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A review of rock macro-indentation:Theories,experiments,simulations,and applications

Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2351-2374页

作者： weiqiang xie Xiaoli Liu Xiaoping Zhang Xinmei Yang Xiaoxiong Zhou State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing100084China Yunlong Lake Laboratory of Deep Underground Science and Engineering Xuzhou221116China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China

Rock macro-indentation plays a fundamental role in mechanical rock breaking for various rock engineering application,such as drilling,tunneling,cutting,and *** the past decades,extensive research has been conducted to understand the indentation mechanisms and responses through various *** review aims to provide an overview of the current status and recent advancements in theories,experiments,numerical simulations,and applications of macro-indentation in rock *** starts with elaborating on the mechanisms of macro-indentation,followed by a discussion of the merits and limitations of commonly used *** factors and their effects on indentation test results are then *** numerical simulation methods for rock macro-indentation are highlighted,along with their advantages and ***,the applications of indentation tests and indentation indices in characterizing rock properties are *** reveals that compression-tension,compression-shear,and composite models are widely employed in rock *** the compression-tension model is straightforward to use,it may overlook the anisotropic properties of *** the other hand,the composite model provides a more comprehensive description of rock indentation but requires complex ***,factors,such as indentation rate,indenter geometry,rock type,specimen size,and confining pressure,can significantly influence the indentation *** methods for macro-indentation encompass continuous medium,discontinuous medium,and continuous-discontinuous medium methods,with selection based on their differences in ***,rock macro-indentation can be practically applied to mining engineering,tunneling engineering,and petroleum drilling *** indices serve as valuable tools for characterizing rock strength,brittleness,and *** review sheds light on the development of rock macro-inde

关键词： Rock macro-indentation Indentation test Indentation indices Mechanism Rock breaking

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基于多角度投影方法的砂土颗粒三维形态表征

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清华大学学报（自然科学版） 2024年第2期64卷 294-302页

作者：谢维强张晓平刘晓丽周小雄刘泉声清华大学水沙科学与水利水电工程国家重点实验室北京100084 深地科学与工程云龙湖实验室徐州221116 武汉大学岩土与结构工程安全湖北省重点实验室武汉430072

砂土颗粒的形态学特征(尺寸和形状)对于评估砂土材料的力学特性至关重要,因此准确地量化其三维形态学特征是研究砂土材料力学特性的前提工作。相比三维测试(表征)方法,二维测试(表征)方法具有测试方式多、程序简单、成本低等优点。为研... 详细信息

砂土颗粒的形态学特征(尺寸和形状)对于评估砂土材料的力学特性至关重要,因此准确地量化其三维形态学特征是研究砂土材料力学特性的前提工作。相比三维测试(表征)方法,二维测试(表征)方法具有测试方式多、程序简单、成本低等优点。为研究二维图像对砂土颗粒三维形态的表征,利用三维激光扫描技术获取砂土颗粒的三维点云数据;然后利用计算机算法重构砂粒的三维模型,准确快速地自动提取砂粒的三维形态特征;借助算法获取了随机单一投影法、最大最小投影面积法(选自1000张投影)和三正交方向投影法下的砂粒二维形态参数;分析了二维参数与三维参数之间的相关关系,提出了基于砂土颗粒二维形态特征表征三维形态特征的可靠方法。结果表明,砂土颗粒的三维尺寸(长、宽、厚)可使用相应的二维尺寸估算(线性拟合系数R~2=0.735~0.994);3种投影方法中,最大最小投影面积法和三正交方向投影法可准确地估算砂土颗粒的三维形态,为砂土材料的快速定量化表征提供了实用方法。

关键词：砂土颗粒形态特征三维激光扫描二维投影数字图像处理

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物理防治在林业有害生物防治中的应用研究

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中国林副特产 2024年第4期 24-25页

作者：谢伟强甘肃省小陇山人造板有限公司甘肃小陇山741400

探究物理防治措施在林业有害生物防治中应用的效果。以梨树果园作为研究对象,采用化学、频振式诱杀等进行虫害防治,分析物理防治方式在虫害防治中的效果,比较两种防治方式的经济效益。结果表明:平均单灯诱杀害虫数量为3960.71只,包括鳞... 详细信息

探究物理防治措施在林业有害生物防治中应用的效果。以梨树果园作为研究对象,采用化学、频振式诱杀等进行虫害防治,分析物理防治方式在虫害防治中的效果,比较两种防治方式的经济效益。结果表明:平均单灯诱杀害虫数量为3960.71只,包括鳞翅目、鞘翅目、直翅目、同翅目以及半翅目等5个目的18种害虫。采用物理防治方式可以有效进行林业有害生物的防治,且能够有效降低病虫害防治的成本。

关键词：物理防治化学防治有害生物梨树效果经济效益

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特高压交直流输电线路带电作业安全防护及碳减排效应分析

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电测与仪表 2024年第8期61卷 47-54页

作者：马爱清毕永翔陈鑫涛谢伟强上海电力大学电气工程学院上海200090

特高压(ultra high voltage,UHV)交流与直流线路同廊道运行时带电作业区域电压高、场强大,交直流混合电场比单一电场更为复杂。为确保作业人员安全,结合实际±1100 kV直流和1000 kV交流线路,建立了包含输电导线、杆塔及带电作业人员的... 详细信息

特高压(ultra high voltage,UHV)交流与直流线路同廊道运行时带电作业区域电压高、场强大,交直流混合电场比单一电场更为复杂。为确保作业人员安全,结合实际±1100 kV直流和1000 kV交流线路,建立了包含输电导线、杆塔及带电作业人员的三维计算模型,通过分析开展带电作业时人员的体表混合场强、电位转移电流及暂态能量,对作业人员安全防护进行研究。结果表明:随着作业人员不断接近直流线路,体表场强受交流线路影响越明显,最高可使作业人员体表场强增大约9%,达到1920 kV/m;交流线路的存在将导致电位转移电流增长约7%,但对暂态能量影响较小。通过对特高压线路不停电检修所减少的碳排放量进行进一步计算,验证了特高压带电作业对减少碳排放具有促进作用。

关键词：特高压输电线路交直流同廊道体表混合电场电位转移电流暂态能量碳减排

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一种WiFi混合滤波的RSSI室内定位算法

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导航定位学报 2024年第3期12卷 102-111页

作者：于兵柳鑫程海波谢玮强蔡希玮南京信息工程大学电子与信息工程学院南京210044 江苏省大气环境与装备技术协同创新中心南京210044

针对接收信号强度指示(RSSI)在基于WiFi的室内定位应用中易受到环境影响出现波动、突变进而导致定位精度降低的问题,提出了一种WiFi混合滤波的RSSI室内定位算法。首先,根据WiFi信号距离衰减模型设计一种自适应阈值滤波器剔除观测信号异... 详细信息

针对接收信号强度指示(RSSI)在基于WiFi的室内定位应用中易受到环境影响出现波动、突变进而导致定位精度降低的问题,提出了一种WiFi混合滤波的RSSI室内定位算法。首先,根据WiFi信号距离衰减模型设计一种自适应阈值滤波器剔除观测信号异常值;然后,根据自适应阈值滤波、卡尔曼(Kalman)滤波、均值(Mean)滤波设计了一种混合滤波算法(ATKM)对RSSI数据进行滤波;最后,提出了一种基于斯皮尔曼-欧几里得距离的加权K近邻算法(SEWKNN)进行位置估计。在真实环境下的实测结果表明,本文提出的ATKM滤波算法能显著降低RSSI信号的波动,提出的SEWKNN算法在室内环境中平均定位误差为1.17 m,在走廊环境中平均定位误差为1.53m,相比传统的WKNN算法平均定位误差分别下降18.18%和16.84%。

关键词：接收信号强度指示室内定位混合滤波指纹匹配斯皮尔曼相关系数

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Silicon-integrated nonlinear Ⅲ-Ⅴ photonics

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Photonics Research 2022年第2期10卷 535-541页

作者： weiqiang xie Chao Xiang Lin Chang Warren Jin Jonathan Peters John E.Bowers Department of Electrical and Computer Engineering University of CaliforniaSanta BarbaraSanta BarbaraCalifornia 93106USA Current address:Department of Electronic Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Mainstream silicon photonic integrated circuits are based on compact and low-loss silicon-on-insulator(SOI)waveguide platforms. However, monolithic SOI-based photonics provides only a limited number of functional device types. Here, to extend the on-chip capabilities, we propose a general heterogeneous integration approach to embed highly nonlinear Ⅲ-Ⅴ(Al Ga As) photonics into the SOI platform. We develop low-loss AlGaAs-on-SOI photonic circuits with integrated Si waveguides and showcase sub-milliwatt-threshold(-25 mW) Kerr frequency comb generation in ultrahigh-QAlGaAs microrings(Q over 10^(6)) at the telecom bands. Our demonstration complements existing mature Si photonics technology with efficient nonlinear functionalities provided by Ⅲ-Ⅴ and propels conventional Si photonics into emerging nonlinear photonic applications towards fully chip-based nonlinear engines.

关键词： SOI AlGaAs waveguide

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Solvent effects on Diels-Alder reaction in ionic liquids:A reaction density functional study

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Chinese Journal of Chemical Engineering 2024年第2期66卷 180-188页

作者： Zijiang Dou weiqiang Tang Peng xie Shuangliang Zhao Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology and School of Chemistry and Chemical Engineering Guangxi UniversityNanning 530004China State Key Laboratory of Chemical Engineering and School of Chemical Engineering East China University of Science and TechnologyShanghai 200237China

Extensive experimental studies have been performed on the Diels-Alder(DA)reactions in ionic liquids(ILs),which demonstrate that the IL environment can significantly influence the reaction rates and ***,the underlying microscopic mechanism remains *** this work,the multiscale reaction density functional theory is applied to explore the effect of 1-butyl-3-methylimidazolium hexafluorophosphate([BMIM][PF_(6)])solvent on the reaction of cyclopentadiene(CP)with acrolein,methyl acrylate,or *** analyzing the free energy landscape during the reaction,it is found that the polarization effect has a relatively small influence,while the solvation effect makes both the activation free energy and reaction free energy *** addition,the rearrangement of local solvent structure shows that the cation spatial distribution responds more evidently to the reaction than the anion,and this indicates that the cation plays a dominant role in the solvation effect and so as to affect the reaction rates and selectivity of the DA reactions.

关键词： Solvent effect Ionic liquids Diels-Alder reaction Reaction density functional theory

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Attenuation characteristics of impact-induced seismic wave in deep tunnels:An in situ investigation based on pendulum impact test

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第2期14卷 494-504页

作者： Jian Wu Quansheng Liu Xiaoping Zhang Chuiyi Zhou Xin Yin weiqiang xie Xu Liang Jiaqi Huang PowerChina Huadong Engineering Corporation Limited Hangzhou311122China Key Laboratory of Safety for Geotechnical and Structural Engineering of Hubei Province School of Civil EngineeringWuhan UniversityWuhan430072China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China Hangzhou Urban Infrastructure Construction Management Center Hangzhou310009China

The radiated seismic energy is an important index for the intensity assessment of microseismic(MS)events and the early warning of dynamic ***,the energy of MS signals is significantly attenuated due to the heterogeneity and viscous damping of rock ***,the study on attenuation characteristics of MS signals in underground engineering has practical significance for the accurately estimation of radiated seismic *** on a pendulum impact test facility and MS monitoring system,an in situ investigation was carried out to explore attenuation characteristics at a deep *** results show that the seismic energy and peak particle velocity(PPV)attenuation are exponentially related to the propagation *** attenuation coefficient of energy is larger than that of *** the increase in the input impact-energy,the seismic energy attenuation coefficient decreases as a power *** empirical relationship between energy attenuation coefficient and wave impedance of rock mass was established in this ***,the time-frequency characteristics and energy distribution laws of impact-induced signals were investigated by the continuous wavelet transform(CWT)and wavelet packet analyses,*** dominant frequency of signals decreases gradually as the propagation distance *** on the energy attenuation characteristics,a new method was proposed to calculate the released source energy of MS events in the *** study can provide an insight into energy attenuation characteristics of seismic waves and references for attenuation correction in seismic energy calculation.

关键词： Attenuation characteristics Microseismic monitoring Pendulum impact facility Seismic energy Deep tunnels

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Submilliwatt, widely tunable coherent microcomb generation with feedback-free operation

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Advanced Photonics 2023年第3期5卷 144-154页

作者： Haowen Shu Lin Chang Chenghao Lao Bitao Shen weiqiang xie Xuguang Zhang Ming Jin Yuansheng Tao Ruixuan Chen Zihan Tao Huajin Chang Shaohua Yu Qifan Yang Xingjun Wang John E.Bowers Peking University School of ElectronicsState Key Laboratory of Advanced Optical Communication Systems and NetworksBeijingChina University of California Santa BarbaraDepartment of Electrical and Computer EngineeringSanta BarbaraCaliforniaUnited States Peking University School of PhysicsState Key Laboratory for Artificial Microstructure and Mesoscopic PhysicsBeijingChina Peng Cheng Laboratory ShenzhenChina Peking University Frontiers Science Center for Nano-OptoelectronicsBeijingChina

Microcombs are revolutionizing optoelectronics by providing parallel, mutually coherent wavelengthchannels for time-frequency metrology and information processing. To implement this essential function inintegrated photonic systems, it is desirable to drive microcombs directly with an on-chip laser in a simpleand flexible way. However, two major difficulties have prevented this goal: (1) generating mode-lockedcomb states usually requires a significant amount of pump power and (2) the requirement to align laser andresonator frequency significantly complicates operation and limits the tunability of the comb lines. Here, weaddress these problems by using microresonators on an AlGaAs on-insulator platform to generate dark-pulsemicrocombs. This highly nonlinear platform dramatically relaxes fabrication requirements and leads to arecord-low pump power of <1 mW for coherent comb generation. Dark-pulse microcombs facilitated bythermally controlled avoided mode crossings are accessed by direct distributed feedback laser *** any feedback or control circuitries, the comb shows good coherence and stability. With around150 mW on-chip power, this approach also leads to an unprecedentedly wide tuning range of over one freespectral range (97.5 GHz). Our work provides a route to realize power-efficient, simple, and reconfigurablemicrocombs that can be seamlessly integrated with a wide range of photonic systems.

关键词： dark-pulse microcomb direct pumping scheme widely tunable source

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Structural insight into the dual-antagonistic mechanism of AB928 on adenosine A_(2)receptors

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Science China(Life Sciences) 2024年第5期67卷 986-995页

作者： Yuan Weng Xinyu Yang Qiansen Zhang Ying Chen Yueming Xu Chenyu Zhu Qiong xie Yonghui Wang Huaiyu Yang Mingyao Liu weiqiang Lu Gaojie Song Shanghai Key Laboratory of Regulatory Biology Institute of Biomedical Sciences and School of Life SciencesEast China Normal UniversityShanghai 200241China Department of Medicinal Chemistry School of PharmacyFudan UniversityShanghai 201203China

The adenosine subfamily G protein-coupled receptors A_(2A)R and A_(2B)R have been identified as promising cancer immunotherapy *** of the A_(2A)R/A_(2B)R dual antagonists,AB928,has progressed to a phaseⅡclinical trial to treat rectal ***,the precise mechanism underlying its dual-antagonistic properties remains ***,we report crystal structures of the A_(2A)R complexed with AB928 and a selective A_(2A)R antagonist *** structures revealed a common binding mode on A_(2A)R,wherein the ligands established extensive interactions with residues from the orthosteric and secondary *** contrast,the cAMP assay and A_(2A)R and A_(2B)R molecular dynamics simulations indicated that the ligands adopted distinct binding modes on A_(2B)*** analysis of their chemical structures suggested that AB928 readily adapted to the A_(2B)R pocket,while 2-118 did not due to intrinsic *** disparity potentially accounted for the difference in inhibitory efficacy between A_(2B)R and A_(2A)*** study serves as a valuable structural template for the future development of selective or dual inhibitors targeting A_(2A)R/A_(2B)R for cancer therapy.

关键词： adenosine receptor A2AR A2BR inhibitor dual-antagonism drug discovery

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