ZnS:Cu的电致发光特性

为了以ZnS为基质材料获得蓝色电致发光 ,烧结了ZnS :Cu ,进而制备了薄膜电致发光显示器件 .测量了其电致发光光谱 ,发现它具有 4个峰 .研究了发光强度随电压、频率变化的规律 .结果表明 ,利用ZnS :Cu可获得蓝色电致发光 .     

pH值对电致发光粉表面包覆SiO_2膜的影响

采用Na_2SiO_3水解法,在ZnS:Cu电致发光粉表面包覆SiO_2膜层,并主要分析了包SiO_2膜时,pH值对包覆膜致密性的影响。发现电致发光粉在pH=9.5的Na_2SiO_3溶液中预分散条件下,陈化至8.5,易于形成均匀致密的SiO_2膜层。因此,电致发光粉的老化性能得到一定程度的改善,延缓了它的老化。     

温度对电致发光粉表面包覆SiO_2膜特性的影响

采用化学气相沉积法,以硅酸乙酯和氧气作为前驱体在ZnS:Cu电致发光粉表面包覆SiO2薄膜,并对样品进行了能量色散X射线分析,AgNO3抗腐蚀,发光亮度和光谱等测试.结果证实当温度为500℃时,包膜样品具有良好的防潮抗腐蚀性能,材料发光寿命得到明显改善,包膜样品的发光光谱峰没有产生大的移动.     

水热法制备ZnS:Mn纳米发光粉

采用水热法,以十六烷三甲基溴化氨(C16TAB)作为表面活性剂,在填充度为75%和温度180℃的条件下,制备了ZnS:Mn的纳米发光粉体.利用激发光谱、发射光谱和透射电子显微镜对其光学特性和形貌进行了研究.实验发现,与未进行表面修饰的ZnS:Mn纳米粒子相比,ZnS:Mn纳米颗粒发光亮度增加数倍,而且随着表面活性剂浓度的增加,ZnS:Mn发光强度显著增强.当质量比m(C16TAB)∶m(Zn)=1∶5时,发光强度达到最大,粒径分布均匀,呈球形,平均粒度为50 nm.     

激活剂对粉末电致发光材料发光性能的影响

采用掺杂2种激活剂制备了粉末电致发光材料ZnS:Cu,Au,发现激活剂Cu+,Au+的掺杂量对材料亮度有较大影响.当掺入激活剂Au+与基质ZnS的质量比为0.05%,而掺入Cu+的量比达到0.29%时,得到了在400 Hz,150 V激发下,亮度可达105 cd/m2的绿色电致发光材料.通过光谱分析发现,掺杂后并没有改变发光材料的颜色.同时,用扫描电子显微镜(SEM)对ZnS:Cu,Au颗粒进行了尺寸和形貌表征.     

Cu~+对ZnS:Cu电致发光材料光致发光光谱的影响

以ZnS为基质材料,在其中掺入Cu+,使其质量比分别为0.05%,0.10%,0.15%,0.20%,0.25%,制得5个不同的ZnS:Cu电致发光材料样品.通过对样品材料光致发光光谱的分析和电致发光亮度的测量,发现随着Cu+含量的增加,样品材料的光致发光光谱波长由480nm逐渐变为520nm,即由蓝色变为绿色.当Cu+的质量比高于0.15%,虽然发光中心数目增加,但光致发光光谱的强度降低,电致发光亮度减弱.得出结论:Cu+与ZnS的质量比为0.15%时,ZnS:Cu电致发光材料的光致发光光谱峰值最大,电致发光亮度最高.     

Cf表面修饰对C_(f-包覆Cu)/Mg_2Si-Al_2O_3复合材料组织与性能的影响

用电化学的方法对碳纤维表面进行包覆Cu修饰,并采用机械合金化+热压烧结制备C_(f-包覆Cu)/Mg_2Si-Al_2O_3复合材料,研究C_(f-包覆Cu)质量分数对该复合材料组织、密度、强度及导电率的影响.结果表明:电化学包覆Cu修饰的Cf加入后并未生成新相,而是均匀地分布在复合材料中,与基体之间界面平直,结合良好.Al_2O_3主要分布在Mg_2Si基体的晶界处,部分分布在C_(f-包覆Cu)周围.随着C_(f-包覆Cu)质量分数的增加,致密度有所降低,复合材料电导率、硬度、抗压强度和抗弯强度均先增大后降小,在1.5%时取得最大值.复合材料的强化主要是纤维拔出.     

ZnS:TmF3薄膜电致发光特性的研究

为了提高蓝色薄膜电致发光器件(TFEL)的发光亮度,自行配制了氟化铥(TmF3),并制备了以ZnS:TmF3为发光层的薄膜电致发光器件,研究了TmF3的掺杂浓度对ZnS:TmF3 发光器件发光特性的影响.实验结果显示,当掺杂浓度为1.2%mol时,发光亮度最强.     

硅铝包覆钛白粉水悬浮液pH值调控规律

研究了钛白粉经过氧化硅、氧化铝包膜后的水悬浮液pH值和颗粒表面电位特性的变化。实验获得连续、均匀、致密的无机氧化物膜状包覆,膜层厚度随包覆量增加而增加。根据国家标准GB/T1706—2006中的测定方法,将包膜后钛白粉制成质量分数为10%的悬浮液,检测悬浮液pH值随包覆量的变化。结果表明:钛白粉经氧化硅和氧化铝表面包膜处理后,水悬浮液pH值偏离中性;包氧化硅后钛白粉悬浮液呈碱性,随包覆量增加,pH值增高直至pH9.7;包氧化铝后钛白粉悬浮液呈酸性,随包覆量增加,pH值降低直至pH4.4。颗粒表面包覆量对颗粒表面的ζ电位的影响与pH值相似。通过对包硅产品进行微量包铝、或对包铝产品进行微量包硅能够有效调控最终包覆产品水悬浮液的pH值。     

铜溅射时间对Cu_2ZnSnS_4薄膜性能的影响

采用磁控溅射方法制备铜溅射时间分别为1.5 h和2 h的Cu/Sn/ZnS前驱体薄膜,然后利用双温区高温管式炉对两种薄膜进行硫化处理制备Cu_2ZnSnS_4.利用X射线衍射仪、拉曼光谱仪、扫描电子显微镜、能谱分析仪和紫外—可见分光光度计对薄膜的结构、表面形貌、化学成分和光学性能进行表征.结果表明:溅射1.5 h的Cu制备的薄膜表面存在大量杂质,表面很不平整;溅射2 h的Cu的薄膜表面呈现均匀致密的颗粒状薄膜,且具有更大的晶粒尺寸;溅射2 h的Cu的薄膜为单一CZTS相,其化学成分原子比更接近Cu_2ZnSnS_4化学计量比.     

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…     

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.     

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.