期刊文献+
共找到1,336篇文章
< 1 2 67 >
每页显示 20 50 100
Failure mechanism and infrared radiation characteristic of hard siltstone induced by stratification effect 被引量:1
1
作者 CHENG Yun SONG Zhanping +2 位作者 XU Zhiwei YANG Tengtian TIAN Xiaoxu 《Journal of Mountain Science》 SCIE CSCD 2024年第3期1058-1074,共17页
The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and tempora... The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and temporal damage mechanism of hard siltstone. The uniaxial compression tests, coupled with acoustic emission(AE) and infrared radiation temperature(IRT) were conducted on siltstones with different stratification effects. The results revealed that the stratigraphic structure significantly affects the stress-strain response and strength degradation characteristics. The mechanical parameters exhibit anisotropy characteristics, and the stratification effect exhibits a negative correlation with the cracking stress and peak stress. The failure modes caused by the stratification effect show remarkable anisotropic features, including splitting failure(Ⅰ: 0°-22.50°, Ⅱ: 90°), composite failure(45°), and shearing failure(67.50°). The AE temporal sequences demonstrate a stepwise response characteristic to the loading stress level. The AE intensity indicates that the stress sensitivity of shearing failure and composite failure is generally greater than that of splitting failure. The IRT field has spatiotemporal migration and progressive dissimilation with stress loading and its dissimilation degree increases under higher stress levels. The stronger the stratification effect, the greater the dissimilation degree of the IRT field. The abnormal characteristic points of average infrared radiation temperature(AIRT) variance at local stress drop and peak stress can be used as early and late precursors to identify fracture instability. Theoretical analysis shows that the competitive relationship between compaction strengthening and fracturing damage intensifies the dissimilation of the infrared thermal field for an increasing stress level. The present study provides a theoretical reference for disaster warnings in hard sedimentary rock mass. 展开更多
关键词 Hard siltstone Failure mechanism Stratification effect Infrared radiation characteristic Temporal-damage mechanism DISSIMILATION
下载PDF
Quantitative description of infrared radiation characteristics for solid materials subjected to external loading 被引量:2
2
作者 王芳 李英骏 +1 位作者 饶秋华 唐炼 《Journal of Central South University》 SCIE EI CAS 2009年第6期1022-1027,共6页
Based on the thermodynamics theory and physical micro-properties of solid materials subjected to external loading at room temperature,a formula of calculating temperature difference of infrared radiation in terms of t... Based on the thermodynamics theory and physical micro-properties of solid materials subjected to external loading at room temperature,a formula of calculating temperature difference of infrared radiation in terms of the sum of three principal strains was deduced to quantitatively investigate the infrared radiation characteristics in test. Two typical specimens,the three-point bending beam and the disc pressed in diameter,were tested and their principal strains were calculated by finite element method in order to obtain the temperature differences of infrared radiation. Numerical results are in a good agreement with test results,which verifies the validity of the formula of calculating temperature differences of infrared radiation and the model of quantitatively describing the infrared radiation characteristics of solid materials,and reveals the corresponding inner physical mechanism. 展开更多
关键词 Infrared radiation characteristics thermodynamics analysis numerical simulation strain tensor
下载PDF
Quantitative description of infrared radiation characteristics of preflawed sandstone during fracturing process 被引量:2
3
作者 Ke Zhang Xianghua Liu +1 位作者 Yulong Chen Heming Cheng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2021年第1期131-142,共12页
Previous studies show that infrared radiation temperature(IRT)abnormalities are always accompanied by the crack development in rocks under external loads.In this context,experiments were conducted on preflawed sandsto... Previous studies show that infrared radiation temperature(IRT)abnormalities are always accompanied by the crack development in rocks under external loads.In this context,experiments were conducted on preflawed sandstone to investigate the infrared radiation characteristics during failure process.Two indicators were defined herein,i.e.coefficient of variation of IRT(CVIRT)and skewness of IRT(SIRT).The regression analysis shows that the IRT probability distributions during loading process fit the Gaussian model.The variations in the CVIRT are characterized by four stages:primary stage,steady stage,accelerating stage and post-peak stage.Besides,the variations in the SIRT are divided into three stages:primary stage,steady stage and failure and post-peak stage.The precursor point for preflawed rock failure is identified based on the CVIRTetime curve,with average precursor point of 83%of the peak stress.Compared with other IRT indicators,the proposed two IRT indicators have higher sensitivity to IRT abnormalities during failure process.Furthermore,the connection between the IRT indicators and the rock fracturing was investigated to interpret the IRT indicator abnormalities.Based on the Verhulst inverse function,a new quantitative model was presented to describe the primary stage,steady stage and accelerating stage of the CVIRTetime curve.The results obtained in this study can provide early-warning information for rock failure prediction. 展开更多
关键词 Remote sensing rock mechanics Infrared radiation characteristics STATISTICS Precursor point Verhulst inverse model
下载PDF
Improvement of breakdown characteristics of an A1GaN/GaN HEMT with a U-type gate foot for millimeter-wave power application 被引量:1
4
作者 孔欣 魏珂 +1 位作者 刘果果 刘新宇 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第12期531-537,共7页
In this study, the physics-based device simulation tool Silvaco ATLAS is used to characterize the electrical properties of an AlGaN/GaN high electron mobility transistor (HEMT) with a U-type gate foot. The U-gate Al... In this study, the physics-based device simulation tool Silvaco ATLAS is used to characterize the electrical properties of an AlGaN/GaN high electron mobility transistor (HEMT) with a U-type gate foot. The U-gate AlGaN/GaN HEMT mainly features a gradually changed sidewall angle, which effectively mitigates the electric field in the channel, thus obtaining enhanced off-state breakdown characteristics. At the same time, only a small additional gate capacitance and decreased gate resistance ensure excellent RF characteristics for the U-gate device. U-gate AlGaN/GaN HEMTs are feasible through adjusting the etching conditions of an inductively coupled plasma system, without introducing any extra process steps. The simulation results are confirmed by experimental measurements. These features indicate that U-gate A1GaN/GaN HEMTs might be promising candidates for use in millimeter-wave power applications. 展开更多
关键词 AlGaN/GaN HEMT breakdown characteristics millimeter-wave U-type gate foot
下载PDF
Radiation Characteristics of a Novel µNegative Metamaterial Spiral Resonator Antenna at the 2.4 GHz 被引量:1
5
作者 Mochamad Yunus Fitri Yuli Zulkifli Eko Tjipto Rahardjo 《Open Journal of Antennas and Propagation》 2016年第1期1-11,共11页
A μ negative metamaterial using spiral resonator (SR) with an electromagnetically coupled (EMC) feeding system is proposed as a novel antenna structure. The proposed antenna is designed and fabricated on a FR4 dielec... A μ negative metamaterial using spiral resonator (SR) with an electromagnetically coupled (EMC) feeding system is proposed as a novel antenna structure. The proposed antenna is designed and fabricated on a FR4 dielectric substrate with a thickness of 1.6 mm and relative permittivity of 4.0 to achieve its radiation characteristic. The antenna is operated at frequency 2.4 GHz. To improve the antenna gain, a matching circuit is inserted into the feed line. The &micro;negative metamaterial is achieved by using a spiral resonator with spiral numbers N = 3, 5, 7, and 10. It is found that the negative imaginary part tends to shift leftward as the value of N increases. The simulation result of the proposed antenna structure with spiral number N = 3, strip width w = 3.1 mm, and gap width s = 0.5 mm provides the best performance with S11 = -15 dB, VSWR < 2 bandwidth of 30 MHz and gain of –0.5 dB at frequency of 2.43 GHz. The proposed antenna with matching circuit provides the antenna gain of 2.21 dB, which is better than that without the matching circuit. The dimensions of the proposed antenna are reduced by 53% compared with those of the conventional patch. Both the simulation and measurement results of the radiation characteristics of the proposed antenna show good agreement. 展开更多
关键词 radiation characteristics µ Negative Metamaterial Spiral Antenna
下载PDF
OBSERVATIONAL STUDY ON THE CHARACTERISTICS OF THE RADIATION AND SURFACE ATMOSPHERIC BOUNDARY LAYER OVER ANTARCTICA 被引量:1
6
作者 卞林根 陆龙骅 贾朋群 《中国气象科学研究院年报》 1996年第1期68-76,共9页
OBSERVATIONALSTUDYONTHECHARACTERISTICSOFTHERADIATIONANDSURFACEATMOSPHERICBOUNDARYLAYEROVERANTARCTICA¥BianLin... OBSERVATIONALSTUDYONTHECHARACTERISTICSOFTHERADIATIONANDSURFACEATMOSPHERICBOUNDARYLAYEROVERANTARCTICA¥BianLingen(卞林根).LuLonghu... 展开更多
关键词 林根 SURFACE ATMOSPHERIC LAYER OVER BOUNDARY radiation characteristicS OF 陆龙 AND
下载PDF
TIME-DOMAIN RADIATION CHARACTERISTICS OF V-DIPOLE ARRAYS
7
作者 王均宏 《Journal of Electronics(China)》 1993年第4期289-297,共9页
The time-domain radiation characteristics of a three V-dipole array have been stud-ied by direct time-domain method.Some valuable results are obtained.
关键词 V-dipole Array radiation characteristic Time-stepping approach
下载PDF
A study of flames with millimeter-wave radiation
8
作者 Jing-ran Xu Ru Peng +2 位作者 Chen-guang Zhu Xiao Xie Chen-guang Yan 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第4期876-882,共7页
It is a valuable issue to explore whether a flame can radiate microwaves,in spite of the electric field formed in the flame.Presented herein is an experimental study on a series of flames with millimeterwave radiation... It is a valuable issue to explore whether a flame can radiate microwaves,in spite of the electric field formed in the flame.Presented herein is an experimental study on a series of flames with millimeterwave radiation in the combustion of pyrotechnic films.The pyrotechnic films were composed of ultrafine red phosphorus(P),sodium nitrate(NaNO_3),Polyvinyl Alcohol(PVA) and some additives such as chopped carbon fibers(CFs) and aluminized glass fibers(GFs).The combustion temperatures and millimeter-wave radiation signals of the flames were measured,the millimeter-wave emissivity and spectral radiant exitance were calculated to describe the millimeter-wave radiation intensity.The results demonstrate that the flame of the pyrotechnic films based on P/NaNO_3/CFs can radiate millimeter waves,and different materials and their proportion have a great effect on the millimeter-wave radiation intensity. 展开更多
关键词 COMBUSTION FLAME PYROTECHNICS millimeter-wave radiation
下载PDF
Radiation Characteristics of the Reflector Antenna with Random Perforated Holes
9
作者 董涛 徐晓文 肖疆 《Journal of Beijing Institute of Technology》 EI CAS 2004年第4期378-380,共3页
The radiation characteristics of a doubly curved shaped reflector antenna with random holes is analyzed by physical optics (PO) method, and the probability model of the random holes and its numerical realization metho... The radiation characteristics of a doubly curved shaped reflector antenna with random holes is analyzed by physical optics (PO) method, and the probability model of the random holes and its numerical realization method are presented. The radiation patterns show that in the azimuth plane the peak sidelobe level becomes much higher as the reflector surface with random holes. The simulation results can provide a theoretical guidance for the radar attackers. 展开更多
关键词 reflector antenna physical optics(PO) method radiation characteristics random perforated holes
下载PDF
Deterioration Characteristics of Cement-Fly Ash Paste under Strong Ultraviolet Radiation and Low Temperature Conditions
10
作者 LIU Shuhua WANG Lu WANG Lei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第5期1092-1098,共7页
The pastes containing different dosages of fly ash were taken into ultraviolet radiation and low temperature freeze condition simultaneously(URL)for 30 days and only ultraviolet radiation condition(UR)for 30 days ... The pastes containing different dosages of fly ash were taken into ultraviolet radiation and low temperature freeze condition simultaneously(URL)for 30 days and only ultraviolet radiation condition(UR)for 30 days after standard curing,so as to investigate the influences of the conditions on the deterioration characteristics of the pastes.Microscopic test methods,such as XRD,TG-DTA and SEM,were used to study the UR effect on the deterioration process of hardened paste.The results show that the deterioration tests,such as URL and UR,inhibit the common development of paste strength,especially after the standard curing age of 360days.With the increase of fly ash dosage,from 0 to 50%,the reference value decreases,especially at early age.While at the later age,i e,180 and 360 days,the paste strength cured for 30 days under URL and UR conditions all increase to different extent and the strength is slightly affected very low,especially for the paste containing25%fly ash.From XRD results,URL and UR dispositions do not influence the hydration product kinds but the amount,especially Ca(OH)2 and CaCO3.Deterioration experiments can decrease the diffraction peak of Ca(OH)2 sharply,and increase that of CaCO3 rapidly,especially under only ultraviolet radiation.From TG-DTA and SEM results,with the increase of curing age,the content of Ca(OH)2 decreases and that of CaCO3 increases.The Ca(OH)2 content of paste under continuous UR curing for 30 days is less than that under URL curing for 30days,which indicates that UR has more negative effects on the pastes than URL. 展开更多
关键词 paste fly ash deterioration characteristics ultraviolet radiation low temperature
下载PDF
Radiation Characteristics of Rectangular Patch Antennas with an Array of Pins
11
作者 Myung-ki CHO Tae-young KIM Boo-gyoun KIM 《Journal of Measurement Science and Instrumentation》 CAS 2010年第2期142-144,共3页
The patch antennas with an array of pins (pin array patch antennas) with excellent radiation characteristics are investigated for various substrate thicknesses. The radiation in the horizontal plane of a pin array p... The patch antennas with an array of pins (pin array patch antennas) with excellent radiation characteristics are investigated for various substrate thicknesses. The radiation in the horizontal plane of a pin array patch antenna is very small compared to that of a conventional patch antenna. And the increase of forward radiation and the decrease of backward radiation of a pin array patch antenna are obtained than those conventional one's. Also the half-power beamwidth of E -plane radiation pattern of a pin array patch antenna is narrower compared to that of the conventional so that the directivity is improved. 展开更多
关键词 microstrip patch antennas pin arrays radiation characteristics substrate thickness
下载PDF
Analysis of time phase of characteristic radiation in plasma induced by laser ablating aluminum
12
作者 SONG Yi-zhong +1 位作者 ZHU Rui-fu 《原子与分子物理学报》 CAS CSCD 北大核心 2001年第4期367-371,共5页
With time and space resolved technique, we have recorded time resolved spectra of irradiation of the plasma induced by Nd: YAG laser ablating metal Aluminum in Ar, in which, laser pulse energy was set up to 145 mJ/pul... With time and space resolved technique, we have recorded time resolved spectra of irradiation of the plasma induced by Nd: YAG laser ablating metal Aluminum in Ar, in which, laser pulse energy was set up to 145 mJ/pulse and the buffer pressure 100 kpa. The continuum radiation and special emission of Aluminum plasma were studied based on the records. According to time distribution of Al Ⅰ396.15 nm emission, we analyzed the time differences between characteristic and continuum radiation evolving. We tried to explain the time phases of characteristic radiation evolving with traditional theoretical model of atomic transition. As the result, we found that it was difficult to explain our experimental results with the model. In order to explain our experimental results, we need new model or to improve the traditional theoretical model of atomic transition. 展开更多
关键词 激光剥离 激光诱导 光谱 辐射特征 等离子体
下载PDF
Research on Pulse Radiation Characteristics of Leaf-like Ultra Wide Band Antenna
13
作者 张春青 王均宏 陈美娥 《Defence Technology(防务技术)》 SCIE EI CAS 2007年第2期102-105,共4页
A new kind of ultra wideband antenna,which consists of a leaf-like dipole and a dielectric block,is proposed and analyzed.The dielectric block is attached in parallel with the dipole near its feed point.Thus,the near ... A new kind of ultra wideband antenna,which consists of a leaf-like dipole and a dielectric block,is proposed and analyzed.The dielectric block is attached in parallel with the dipole near its feed point.Thus,the near field is attracted to the side where the dielectric block is located.It leads to a focusing effect of the energy in the far zone.The finite-difference time-domain(FDTD)method combined with the perfectly matched layers(PML)technique is used in the simulation of the antenna radiation characteristics.The research shows that,with proper dielectric loading and 50 Ω feeding line,the bandwidth of the antenna can be up to 6.5 GHz,from 3.5 GHz to 10 GHz with VSWR(voltage standing wave ratio)less than 2.5. 展开更多
关键词 电子工艺 超频率 偶极子天线 电介质
下载PDF
Dark output characteristic of γ-ray irradiated CMOS digital image sensors 被引量:5
14
作者 MENG Xiangti and KANG A iguo Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084, China 《Rare Metals》 SCIE EI CAS CSCD 2002年第1期79-84,共6页
The quality of dark output images from the CMOS (complementarymetal oxide semiconductor) black and white (B & W) digital imagesensors captured before and after γ-ray irradiation was studied. Thecharacteristic par... The quality of dark output images from the CMOS (complementarymetal oxide semiconductor) black and white (B & W) digital imagesensors captured before and after γ-ray irradiation was studied. Thecharacteristic parameters of the dark output images captured atdifferent radiation dose, e.g. average brightness and itsnon-uniformity of dark out- put images, were analyzed by our testsoftware. The primary explanation for the change of the parameterswith the radi- ation dose was given. 展开更多
关键词 CMOS digital image sensor gamma radiation dark output characteristic SI
下载PDF
Experimental investigation of spectral evolution in flash radiation by hypervelocity impact on aluminum plates
15
作者 Xing Chen Yonggang Lu +1 位作者 Zhiwen Li Zhonghua Cui 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第7期96-110,共15页
In this study,a series of hypervelocity impact tests were carried out based on a two-stage light gas gun,and the sequence spectrum and radiation evolution data of the impact products under different impact conditions ... In this study,a series of hypervelocity impact tests were carried out based on a two-stage light gas gun,and the sequence spectrum and radiation evolution data of the impact products under different impact conditions were obtained.The diameter of the projectile is 3-5 mm,the impact velocity is 3.13-6.58 km/s,and the chamber pressure is 0.56-990 Pa.The spectrum of ejected debris cloud in the 250-310 nm band were obtained using a transient spectral measurement system and a multi-channel radiometer measurement system.The test results reveal that the flash radiation intensity increases as a power function with the kinetic energy of the impact.Furthermore,the peak value of the line spectrum decreases as the chamber vacuum degree increases,while the radiation width gradually expands.The line spectrum in the spectral characterization curve corresponds to the ejected debris clouds splitting phase,which does not produce significant line spectrum during material fragmentation and is dominated by the continuum spectrum produced by blackbody radiation.There will appear one or three characteristic peaks in the flash radiation time curve,the first and second peaks correspond to the penetration phase and the third peak corresponds to the expansion phase of the ejected debris clouds on the time scale,the first and second peaks are more sensitive to the chamber vacuum degree,and when the pressure is higher than 99 Pa,the first and second characteristic peaks will disappear.The radiant heat attenuation of the flash under different impact conditions is significantly different,the attenuation exponent has a power function relationship with the impact velocity and the chamber vacuum degree,while the attenuation exponent has a linear relationship with the diameter of the projectile,the specific expression of the attenuation exponent is obtained by fitting.The findings from this research can serve as a valuable reference for remote diagnostic technologies based on flash radiation characteristics. 展开更多
关键词 Hypervelocity impact Flash radiation EVOLUTION Spectral characteristics Damage evaluation
下载PDF
Experimental Research on the Double-peak Characteristic of Underwater Radiated Noise in the Near Field on Top of a Submarine 被引量:1
16
作者 刘宁 王三德 +2 位作者 郭涛 李希友 于子洋 《Journal of Marine Science and Application》 2011年第2期233-239,共7页
The double-peak characteristic of underwater radiated noise in the near field on top of the target submarine was analyzed in depth on the basis of submarine test data on the sea. The contribution of three major noise ... The double-peak characteristic of underwater radiated noise in the near field on top of the target submarine was analyzed in depth on the basis of submarine test data on the sea. The contribution of three major noise sources to the radiated noise of a submarine were compared and analyzed, and emphasis was put on the original source, production mechanism, and their correlative characteristics. On the basis of analysis on underwater tracking and pass through characteristics of the target submarine, the double-peak phenomenon was reasonably interpreted. Furthermore, the correctness of the theoretical interpretation was verified adequately in real submarine tests. The double-peak phenomenon indicates that the space distributing character on submarine radiated noise are both asymmetrical with time and space, whereas that is provided with directivity. Studying the double-peak phenomenon in depth has important reference value and meaning in engineering practice for understanding the underwater radiated noise field of submarines. 展开更多
关键词 SUBMARINE near field underwater radiated noise hydrodynamic noise double-peak characteristic
下载PDF
Simulation analysis on characteristics of land surface over western Qinghai-Xizang Plateau during freez-ing-thawing period 被引量:3
17
作者 ChengHai Wang,Rui Shi,Yang Cui,HongChao Zuo College of Atmospheric Sciences,Lanzhou University.No.222,South Tianshui Road,Lanzhou,Gansu 730000,China. 《Research in Cold and Arid Regions》 2009年第4期329-340,共12页
Using the Global Energy and Water Cycle Experiment-Asian Monsoon-Tibet Plateau Experiment (GAME-Tibet) observa-tional data-from October 2002 through September 2003-of Gaize in the western Qinghai-Xizang Plateau (QXP),... Using the Global Energy and Water Cycle Experiment-Asian Monsoon-Tibet Plateau Experiment (GAME-Tibet) observa-tional data-from October 2002 through September 2003-of Gaize in the western Qinghai-Xizang Plateau (QXP),the land-surface characteristics of the Qinghai-Xizang Plateau are simulated by the improved land-surface model Common Land Model (CoLM).The results show that CoLM can reproduce the land-surface characteristics of plateau areas well.In the sur-face-energy balance of the western QXP in the winter half year,the sensible heat (SH) flux constituted the dominant energy,and the latent heat (LH,here and after) flux is very small.Although the LH flux nearly equals zero in freezing season,it cannot be ig-nored during the period of freezing-thawing in QXP.In the transition season from midto late-May,the frequent phase change of soil water that is caused by the freezing-thawing process leads to the increase of LH flux and decrease of the Bowen ratio.The simulation results also indicate that the changes of surface effective heat fluxes (SH and LH flux) are associated with precipitation and the frequent change between freezing and thawing processes in soil surface. 展开更多
关键词 land surface characteristic Qinghai-Xizang Plateau CoLM soil freeze-thaw effective radiation
下载PDF
Effects of electron radiation on commercial power MOSFET with buck converter application 被引量:1
18
作者 Sheik Fareed Ookar Abubakkar Nor Farahidah Zabah +3 位作者 Yusof Abdullah Dhiyauddin Ahmad Fauzi Norasmahan Muridan Nurul Fadzlin Hasbullah 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第3期30-34,共5页
Microelectronic power converters such as buck and boost converter are required to be tolerant to radiations including electron radiation. This paper examines electron radiation effects on the Ⅰ-Ⅴ characteristics of ... Microelectronic power converters such as buck and boost converter are required to be tolerant to radiations including electron radiation. This paper examines electron radiation effects on the Ⅰ-Ⅴ characteristics of VDMOSFET and its corresponding effects in buck converter. Analysis of the electrical characteristics shows that after irradiation the threshold voltage and drain current for all VDMOSFETs degraded more than two orders of magnitude. The impact of this electrical degradation has been investigated in an application of typical buck converter circuit. The buck converter with n-channel switching transistor shows that after irradiation its output voltage increased with the drain current in the n-channel ZVN4424 A VDMOSFET, while the buck converter with p-channel switching transistor shows its output voltage decreased with the drain current in the p-channel ZVP4424 A VDMOSFET after irradiation. 展开更多
关键词 VDMOSFET I–V characteristics DRAIN current BUCK CONVERTER ELECTRON radiation
下载PDF
Observational results of electromagnetic radiation caused by explosion of small dimension rocks in field experiments
19
作者 金安忠 赵强 +4 位作者 姜枚 刘煜洲 王寅生 刘希强 张继红 《Acta Seismologica Sinica(English Edition)》 CSCD 1997年第1期52-59,共8页
In order to probe the mechanism of the phenomena of seismic electromagnetic radiation (EMR), we have completed field experiment on EMR caused by explosiom of rocks. In the experiments, the data of medium lo... In order to probe the mechanism of the phenomena of seismic electromagnetic radiation (EMR), we have completed field experiment on EMR caused by explosiom of rocks. In the experiments, the data of medium low freguency (<5000 Hz) EMR caused by 26 explosion tests of small dimension rocks have been obtained. This paper shows some representative observational results of the field experiment. The observational results show that, nearly 20 points of the 26 explosive points, the EMR phenomena are recorded at various degrees in the related explosive processes. The EMR intensities decay with the distance from explosive origins and increase with the explosive energy. The EMR records have certain repeatability (under the same condition), complexity( multiple EMR effects caused by one explosion) and regional characteristics such as rock structure and observational direction etc. 展开更多
关键词 explosion of rock ELECTROMAGNETIC radiation field experiment regional characteristics
下载PDF
A way of estimating the characteristic slip displacement
20
作者 Jeen-Hwa Wang 《Earthquake Science》 CSCD 2016年第1期35-43,共9页
During the ruptures of an earthquake, the strain energy, AE, will be transferred into, at least, three parts, i.e., the seismic radiation energy (Es), fracture energy (Eg), and frictional energy (Ef), that is, A... During the ruptures of an earthquake, the strain energy, AE, will be transferred into, at least, three parts, i.e., the seismic radiation energy (Es), fracture energy (Eg), and frictional energy (Ef), that is, AE = Es + Eg + El. Friction, which is represented by a velocity- and state-de- pendent friction law by some researchers, controls the three parts. One of the main parameters of the law is the char- acteristic slip displacement, De. It is significant and nec- essary to evaluate the reliable value of Dc from observed and inverted seismic data. Since Dc controls the radiation efficiency, ηR = Es/(Es + Eg), the value of qR is a good constraint of estimating Dc. Integrating observed data and inverted results of source parameters from recorded seis- mograms, the values of Es and Eg of an earthquake can be measured, thus leading to the value of ηR. The constraint used to estimate the reliable value of Dc will be described in this work. An example of estimates of Dc based on the observed and inverted values of source parameters of the September 20, 1999 Ms 7.6 Chi-Chi (Ji-Ji), Taiwan region, earthquake will be presented. 展开更多
关键词 characteristic slip displacement Seismicradiation energy Fracture energy radiation efficiency
下载PDF
上一页 1 2 67 下一页 到第
使用帮助 返回顶部