taken into account. The pipeline sags under gravity and takes the shape of a plane curve. Vibration in the plane and out of the plane is regarded as small motions about the large static deflection. Manifestations of nonlinearities such as amplitude-dependent frequencies and internal resonance are investigated.     

Effect of Distortion Ratio on Local Scour Under Tidal Currents and Waves

Five generalized physical models of drfferent distortion ratios were bruit according to DOU Guo-ren‘s similarity theory of total sediment transport modeling for estuarine and coastal regions. Experiments on local scour in front of groins were made under the actions of tidal currents and waves with clear and sediment entraining water. The scour depths under different dynamic actions are compared. The effect of the distortion ratio on the depth of scour hole is discussed. A relationship between scour depths for distorted and undistorted models is given.     

Recovery Behavior of the Propagating Buckle on Elastic Structures

Based on the beam system model used by Chater, Hutchinson and Neale (1982), the recovery behavior of propagating buckle on elastic structures is first found out from the computational results. As the representative of some elastic structures, the Chater-Hutchinson-Neale model indicates that once the buckle meets arresters, unlike the case in submarine pipelines, it will be reflected back to continue its propagation in a negative phase or a negative direction. The pressure which maintains the negative propagation, however, is as same as that required for the positive propagation. This fact has been examined in the experiment of the bulge propagation on a long elastic latex tube. The present discovery greatly supports the hypothesis that the buckle propagation coresponds to the coexisting phase of structures.     

Numerical Solution of Membrane Forces for A Free-Free Floating Plate with Large Deflection

1 .IntroductionVerylargefloatingstructures (VLFS)haveattractedconsiderableattentionrecentlyduetoitspo tentialuseintheexploitationofoceanresourcesandintheutilizationofoceanspaces (Cui,2 0 0 2 ) .Owingtoitslargesizeandrelativelysmallthickness ,theinfluenceofelasticdeformationonthehydro dynamicresponseisimportant.Thisisknownashydroelasticity .Threedimensionallinear (Wu ,1 984;PriceandWu ,1 985)andnonlinear (Chenetal.,2 0 0 3)hydroelasticityiswellappliedtotheanalysisofthreedimensionalshipsando…     

以合成雪硅钙石为晶种回收废水中的磷

以合成雪硅钙石为晶种,探索了用结晶法以磷酸钙形式回收废水中磷的适宜条件。结果表明,在实验水质条件下,模拟废水pH=8、n(Ca)/n(P)=2、晶种用量大于1.6g/L、振荡24h后溶液中残留磷可达到国家污水综合排放标准一级(0.5mg/L)以下;在优化条件下证实了合成雪硅钙石的供碱能力,循环利用18次,回收磷的效果仍然很好。运用XRD、FTIR、SEM和EDS等测试手段对在实验条件下重复使用18次的雪硅钙石进行了表征,证明回收的磷主要以结晶度不高的羟基磷灰石形态存在。