K-rich lamellar exsolution in clinopyroxene： Constraint on the depth of peridotite source at Zhimafang

The oriented lamellar K-rich exsolutions within clinopyroxene host were recognized in garnet peridotite massif at Zhimafang in the Sulu ultrahigh pressure metamorphic terrane, eastern China. EMP and TEM analyses revealed that the composition and the index of electron diffraction for this exsolution are corresponding with phlogopite, and the shape is the lamellae with 1 μm in width and 5 to 30 μm in length. Moreover, the topotaxy is that the (001) of K-rich exsolution parallels to (I00) of the clinopyroxene host. The electron diffraction analyzing shows the exsolution is of a 1M polymorphism. The high-resolution lattice fringe image displays the stack features along [001], which only a layer mineral shows. We conclude that the clinopyroxene with IM and K-rich exsolution was probably derived from mantle depths over 240 km, thus resulting from decompressional exsolution in the initial stage of slab exhumation.     

板块运动的纬向重力模式

按照“纬向正常密度假说”的观点提出了“纬向密度异常”和“纬向重力”的概念,进而提出了板块运动的“纬向重力模式”,按照这一模式,纬向重力总是把地球物质从“纬向密度异常高”的地区推向、纬向密度异常低！”的地区,一方面,,纬向重力驱动岩石圈沿水平方向运动,另一方面,因纬向重力驱动软流圈物质沿水平方向运动而使得岩石圈沿垂直方向发生,同密度异常高地区的岩石圈会因软流圈物质的流失而下沉,纬向密度异常低地区的岩石圈会因为软流圈物质的补充而上升。     

A weak El Nio event in 2002 detected by the astronomical observation

Using the length-of-day (LOD) data series derived from astronomical observations made by various modern space techniques, southern oscillation index (SOI) and anomalies of sea surface temperature (SST) in tropical Pacific Ocean, the inter-annual components of these data series are obtained by the technique of band filtering from January 1962 to October 2002. It is found that a new ENSO event has already occurred in 2002 and been detected by the interannual LOD. It is shown by the wavelet analysis that the component with a period of about 4-6 years and the quasi-biennial component are out of phase during 2001-2002, which consequently suggests that the new ENSO event cannot be a strong one.     

2007：“厄尔尼诺”＋全球变暖=史上最热？

2006年下半年，世界气象组织发出警告，“厄尔尼诺”现象已在太平洋赤道海域形成，它将于2007年前4个月在地球广大地区，包括从美国到东南亚再到非洲之用，引发极端天气气候事件。据此，一些英美气象学家警告说，     

世界难题：天路冻土

地质史神话般地为我们描绘了一个不可思议的沧海变桑田的事实:很久很久以前,现今青藏高原还是一片海洋,叫做“特提斯海”。慢慢地,从遥远的南边漂来一块大陆——“冈瓦纳古大陆”,与欧亚板块相撞,成就了“喜马拉雅造山运动”——地质史上最重大的事件之一。从此,就像美女头顶盘起的发髻,地球上隆起了这么一块最高的地方。在地球上最高的地方修建铁路,人们面临的最大技术难题是:它将穿越绵延数百千米的难以对付的多年冻土。     

《普通植物病理学》分段式板块化教学模式探索

本文简述了《普通植物病理学》课程教学中如何实施板块式教学模式以及在理论授课中尝试分段式教学的过程。通过基础理论学习、因材施教个性化发展和研究性学习,激发学习兴趣、提高科研素质,增强综合能力。     

对口高考《电工技术基础》复习方法初探

本文针对职高《电工技术基础》知识的复习教学,从四个方面列举,就如何进行深入分析、探索挖掘,归纳出便于掌握知识的思路、方法、规律、技巧等作了探讨.     

西北太平洋浮游有孔虫的SSU rDNA序列及其古海洋学意义

研究对采集于西北太平洋冲绳海槽表层水体中的活浮游有孔虫进行DNA分析尝试，获得了西北太平洋浮游有孔虫Pulleniatina obliquiloculata 和Globigerina sp.等的SSU rDNA序列特征，并与南太平洋地区属种的DNA序列进行对比. 结果显示两不同海区P.obliquiloculata个体的SSU rDNA差异与同一个体内不同拷贝序列间差异类似，仅为0.7%—1.2%. 详细比较研究认为，传统微体古生物形态学定义种对西北太平洋与南太平洋的P.obliquiloculata来说具有可靠的分子生物学证据.     

^226Ra evidence for the ecosystem shift over the past 40 years in the North Pacific Subtropical Gyre

Surface seawater was collected for ~(226)Ra measurement in the North Pacific Subtropical Gyre from July to October, 1999 and October to December, 2003. Combined with the historical data reported for this sea area, a declined trend of surface ~(226)Ra concentrations was observed since 1960s, indicating the ecosystem shift in response to global warming. On one side, the enhanced stratification of the upper water column resulting from global warming reduced the ~(226)Ra input from the depth, on the other, the temporal increase of biological production resulting from the climate-related ecosystem structure change strengthened the ~(226)Ra removal from the surface ocean. Both the physical and biological processes resulted in the decrease of surface ~(226)Ra concentrations in the North Pacific Subtropical Gyre. The temporal trend of surface ~(226)Ra concentrations was consistent with the trends of chlorophyll a, silicate, phosphate and primary production previously reported. This study provided ~(226)Ra evidence for the ecosystem shift under global change.     

上层海洋热力异常对西北太平洋热带气旋气候特征的影响

重点分析了1970-2003年期间西北太平洋的热带气旋活动特征与海洋表面温度、上层海洋的热力异常变化以及对流层低层的大尺度环流特征之间的关系.分析结果发现在西北太平洋海域,热带气旋活动趋势与上层海洋热力异常变化(上层海洋热含量)以及对流层低层的西风异常之间有着显著的相关关系,而与海洋表面温度无显著关系.并在此基础上探讨了这种关系存在的物理机制.