小议合同管理

介绍了平行式和总分式两种合同网络架构方式,并对两种方式的优缺点进行了分析,阐述了合同类型及单价合同的管理问题,指出合同管理对于工程管理的重要性,对提高工程质量具有重要意义。     

硅钾基防塌钻井液在江汉松滋油田的应用研究

根据江汉松滋油田地层泥页岩的矿物组成、微观结构及理化性能资料．研究出了适于该油田的硅钾基防塌钻井液体系的基本配方．评价了其防塌性能、抗钻屑污染能力及抗温能力．探讨了其防塌机理。现场应用表明．该体系维护容易．防塌效果明显。     

The impact of the Hebbian learning rule on research in behavioural neuroscience.

Hebb's principal theoretical propositions, the cell assembly and the nature of synaptic change, were generated at a time when the focus of work in behavioural neuroscience was directed at understanding issues such as the principles governing the behaviour of animals in neuropsychological studies of learning and memory and the role of drives in the control of behaviours like sex and feeding and drinking. It was not until attention shifted to understanding the neural underpinnings of learning and memory that Hebb's propositions had an impact on behavioural neuroscience as they provided a simple, and testable, mechanism for synaptic plasticity observed both in learning and in other forms of experience-dependent neural change. But much of the field remains interested in other issues such as sensation and perception, motivation, attention, and so on, and to date, Hebb's propositions have had little impact. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

FEM model of the ohmic resistance of IP-SOFCs

In the present work, the ohmic resistance of an integrated planar-SOFC (IP-SOFC) has been evaluated by developing a model whose equations have been solved numerically through an FEM method. The model allows to estimate the distribution of voltage and current density in the cell. A comparison between simulated and experimental data of area specific resistance is reported, which shows satisfactory agreement. The mathematical model has also been used to carry out some parametric studies for optimisation purposes. Indeed, a reduction in cell pitch length and an increase in electrode thickness are predicted to lead to a reduction in ohmic losses in IP-SOFCs.     

溶胶-凝胶法制备纳米氧化锡及其性能表征

以SnCl4·5H2O为原料,采用溶胶-凝胶法制备了纳米SnO2粒子,研究了焙烧温度、碱的种类及反应物浓度对纳米SnO2粒子大小和分散状态的影响。采用XRD、TEM、ED等技术对SnO2纳米粒子的性能进行了表征。实验结果表明:用氨水和尿素作为沉淀剂,控制反应结束时pH值为7,在600℃焙烧,制备得到粒子尺寸约为15nm、分散性良好的纳米SnO2粒子。     

不锈钢冶炼过程中相关热力学问题的解析(Ⅰ)--原料预处理时的热力学问题

针对“电弧炉 多功能转炉 VOD”三步法不锈钢冶炼工艺，以脱磷为主线，从冶金热力学的角度对流程中涉及的几个重要工艺环节的可行性(包括电弧炉去硅保铬、铁水包同时脱磷脱硫等问题)进行了理论分析和计算。在此基础上，提出了强化冶炼和脱磷的工艺措施，从而为不锈钢冶炼全流程控制磷及优化脱磷工艺提供了理论依据。     

物质平衡法测油井液面

物质平衡法通过测试环空中的气体排量折算出真实的环空液面，可以克服双频道回声仪所遇到的困难，为分析泵效、折算地层压力及区块注水补充地层能量提供依据。中原油田采油二厂研制的拟液面测试仪既能用于有泡沫段的油井，又可用于无泡沫段的油井，对于井深超过2500m的油井更适宜。     

一种跟踪电网频率的新方法

基于正交变换,提出了一种新的电网频率跟踪方法.针对两种模型进行仿真,表明该方法能够较为精确与快速地跟踪电网频率,尤其针对突变频率的信号,具有较好的跟踪效果;同时算法克服了同步采样条件的限制,通过迭代,在不同初始频率下均具有较好的收敛性.     

高档工作面顶板管理的几点做法

介绍了9号、10号、11号煤层开采中顶板管理的具体做法，对特殊时期的初采初放和末采回收也做了阐述，并对特殊地质条件下的顶板管理提出了可行的方法。     

用气相色谱测定液氧中乙炔及其他碳氢化合物的含量

利用气相色谱浓缩法和气相色谱直接法测定液氧中乙炔及其他碳氢化合物含量。通过比较。用气相色谱直接法测定，方法简便，快捷，准确。