Theoretical Analysis of A Buoyant Jet Interacting with Small Amplitude Waves

A new theoretical solution is presented here for the dynamic characteristics of a buoyant jet due to opposing small amplitude waves.The conservation equations of mass,tangential momentum and vertical momentum are solved by the integral method which encompasses the Gaussian profiles of velocity and density.The action of waves is incorporated into the equations of motion as an external force and a new exact solution is obtained to predict the trajectory,velocity distribution and boundary thickness of the buoyant jet over an arbitrary lateral cross section.It is found that the velocity along the centerline is inversely proportional to the ratio of the momentum of the wave to the buoyant jet.The averaged boundary width varies with the fluctuation of the boundary width,the distance from the orifice and the velocity correction function.Owing to the motion d waves,the fluctuation of the boundary width is proportional to the wave steepness.     

Analyses of the long-term salinity variability in the Bohai Sea and the northern Huanghai(Yellow) Sea

Based on the comprehensive collection of the field observed salinity of the Bohai Sea (BHS) and the northern Huanghai Sea (NHS) from the 1950s to the present,the patterns of 10-years-averaged salinity at the different layers in the recent five decades (the 1950s,the 1960s,the 1970s,the 1980s and the 1990s) are obtained by the spatial-temporal interpolation technique with the scrupulous data quality control in this study.Then,by combining the spatial-temporal interpolation technique with successive correction method,the annual distributions of salinity both in the BHS and in the NHS are obtained as well.The data analyses indicate that the overall salinity in the BHS and the NHS increases from the 1960s till the present,with the increase of annual mean salinity of 0.04 psu from the 1950s,and the maximum increase rate of salinity is about 0.14 psu/a in the Bohai Bay.The high salinity tongue extended significantly from the NHS into the BHS.The intensified eastern wind field is related to the western intrusion of the NHS warm current,which probably leads to the moving forward of the high salinity water mass into the BHS.However,it is rather different from the salinity distribution characteristics between the 1950s and the 1960s.The extensive precipitation in the 1960s could lead to an increase in the discharge of the Huanghe River,which might result in the decrease of salinity in the BHS.But the salinity isoline of 32 in the NHS still extended significantly into the BHS in the 1960s.Since the 1980s,the patterns of salinity distribution have changed thoroughly.The salinity in the central area of the BHS was low,while the salinity in the Bohai Bay and the Liaodong Bay was higher than the other regions with its horizontal salinity gradient decreasing in the 1980s.The Empirical Orthogonal Function Analysis (EOF) is also conducted to study the interannual salinity variability of the BHS and the NHS.The correlation coefficient between the time coefficient series of the main mode and the Huanghe River discharge can reach -64.57%.It can be concluded that salinity variation of the BHS and the NHS has strong negative correlation with the Huanghe River discharge.     

镉和汞两种重金属离子对四角蛤蜊的急性毒性

采用毒理学实验方法,比较研究了Cd~(2+)和Hg~(2+)对四角蛤蜊(Mactra veneriformis Reeve)急性毒性效应的差异,以期为进一步评价重金属离子对四角蛤蜊的毒性效应和作用机理等提供理论依据.死亡概率单位和实验液浓度对数的线性回归分析表明,Cd~(2+)对四角蛤蜊在24、48和96 h的半致死浓度(LC_(50))分别为15.961、5.149和2.383 mg/L,Hg~(2+)的LC_(50)分别为3.714、0.607和0.207 mg/L;Cd~(2+) 和Hg~(2+) 对四角蛤蜊的安全质量浓度分别为0.023 8 mg/L和0.002 1 mg/L,分别是我国渔业水质标准(GB11607-89)限定量的4.76倍和4.02倍.     

LADCP配置文件和数据质量控制的参数设定

为在海洋调查中更好的使用LADCP获取现场观测资料和从观测资料中获取更真实的流速信息.详细阐述 了LADCP投放前配置文件和后期资料处理中数据质量控制的有关问题.给出了相关参数设置的依据,阐述了各个参数设置的不同影响,为今后外海调查提供参考.     

建设用地勘测定界信息化管理与质量控制技术方法研究

建设用地勘测定界工作作为用地审批报件的法律依据是国土资源管理工作中一项重要的技术性工作,它以农用地转用报审和土地征收报审为核心,涉及国民经济建设、国家粮食安全、农民的根本利益,对合理组织土地利用,实施土地用途管制和建设用地总量控制,保护耕地发挥着重要作用。     

如何编制好土地开发整理项目招标文件

招标文件是招标投标活动中最重要的法律文件,它不仅规定了完整的招标程序,而且还提出了各项具体的技术标准和招标条件,是投标人准备投标文件和参加投标的依据,也是评审委员会评标依据和签订施工合同的基础,招标文件编制质量好坏直接影响招标活动的成败.根据国家有关规定,2003年开始,辽宁省全面推行了土地整理项目的招标制度.随着土地整理项目招投标活动的不断深入,在招标文件编制的格式、内容、相关条款,以及标段划分、工期确定、评标办法、评标细则等方面,存在着不同程度的问题,个别项目导致合同纠纷,增加了标段间的施工协调难度,同时也影响到项目建设质量和工期.     

紧盯目标抓进度 千方百计求质量

近年来,我局按照国家、省、市的统一安排部署,高度重视,精心组织,扎实开展了第二次土地调查工作,较好完成了二次土地调查的阶段性任务。完成辖区土地调查面积734．4381平方公里,布设、测量控制点120个,测量权属界址点5000余个,签订权属界线协议书和权属界线核实证明书900余份,共布设E级GPS控制点48个,一级导线点40个,二级导线点138个,图根埋石点154个,实测界址点23268个,测绘I：500地籍图347幅,取得了权属调查相关资料、宗地草图、地籍调查表、控制测量及细部测量相关数据等成果。     

1:5万区域化探样品分析测试的质量监控

依据《地质矿产实验室测试质量管理规范》,并结合山西省的地质情况建立了一套1:5万区域化探样品分析测试的质量监控体系。分四个部分详细论述了的1:5万区域化探样品分析测试的质量监控体系。过去1:5万质量监控体系完全是靠人工进行,效率低下;本质量监控体系与过去相比,不但节省了大量的人力、物力,而且更加准确、迅速,更能适应1:5万质量监控大量数据处理的需要。     

海洋调查仪器设备在海上试验中的质量控制

阐述了海洋调查仪器设备在海上试验过程中质量控制的程序和步骤,对参加海上试验的仪器设备的试验操作和检查流程作了规范化描述,对仪器设备海上试验中出现故障及技术偏离的处理流程进行了探讨,并对试验结束后试验监督的结论和应备齐的文件记录进行了说明.为我国海洋调查仪器开展规范化海上试验及质量控制提供了依据.     

我国房地产价格的影响因素分析

房地产价格的讨论一直都是热门话题。影响我国房价的经济因素主要在于国民收入、土地价格、房地产投资和消费等方面,运用这些因素,采用模型分析方法,可以看出房地产投资是影响房价的重要原因。