压电智能骨料动态拉应力标定试验研究∗

为了监测混凝土内部受拉开裂损伤,提出了混凝土内部拉应力监测压电智能骨料,并对其进行了动态拉应力标定试验研究。首先,制备4个压电智能骨料受拉试件,建立拉应力监测系统;其次,对压电智能骨料施加往复拉应力,标定得到其灵敏度系数;然后,对压电智能骨料试件施加单调荷载直至其受拉破坏,得到其抗拉强度及输出的电压信号,对比了破坏过程的实际与监测荷载。结果表明,往复荷载作用下,SA输出与输入荷载呈良好的线性关系,SA的灵敏度系数一致性较好;单调荷载作用下,各SA抗拉强度均高于混凝土抗拉强度。综上,压电智能骨料有潜力应用于混凝土内部的拉应力监测。     

The Comparative Accuracy of Two Hydrologic Models in Simulating Warm‐Season Runoff for Two Small,Hillslope Catchments

This article assesses the performance of two hydrologic models in simulating warm‐season runoff for two upland, low‐yield micro‐catchments near Coshocton, Ohio. The two models, namely the Storm Water Management Model (SWMM) and the Gridded Surface‐Subsurface Hydrologic Analysis (GSSHA), were implemented with contrasting levels of complexity, with the former representing the catchments as lumped spatial units and computing evaporation only from standing water, and the latter incorporating fine‐scale variation in topography and soil properties and computing evapotranspiration from soil based on weather data. Our investigation began with uncalibrated model runs for 1990‐2003 except for 1994 using a priori parameter values. Then a set of calibration experiments were performed wherein the sensitivity of model performance to the length of calibration records was examined. Our results pointed to large errors associated with simulations from both models: even the calibrated models were unable to reproduce the seasonal and between‐catchment contrasts in runoff response. Using a priori parameter values, SWMM attained better results than GSSHA. However, with simple calibration, GSSHA outperformed SWMM in several respects. It was also found that extending the record of calibration rendered relatively minor changes to model performance. The practical and scientific implications of the findings are discussed.     

矿井瓦斯防爆监测氧含量线性标定

矿井火灾是采矿业面临的安全生产问题之一。该文研究的目的是评估新的矿井瓦斯防爆监测中最重要的成分氧气的检测策略,在矿井火灾中做出预见与预报。对于密封区域,发生瓦斯爆炸危险安全区时氧气浓度小于8%,按照国家标准,本矿要求氧气检测精度达到1%。氧含量监测系统受到气体气路、传感器运行、信号调理与处理情况和终端处理系统等四个方面的影响。该文通过运用计算机控制技术分别对氧含量监测系统进行硬件线性开环标定与软件线性闭环标定,并采用著名的OriginPRO数据分析软件对系统采样数据进行了分析与解读,以达到对软件线性闭环标定进行程控规划和信息实时纠正,使系统氧气含量监测灵敏限小于0.36%。     

灾后复杂地形区域的测量测绘模型设计

灾后地形变化复杂,基于单一线性模型的测量测绘方法,测量灾区坡度陡、高差大等复杂地形时,无法有效拟合复杂地形趋势、获取高程点精度差,导致测量精确度较低。设计一种用于灾后复杂地形区域的测量测绘模型,在外部DEM辅助下精化灾区地形DEM,对灾区遥感InSAR影像进行干涉定标,实现干涉影像与外部DEM的精准对应;将多模型的线性回归策略与灾后复杂地形趋势相拟合,对解缠干涉影像图中全部影像快,通过多模型的线性回归,逐个像素精确的去除相位解缠中多余相位,过滤无价值高程点,得到有效灾区地形高程图,从中采集精确地灾后复杂地形区域高程点。实验结果表明,该模型可提高灾后复杂地形区域绘图精确度,对总体灾区地形InSAR影像测量效率高,测量的平均高程误差为±6.2cm,比单一线性模型低±3.77cm。     

WorldSID假人颈部标定试验方法研究

WorldSID假人是当前侧撞假人的升级,国内只有几个,对其了解较少。为了提高对WorldSID假人的拟人程度,对WorldSID假人颈部标定试验方法及影响因素进行了研究,指出影响颈部标定结果的两个主要因素是吸能蜂窝铝的硬度和颈部本体的强度,该影响因素可通过调整吸能蜂窝铝、颈部缓冲块进行解决。     

Large‐Scale Fine‐Resolution Hydrological Modeling Using Parameter Regionalization in the Missouri River Basin

This study simulated crop and water yields in the Missouri River Basin (MRB; 1,371,000 km²), one of the largest river basins in the United States, using the Soil and Water Assessment Tool (SWAT) at a fine resolution of 12‐digit Hydrological Unit Codes (HUCs) using the regionalization calibration approach. Very few studies have simulated the entire MRB, and those that have developed were at a coarser resolution of 8‐digit HUCs and were minimally calibrated. The MRB was first divided into three subbasins and was further divided into eleven regions. A “head watershed” was selected in each region and was calibrated for crop and water yields. The parameters from the calibrated head watershed were extrapolated to other subwatersheds in the region to complete comprehensive spatial calibration. The simulated crop yields at the head watersheds were in close agreement with observed crop yields. Spatial validation of the aggregated crop yields resulted in reasonable predictions for all crops except dryland corn in a few regions. Simulated and observed water yields in head watersheds and also in the validation locations were in close agreement in naturalized streams and poor agreement in streams with high groundwater‐surface water interactions and/or reservoirs found upstream of the gauges. Overall, the SWAT model was able to reasonably capture the hydrological and crop growth dynamics occurring in the basin despite some limitations.     

水污染分析校准用汞溶液的研制

研制了水污染分析校准用汞溶液。采用原子荧光光谱法对样品进行了均匀性和稳定性检验,对样品的量值进行了验证并进行了不确定度评定。检验结果表明:汞溶液均匀性良好,室温条件下可稳定36个月以上;样品的标准值为100 mg/L,扩展不确定度为2 mg/L。样品量值与美国AccuStandard公司同种标准物质具有一致性。可用于水中汞检测的测定标准、质量控制、分析方法研究以及实验室能力验证等方面。     

PRISM vs. CFSR Precipitation Data Effects on Calibration and Validation of SWAT Models

Precipitation is one of the most important drivers in watershed models. Our objective was to compare two sources of interpolated precipitation data in terms of their effect on calibration and validation of two Soil and Water Assessment Tool (SWAT) models. One model was a suburban watershed in metropolitan Atlanta, Georgia. The precipitation sources were Parameter‐elevation Relationships on Independent Slopes Model (PRISM) data on a 4‐km grid and climate forecast system reanalysis (CFSR) data on a 38‐km grid. The PRISM data resulted in a better fit to the calibration data (Nash Sutcliffe efficiency [NSE] = 0.64, Kling‐Gupta efficiency [KGE] = 0.74, p‐factor = 0.84, and r‐factor = 0.43) than the CFSR data (NSE = 0.47, KGE = 0.53, p‐factor = 0.67, and r‐factor = 0.39). Validation results were similar. Sensitive parameters were similar in both the PRISM and CFSR models, but fitted values indicated more rapid groundwater flow to the streams with the PRISM data. The same comparison was made in the Big Creek watershed located approximately 1,000 km away, in central Louisiana. Results were similar with a more responsive groundwater system indicating PRISM data may produce better predictions of streamflow because of a more accurate estimate of rainfall within a watershed or because of a denser grid. Our study implies PRISM is providing a better estimate than CFSR of precipitation within a watershed when rain gauge data are not available, resulting in more accurate simulations of streamflows at the watershed outlet. Editor's note: This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.     

参数空间分布对非点源污染模拟的影响

以大宁河流域为研究区域,应用非点源模型SWAT（soil and water assessment tool）,模拟了参数空间分布对流域径流和营养物质流失的影响.利用大宁河流域巫溪水文站2000～2004年的实测数据对模型进行了率定和验证,将流域划分为6种数量不等的子流域,利用相同的模型参数输入,模拟了不同的流域划分方案对径流和营养物质流失的影响.结果表明,不同的流域划分方案,年平均流量的最大相对误差为19.6%,6种方案年平均流量的效率系数为0.52～0.82,月平均流量的效率系数为0.80～0.83,随着子流域数量的增加,径流量出现了先下降、后上升的趋势;有机氮和有机磷的最大相对误差分别为16.2%和7.7%,不同的流域划分方案对营养物质的流失产生了轻微的影响,但没有明显的变化趋势和规律.     

荧光法生物气溶胶监测仪标准物质研制及校准方法研究

生物气溶胶监测仪是利用激光或紫外光诱导生物粒子发射荧光,从而实现对空气中的生物气溶胶进行监测的仪器.目前,国内尚无生物气溶胶监测仪校准用标准物质和评价方法.以聚苯乙烯微球为核,通过Friedel-Crafts酰基化反应,研制出能够自身受激发产生荧光的聚苯乙烯(PS-PB)微球.PS-PB微球粒径分布的相对标准偏差为1....