大兴安岭中段晚二叠世林西组介形虫化石及环境意义

晚二叠世-中三叠世在中亚造山带东段构造演化过程中是承上启下的关键地质时期,所以晚二叠世林西组沉积环境对研究古亚洲洋闭合这一重大问题具有重要意义。大兴安岭地区晚二叠世林西组曾有双壳、叶肢介、植物及孢粉化石记录,但鲜有介形虫化石报道。在大兴安岭中段林西组研究中首次发现介形虫化石,经初步研究,主要分子有Kemeroviana,Volganella,Iniella,Qitaina,Darwinuloides,Palaeocypridopsis,Tomiella,Darwinula和Urumqiella等,暂划为Volganella-Kemeroviana组合,其时代为晚二叠世。与俄罗斯地台晚二叠世介形虫化石群关系较为密切,部分属种曾见于我国新疆准噶尔盆地和塔里木盆地。从介形虫化石组合特征和保存特点来看,其生存环境为淡水湖泊,故认为这一地区的林西组为陆相沉积。     

GPS观测得到的天津地区的现今变形

1995年为了监测天津市的地面变形，配合地面沉降的精密水准测量，在天津市布设了一个GPS监测网。从1995年开始，每年的10月或11月进行一次精密GPS测量，到2001年已连续观测7年，在重新系统处理这7年资料的基础上，对天津地区的现今变形进行了研究，并与同时进行的精密水准复测的垂直变形结果进行了比较。结果表明，在扣除了天津地区随同欧亚板块在地球表面的整体运动之后。天津地区仍然有以东向运动为主要特征的水平运动，年速率约为8.4mm/a，这与整个华北地区的东向运动一臻。天津地区的垂直变形主要是因抽用地下水，油，气引起的地面沉降。用GPS测得的沉降量与用精密水准得到的结果相当一致，天津地区的垂直变形主要是因抽用地下水，油，气引起的地面沉降，用GPS测得的沉降量与用精密水准得到的结果相当一致，其偏差均方根值为11.6mm/a。据此对天津地区的地面沉降监测问题提出了建议。     

Zoospores of Undaria pinnatifida: their efficiency to attach under different water velocities and conjugation behavior during attachment

In the invading course of Undaria pinnatifida, zoospore attachment in a dynamically changed subtidal water environment is crucial for the establishment of a potential population in alien waters. Among many abiotic factors that may interfere with the attachment process, water velocity is the most important one. In this investigation, the effect of water velocity on zoospore attachment of U. pinnatifida was investigated in an artificially designed system. It was found that freshly released zoospores that were transported by water flowing at 0 -16 cm/s showed no difficulty in attaching the smooth surface. Zoospore attachment decreased at elevated water flowing rates. At 70 cm/s no spore attachment occurred. Spores that have settled on glass slide for up to 1 h could not be stripped away by flowing water at a rate of 129 cm/s, the same was true of the 20 d old filamentous gametophytes. It was found that more than 70% of free-swimming zoospores tended to settle down adjacent to the settled spores and formed conjugated clusters from two up to a few hundred cells in still culture.     

Nonculturability of the pathogenic Vibrio parahaemolyticus in live culture of Grateloupia turuturu is associated with bacterial attachment to the algal thalli

The invasive red alga Grateloupia turuturu Yamada could turn Vibrio parahaemolyticus into nonculturable state in live algal culture. In order to elucidate the mechanism of such an effect, a series of culture experiments were performed in this investigation based on three hypothesized causes, namely bacterial attachment, production of reactive oxygen species (ROS) and the discharge of water soluble secondary metabolic compounds. The results reveal that attachment to the thallus surface of G. turuturu was the major reason for the decrease of V. parahaemolyticus in seawater. Further investigations show that V. parahaemolyticus attachment to the surface of algal thallus in live cultures of seaweeds was a common phenomenon. However, the disappearance of the culturability of V. parahaemolyticus occurred only on the thallus of G. turuturu over 72 h among all six algal species tested. Electron microscopic scanning shows that most of V. parahaemolyticus attached to G. turuturu changed from the initial normal bacilli to coccoid-shape after 72 h. The enclosure experiments by enclosing the algal thallus in tubes demonstrate that the nonculturability of V. parahaemolyticus in the water of live culture of G. turuturu occurred after the physical contact of the V. parahaemolyticus to the alga. The capacity of G. turuturu in affecting the culturability of V. parahaemolyticus was not influenced after inhibition of photosynthesis by treatment of 3''-(3,4-dichlorophenyl)-1'',1''-dimethyl urea (DCMU) at non-lethal levels. Production of reactive oxygen species after addition of live culture of bacteria was excluded by on-line analyzing the oxidation of dichlorohydrofluorescein (DCFH) to dichlorofluorescein (DCF) in the presence of peroxidase on a VersaFluor fluorometer.     

基于室内路网的跨楼层路径规划技术的设计与实现

随着室内定位技术、BIM-GIS技术和室内地图研究的发展,室内位置服务需求日益旺盛。作为室内位置服务的关键技术之一,室内路径规划成为研究与应用热点。但是早先的路径规划技术往往基于单层网络拓扑模型而设计,由于模型缺少楼层之间的连通信息,而不能实现跨楼层导航算法分析;而后随着跨楼层导航算法的出现,跨楼层的路径规划、导航及定位得以实现,但这些跨楼层导航算法基于楼层连接通达规则,往往需要多次遍历楼层信息,运算效率低下。针对这一问题,本文利用电梯、扶梯、楼梯等楼层间连接信息,设计、实现了基于楼层连接表的室内多层路网分析模型,并采用逐层分析的方法和多次网络分析,实现室内跨楼层的带有多个途经点路径分析。整个技术框架包括跨楼层路网生成模块、位置点接收模块、网络分析模块、循环控制模块。算法方面,本研究采用双向遍历的A*最短路径分析算法,通过网络路径分析,最终将满足约束条件的规划路径显示在移动设备上,帮助用户实现跨楼层、多途经点的定位与路径导航。     

不同气候适宜区的橡胶产胶潜力研究

基于2000-2015年MODISNPP遥感数据,利用橡胶产胶潜力模型得到了中国橡胶主产区年橡胶产胶潜力;利用橡胶树种植气候适宜性区划的研究成果,得到了中国橡胶主产区橡胶气候适宜区分布;在此基础上分析了不同气候适宜区橡胶产胶潜力的差异及不同高程上橡胶产胶能力的差异.结果表明:(1)中国橡胶主产区中,云南橡胶产胶潜力最高...     

杭州湾北岸更新世以来沉积环境记录及古气候变迁

文章通过对杭州湾北岸孔深为237.80 m的BZK04钻孔进行沉积物岩性、微体古生物、孢粉组合、粒度含量、古地磁和OSL测年的综合分析,讨论研究区更新世以来沉积环境演变及古气候变迁特征,建立第四纪多重地层划分对比框架。结果显示, BZK04孔岩心自下而上可分为基岩长河组碳质泥岩（Ech）和早更新世以来的嘉兴组（N-Qp1 j）、前港组（Qp2q）、东浦组（Qp3d）、宁波组（Qp3n）、镇海组（Qhzh）地层;有孔虫鉴定为11属17种,其中包括16种底栖有孔虫,1种浮游有孔虫;介形类鉴定为8属8种;孢粉分析显示含37种类型,其中木本植物花粉18种,草本植物花粉11种,蕨类孢子8种,孢粉组合中木本植物含量最高,约为85.1%,蕨类孢子次之,约为8.7%,草本植物花粉含量仅为6.3%。根据岩性分层特征、沉积相、孢粉、有孔虫及介形虫以及粒度分布频率曲线对钻孔的沉积环境进行综合分析,可将沉积环境记录划分18个孢粉组合带和七个古气候旋回变迁,其中早更新世为河流相和河湖相沉积,揭示第三暖期—第4冷期的两个古气候旋回;中更新世以河流相、湖泊相和河湖相为主,揭示第五暖期—第6冷期的两个古气候旋回;晚更新世以潮坪相、河口湾相、浅海相沉积为主,对应第七暖期—第8冷期的两个古气候旋回;全新世时期为潮坪相和河湖相沉积,对应大西洋期和亚北方期。研究结果为进一步掌握长江三角洲南翼更新世以来的第四纪沉积环境变化、地层划分和古气候演变等提供基础资料。     

利用最大降水量拟合福州城市内涝积水深度的误差分析

利用2015—2016年福州城区内涝和地面气象观测资料,分析内涝成因、最大降雨量与积水深度的关系,建立城市内涝积水深度拟合方程,并对拟合效果进行了检验。结果表明:1)导致福州城市内涝的突发性原因占26%,是城市管网等数据更新困难的主因,非突发性原因占74%;2)在3次不同天气系统的降雨量拟合结果中,雨季降水过程拟合平均绝对误差最小,午后雷雨天气降雨过程拟合平均绝对误差最大;3)对内涝积水深度负拟合值进行归零处理和阈值限定后,其结果均与实况相符;4)基于最新数据资料所得拟合值的误差更小。     

基于ArcEngine的三维地形可视化系统设计与实现

以Visual C#.NET为开发平台,以ArcEngine为开发组件,详述了三维地形可视化功能的实现方法和关键技术,设计并实现了包括地形表面生成、三维场景显示、地形因子分析及通视分析等功能的基于ArcEngine的三维地形可视化系统.