布袋沙障对流动沙丘地表风沙和土壤湿度的影响

为了解布袋沙障对风沙流和土壤湿度的影响,通过测定风速和采集地表0~30 cm输沙,同时对地下0~40 cm土壤含水率进行测试,分别研究1 m×1 m、2 m×2 m、3 m×3 m规格布袋沙障防风效能、粗糙度、输沙量和土壤湿度差异。结果表明,布袋沙障能够有效提高0~30 cm高度范围的防风效能,增加地表粗糙度,显著降低0~30 cm地表输沙量和改变风沙流结构。3种布袋沙障的防风效能顺序为1 m×1 m2 m×2 m3 m×3 m,1 m×1 m与其他两种规格布袋沙障的防风效能差异显著(P0.05),2 m×2 m和3 m×3 m规格布袋沙障的防风效能间无显著差异;粗糙度顺序为1 m×1 m2 m×2 m3 m×3 m对照,1 m×1 m、2 m×2 m和3 m×3 m规格沙障粗糙度分别比对照高91.31%、78.88%和76.26%,差异极显著(p0.001);0~30 cm输沙量顺序为对照3 m×3 m2 m×2 m1 m×1 m,对照的0~30 cm输沙量达到了71.43 g(/min·cm2),是布袋沙障的32.98倍,3种规格布袋沙障与对照沙丘2~10 cm和0~1 cm两层沙量的比值λ均大于1,说明在监测期内地表均处于风蚀状态。土壤含水率顺序为对照3 m×3 m2 m×2 m1 m×1 m,在0~20 cm土层此变化趋势明显,对照的土壤含水率分别比3 m×3 m、2 m×2 m、1 m×1 m规格沙障样地的土壤含水率高55.15%、58.63%和67.45%。     

布袋沙障对流动沙丘地表风沙和土壤湿度的影响

 为了解布袋沙障对风沙流和土壤湿度的影响,通过测定风速和采集地表0~30 cm 输沙,同时对地下0~40 cm 土壤含水率进行测试,分别研究1 m×1 m、2 m×2 m、3 m×3 m 规格布袋沙障防风效能、粗糙度、输沙量和土壤湿度差异。结果表明,布袋沙障能够有效提高0~30 cm 高度范围的防风效能,增加地表粗糙度,显著降低0~30 cm 地表输沙量和改变风沙流结构。3 种布袋沙障的防风效能顺序为1 m×1 m>2 m×2 m>3 m×3 m,1 m×1 m 与其他两种规格布袋沙障的防风效能差异显著（P<0.05）,2 m×2 m 和3 m×3 m 规格布袋沙障的防风效能间无显著差异;粗糙度顺序为1 m×1 m>2 m×2 m>3 m×3 m>对照,1 m×1 m、2 m×2 m 和3 m×3 m 规格沙障粗糙度分别比对照高91.31%、78.88%和76.26%,差异极显著（p<0.001）;0~30 cm 输沙量顺序为对照>3 m×3 m>2 m×2 m>1 m×1 m,对照的0~30 cm 输沙量达到了71.43 g/（min·cm²）,是布袋沙障的32.98 倍,3 种规格布袋沙障与对照沙丘2~10 cm 和0~1 cm 两层沙量的比值λ均大于1,说明在监测期内地表均处于风蚀状态。土壤含水率顺序为对照>3 m×3 m>2 m×2 m>1 m×1 m,在0~20 cm 土层此变化趋势明显,对照的土壤含水率分别比3 m×3 m、2 m×2 m、1 m×1 m 规格沙障样地的土壤含水率高55.15%、58.63%和67.45%。     

基于空气动力学的沙袋沙障气流场模拟

以空气动力学为理论基础,借助流体力学软件Fluent,对不同规格沙袋沙障近地表气流、风速廓线和防风效能等进行了模拟分析.结果表明:各监测断面风速廓线在距地表高度h≤0.5m时,变化差异较小;在h=0.5～2.0m高度范围内,风速呈递减趋势.近地表气流出现3个明显分区:加速上升区,低速下沉区和低速回流区,分别位于沙障防护工程的前上方、防护区上方和障格内.在低速回流区形成两个水平轴涡流,涡流中心流速最小.h=0.5m处成为沙袋沙障的风速分界点,h=0～0.5m时,沙障高度是风速主要影响因素;h=0.5～2.0m时,沙障规格是风速主要影响因素,2m×2m规格沙障效益显著.     

芦苇高立式沙障成束装置孔隙率控制机构的设计与试验

针对目前芦苇高立式沙障孔隙率间距控制难问题,研究设计了一种芦苇高立式沙障成束装置孔隙推送机构.机构的关键部件设计包括推送弧片的设计与参数确定、采用解析法对缓推凸轮的轮廓线的计算、空隙推杆的设计计算等.建立空隙推送机构三维模型,将模型导入ADAMS环境下,对虚拟样机进行运动学仿真分析,研究以缓推凸轮为驱动元件的机构运动规律,并研制出了孔隙距离控制推杆机构进行孔隙率控制试验,试验结果平均孔隙率为50.13%,验证了设计的正确性和合理性,可为后续全自动芦苇高立式沙障成束机的研发提供参考.     

沙坡头人工植被防护体系防风固沙功能价值评价

本文将沙坡头人工固沙植被防护体系防风固沙功能机制分为枝柴栅栏、草方格沙障和人工植被三部分,评价了该体系防风固沙功能价值.结果表明：沙坡头人工固沙植被生态系统每年拦截流沙物质量为2.79×10^8m^3,其中枝柴栅栏拦截1.76×103m^3,草方格沙障拦截8.5×10^5m^3,人工固沙植被拦截2.78×10^8m^3.利用机会成本法算出由此而产生的经济价值是5.93×10^8元.本文的研究结果对进一步准确评估沙坡头防护体系服务功能有一定的参考价值.     

青海省海晏县沙柳林土壤水分与土壤水库研究

采用烘干称重法对海晏县城和西海镇附近沙柳林地土壤水分进行研究.结果表明:位于河漫滩上的海晏城附近的沙柳林土壤含水量高,平均含水量为25.1%,土壤水分能够满足沙柳林的正常生长;位于一级阶地上的西海镇沙柳林土壤上部1m范围内含水量较高,平均含水量为19.3%,1m以下含水量很低,有土壤干层发育.这表明,在该区自然降水条件下,除地形低洼、地下水很浅的河漫滩地区之外,土壤水分不能满足人工林正常生长需要.该区沙柳林土壤水分收入小于支出,具有负平衡的特点.该区土壤上部1.0m深度范围内以粉砂为主,孔隙度较高,土质优良,但1.0m以下以粗砂和细砾石为主,土质较差.     

沙障防沙治沙技术研究综述

沙障是荒漠化防治领域广泛应用的一种治沙措施.对国内沙障应用以来沙障的设置类型、使用材料、命名方式、设置技术、防护效益、防腐研究等方面的工作进行了综述,总结了沙障应用中取得的成果和存在的问题,提出国内沙障研究中需要进一步完善的内容.     

南麂海区真鲷深水网箱养殖技术研究

2003年 4月 30日从福建沙埕购进平均体重 150 g的大规格真鲷鱼种 17633尾在南麂大沙岙半开放性海区深水网箱中进行试养,运输成活率高达 99.7 %,养至 2004年 5月 1日平均体重达 475 g,养殖成活率为 89.9 %,饵料系数为 8.38,投入产出比为 1: 1.297,毛利率为 22.9 %.此外,还对南麂海区深水网箱养殖真鲷的有关技术问题进行了初步探讨.     

不同固沙措施对民勤风沙口风速及粗糙度的影响研究

通过对民勤-雅布赖风沙口沙害综合治理体系设置的治沙措施,进行了抗风蚀、沙埋能力以及对风速、地表粗糙度影响力的观测与分析,结果表明:风沙口防护体系草方格、黏土、土工布沙障可大幅度提高地表粗糙度,分别为2.109,1.768,25.74;风蚀程度降低79％,49％,89％.并且通过综合防沙体系的建立,可使体系内风速降低65％,风蚀面积减小80％以上.总体上,治理1年后沙害程度减少了51.96％,沙害面积减少了88.4％,积沙量减少了87.6％.机械沙障防护下的人工直播灌草成活率得到大幅度提高,1年后覆盖度达到16％.初步总结出干旱地区通过采取工程固沙保护下的综合防护体系,固沙及阻沙效益明显.     

沿海木麻黄防护林不同配置模式的防护效应

为探讨配置模式对海岸防护林防护效应的影响,从2006年11月到2007年3月在东山岛用野外调查的方法对海岸木麻黄防护林的防护效应进行了研究.结果表明:木麻黄×厚荚相思混交林(1∶4)的防护效应＞厚荚相思×湿地松、刚果桉×湿地松＞厚荚相思×湿地松(3∶1);木麻黄林防护效应随林分密度和郁闭度增大而增大,密度为2205株/m2的林分比3375株/m2的林分提高2.4%,比875株/m2的林分增大15.7%.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

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.     

A computer generator for randomly layered structures

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

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

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。     

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.     

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

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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     

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