1TB-2型数控系统在CK0628车床数控改造中的应用研究

将KND 1TB-2型数控系统应用在CK0628车床数控改造中,实现了CK0628车床的数控加工,并且使得改造后的数控机床加工精度比原机床提高一个等级。数控改造主要包括机床机械部分改造以及伺服驱动部分改造。     

Enhanced oil recovery from carbonate reservoirs by spontaneous imbibition of low salinity water

An experimental study was performed to investigate the impact of low salinity water on wettability alteration in carbonate core samples from southern Iranian reservoirs by spontaneous imbibition. In this paper, the effect of temperature, salinity, permeability and connate water were investigated by comparing the produced hydrocarbon curves. Contact angle measurements were taken to confirm the alteration of surface wettability of porous media. Oil recovery was enhanced by increasing the dilution ratio of sea water, and there existed an optimum dilution ratio at which the highest oil recovery was achieved. In addition, temperature had a very significant impact on oil recovery from carbonate rocks. Furthermore, oil recovery from a spontaneous imbibition process was directly proportional to the permeability of the core samples. The presence of connate water saturation inside the porous media facilitated oil production significantly. Also, the oil recovery from porous media was highly dependent on ion repulsion/attraction activity of the rock surface which directly impacts on the wettability conditions. Finally, the highest ion attraction percentage was measured for sodium while there was no significant change in pH for all experiments.     

环境流计算新方法:水文变化的生态限度法

水文变化的生态限度框架(ELOHA)是环境流理论最新成果。ELOHA要求对河流按照水文情势特征进行分类,相同类型河流的水文—生态关系具有相似性。ELOHA还要求对开发前后水文情势变化进行分析,计算现状水文条件与基准水文条件的偏离程度。ELOHA提出了水文情势变化预期生态响应的若干假定,总结了一套为建立水文—生态关系采用的生态指标。在建立大型水文和生物数据库的基础上,运用统计学方法拟合水文—生态函数关系。最后,各利益相关者对水文变化引起的生态风险进行评估,认定可以接受的生态风险水平,再依据水文—生态曲线,确定环境流标准。     

火灾中衬砌混凝土损伤的微观特征

铜-黄公路涵洞衬砌混凝土在火灾中的损伤特征显示了变色、裂隙发育和逐层剥落的宏观特征.在显微尺度下受损混凝土裂隙的类型及其扩展规律和矿物相变显示了,中等损伤程度下裂隙的扩展和爆裂作用的叠加是衬砌混凝土发生多层剥落的重要原因;受火混凝土颜色的变化主要与矿物相变和微裂隙的形成有关.     

甘肃省肃北县二段井地区遥感地质特征及金多金属找矿预测

甘肃省肃北县二段井地区属于北山造山带南带拾金坡-金场沟金、铜、铁和铅锌、银、稀有金属成矿带,具有良好的成矿条件和找矿潜力.该文利用日本ALOS遥感数据,完成遥感地质解译工作,采用美国Land-sat 8 OLI数据完成矿化蚀变信息的提取工作,并结合已有的地质矿产及物化探资料,对区内的成矿地质条件及找矿远景进行了分析预测...     

谈2013建设工程工程量清单计价规范的变化

介绍了2013《建设工程工程量清单计价规范》的出台背景与形式,对风险分担、招标控制价、投标报价、签约合同价、竣工结算价五个方面内容作了详细研究,指出新规范使中国工程造价进入了全过程精细化管理的新时代。     

琅琊山抽水蓄能电站地下厂房蚀变岩带基础处理

琅琊山抽水蓄能电站地下厂房地基陡倾角薄层灰岩与花岗闪长蚀变岩带相间发育,其中蚀变岩带随机分布,遇水崩解泥化,强度较低。针对灰岩与蚀变岩相间的不均一岩性地基,采用整体刚性箱型基础结构,成功解决了地下厂房基础承载能力和不均匀沉降变形问题,为机组长期安全稳定运行奠定了基础,取得了良好的经济效益和社会效益。     

Radiometric correction of multi-temporal Landsat data for characterization of early successional forest patterns in western Oregon

Detecting and characterizing continuous changes in early forest succession using multi-temporal satellite imagery requires atmospheric correction procedures that are both operationally reliable, and that result in comparable units (e.g., surface reflectance). This paper presents a comparison of five atmospheric correction methods (2 relative, 3 absolute) used to correct a nearly continuous 20-year Landsat TM/ETM+ image data set (19-images) covering western Oregon (path/row 46/29). In theory, full absolute correction of individual images in a time-series should effectively minimize atmospheric effects resulting in a series of images that appears more similar in spectral response than the same set of uncorrected images. Contradicting this theory, evidence is presented that demonstrates how absolute correction methods such as Second Simulation of the Satellite Signal in the Solar Spectrum (6 s), Modified Dense Dark Vegetation (MDDV), and Dark Object Subtraction (DOS) actually make images in a time-series somewhat less spectrally similar to one another. Since the development of meaningful spectral reflectance trajectories is more dependant on consistent measurement of surface reflectance rather than on accurate estimation of true surface reflectance, correction using image pairs is also tested. The relative methods tested are variants of an approach referred to as “absolute-normalization”, which matches images in a time-series to an atmospherically corrected reference image using pseudo-invariant features and reduced major axis (RMA) regression. An advantage of “absolute-normalization” is that all images in the time-series are converted to units of surface reflectance while simultaneously being corrected for atmospheric effects. Of the two relative correction methods used for “absolute-normalization”, the first employed an automated ordination algorithm called multivariate alteration detection (MAD) to statistically locate pseudo-invariant pixels between each subject and reference image, while the second used analyst selected pseudo-invariant features (PIF) common to the entire image set. Overall, relative correction employed in the “absolute-normalization” context produced the most consistent temporal reflectance response, with the automated MAD algorithm performing equally as well as the handpicked PIFs. Although both relative methods performed nearly equally in terms of observed errors, several reasons emerged for preferring the MAD algorithm. The paper concludes by demonstrating how “absolute-normalization” improves (i.e., reduces scatter in) spectral reflectance trajectory models used for characterizing patterns of early forest succession.     

浅述管道不停输开孔封堵技术

随着工业的发展,管道不停输开孔封堵技术在管线改造项目中得到越来越广泛地运用。文章结合实际工程简要介绍了管道不停输开工封堵技术的设备、原理和流程,并提出应注意的问题。     

手动经济型数控刀架的原理与设计

手动经济型数控刀架采用类似于仿行刀架的布局形式，提出了一种新的数控插补方法，通过对单坐标的控制实现了两坐标联动的功能。