双向嵌套法及其在水力计算中的应用

在水力计算数值模拟中 ,计算的网格步长约束着计算精度和工作量 ,计算的范围、计算的网格尺度和计算量总是一对矛盾 .以平面二维水流运动方程为基础 ,兼顾到计算的网格步长、时间步长和计算的范围 ,应用了双向嵌套网格法 .工程算例表明 ,双向嵌套网格法具有减少计算工作量、提高模式计算精度的特点     

地下工程防水技术施工

就地下防水技术是地下工程的关键,介绍了地下工程防水技术的施工工艺,分析了如何检验防水材料施工合格的措施,提出了防水工程质量的保证措施,以防止建筑物的侵蚀,提高建筑物的耐久性和使用性。     

Calibration of focusing steps and image rotation of electron microscopes

Reflection electron microscopy (REM) is used to calibrate the focusing steps and rotation of electron microscopes. The calibration of focusing steps is done by the direct measurement of the shift on in-focus positions in the REM micrographs. Rotations between the diffraction patterns and images are calibrated in the usual way. By using the REM geometry, the reflection high energy electron diffraction (RHEED) patterns and REM images have no rotation symmetry, thus eliminating the 180° uncertainty.     

青海省都兰县丘吉沟铜矿激电中梯地球物理特征及找矿远景

青海省都兰县丘吉沟铜矿位于东昆仑造山带,柴达木盆地南缘,该区构造发育,岩浆活动频繁,成矿远景较好。由于丘吉沟铜矿为近年来新发现的矿体,对其开展的研究相对较少,矿区内找矿方向不明确,制约了矿山的找矿与生产工作。为了指明区内的找矿方向,此次通过对丘吉沟铜矿开展激电中梯地球物理勘探的研究,圈定成矿预测靶区,为矿山的下步工作指明方向。通过研究发现:激电异常形态受EW 与NE向断裂构造控制,与构造展布相一致,构造交汇部位或构造的中心部位是异常的高值区域,同时也是找矿的有利部位;此次研究共圈定3个物探异常区,其中Ⅰ级异常区2处,为QD02、QD03物探异常区;Ⅱ级异常区1处,为QD01物探异常区。研究结果将为区内找矿指明方向。     

维生素C生产技术

介绍了维生素C的性质、功能和用途。综述了维生素C生产技术的演变过程和发展趋势。着重探讨了微生物发酵法的生产工艺进展。介绍了二步发酵法与葡萄糖直接发酵法的研发现状，探讨了2—酮基—L—古龙酸的分离提取工艺。展望了我国维生素C生产技术的前景。指出，我国的维生素C生产应当重视工程菌的选育与发酵工艺的优化。     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Influence of ageing on the dynamic behaviour and the electrochemical characteristics of a 500 We PEMFC stack

In this study, a 500 We 19 cells Proton exchange membrane fuel cell (PEMFC) stack was aged for ∼1200 h and submitted to current steps between different operating levels. Using two different multi-channel data acquisition systems (one at 100 kHz and one at 1 Hz). the evolution with ageing of individual cells and full stack's short term (∼10 s) and medium term (∼4 min) dynamic performances was followed. Undershoots and overshoots behaviours were observed for respective current step-up and step-down. It appeared that, in studied operating conditions, the first time constant was related to the charge transfer at electrode/electrolyte interfaces. After the first “plateau”, the voltage evolution was explained by a membrane water content evolution.     

橡胶籽制油工艺与实践

橡胶籽是一种特殊的木本植物油料,通过对50 t/d橡胶籽制油工艺设计与实践,体会到橡胶籽制油的难点是湿橡胶籽的干燥,重点技术在脱除毛油中的粗橡胶和树脂,关键技术在含有较高不饱和脂肪酸的高酸值油精炼。制约橡胶籽制油规模的主要问题是橡胶籽的采收和湿橡胶籽的干燥处理。     

台阶规模边坡等效节理岩体三维网络模型的研究

众所周知,结构面的分布决定着岩体结构,且具有一定的随机性和统计规律。而节理作为一种重要的结构面,可以借助统计学原理,对边坡节理面的产状进行调查并分析,建立出等效节理面三维网络模型,为之后的岩体稳定性分析奠定良好的基础。通过VC++语言编程建立了等效节理岩体三维网络模型的专用程序3D-NET;同时利用OPEN GL三维可视化技术,增加了软件的图形处理功能。该软件在建立节理面三维网络模型之外,还为后续台阶坡面迹线网络的形成,及所有楔形体组合提供可靠的数据库,具有极其广泛的应用价值。     

用于工艺流程自动生成的排序算法

文章介绍了一种工艺流程的自动排序算法。该算法将器件的结构作为输入信息,利用工艺库,得到可制造出该器件的工艺路线。该算法可应用于VLI制造的工艺流程卡自动生成。