华东石油局油田开发“十五”发展战略及2015年远景展望     

汪深 《江苏地质》2002,26(1):54-56

随着第十个五年计划的到来，华东石油局的油田开发工作也进入了新时代，面临着我国加入世界贸易组织（WTO）的新形势，油田开发工作面临着新挑战，在新形势下和新挑战面前，华东石油局根据自身拥有的资源状况科学合理地制定了油田开发“十五”发展战略。  相似文献   

Scum in Nutrient Removal Plants: The Role of Carbon Sources in “Microthrix parvicella” Growth     

Hilde Lemmer  Elisabeth Müller  Margit Schade 《洁净——土壤、空气、水》2002,30(4):207-211

Scum formation is a widespread problem in activated sludge nutrient removal plants. It often comes along with an excessive development of the filamentous bacterium “Microthrix parvicella” stabilizing the flotation process. As “M. parvicella” was found to depend on long‐chain fatty acids (LCFA) as sole carbon source not only in vitro but also in situ, some options of in‐situ substrate supply are discussed. Wastewater concentrations of fatty acids in the range of 2 to 15 mg L^‐1 and homologue concentrations from synthetic surfactant degradation below 10 mg L^‐1 rule out these substrates as source for excessive biomass production. They might, however, well be suitable for start‐up of a “M. parvicella” population. Build‐up of excessive biomass might rely on fatty acid supply originating in cell walls of lysed stationary phase bacteria of long residence time sludge fractions such as scum layers. Moreover, biogenic surfactants such as rhamnolipids have been proved to be an excellent carbon source for excessive biomass production in vitro.  相似文献   

A late Pleistocene long pollen record from Lake Urmia, NW Iran   总被引：4，自引：0，他引：4  

Morteza Djamali  Jacques-Louis de Beaulieu  Madjid Shah-hosseini  Valrie Andrieu-Ponel  Philippe Ponel  Abdolhossein Amini  Hossein Akhani  Suzanne A.G. Leroy  Lora Stevens  Hamid Lahijani  Simon Brewer 《Quaternary Research》2008,69(3):413-420

A palynological study based on two 100-m long cores from Lake Urmia in northwestern Iran provides a vegetation record spanning 200 ka, the longest pollen record for the continental interior of the Near East. During both penultimate and last glaciations, a steppe of Artemisia and Poaceae dominated the upland vegetation with a high proportion of Chenopodiaceae in both upland and lowland saline ecosystems. While Juniperus and deciduous Quercus trees were extremely rare and restricted to some refugia, Hippophaë rhamnoides constituted an important phanerophyte, particularly during the late last glacial period. A pronounced expansion in Ephedra shrub-steppe occurred at the end of the penultimate late-glacial period but was followed by extreme aridity that favoured an Artemisia steppe. Very high lake levels, registered by both pollen and sedimentary markers, occurred during the middle of the last glaciation and late part of the penultimate glaciation. The late-glacial to early Holocene transition is represented by a succession of Hippophaë, Ephedra, Betula, Pistacia and finally Juniperus and Quercus. The last interglacial period (Eemian), slightly warmer and moister than the Holocene, was followed by two interstadial phases similar in pattern to those recorded in the marine isotope record and southern European pollen sequences.  相似文献   

遥感图像分类自动选取最优波段组合的方法研究     

倪希亮  江涛 《测绘科学》2008,(Z1)

在遥感影像计算机自动识别与分类中,选取最佳的波段子集对地物进行分类对提高分类精度至关重要。根据统计学原理,遥感影像中属于某类别地物的特征向量服从正态分布,训练样本的正态性检验是关键,基于此理论,本文利用TM影像数据,通过检验所选取的训练区的正态性与否,让计算机自动的选取最优的波段组合,并对分类的精度进行评估。研究表明,计算机自动选取最佳波段组合后对分类精度的预先评估,较常规分类后再进行数据检验精度评估方法方便,快捷,省时,省力。  相似文献   

ICP—OES测定地球化学样品中La，Y，Ba     

赵庆令  武殿喜  唐洪敏  徐兴臣  马强 《山东地质》2008,24(2):12-14

水系沉积物、土壤等试样用HF-HCl-HNO3-HClO4混酸消解后,以8％（v／v）HNO3溶解于渣,建立了测定地球化学样品中La,Y,Ba 3种微量元素的电感耦合等离子体发射光谱（ICP-OES）方法。方法测定限（μg／L,10SD）为：La 6．0,Y 1．0,Ba 1．0。精密度（RSD％,n=11）为：0．20～1．50,经国家一级地球化学标准物质的分析验证,结果与标准值吻合,该方法现已用于区域化探试样的分析。  相似文献   

VLBI标准接口的发展     

殷妮  张秀忠 《天文学进展》2007,25(1):74-83

VLBI标准接口是近年来在VLBI技术中诞生的一个新概念,它旨在解决多年来各VLBI数据传输系统不兼容的问题．该文阐述了VLBI数据传输系统的发展历史,包括传统的记录／回放系统和新兴的网络数据传输两方面的内容;说明了VLBI标准接口的作用和意义;并分别介绍了VLBI标准接口规范3方面的内容:VLBI标准接口件规范(VSI-H)、VLBI标准接口软件规范(VSI-S)和VLBI标准接口网络规范(VSI-E)．  相似文献   

A new upscaling method for fractured porous media     

《Advances in water resources》2015

We present a method to determine equivalent permeability of fractured porous media. Inspired by the previous flow-based upscaling methods, we use a multi-boundary integration approach to compute flow rates within fractures. We apply a recently developed multi-point flux approximation Finite Volume method for discrete fracture model simulation. The method is verified by upscaling an arbitrarily oriented fracture which is crossing a Cartesian grid. We demonstrate the method by applying it to a long fracture, a fracture network and the fracture network with different matrix permeabilities. The equivalent permeability tensors of a long fracture crossing Cartesian grids are symmetric, and have identical values. The application to the fracture network case with increasing matrix permeabilities shows that the matrix permeability influences more the diagonal terms of the equivalent permeability tensor than the off-diagonal terms, but the off-diagonal terms remain important to correctly assess the flow field.  相似文献   

一例长生命史雷暴云分裂过程的回波特征   总被引：9，自引：8，他引：1  

张鸿发  左洪超  陈成品  郭三刚 《高原气象》2004,23(1):40-47

在对平凉冰雹云演变规律研究中,发现一例长生命史强雷暴云分裂成两个不同移动方向的单体雹云。结合探空资料和环境风场,分析了此个例强雷暴云分裂过程的回波特征。结果表明,在强风切变环境中,u与v分量呈反相关,且随高度增强,低层1～3km为弱气旋旋转,中层3～8km为强反气旋旋转,上层8km以上是强气旋旋转。这对右移雷暴云发展中有优势引导作用,导致强雷暴云上层偏向分离发展,分裂发生在强雹暴云有强下沉气流阶段。分裂后,左、右移单体各自维持发展,并产生降雹。整个雷暴发展演变过程维持长生命期,回波特征有四个不同阶段。  相似文献   

基于电场总场矢量有限元法的接地长导线源三维正演   总被引：7，自引：6，他引：1       下载免费PDF全文

李建慧  Colin G.Farquharson  胡祥云  曾思红 《地球物理学报》2016,59(4):1521-1534

电磁场数值模拟的背景场/异常场算法是三维正演的有效策略之一,优点为采用解析法计算电磁场背景场代替场源项、克服了场源奇异性,缺点为不适用于发射源布置于起伏地表或背景模型复杂的情形.总场算法是直接对电磁场总场开展数值模拟,其难点是有效加载场源、保证近区与过渡区数值解精度.本文以水平电偶源形式分段加载接地长导线源,并以电场总场Helmholtz方程为矢量有限元法控制方程,实现了基于非结构化四面体网格剖分的接地长导线源频率域电磁法三维正演.通过与均匀全空间中水平电偶源产生的电场解析解对比,验证了本文算法的正确性,并分析了四面体外接圆半径与其最短棱边的最大比值和四面体二面角最小值对数值解精度的影响规律.通过与块状高导体地电模型的积分方程法、有限体积法和基于磁矢量势Helmholtz方程的有限元法数值解对比,进一步验证了本文算法正确性,同时说明了非结构化四面体网格能够更加精细地剖分电性异常体,利于获得精确数值解.  相似文献   

黄河上游夏季流量对气候变化的响应及未来趋势预估     

刘彩红  杨延华  王振宇 《地理科学进展》2012,31(7):846-852

本文从气候变化的角度出发, 研究黄河上游龙羊峡水库夏季流量与流域气候条件的响应关系及流量预估模型, 并根据区域气候模式输出数据降尺度生成的未来气候情景, 对未来龙羊峡夏季水库流量进行了预估。结果表明:近35 年来, 黄河上游夏季气温升高、蒸发增大, 降水略有减少;黄河上游龙羊峡水库平均入库流量呈递减趋势, 夏季流量对流域降水量、平均最高气温及最低气温的响应显著;未来两个时期(2020s、2030s)龙羊峡夏季流量均较基准期(1988-2010 年)减少, 但在不同气候变化情景下流量变化有所差异, 其中A2 情景下夏季平均流量分别减少23.9%(2020s)和19.8%(2030s), B2 情景下分别减少14.4%(2030s)和17.3%(2030s), 据此, 未来气候变化对黄河上游流域夏季流量的可能影响将弊大于利, 但仍具有较大不确定性。  相似文献