基于颗粒流的U型通风下采空区发火过程模拟研究

为研究在U型通风下工作面正常推进时遗煤自然发火特点及过程,考虑到遗煤由于采动造成的松散多孔结构有利于O2与煤的接触反应,使用基于颗粒流的PFC3D作为模拟工具,模拟了自然发火过程中遗煤的温度分布及能量迁移过程。使用极小颗粒模拟O2的流动及其与煤的反应,并通过FISH实现该过程。模拟研究表明:遗煤自然发火过程主要可分为3个阶段;遗煤自然发火过程中升温区的变化与O2流动有较大关系。     

2,2-Dicyanovinyl-end-capped oligothiophenes as electron acceptor in solution processed bulk-heterojunction organic solar cells

Three 2,2-dicyanovinyl (DCV) end-capped A-π-D-π-A type oligothiophenes (DCV-OTs) containing dithieno[3,2-b:2′,3′-d]silole (DTSi), cyclopenta[1,2-b:3,4-b′]dithiophene (DTCP) or dithieno[3,2-b:2′,3′-d]pyrrole (DTPy) unit as the central donor part, mono-thiophene as the π-conjugation bridge were synthesized. The absorption spectroscopies, cyclic voltammetry of these compounds were characterized. Results showed that all these compounds have intensive absorption band over 500–680 nm with a LUMO energy level around −3.80 eV, which is slightly higher than that of [6,6]phenyl-C₆₁-butyric acid methyl ester (PC₆₁BM, E_LUMO = −4.01 eV), but lower than that of poly(3-hexylthiophene) (P3HT, E_LUMO = −2.91 eV). Solution processed bulk heterojunction “all-thiophene” solar cells using P3HT as electron donor and the above mentioned oligothiophenes as electron acceptor were fabricated and tested. The highest power conversion efficiency (PCE) of 1.31% was achieved for DTSi-cored compound DTSi(THDCV)₂, whereas PTB7:DTSi(THDCV)₂ based device showed slightly higher PCE of 1.56%. Electron mobilities of these three compounds were measured to be around 10⁻⁵ cm² V⁻¹ s⁻¹ by space charge limited current method, which is much lower than that of PC₆₁BM, and was considered as one of the reason for the low photovoltaic performance.     

支撑系统对低音扬声器特性的影响

通过对比测试低音扬声器的定心支片和复合边这两个起支撑作用部件受力位移的非线性特性,分析、解释了扬声器的相关特性与它们之间的联系,同时为解决扬声器的可靠性问题和改善失真问题提供相关的实践经验.     

基于Matlab的信号与系统实验平台设计

信号与系统课程实验内容繁杂,为了克服传统硬件实验系统的局限性,利用Matlab软件提供的图形用户界面（GUI）设计了信号与系统仿真实验平台。该实验平台由一个主界面和若干子界面构成,包括信号卷积、傅里叶变换、拉普拉斯变换、Z变换、系统的频率响应等实验项目。每个实验界面都可以由用户设定和修改仿真参数,实时显示仿真结果。该平台将抽象的理论教学转化为生动的仿真实验,从而提高学生学习兴趣,加深对教学内容的理解。     

槽波地震“透射-反射”联合法在回采工作面地质构造探测中的应用

煤矿工作面回采过程中无计划揭露地质构造将造成人员伤亡和财产损失,严重影响煤矿安全生产,为提前探明其赋存规律,针对典型回采工作面,采用槽波地震“透射-反射”联合法进行地质构造精细化探测。结果表明:槽波地震透射法探测对采面内陷落柱的反应良好,可以高精度控制陷落柱的影响区域,且偏差小于20 m;槽波地震反射法探测对采面内走向型断层的反应良好,可以找到采面内断距大于1.5 m的近走向型断层的发育位置及延伸长度;综合利用槽波地震“透射-反射”联合法进行采面地质构造精细化探测,可提升探测准确率,对于直径30 m以上陷落柱和断距大于1.5 m近走向断层的探测准确率可提高至80%以上。     

大民屯凹陷沙四段湖相页岩油地震预测关键技术与应用

大民屯凹陷沙四段湖相页岩油地层岩性复杂、有效厚度薄、储层变化快,利用常规的叠后地震方法预测“甜点”的精度较低,制约了页岩油资源的经济有效动用。针对研究区页岩油地质特征,以提高“甜点”预测精度为导向,探索形成了地震资料优化处理、叠前弹性参数联合反演、有效裂缝预测等多项关键技术。在地震资料处理方面,形成了以“全程Q补偿”为核心的宽频保幅处理技术思路,道集质量和频带宽度得到有效改善,提高了地震解决复杂地质问题的能力;在储层预测方面,综合应用叠前弹性参数联合反演技术和AVOZF反演技术,实现了岩性、脆性、TOC含量及有效裂缝等地质参数的高分辨率预测,明确了大民屯沙四段页岩油“甜点”分布的有利区,落实Ⅰ类、Ⅱ类“甜点”面积约为143 km²。现场实践结果表明,新钻的水平井地质评价结果与储层预测吻合程度高,储层的钻遇率达66.4%。研究结果为大民屯凹陷页岩油资源的勘探开发提供了有力技术支撑。     

Symbols of terror: The witch/vampire, the spider, and the shark.

Three symbols of terror are examined as representations of preoedipal conflicts that intrude upon conscious awareness and. interfere with current functioning. To understand each of these symbols and their origins in a state of chronic terror, it is necessary to understand the complete life history of the patient. All three symbols--the witch/vampire, the spider, and the shark--relate to earliest experiences within the parent/infant dyad. We suggest that although all three symbols relate to the dimension of oral aggression, they can be placed conceptually along a continuum of distance from the quality of humanness. Clinical examples are given to illustrate the use of these symbols by patients in treatment and their theoretical implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

多晶硅TFT有源层晶粒间界的研究

由于多晶硅薄膜晶粒间界存在大量的悬挂键与缺陷，形成带隙能态，从而导致在有源层中形成载流子陷阱和杂质分凝，本文从微观方面解释悬挂键形成带隙能态的原因极其影响，并给出降低带隙密度的方法-氢化。     

Methodology for security analysis of data-processing systems

Use of the logic programming language PROLOG assists in tracking functional relationships through complex networks to ensure that all products receive a security classification consistent with the operative security model. The language also permits computing work factors for data products. In some cases, these work factors may modify the levels of protection required.     

Information as a corporate asset

The author explains the need for and necessity of information for running a complex multinational company like Philips. He gives a short overview of the organization and structure of Philips, employing almost 400,000 people, and its world-wide activities. He deals with specific aspects and problems regarding the production, storage and distribution of a large range of Philips products, i.e., how this huge task was tackled in the early EDP days, and what difficulties and troubles had to be overcome. Gradually a new generation of managers has developed who are able to handle the possibilities of computers and automated information systems.However, the multinational Philips covers thousands of separate units which cannot operate on their own. For business-information exchange they have to communicate in a well-defined language based on stadardized data elements. Data-bases, in the future interconnected by a world-wide communications network, contain data that represent valuable and indispensible information for the Philips company: a real corporate asset.With some reserve the writer dares to make predictions about the future of automation, yet mentions some clear trends and draws interesting conclusions.