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Estimation of fracture density and orientation from azimuthal elastic impedance difference through singular value decomposition

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Petroleum Science 2021年第6期18卷 1675-1688页

作者： lin Li Guang-Zhi Zhang Jun-zhou Liu Lei Han jia-jia Zhang School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China Sinopec Exploration and Production Research Institute Beijing100083China

Accurate estimation of fracture density and orientation is of great significance for seismic characterization of fractured ***,we propose a novel methodology to estimate fracture density and orientation from azimuthal elastic impedance(AEI)difference using singular value decomposition(SVD).Based on Hudson's model,we first derive the AEI equation containing fracture density in HTI media,and then obtain basis functions and singular values from the normalized AEI difference utilizing *** shows that the basis function changing with azimuth is related to fracture orientation,fracture density is the linearly weighted sum of singular values,and the first singular value contributes the most to fracture ***,we develop an SVD-based fracture density and orientation inversion approach constrained by smooth prior elastic *** example shows that fracture density and orientation can be stably estimated,and the correlation coefficient between the true value and the estimated fracture density is above 0.85 even when an S/N ratio of *** data example shows that the estimated fracture orientation is consistent with the interpretation of image log data,and the estimated fracture density reliably indicates fractured gas-bearing reservoir,which could help to guide the exploration and development of fractured reservoirs.

关键词： Singular value decomposition HTI media Azimuthal elastic impedance inversion Fracture density Fracture orientation

瘤内无水乙醇注射联合高频热疗治疗原发性肝细胞癌的疗效分析

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肿瘤预防与治疗 2016年第6期29卷 315-319页

作者：刘佳周麟田清白健程印蓉崔西振戴宗耀段萍成都市第一人民医院肿瘤一科成都610041 四川大学华西医院胸部肿瘤科成都610041 成都市第一人民医院超声科成都610041

目的：回顾性分析瘤内无水酒精注射联合体外高频热疗治疗原发性肝细胞癌的疗效及毒副反应。方法：纳入经确诊的瘤灶最大径≤5cm、总数≤3个且无肝外病灶的原发性肝细胞癌患者42例。各病灶行B超引导下无水酒精注射共3-4次（1次/周）,注... 详细信息

目的：回顾性分析瘤内无水酒精注射联合体外高频热疗治疗原发性肝细胞癌的疗效及毒副反应。方法：纳入经确诊的瘤灶最大径≤5cm、总数≤3个且无肝外病灶的原发性肝细胞癌患者42例。各病灶行B超引导下无水酒精注射共3-4次（1次/周）,注射后隔日行局部高频热疗1小时,温度41℃-43℃。结果：全组中位随访时间32个月,疗后AFP下降率为95.2%、总客观缓解率为61.9%、中位无疾病进展生存期34个月、中位生存期40个月。肝内单发病灶较2-3个病灶的患者有生存优势（P〈0.05）。全组治疗后1度及2度肝功能损伤发生率为42.8%,1度及2度疼痛为38%,1度发热为31%。结论：该联合方案对治疗瘤灶最大径≤5cm、总数≤3个且无肝外病灶的原发性肝细胞癌的疗效较好且毒副反应较小。

关键词：原发性肝细胞癌无水酒精注射高频热疗

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苯并噁嗪高性能化应用研究进展

化学与粘合 2012年第4期34卷 72-76页

作者：周佳麟宿高明范和平王洛礼武汉软件工程职业学院湖北武汉430205 湖北省化学研究院湖北武汉430074

苯并噁嗪树脂具有低黏度,耐潮性优异,线性膨胀系数低和耐热性较高的优点,现广泛应用于电子电气、航空航天和汽车工业中。将苯并噁嗪树脂引入到电子封装材料中,以制备耐潮、耐热和可加工性能优异的满足新型封装要求的高性能电子封装材料... 详细信息

苯并噁嗪树脂具有低黏度,耐潮性优异,线性膨胀系数低和耐热性较高的优点,现广泛应用于电子电气、航空航天和汽车工业中。将苯并噁嗪树脂引入到电子封装材料中,以制备耐潮、耐热和可加工性能优异的满足新型封装要求的高性能电子封装材料,这些都需要对其进行结构改造。就苯并噁嗪树脂应用研究中存在的高耐热高阻燃性、增韧可加工性、低温固化工艺以及优良电性能方面的改性进行探讨,指出了通过分子设计结构、有机无机共混共聚及固化工艺改进等几种解决途径。

关键词：苯并噁嗪高耐热高阻燃增韧低介电

The revival of thermal utilization from the Sun: interfacial solar vapor generation

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National Science Review 2019年第3期6卷 562-578页

作者： lin zhou Xiuqiang Li George W.Ni Shining Zhu jia Zhu National Laboratory of Solid State Microstructures College of Engineering and Applied Sciences School of Physics Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of Education Collaborative Innovation Center of Advanced Microstructures Nanjing University Department of Mechanical Engineering Massachusetts Institute of Technology

Since solar energy is the ultimate energy resource and a significant amount of global energy utilization goes through heat, there have been persistent efforts for centuries to develop devices and systems for solar–thermal conversion. Most recently, interfacial solar vapor generation, as an emerging concept of solar–thermal conversion, has gained significant attention for its great potentials in various fields such as desalination, sterilization, catalysis, etc. With the advances of rationally designed materials and structures and photon and thermal management at the nanoscale, interfacial solar vapor generation has demonstrated both thermodynamic and kinetical advantages over conventional strategies. In this review, we aim to illustrate the definition, mechanism and figures of merit of interfacial solar vapor generation, and to summarize the development progress of relevant materials and applications, as well as to provide a prospective view of the future.

关键词： solar vapor generation solar absorber solar evaporator interfacial heating

Statistical characteristics and classification of ionospheric mid-latitude trough as revealed by the observations of DMSP-F18

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Earth and Planetary Physics 2025年第1期9卷 137-147页

作者： Yi Liu JiuHou Lei FuQing Huang Su zhou School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China School of Science Guiyang UniversityGuiyang 550005China

Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)*** data was obtained at an altitude of around 860 km in near polar orbit,throughout *** study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude *** differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron *** our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic *** was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct ***,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in *** ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E ***,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in *** addition,the troughs related to ion velocity(Vi)maximums could be observed in all *** troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both *** implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.

关键词： topside ionosphere mid-latitude trough ionospheric main trough auroral oval boundary temperature maximum

Vertical gradients of neutral winds observed by ICON and estimated by the Horizontal Wind Model during the geomagnetic storm on August 26−28,2021

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Earth and Planetary Physics 2025年第1期9卷 69-80页

作者： jiaWei Wu Chao Xiong YuYang Huang YunLiang zhou Department of Space Physics School of Electronic InformationHubei Luojia LaboratoryWuhan UniversityWuhan 430072China

The Michelson Interferometer for Global High-resolution Thermospheric Imaging(MIGHTI)onboard the Ionospheric Connection Explorer(ICON)satellite offers the opportunity to investigate the altitude profile of thermospheric *** this study,we used the red-line measurements of MIGHTI to compare with the results estimated by Horizontal Wind Model 14(HWM14).The data selected included both the geomagnetic quiet period(December 2019 to August 2022)and the geomagnetic storm on August 26-28,*** the geomagnetic quiet period,the estimations of neutral winds from HWM14 showed relatively good agreement with the observations from *** to the ICON observations,near the equator,zonal winds reverse from westward to eastward at around 06:00 local time(LT)at higher altitudes,and the stronger westward winds appear at later LTs at lower *** around 16:00 LT,eastward winds at 300 km reverse to westward,and vertical gradients of zonal winds similar to those at sunrise hours can be *** the middle latitudes,zonal winds reverse about 2-4 h *** winds vary more significantly than zonal winds with seasonal and latitudinal *** to the ICON observations,in the northern low latitudes,vertical reversals of meridional winds are found at 08:00-13:00 LT from 300 to 160 km and at around 18:00 LT from 300 to 200 km during the June *** reversals of meridional winds are found at 04:00-07:00 LT from 300 to 160 km and at 22:00-02:00 LT from 270 to 200 km during the December *** the southern low latitudes,meridional wind reversals occur at 08:00-11:00 LT from 200 to 160 km and at 21:00-02:00 LT from 300 to 200 km during the June *** the December solstice,reversals of the meridional wind appear at 20:00-01:00 LT below 200 km and at 06:00-11:00 LT from 300 to 160 *** the northern middle latitudes,the northward winds are dominant at 08:00-14:00 LT at 230 km during the June *** winds persist until

关键词： horizontal neutral winds vertical gradients Ionospheric Connection Explorer satellite Horizontal Wind Model 14 geomagnetic storm

Effects of mesoscale gravity waves on sporadic E simulated by a one-dimensional dynamic model

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Earth and Planetary Physics 2025年第1期9卷 1-9页

作者： Xu zhou ZeZhong Li XinAn Yue LiBo Liu Key Laboratory of Earth and Planetary Physics/Heilongjiang Mohe National Geophysical Observatory/Beijing National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of Sciences(CAS)Beijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China CAS Center for Excellence in Comparative Planetology/CAS Key Laboratory of Geospace Environment/Mengcheng National Geophysical Observatory University of Science and Technology of ChinaHefei 230026China

In addition to being driven by tidal winds,the sporadic E(Es)layers are modulated by gravity waves(GWs),although the effects are not yet comprehensively *** this article,we discuss the effects of mesoscale GWs on the Es layers determined by using a newly developed model,MISE-1D(one-dimensional Model of Ionospheric Sporadic E),with low numerical dissipation and high *** by the wind fields resolved by the high-resolution version of the Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension(WACCM-X),the MISE-1D simulation revealed that GWs significantly influence the evolution of the Es layer above 100 km but have a very limited effect at lower *** effects of GWs are diverse and complex,generally including the generation of fluctuating wavelike structures on the Es layer with frequencies similar to those of the *** mesoscale GWs can also cause increases in the density of Es layers,or they can disperse or diffuse the Es layers and increase their *** addition,the presence of GWs is a key factor in sustaining the Es layers in some cases.

关键词： sporadic E ion tidal layer gravity waves numerical simulation

High-dimensional large-scale mixed-type data imputation under missing at random

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Science China Mathematics 2025年

作者： Wei Liu Guizhen Li ling zhou Lan Luo School of Mathematics Sichuan University Center of Statistical Research and School of Statistics Southwestern University of Finance and Economics Department of Statistics and Actuarial Science University of Iowa

Missingness in mixed-type variables is commonly encountered in a variety of areas. The requirement of complete observations necessities data imputation when a moderate or large proportion of data is ***, inappropriate imputation would downgrade the performance of machine learning algorithms, leading to bad predictions and unreliable statistical inference. For high-dimensional large-scale mixed-type missing data, we develop a computationally efficient imputation method, missing value imputation via generalized factor models（MIG）, under missing at random. The proposed MIG method allows missing variables to be of different types,including continuous, binary, and count variables, and are scalable to both data size n and variable dimension p while existing imputation methods rely on restrictive assumptions such as the same type of missing variables,the low dimensionality of variables, and a limited sample size. We explicitly show that the imputation error of the proposed MIG method diminishes to zero with the rate Op(max{n-1/2, p-1/2}) as both n and p tend to infinity. Five real datasets demonstrate the superior empirical performance of the proposed MIG method over existing methods that the average normalized absolute imputation error is reduced by 5.3%–34.1%.

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Dative B–N bonds weaven toward two-dimensional purely organic materials for single crystals

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Science China Chemistry 2025年第01期 12-14页

作者： Wei-Lei zhou Siwei Wang Yong Chen College of Chemistry and Materials Science Inner Mongolia Key Laboratory of Chemistry for Nature Products and Synthesis for Functional Molecules Innovation Team of Optical Functional Molecular Devices Inner Mongolia Minzu University College of Chemistry Nankai University

Molecular topology is one of the important topics to study and understand the relationship between molecular structure and properties [1]. Particularly, two-dimensional (2D) materials with extremely high surface area and ultra-thin morphology have attracted considerable attention due to their unexpected properties in materials and chemistry [2,3].

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