废弃线路板低温环境下弯曲性能的试验研究

针对废旧线路板常温下韧性强、难破碎的情况,对线路板在低温环境下弯曲强度进行试验研究。试验结果表明,线路板的弯曲强度在低温环境下呈现出先减小后增加的趋势,在-30℃附近达到最小值,且随温度的降低脆性明显增强,这一发现对于废旧线路板的破碎解离的研究提供了有力的基础支持。     

废旧电路板低温改性研究

介绍了电路板的组成和类型，重点研究了废旧电路板在低温状态下冲击强度、弯曲强度和剪切强度的改性变化。实验结果表明，冲击强度和剪切强度在-30℃时变化明显。在此基础上进行了粗碎实验和细碎实验，先使用ZKB-2型双辊式剪切破碎机将电路板破碎到20mm×20mm的块状，测试在低温状态下的功耗并计算其生产能力，在-30℃～-10℃范围内，生产能力可提高约17％，再降低温度会使产品质量受到影响。然后使用R型冲击破碎机对废旧电路板进行细碎实验，将物料破碎到3mm以下，并记录在不同工况下的参数。实验结果表明在-30℃左右平均功率下降得较快，冷却5min对低温改性最有利。     

PP/MMT复合材料的制备及性能研究

采用甲基丙烯酸甲酯(MMA)与PP接枝共聚物(PP-g-MMA)为界面相容剂,在熔融共混的条件下,利用螺杆挤出机制备PP/MMT复合材料,对其流动性能及力学性能进行了研究。结果表明:PP-g-MMA的加入提高了PP与O-MMT的相容性,当PP-g-MMA用量为20wt%,O-MMT的用量为3wt%时,力学性能最佳:拉伸强度提高了17.46%;常温下冲击强度提高了91.05%;低温(-20℃)条件下的冲击性能比常温下提高了40.29%,比低温下的纯PP提高了246.78%。     

高强钢Q460C对接焊缝低温冲击韧性试验

目的研究焊接高强度钢材Q460C低温下的断裂性能特征,以获得其对接焊件韧性受低温变化影响的规律,为此种钢材在低温环境下的应用提供试验依据.方法制备焊缝区及热影响区标准冲击试件,利用力学实验室低温环境保温箱及SANS型号摆锤式冲击试验机设备,对不同温度点下的试件进行冲击试验;并对试验数据用玻尔兹曼函数拟合,且对冲击试件断口电镜扫描分析.结果热影响区和焊缝区冲击韧性均随温度降低的下降而降低,而且热影响区的冲击功值较焊缝区的低;-60℃与-40℃温度下冲断的断口均呈现出显著的脆断特征.结论 Q460C高强度钢材焊缝区与热影响区有较明显的低温冷脆倾向.     

不同粉煤灰掺量的混凝土抗冻融性能研究

通过液压伺服试验系统,研究不同粉煤灰掺量下混凝土的抗冻融性能.对不同粉煤灰掺量的混凝土试块分别进行冻融循环试验,在不同循环次数下对试块进行单轴压缩强度测试及质量变化测定,并研究了混凝土的冻融损伤演化方程.结果表明,在混凝土中掺入一定量的粉煤灰能够改善其抗冻、抗裂性能,并且掺有粉煤灰的混凝土的后期强度大于普通混凝土后期强度.同时分析了混凝土的冻融损伤本构关系,为今后研究粉煤灰混凝土的冻融寿命提供了试验基础和理论依据.试验所得结论对于低温环境下混凝土在实际工程中的应用具有参考价值.     

低温风洞防护结构设计与强度校核

防护结构作为低温风洞内绝热系统的一个重要的子系统,具有隔绝绝热单元与低温介质,降低冷量损耗,形成气流通道的作用。然而,其在风洞运行过程中不断承受着风洞运行的低温载荷和交变压力载荷,为此,本文重点开展了防护结构设计和强度校核研究。首先,对防护结构进行了总体设计,明确了各部件尺寸和材料;然后,建立了防护结构三维有限元模型,根据低温风洞运行的最恶劣工况对防护结构进行了强度分析;最后,对防护结构进行了低温环境下的交变压力冲击试验。结果表明：设计的防护结构满足风洞运行工况下的强度要求,但在支撑件附近存在冷量损耗,这对我国将来自主开展大型低温风洞的设计建设具有重要的借鉴意义。     

低温下钢-混凝土组合结构疲劳试验和极限承载力

针对钢-混凝土结合梁在青藏铁路上的应用情况,模拟青藏铁路线的温度环境,用专门研制的低温设备(最低温度能保持在-50℃以下),对由14MnNbq钢构件、直径为22 mm的栓钉(下称ψ22栓钉)和强度等级为C50的混凝土组成的钢-混凝土组合件作了低温疲劳试验和极限承载力试验.试验中,考虑了钢板的轧向和环境温度变化等因素对组合件承载力的影响,研究了低温下ψ22栓钉的破坏形式,疲劳承载力和极限承载力等问题,并将低温下的试验结果同常温下的试验结果进行了对比.研究结果表明:在同等荷载下,ψ22栓钉在-50～0℃的低温环境下疲劳寿命比在室温下的疲劳寿命长,且有温度越低,抗疲劳性能越强的趋势;钢板轧向对栓钉疲劳寿命影响很大,但对栓钉极限承载力没有明显影响;14MnNbq钢材质优良,转变温度低于-50℃.在温度为-50℃时,栓钉焊在14MnNbq钢板上对钢板材质无影响.     

HTRB600级高强钢筋高温下的力学性能

为研究600 MPa级高强钢筋高温下的力学性能,对HTRB600级热处理高强钢筋进行高温下的拉伸试验,分别测得其在20,200,300,400,500,600,700及800℃高温下的弹性模量、比例极限、屈服强度、极限强度及应力-应变曲线.试验结果表明:HTRB600级高强钢筋高温下屈服强度、极限强度、比例极限与弹性模量均随着温度的升高而显著降低.500℃时其高温下的弹性模量、比例极限、屈服强度与极限强度降低为不足常温下的50%,800℃时已不足常温下的10%.高温下HTRB600级高强钢筋应力-应变曲线随温度的升高逐渐趋于圆滑,当温度达到200℃时,屈服台阶就已消失.600 MPa级钢筋高温下屈服强度和极限强度的降低程度明显大于其他钢筋500 MPa以下强度的钢筋.最后提出了适用于HTRB600级高强钢筋的高温下应力-应变曲线简化计算模型.     

废旧轮胎冲击粉碎及动力学模型的研究

常温下用自行开发的冲击式粉碎机对废旧轮胎进行了粉碎实验 ,并建立了相应的粉碎动力学模型 ,结果表明 :本装置常温下粉碎废旧轮胎确实可行 ,胶粉粒度分布范围广 ,产量高 ,该数学模型精度高 ,适用性强。     

国产结构用铝合金低温力学性能试验研究

为弥补目前国内外对结构用铝合金低温力学性能试验研究的不足,完成了国产结构用铝合金6082-T6、6N01-T6、6061-T6和6061-T4的低温恒温加载试验.试验测得4种牌号铝合金在-120～20℃下的抗拉极限强度、名义屈服强度、延伸率和断面收缩率等力学性能指标.试验结果表明,低温下铝合金会出现加工硬化现象,其抗拉极限强度和名义屈服强度均有所增加,但断后延伸率以及断面收缩率的变化规律不明显.通过试验数据拟合,得到4种牌号铝合金力学性能指标的低温提高系数的计算式.最后,将提高系数计算式与美国规范建议值进行比较,结果表明美国规范较为保守.     

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.