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Application of subsurface wastewater infiltration system to on-site treatment of domestic sewage under high hydraulic loading rate 被引量:7
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作者 Ying-hua Li Hai-bo Li +2 位作者 Xin-yang Xu Xuan Gong Yong-chun Zhou 《Water Science and Engineering》 EI CAS CSCD 2015年第1期49-54,共6页
In order to enhance the hydraulic loading rate (HLR) of a subsurface wastewater infiltration system (SWIS) used in treating domestic sewage, the intermittent operation mode was employed in the SWIS. The results sh... In order to enhance the hydraulic loading rate (HLR) of a subsurface wastewater infiltration system (SWIS) used in treating domestic sewage, the intermittent operation mode was employed in the SWIS. The results show that the intermittent operation mode contributes to the improvement of the HLR and the pollutant removal rate. When the wetting-drying ratio (RwD) was 1.0, the pollutant removal rate increased by (13.6 ± 0.3)% for NH3-N, (20.7 ± 1.1)% for TN, (18.6± 0.4)% for TP, (12.2 ± 0.5)% for BOD, (10.1 ± 0.3)% for COD, and (36.2 ± 1.2)% for SS, compared with pollutant removal rates under the continuous operation mode. The pollutant removal rate declined with the increase of the HLR. The effluent quality met The Reuse of Urban Recycling Water - Water Quality Standard for Scenic Environment Use (GB/T 18921-2002) even when the HLR was as high as 10 cm/d. Hydraulic conductivity, oxidation reduction potential (ORP), the quantity of nitrifying bacteria, and the pollutant removal rate of NH3-N increased with the decrease of the RWD. For the pollutant removal rates of TP, BOD, and COD, there were no significant difference (p 〈 0.05) under different RwDS. The suggested RWD was 1.0. Relative contribution of the pretreatment and SWlS to the pollutant removal was examined, and more than 80% removal of NH3-N, TN, TP, COD, and BOD occurred in the SWIS. 展开更多
关键词 Domestic sewage Subsurface wastewater infiltration system Intermittent operation mode Hydraulic loading rate Pollutant removal rate
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Dynamic monitoring of soil bulk density and infiltration rate during coal mining in sandy land with different vegetation 被引量:9
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作者 Yinli Bi Hui Zou Chenwei Zhu 《International Journal of Coal Science & Technology》 EI CAS 2014年第2期198-206,共9页
To investigate the effects of coal mining on soil physical properties,sandy lands with three major vegetation types(Salix psammophila,Populus simonii,and Artemisia ordosica)were investigated by the ring knife method a... To investigate the effects of coal mining on soil physical properties,sandy lands with three major vegetation types(Salix psammophila,Populus simonii,and Artemisia ordosica)were investigated by the ring knife method and double-ring infiltrometer.Specifically,variations in soil bulk density and water infiltration rate and the influences of coal mining and vegetation type on the properties during different subsidence stages were studied at the Shendong Bulianta mine.The results showed that,in the period before mining,soil bulk density occurred in the order A.ordosica>P.simonii>S.psammophila,with a negative correlation between the initial infiltration rate and steady infiltration rate being observed.In the period during mining and 3 months after mining,there were no significant differences in soil bulk density and water infiltration rate among vegetation types.At 1 year after mining,the soil bulk density occurred in the order A.ordosica>S.psammophila>P.simonii,having a negative correlation with the steady infiltration rate.The water infiltration depths of the S.psammophila,P.simonii and A.ordosica were 50,60,and 30 cm,respectively.The infiltration characters were simulated by the Kostiakov equations,and the simulated and experimental results were consistent.Linear regression revealed that vegetation types and soil bulk density had significant effects on soil initial infiltration rate during the four study periods,and the infiltration rate of the period 1 year after mining was mainly influenced by the soil bulk density of the period before mining.The results indicated that vegetation types had significant effects on soil bulk density,and that the tree-shrub-grass mode was better than one single plantation for water conversation and vegetation recovery in sandy land subjected to mining. 展开更多
关键词 Soil bulk density Soil infiltration rate Sandy land Vegetation type
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Threshold pressure and infiltration behavior of liquid metal into fibrous preform 被引量:2
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作者 关俊涛 齐乐华 +2 位作者 刘健 周计明 卫新亮 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第11期3173-3179,共7页
A dynamic measuring apparatus was developed to investigate the infiltration process of liquid metal into the fibrous preform. 10% (volume fraction) chopped carbon fiber preforms were infiltrated with magnesium alloy... A dynamic measuring apparatus was developed to investigate the infiltration process of liquid metal into the fibrous preform. 10% (volume fraction) chopped carbon fiber preforms were infiltrated with magnesium alloy under different infiltration pressures. The threshold pressure and flow behavior of liquid metal infiltrating into the preforms were calculated and measured. The microstructure of obtained Ct4Mg composites was observed. The results indicate that the measured threshold pressure for infiltration was 0.048 MPa, which was larger than the calculated value. The infiltration rate increased with the increase of infiltration pressure, but the increase amplitude decreased gradually. The tiny pores in the composites could be eliminated by increasing the infiltration pressure. When the infiltration pressure rose to 0.6 MPa, high quality C1/Mg composite was obtained. 展开更多
关键词 metal matrix composites carbon fiber Mg PERFORM infiltration threshold pressure infiltration rate
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Fuzzy Analytical Solution to Vertical Infiltration 被引量:2
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作者 Christos Tzimopoulos George Papaevangelou +2 位作者 Kyriakos Papadopoulos Christos Evangelides George Arampatzis 《Journal of Software Engineering and Applications》 2020年第4期41-66,共26页
In this article, we examine the solution of the fuzzy linear vertical infiltration equation, which represents the water movement in porous media in that part which is called the vadose zone. This zone is very importan... In this article, we examine the solution of the fuzzy linear vertical infiltration equation, which represents the water movement in porous media in that part which is called the vadose zone. This zone is very important for semi-arid areas, due to complex phenomena related to the moisture content in it. These phenomena concern the interchange of moisture content between the vadose zone and the atmosphere, groundwater and vegetation, transfer of moisture and vapor and retention of moisture. The equation describing the problem is a partial differential parabolic equation of second order. The calculation of water flow in the unsaturated zone requires the knowledge of the initial and boundary conditions as well as the various soil parameters. But these parameters are subject to different kinds of uncertainty due to human and machine imprecision. For that reason, fuzzy set theory was used here for facing imprecision or vagueness. As the problem concerns fuzzy differential equations, the generalized Hukuhara (gH) derivative was used for total derivatives, as well as the extension of this theory for partial derivatives. The results are the fuzzy moisture content, the fuzzy cumulative infiltration and the fuzzy infiltration rate versus time. These results allow researchers and engineers involved in Irrigation and Drainage Engineering to take into account the uncertainties involved in infiltration. 展开更多
关键词 FUZZY PARTIAL Differential gH-Derivative CUMULATIVE infiltration infiltration rate
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Clogging Process Caused by Organic Particle Accumulation and Biofilm Growth in Subsurface Wastewater Infiltration System
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作者 潘晶 于龙 王艳 《Journal of Donghua University(English Edition)》 EI CAS 2012年第2期187-192,共6页
Substrate clogging is the worst operational problem for subsurface wastewater infiltration system ( SWIS ), nevertheless quantitative understanding of the clogging process is currently very limited. In this study, t... Substrate clogging is the worst operational problem for subsurface wastewater infiltration system ( SWIS ), nevertheless quantitative understanding of the clogging process is currently very limited. In this study, the developing process of clogging caused by organic particle accumulation and biofilm growth was investigated in two groups of lab-scale SWIS, which were fed with glucose (dissolved organic matter) and starch (particulate organic matter) influent and filled with the same substrate made of 50% brown soil and cinder at a weight of 50%. Results showed that in glucose-fed systems the growth of biofilm in the substrate pores certainly caused remarkable reduction of effective porosity, especially for the high concentration organic wastewater, whereas its influence on infiltration rate was negligible. In comparison with biofllm growth, organic particles accumulation could rapidly reduce infiltration rate and the clogging occurred in the upper layer in starch-fed systems and the most important contribution of biofilm growth to clogging was accelerating the occurrence of clogging. 展开更多
关键词 subsutface wastewater infiltration system (SWIS) organic particle accumulation infiltration rate effective porosity
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Estimation and inter-comparison of infiltration models in the agricultural area of the Mitidja Plain, Algeria
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作者 Amina MAZIGHI Hind MEDDI +3 位作者 Mohamed MEDDI Ishak ABDI Giovanni RAVAZZANI Mouna FEKI 《Journal of Arid Land》 SCIE CSCD 2023年第12期1474-1489,共16页
Infiltration is an important part of the hydrological cycle, and it is one of the main abstractions accounted for in the rainfall-runoff modeling. The main purpose of this study is to compare the infiltration models t... Infiltration is an important part of the hydrological cycle, and it is one of the main abstractions accounted for in the rainfall-runoff modeling. The main purpose of this study is to compare the infiltration models that were used to assess the infiltration rate of the Mitidja Plain in Algeria. Field infiltration tests were conducted at 40 different sites using a double ring infiltrometer. Five statistical comparison criteria including root mean squared error(RMSE), normalized root mean squared error(NRMSE), coefficient of correlation(CC), Nash-Sutcliffe efficiency(NSE), and Kling-Gupta efficiency(KGE) were used to determine the best performing infiltration model and to confirm anomalies between predicted and observed values. Then we evaluated performance of five models(i.e., the Philip model, Kostiakov model, Modified Kostiakov model, Novel model, and Horton model) in simulating the infiltration process based on the adjusted performance parameters cited above. Results indicated that the Novel model had the best simulated water infiltration process in the Mitidja Plain in Algeria. However, the Philip model was the weakest to simulate the infiltration process. The conclusion of this study can be useful for estimating infiltration rate at various sites using a Novel model when measured infiltration data are not available and are useful for planning and managing water resources in the study area. 展开更多
关键词 infiltration rate infiltration model double ring infiltrometer Mitidja Plain Novel model
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Effects of Organic Compound Fertilizers on Soil Water Infiltration Characteristics
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作者 Jianqi LAN Shiyou XIE 《Agricultural Biotechnology》 CAS 2020年第4期104-110,167,共8页
In order to study the effects of organic compound fertilizers on soil water infiltration characteristics,an indoor one-dimensional soil column water infiltration test was carried out.Six soil sample treatment groups w... In order to study the effects of organic compound fertilizers on soil water infiltration characteristics,an indoor one-dimensional soil column water infiltration test was carried out.Six soil sample treatment groups were set,namely marshy solonchak(control check,CK for short),bamboo charcoal-mixed marshy solonchak,Difuyuan-mixed marshy solonchak,salined flavo-aquic soil(CK),bamboo charcoal-mixed salined flavo-aquic soil and Difuyuan-mixed salined flavo-aquic soil.After 120 min of infiltration,compared with the CK groups of marshy solonchak and salined flavo-aquic soil,the cumulative infiltration volumes of the bamboo charcoal and difuyuan treatment groups increased by -18.78%,-3.93% and 25.77%,6.53%,respectively;and the displacement increased by -18.93%,1.64% and 22.6%,12.5%,respectively.The relationship between the wetting front displacement and time conformed to a linear function.The effects of organic compound fertilizers on the initial infiltration rates of marshy solonchak and salined flavo-aquic soil were significant,and the relationship between infiltration rate and time conformed to a power function.The vertical distribution of soil moisture under the application of organic compound fertilizers showed that the moisture content changed relatively small within 5 cm of the surface soil layer,then decreased slowly within 5-10 cm of the soil layer,and decreased drastically below 10 cm of soil layer;and relative to the CK group,the application of organic compound fertilizers was beneficial to increase the moisture content of salined flavo-aquic soil.The organic compound fertilizers reduced the water infiltration capacity of marshy solonchak and improved the water infiltration capacity of salined flavo-aquic soil.Compared with Difuyuan,bamboo charcoal reduced the water infiltration capacity of marshy solonchak better and improved the water permeability of salined flavo-aquic soil more significantly. 展开更多
关键词 Organic compound fertilizer Wetting front Cumulative infiltration volume infiltration rate Soil moisture
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Comparison of models to predict air infiltration rate of buildings with different surrounding environments
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作者 Shu Zheng Xiujiao Song +2 位作者 Lin Duanmu Yu Xue Xudong Yang 《Building Simulation》 SCIE EI CSCD 2024年第6期1007-1021,共15页
The air infiltration rate of buildings strongly influences indoor environment and energy consumption.In this study,several traditional methods for determining the air infiltration rate were compared,and their accuracy... The air infiltration rate of buildings strongly influences indoor environment and energy consumption.In this study,several traditional methods for determining the air infiltration rate were compared,and their accuracy in different scenarios was examined.Additionally,a method combining computational flow dynamics(CFD)with the Swami and Chandra(S-C)model was developed to predict the influence of the surrounding environment on the air infiltration rate.Two buildings in Dalian,China,were selected:one with a simple surrounding environment and the other with a complex surrounding environment;their air infiltration rates were measured.The test results were used to validate the accuracy of the air infiltration rate solution models in different urban environments.For the building with a simple environment,the difference between the simulation and experimental results was 0.86%–22.52%.For the building with a complex environment,this difference ranged from 17.42%to 159.28%.We found that most traditional models provide accurate results for buildings with simple surrounding and that the simulation results widely vary for buildings with complex surrounding.The results of the method of combining CFD with the S-C model were more accurate,and the relative error between the simulation and test results was 10.61%.The results indicate that the environment around the building should be fully considered when calculating the air infiltration rate.The results of this study can guide the application of methods of determining air infiltration rate. 展开更多
关键词 air infiltration rate models CFD simulation building surrounding air infiltration rate test
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High strain rate superplasticity of SiC whisker reinforced pure aluminum composites 被引量:4
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作者 Xu Xiaojing(许晓静) Zhao Changzheng(赵昌正) +2 位作者 Zhang Di(张 荻) Shi Zhongliang(施忠良) Wu Renjie(吴人洁) 《中国有色金属学会会刊:英文版》 EI CSCD 1999年第3期500-504,共5页
A β SiC whisker reinforced pure aluminum composites expected to exhibit high strain rate superplasticity has been successfully fabricated by a new processing route consisting of pressure infiltration, extrusion with ... A β SiC whisker reinforced pure aluminum composites expected to exhibit high strain rate superplasticity has been successfully fabricated by a new processing route consisting of pressure infiltration, extrusion with a low extrusion ratio and rolling. The composites exhibite a total elongation of 220%~380% in the initial strain rates within 1.0×10 -2 ~1.0×10 -1 s -1 and at 893~903 K. According to differential thermal analysis(DTA) and microstructure observation, it is concluded that an appropriately small amount of liquid phase is necessary to cause a good high strain rate superplasticity in aluminum matrix composites in addition to fine and uniform microstructure. 展开更多
关键词 high STRAIN rate SUPERPLASTICITY ALUMINUM matrix COMPOSITES pressure infiltration
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Indices to monitor biological soil crust growth rate - lab and field experiments 被引量:1
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作者 Avraham Dody Roni Hakmon +1 位作者 Boaz Asaf Eli Zaady 《Natural Science》 2011年第6期478-483,共6页
The aim of this work was to identify test meth-ods for accelerating growth of biological soil crust (BSC). The BSC in the Yamin Plateau in the north-east of the Negev Desert is composed of cyanobacteria such as microc... The aim of this work was to identify test meth-ods for accelerating growth of biological soil crust (BSC). The BSC in the Yamin Plateau in the north-east of the Negev Desert is composed of cyanobacteria such as microcoleus spp. nostoc spp. and others. Cyanobacteria are well adapted to dry environments, owing to their ability to survive desiccation, high temperatures and solar radiation. Since the BSC is a live component in the ecosystem, it can repair itself in the event of failures such as environmental disturbances by living things. In the lab, we used five different treatments and mediums: natural BSC, pure sand as reference, pure sand with spores and propagules, pure sand with whey, and pure sand with spores and propa-gules and whey. The spores were collected from specified collecting areas in the field. Each Petri dish was irrigated daily with 10 mL of double- distilled water. The testing period ran for 4.5 months with 10 samples taken from each treatment at 1.5 month intervals. The analyses criteria were: NDVI for chlorophyll content by remote sensing techniques, polysaccharide content, infiltration rate through the crust, pro-tein and organic content. The results showed that NDVI, polysaccharides and infiltration rates are good indicators for showing growth accel-eration of the crust;while protein and organic content were found to be less indicative. The treatments using whey for preliminary crust failed in the lab since cracks were observed, but succeeded in the field experiments. In the field, we measured only the chlorophyll content with a time interval of 20 months. The methodology of how to accelerate the growth of BSC was found to be effective. 展开更多
关键词 Microcoleus SPP SPORES NDVI infiltration rate POLYSACCHARIDES Content
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Double-Ring Infiltrometer for <i>In-Situ</i>Permeability Determination of Dam Material 被引量:1
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作者 Hans Ronnqvist 《Engineering(科研)》 2018年第6期320-328,共9页
Three types of natural soils are studied in this paper: 1) a postglacial silt, 2) a glacial till, and 3) a postglacial sand. The former two are soils from embankment dam sites in Sweden, and the latter is a soil from ... Three types of natural soils are studied in this paper: 1) a postglacial silt, 2) a glacial till, and 3) a postglacial sand. The former two are soils from embankment dam sites in Sweden, and the latter is a soil from a natural deposit situated in the Swedish east coastal region. In situ Double-ring infiltrometer (DRI) tests are compared with laboratory constant-head permeability determinations. This study shows that the DRI tests conducted on sandy-silty soils are within sufficient range to the laboratory results, to suggest that in situ near-saturated infiltration capacity may be used as a field estimate of hydraulic conductivity (permeability) for this range of soils. In situ infiltrometer testing may be the better alternative when there is difficulty in achieving representative field conditions in a laboratory setting, e.g., for widely graded soils such as glacial tills. 展开更多
关键词 Double-Ring infiltrometer DRI Hydraulic Conductivity PERMEABILITY infiltration rate Postglacial SILT Sand GLACIAL TILL
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W-OH固化剂对高寒矿区煤矸石水分入渗的影响及模型拟合
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作者 杨鹏辉 杨海龙 +2 位作者 杨思远 张巍 张颂扬 《干旱区地理》 CSCD 北大核心 2024年第9期1542-1554,共13页
采用室内积水条件下煤矸石柱水分入渗模拟试验,研究了不同浓度W-OH(0%、1.5%、2.5%和3.5%)喷施处理对高寒矿区煤矸石水分入渗的影响,同时采用Philip、Kostiakov和Horton 3种入渗模型对入渗过程进行拟合,利用一维代数模型预测煤矸石剖面... 采用室内积水条件下煤矸石柱水分入渗模拟试验,研究了不同浓度W-OH(0%、1.5%、2.5%和3.5%)喷施处理对高寒矿区煤矸石水分入渗的影响,同时采用Philip、Kostiakov和Horton 3种入渗模型对入渗过程进行拟合,利用一维代数模型预测煤矸石剖面体积含水率分布特征,并评价模型适用性。结果表明:(1)累计入渗量和湿润锋前进距离随入渗时间的增加而逐渐增加且与WOH浓度存在负相关性。同一入渗时刻,W-OH浓度越大,入渗率和湿润锋前进速率越小,与对照(0%W-OH)相比,3种W-OH浓度(1.5%、2.5%、3.5%)处理的初始入渗率分别降低了1.12%、3.59%和9.64%,稳定入渗率分别降低了16.92%、78.46%和89.23%,平均入渗率分别降低了11.35%、58.26%和71.02%。(2)3种入渗模型都能较好地拟合不同浓度W-OH处理煤矸石水分入渗过程,Philip、Kostiakov和Horton模型的决定系数(R2)均值分别为0.962、0.957和0.967,其中Horton模型的拟合效果较好。(3)积水入渗过程中同一W-OH浓度,埋深越大,水分入渗至各监测点所需的时间越长,同一深度,W-OH浓度越大,水分入渗至各监测点所需的时间也越长。(4)一维代数模型可以较好地模拟入渗结束后煤矸石剖面体积含水率分布特征,模拟值与实测值间的均方根误差(RMSE)和平均绝对误差(MAE)分别在2.574%~3.326%之间和2.308%~2.707%之间,符合度指数(D)均在0.92以上。研究结果可以为W-OH固化剂在高寒矿区煤矸石山冻土剖面重构中的应用提供理论指导。 展开更多
关键词 煤矸石 W-OH 累计入渗量 入渗率 湿润锋 模型拟合
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模拟降雨条件下重构阻水层对坡面风化煤矸石产流产沙的影响
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作者 张颂扬 张巍 +2 位作者 杨鹏辉 杨思远 杨海龙 《水土保持通报》 CSCD 北大核心 2024年第2期101-109,共9页
[目的]为缓解水分因子对高寒矿区扰动土体无法形成冻土带来的不利影响,研究提出扰动土体下方添加高阻水性材料亲水性聚氨酯(W-OH)重构底部阻水层(近似无缝隙的不透水层)的设计方案,分析重构阻水层后高寒矿区风化煤矸石坡面入渗、产流和... [目的]为缓解水分因子对高寒矿区扰动土体无法形成冻土带来的不利影响,研究提出扰动土体下方添加高阻水性材料亲水性聚氨酯(W-OH)重构底部阻水层(近似无缝隙的不透水层)的设计方案,分析重构阻水层后高寒矿区风化煤矸石坡面入渗、产流和产沙的变化特征,为高寒矿区扰动坡面冻土重现以及重构阻水层的坡面水土流失防治提供理论支撑。[方法]通过人工模拟降雨试验,研究在60和90 mm/h降雨雨强条件下,重构阻水层(添加W-OH浓度0%,1.5%,2.5%,3.5%,4.5%)后不同坡度条件的(3种坡度5°,15°,25°)的风化煤矸石坡面入渗特性和水土流失变化规律。[结果]①重构阻水层后的煤矸石坡面稳定入渗率较自然坡面明显降低,且与W-OH添加浓度呈负相关关系;②煤矸石坡面产流率随时间变化呈现先快速上升后逐渐平稳的变化趋势,平均产流率与W-OH添加浓度呈现正相关关系,添加浓度为1.5%,2.5%,3.5%,4.5%W-OH的煤矸石坡面平均产流率较自然状态增加26.75%,38.02%,46.90%,63.23%;③坡面平均流速与降雨雨强、W-OH添加浓度和坡度均呈正相关关系,影响程度表现为:降雨雨强>坡度>W-OH添加浓度。④坡面产沙率随时间变化曲线多为“单峰”曲线,呈现先迅速上升随后缓慢下降最终趋于稳定的变化趋势,添加浓度为1.5%,2.5%,3.5%,4.5%W-OH的煤矸石坡面平均产沙率较自然状态增加26.98%,49.48%,71.64%,94.01%。[结论]重构阻水层对坡面风化煤矸石渗透性能降低明显,能有效帮助高寒矿区扰动坡面的冻土恢复和形成,但入渗率的降低使坡面更容易产生径流,增加了地表的产流产沙,可配置一定的水土保持措施。 展开更多
关键词 入渗率 产流率 产沙率 风化煤矸石
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磁化微咸水对南疆盐渍土壤水分入渗及盐分淋出特征的影响
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作者 彭永倩 王则玉 +4 位作者 朱连勇 朱珠 江龙 孔芊芊 王立成 《节水灌溉》 北大核心 2024年第9期21-29,共9页
为探究磁化微咸水灌溉对南疆盐渍土入渗及盐分离子迁移特征的影响,采用恒定磁场强度400 mT对矿化度分别为0、2、3、5 g/L微咸水进行磁化处理,以未磁化处理为对照,对比分析各处理累积入渗量、湿润锋运移距离和淋洗后不同土壤剖面总盐、... 为探究磁化微咸水灌溉对南疆盐渍土入渗及盐分离子迁移特征的影响,采用恒定磁场强度400 mT对矿化度分别为0、2、3、5 g/L微咸水进行磁化处理,以未磁化处理为对照,对比分析各处理累积入渗量、湿润锋运移距离和淋洗后不同土壤剖面总盐、脱盐率、盐分离子和SAR的影响规律。结果表明:磁化微咸水入渗减小了相同时间内的累积入渗量和湿润锋深度,降低了Philip入渗模型吸渗率,土壤含水率比未磁化微咸水提高5.00%~6.29%;磁化处理显著降低了土壤含盐量,对0~50 cm土壤内总盐含量磁化处理较未磁化降低11.79%~41.64%,在同一磁化强度下,土壤含盐量随矿化度的增加而增加,脱盐率随矿化度的增加而降低。在同一矿化度下,磁化处理含盐量低于未磁化处理,脱盐率高于未磁化处理。磁化微咸水灌溉有利于降低土壤中盐分离子含量,0~50 cm土层K^(+)、Na^(+)、Ca^(2+)、Mg^(2+)、HCO_(3)^(-)、Cl^(-)、SO_(4)^(2-)含量磁化较未磁化处理降低16.90%~25.97%、43.62%~64.68%、11.15%~31.44%、-8.12%~49.07%、-74.14%~13.43%、21.46%~52.81%、6.66%~13.10%。磁化微咸水灌溉处理显著降低0~50 cm土层深度处土壤SAR。 展开更多
关键词 磁化微咸水 盐渍土 入渗特征 盐分淋洗 土壤脱盐率
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横坡垄作措施下层状棕壤的积水入渗特征及其模拟
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作者 亓益品 窦永辉 +2 位作者 王亚楠 肖培青 安娟 《中国水土保持科学》 CSCD 北大核心 2024年第4期59-67,共9页
横坡垄作系统中雨水/灌溉水易在垄沟低洼处积聚,诱发积水入渗,使入渗特性有别于传统耕作系统。基于横坡垄作垄沟内积水特征,采用室内土柱供水实验,以层状棕壤为研究对象,分析5个积水深度(2、4、6、8和12 cm)下入渗率、湿润锋运移动态变... 横坡垄作系统中雨水/灌溉水易在垄沟低洼处积聚,诱发积水入渗,使入渗特性有别于传统耕作系统。基于横坡垄作垄沟内积水特征,采用室内土柱供水实验,以层状棕壤为研究对象,分析5个积水深度(2、4、6、8和12 cm)下入渗率、湿润锋运移动态变化,并利用修正的Gree n-Ampt模型对积水入渗过程进行模拟。结果表明:1)耕层阶段,入渗率呈急剧下降后趋于稳定趋势;过渡阶段,入渗率稳定一定时段后逐渐降低;犁底层阶段,入渗率趋于稳定;2)积水深度的增加均促进湿润锋的运移,但未改变湿润锋运移过程;3)初始入渗率、稳定入渗率、平均入渗率、累积入渗量等入渗参数均随积水深度增加呈幂函数增大,其中积水深度12、8、6和4 cm下的平均入渗率较积水深度2 cm分别增加120.5%、65.4%、39.4%和29.9%;4)在解析积水深度(h)与饱和导水率(K_(s)(h))间呈线性正相关关系基础上(K_(s)(h)=0.092h+0.76),结合湿润锋处土壤吸力(25.61 cm),构建模拟积水入渗过程的修正Green-Ampt模型。积水深度的增加加快土壤水分入渗,可利用修正Green-Ampt模型对积水入渗过程进行模拟。研究结果可为横坡垄作措施下水分高效利用、水资源调控提供科学依据。 展开更多
关键词 积水深度 入渗率 湿润锋运移 修正Gree n-Ampt模型 横坡垄作
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北方土石山区坡面水土流失特征研究 被引量:3
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作者 李子君 刘家圆 王海军 《水土保持研究》 CSCD 北大核心 2024年第1期1-9,共9页
[目的]揭示北方土石山区坡面水土流失规律,为山区土壤侵蚀防治和生态建设提供科学依据。[方法]利用1988—1991年坡面径流小区观测数据,运用统计和相关分析等方法,对不同下垫面条件下坡面水土流失特征进行了分析,并探讨了坡面径流深度、... [目的]揭示北方土石山区坡面水土流失规律,为山区土壤侵蚀防治和生态建设提供科学依据。[方法]利用1988—1991年坡面径流小区观测数据,运用统计和相关分析等方法,对不同下垫面条件下坡面水土流失特征进行了分析,并探讨了坡面径流深度、土壤侵蚀模数、土壤入渗率与有效降雨量、平均降雨强度、降雨历时、降雨等级的关系。[结果](1)在5°08′~24°08′坡度范围内,坡面径流深度随坡度增加逐渐减小,土壤侵蚀模数和土壤入渗率随坡度增加逐渐增大;(2)在2.18~33.19 m坡长范围内,坡面径流深度随坡长增加逐渐减小,土壤侵蚀模数和土壤入渗率随坡长增加呈现先增后减的变化趋势,存在临界坡长;(3)随着植被覆盖度增加,坡面径流深度、土壤侵蚀模数迅速减小,土壤入渗率逐渐增加;裸地的坡面径流深度和土壤侵蚀模数显著高于30%植被覆盖度坡面,但植被覆盖度由30%增加到60%,90%时,坡面水土流失过程的影响差异并不明显,说明在水土流失治理中存在临界植被覆盖度;(4)坡面径流深度、土壤侵蚀模数主要受到有效降雨量和平均降雨强度影响,且均呈显著正相关;而土壤入渗率主要受到平均降雨强度和降雨历时影响,与平均降雨强度呈显著正相关,与降雨历时呈显著负相关;随降雨等级的增加,坡面径流深度和土壤侵蚀模数呈增加趋势而土壤入渗率呈先增加后减少的趋势。[结论]下垫面条件和降雨因素对北方土石山区坡面水土流失过程产生了重要影响。未来应结合室内试验和模型模拟,进一步加强该区域不同自然因素和人类活动对坡面水土流失过程和影响机制的研究。 展开更多
关键词 下垫面条件 降雨 径流深度 土壤侵蚀模数 土壤入渗率 北方土石山区
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多裂肌脂肪浸润的Goutallier分级与腰椎融合术后相邻节段退变的相关性分析
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作者 尚琦松 向伟 +5 位作者 陆云 李哲 郑俊儒 王兴 王晓楠 宋兴华 《颈腰痛杂志》 2024年第5期820-824,共5页
目的探讨多裂肌脂肪浸润Goutallier分级与腰椎融合术后邻近节段退变(ASD)的相关性。方法选择2017年1月至2020年6月在该院接受经椎间孔腰椎椎间融合术(TLIF)治疗的168例L 4腰椎滑脱患者资料进行回顾性分析,根据轴向T1加权MRI图像,采用Gou... 目的探讨多裂肌脂肪浸润Goutallier分级与腰椎融合术后邻近节段退变(ASD)的相关性。方法选择2017年1月至2020年6月在该院接受经椎间孔腰椎椎间融合术(TLIF)治疗的168例L 4腰椎滑脱患者资料进行回顾性分析,根据轴向T1加权MRI图像,采用Goutallier分级对L 3、L 4、L 5节段的多裂肌脂肪浸润情况进行评估。观察术后ASD发生率,观察是否ASD患者术前多裂肌的Goutallier分级,以及患者术前多裂肌的Goutallier分级与术后发生ASD的关系。结果随访期间共有41例出现ASD,发生率24.40%。ASD组L 3、L 4、L 5节段的多裂肌脂肪浸润程度均显著高于非ASD患者,差异均有统计学意义(P<0.05)。ASD组患者年龄、骨盆倾斜角(PT)、腰椎前凸角(LL)、术前邻近节段退变的占比高于非ASD组,骶骨倾斜角(SS)低于非ASD组,差异均有统计学意义(P<0.05);ASD和非ASD患者的性别和体质量指数差异无统计学意义(P>0.05)。多因素Logistic回归分析显示,控制混杂因素后,术前多裂肌的Goutallier分级是ASD的风险因素,L 3节段多裂肌的Goutallier分级与ASD的OR值最高。结论术前多裂肌Goutallier分级是退行性腰椎滑脱患者行TLIF术后发生ASD的风险因素。 展开更多
关键词 腰椎滑脱 经椎间孔腰椎椎体间融合术 邻近节段退变 多裂肌 脂肪浸润 Goutallie
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层状地质条件下注浆模型渗流场解析解
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作者 魏福成 汪镇 周凤玺 《科学技术与工程》 北大核心 2024年第29期12723-12733,共11页
基于地下水动力学,将隧道注浆过程与地下水向完整井运动类比,并建立层状地质条件下渗流模型;通过保角变换法,将求解问题由平面径向流转换为平面均匀流,求解了层状地质条件渗流场解析解。在此基础上,将隧道注浆模型简化为三层地层,求解... 基于地下水动力学,将隧道注浆过程与地下水向完整井运动类比,并建立层状地质条件下渗流模型;通过保角变换法,将求解问题由平面径向流转换为平面均匀流,求解了层状地质条件渗流场解析解。在此基础上,将隧道注浆模型简化为三层地层,求解了隧道渗流量、注浆圈外水压力、衬砌外水压力解析解。为验证解的有效性,以团结隧道为背景,采用等效面积法进行数值模拟。结果显示:在注浆圈厚度增加、注浆圈渗透系数与衬砌渗透系数减小的情况下,隧道的涌水量及衬砌外水压力会减小,堵水率和注浆圈外水压力将增加。通过误差分析发现,与解析解相比较,同心圆断面误差随着注浆圈厚度误差增加,六心圆断面误差减小,模拟解两断面涌水量结果接近59%;随着注浆圈渗透系数的减小,模拟解与解析解涌水量相对误差均较大;随着衬砌渗透系数的减小,涌水量与衬砌外水压力的模拟解均大于解析解。 展开更多
关键词 隧道工程 层状地质 注浆模型 渗流量 衬砌外水压力
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Creep property research of new martensite heat-resistant steel G115
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作者 ZHAI Guoli 《Baosteel Technical Research》 CAS 2024年第3期23-28,共6页
G115 steel was jointly developed by China Iron & Steel Research Institute Group Co.,Ltd.and Baosteel for usage in 600-650 ℃ ultrasupercritical boiler tubes.Using a hot extruded G115 tube,creep tests were conducte... G115 steel was jointly developed by China Iron & Steel Research Institute Group Co.,Ltd.and Baosteel for usage in 600-650 ℃ ultrasupercritical boiler tubes.Using a hot extruded G115 tube,creep tests were conducted under a constant stress of 130 MPa and temperatures of 625,650 and 675 ℃.Comparing creep curves under different temperatures,it is observed that the creep performance of a G115 tube is more sensitive to temperature than stress.Steady-state creep rates of creep specimens are significantly increased by enhancing the temperature.A micro-structural analysis of ruptured creep specimens under a stress of 130 MPa and temperatures of 650 ℃ and 675 ℃ was performed;the fracture mechanism of creep specimens under these two temperatures mainly included the appearance of creep holes on the grain boundary and a decrease in the martensite lath density. 展开更多
关键词 G115 steel creep property steady-state creep rate
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石灰与水泥改良粉质黏土的水稳定性试验研究
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作者 胡月峰 刘泽 +2 位作者 李洪 陈天龙 吴疆 《市政技术》 2024年第10期78-84,共7页
为探究粉质黏土采用石灰和水泥改良后的水稳定性,设计并制作了不同石灰和水泥掺量的改良粉质黏土试样,并通过自制的崩解仪开展了崩解试验。试验结果表明,未掺加改良剂的素粉质黏土试样浸水后会迅速崩解,且崩解过程具有明显的阶段性。当... 为探究粉质黏土采用石灰和水泥改良后的水稳定性,设计并制作了不同石灰和水泥掺量的改良粉质黏土试样,并通过自制的崩解仪开展了崩解试验。试验结果表明,未掺加改良剂的素粉质黏土试样浸水后会迅速崩解,且崩解过程具有明显的阶段性。当石灰掺量小于6%时,改良粉质黏土试样在水中发生崩解,但其耐崩性会随石灰掺量和压实度的增加而提升。当石灰掺量达到6%、水泥掺量达到2%时,改良粉质黏土试样在水中未发生崩解,但水仍会渗入试样内部,此时可采用入渗率描述试样的水稳定性。改良粉质黏土试样的入渗率会随压实度的增加而降低;相同压实度下改良粉质黏土试样的入渗率随改良剂掺量的增加而降低。相同掺量下水泥改良粉质黏土的水稳定性提升效果优于石灰改良粉质黏土,且水泥的改良效果相当于多掺2%的石灰,但水泥掺量不宜低于2%。 展开更多
关键词 粉质黏土 改良 崩解率 崩解速率 入渗率
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