放牧对典型草原羊草微斑块优势种和土壤中微量元素的影响

以内蒙古呼伦贝尔鲁伦河流域克氏针茅草原为研究区域,通过对不同放牧强度下羊草微斑块样方调查,采集优势植物和土壤,分析Fe、Mn、Cu、Zn四种微量元素变化,探讨放牧对羊草斑块优势植物和土壤中Fe、Mn、Cu、Zn微量元素的影响。结果表明:随着放牧强度的增加,共有优势种羊草中Fe含量最高,其次为Mn、Zn,Cu含量最低。微斑块土壤中Fe、Mn、Cu、Zn四种微量元素的含量差异极显著,羊草中四种微量元素的含量均属于中等水平或低含量范围。土壤中Fe、Mn、Cu、Zn四种微量元素含量均低于国内外正常土壤平均含量。     

长江三角洲典型地区农田土壤速效钾时空演变特征及其驱动力

研究农田土壤速效钾的时空演变规律对改善土壤管理和提高土壤质量具有重要的指导作用．以长江三角洲地区的江苏省如皋市为例，对不同时期农田土壤速效钾的时空分异进行了研究．结果表明，自1982—1997—2002的20多年来，虽然速效钾在空间分布模式上变化不大，但近年来，空间分布趋于复杂化．土壤速效钾具有明显的时间分异特征，总体上经历了先下降后又有所回升的动态演变过程，在90年代中期土壤速效钾普遍亏缺，但近年来有显著回升．不同土壤类型速效钾的时空分异特征有明显差别．由江淮冲积物或长江现代冲积物发育而成的，质地较粗的雏形土（磨头系、郭园系和张黄港系）20年来持续下降，但下降幅度较小．由浅湖相冲积物发育而成的，质地较细的水耕人为土（白蒲系）和长江现代冲积物发育而成的，质地较细的潮湿雏形土（长青沙系）早期下降幅度较大，但近年来回升幅度也较大．其余土系则遵循先下降后上升的总体规律．影响土壤速效钾变化的驱动力分析表明，造成这些时空演变规律的主要因素包括：秸秆还田、施肥管理、种植结构和土地利用方式的改变等．且随着时间的推移，这些因素的影响趋于多元，导致农田土壤速效钾的空间变异性逐渐增强．     

海南垦区土壤微量元素的调查研究

本文着重介绍海南农垦地区土壤的微量元素现状。比较了不同土类、不同母质土壤的 Ca、Mg 以及 Cu、Zn、Mn、Mo、B 的含量水平,及其在不同类型土壤土层中的分布,并分析了几种微量元素的有效量与全量及有机质的关系。调查结果表明:海南垦区土壤 Ca 含量都很低;某些砂性土缺 Mg;Cu、Mn 皆较丰富,部分土壤缺Zn 和 Mo,而大部分土壤缺 B,水田缺 B 尤为普遍。     

青藏高原东南缘高山峡谷区舍饲牦牛与环境微量元素含量分析

研究青藏高原东南缘高山峡谷区舍饲牦牛与环境微量元素含量及关联性,采集5个县8个牦牛养殖场的组织样及饲料、土壤和饮水样品,采用ICP-OES等方法对微量元素含量进行测定.结果显示,牦牛肝脏中Cu含量为0.369mg/kg,低于一般含量10 mg/kg~40 mg/kg,可能处于缺乏状态.肝脏Fe元素含量为5.037 mg/kg,低于一般含量132mg/kg~188 mg/kg,处于缺乏状态;饲料中Cu、Mn、Zn、Co、Mo的含量,精饲料中Fe元素含量,以及土壤中Co、Mn、Zn元素含量均低于有关标准,处于缺乏状态;牦牛组织中B与Fe、Mn和Mo,Co与Cu、Fe、Mn和Mo,Cu与Mn和Mo,以及Mn与Mo和Zn呈显著正相关(P0.05或P0.01),表明具有同源性;饲料Co与Cu、Mn、Zn和Cu与Mn、Zn以及Mn和Zn呈显著正相关(P0.05或P0.01),表明具有同源性;肝脏Fe和Mo及肾脏Fe与饲料具有关联性;背最长肌和肝脏Mo与土壤具有关联性.以上结果表明,该地区组织和饲料中微量元素普遍处于缺乏状态,组织和饲料内大多数微量元素间都存在同源性.     

3种改良剂对烟叶微量元素含量和品质的影响

通过调查豫西烟田土壤微量元素Cu、Zn、Mn、Fe的含量状况,研究了3种常见土壤改良剂(土壤调理剂、聚丙烯酰胺、腐殖酸)对土壤微量元素有效性及烟草产量与质量的影响。研究结果表明:3种改良剂均对土壤有效Mn含量有显著的改良效果,施用后土壤有效Mn含量可增加42.85%,且三者之间无显著差异。对于有效Zn改良效果均不理想,但均可促进烟叶的Zn含量,施用腐殖酸烟叶Zn含量增幅最大,可达80.32%。施用腐殖酸、土壤调理剂和聚丙烯酰胺均可提高烟叶的产量,产量增幅分别为26.00%、76.88%和66.07%,施用腐殖酸和土壤调理剂可增加上等烟比例,分别比对照组增加了4.22%和5.33%。     

ASI法测定土壤有效Zn、Cu、Fe、Mn与植物吸收的相关性研究

本文应用ASI法测定我国北方主要耕地土壤的有效态zn、cu、Fe、Mn,根据测定值高低分别选取各土壤类型的十个土壤样本进行植物栽培的微量元素试验．结果表明,ASI—Zn、Cu、Fe、Mn测定值与小麦生物量均没有达到显著相关水平（n=40,P〉0．05）;ASI—Cu、Fe测定值与小麦吸收量均没有达到显著相关水平（n=40,P〉0．05）,ASI-Zn、Mn测定值与植物吸收量达到显著相关水平（n=40,P〈0．05）．以土壤ASI法临界值的2．5倍为补充土壤微量元素量,小麦吸收zn是有效且合理的,但是小麦吸收cu、Fe和Mn是无效的,表明ASI法的土壤微量元素丰缺指标在我国北方农田土壤应用尚需进一步研究．     

呼和浩特市和林格尔地区沙棘生化成分分析

对呼和浩特市和林格尔地区沙生植物沙棘中所含的常量元素、微量元素和17种氨基酸进行测定．结果表明，沙棘中的常量元素Ca、K、Na、Al、Mg在植株各部分中的含量顺序相同，皆为Ca〉K〉Na〉AE〉Mg；Fe、Mn、Cu、Zn4种植物所必需的微量元素含量顺序存在差异，表现为根：Fe〉Mn〉Cu〉Zn，主干：Fe〉Cu〉Mn〉Zn，侧枝：Fe〉Mn〉Cu〉Zn；沙棘中人体必需的7种氨基酸含量均较高．含量顺序为侧枝〉根〉主干．     

党参中铜、锰、铁、锌的形态分析

对中草药党参中微量元素Cu ,Mn ,Fe ,Zn的形态分析进行了研究 .用 0 .4 5 μm滤膜将其水煎液分成可溶态和悬浮态 .对于可溶态 ,用LSA - 10吸附树脂分成无机态和有机态 ,并且对水煎渣依次用CCl4和HCl进行提取 .火焰原子吸收法 (FAAS)测定各形态微量元素含量 .结果表明 :党参水煎液中 ,Fe以有机形态为主 ,而Mn的有机态比例仅占 2 .9% ,常规煎渣中仍留有大量有机态Zn .     

鄂尔多斯高原皇甫川流域不同土地利用类型土壤微量元素的比较分析

对鄂尔多斯高原皇甫川流域不同土地利用方式下土壤微量元素进行比较研究,结果表明:皇甫川流域土壤中Zn的含量普遍较低,远小于缺Zn临界值;Fe的含量在多数土壤中亦较低,小于缺Fe临界值;而Cu和Mn的含量却较高,大于临界值.不同土地利用方式下,根系集中分布的10～20cm土壤层中的元素含量除Mn以外,其他三个元素基本上以恢复样地最高,这说明恢复效果比较明显,土壤的养分状况已经有了明显的好转.各类土壤微量元素的剖面分布比较复杂,没有明显的规律性.不同微量元素的含量在植物不同生长期、不同样地表现出不同的变化特征,只有Fe元素表现出明显的季节动态.     

独一味中六种微量元素的形态分析

按照传统煎煮法对中药独一味中六种微量元素(Cu、Mn、Zn、Fe、Ca、Mg)的初级和次级形态进行提取,采用火焰原子吸收分光光度法测定其含量,并用正辛醇/水分配体系研究了提取液中这六种微量元素在模拟人体肠胃环境中的分配情况.结果显示:独一味中六种元素在原药中含量特征为Ca﹥Mg﹥Fe﹥Mn﹥Zn﹥Cu;总提取率为18.75~54.76%,浸留比为0.23~1.24.六种元素的可溶态含量均远低于颗粒态,而且大多为无机结合态,少量为有机态结合;Mn、Mg、Zn和Ca主要以游离形态存在,Cu和Fe却主要以不可交换的形态存在;Mg、Zn在正辛醇/水分配体系中的溶出性受酸碱性影响较大.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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