地源热泵的设计浅析

对浅层地热能资源的状况进行了分析及评估,进行了负荷计算,介绍了地源热泵的设计,提出了设计中应注意的问题,以帮助工程技术人员真正理解地源热泵系统的设计理念,从而正确设计和使用地源热泵系统。     

防爆技术在气动葫芦产品上的应用

气动葫芦等非电气设备应用在爆炸性环境时，在正常工作过程中会因机械摩擦和碰撞产生热表面、明火、灼热气体／液体、机械火花、绝热压缩、振动波、化学反应放热、铝热反应、粉尘自燃、电弧和静电放电等点燃源，形成爆炸危险。这些设备可以通过限制运行速度、润滑、限定材质、采用隔爆外壳等措施来达到防燃要求。     

A mesh adaptation framework for dealing with large deforming meshes

In this paper, we identify and propose solutions for several issues encountered when designing a mesh adaptation package, such as mesh‐to‐mesh projections and mesh database design, and we describe an algorithm to integrate a mesh adaptation procedure in a physics solver. The open‐source MAdLib package is presented as an example of such a mesh adaptation library. A new technique combining global node repositioning and mesh optimization in order to perform arbitrarily large deformations is also proposed. We then present several test cases to evaluate the performances of the proposed techniques and to show their applicability to fluid–structure interaction problems with arbitrarily large deformations. Copyright © 2009 John Wiley & Sons, Ltd.     

An error control approach to tool path adjustment conforming to the deformation of thin-walled workpiece

Producing an accurate part mainly depends on the position and orientation of the cutting tool with respect to the workpiece which is mainly influenced by the rigid body motion of the workpiece and the elastic deformation of workpiece-fixture-cutter system. For the purpose of minimizing the machining error, a new modification strategy of the nominal tool path is not that directly compensate the control commands of the machine tools, but that modify the cutter location source file (CLSF) from the computer aided manufacturing (CAM) system by means of the proposed modification model on the basis of the prediction deviation, namely, the deviation of the cutting tool relative to the workpiece in computer numerical control (CNC) machining operation. Therefore, it is not only simpler, but also easier implemented by common manufacturing engineer. The effectiveness of the proposed strategy is verified by a machining example.     

受控源“电阻性”和“有源性”的研究

首先对受控源的电阻性和有源性进行了分析,然后比较完整系统地讨论了受控源的双重特性在线性时不变含受控源网络中的作用,并通过实例说明了受控源的双重特性在电路等效变换以及叠加定理中的具体的应用。     

用于荧光灯管的全新第四代电子源（二）

在荧光灯（FL）管中,人们凭借经验发现了一种全新的电子源,它是高温氩晕空间（HTACS）。HTACS在带有微小BaO颗粒钨丝线圈的受热裸金属斑点上形成,在氩气体空间中,取自处于负电势阴极电极上HTACS的电子,向处于正电势阳极电极上的HTACS运动。在点亮FL管中,来自HTACS的流光电子在所运行ac电压处于正电势期间...     

Characterizing multiple memory deficits and their relation to everyday functioning in individuals with mild cognitive impairment.

The authors evaluated multiple memory processes and explored their contributions to everyday functional limitations in persons with mild cognitive impairment (MCI). Participants included individuals with amnestic MCI, nonamnestic MCI, and healthy older adults. As expected, the amnestic MCI group performed more poorly than the control and nonamnestic MCI groups on a content memory measure. Both MCI groups, however, performed more poorly than controls on the noncontent memory measures of prospective memory, temporal order memory, and source memory. Informants also reported that the MCI groups were experiencing greater difficulty than controls completing instrumental activities of daily living (IADLs). Noncontent memory measures were found to make an independent contribution to IADL performances over and above that of content memory. These findings demonstrate that impairments in memory beyond the traditionally assessed content memory are present in individuals with amnestic MCI and with nonamnestic MCI. The results further show that these noncontent memory processes, which have been linked with executive functioning, play a role in supporting IADLs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

湖水源热泵系统排热工况下散点排水对湖体温度场的影响

采用流体计算软件建立三维湖体模型，模拟设计日下湖体自然水温，用实测水温进行修正作为初始条件；根据别墅群全年逐时负荷的模拟结果，采用动态取排水温和水量作为边界条件；以典型气象年数据为基础，通过用户自定函数输入水面换热边界；分别对某别墅群水库水源热泵系统的排放水管网采用与雨水排水管网相结合的散点排水以及采用传统的集中排水方式进行了动态数值模拟，得到供冷季逐时排热工况下湖体温度场的分布情况，分散排水优势明显。分析模拟结果表明：集中排水方案水体周温升0.33 ℃，分散排水方案水体周温升0.16 ℃；水体水道狭长体积有限的区域在连续排水的情况下，有明显热累积现象。连续运行条件下，散点排水取水口水温的模拟结果表明：7~10月，位于常年水位4.6 m水深下的取水口取水温度在27~23.5 ℃之间，可实现热泵系统高效运行。     

浅谈土壤源热泵系统的发展及其应用

概述了土壤源热泵系统的特点，阐述了土壤源热泵技术在国内外的发展、研究现状，最后介绍了土壤源热泵技术在发展中面临的问题及在制冷空调中的广阔应用前景。     

WDM-PON光接入网技术研究

介绍了WDM-PON系统的基本原理及技术优势,重点分析和探讨了其中所涉及到的关键技术,最后分析了WDM-PON的应用前景。