The paranthurid isopod crustacean Paranthura nigropunctata (Lucas, 1846): first record from the Atlantic coast of Morocco

The littoral paranthurid isopod crustacean Paranthura nigropunctata (Lucas, 1846) is recorded for the first time from the littoral of El Jadida located on the Atlantic northwest coast of Morocco. Specimens were obtained from the invasive brown seaweed Sargassum muticum and the natives Bifurcaria bifurcata and Cystoseira tamariscifolia in January 2015. This new record further confirms a significant southward distribution of P. nigropunctata and contributes to the knowledge of the biogeography of this isopod. Heretofore, the species was only known from the western and eastern Mediterranean and some Atlantic coasts. The present finding is the first of the species from Moroccan Atlantic shores, and suggests that the species may also be present in other coastal localities from Morocco and Africa. Some data on morphology, ecology and spatial distribution of the species are provided.     

非开挖技术与铺管工程的优化设计

本文论述了非开挖铺管技术在工程中的应用前景及其工艺特点,提出了应将开挖技术与管线铺设的线路优化设计相结合,而且说明图与网络技术能更方便地用于非开挖铺管的线路优化步指出了利用非开挖技术可使铺管工程的线路设计达到最优。     

一种特殊类型硅质岩——浮石状燧石

一种较为少见的特殊硅质岩产于南京及巢湖地区的下二叠统孤峰组地层中。它的显著特征是岩石中存在大量菱形和不规则状孔隙,孔隙周边和孔隙间主要由微晶石英组成。通过对该岩石的成分和结构等特征的研究,认为它是一种交代碳酸盐岩成因的硅质岩,并定名为浮石状燧石。     

ENTRAINMENT FUNCTION OF SUSPENDED SEDIMENT IN OPEN CHANNELS

1　ＩＮＴＲＯＤＵＣＴＩＯＮ　Ｒｉｖｅｒｆｌｏｗｓｗｉｔｈｓｕｓｐｅｎｄｅｄｓｅｄｉｍｅｎｔｓａｒｅａｍｏｎｇｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｆａｃｔｏｒｓａｆｆｅｃｔｉｎｇｔｈｅｇｅｏｍｏｒｐｈｉｃｅｖｏｌｕｔｉｏｎ.Ａｋｅｙｆｅａｔｕｒｅｏｆｔｈｉ...     

LABORATORY EXPERIMENTS ON NAVIGATION-INDUCED BED SHEAR STRESSES AND SEDIMENT RESUSPENSION

IINTRODUCTIONDependingonflowandoperatingconditions,navigationtrafficmaycausesignificantresuspensionofdepositedsediment.Jnanumberofsituationsresuspensionofdepositedsedimentcanhavesevereenvironmentalrepercussions.Forinstance,ifthesedimentcontainscontaminants,thecontaminantsmaybereentrainedwiththesediment,taintingthewaterquality(Erdmannetal.,1994).Inothersituations,..evedincreasesintheamountofcleansuspendedsedimentcanbedetrimentalforaquaticplantsandanimals(Garcfaetal.,1998).Inordertoassesst…     

FIELD INVESTIGATION INTO DEBRIS FLOW MECHANISM

1.INTRODUCTIONDebrisflowisadistincttypeofmassmovementcommonlytriggeredbyintenserainfallandmeltingsnowonsteephillslopes.Althoughgreateffortshavebeenmadeinthestudyofthemechanismofthemotion,considerableambiguitypersistsconcerningtheinitiationandmotionofdebrisflow.Debrisflowcanbeinitiatedinsteepslopebecauseofthehighgravitationalforceandcanalsobetriggeredbyheavyrainstormongentleslopebyhighscouringcapacityofthetorrentialflood.Debrisflowisturbulentbecauseofitshighflowvelocityinsomecircumstancesa…     

空间域位置相关法道间插值

为了消除地震资料空间采样不够造成的空间假频现象,在ｃｌａｅｒｂｏｕｔ空间２－Ｄ预测误差滤波器的启示下,本文提出了空间域位置相关法道内插值,在地面实际资料处理中都取得了良好的效果。     

黔西南高砷煤中砷存在形式的初步研究

利用电子探针、扫描电镜_能谱分析、X衍射分析、低温灰化、透射电镜、X射线吸收精细结构分析、化学成分分析结果对黔西南高砷煤中砷的存在形式进行了初步研究 ,高砷煤中的砷主要以 5价 (含砷磷酸盐和砷酸盐 )的形式存在 ,少量砷以含砷硫化物如含砷黄铁矿、毒砂、雌黄 ( ?)形式存在 .在砷含量最高的H2样品中可能主要以有机砷的形式存在 .     

南海颗粒有机碳通量的垂向变化及早期降解作用的标志物

南海不同水层的颗粒有机碳通量与表层沉积物有机碳积累率的对比 ,以及氨基酸、氨基糖、糖类物质的组成变化表明 ,南海水柱中的颗粒有机碳主要来源于近期生长的海洋浮游生物 ,仅有 1.4%～ 1.6 %初级生产力产生的有机碳进入深海水柱 ,而在深海盆地沉积物中积累的有机碳仅占初级生产力的 0 .2 2 %以下 .颗粒有机物通量与组成改变主要发生在表层数百米以及底层海水与沉积物界面之间 ,而在中下水层变化较小 . (TAA+TSUG)OC ,AA/AS ,Gluam/Galam ,Arom .AA/Non Prot.AA ,ASP/b ALA ,GLU/g ABA等指标在颗粒物沉积过程中逐渐减少 ,指示了有机物质的早期降解作用     

秦岭-大别造山带下地壳拆沉作用

提供了秦岭-大别造山带下地壳拆沉作用的地质、地球物理、地球化学证据,建立了下地壳拆沉作用的化学地球动力学模型.综合研究表明,大别-苏鲁地区的榴辉岩是最可能被拆沉的物质,现今秦岭-大别地区地壳较为亏损的Eu,Sr,Cr,Ni,Co,V和Ti含量要求被拆沉的榴辉岩质下地壳累计厚度为37～82km.秦岭-大别造山带现今众多地质、地球物理和地球化学特征可较好地用下地壳拆沉作用来解释.