共查询到20条相似文献，搜索用时 140 毫秒
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熊红英 《中国石油大学胜利学院学报》2012,26(1):18-20
对高温高盐采油污水中氨氮难以通过生化脱氮去除的问题开展加碱曝气去除试验研究。通过不同水温、不同pH和曝气对比试验,提出在多股污水混合处理的污水厂,高温、高盐、高氨氮的污水在与其他污水混合前,利用污水水温高的特点,先投加石灰乳调节污水pH值,通过曝气除去部分氨氮后,再与其他污水混合进行后续处理的思路,以确保污水中氨氮得到有效去除。 相似文献
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《实验室研究与探索》2017,(9):145-148
按照实验设计,在一维有机玻璃模拟柱中填装一定高度固定粒径的石英砂,利用蠕动泵从柱体底部的进样口泵入一定浓度的甲苯溶液,静置一段时间后,在土柱底部利用空气泵曝气,在不同曝气时间下于柱体侧面的取样口取水样,分析甲苯的浓度变化。实验分组进行,主要考察了曝气、介质粒径和曝气方式对甲苯修复效果的影响。实验结果表明,对于0.25~0.5 mm的中砂介质,最佳曝气量为500 m L/min,曝气初期,距离曝气点最远的上部取样口处甲苯的相对浓度有短暂上升趋势,但随着曝气时间延长,所有取样口甲苯浓度均逐渐下降;相同曝气量条件下,介质粒径越大,修复效果越好;对于0.1~0.25 mm的细砂介质来说,间歇曝气方式优于连续曝气。以上实验结果表明,原位空气扰动修复技术能有效去除地下水中挥发性的甲苯,同时修复效果受曝气量、介质粒径和曝气方式影响。 相似文献
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曝气生物滤池反冲洗污泥的合理处置是其在推广应用中遇到的难题.反冲洗污泥对有机物和浊度有良好的去除效果,但对TP的去除效果甚微;将其与化学混凝剂复配可满足曝气生物滤池进水水质要求,且TP能维持在较低水平. 相似文献
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李旻 《江西电力职业技术学院学报》2021,34(9):7-9
在污水处理厂自动控制系统功能设计中,系统控制算法的先进性能为系统功能的详细设计提供有力支持,控制算法的优越性和可实现性对整个控制系统的运行至关重要.研究污水处理曝气过程,基于现实情况,提出合理的系统假设,并在此基础上,研究PID控制策略和模糊控制策略,分析两种策略的优缺点,提出基于PID的模糊控制策略作为污水曝气过程智能控制策略,并设计污水曝气系统控制器. 相似文献
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司德平 《中学物理教学参考》2002,31(4):64-64
道路标志牌是保证交通安全的重要措施 .夜晚乘车时会发现 ,道路标志牌具有良好的“醒目反光性能”,其夜间可视性源于道路标志牌上有一屋特殊的光学材料——回归反光膜 .现在它不仅被广泛用于路名牌、标志牌、标志杆等道路装置 ,还越来越多地应用于广告、装饰等行业 .回归反光膜由底膜层、反光层、粘合剂、玻璃微珠图 1层和透明保护层组成 (如图 1所示 ) .在粘合剂表面是单层排列的高透明度 ,高折射率 ,直径约为 10 μm的玻璃微珠 .底膜层由背胶和护纸构成 ,扯掉底膜上的护纸后 ,可用背胶贴在用普通材料 (如铝板 )制作的基板上 .反光层一般是… 相似文献
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在太阳能实际应用中,较低的光伏转换效率是主要技术瓶颈。本项目围绕如何直接改进太阳能电池板的面形结构和特性,实现一种更加简捷有效的提高光伏转换效率的技术途径。借助照相机在镜头中采用凸透镜和镀增透膜来增加聚光性能的思想,本方案采用玻璃微珠所具备的短焦距聚光能力增大太阳光的接收角,同时选用溶胶凝胶膜层增加光线透过性。实验验证了玻璃微珠和溶胶凝胶膜层对提高光伏转换效率的科学可行性。实验结果表明,在宽光谱卤素灯大角度（70°）入射条件下,光伏转换效率相对玻璃基板提高了15．73％,充分验证了设计方案的原理可行性。本方法主要基于对太阳能电池玻璃盖板的结构改进,不需额外增加光学系统,结构简单,易于实现,设计思想具有独立创新性,在提高太阳能的光伏转换效率方面有着重要应用价值和发展前景。 相似文献
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This work presents a new analytical method to analyze the influence of reaction piles on the test pile response in a static load test.In our method,the interactive effect between soil and pile is simulated using independent springs and the shear displacement method is adopted to analyze the influence of reaction piles on test pile response.Moreover,the influence of the sheltering effect between reaction piles and test pile on the test pile response is taken into account.Two cases are analyzed to verify the rationality and efficiency of the present method.This method can be easily extended to a nonlinear response of an influenced test pile embedded in a multilayered soil,and the validity is also demonstrated using centrifuge model tests and a computer program presented in the literature.The present analyses indicate that the proposed method will lead to an underestimation of the test pile settlement in a static load test if the influence of the presence of reaction piles on the test pile response is neglected. 相似文献
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为了测定耐碱玻璃纤维混凝土的抗折强度并分析其不确定度及纤维体积率对混凝土抗折强度的影响,选择耐碱玻璃纤维体积率为0%0,.6%,0.8%,1.0%的100 mm×100 mm×400 mm混凝土抗折试件进行试验。试验在MTS810材料试验机上进行,通过三分点加载测定其抗折强度,分析混凝土抗折强度试验中影响试验结果不确定的因素和来源,并按照JJF 1059-1999标准的要求,对合理玻璃纤维掺量试件的抗折强度的不确定度进行分析和评定。结果表明:耐碱玻璃纤维的掺入改变了混凝土抗折破坏形式,不同纤维体积率的混凝土抗折强度较普通混凝土依次提高了18.87%,21.64%,23.24%。综合考虑各方面因素确定耐碱玻璃纤维混凝土合理玻璃纤维掺量为0.6%;通过对试件抗折强度测定的不确定度评定,表明数学模型中自由度及测量的重复性是引入测量结果不确定度的主要因素;建议在进行同类试验时,试件尺寸应尽量大,从而可增大跨距,以减小剪力对测量结果的影响。 相似文献
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Research on the overload protection reliability of moulded case circuit-breakers and its test device 总被引：1，自引：0，他引：1
LI Kui LU Jian-guo WU Yi QIN Zhi-jun YAO Dong-mei 《浙江大学学报(A卷英文版)》2007,8(3):453-458
This paper analyzed the reliability and put forward the reliability index of overload protection for moulded case circuit breaker. The success rate was adopted as its reliability index of overload protection. Based on the reliability index and the reli- ability level, the reliability examination plan was analyzed and a test device for the overload protection of moulded case cir- cuit-breaker was developed. In the reliability test of overload protection, two power sources were used, which reduced the time of conversion and regulation between two different test currents in the overload protection test, which made the characteristic test more accurate. The test device was designed on the base of a Windows system, which made its operation simple and friendly. 相似文献
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为了提高web应用回归测试的效率,采用了控制流图和贪心算法.以页面为基本单位,通过构造web应用的控制流图,提出了一种基于控制流图的web应用回归测试的测试用例选择方法,该方法是一种安全的测试用例选择方法.在web应用回归测试的测试用例执行中,根据web应用中请求序列的特点,采用了最小化技术并考虑测试用例的优先级,提出了一种改进的贪心算法对测试执行进行了优化.实验结果表明,该方法有效地减少了需要重测的用例数并且提高了测试执行的效率. 相似文献
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Lisa Jane Bowers 《Open Learning》2019,34(1):6-18
ABSTRACTMachine haptics has been shown to assist and enhance human–computer interactions. Research from previous studies in the field of haptics has focused on developing a user’s sense of realism of touch when using a haptic device. This paper examines the use of haptics for education, specifically for creative online education. The paper is presented in two parts. First, a review of literature was conducted and used to aid the rationale and underpin the design of a pilot test. Second, a pilot test was designed using a single-point kinaesthetic haptic device with a haptic rendered interface, to support the assembly of a virtual design prototype. The pilot test proved to be extremely valuable in creating and developing a rich virtual environment for non-sighted and sighted participants to use. The results from the initial pilot test showed that although users were positive about their experience of using the haptic device, there were improvements to be made to the interface to enhance the user experience in the next phase of testing. 相似文献
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张晓君 《中国现代教育装备》2014,(15):45-46
针对实验室现有非金属声波检测仪在使用中存在的问题,研究了实现岩石声波数据高速传输的方法,探讨了实现对岩石试样进行多点声波测试所需装置的设计思路,结果表明,该方法与装置可实现对围岩或岩石声波测试实验数据的高速传输,并可对围岩或岩石多点位的声波进行监测。 相似文献
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许进 《广东广播电视大学学报》2008,17(4):92-96
为探讨CO2水玻璃砂用改性水玻璃对不同硬化方法的适应性,分别对CO2／酯法、CO2／热空气法和CO2／烘干法进行了研究,获取了不同硬化方法的有关工艺参数。结果表明,CO2／酯法工艺能更好地发挥改性水玻璃的粘结效率,提高粘结强度,但型砂的可使用时间缩短,适用于气温较低冬季;CO2／热空气法使型、芯获得较高的强度,硬化所需时闻缩短,能改善型、芯的存放性,兼具热空气法和CO2法的优点;CO2／烘干法可获得较高的粘结强度。 相似文献
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张明霞 《实验室研究与探索》2012,31(3):9-11,14
在牛顿环干涉实验中,若在平凸透镜的凸面与平玻璃板间加入少许液体,可将液体膜局域等效于液体劈尖,则液体膜可看成是沿平凸透镜的凸面与平玻璃板接触点向外的径向线性增加的液体劈尖,利用液体劈尖的等厚干涉理论可推导出平凸透镜的曲率半径与光波波长间的关系式,进而得到液体折射率与空气膜及液体膜产生的干涉圆环直径间的关系式。利用此关系式可知,只要不改变实验装置,在未知凸透镜曲率半径和光波波长的情况下,分别测出在同一牛顿环装置下液体膜和空气膜的任意相邻干涉圆环的直径,即可方便地测出液体的折射率。 相似文献
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Lorrie A. Shepard 《Assessment in Education: Principles, Policy & Practice》2016,23(2):268-280
The AERA, APA, NCME Standards define validity as ‘the degree to which evidence and theory support the interpretations of test scores for proposed uses of tests’. A century of disagreement about validity does not mean that there has not been substantial progress. This consensus definition brings together interpretations and use so that it is one idea, not a sequence of steps. Just as test design is framed by a particular context of use, so too must validation research focus on the adequacy of tests for specific purposes. The consensus definition also carries forward major reforms in validity theory begun in the 1970s that rejected separate types of validity evidence for different types of tests, e.g. content validity for achievement tests and predictive correlations for employment tests. When the current definition refers to both ‘evidence and theory’ the Standards are requiring not just that a test be well designed based on theory but that evidence be collected to verify that the test device is working as intended. Having taught policy-makers, citizens, and the courts to use the word validity, especially in high-stakes applications, we cannot after the fact substitute a more limited, technical definition of validity. An official definition provides clarity even for those who disagree, because it serves as a touchstone and obliges them to acknowledge when they are departing from it. 相似文献