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Embedding Perovskite in Polymer Matrix Achieved Positive Temperature Response with Inversed Temperature Crystallization
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作者 Meiting Peng Xue Guan +10 位作者 Yingzhu Wu Nan Zhang Qi Feng Liyong Tian Yancheng Wu Yangfan Zhang Feng Gan Fuqin Deng Meilin Huang Guichuan Xing Ningbo Yi 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第5期357-367,共11页
Organic perovskites are promising semiconductor materials for advanced photoelectric applications.Their fluorescence typically shows a negative temperature coefficient due to bandgap change and structural instability.... Organic perovskites are promising semiconductor materials for advanced photoelectric applications.Their fluorescence typically shows a negative temperature coefficient due to bandgap change and structural instability.In this study,a novel perovskite-based composite with positive sensitivity to temperature was designed and obtained based on its inverse temperature crystallization,demonstrating good flexibility and solution processability.The supercritical drying method was used to address the limitations of annealing drying in preparing high-performance perovskite.Optimizing the precursor composition proved to be an effective approach for achieving high fluorescence and structural integrity in the perovskite material.This perovskite-based composite exhibited a positive temperature sensitivity of 28.563%℃^(-1)for intensity change and excellent temperature cycling reversibility in the range of 25-40℃in an ambient environment.This made it suitable for use as a smart window with rapid response.Furthermore,the perovskite composite was found to offer temperature-sensing photoluminescence and flexible processability due to its components of perovskite-based compounds and polyethylene oxide.The organic precursor solvent could be a promising candidate for use as ink to print or write on various substrates for optoelectronic devices responding to temperature. 展开更多
关键词 FLEXIBILITY inversed temperature crystallization PEROVSKITE positive temperature response
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An inversion decomposition method for better energy resolution of NaI(Tl)scintillation detectors based on a Gaussian response matrix 被引量:5
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作者 Jian-Feng He Yao-Zong Yang +3 位作者 Jin-Hui Qu Qi-Fan Wu Hai-Ling Xiao Cong-Cong Yu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2016年第3期58-67,共10页
NaI(T1) scintillation detectors have been widely applied for gamma-ray spectrum measurements owing to advantages such as high detection efficiency and low price.However,the mitigation of the limited energy resolution ... NaI(T1) scintillation detectors have been widely applied for gamma-ray spectrum measurements owing to advantages such as high detection efficiency and low price.However,the mitigation of the limited energy resolution of these detectors,which detracts from an accurate analysis of the instrument spectra obtained,remains a crucial need.Based on the physical properties and spectrum formation processes of NaI(T1) scintillation detectors,the detector response to gamma photons with different energies is represented by photopeaks that are approximately Gaussian in shape with unique full-width-at-half-maximum(FWHM) values.The FWHM is established as a detector parameter based on resolution calibrations and is used in the construction of a general Gaussian response matrix,which is employed for the inverse decomposition of gamma spectra obtained from the detector.The Gold and Boosted Gold iterative algorithms are employed to accelerate the decomposition of the measured spectrum.Tests of the inverse decomposition method on multiple simulated overlapping peaks and on experimentally obtained U and Th radionuclide series spectra verify the practicability of the method,particularly in the low-energy region of the spectrum,providing for the accurate qualitative and quantitative analysis of radionuclides. 展开更多
关键词 闪烁探测器 能量分辨率 响应矩阵 分解方法 NAI 高斯 放射性核素 反演
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An inversion decomposition test based on Monte Carlo response matrix on the γ-ray spectra from NaI(Tl) scintillation detector 被引量:3
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作者 Jian-Feng He Qi-Fan Wu +3 位作者 Jian-Ping Cheng Fang Fang Yao-Zong Yang Jin-Hui Qu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2016年第4期181-192,共12页
The Na I(Tl) scintillation detector has a number of unique advantages, including wide use, high light yield,and its low price. It is difficult to obtain the decomposition of instrument response spectrum because of lim... The Na I(Tl) scintillation detector has a number of unique advantages, including wide use, high light yield,and its low price. It is difficult to obtain the decomposition of instrument response spectrum because of limitations associated with the Na I(Tl) scintillation detector's energy resolution. This paper, based on the physical process of c photons released from decay nuclides, generating an instrument response spectrum, uses the Monte Carlo method to simulate c photons with Na I(Tl) scintillation detector interaction. The Monte Carlo response matrix is established by different single energy γ-rays with detector effects. The Gold and the improved Boosted-Gold iterative algorithms have also been used in this paper to solve the response matrix parameters through decomposing tests,such as simulating a multi-characteristic energy c-ray spectrum and simulating synthesized overlapping peaks cray spectrum. An inversion decomposition of the c instrument response spectrum for measured samples(U series, Th series and U–Th mixed sources, among others)can be achieved under the response matrix. The decomposing spectrum can be better distinguished between the similar energy characteristic peaks, which improve the error levels of activity analysis caused by the overlapping peak with significant effects. 展开更多
关键词 闪烁探测器 矩阵分解 蒙特卡洛 NAI γ射线 反演 光谱 能量分辨率
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An inversion of site response and Lg attenuation using Lg waveform
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作者 朱新运 陈运泰 《Acta Seismologica Sinica(English Edition)》 CSCD 2007年第6期605-616,共12页
Based on spectral ratio method, a joint inversion method was used to obtain parameters of Lg wave attenuation and site response. The inversion method allows simple and direct (two-parameter) determination of Lg wave... Based on spectral ratio method, a joint inversion method was used to obtain parameters of Lg wave attenuation and site response. The inversion method allows simple and direct (two-parameter) determination of Lg wave attenuation and site response from sparse spectral data, which are not affected by radiation pattern factor and different response of same instrument after geometrical spreading. The method was used successfully for estimating site response of stations of Zhejiang Seismic Network and measuring Lg wave attenuation. The study is based on 20 earthquakes occurred in northeast of Taiwan with magnitude Ms5.0-6.7 and 960 seismic wave records from 16 stations in Zhejiang area from 2002 to 2005. The parameters of site response and Lg attenuation were calculated with a frequency interval of 0.2 Hz in the range of 0.5 Hz to 10 Hz. Lg wave attenuation coefficient corresponding to U-D, E-W and N-S components are γ(f)=0.00175f^0.43485, γ(f)=0.00145f^0.48467 and γ(f)=0.0021f^0.41241, respectively. It is found that the site response is component-independent. It is also found that the site response of QIY station is significant above the frequency of 1.5 Hz, and that the site response of NIB station is low for most frequency 展开更多
关键词 Lg wave site response parameters of attenuation joint inversion
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Gas sand distribution prediction by prestack elastic inversion based on rock physics modeling and analysis 被引量:5
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作者 贺芙邦 游俊 陈开远 《Applied Geophysics》 SCIE CSCD 2011年第3期197-205,240,共10页
Seismic inversion is one of the most widely used technologies for reservoir prediction. Many good results have been obtained but sometimes it fails to differentiate the lithologies and identify the fluids. However, se... Seismic inversion is one of the most widely used technologies for reservoir prediction. Many good results have been obtained but sometimes it fails to differentiate the lithologies and identify the fluids. However, seismic prestack elastic inversion based on rock physics modeling and analysis introduced in this paper is a significant method that can help seismic inversion and interpretation reach a new quantitative (or semi-quantitative) level from traditional qualitative interpretation. By doing rock physics modeling and forward perturbation analysis, we can quantitatively analyze the essential relationships between rock properties and seismic responses and try to find the sensitive elastic properties to the lithology, porosity, fluid type, and reservoir saturation. Finally, standard rock physics templates (RPT) can be built for specific reservoirs to guide seismic inversion interpretation results for reservoir characterization and fluids identification purpose. The gas sand distribution results of the case study in this paper proves that this method has unparalleled advantages over traditional post-stack methods, by which we can perform reservoir characterization and seismic data interpretation more quantitatively and efficiently. 展开更多
关键词 Rock physics seismic response elastic parameters elastic inversion reservoir characterization MODELING
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Fast inversion of rupture process of the 14 April 2010 Yushu,Qinghai,earthquake 被引量:2
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作者 Yong Zhang Lisheng Xu Yun-tai Chen 《Earthquake Science》 CSCD 2010年第3期201-204,共4页
Four results of the rupture process of 14 April 2010 Yushu, Qinghai, earthquake, obtained by inverting the broadband seismic data of Global Seismographic Network (GSN) based on the inversion method of earthquake rup... Four results of the rupture process of 14 April 2010 Yushu, Qinghai, earthquake, obtained by inverting the broadband seismic data of Global Seismographic Network (GSN) based on the inversion method of earthquake rupture process, were compared and discussed. It is found that the Yushu earthquake has several basic characteristics as follows: 1 There exist two principal sub-events which correspond to two slip-concentrated patches being located near the hypocenter and to the southeast of the epicenter. The rupture of the slip-concentrated patch to the southeast of the epicenter broke though the ground surface; 2 The peak slip and peak slip-rate are about 2.1 m and 1.1 m/s, respectively, indicating that the Yushu earthquake is an event with large slip-rate on the fault plane; 3 Overall the Yushu earthquake is a unilateral rupture event with the rupture mainly propagating southeastward. The strong focusing of the seismic energy in the southeast of the epicenter due to the "seismic Doppler effect" reasonably accounts for the tremendous damage in the Yushu city. 展开更多
关键词 earthquake rupture process fast inversion 2010 Yushu Qinghai earthquake earthquake emergency response
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PAM-PAA microgel inverse opal photonic crystal and pH response 被引量:1
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作者 Yong Qiang He Xiao Dong Wang +3 位作者 Jian Ying Wang Yan Feng Yong Qiang Zhao Xiu Dong You 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第11期1395-1398,共4页
The colloidal crystal template or opal with a closed-packed face-centered cubic (fcc) lattice was prepared from monodisperse polystyrene (PS) spheres by vertical sedimentation. The template provided void space for... The colloidal crystal template or opal with a closed-packed face-centered cubic (fcc) lattice was prepared from monodisperse polystyrene (PS) spheres by vertical sedimentation. The template provided void space for infiltration of monomer precursor composed of acrylate acid, acrylamide and ammonium-persulfate, as well as microgel from the subsequent copolymerization. The sample was immersed in dimethylbenzene for completely removing PS spheres to form PAM inverse opal hydrogels (IOHPAM) or PAM/PAA inverse opal hydrogels (IOHPAM/PAA) photonic crystals. The PS spheres were replaced by air spheres, which interconnected each other through the windows. The study of responses to pH show that there are two peaks for both IOHPAM and IOHPAM/PAA films, but the IOHPAM/PAA peaks shift to higher pH, and the peaks are independent with the AA content. 展开更多
关键词 Photonic crystal pH response PAM/PAA OPAL inverse opal hydrogel
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ROBUST SMITH PREDICTIVE CONTROLLER FOR PROCESS WITH INVERSE RESPONSE
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作者 钟庆昌 谢剑英 《Journal of Shanghai Jiaotong university(Science)》 EI 1999年第2期10-16,共7页
Smith predictor known as the time delay compensator was extended to control the process with inverse response.Modern robust control theory was employed to design the robust controller,which has only one parameter to b... Smith predictor known as the time delay compensator was extended to control the process with inverse response.Modern robust control theory was employed to design the robust controller,which has only one parameter to be determined with compromise among the rise time,undershoot,robustness and capability to reject disturbance of the closed loop system.The former two specifications can be assessed quantitatively and the latter two qualitatively.Examples show that the proposed method has significant improvements and wide applicable ranges for inverse response process. 展开更多
关键词 Smith predictor inversE responsE PROCESS (IRP) non minimum phase (NMP) sensitivity function PROCESS control inversE responsE COMPENSATOR open right half zero
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Inversion of waveforms from Xiangtang borehole seismic array for soil dynamic property
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作者 陈学良 金星 +1 位作者 陶夏新 韦永祥 《Acta Seismologica Sinica(English Edition)》 CSCD 2007年第4期425-434,共10页
In order to understand the site soil response of the Xiangtang borehole seismic array under real strong ground motion, reveal the site response, verify the technique of borehole exploration, and improve the precision ... In order to understand the site soil response of the Xiangtang borehole seismic array under real strong ground motion, reveal the site response, verify the technique of borehole exploration, and improve the precision of in-situ test and laboratory test, this paper presents a new approach, which is composed of two methods. One is the layered site seismic response method, whose layer transform matrix is always real. The other is a global-local optimization technique, which uses genetic algorithm (GA)-simplex method. An inversion of multi-component waveforms of P, SV and SH wave is carried out simultaneously. By inverting the records of three moderate and small earthquakes obtained from the Xiangtang borehole array (2^#) site, the soil dynamic characteristic parameters, including P velocity, damping ratio and frequency-dependent coefficient b, which has not been given in previous literatures, are calculated. The results show that the soil S wave velocity of the Xiangtang 2^# borehole is generally greater than that obtained from the 1994 in-situ test, and is close to the velocity of the 3^# borehole, which is more than 200 m away from the 2^# borehole. Meanwhile, perceptible soil nonlinear behavior under peak ground motion of about 60×10^-2 m/s^2 is detected by the inversion analysis. The presented method can be used for studying the soil response of other borehole array sites. 展开更多
关键词 Xiangtang borehole array inversion analysis soil response P and S wave velocity damping ratio
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Adaptive inverse control of random vibration based on the filtered-X LMS algorithm 被引量:10
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作者 Yang Zhidong,Huang Qitao~(++),Han Junwei~§and Li Hongren~§National Key Laboratory of Robots Technique and System,Harbin Institute of Technology,Harbin 150080,China PhD Candidate ~++ PhD ~§Professor 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第1期141-146,共6页
Random vibration control is aimed at reproducing the power spectral density (PSD) at specified control points. The classical frequency-spectrum equalization algorithm needs to compute the average of the multiple fre... Random vibration control is aimed at reproducing the power spectral density (PSD) at specified control points. The classical frequency-spectrum equalization algorithm needs to compute the average of the multiple frequency response functions (FRFs), which lengthens the control loop time in the equalization process. Likewise, the feedback control algorithm has a very slow convergence rate due to the small value of the feedback gain parameter to ensure stability of the system. To overcome these limitations, an adaptive inverse control of random vibrations based on the filtered-X least mean-square (LMS) algorithm is proposed. Furthermore, according to the description and iteration characteristics of random vibration tests in the frequency domain, the frequency domain LMS algorithm is adopted to refine the inverse characteristics of the FRF instead of the traditional time domain LMS algorithm. This inverse characteristic, which is called the impedance function of the system under control, is used to update the drive PSD directly. The test results indicated that in addition to successfully avoiding the instability problem that occurs during the iteration process, the adaptive control strategy minimizes the amount of time needed to obtain a short control loop and achieve equalization. 展开更多
关键词 random vibration power spectral density frequency response function adaptive inverse control filtered-X LMS algorithm
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Signal modeling and impulse response shaping for semiconductor detectors 被引量:5
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作者 Xue-Yuan Wang Jian-Bin Zhou +4 位作者 Ming Wang Huai-Ping Wang Xu Hong Yi Liu Ping Huang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2022年第4期72-82,共11页
The output-signal models and impulse response shaping(IRS)functions of semiconductor detectors are important for establishing high-precision measurement systems.In this paper,an output-signal model for semiconductor d... The output-signal models and impulse response shaping(IRS)functions of semiconductor detectors are important for establishing high-precision measurement systems.In this paper,an output-signal model for semiconductor detector systems is proposed.According to the proposed model,a multistage cascade deconvolution IRS algorithm was developed using the C-R inverse system,R-C inverse system,and differentiator system.The silicon drift detector signals acquired from the analog-to-digital converter were tested.The experimental results indicated that the shaped pulses obtained using the proposed model had no undershoot,and the average peak base width of the output shaped pulses was reduced by 36%compared with that for a simple model proposed in a previous work[1].Offline processing results indicated that compared with the traditional IRS algorithm,the average peak base width of the output shaped pulses obtained using the proposed algorithm was reduced by 11%,and the total elapsed time required for pulse shaping was reduced by 26%.The proposed algorithm avoids recursive calculation.If the sampling frequency of the digital system reaches 100 MHz,the proposed algorithm can be simplified to integer arithmetic.The proposed IRS algorithm can be applied to high-resolution energy spectrum analysis,highcounting rate energy spectrum correction,and coincidence and anti-coincidence measurements. 展开更多
关键词 Output-signal model Impulse response shaping C-R inverse system R-C inverse system Integer arithmetic
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Carbon dioxide/calcium oxide responsive behavior and application potential of amine emulsion 被引量:1
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作者 REN Yanjun LU Yanyan +4 位作者 JIANG Guancheng ZHOU Wenjing WU Liansong YAO Rugang XIE Shuixiang 《Petroleum Exploration and Development》 CSCD 2021年第5期1173-1182,共10页
Green and low cost CO_(2) and CaO were used to stimulate amine emulsions to reveal the responsive behavior of amine emulsions.On this basis,oil-based drilling fluids responsive to CO_(2) and CaO were formulated and th... Green and low cost CO_(2) and CaO were used to stimulate amine emulsions to reveal the responsive behavior of amine emulsions.On this basis,oil-based drilling fluids responsive to CO_(2) and CaO were formulated and their properties were evaluated.The results showed that the amine emulsions inversed from water-in-oil state to oil-in-water state readily and their rheological behavior underwent transitions of decreasing,rising again and decreasing again via induction by CO_(2).These CO_(2) responsive behaviors could be reversed by CaO.Oil-based drilling fluids prepared based on the amine emulsions with oil-water volume ratios of 50:50 to 70:30,densities of 1.4-2.0 g/cm^(3) had good rheological and filtration properties at 160℃;and be readily cleaned up using CO_(2) bubbling.The useless solid phase with low density could be removed efficiently via reducing the viscosity of emulsion by CO_(2) and the residual liquid phase could be restored to the original state by CaO and reused to prepare drilling fluid.The mechanisms analysis indicated that CO_(2)/CaO induced the reversible conversion between amine emulsifiers and their salts,which enabled the reversible regulation of both the hydrophilic-lipophilic balance of amine emulsifiers and the emulsion particles’size and finally caused the controllable-reversion of the form and rheology of amine emulsion. 展开更多
关键词 oil-based drilling fluid amine emulsion CO_(2)/CaO response emulsion inversion controlled reversible property recycling
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Performance Analysis of an Inverse Notch Filter and Its Application to <i>F<sub>0</sub></i>Estimation
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作者 Yosuke Sugiura Arata Kawamura Youji Iiguni 《Circuits and Systems》 2013年第1期117-122,共6页
In this paper, we analyze an inverse notch filter and present its application to F0 (fundamental frequency) estimation. The inverse notch filter is a narrow band pass filter and it has an infinite impulse response. We... In this paper, we analyze an inverse notch filter and present its application to F0 (fundamental frequency) estimation. The inverse notch filter is a narrow band pass filter and it has an infinite impulse response. We derive the explicit forms for the impulse response and the sum of squared impulse response. Based on the analysis result, we derive a normalized inverse notch filter whose pass band area is identical to unit. As an application of the normalized inverse notch filter, we propose an F0 estimation method for a musical sound. The F0 estimation method is achieved by connecting the normalized inverse notch filters in parallel. Estimation results show that the proposed F0 estimation method effectively detects F0s for piano sounds in a mid-range. 展开更多
关键词 Band Pass FILTER inversE Notch FILTER IMPULSE response Analysis
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基于压痕试验的岩石力学参数的卡尔曼滤波反演
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作者 王鹏 房凯 +1 位作者 赵同彬 刘丽娜 《山东科技大学学报(自然科学版)》 CAS 北大核心 2024年第4期1-11,共11页
压痕试验是间接评估岩体力学特性的重要方法,为了更好地利用压痕试验评估岩体力学参数,本研究采用一种基于扩展卡尔曼滤波算法的参数反演方法。基于室内压痕试验获得的荷载-压入深度曲线数据,通过弹塑性数值仿真模型构建岩体弹塑性参数... 压痕试验是间接评估岩体力学特性的重要方法,为了更好地利用压痕试验评估岩体力学参数,本研究采用一种基于扩展卡尔曼滤波算法的参数反演方法。基于室内压痕试验获得的荷载-压入深度曲线数据,通过弹塑性数值仿真模型构建岩体弹塑性参数与压痕曲线的响应关系,进而利用卡尔曼滤波算法实现对岩石弹塑性参数的反演和优化分析。结果表明,本研究方法具有较好的收敛性和较高的识别精度,反演得到的岩石弹性参数均值的相对误差在10%左右,塑性参数的反演结果相对误差小于20%。较传统单一经验公式方法,本研究方法具有更高的预测精度,对多种不同岩性岩体都有较好的适用性。 展开更多
关键词 岩石力学参数 压痕试验 卡尔曼滤波 反演分析 响应面
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中基性火山岩多种叠前反演算法对比、优选及应用——以查干花地区火石岭组为例
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作者 李瑞磊 曹磊 +2 位作者 樊薛沛 冯晓辉 李宁 《油气藏评价与开发》 CSCD 北大核心 2024年第2期207-215,共9页
目前应用最广泛的叠前同时反演算法是基于各项同性水平介质的Zoeppritz方程近似表达式,但对于具有岩性横向变化快且纵向多期叠置特点的中基性火山岩储层,凝灰岩和沉凝灰岩具有相近的测井和地球物理响应,叠前同时反演在火山岩岩性、物性... 目前应用最广泛的叠前同时反演算法是基于各项同性水平介质的Zoeppritz方程近似表达式,但对于具有岩性横向变化快且纵向多期叠置特点的中基性火山岩储层,凝灰岩和沉凝灰岩具有相近的测井和地球物理响应,叠前同时反演在火山岩岩性、物性的区分上存在一定的局限性。通过褶积模型正演定性分析火山岩储层地震响应特征,井上岩石物理分析火山岩储层岩性、物性敏感参数,通过模型试算和实际数据计算对比分析6种Zoeppritz方程近似的二项式和三项式叠前反演算法在该地区的适用性,从而优选出SMITH&GIDLOW,FATTI近似算法,输入纵波阻抗、横波阻抗和密度的反射系数进行叠前反演,应用叠前纵波阻抗反演结果对该地区凝灰岩进行预测,应用叠前密度反演结果对有效储层物性进行预测。支撑部署1口评价井,预测符合率为76.0%,部署1口水平井,预测符合率为84.6%,均获得工业气流。 展开更多
关键词 叠前反演 火山岩 地震响应 岩石物理 物性预测
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负载花色苷的抗酸性羧甲基壳聚糖凝胶微球的缓释研究
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作者 李煦 储若晴 +3 位作者 刘欣茹 刘长霞 叶霞 范小振 《食品工业科技》 CAS 北大核心 2024年第15期152-160,共9页
为拓宽壳聚糖基水凝胶的应用范围,构筑可食用的花色苷(ACNs)递送体系,采用反相乳液法,以玉米油为连续相,水杨醛(SA)为交联剂,制备了具有抗酸性能的载ACNs羧甲基壳聚糖(CMCS)凝胶微球(ACNs/CMCS-SA),表征了其结构和形貌,研究了其稳定性... 为拓宽壳聚糖基水凝胶的应用范围,构筑可食用的花色苷(ACNs)递送体系,采用反相乳液法,以玉米油为连续相,水杨醛(SA)为交联剂,制备了具有抗酸性能的载ACNs羧甲基壳聚糖(CMCS)凝胶微球(ACNs/CMCS-SA),表征了其结构和形貌,研究了其稳定性、溶胀性能和缓释性能。结果表明,ACNs/CMCSSA具有微米级粒径,表面光滑呈圆形;ACNs/CMCS-SA在酸性条件下稳定性良好,溶胀和缓释过程展现pH响应性;ACNs的释放行为符合Weibull模型,pH7和9时为扩散和骨架溶蚀复合释放机制控制,pH3和5时为菲克扩散和Case Ⅱ transport(0级-溶胀依赖性释放)联合释放机制控制。ACNs/CMCS-SA制备方法简单,过程绿色;对ACNs展现良好的胃酸保护和肠道释放性能,为环境友好型药物包封材料的开发和ACNs的应用提供了理论和实践参考。 展开更多
关键词 花色苷(ACNs) 释放性能 动力学 PH 响应 反相乳液法 凝胶微球
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行人腿型冲击器肌肉材料参数反求
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作者 崔世海 杨宇 +3 位作者 闫晓晓 李海岩 贺丽娟 吕文乐 《汽车工程学报》 2024年第3期463-469,共7页
aPLI先进行人腿型冲击器在碰撞测试中的生物仿真度,在很大程度上取决于其几何结构及其模拟腿部肌肉的合成橡胶的超弹性力学特性。根据橡胶准静态单轴压缩试验数据,分别对用于表述橡胶超弹性的Ogden和Mooney-Rivlin本构模型进行材料参数... aPLI先进行人腿型冲击器在碰撞测试中的生物仿真度,在很大程度上取决于其几何结构及其模拟腿部肌肉的合成橡胶的超弹性力学特性。根据橡胶准静态单轴压缩试验数据,分别对用于表述橡胶超弹性的Ogden和Mooney-Rivlin本构模型进行材料参数拟合,得到相应的材料参数并将拟合曲线与试验曲线进行比较,对比不同本构模型的拟合精度。结果表明,2阶Ogden材料模型更符合试验结果。为提高有限元模型中肌肉橡胶材料参数的准确性,重构压缩试验有限元模型,以拟合得到的2阶Ogden本构模型材料参数为初始值,通过将有限元与优化策略相结合,基于自适应响应面法对2阶Ogden模型中μ1、α1、μ2、α2这4个材料参数进行优化,获得该材料在准静态压缩状态下的一组最佳材料参数。 展开更多
关键词 行人保护 行人腿型冲击器肌肉 本构模型 自适应响应面法 参数反求
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天津典型观测井渗透性变化及对玛多7.4级地震响应机理分析
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作者 李悦 马晗宇 +2 位作者 刘振辉 王熠熙 邵永新 《地震》 CSCD 北大核心 2024年第2期33-51,共19页
采用微水试验和固体潮汐反演两种方法计算了王3井、宝坻新井、宁河井不同时期渗透系数,经对比分析发现,两种方法计算含水层渗透系数所得结果在总体量级上是相当的,并且变化趋势是一致的,发育稳定、连续性较好的含水层中的观测井,二者计... 采用微水试验和固体潮汐反演两种方法计算了王3井、宝坻新井、宁河井不同时期渗透系数,经对比分析发现,两种方法计算含水层渗透系数所得结果在总体量级上是相当的,并且变化趋势是一致的,发育稳定、连续性较好的含水层中的观测井,二者计算结果更加接近。微水试验估算的井含水层渗透系数主要反映了井孔周围局部含水层渗透能力在短时间内水流过程中的渗透性特征,而固体潮汐反演估算的渗透系数则反映了在较长时间内较大范围含水层的平均渗透能力。因而,在观测井同震响应分析、抽(注)水干扰等异常核实分析中,使用微水试验估算的井含水层渗透系数更为合理,而在分析区域应力场变化中使用固体潮汐反演估算的渗透系数则更合理。本文分析了三口观测井水位和渗透性变化特征以及产生原因,并进一步分析了王3井和宝坻新井水位对2021年5月22日青海玛多7.4级地震同震响应机理,以及玛多地震对宁河井水位观测的影响机制,发现应力积累、抽/注水干扰、地震波传播等因素均会对含水介质渗透性造成影响。并且,地震波传播过程对不同含水介质造成的影响不同,而含水层岩性相同的不同观测井对同一地震的响应特征和机理也不相同。 展开更多
关键词 渗透系数 微水试验 固体潮汐反演 同震响应 2021年玛多7.4级地震
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双线大直径输水隧道建设对既有桥梁及桩基的影响分析
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作者 杨杰 张帅超 +2 位作者 马春辉 秦全乐 周永林 《水资源与水工程学报》 CSCD 北大核心 2024年第3期154-163,172,共11页
为准确分析双线大直径输水隧道下穿对既有桥梁结构的影响,构建桥梁-地层-桩基-盾构隧道高精度数值仿真模型,对桥梁桩基结构及盾构过程进行精细化模拟,结合基于智能算法的土层参数反演模型,获取更接近真实情况的土层参数,以提高数值模拟... 为准确分析双线大直径输水隧道下穿对既有桥梁结构的影响,构建桥梁-地层-桩基-盾构隧道高精度数值仿真模型,对桥梁桩基结构及盾构过程进行精细化模拟,结合基于智能算法的土层参数反演模型,获取更接近真实情况的土层参数,以提高数值模拟精度。结果表明:输水隧道盾构开挖引起的地表最大沉降量为15.01 mm,基于反演的地表变形计算结果与实际监测值的误差减少约70%;盾构隧道双线开挖会引起地表二次沉降变形,两条盾构隧道中间区域的地表二次沉降量最大,约占总沉降量的60%,最大二次沉降量为5.06 mm;隧道两侧的桩基受到影响较大,最大位移为10.03 mm,位于桩基顶部,而隧道开挖对桩基内应力分布影响较小,可以认为无影响。 展开更多
关键词 输水隧道 桥梁 桩基响应 反演模型 大直径盾构 变形监测
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基于波谱响应特征的雄安新区农田土壤重金属含量反演
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作者 李旭青 顾会涛 +5 位作者 丁雪瑶 张文龙 李凌飞 唐瑞尹 陈旭颖 吴艳萍 《农业工程学报》 EI CAS CSCD 北大核心 2024年第4期121-128,共8页
分析并监测雄安新区农田土壤污染状况,对于保障粮食安全、建设绿色雄安具有重要意义。该研究以雄安新区为研究区,基于多源遥感数据珠海一号(Zhuhai-1)OHS数据、哨兵二号(Sentinel-2)L2A级数据的波谱响应特征及实地测得的农田土壤重金属... 分析并监测雄安新区农田土壤污染状况,对于保障粮食安全、建设绿色雄安具有重要意义。该研究以雄安新区为研究区,基于多源遥感数据珠海一号(Zhuhai-1)OHS数据、哨兵二号(Sentinel-2)L2A级数据的波谱响应特征及实地测得的农田土壤重金属含量数据,在对土壤重金属含量单因子与多因子污染评价的基础上,筛选出3种超标的农田重金属元素铅(Pb)、铜(Cu)、锌(Zn),采用偏最小二乘回归方法(partial least squares regression,PLSR)建立农田土壤重金属含量反演模型。利用Zhuhai-1提取土壤样本点的原始光谱反射率以及4种变换后的光谱反射率,Sentinel-2提取7种对重金属胁迫敏感的植被指数,将其与3种土壤重金属含量作相关性分析,筛选出敏感波段与植被指数,即波谱响应特征,构建土壤重金属含量反演模型。结果表明,3种模型整体反演精度较为优良,Pb含量反演模型决定系数(determination coefficient,R^(2))为0.490,均方根误差(root mean squared error,RMSE)为4.66 mg/kg,平均绝对值误差(mean absolute error,MAE)为1.92 mg/kg;Cu含量反演模型R^(2)为0.491,RMSE为16.85 mg/kg,MAE为3.69 mg/kg;Zn含量反演模型R^(2)为0.664,RMSE为20.63 mg/kg,MAE为9.36 mg/kg。将该模型应用于雄安新区农田区域,得到大部分农田土壤中Pb含量均未超过风险筛选标准,在研究区西南部、西部部分区域Cu含量超过土壤污染风险筛选值,同时在研究区西部、西南部Zn污染较严重,雄安新区东南部部分农田有Zn零星分布,其他区域Cu和Zn含量未超过国家土壤污染风险管控值。因此,利用多源遥感数据波谱响应特征反演土壤重金属Pb、Cu和Zn含量,能够快速准确地实现对雄安新区土壤重金属污染情况的调查,同时为大面积土壤重金属含量监测提供解决方案。 展开更多
关键词 土壤 重金属 反演 多源遥感 波谱响应 农田
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