农田防护林带组合方式对近地面风速作用特征的影响

为了揭示农田防护林带组合方式对近地面风速的影响,通过实地空间多点观测,研究防护区风速分布特征。研究结果表明,对于垂直相交林带而言,根据林带对风速影响程度的差异可分为主林带和副林带,在主林带附近弱风区位于0～150m范围内,风速值主要在6.38～7.56m/s之间变化,而距主林带200～280m处风速值在8.06～9.23m/s之间。在副林带附近风速值相对比主林带附近高,风速降低较之主林带附近区域弱,说明该林带对这种风流特征的影响程度弱于主林带。在林网内,形成了一个全面的防护区,风速值小于旷野风速值,只在林缘附近1H范围内风速值接近旷野值11.0m/s,在林网中心区有一个风速低峰区,林网内风速最低值出现在林缘附近4～8H区域内,可见网状配置林带防护效果最佳。     

不同生长发育阶段木麻黄农田防护林的防风效应

为了探讨农田防护林的防风效果,2006年11月对东山岛单条木麻黄农田防护林带和两条林带内外区域的风速进行了测定.结果表明:农田防护林内外风速呈抛物线状变化,最小值出现在单条林带后10h处,两条林带后15h处,距离后移了5h,而且风速值在逐渐降低.空间表面图为波浪状曲面,等值线分布比较均一.弯曲不大,中间出现一些小的闭合区域.     

徐淮平原杨树林带的胁地规律

对徐淮平原杨树林带胁地段内小麦产量的变化规律进行分析。结果表明,农田林网内的小麦产量存在着明显的减产区、平产区和增产区。林带侧0．4H(H为林带平均高度)范围内为减产区,0．7H左右为平产区,0．7H以外为增产区;林带对其北侧和西侧小麦的影响严重,且影响范围较大,而在林带南侧和东侧的小麦所受胁地影响较轻;林木冠幅(平均投影面积)对近林带处小麦的产量影响较大。在影响农作物产量的主要因素中,树冠遮荫对小麦的生长发育有着更加明显的抑制作用;林带断根措施可有效防止根系从农田土壤内吸收水分和养分,能够在一定程度上降低林带树木根系的胁地影响。     

通风巷道围岩与空气换热的数值模拟

为有效利用巷道内排除的热空气,以大隆矿区矿井通风巷道为例,采用分离求解方法,对巷道围岩一空气换热系统进行三维数值模拟,分析巷道空气出口平均温度71P、巷道围岩与巷道内空气的平均总传热系数K、巷道空气平均出口热流密度q、风速口的变化规律。结果表明：v在0．2～1．0m／s时,耳较大;v越小,砟越接近于围岩初始温度。v在5．0～7．0m／s内,对K影响不大;当v〈5．0m／s时,K呈线性规律降低。v在0．2～5．0m／s时,q呈二次曲线渐变过程。丁随着”的减小、巷道长度的增加而增加。该结果为进一步研究围岩与空气的换热问题奠定了基础。     

广东省沙质海岸营造防风固沙试验示范林模式研究

进行了适生固沙灌,草的选草,草的选育,栽培以及及减轻沿海热带气旋危害并延缓沙土向内陆移动速度等的研究,营造乔,灌,草综合治试验试验模式示范林,并筛选出防风固沙效果好的4个大麻黄优良无性系,3个灌木和5个适于林带前沿至高潮线沙带种植的草木植物,从林带前沿到农田旱地设置 3道防风屏联,采取这些技术措施后,试验示范林内和林后风速降低了43．5－68．7％,4－5m/s风速已不再起飞沙,林内的自然植被增加,喜湿润的植物生长良好,防风固沙效果显著。     

普陀区风能分析

利用沈家门30年风速资料及近几年建设的8个自动气象站风速资料,对普陀区的风能资源特征量进行计算分析.结果表明,普陀区属于风能资源丰富区,具有很高的开发价值.年平均风速3.9～6.7 m/s,风速分布自西向东逐渐增大.风速≥3 m/s的年有效风速时为5 568～7 708 h,风速≥6 m/s的年有效风速时为2 206～4 699 h.平均风能密度最大值达298.5W/m2,最小值为130.4 W/m2.风能随高度而明显增加,而50～70 m这层厚度上风能变化不大.并分析了4个最佳风能区风速和风向频率,可以极大提高风能的利用率.     

铸态淬火低合金马氏体白口铸铁磨球的研制

在砂型铸造条件下．含 １．7～2．3％C、0．5～１．0％Sｉ、0．4～１．0％Mn、0．3～0．7％Cr、0．3～０．7％Ｃｕ的白口铸铁磨球经１．０～１．5％１＃稀土硅铁合金、０．１％A１处理，在８００～900℃利用铸造余热水淬一定时间，并经280～350℃回火，硬度达HRC55以上．在有效高度为4．２m的磨球跌落试验机上．跌落破碎次数超过 5万次．DTM250／390球磨机工业应用试验结果表明．磨制无烟煤的吨煤磨球磨耗比稀土低碳白口铸铁磨球降低44．8％．     

包兰铁路沙坡头段防护体系近地面流场特征

基于地形和流场实测，研究了包兰铁路沙坡头段铁路防护体系近地面流场沿NNW-SSE方向的变化．结果表明，由于地形变化以及人工植被和草方格的存在，防护带内等风速线沿风向呈逐渐变疏和抬高的趋势，各高度的风速总体上呈递减趋势，风速放大率为负；沙丘迎风坡风速放大率为正，流动沙丘迎风坡风速放大率高于固定沙丘迎风坡．沙丘背风坡2．5m高度内风速放大率总体为负．防护带内的固定沙丘背风坡气流通体减速，各高度的风速放大率全部为负，平均为一1．48％／m．防护带内地表空气动力学特征发生变化，其中沙丘迎风坡地表风速廓线接近于对数率；人工植被带地表空气动力学粗糙度显著高于流沙区．     

不规则波对透空式建筑物上部结构冲击作用时域分析

对透空式建筑物上部结构的不规则波冲击作用进行了试验研究．试验靶谱是JONSWAP谱，试验中选取的入射波波高H1/3的范围为0．10～0．25m，谱峰周期Tp的范围为1．0～2．0s，结构物底面距静水面的高度s与入射波高H1/3之比的范围为-0．1～0．4．给出了不同试验组次的结构物底面所受波浪冲击压力的统计分析结果，得出结构物底面所受波浪冲击压力的特征值沿结构物底面分布特性．s／H1/3对作用于结构物底面的冲击压力峰值有很大影响，冲击压力峰值最大值出现在s／H1/3=0．1～0．2．     

不同取代度的甲壳素磷酸酯钾对番茄种子萌发的作用

用甲壳素合成1^#～7^#甲壳素磷酸酯和甲壳素磷酸酯钾，分别测定1^#～7^#甲壳素磷酸酯的取代度、将甲壳素磷酸酯钾配成O．5mg／L，2mg／L，5mg／L．10mg／L，20mg／L溶液，以蒸馏水为对照，进行番茄(Lycopeysicon esculentum)种子的浸种发芽实验。浸种46．5～76．5h；培养温度29．5C；每只培养皿50粒，每种浓度重复3次。结果表明：6^#、7^#甲壳素磷酸酯钾对番茄种子不具有促进作用；而1^#～5^#甲壳素磷酸酯钾对番茄种子有不同程度的促进作用，其质量浓度以0．5mg/OL～20mg／L为最佳，其中1^#、2^#、3^#、4^#、5^#甲壳素磷酸酯钾对番茄种子的发芽率分别比对照组增长6．7％、17．4％、16．7％、6．0％、16．0％。     

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).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.