长庆油田马家山东区块姬六注水系统的压力损失分析及其调整与优化

通过对姬六注水系统的压力损失分析,提出了调整与优化该系统注水压力的方法：增大姬六注至地90-90配的管道直径并适当降低水的流速,以减小系统的压力损失;减小姬六注的注水半径,为以后提高泵压留有一定的余量;新建地209-67注水撬,地209-64、208-63、209-67、209-69及213-74等由新建注水撬管辖,可以有效满足其注水需求,减小注水系统的压力损失并保证其安全、平稳、经济运行,解决了马家山东区块注水亟待解决的问题。     

青银高速济南黄河大桥46m现浇箱梁支架施工

以青银高速公路济南黄河大桥为例,详细介绍了46m连续箱梁如何采用自制门式钢支架施工,并阐述了支架的性能和工作原理。     

Reconstructed index of summer monsoon dry-wet modes in East Asia for the last millennium

Monthly precipitation datasets collected at 160 stations in China as well as the monthly winds and humidity data derived from the US National Centers for Environmental Prediction (NCEP) were used to construct the relationship between six summer dry-wet modes in eastern China and the summer monsoon airflow northward advance in East Asia. A millennial series of the monsoon dry-wet index (MDWI) was reconstructed based on Wang’s six summer dry-wet modes in eastern China since 950 AD. A high (low) index indicate...     

Study on response of ecosystem to the East Asian monsoon in eastern China using LAI data derived from remote sensing information

Based on the leaf area index (LAI) data derived from remote sensing information and eco-climate data, the responses of regional ecosystem variations in seasonal and interannual scales to the East Asian monsoon are studied. It is found that the vegetation ecosystems of eastern China are remarkably correlated with the East Asian monsoon in seasonal and interannual scales. In the seasonal timescale, the obvious variations of the vegetation ecosystems occur with the development of the East Asian monsoon from the south in the spring to the north in the autumn. In the interannual scale, high LAI appears in the strong East Asian monsoon year, whereas low LAI is related to the weak East Asian monsoon year. These further lead to the characteristic of "monsoon-driven ecosystem" in the eastern China monsoon region, which can be revealed by LAI.     

Natural interdecadal weakening of East Asian summer monsoon in the late 20th century

Based on the reanalysis data throughout 1948-2002 as derived from the United States National Centers for Environmental Prediction and National Center for Atmospheric Research, it is revealed that East Asian summer monsoon （EASM） intensity weakens on an interdecadal timescale since the mid-1960s, and twice interdecadal jumps are recorded in the EASM intensity index series in the late 20th century, respectively occurring in the mid-1960s and mid- to late 1970s. Six globally coupled atmosphere-ocean models＇ outputs under the SRES A2 greenhouse gas and aerosol emission scenario, provided by the IPCC Data Distribution Center and the Hadley Center for Climate Prediction and Research, are then systematically examined. It follows that the above EASM weakening is not closely related to synchro- nizing anthropogenic global warming, and, therefore, it should be qualitatively natural change process. Over the 21st century, the EASM intensity is likely increased slightly by continually intensified greenhouse effect relative to the late 20th century.     

建设和谐与繁荣新平台的首届东亚峰会

首届东亚峰会的召开,为东亚区域合作搭建了一个新平台。这次历史性会议,是东亚合作进程中的一件大事,标志着东亚合作进入一个新的发展阶段。在经济全球化和区域合作步伐不断深入发展的背景下,东亚峰会担负着探讨和促进本地区各国相互依存、共同发展和繁荣的艰巨任务。尽管前进道路不平坦,但只要共同努力,就能不断谱写本地区和平、稳定、发展与繁荣的新篇章。     

A high-resolution stalagmite O-C isotope record from Nanjing and its rapid response to climatic events

Here we discussed rapid response of the cave temperature and vegetation to the four Dansgaard-Oeschger cold and warm cycles during 50-40 kaBP based on results of oxygen and carbon stable isotopic compositions from a stalagmite in Tangshan, Nanjing. It is found that the amount of C₃ vegetation relative to C₄-type declines during the D-O warm events, indicating the decrease of the effective meteoric precipitation. Compared with O-isotope records of the Greenland ice core, the stalagmite record displays a very similar pattern to Greenland ice core record over the decade-century time scale, suggesting that the changes of the East Asian monsoon climate are in accordance with the high-latitude polar climate in the short-term time scale. The age of the ice-rafted H5 event in the stalagmite record, however, preceded that of Greenland ice cores by 2 ka. This out of phase between the remote areas cannot be yet proven because the two time scales were determined from different dating methods.     

潮汕平原晚第四纪沉积相与古环境演变

通过潮汕平原第四系一些钻孔的沉积相，孢粉学及＾１４Ｃ年代分析，论述了韩江，榕江及练江三角洲的古环境演变，认为有过两次以上的海侵期，而主要的三角洲韩江三角洲的发育可分为前三角洲期，古三角洲期和现代三角洲期，这些古环境的演化与南海的δ＾１８Ｏ曲线相对应。     

北京方庄地下古船的发现及其埋藏环境的研究

方在古船是北京地区发现的第一般古船实物，船板的￣（１４）Ｃ年代为距今２２０５±７０年，埋藏地层中树木的￣（１４）Ｃ年代为距今１７３７±８６年。通过对船址所在地区的调查、地层剖面的详细观察测量和对沉积物样品的分析，结合历史文献的考证，认为方在古船址区是东汉时期古高梁河的流经之地。沉积特征表明该河河型为弯曲型河流。以后由于气候变干，加之上游人工改造和河道东移，导致该河流从本区消失。方庄古船的发现首次证实了东汉时期古高梁河向城南流出的确切位置，为永定河全新世的演化提供了新的证据。     

东海带鱼资源现状及管理对策

本文对１９８０年以来东海带鱼的资源状况和变动原因作了分析。结果表明，资源基础以八十年代中期最为薄弱，近几年的带鱼资源数量已增加到八十年代初的水平。但资源量的增加部分均为低龄鱼和幼体，高龄鱼比例反而下降。目前带鱼低龄化、小型化现象明显，资源尚处于生长型过度捕捞中，渔获量的上升并非资源的根本好转。影响带鱼资源恢复的主要原因是捕捞强度过大和不合理利用资源。针对资源现状，文章提出了“夏保、秋养、冬捕”的管理意见，在近期可先增加实施夏秋季底拖网局部或全海区休渔２－３个月的管理措施，以减轻捕涝压力，逐渐使资源恢复到正常水平。