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Precipitation Forecast Test Based on MODE
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作者 Wang Xuelian Xie Yiyang +2 位作者 Li Yinghua Chen Min Zhong Jiqin 《Meteorological and Environmental Research》 CAS 2014年第2期5-8,共4页
Abstract By testing and analyzing BJ-RUC forecast of one precipitation process, MODE was introduced. MODE could give objective comparison from position of precipitation falling zone, shape and direction, and reflect i... Abstract By testing and analyzing BJ-RUC forecast of one precipitation process, MODE was introduced. MODE could give objective comparison from position of precipitation falling zone, shape and direction, and reflect intensity difference between forecast and actual situation, which comprehensively reflected precipitation forecast performance of the model, and was close to subjective judgment thinking of forecaster. 展开更多
关键词 MODE Precipitation forecast testing and analysis China
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The Mid-Term Model Forecast Test of North China Rainstorm from July 19th to 20th, 2016
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作者 Xiakun Zhang Qiqi Liu Manyu Zhang 《Journal of Geoscience and Environment Protection》 2017年第8期166-180,共15页
Heavy rain is a kind of severe weather, often causing floods and serious soil erosion, leading to engineering losses, embankment rupture and crop flooding and other significant economic losses. Especially for some low... Heavy rain is a kind of severe weather, often causing floods and serious soil erosion, leading to engineering losses, embankment rupture and crop flooding and other significant economic losses. Especially for some low-lying terrain areas, rainwater cannot quickly vent caused by farm water and soil moisture being too saturated, so it will cause more geological disasters. This article combines live and forecast data, aiming at the results of the mid-rainstorm forecast in North China during the period of 7.19-2016, and compares with the actual situation of rainstorm. We carry out the mid-term forecast of the rainstorm. The atmosphere is a kind of medium with various fluctuation phenomena, and its physical properties and changes are studied by the analysis of volatility which is an important research method. It is important to improve the accuracy of such severe weather forecasting rainstorms and to take precautionary measures in a timely manner to minimize the losses caused by rainstorms. 展开更多
关键词 Heavy Rain North China Medium-Term Model forecast test
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Forecasting and Evaluating the Efficiency of Test Generation Algorithms by Genetic Algorithm 被引量:1
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作者 Shiyi Xu and Wei Cen School of Computers Shanghai University, Shanghai, China 200072 《湖南大学学报(自然科学版)》 EI CAS CSCD 2000年第S2期86-94,共9页
To generate a test set for a given circuit (including both combinational and sequential circuits), choice of an algorithm within a number of existing test generation algorithms to apply is bound to vary from circuit t... To generate a test set for a given circuit (including both combinational and sequential circuits), choice of an algorithm within a number of existing test generation algorithms to apply is bound to vary from circuit to circuit. In this paper, the genetic algorithms are used to construct the models of existing test generation algorithms in making such choice more easily. Therefore, we may forecast the testability parameters of a circuit before using the real test generation algorithm. The results also can be used to evaluate the efficiency of the existing test generation algorithms. Experimental results are given to convince the readers of the truth and the usefulness of this approach. 展开更多
关键词 testABILITY GENETIC Algorithm forecasting EVALUATING test Generation.
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Study on Precipitation Forecast and Testing Methods of Numerical Forecast in Fuxin Area
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作者 Xu Zhang Ji Liu +1 位作者 Yue Gao Xiaotong Yang 《Journal of Geoscience and Environment Protection》 2017年第7期32-38,共7页
This research uses Japan facsimile data in May-September of 2011-2015 in Fumeng and Zhangwu County of Fuxin, Liaoning, China as the site selection for high altitude NECV circulation background, using statistical and s... This research uses Japan facsimile data in May-September of 2011-2015 in Fumeng and Zhangwu County of Fuxin, Liaoning, China as the site selection for high altitude NECV circulation background, using statistical and synoptic methods testing the combination of test and Analysis on Japanese numerical precipitation prediction and error. The prediction equation of cold vortex precipitation in the region is established by SPSS software. It is predicted whether the product predicts precipitation, water vapor condition and vertical velocity according to the Japanese numerical forecast. The results show that the fitting rate is 88% in the past 5 years, and the rate of cold vortex precipitation in the summer of 2016 is 89%. 展开更多
关键词 JAPAN FAX Map NORTHEAST COLD VORTEX Precipitation test forecasting Method
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A New Method for Forecasting the Life Test Data of Mechanical Products
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作者 ZHANG Huai-liang, TAN Guanjun, QIU Xian-yan College of Mechanical and Electrical Engineering Central South University Changsha 410083, P R. China 《International Journal of Plant Engineering and Management》 2001年第2期57-64,共8页
The model for forecasting the test data on mechanical products is established in the application of the grey system theories. A new formula of the background value is introduced into the model. The result of an exampl... The model for forecasting the test data on mechanical products is established in the application of the grey system theories. A new formula of the background value is introduced into the model. The result of an example shows the method can reduce test expense and enhance the precision of forecasting. 展开更多
关键词 mechanical product life test data forecast grey system theory
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中长期地震危险性概率预测中的统计检验方法Ⅱ:N-test和L-test方法 被引量:4
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作者 高朝军 蒋长胜 +1 位作者 韩立波 李艳娥 《地震》 CSCD 北大核心 2013年第1期47-55,共9页
本文介绍了国际"地震可预测性合作研究"CSEP计划中,用于地震概率预测模型检验的N-test和L-test方法的基本原理、发展动态。以地震活动平滑模型(smoothed seismicity model)在新疆天山中部地区的中长期预测结果为例,本文尝试使... 本文介绍了国际"地震可预测性合作研究"CSEP计划中,用于地震概率预测模型检验的N-test和L-test方法的基本原理、发展动态。以地震活动平滑模型(smoothed seismicity model)在新疆天山中部地区的中长期预测结果为例,本文尝试使用N-test和L-test统计检验方法对预测结果进行评价。结果表明,上述方法能够较好地评价预测结果,并有助于构建更为科学合理的地震预测模型及相关参数设置。 展开更多
关键词 地震概率预测模型 统计检验 N—test方法 L-test方法
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基于图像信息算法的2024年新疆乌什M_(S)7.1地震回溯性预测研究
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作者 袁伏全 黄浩 +2 位作者 徐玮阳 张晓清 刘兴盛 《地震研究》 北大核心 2026年第2期198-206,共9页
使用1970年以来新疆天山地震带及邻区的地震目录资料,基于图像信息(PI)算法,计算得到2016—2028年该地区逐年滑动的预测窗PI热点分布图像,并使用工作特征图表法(ROC)和R值评分法对PI算法的预测效能进行了检验。结果表明:①在2020—2024... 使用1970年以来新疆天山地震带及邻区的地震目录资料,基于图像信息(PI)算法,计算得到2016—2028年该地区逐年滑动的预测窗PI热点分布图像,并使用工作特征图表法(ROC)和R值评分法对PI算法的预测效能进行了检验。结果表明:①在2020—2024年回溯性预测图像中,2024年新疆乌什M_(S)7.1地震震中区域存在PI热点,具有较强的发震地点指示意义。②在5个回溯性预测时间窗(2016—2020年、2017—2021年、2018—2022年、2019—2023年、2020—2024年)内的PI热点图像演化过程中,乌什M_(S)7.1地震震中附近PI热点表现为“出现—逐步密集增强”,发震概率增大,该热点附近发震紧迫性和地震危险性增强。③ROC检验和R值评分显示,PI算法优于随机预测方法。④综合热点信息演化图像分析得到,南天山地震带的西南端强震危险性较高。 展开更多
关键词 乌什M_(S)7.1地震 PI算法 回溯性预测 地震热点 ROC检验
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徐州地震台同场地钻孔应变仪器预报效能对比分析
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作者 郝冉 刘冬冬 +4 位作者 高明智 张岑 何斌 董传磊 许炳 《大地测量与地球动力学》 北大核心 2026年第1期115-122,130,共9页
基于徐州地震台2种钻孔应变仪的观测数据,应用R值检验方法对2种仪器记录的趋势转折型异常、破年变型异常及速率型异常的预报效能进行评分计算,系统地对比分析同场地2套钻孔应变仪器的预报效能,明确二者在地震前兆监测中的互补性。结果表... 基于徐州地震台2种钻孔应变仪的观测数据,应用R值检验方法对2种仪器记录的趋势转折型异常、破年变型异常及速率型异常的预报效能进行评分计算,系统地对比分析同场地2套钻孔应变仪器的预报效能,明确二者在地震前兆监测中的互补性。结果表明,钻孔体应变仪对趋势转折型异常和破年变型异常的预报效能表现良好,适合捕捉与长期地质构造活动相关的地震前兆异常信号。钻孔分量应变仪在趋势转折型异常和速率型异常的预报中展现出较强的能力,更擅长捕捉地质体受力状态发生变化而产生的趋势转折前兆异常信号,对于区域应力应变快速变化的监测具有较高灵敏性。研究结果揭示了钻孔应变仪器在地震前兆监测中的效能差异,同时给出了二者在地震预报中的应用重点及优化方向。 展开更多
关键词 钻孔应变观测 R值检验方法 前兆异常 预报效能
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Change Characteristics and Forecast Research of Road Surface Temperature on Huyu Expressway (Hubei Section) 被引量:1
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作者 Cheng Dan Fu Xiaohui 《Meteorological and Environmental Research》 CAS 2017年第5期92-99,104,共9页
In this paper,the monitoring data of road surface temperature,air temperature,wind speed,wind direction,relative humidity and precipitation from the automatic weather stations of Hurongxi,Hanyi,Wuhuang and Huanghuang ... In this paper,the monitoring data of road surface temperature,air temperature,wind speed,wind direction,relative humidity and precipitation from the automatic weather stations of Hurongxi,Hanyi,Wuhuang and Huanghuang on Huyu expressway from June 2013 to August 2014 were used to investigate the change characteristics of different sections' road surface temperatures in different seasons and sky conditions. The forecast models of the maximum and minimum road surface temperatures were established on different sections by statistical analysis methods,and the forecast results were verified. The results showed that the road surface temperature and air temperature of Hurongxi,Hanyi,Wuhuang and Huanghuang displayed obvious diurnal variation,but the difference between the road surface temperature and air temperature was larger. Compared with the other three sections,the maximum difference between the road surface temperature and air temperature on Hurongxi increased in winter and decreased in summer overall. The road surface temperature was close to air temperature on Hurongxi after sunset on sunny to cloudy and overcast in winter,while less than air temperature on Hanyi,Wuhuang and Huanghuang. The air temperature was less than road surface temperature on the four sections on rainy day and significant on Hurongxi. In summer,the air temperature was less than road surface temperature on the four sections under three sky conditions and the difference between them in afternoon was the biggest on sunny to cloudy and overcast. The road surface temperature was very close to each other among the four sections in January,while which was rising with the decrease of altitude in April,July and October. The forecast result of the road surface temperature was close to actual result on Hurongxi and Huanghuang,so which can be for reference. But there were some big errors between the forecast result and actual result in several timings on Hanyi and Wuhuang,so the forecast result should be corrected for actual business work. 展开更多
关键词 ROAD surface TEMPERATURE Variation CHARACTERISTICS forecast model test
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Forecasting the Quasi-stationary Front Rainstorm in Southeast China Using the Synthetically Multilevel Analog Forecast Technology 被引量:1
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作者 Li Bo Zhao Si-Xiong Yao Zhi-Gang 《Atmospheric and Oceanic Science Letters》 2009年第1期68-72,共5页
The authors use numerical model integral products in a third level forecast of synthetically multi-level analog forecast technology.This is one of the strongest points of this study,which also includes the re-ducing m... The authors use numerical model integral products in a third level forecast of synthetically multi-level analog forecast technology.This is one of the strongest points of this study,which also includes the re-ducing mean vacant-forecast rate method,which pos-sesses many advantages with regard to filtering the analog term.Moreover,the similitude degree between samples is assessed using a combination of meteorological elements,which works better than that described using a single element in earlier analog forecast studies.Based on these techniques,the authors apply the model output,air sounding,surface observation and weather map data from 1990 to 2002 to perform an analog experiment of the quasi-stationary front rainstorm.The most important re-sults are as follows:(1) The forecast successful index is 0.36,and was improved after the forecast model was re-vised.(2) The forecast precise rate (0.59) and the lost-forecast rate (0.33) are also better than those of other methods.(3) Based on the model output data,the syn-thetically multilevel analog forecast technology can pro-duce more accurate forecasts of a quasi-stationary front rainstorm.(4) Optimal analog elements reveal that trig-gering mechanisms are located in the lower troposphere while upper level systems are more important in main-taining the phase of the rainstorm.These variables should be first taken into account in operational forecasts of the quasi-stationary front rainstorm.(5) In addition,experi-ments reveal that the position of the key zone is mainly decided by the position of the system causing the heavy rainfall. 展开更多
关键词 synthetically multilevel analog forecast technology quasi-stationary front rainstorm analog forecast experiment test of model capability forecast range
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The Obtaining and Verification of Meticulous Climate Forecast Product
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作者 ZHOU Xiao-yun LI Xiao-juan +1 位作者 XIE Ding-sheng LIANG Jian 《Meteorological and Environmental Research》 CAS 2011年第3期4-6,42,共4页
[Objective] The aim was to study the obtaining method of meticulous climate forecast product and test its forecast effect. [Method] Based on the national standard surface observation data and secondary data bank obtai... [Objective] The aim was to study the obtaining method of meticulous climate forecast product and test its forecast effect. [Method] Based on the national standard surface observation data and secondary data bank obtained by means of distance weight interpolation method, the model of climate forecast was established, and the timing, fixed-point and quantitative meticulous climate forecast of meteorological elements was obtained by using many forecast methods and artificial revision, finally the forecast effect was tested. [Result] At present, meticulous climate forecast system was used to predict the daily, five-day, ten-day, monthly, seasonal and annual variation of six meteorological elements (including average temperature, maximum temperature, minimum temperature, precipitation, average pressure and sunshine) in 10 meteorological stations in Guangzhou City. The forecast effect of meteorological elements in 10 stations in Guangzhou City from 2006 to 2010 was tested, and the average scores of monthly precipitation, average temperature, maximum temperature and minimum temperature were 75.0, 94.5, 98.6 and 88.9, respectively, while the scores of five-day meteorological elements were 77.1, 90.6, 90.1 and 82.8, which met the requirement of objective management of Guangdong Meteorological Observatory. [Conclusion] Meticulous climate forecast system could be widely used in the forecast of agricultural meteorological disasters and fixed-point forecast in large reservoir, new airport and nuclear power station. 展开更多
关键词 Meticulous Climate forecast Effect test China
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Establishment and Test of a Lightning Potential Prediction Index
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作者 Ou Jianfang Qi Haixia Wang Haitao 《Meteorological and Environmental Research》 CAS 2019年第5期51-54,58,共5页
The mesoscale forecasting model WRF is used to simulate two strong convective weather processes accompanied by lightning in Qinghai Province,and the simulated lightning potential index (LPI) and the observed lightning... The mesoscale forecasting model WRF is used to simulate two strong convective weather processes accompanied by lightning in Qinghai Province,and the simulated lightning potential index (LPI) and the observed lightning are compared.Finally,the application of LPI in another lightening case is examined.The results show that the simulated LPI corresponds well to the observed lightning in time.In terms of spatial distribution,the simulated LPI tends to be consistent with the observed lightning density,but there are some minor differences in the locations.Therefore,the LPI can be used to forecast lightning density. 展开更多
关键词 WRF model LIGHTNING forecast INDEX Analysis test
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Short-Term Precipitation Forecasting Rolling Update Correction Technology Based on Optimal Fusion Correction
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作者 Meijin Huang Qing Lin +4 位作者 Ning Pan Nengzhu Fan Tao Jiang Qianshan He Lingguang Huang 《Journal of Geoscience and Environment Protection》 2019年第3期145-159,共15页
In order to improve the availability of regional model precipitation forecast, this project intends to use the measured heavy rainfall data of dense automatic stations to carry out historical precipitation in the high... In order to improve the availability of regional model precipitation forecast, this project intends to use the measured heavy rainfall data of dense automatic stations to carry out historical precipitation in the high resolution: the Severe Weather Automatic Nowcast System (SWAN) quantitative precipitation forecast and the High-Resolution Rapid Refresh (HRRR) regional numerical model precipitation forecast in short-term nowcasting aging. Based on the error analysis, the grid fusion technology is used to establish the measured rainfall, HRRR regional model precipitation forecast, and optical flow radar quantitative precipitation forecast (QPF) three-source fusion correction scheme, comprehensively integrate the revised forecasting effect, adjust the fusion correction parameters, establish an optimal correction plan, generate a frozen rolling update revised product based on measured dense data and short-term forecast, and put it into business operation, and perform real-time effect rolling test evaluation on the forecast product. 展开更多
关键词 OPTIMAL FUSION CORRECTION Radar QPF Numerical Model SHORT-TERM Precipitation forecasting ROLLING test
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EMD及其扩展方法在水文学中的研究进展及应用综述 被引量:1
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作者 陈云飞 刘祖钰 +3 位作者 刘秀花 贺军奇 郑策 马延东 《灌溉排水学报》 2025年第2期101-112,共12页
受气候变化、生态演替以及人类活动的影响,水文序列蕴含了大量多界面交互叠加信息,使其过程表现出高度非线性与非平稳特征。因此,如何挖掘、分析水文序列中的隐藏信息及局部时变特征一直是水文学领域研究的热点和难点。经验模态分解(EMD... 受气候变化、生态演替以及人类活动的影响,水文序列蕴含了大量多界面交互叠加信息,使其过程表现出高度非线性与非平稳特征。因此,如何挖掘、分析水文序列中的隐藏信息及局部时变特征一直是水文学领域研究的热点和难点。经验模态分解(EMD)自提出以来便迅速受到各界学者们的广泛关注,近年来在水文领域中的应用更突显了其处理非线性、非平稳数据的优越性。本文梳理了EMD的基本理论、方法特性及现存问题,总结了5种发展较为成熟且应用广泛的EMD/类EMD扩展方法,包括希尔伯特-黄变换、集合经验模态分解、多元经验模态分解、极点对称模态分解及变分模态分解。随后通过水文序列的多时空尺度分析、趋势检验和模型预测3个方面,综述了EMD及其扩展方法的应用研究现状。最后,对其在水文学中的应用研究进行了展望,并就EMD的理论框架、水文变异性分析及区域多时空尺度研究提出了具体建议。 展开更多
关键词 数据挖掘 多时空尺度分析 水文变异性分析 趋势检验 水文预报
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基于多元线性回归的EA4T钢磨削表面残余应力预测
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作者 杨光 李峰 于国强 《机械设计与制造》 北大核心 2025年第5期137-140,144,共5页
对工件磨削期间的表面残余应力进行测试获得实验数据,通过数理统计的方法测定了各个磨削参数下得到的表面残余应力差异性,利用线性回归模型实现残余应力的预测;最后对磨削过程中机械应力的改变状态开展了全面分析。研究结果表明:增大磨... 对工件磨削期间的表面残余应力进行测试获得实验数据,通过数理统计的方法测定了各个磨削参数下得到的表面残余应力差异性,利用线性回归模型实现残余应力的预测;最后对磨削过程中机械应力的改变状态开展了全面分析。研究结果表明:增大磨削深度后,初始为拉应力作用的表层残余应力转变为压应力的状态,应力大小也跟磨削深度表现为正相关的特点。随着砂轮速度的提高,表面发生了残余应力的持续降低。采用回归分析方法得到工件表面的残余应力数据,通过F检验法实施判断结果符合高度显著条件。机械应力和磨削表面应力变化趋势相近,当磨削深度或进给速度增大时都发生了作用力升高的现象。该研究对提高刚表面磨削机加工精度以及表面质量调控具有很好的价值。 展开更多
关键词 磨削加工 残余应力 测试 线性回归 预测分析
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基于组合模型的风洞试验六元力预测
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作者 宋佳音 张林 周宏威 《自动化技术与应用》 2025年第9期6-11,共6页
风洞试验对于试验设备和场地具有较高要求,且耗时长,成本高,数据获取困难。为此提出基于组合模型对风洞试验六元力进行预测。首先利用SMOTE过采样方法对风洞试验小样本数据进行数据扩充,然后采用极限梯度提升算法(extreme gradient boos... 风洞试验对于试验设备和场地具有较高要求,且耗时长,成本高,数据获取困难。为此提出基于组合模型对风洞试验六元力进行预测。首先利用SMOTE过采样方法对风洞试验小样本数据进行数据扩充,然后采用极限梯度提升算法(extreme gradient boosting,XGBoost)、K最近邻算法(k-nearest neighbor,KNN)和多层感知器(multilayer perceptron,MLP)3个单一模型建立XGBoost-KNN-MLP组合模型。为克服权重带来的影响,采用人工免疫算法(artificial immune algorithm,AIA)对组合模型的权重系数进行优化建立AIA-XKM组合预测模型。预测效果以平均绝对误差(mean absolute error,MAE)、均方误差(mean square error,MSE)、决定系数(r-square,R2)和均方根误差(root mean squared error,RMSE)为评价指标。并与经典算法XGBoost、KNN、MLP、SVM、RNN构建的预测模型进行对比。实验结果表明,所提出的AIA-XKM组合预测模型在六元力预测中弥补了单一模型存在的不足,在预测精度和泛化能力中表现出更高性能。将该预测模型应用于风洞试验前,能够提前预测试验的输出数值,判断试验的可行性与准确性,提高风洞试验的成功率,减少无用试验。 展开更多
关键词 数据预测 小样本 组合模型 风洞试验
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分解-集成径流预测模型性能“高低”差异机理与特性分析 被引量:1
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作者 王庆杰 岳春芳 +1 位作者 刘长升 朱灵芝 《水电能源科学》 北大核心 2025年第6期1-5,18,共6页
分解-集成模型能显著提高预测精度,但部分模型不恰当地使用测试集数据,其高精度的预测结果备受质疑。基于数据分布特性分析技术评估分析后验试验框架(HE)和预测试验框架(FE)2类典型分解-集成模型的性能差异机理,以2个典型水库的月径流... 分解-集成模型能显著提高预测精度,但部分模型不恰当地使用测试集数据,其高精度的预测结果备受质疑。基于数据分布特性分析技术评估分析后验试验框架(HE)和预测试验框架(FE)2类典型分解-集成模型的性能差异机理,以2个典型水库的月径流预测为例,以误差逆传播神经网络(BP)、支持向量机(SVM)、随机森林(RF)为基准模型,以变分模态分解(VMD)和互补集合经验模态分解(CEEMD)为分解算法分别构建模型,在分析各类模型预测结果的基础上,综合利用高斯核密度估计、偏度、样本熵等技术识别各类模型训练集与测试集的数据分布特性。从预测精度看,HE训练集和测试集上的预测精度远高于单一模型;FE在训练集上与HE模型相近,在测试集上远低于单一模型。从训练集、测试集分布特性上看,训练集上单一模型的偏度值为2.03,而HE、FE模型各分解分量的偏度介于0~1.52之间;训练集、测试集的样本熵差异在单一模型上为0.13,在HE、FE模型各分解分量上分别介于0.01~0.25、0.47~1.18之间。HE使用整体分解方式,分解后训练数据的复杂程度低、代表性强,建立的模型拟合性能高、预测性能强;FE使用并行—分步分解方式,训练数据—测试数据间出现显著的协变量偏移,建立的模型拟合性能虽高但预测性能不达标。研究结果可为分解—集成预测建模的改进提供参考。 展开更多
关键词 分解集成 径流预测 端点效应 后验试验框架 预测试验框架
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长年限多沙河流电站压力钢管泥沙磨损试验与寿命预估研究 被引量:1
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作者 邱巍 彭梁 +4 位作者 严戴志 郑有全 余志顺 刘小兵 张力 《水电能源科学》 北大核心 2025年第6期172-174,193,共4页
针对龚嘴电站运行年限长达50余年,近年检测发现压力钢管因存在泥沙磨损导致管壁厚减薄潜在安全运行的隐患,开展了压力钢管沙水流动数值模拟以及泥沙磨损试验和预测研究,建立泥沙磨损预估数学模型,预估压力钢管寿命。研究表明,龚嘴水电... 针对龚嘴电站运行年限长达50余年,近年检测发现压力钢管因存在泥沙磨损导致管壁厚减薄潜在安全运行的隐患,开展了压力钢管沙水流动数值模拟以及泥沙磨损试验和预测研究,建立泥沙磨损预估数学模型,预估压力钢管寿命。研究表明,龚嘴水电站压力钢管明管段泥沙磨损,在汛期平均泥沙浓度2.5kg/m^(3)条件下,磨损率达1.392×10^(-4)mm/h,在平均泥沙浓度0.63kg/m^(3)条件下,磨损率为3.509×10^(-5)mm/h,若不考虑河流泥沙浓度有逐步增大趋势等其他影响因素的情况,按压力钢管设计要求和年平均泥沙浓度0.63 kg/m^(3)预估,理论上龚嘴水电站压力钢管明管段还能运行19年。但由于压力钢管还可能锈蚀,同时还会遇到河流泥沙浓度剧增的情况,建议要加强对管道系统壁厚的监测和日常维护。 展开更多
关键词 长年限 多沙电站 压力钢管 泥沙磨损试验 寿命预估
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TA11钛合金本构及铣削表面质量预测研究 被引量:1
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作者 侍中楼 杨湘杰 《精密成形工程》 北大核心 2025年第1期33-42,共10页
目的探明不同铣削参数对TA11钛合金铣削表面质量的影响规律,建立基于铣削参量的表面粗糙度预测模型,实现TA11钛合金铣削表面质量的预测。方法通过TA11钛合金在不同应变速率下的室温拉伸实验,构建TA11钛合金相关的JC本构模型,并基于此建... 目的探明不同铣削参数对TA11钛合金铣削表面质量的影响规律,建立基于铣削参量的表面粗糙度预测模型,实现TA11钛合金铣削表面质量的预测。方法通过TA11钛合金在不同应变速率下的室温拉伸实验,构建TA11钛合金相关的JC本构模型,并基于此建立铣削过程的有限元模型,通过与实验对比验证有限元模拟的准确性;通过正交实验设计结合单因素分析法,阐明不同铣削参数组合下的TA11钛合金表面粗糙度演化规律;最后基于多元线性回归法,建立基于铣削参量的表面粗糙度预测模型。结果分别建立了可真实反映TA11钛合金不同应变速率下应力-应变行为和损伤行为的JC本构模型与损伤模型,预测结果与实验结果吻合度较高;在铣削速度为5300 r/min、每齿进给量为0.04 mm/z、铣削深度为1 mm、铣削宽度为0.2 mm的实验条件下,铣削过程的有限元模拟结果与实验结果误差为11.83%;所建立的粗糙度预测模型拟合程度R2=0.963、显著性水平P<0.001,模型拟合度较高,具有统计学意义。结论所建立的JC本构模型和损伤模型能够较好地描述TA11钛合金在不同应变速率下的变形行为和损伤演化过程,基于此开展的铣削过程有限元模拟可反映铣削参量对TA11钛合金表面粗糙度的影响规律;所建立的表面粗糙度预测模型可为TA11钛合金铣削工艺方案的制订提供一定的工程指导。 展开更多
关键词 TA11钛合金 表面粗糙度 JC本构模型 有限元模拟 正交实验 预测模型
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帕金森病脑深部电刺激术后感染的相关因素
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作者 郑莞怡 刘元芬 +6 位作者 施宇婷 吴振兴 肖慧楠 黄仰发 林若兰 蒋日烽 薛蕴菁 《中国医药科学》 2025年第22期143-148,共6页
目的探讨帕金森病(PD)患者脑深部电刺激(DBS)术后发生感染的潜在相关因素。方法回顾性研究2017年11月至2023年4月福建医科大学附属协和医院接受DBS的120例PD患者,收集患者性别、年龄、病程、既往病史、血常规、并发症等临床资料,根据术... 目的探讨帕金森病(PD)患者脑深部电刺激(DBS)术后发生感染的潜在相关因素。方法回顾性研究2017年11月至2023年4月福建医科大学附属协和医院接受DBS的120例PD患者,收集患者性别、年龄、病程、既往病史、血常规、并发症等临床资料,根据术后是否发生感染,分为感染组和无感染组。采用单因素分析筛选术后感染发生的相关因素。多因素二元logistic回归用于分析术后感染发生的独立预测因子,并建立预测模型,绘制受试者操作特征(ROC)曲线,评估术后感染的预测效能。结果有30%(36/120)患者发生术后感染。感染组病程、中性粒细胞绝对数(术前)、C-反应蛋白(术后当天)、手术时长均显著高于无感染组,第一阶段局部麻醉合并头皮神经阻滞麻醉发生术后感染的比例显著低于第一阶段单纯局部麻醉的方式,差异有统计学意义(P<0.05)。多因素分析提示病程[OR=1.017,95%CI:1.000~1.034,P=0.046]、麻醉方式(OR=0.000,95%CI:0.000~0.828,P=0.046)和C-反应蛋白(术后当天)(OR=1.269,95%CI:1.029~1.565,P=0.026)为独立预测因子。预测模型预测术后感染的曲线下面积(AUC)为0.851,在最佳临界值下灵敏度为84.6%,特异度为76.3%。结论DBS术后发生感染的概率较高,C-反应蛋白(术后当天)、病程和麻醉方式是DBS治疗PD术后感染的独立预测指标,基于logistic回归的预测模型具有较高的预测性能。 展开更多
关键词 帕金森病 脑深部电刺激 感染 预测模型 血常规
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