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101篇 您的检索式:作者名="GAO YuFeng"
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1Scattering of SH waves induced by a symmetrical V-shaped canyon: a unified analytical solution显示文摘This paper reports a series solution of wave functions for two-dimensional scattering and diffraction of plane SH waves induced by a symmetrical V-shaped canyon with different shape ratios. A half-space with a symmetrical V-shaped canyon is divided into two sub-regions by using a circular-arc auxiliary boundary. The two sub-regions are represented by global and local cylindrical coordinate systems, respectively. In each coordinate system, the wave field satisfying the Helmholtz equation is represented by the separation of variables method, in terms of the series of both Bessel functions and Hankel functions with unknown complex coefficients. Then, the two wave fields are described in the local coordinate system using the Graf addition theorem. Finally, the unknown coefficients are sought by satisfying the continuity conditions of the auxiliary boundary. To consider the phase characteristics of the wave scattering, a parametric analysis is carried out in the time domain by assuming an incident signal of the Ricker type. Surface and subsurface transient responses demonstrate the characteristics and mechanisms of wave propagating and scattering.Zhang Ning Gao Yufeng Li Dayong Wu Yongxin Zhang Fei 2012Earthquake Engineering and Engineering Vibration2012,11,4:19
2Pm21 from Haynaldia villosa Encodes a CC-NBS- LRR Protein Conferring Powdery Mildew Resistance in Wheat显示文摘Liping Xing Ping Hu Jiaqian Liu Kamil Witek Shuang Zhou Jiefei Xu Weihao Zhou Li Gao Zhenpu Huang Ruiqi Zhang Xiue Wang Peidu Chen Haiyan Wang Jonathan D.G. Jones Miroslava Karafiatova Jan Vrana Jan Baros Jaroslav Dolezel Yuanchun Tian Yufeng Wu Aizhong Cao 2018Molecular Plant2018,11,6:16
3Chemical vapor deposition growth of large-scale hexagonal boron nitride with controllable orientation显示文摘有一致厚度的大域的六角形的硼氮化物(h-BN ) 的化学蒸汽免职(CVD ) 合成是很挑战性的,主要由于这材料的极其高的成核密度。此处,我们报导晶片规模的成功的生长,有大单人赛水晶的领域尺寸的高质量的 h-BN 单层电影,吗直到~ 72 ??????????????????????????慮潮档湡敮獬???????慮潮畴敢??洠獥灯牯????  ??Xiuju Song Junfeng Gao Yufeng Nie Teng Gao Jingyu Sun Donglin Ma Qiucheng Li Yubin Chen Chuanhong Jin Alicja Bachmatiuk Mark H. Rummeli Feng Ding Yanfeng Zhang Zhongfan Liu 2015Nano Research2015,8,10:12
4Effect of 2D spatial variability on slope reliability: A simplified FORM analysis显示文摘To meet the high demand for reliability based design of slopes, we present in this paper a simplified HLRF(Hasofere Linde Rackwitze Fiessler) iterative algorithm for first-order reliability method(FORM). It is simply formulated in x-space and requires neither transformation of correlated random variables nor optimization tools. The solution can be easily improved by iteratively adjusting the step length. The algorithm is particularly useful to practicing engineers for geotechnical reliability analysis where standalone(deterministic) numerical packages are used. Based on the proposed algorithm and through direct perturbation analysis of random variables, we conducted a case study of earth slope reliability with complete consideration of soil uncertainty and spatial variability.Jian Ji Chunshun Zhang Yufeng Gao Jayantha Kodikara 2018Geoscience Frontiers2018,9,6:12
5Fault diagnosis of wind turbine bearing based on stochastic subspace identification and multi-kernel support vector machine显示文摘In order to accurately identify a bearing fault on a wind turbine, a novel fault diagnosis method based on stochastic subspace identification(SSI) and multi-kernel support vector machine(MSVM) is proposed. Firstly, the collected vibration signal of the wind turbine bearing is processed by the SSI method to extract fault feature vectors. Then, the MSVM is constructed based on Gauss kernel support vector machine(SVM) and polynomial kernel SVM. Finally, fault feature vectors which indicate the condition of the wind turbine bearing are inputted to the MSVM for fault pattern recognition. The results indicate that the SSI-MSVM method is effective in fault diagnosis for a wind turbine bearing and can successfully identify fault types of bearing and achieve higher diagnostic accuracy than that of K-means clustering, fuzzy means clustering and traditional SVM.Hongshan ZHAO Yufeng GAO Huihai LIU Lang LI 2019Journal of Modern Power Systems and Clean Energy2019,7,2:12
6An analytical solution to the scattering of cylindrical SH waves by a partially filled semi-circular alluvial valley: near-source site effects显示文摘The earth's surface irregularities can substantially affect seismic waves and induce amplifi cations of ground motions. This study investigates whether and how the source characteristics affect the site amplifi cation effects. An analytical model of a line source of cylindrical waves impinging on an alluvial valley is proposed to link the source and site. The analytical solution to this problem proves one aspect of the strong effect of source on site amplifi cation, i.e., the wave curvature effect. It is found that the site amplifi cation depends on the source location, especially under conditions of a small source-to-site distance. Whether the displacement is amplifi ed or reduced and the size of the amplifi cation or reduction may be determined by the location of the source. It is suggested that traditional studies of site responses, which usually ignore the source effect, should be further improved by combining the source with site effects.Zhang Ning Gao Yufeng Yang Jie Xu Changjie 2015Earthquake Engineering and Engineering Vibration2015,14,2:9
7Exsolutions of Diopside and Magnetite in Olivine from Mantle Dunite,Luobusa Ophiolite,Tibet,China显示文摘摘要:透辉石和磁铁矿的 exsolutions 从披风纯橄榄岩在橄榄石以内作为共生交互生长和东方发生, Luobusa ophiolite,西藏。纯橄榄岩与橄榄石的一个矿物质集合是很新鲜的(>95%)+ 铬铁矿(1%-4%)+ 透辉石(<1%) 。橄榄石的二种类型在薄节被发现:(Fo=94 ) 是纹理粗糙的,与纽结乐队,起浪的扑灭和不规则的边缘的开发伸长了;并且其它(Fo=96 ) 有细密纹理、角度 poly。一些橄榄石谷物包含次要的 Ca, Cr 和 Ni。除在橄榄石的 exsolutions 以外,三微米尺寸包括也被发现。与单一的分析方法通过精力分析了散系统(版本) ,包括的平均作文:Na2O, 3.12%-3.84% ;MgO, 19.51%-23.79% ;Al2O3, 9.33%-11.31% ;SiO2, 44.89%-46.29% ;CaO, 11.46%-12.90% ;Cr2O3, 0.74%-2.29% ;FeO, 4.26%-5.27% ,它相当类似于闪石的那些。透辉石是在橄榄石之间充满的 anhedral,或同样微包括在橄榄石面向。铬铁矿出现 euhedral 在橄榄石之间散布了,有时与明显的组合地区。从核心减少到铬铁矿, Fe 内容增加和 Cr 的边界;并且艾尔和 Mg 在边界上极大地落下。总是在铬铁矿附近有不完全的磁铁矿地区。与在一样的节的榴状的铬铁矿相比, euhedral 铬铁矿有更高的 Fe3O4 和更低的 MgCr2O4 和 MgAl2O4 目的成员内容,它意味着它在更高的氧易逃逸环境下面形成了。与一个地温计评价,平衡水晶的温度是 820creasing 离子交换能力(IEC ) 。最高的质子电导率 w 癤?癤??REN Yufeng CHEN Fangyuan YANG Jingsui GAO Yuanhong 2008Acta Geologica Sinica(English Edition)2008,82,2:8
8Simulation of spatially correlated earthquake ground motions for engineering purposes显示文摘A new model to simulate spatially correlated earthquake ground motions is developed. In the model, the main factors that characterize three distinct effects of spatial variability, namely, the incoherency effect, the wave-passage effect and the site-response effect, are taken into account, and corresponding terms/parameters are incorporated into the well known model of uniform ground motions. Some of these terms/parameters can be determined by the root operation, and others can be calculated directly. The proposed model is fi rst verif ied theoretically, and examples of ground motion simulations are provided as a further illustration. It is proven that the ensemble expected value and the ensemble auto-/cross-spectral density functions of the simulated ground motions are identical to the target spectral density functions. The proposed model can also be used to simulate other correlated stochastic processes, such as wave and wind loads.Wu Yongxin Gao Yufeng Li Dayong 2011Earthquake Engineering and Engineering Vibration2011,10,2:7
9A note on near-field site amplification effects of ground motion from a radially inhomogeneous valley显示文摘To improve the understanding of the near-field soil and topographic amplification effects, an analytical solution by the authors for the scattering of plane SH waves by a radially inhomogeneous semi-cylindrical valley is extended to the case of a line source of cylindrical SH waves. Upon confirmation of its accuracy with past exact solutions for a homogeneous and an inhomogeneous semi-cylindrical valley under far-field plane SH waves, the extended solution is used to calculate the ground motion amplification factors for both the homogeneous and inhomogeneous valleys subjected to near-field waves. A comprehensive parametric study is conducted with respect to the location of the wave source, the dimensionless frequency of the incident waves, and the inhomogeneity degree of the covering soil layer. It is found that more amplifications and reductions of ground motions will occur within a certain range in and around the valley as the sources are located further. Consistent with the far-field case, it is confirmed that an increase of the degree of inhomogeneity of the covering soil layer generally amplifies the ground motions significantly.Zhang Ning Gao Yufeng Wu Yongxin Zhang Fei 2018Earthquake Engineering and Engineering Vibration2018,17,4:6
10Ability of lower teardrop edge to restore anatomical hip center height in total hip arthroplasty显示文摘Lu Yufeng Cheng Liming Guo Wanshou Yu Qingsheng Gao Fuqiang Zhang Qidong Liu Zhaohui Sun Wei Shi Zhencai 2014Chinese Medical Journal2014,,22:5
11Spatial variability effect of internal friction angle on the post-failure behavior of landslides using a random and non-Newtonian fluid based SPH method显示文摘This study proposed a random Smoothed Particle Hydrodynamics method for analyzing the post-failure behavior of landslides,which is based on the Karhunen-Loeve(K-L) expansion,the non-Newtonian fluid model,and the OpenMP parallel framework.Then,the applicability of this method was validated by comparing the generated random field with theoretical result and by simulating the post-failure process of an actual landslide.Thereafter,an illustrative landslide example was created and simulated to obtain the spatial variability effect of internal friction angle on the post-failure behavior of landslides under different coefficients of variation(COVs) and correlation lengths(CLs).As a conclusion,the reinforcement with materials of a larger friction angle can reduce the runout distance and impact the force of a landslide.As the increase of COV,the distribution range of influence zones also increases,which indicates that the deviation of influence zones becomes large.In addition,the correlation length in Monte Carlo simulations should not be too small,otherwise the variation range of influence zones will be underestimated.Weijie Zhang Jian Ji Yufeng Gao Xiaoyu Li Chunshun Zhang 2020Geoscience Frontiers2020,11,4:5
12Repeated febrile convulsions impair hippocampal neurons and cause synaptic damage in immature rats: neuroprotective effect of fructose-1,6-diphosphate显示文摘Fructose-1,6-diphosphate is a metabolic intermediate that promotes cell metabolism. We hypothesize that fructose-1,6-diphosphate can protect against neuronal damage induced by febrile convulsions. Hot-water bathing was used to establish a repetitive febrile convulsion model in rats aged 21 days, equivalent to 3–5 years in humans. Ninety minutes before each seizure induction, rats received an intraperitoneal injection of low- or high-dose fructose-1,6-diphosphate(500 or 1,000 mg/kg, respectively). Low- and high-dose fructose-1,6-diphosphate prolonged the latency and shortened the duration of seizures. Furthermore, high-dose fructose-1,6-diphosphate effectively reduced seizure severity. Transmission electron microscopy revealed that 24 hours after the last seizure, high-dose fructose-1,6-diphosphate reduced mitochondrial swelling, rough endoplasmic reticulum degranulation, Golgi dilation and synaptic cleft size, and increased synaptic active zone length, postsynaptic density thickness, and synaptic interface curvature in the hippocampal CA1 area. The present findings suggest that fructose-1,6-diphosphate is a neuroprotectant against hippocampal neuron and synapse damage induced by repeated febrile convulsion in immature rats.Jianping Zhou Fan Wang Jun Zhang Hui Gao Yufeng Yang Rongguo Fu 2014Neural Regeneration Research2014,9,9:4
13Effects of methylphenidate on resting-state brain activity in normal adults: an fMRI study显示文摘Methylphenidate (MPH) is one of the most commonly used stimulants for the treatment of attention deficit hyperactivity disorder (ADHD). Although several studies have evaluated the effects of MPH on human brain activation during specific cognitive tasks using functional magnetic resonance imaging (fMRI), few studies have focused on spontaneous brain activity. In the current study, we investigated the effect of MPH on the intra-regional synchronization of spontaneous brain activity during the resting state in 18 normal adult males. A handedness questionnaire and the Wechsler Adult Intelligence Scale were applied before medication, and a resting-state fMRI scan was obtained 1 h after medication (20 mg MPH or placebo, order counterbalanced between participants). We demonstrated that: (1) there were no significant differences in the performance of behavioral tasks between the MPH and placebo groups; (2) the left middle and superior temporal gyri had stronger MPH-related regional homogeneity (ReHo); and (3) the left lingual gyrus had weaker MPH-related ReHo. Our findings showed that the ReHo in some brain areas changes with MPH compared to placebo in normal adults, even though there are no behavioral differences. This method can be applied to patients with mental illness who may be treated with MPH, and be used to compare the difference between patients taking MPH and normal participants, to help reveal the mechanism of how MPH works.Yihong Zhu Bin Gao Jianming Hua Weibo Liu Yichao Deng Lijie Zhang Biao Jiang Yufeng Zang 2013Neuroscience Bulletin2013,29,1:4
14An ultrasound simulation method for carotid arteries with a wall structure of three membranes显示文摘Ultrasound simulation for carotid arteries is helpful to the performance assessments of vessel wall detection and signal processing methods by using ultrasound techniques.An ultrasound simulation method of carotid artery wall with a three-membrane structure is proposed in present study.According to the ultrasound speckle distributions varying with the shapes and densities of scatterer distributions,as well as the statistic results of the clinical images,the parameters of distributions,densities and intensities of scatterers for different kinds of tissues in the carotid artery phantoms are determined.Each region is acoustically characterized using FIELD II software to produce the radio frequency echo signals,from which ultrasound images are derived.The results based on 30 simulations show that the echo distributions of the intimae,mediae,adventitias and blood are consistent with the clinical ones.Moreover,compared with the results from the central frequency of 8 MHz,the mean measurements for thicknesses of the intima,media and adventitia membranes,as well as the lumen diameter from the simulation images based on 12 MHz are the same as the preset ones,and the maximum relative errors are the 4.01%,1.25%,0.04%and 0.15%,respectively.The simulation under this condition is more realistic.HU Xiao ZHANG Yufeng GAO Lian CAI Guanghui JIA Zhiguo ZHANG Kexin DENG Li 2015Chinese Journal of Acoustics2015,34,3:3
15Effects of vertical seismic acceleration on 3D slope stability显示文摘The conventional pseudo-static approach often neglects the effect of the vertical seismic acceleration on the stability of a slope, but some analyses under plane-strain(2D) conditions show a significant effect on the slope stability. The purpose of this study is to investigate the effect of the vertical acceleration on the safety of three-dimensional(3D) slopes. In the strict framework of limit analysis, a 3D kinematically admissible rotational failure mechanism is adopted here for 3D homogeneous slopes in frictional/cohesive soils. A set of stability charts is presented in a wide range of parameters for 3D slopes under combined horizontal and vertical seismic loading conditions. Accounting for the effects of the vertical seismic acceleration, the difference in safety factors for 3D slopes can exceed 10%, which will significantly overestimate the safety of the 3D slopes.Zhang Fei Gao Yufeng Wu Yongxin Zhang Ning Qiu Yue 2016Earthquake Engineering and Engineering Vibration2016,15,3:3
16Safety and efficacy of Yupingfeng granules in children with recurrent respiratory tract infection:A randomized clinical trial显示文摘Importance:Recurrent respiratory tract infection(RRTI)is common in children.Inappropriate RRTI treatment will lead to asthma and other diseases,thereby seriously affecting the growth and physical health of children.Immune function modulation can prevent and alleviate childhood RRTI.Yupingfeng(YPF),a patented traditional Chinese medicine(TCM),has immunomodulatory effects and is widely used in China to treat children with RRTI.Objective:To evaluate the safety and efficacy of YPF monotherapy in treating children with RRTI.Methods:This multicenter,randomized,double-blind,double-simulation,noninferiority clinical trial was conducted from January 2015 to August 2017,with an 8-week treatment period and 52-week follow-up after the drug withdrawal.Children aged 2–6 years with RRTI meeting the inclusion and exclusion criteria were enrolled in 13 hospitals in China and divided randomly into three groups(2:2:1 ratio)to receive YPF,pidotimod,or placebo.The primary outcome was the proportion of RRTI returning to normal standard level during the follow-up.The secondary outcomes were reduction in the number of RRTI recurrences,effect on clinical symptoms(in accord with TCM practice),effect per symptom,and safety.The trial was registered at the Chinese Clinical Trials Registry(www.chictr.org.cn)under the unique identifier ChiCTR-IPR-15006847.Results:Three hundred and fifty-one children were enrolled and randomly assigned to 3 groups;124,125,and 61 children in the YPF,pidotimod,and placebo groups,respectively,had completed the trial.During the follow-up,the proportion of RRTI returning to normal standard level was 73.13%,67.15%,and 38.81%with YPF,pidotimod,and placebo,respectively(P<0.0001).The proportion of cases who returned to normal standard level in the YPF group was 34.32%higher than that in the placebo group.The safety profile did not significantly differ among the groups.Interpretation:YPF granules were noninferior to the active control drug pidotimod oral solution for the treatment of RRTI in children,and were superior to placebo,with a high safety profile.Baoping Xu Xinmin Li Siyuan Hu Yixiao Bao Fengmei Chen Zhimin Chen Yonggang Du Enmei Liu Yufeng Liu Qinghui Mou Baoling Su Bo Wang Jianwen Xu Guiping Xu Qiaozhi Yang Liwei Gao Xiaohui Liu Lei Li Rong Ma Kunling Shen 2022Pediatric Investigation2022,6,2:3
17Axial gradient excitation accelerates volumetric imaging of two-photon microscopy显示文摘Two-photon excitation fluorescence microscopy(TPM),owing to its capacity for subcellular resolution,intrinsic optical sectioning,and superior penetration depth in turbid samples,has revolutionized biomedical research.However,its layer-by-layer scanning to form a three-dimensional image inherently limits the volumetric imaging speed and increases phototoxicity significantly.In this study,we develop a gradient excitation technique to accelerate TPM volumetric imaging.The axial positions of the fluorophores can be decoded from the intensity ratio of the paired images obtained by sequentially exciting the specimen with two axially elongated two-photon beams of complementary gradient intensities.We achieved a 0.63μm axial localization precision and demonstrate the flexibility of the gradient TPM on various sparsely labeled samples,including bead phantoms,mouse brain tissues,and live macrophages.Compared with traditional TPM,our technique improves volumetric imaging speed(by at least sixfold),decreases photobleaching(i.e.,less than 2.07±2.89%in 25 min),and minimizes photodamages.Yufeng Gao Xianyuan Xia Lina Liu Ting Wu Tingai Chen Jia Yu Zhili Xu Liang Wang Fei Yan Zhuo Du Jun Chu Yang Zhan Bo Peng Hui Li Wei Zheng 2022Photonics Research2022,10,3:3
18Study of the approximate approaches to the POD based spectral representation method显示文摘The spectral representation method (SRM) is most widely used in simulating the stochastic field.The proper orthogonal decomposition (POD) based SRM is an important form.This paper investigates the approximate approaches to the POD-based SRM in simulating two typical problems,i.e.,the seismic ground motion and wind velocity fields simulations.Then,the accuracy resulting from the power spectral density matrix-based POD method (PSRM) is compared to that of the coherency matrix-based POD method (CPSRM).It is concluded that the CPSRM maintains a much higher accuracy than the PSRM.In the CPSRM,the linear interpolation of eigenvectors and third-order polynomial interpolation of eigenvalues can be accepted to attain high accuracy;the linearly distributed interpolation nodes are effective in the ground motions simulation;however,the exponentially distributed interpolation nodes are effective in the wind velocity simulation.WU YongXin GAO YuFeng LI DaYong XU ChangJie MAHFOUZ Ali Hasson 2013Science China(Technological Sciences)2013,56,4:2
19Approximation approach to the SRM based on root decomposition in the simulation of spatially varying ground motions显示文摘The spectral representation method(SRM) is widely used to simulate spatially varying ground motions.This study focuses on the approximation approach to the SRM based on root decomposition,which can improve the efficiency of the simulation.The accuracy of the approximation approach may be affected by three factors: matrix for decomposition,distribution of frequency interpolation nodes and elements for interpolation.The influence of these factors on the accuracy of this approach is examined and the following conclusions are drawn.The SRM based on the root decomposition of the lagged coherency matrix exhibits greater accuracy than the SRM based on the root decomposition of the cross spectral matrix.The equal energy distribution of frequency interpolation nodes proposed in this study is more effective than the counter pith with an equal spacing.Elements for interpolation do not have much of an effect on the accuracy,so interpolation of the elements of the decomposed matrix is recommended because it is less complicated from a computational efficiency perspective.Wu Yongxin Gao Yufeng Li Dayong Xu Changjie Ali H Mahfouz 2013Earthquake Engineering and Engineering Vibration2013,12,3:2
20Inactive Al^(3+)-doped La(CoCrFeMnNiAl_(x))_(1/(5+x))O_(3)high-entropy perovskite oxides as high performance supercapacitor electrodes显示文摘A series of high-entropy perovskite oxides(HEPOs)La(CoCrFeMnNiAl_(x))_(1/(5+x))O_(3-δ)(x=0.4,0.5,0.6,and 0.7)have been synthesized by coprecipitation method combined with calcination process and explored as electrodes for supercapacitors.The crystal structure,microstructure,and elemental composition of HEPOs were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and energy-dispersive X-ray spectroscopy(EDS)in detail.The electrochemical properties of HEPOs as supercapacitor electrodes were elucidated.The specific capacitances of HEPOs(x=0.4,0.5,0.6,and 0.7)are 281.84,353.65,325.60,and 259.30 F/g at the current density of 1 A/g,respectively.After 2000 cycles,the specific capacitances of HEPOs(x=0.4,0.5,0.6,and 0.7)remain 85.01%,88.61%,86.37%,and 91.25%,respectively.Such outstanding electrochemical properties can be attributed to the entropy-stabilized structure caused by mixed six cations in B-site and the Al^(3+)-doping suppressing active ion aggregation during charge-discharge process.This research highlights the potential of HEPOs as electrodes for supercapacitors.Meng GUO Yufeng LIU Fengnian ZHANG Fuhao CHENG Chufei CHENG Yang MIAO Feng GAO Jun YU 2022Journal of Advanced Ceramics2022,11,5:2
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