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NI Multisim中三种交流电压信号源的区别 预览
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作者 李菁淋 王文虎 李杰林 《信息技术与信息化》 2019年第4期181-183,共3页
运用NI Multisim 虚拟仿真软件验证电子线路技术性能时,必然会应用虚拟软件中AC_POWER、AC_VOLTAGE、Function generator 等三种正弦信号之一作为输入信号源。借助T 型电阻网络反相比例运算放大电路的传输特性分析,理清了三种不同信号... 运用NI Multisim 虚拟仿真软件验证电子线路技术性能时,必然会应用虚拟软件中AC_POWER、AC_VOLTAGE、Function generator 等三种正弦信号之一作为输入信号源。借助T 型电阻网络反相比例运算放大电路的传输特性分析,理清了三种不同信号源的幅值关系,奠定了正确理解电子应用线路虚拟仿真的分析基础。 展开更多
关键词 NI MULTISIM 有效值 峰值 峰峰值
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Analysis of Similarities of Different Species of Boenninghausenia Plants by Common and Variant Peak Ratios Dual Indicator Sequence Method 预览
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作者 Nannan LONG Risha WEIZE +3 位作者 Hairong ZH Xiaoxia CAI Yuan LIU Ying LI 《药用植物研究(英文版)》 2019年第2期73-78,84共7页
[Objectives] To analyze the similarities of Boenninghausenia sessilicarpa Levl. and Boenninghausenia albiflora(Hook.) Meiss by the common and variant peak ratio dual indicator sequence method.[Methods] Four different ... [Objectives] To analyze the similarities of Boenninghausenia sessilicarpa Levl. and Boenninghausenia albiflora(Hook.) Meiss by the common and variant peak ratio dual indicator sequence method.[Methods] Four different solvents(petroleum ether, chloroform, ethyl acetate and methanol) were used to extract the chemical components of different polar regions of B. sessilicarpa and B. albiflora. UV-visible spectrophotometry(second derivative method) was used to collect the fingerprints of different solvent extracts, and common and variant peak peak ratios were analyzed for the absorption peak data.[Results] The common peak ratio and variant peak ratio data of ground parts of B. albiflora and B. sessilicarpa was S2∶S5(46.2(54.2, 62.5)), compared with the data of other groups, the common peak ratio was the largest, thus the components of ground parts of B. albiflora and B. sessilicarpa were closest and had the largest similarities;the common peak ratio and variant peak ratio data of the components extracted by chloroform from B. albiflora and B. sessilicarpa was Y2∶Y6(54.2(38.5, 46.2)), compared with the data of other groups, the variant peak ratio was the smallest, thus, the chemical components near the chloroform polarity of two kinds of medicinal materials had the largest similarities and smallest differences.[Conclusions] This method is simple and easy to operate, and the ultraviolet fingerprint data of four different polar organic solvent extracts are used for comprehensive analysis, and the results have high specificity and high accuracy. Besides, there are certain similarities and also differences between the chemical components of B. sessilicarpa and B. albiflora. It is expected to provide a new evaluation method for the variety quality of B. sessilicarpa and B. albiflora. 展开更多
关键词 Boenninghausenia albiflora (Hook.) Meiss Boenninghausenia sessilicarpa Levl. Ultraviolet FINGERPRINT COMMON PEAK RATIO VARIANT PEAK RATIO
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PEAK关系训练系统:孤独症语言障碍康复的新方法 预览
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作者 白晓宇 Tawanda S.Mutusva 祝卓宏 《心理科学进展》 CSSCI CSCD 北大核心 2019年第11期1896-1905,共10页
PEAK (Promoting the Emergence of Advanced Knowledge,促进高阶知识涌现)关系训练系统是全球首个同时整合了斯金纳的《言语行为》和后斯金纳主义的“关系框架理论”,促进孤独症谱系障碍(Autism spectrumdisorders, ASD)患者的语言、... PEAK (Promoting the Emergence of Advanced Knowledge,促进高阶知识涌现)关系训练系统是全球首个同时整合了斯金纳的《言语行为》和后斯金纳主义的“关系框架理论”,促进孤独症谱系障碍(Autism spectrumdisorders, ASD)患者的语言、学习、社交等核心技能发展的语言行为评估训练系统。截至2018 年底, PEAK 关系训练系统由以下4 个模块组成:直接训练模块、泛化模块、等价关系模块、功能转化模块。每一模块依据难易程度分别设置了184 个目标能力的评估方法及训练课程。已发表的多项实证研究表明, PEAK 关系训练系统打破了《语言行为里程碑评估及安置程序》(Verbal Behavior Milestones and Placement Program, VB-MAPP)对ASD 患者进行里程碑评估时出现的“天花板效应”,有望比VB-MAPP 提供更全面、高阶的语言行为评估体系。此外, PEAK 关系训练系统表现出的评估工具的信效度良好、多项效果研究显著、实践中易操作等特性,使其不仅适用于专业人员教学,未来在ASD 患者家庭干预模式中也有潜在的应用价值。 展开更多
关键词 孤独症谱系障碍 关系框架理论 PEAK 言语行为 VB-MAPP
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Study on Infrared Fingerprints of Different Sources of Yi Medicine Ebazema 预览
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作者 Hong YANG Ying LI +4 位作者 Risha WEIZE Jixiu SHEN Xuexue LI Yuan LIU Rui ZENG 《药用植物研究(英文版)》 2019年第1期46-50,共5页
[Objectives] To establish infrared fingerprints of different parts of Boenninghausenia albiflora(Hook.) Reichb.ex Meissn. and Boenninghausenia sessilicarpa Levl.(two sources of Yi medicine Ebazema) and analyze the sim... [Objectives] To establish infrared fingerprints of different parts of Boenninghausenia albiflora(Hook.) Reichb.ex Meissn. and Boenninghausenia sessilicarpa Levl.(two sources of Yi medicine Ebazema) and analyze the similarity between them. [Methods] The infrared fingerprints of powder of B. albiflora(Hook.) Reichb.ex Meissn. and B. sessilicarpa Levl. were measured, and the common peak rate and variation peak rate of six samples were calculated to establish the sequence analysis method of common peak rate. [Results] There was a very high common peak rate(≥81.3%) and a very low variation peak rate(≤15.4%) between S1 and S4 as well as S2 and S6. There was a low common peak rate between S1 and S3 as well as S3 and S4, and the common peak rate was 42.9% and 47.6% respectively. There was a low common peak rate(≤47.6%) and a high variation peak rate(≥100.0%) between S1 and S3 as well as S3 and S4. [Conclusions] The method is simple and convenient to operate, can quickly identify different parts used as medicine of B. albiflora(Hook.) Reichb.ex Meissn. and B. sessilicarpa Levl.(two sources of Yi medicine Ebazema), and provide a new method to judge whether the two are equivalent when being used as medicine and quality evaluation. 展开更多
关键词 Boenninghausenia albiflora(Hook.) Reichb.ex Meissn. Boenninghausenia sessilicarpa Levl. INFRARED FINGERPRINTS Common PEAK RATE Variation PEAK RATE
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Methods for obtaining characteristic γ-ray net peak count from interlaced overlap peak in HPGe γ-ray spectrometer system 预览
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作者 Yue-Li Song Feng-Qun Zhou +2 位作者 Yong Li Xiao-Jun Sun Peng-Fei Ji 《核技术:英文版》 SCIE CAS CSCD 2019年第1期73-78,共6页
For a characteristic γ-ray with interlaced overlap peak, and the case where its reliable and credible net count cannot be obtained using the current high-purity germa-nium (HPGe) multichannel γ-ray spectrum software... For a characteristic γ-ray with interlaced overlap peak, and the case where its reliable and credible net count cannot be obtained using the current high-purity germa-nium (HPGe) multichannel γ-ray spectrum software, two new methods are proposed herein to obtain the γ-ray net peak count from the interlaced overlap peak in the HPGe γ-ray spectrometer system, of which one is the symmetric conversion method based on Gaussian distribution and the other is where the energy average value of two close γ-rays is regarded as the γ-ray energy. The experimental results indicate that the two methods mentioned above are reliable and credible. This study is significant for the development of better γ-ray spectrum processing software for measuring complex γ-ray spectra concerning the nuclear reaction cross section, neutron activation analysis, and analysis of transuranium elements, using an HPGe detector. 展开更多
关键词 PEAK COUNT Interlaced OVERLAP PEAK Highpurity germanium (HPGe)γ-ray SPECTROMETER system
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Monitoring of brown stink bug (Hemiptera: Pentatomidae) population dynamics in corn to predict its abundanee using weather data
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作者 Xinzhi Ni Ted E. Cottrell +3 位作者 G. David Buntin Xianchun Li Wei Wang Hong Zhuang 《昆虫科学:英文版》 SCIE CAS CSCD 2019年第3期536-544,共9页
The brown stink bug (BSB), Euschistus servus (Say)(Hemiptera: Pentatomidae), is a serious economic pest of corn production in the southeastern United States. The BSB population dynamics was mon itored for 17 weeks fro... The brown stink bug (BSB), Euschistus servus (Say)(Hemiptera: Pentatomidae), is a serious economic pest of corn production in the southeastern United States. The BSB population dynamics was mon itored for 17 weeks from tasseling to preharvest of corn plants (i.e., late May to mid-September) using pheromone traps in three corn fields from 2005 to 2009. The trap data showed two peaks in early June and mid-August, respectively. The relationship between trap catch and pregrowing season weather data was examined using correlation and stepwise multiple factor regression analyses. Weather indices used for the analyses were accumulated growing degree day (AGDD), number of days with minimum temperature below 0℃(Subz), accumulated daily maximum (AMaxT) and minimum temperatures (AMinT) and rainfall (ARain). The weather indices were calculated with lower (10℃) and upper (35℃) as biological thresholds. The parameters used in regression analysis were seasonal abundance (or overall mean of BSB adult catch)(BSBm), number of BSB adults caught at a peak (PeakBSB), and peak week (Peakwk). The BSBm was negatively related to high temperature (AmaxT or AGDD) consistently, whereas IstPeakBSB was positively correlated to both ARain and Subz, irrespective of weather data durations (the first 4, 4.5, and 5 months). In contrast, the 7-month weather data (AGDD7) were negatively correlated to the BSBm only, but not correlated to the second PeakBSB. The 5-year monitoring study demonstrated that weather data can be used to predict the BSB abundance at its first peak in tasseling corn fields in the southeastern U.S. states. 展开更多
关键词 Euschistus servus first TRAP CATCH peak PHEROMONE TRAP CATCH population dynamics STEPWISE regression modeling weekly mean
瓦斯压力对煤体吸附特性及结构影响实验研究
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作者 徐佑林 吴旭坤 《煤矿安全》 CAS 北大核心 2019年第8期1-4,9共5页
为深入研究煤体在不同压力条件下吸附瓦斯特性及煤体孔隙结构变化特征,利用核磁共振(NMR)技术对煤体吸附瓦斯进行实验研究。实验结果表明:实验煤样的微小孔峰面积>中大孔峰面积>裂隙峰面积,表明煤样的微小孔最为发育,煤体孔径以... 为深入研究煤体在不同压力条件下吸附瓦斯特性及煤体孔隙结构变化特征,利用核磁共振(NMR)技术对煤体吸附瓦斯进行实验研究。实验结果表明:实验煤样的微小孔峰面积>中大孔峰面积>裂隙峰面积,表明煤样的微小孔最为发育,煤体孔径以微小孔为主,空隙之间的连通性不强,瓦斯不易流通;随着压力的增加,当瓦斯压力达到一定程度后,煤体会产生新的孔隙,微小孔隙相连通构成了微孔或者中孔,中孔相互连通形成了裂隙,为下一步解吸瓦斯的流通提供了条件,出现瞬时的瓦斯快速解吸;煤样瓦斯吸附解吸特征按照峰值前后分为上升阶段、变化剧烈阶段和基本不变阶段,总体规律上,煤体瓦斯吸附量随着瓦斯压力的增大而增加;在不同的瓦斯压力作用下,核磁共振T2谱图核磁信号幅度发生显著变化,T2谱图分布面积与瓦斯压力呈线性关系逐渐增长,即煤体孔隙度随瓦斯压力增加而增加。 展开更多
关键词 瓦斯压力 NMR T2谱图 峰值 吸附特性 煤体结构
Modified scaled distance regression analysis approach for prediction of blast-induced ground vibration in multi-hole blasting 预览
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作者 Hemant Agrawal A.K.Mishra 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第1期202-207,共6页
The blast-induced ground vibration prediction using scaled distance regression analysis is one of the most popular methods employed by engineers for many decades.It uses the maximum charge per delay and distance of mo... The blast-induced ground vibration prediction using scaled distance regression analysis is one of the most popular methods employed by engineers for many decades.It uses the maximum charge per delay and distance of monitoring as the major factors for predicting the peak particle velocity(PPV).It is established that the PPV is caused by the maximum charge per delay which varies with the distance of monitoring and site geology.While conducting a production blasting,the waves induced by blasting of different holes interfere destructively with each other,which may result in higher PPV than the predicted value with scaled distance regression analysis.This phenomenon of interference/superimposition of waves is not considered while using scaled distance regression analysis.In this paper,an attempt has been made to compare the predicted values of blast-induced ground vibration using multi-hole trial blasting with single-hole blasting in an opencast coal mine under the same geological condition.Further,the modified prediction equation for the multi-hole trial blasting was obtained using single-hole regression analysis.The error between predicted and actual values of multi-hole blast-induced ground vibration was found to be reduced by 8.5%. 展开更多
关键词 Peak particle velocity(PPV) Blast-induced ground vibration Scaled distance regression analysis Wave SUPERIMPOSITION SINGLE-HOLE BLASTING
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Silicon on Insulator with Highly Uniform Top Si Fabricated by H/He Coimplantation
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作者 苏鑫 高楠 +3 位作者 陈猛 徐洪涛 魏星 狄增峰 《中国物理快报:英文版》 SCIE CAS CSCD 2019年第6期103-106,共4页
Silicon on insulator with highly uniform top Si is fabricated by co-implantation of H+and He+ions. Compared with the conventional ion-slicing process with H implantation only, the co-implanted specimens whose He depth... Silicon on insulator with highly uniform top Si is fabricated by co-implantation of H+and He+ions. Compared with the conventional ion-slicing process with H implantation only, the co-implanted specimens whose He depth is deeper than H profile have the top Si layer with better uniformity after splitting. In addition, the splitting occurs at the position that the maximum concentration peak of H overlaps with the secondary concentration peak of He after annealing. It is suggested that the H/He co-implantation technology is a promising approach for fabricating fully depleted silicon on insulator. 展开更多
关键词 Silicon on INSULATOR H/He Coimplantation SECONDARY concentration PEAK
The impact of coastal reclamation on tidal and storm surge level in Sanmen Bay,China 预览
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作者 YANG Wankang FENG Xingru YIN Baoshu 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第6期1971-1982,共12页
In recent years,fast economic development demands for more land use and thus many reclamation projects are initiated around the Sanmen Bay,Zhejiang,SE China in the East China Sea,for which tidal and storm surge levels... In recent years,fast economic development demands for more land use and thus many reclamation projects are initiated around the Sanmen Bay,Zhejiang,SE China in the East China Sea,for which tidal and storm surge levels are reassessed.A two-dimensional numerical model based on an advanced circulation model(ADCIRC)was applied to evaluate the impact of reclamation projects on tidal and storm surge levels in the bay.The results show that the shoreline relocation and topographic change had opposite effects on tidal heights.Shoreline relocation decreased the tidal amplitude,while siltation caused topographic change and increased the amplitude.Such variations of the amplitude were significant in the top areas of Sanmen Bay.Three types of typhoon paths were selected for a case study to investigate the impacts of shoreline relocation and topographic change on storm surge level.Results show that the maximum increase in storm surge level due to shoreline relocation was less than 0.06 m.The rise of peak surge level due to the change of topography was significant and the peak surge level rose when siltation increased.The maximum surge level rise occurred in the path of northwest landing typhoons,which exceeded 0.24 m at the top of the bay.The rise in peak surge level can potentially lead to severe damages and losses in Sanmen Bay and more attention needs to be paid to this problem of shoreline change in the future. 展开更多
关键词 Sanmen BAY RECLAMATION project TIDAL height peak SURGE LEVEL
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Erosion and transport mechanisms of mine waste along gullies
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作者 ZHU Xing-hua CUI Yi-fei +2 位作者 PENG Jian-bing JIANG Cheng GUO Wei-long 《山地科学学报:英文版》 SCIE CSCD 2019年第2期402-413,共12页
Mine waste debris flows continue to occur in China, and the disaster prevention and mitigation of these flows faces severe challenges since the mechanisms determining erosion and transport of mine waste along gullies ... Mine waste debris flows continue to occur in China, and the disaster prevention and mitigation of these flows faces severe challenges since the mechanisms determining erosion and transport of mine waste along gullies are not yet fully understood. The erosion and delivery process of mine waste heaps was reproduced through flume experiments with the method based on field survey data of the Daxicha mine waste debris flow gully in the Xiaoqinling gold mining area. The results showed that the erosion and movement of mine wastes could be divided into three modes: minimal sediment movement, sediment sorting and delivery, and a large amount of sediment transfer. Moreover, there was an obvious amplification effect on peak discharge along with the formation and failure of temporary landslide dams during the erosion process. The correlation between the coefficient of peak discharge amplification and three dimensionless influencing factors, flume gradient, dimensionless volume, and dimensionless particle size, were comprehensively analyzed. An empirical formula for the coefficient of peak discharge amplification was proposed and verified based on 16 sets of experimental data. These preliminary results can provide a scientific reference for future research on disaster prevention and mitigation of mine waste debris flows. 展开更多
关键词 Mine waste DEBRIS flow EROSION and transport LANDSLIDE dam PEAK discharge AMPLIFICATION
Automatic de-noising and recognition algorithm for drilling fluid pulse signal 预览
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作者 HU Yongjian HUANG Yanfu LI Xianyi 《石油勘探与开发:英文版》 2019年第2期393-400,共8页
Wavelet forced de-noising algorithm is suitable for denoising of unsteady drilling fluid pulse signal, including baseline drift rectification and two-stage de-noising processing of frame synchronization signal and ins... Wavelet forced de-noising algorithm is suitable for denoising of unsteady drilling fluid pulse signal, including baseline drift rectification and two-stage de-noising processing of frame synchronization signal and instruction signal. Two-stage de-noising processing can reduce the impact of baseline drift and determine automatic peak detection threshold range for signal recognition by distinguishing different features of frame synchronization pulse and instruction pulse. Rising and falling edge relative protruding threshold is defined for peak detection in signal recognition, which can make full use of the degree of the signal peak change and detect peaks flexibly with rising and falling edge relative protruding threshold combination. A synchronous decoding method was designed to reduce position uncertainty of the frame synchronization pulse and eliminate the accumulative error of time base drift, which determines the first instruction pulse position according to position of the frame synchronization pulse and decodes subsequent instruction pulse by taking current instruction pulse as new bit synchronization pulse. Special tool software was developed to tune algorithm parameters, which has a decoding success rate of about 95% for the universal coded signals. For the special coded signals with check byte, decoding success rate using the automatic threshold adjustment algorithm is as high as 99%. 展开更多
关键词 drilling fluid pulse SIGNAL SIGNAL processing DECODING success rate AUTOMATIC DE-NOISING and recognition wavelet FORCED DE-NOISING peak detection SYNCHRONOUS DECODING
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An overview of the development history and technical progress of China's coal-fired power industry
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作者 Weiliang WANG Zheng LI +3 位作者 Junfu LYU Hai ZHANG Guangxi YUE Weidou NI 《能源前沿:英文版》 CSCD 2019年第3期417-426,共10页
As the main power source of China, coalfired power industry has achieved a great progress in installed capacity, manufacturing technologies, thermal efficiency, as well as pollutant control during the past century. Wi... As the main power source of China, coalfired power industry has achieved a great progress in installed capacity, manufacturing technologies, thermal efficiency, as well as pollutant control during the past century. With the fast development of renewable energies, coal-fired power industry is experiencing a strategic transformation. To specify the development of coal-fired power industry, its development history is reviewed and the technical progresses on aspects of thermal efficiency, pollutants control and peaking shaving capacity are discussed. It is concluded that the role of China's coal-fired power source would be transformed from the dominant position to a base position in power source structure. Considering the sustainable development of coal-fired power industry in energy conservation, emission control, and utilization of renewable energies, it is suggested that the national average thermal efficiency should be improved by continual up-gradation of units by using advanced technologies and eliminating outdated capacity. Moreover, the emission standard of air pollutants should not be stricter any more in coal-fired power industry. Furthermore, the huge amount of combined heat and power (CHP) coal-fired units should be operated in a decoupled way, so as to release more than 350 GW regulation capacity for the grid to accept more renewable energy power. 展开更多
关键词 coal-fired power development strategy eliminating outdated capacity PEAK SHAVING emission reduction RENEWABLE energy
Practical assessment of rock damage due to blasting 预览
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作者 Jhon Silva Tristan Worsey Braden Lusk 《矿业科学技术学报:英文版》 CSCD 2019年第3期379-385,共7页
Blasting is the most cost effective methodology to break rock for mining or civil engineering applications.A good production blast will break only the rock that is needed to be removed,leaving the host rock with minim... Blasting is the most cost effective methodology to break rock for mining or civil engineering applications.A good production blast will break only the rock that is needed to be removed,leaving the host rock with minimal damage.The control of rock damage due to blasting is very important when it comes to mine or construction design,safety,and cost.Damage to the host rock due to a production blast could result in failures,overbreak and unstable ground.Knowing how far the fractures generated by a production blast will go into the host rock is a valuable tool for engineers to design a safe highwall while keeping the actual excavation close to the design.Currently,there are several methods available to predict damage due to blasting.The accuracy of many of these methods is questionable,and in most cases,the methodologies over predict the results.This often leads to inefficient mines and poor construction works.When the current methodologies are reviewed,each one presents sound approaches,but in many cases they also lack consideration of other variables that,according to the authors,need to be included when predicting blast damage.This paper presents a practical methodology to assess the rock damage from blasting by combining other methodologies.The proposed method allows consideration of more variables when compared to available methods,resulting in a more accurate rock damage assessment.The method uses the estimation of the generated levels of peak particle velocity with the distance from a production blast presented by Persson and Holmberg,the peak particle velocity damage ranges proposed by Forsyth and the relationship between the static compressive strength and dynamic compressive strength of rocks from Liu.The new methodology was validated using the data published in a large-scale study performed in granite by Siskind. 展开更多
关键词 BLASTING FRACTURE FRACTURE EXTENSION PEAK particle VELOCITY
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Quality monitoring and biases estimation of BOC navigation signals 预览
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作者 ZHAO Hongwei ZHANG Zichun +1 位作者 LUO Xianzhi WANG Qiuping 《系统工程与电子技术:英文版》 SCIE EI CSCD 2019年第3期474-484,共11页
Many safety-critical applications that utilize the global navigation satellite system (GNSS) demand highly accurate positioning information, as well as highly integrity and reliability. Due to GNSS signals are easily ... Many safety-critical applications that utilize the global navigation satellite system (GNSS) demand highly accurate positioning information, as well as highly integrity and reliability. Due to GNSS signals are easily distorted by the interferences or disturbances, the signal quality monitoring (SQM) is necessary to detect the presence of dangerous signal distortions. In this paper, we developed an SQM software for binary offset carrier (BOC) modulated navigation signals. Firstly, the models of BOC signal with ideal and distortion are presented respectively. Then the architecture of SQM software is proposed. Moreover, the effect of the white gaussian noise (WGN) and the front-end filter on the correlation peak of the receiver is analyzed. Finally, the biases induced by the signal distortion are evaluated. The experiments simulate the relationships between the code phase shift and the normalized correlation value in the case of the signal digital distortion and the analog distortion. The simulation results demonstrate that the proposed SQM method can effectively monitor the signal distortion and accurately estimate the correlation peak deviation caused by the distortion. 展开更多
关键词 SIGNAL quality monitoring (SQM) binary OFFSET carrier (BOC) modulation biases estimation SIGNAL DISTORTION correlation peak
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Evaluation of a traditional method for peak flow discharge estimation for floods in the Wenchuan Earthquake area,Sichuan Province,China
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作者 GUO Xiao-jun CUI Peng +3 位作者 LI Yong LIU Jin-feng GE Yong-gang WANG Ci-de 《山地科学学报:英文版》 SCIE CSCD 2019年第3期641-656,共16页
Peak discharge of flood in small mountainous watershed is usually calculated using the 'Rainstorm–runoff calculation method in small watersheds in Sichuan Province'(RRM). This study evaluated the RRM calculat... Peak discharge of flood in small mountainous watershed is usually calculated using the 'Rainstorm–runoff calculation method in small watersheds in Sichuan Province'(RRM). This study evaluated the RRM calculation using real-time monitored rainfall and hydrologic data from a small watershed in the Wenchuan Earthquake area of Sichuan Province, China. The results indicated that the discharge values given by the RRM are commonly overestimating the measured discharge. The overestimation rate was discussed and empirical equations were proposed for improving RRM estimations, based on the relationship between calculated and measured discharge values at different watershed scales(2, 30, and 40 km2), under different rainfall probabilities(0.97–0.5, 0.5–0.2, and 0.2–0.002), and for different rainfall durations(0–6, 6–24, and >24 h). The results of this study help contribute to the understanding of water floods formation and help provide more accurate estimations of peak flow discharge in small watersheds in the Wenchuan Earthquake area. 展开更多
关键词 RAINFALL RUNOFF yield INFLUX PEAK DISCHARGE WENCHUAN Earthquake area
弱胶结砂岩破坏规律及其声发射特性试验研究
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作者 任建喜 景帅 刘朝科 《煤炭技术》 CAS 2019年第6期1-4,共4页
为探究煤矿巷道软弱围岩的变形规律,以彬长矿区某矿为研究对象,研究其顶板弱胶结砂岩在饱水状态下的三轴-声发射特性,分析其塑性变形破坏规律和不同应力阶段声发射特征,得到饱水弱胶结砂岩破坏过程中声发射演化规律。分析结果可为预测... 为探究煤矿巷道软弱围岩的变形规律,以彬长矿区某矿为研究对象,研究其顶板弱胶结砂岩在饱水状态下的三轴-声发射特性,分析其塑性变形破坏规律和不同应力阶段声发射特征,得到饱水弱胶结砂岩破坏过程中声发射演化规律。分析结果可为预测弱胶结砂岩变形破坏趋势提供理论依据,为控制同类砂岩顶板变形提供可行性方法。 展开更多
关键词 弱胶结砂岩 围压 声发射 残余强度 峰值
区域、区位与区别:哈尔滨百年发展史中的三次转型与三次高峰 预览
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作者 高龙彬 《北华大学学报:社会科学版》 2019年第1期61-66,共6页
作为一个区域的哈尔滨,因为不同时期的不同区位,在历史上的作用大有区别。在百年发展中,哈尔滨经历了三次转型:从松花江边的农业聚落、铁路村落到近代城市,从铁路附属地到自立自主以及从工业主导到多元成长的"蝶变"。伴随三... 作为一个区域的哈尔滨,因为不同时期的不同区位,在历史上的作用大有区别。在百年发展中,哈尔滨经历了三次转型:从松花江边的农业聚落、铁路村落到近代城市,从铁路附属地到自立自主以及从工业主导到多元成长的"蝶变"。伴随三次城市转型,哈尔滨出现了三次发展高峰。三次转型与高峰中,哈尔滨的变化都与俄国(苏联,俄罗斯)关系密切。这也是中国与俄国的一个博弈过程。 展开更多
关键词 哈尔滨 区位 转型 高峰 东北全面振兴 中俄关系
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武甲煤矿3101综采工作面支承压力分布规律 预览
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作者 杨建龙 《煤》 2019年第6期27-28,49共3页
综采工作面开采过程中,在煤壁的前方通常会出现超前支承压力,其峰值产生的位置与大小,将对工作面顶板的控制和支架的受力产生直接的影响。文章以武甲煤矿3101工作面的煤层赋存条件为工程背景,分析了各因素对支承压力峰值位置的影响规律... 综采工作面开采过程中,在煤壁的前方通常会出现超前支承压力,其峰值产生的位置与大小,将对工作面顶板的控制和支架的受力产生直接的影响。文章以武甲煤矿3101工作面的煤层赋存条件为工程背景,分析了各因素对支承压力峰值位置的影响规律,并利用理论计算和回归分析法,确定了支承压力的峰值位置和大小以及影响范围,达到了有效地保障工作面生产安全的目的。 展开更多
关键词 工作面 煤壁 支承压力 峰值 影响范围
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Different Flooding Behaviors Due to Varied Urbanization Levels within River Basin: A Case Study from the Xiang River Basin,China
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作者 Juan Du Linlin Cheng +2 位作者 Qiang Zhang Yumeng Yang Wei Xu 《国际灾害风险科学学报:英文版》 CSCD 2019年第1期89-102,共14页
Booming urbanization due to a fast-growing population results in more impervious areas, less infiltration,and hence greater flood peak and runoff. Clear understanding of flood responses in regions with different level... Booming urbanization due to a fast-growing population results in more impervious areas, less infiltration,and hence greater flood peak and runoff. Clear understanding of flood responses in regions with different levels and expansions of urbanization is of great importance for regional urban planning. In this study, comparison of flooding responses to urbanization processes in terms of flood peak and runoff volume in the upper, middle,and lower Xiang River Basin(XRB), China, was carried out using the Hydrologic Engineering Center-Hydrologic Modeling System(HEC-HMS) model. From 2005 to 2015, urbanization level and intensity were higher in the lower XRB compared to the upper and middle XRB, and the overall expansion rate of urban areas was 112.8%.Modeling results by the HEC-HMS model indicate elevated flood peak discharges and volumes due to fast urbanization in the XRB from the 1980 s to 2015. This rapid increase is particularly the case in the lower XRB. The study also revealed different hydrological responses of flood regimes—urbanization tends to have larger impacts on peak flood flow rather than on flood volume in the lowerXRB, which further corroborated urbanization-induced intensifying flood processes in terms of peak flood flow.Urbanization has increasing impacts on flood volume from the upper to the lower XRB, which can be attributed to accumulated runoff down the river system. This study provides a reference for basin-wide land use and urban planning as well as flood hazard mitigation. 展开更多
关键词 FLOOD volume FLOODING processes HECHMS PEAK FLOOD flow URBANIZATION level Xiang River Basin China
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