套铣捞取小直径桥塞的研制与应用

为了解决因套管损坏产生的老井报废停产问题,用101.6mm(4英寸)套管作为报废的139.7mm(512英寸)套管井更新改造的主要措施在各油田大量应用。针对液流较大的井填砂或打水泥塞均难以完成下部层段暂堵工艺的问题,研制了套铣捞取小直径桥塞,并为之配套了相应的油管液压投送工艺工具及后期处理工具。该工具能够用于101.6mm套管井措施工艺管柱中,解决了101.6mm套管井下部层段高压堵水、低压堵漏的技术难题。同时可用于压裂、酸化、挤堵、调剖等措施管柱中,以满足施工对下部层段暂堵保护的要求。现场应用情况表明,该工具下井试验应用21口井,均一次成功,密封效果良好。

Determination of isolation layer thickness for undersea mine based on differential cubature solution to irregular Mindlin plate

The differential cubature solution to the problem of a Mindlin plate lying on the Winkler foundation with two simply supported edges and two clamped edges was derived.Discrete numerical technology and shape functions were used to ensure that the solution is suitable to irregular shaped plates.Then,the mechanical model and the solution were employed to model the protection layer that isolates the mining stopes from sea water in Sanshandao gold mine,which is the first subsea mine of China.Furthermore,thickness optimizations for the protection layers above each stope were conducted based on the maximum principle stress criterion,and the linear relations between the best protection layer thickness and the stope area under different safety factors were regressed to guide the isolation design.The method presented in this work provides a practical way to quickly design the isolation layer thickness in subsea mining.

Seasonal variation in species composition and abundance of demersal fish and invertebrates in a Seagrass Natural Reserve on the eastern coast of the Shandong Peninsula,China

Seagrass habitats are structurally complex ecosystems, which support high productivity and biodiversity. In temperate systems the density of seagrass may change seasonally, and this may influence the associated fish and invertebrate community. Little is known about the role of seagrass beds as possible nursery areas for fish and invertebrates in China. To study the functioning of a seagrass habitat in northern China, demersal fish and invertebrates were collected monthly using traps, from February 2009 to January 2010. The density, leaf length and biomass of the dominant seagrass Zostera marina and water temperature were also measured. The study was conducted in a Seagrass Natural Reserve(SNR) on the eastern coast of the Shandong Peninsula, China. A total of 22 fish species and five invertebrate species were recorded over the year. The dominant fish species were Synechogobius ommaturus, Sebastes schlegelii, Pholis fangi, Pagrus major and Hexagrammos otakii and these species accounted for 87% of the total number of fish. The dominant invertebrate species were Charybdis japonica and Octopus variabilis and these accounted for 98% of the total abundance of invertebrates. There was high temporal variation in species composition and abundance. The peak number of fish species occurred in August–October 2009, while the number of individual fish and biomass was highest during November 2009. Invertebrate numbers and biomass was highest in March, April, July and September 2009. Temporal changes in species abundance of fishes and invertebrates corresponded with changes in the shoot density and leaf length of the seagrass, Zostera marina.

论地方立法的公众参与和人权保障

地方立法是指省一级地方权力机关或者行政机关所制定或者发布的地方法规规章,社会民主最主要的实现方式就是立法民主,而地方立法更是其实现立法民主的主渠道。地方立法的特定性使得地方立法民主一方面具有合理性、必要性,而且具有可行性,故设置地方立法的民主程序,吸收最广泛的公众意见和程序参与,体现立法对民权和人权的关注和保障,尤其是底层关注和弱者保护更应当是地方立法突出的主题。