Improvement of rainwater infiltration and storage capacity by an enhanced seepage well: From laboratory investigation to HYDRUS-2D numerical analysis

Seepage well is an emerging Low Impact Development (LID) technology that can effectively control the storm runoff. However, its rainwater infiltration rate and storage capacity still require further enhancement. By setting a horizontal infiltration structure at the bottom of conventional rainwater seepage well (CSW), an enhanced seepage well (ESW) was proposed in this study, and its infiltration performances compared with the permeable pavement (PP) and the CSW were systemically investigated using static infiltration experiment and HYDRUS-2D simulation. The results showed that the infiltration efficiency of ESW was significantly higher than that of PP and CSW, and the process of water infiltrated through soil mainly controlled the macroscopic infiltration rate. The Nash-Sutcliff Efficient (NSE) index was used to evaluate the accuracy and reliability of the HYDRUS-2D model, and the results of NSE values greater than 0.75 (varied between 0.75 and 0.91) confirmed the applicability of HYDRUS-2D to describe correctly the hydraulic behavior of the ESW system. Simulation infiltration tests showed that the ESW performed a higher average infiltration rate and fewer total runoff volume than the CSW, indicating the effectively enhancement of the infiltration and water retention capacity of ESW, especially under heavy rainfall intensities. Additionally, the ESW system exhibited an excellent runoff-control and rainwater retention capacity in an actual rainfall scenario.     

气动锚杆钻机冲击频率测量仪的设计

针对气动锚杆钻机冲击频率不易测量的问题,提出了一种新型气动锚杆钻机冲击频率测量仪的设计方案。该测量仪采用压力传感器采集钻机冲击信号,采用电压比较器和单稳态触发器处理冲击信号并输入到单片机,由单片机计算出钻机冲击频率。实际应用表明,该测量仪可准确、方便地测量出钻机冲击频率。     

More on Goddard and the Kallikak family photographs.

Discusses retouching of the Kallikak family photographs in H. H. Goddard's (1912) study of mental retardation and heredity, with reference to analyses by R. E. Fancher (see record 1987-31600-001) and S. J. Gould (1981), and concurs with Fancher that the retouching was probably not done for deceitful purposes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adverse impact: Is it a viable concept?

It appears that those federal agencies responsible for enforcement persist in the belief that a given test score can mean one thing in one subgroup and something else in another and/or that inferences from a set of test scores can be valid for one subgroup but not for another. First surfacing in early agency regulations in connection with the now discontinued "differential validity" requirement, the belief still manifests itself in the concepts of "unfairness" and "adverse impact." Furthermore, the determination of the presence or absence of adverse impact on the basis of the impact ratio involves numerous statistical and measurement issues. Use of the impact ratio to establish the prosecutorial posture of an enforcement agency is clearly flawed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

人工智能对国内劳动就业影响研究综述

利用citespace关键词共现分析方法,梳理了1980年以来人工智能对劳动就业影响的国内相关文献,发现目前的研究议题主要包括人工智能影响就业的机制、人工智能对就业规模的影响、人工智能对收入分配的影响、人工智能对就业形态的影响、人工智能对劳动过程与劳动关系的影响. 总体来看,目前的研究主要集中在与劳动力市场相关的议题; 理论性的论述占大多数,而具有说服力的实证研究较少; 宏观性的研究较多,深入企业与生产现场考察的微观研究较少. 未来应进一步拓展研究主题,进行多种视角与跨学科研究,重视实证研究与微观研究.     

Structure and Properties Characterization of Ceramic Coatings Produced on Steel Using a Combined Technique

STEEL is the most widely used material in engineering,but unfortunately,steel exhibits poor wear resistanceand obvious contact corrosion.For decades,researchersprepared coatings on steel to improve its properties;ceramic is one of these coatings.To obtain ceramiccoatings on steel,many researchers use techniques suchas plasma spraying,laser cladding,etc.,but some ofthem are too expensive,some of them have a deep heataffected zone in the substrate,and some of them cannot bond well with the subs…     

改善Fe-B-C合金韧性的研究

为了提高Fe-B-C合金的韧性,应用稀土-钛-氮复合变质剂改善Fe-B-C合金组织和性能。结果发现,Fe-B-C合金复合变质处理后的凝固组织明显细化,且组织分布均匀,并出现钛硼化合物,钛硼化合物不同于普通Fe-B-C合金中的Fe2B呈网状分布,而是呈断网状和块状分布,特别是经高温热处理后,硼化物变成球状和棒状,Fe-B-C合金韧性明显提高,由8～10 J/cm2提高至22～25 J/cm2。经变质处理的Fe-B-C合金可用于制造轧钢机导卫板,其耐磨性比高镍铬合金钢提高1.3倍。     

冲击荷载作用下热处理花岗岩动态力学特性研究

为研究冲击速度和热处理温度对黑云母花岗岩动态力学特性的影响,利用改进的霍普金森压杆系统对25~800 ℃共9个温度等级的热处理试样分别进行3种弹速下的冲击压缩试验。试验结果表明：随着冲击速度的增加,25~700 ℃热处理试样的应力—应变曲线由“Ⅱ型”转变为“Ⅰ型”,而800 ℃热处理试样均表现出“Ⅰ型”应力—应变曲线特征。同一温度热处理下试块的峰值应力、应变和平均应变均随动荷载的升高而增大。相同的冲击速度下,300 ℃热处理试样的动力学性能有所改善,500 ℃后试样的动力学性能开始逐渐劣化。同一温度热处理试样的破碎程度随冲击速度的增加而增加;相同冲击速度下,热处理试样的破碎程度随温度的升高先减弱后增强。     

淬火温度对铸造Fe—B—Ti合金组织和性能的影响

通过不同的热处理淬火温度改变铸造Fe—B—Ti合金的组织，探讨了铸造Fe—B—Ti合金不同组织与性能的关系。试验结果表明：淬火温度较低时，硼化物变化较小，网状分布趋势明显；淬火温度较高时，硼化物断网和团聚化趋势明显加快。淬火温度1050℃时，硼化物网状特征消失，基本上都变成了团块状、颗粒状和杆棒状分布。随着淬火温度升高，硬度和韧性增加，超过1000℃，硬度和韧性变化不明显。淬火温度1050℃时，综合性能良好。     

16MnR 容器板性能不合格的原因

运用扫描电镜、金相检验和力学检验对不合格的16MnR容器板进行了检验分析。结果表明，材料中的条状MnS夹杂物和少量的马氏体、贝氏体组织是导致钢板延伸、冲击性能不合格的主要原因。