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微震监测技术及其在煤矿的应用现状与展望

煤炭学报 2017年第S1期42卷 83-96页

作者：李楠王恩元 ge mao-chen 中国矿业大学煤炭资源与安全开采国家重点实验室江苏徐州221116 中国矿业大学安全工程学院江苏徐州221116 密苏里科技大学采矿与核工程系密苏里州罗拉65409

微震监测技术是利用煤岩破裂产生的微震信息来研究煤岩结构和稳定性的一种实时、动态、连续的地球物理监测方法,主要包含微震传感器台网优化、微震信号识别及到时拾取、波速模型、微震波形特征、震源定位与成像、震源机制、微震监测预... 详细信息

微震监测技术是利用煤岩破裂产生的微震信息来研究煤岩结构和稳定性的一种实时、动态、连续的地球物理监测方法,主要包含微震传感器台网优化、微震信号识别及到时拾取、波速模型、微震波形特征、震源定位与成像、震源机制、微震监测预警等。近30 a来,微震监测技术在煤矿安全高效生产中得到了广泛应用。煤岩破坏过程中的微震波形特征、震源定位、矿震活动性规律、冲击地压微震监测预警等方面取得了一系列研究成果;在煤与瓦斯突出、突水、煤岩水力压裂、井下救援的微震监测方面进行了初步研究和探索,并取得了一些有益研究结果。然而煤矿微震监测仍然有很多问题需要进行系统深入研究,主要包含如下:煤岩不同破坏类型,特别是流体作用或参与下的微震波形信号特征;高精度的微震信号自动识别和到时自动拾取;基于微震监测的被动成像理论与技术;煤岩动力灾害前兆信息智能感知和多元信息融合监控预警体系;煤岩水力压裂裂缝微震监测与定位成像技术等。同时还应加快发展和完善具有自主知识产权的高性能、高精度、高可靠性的微震监测系统。

关键词：煤矿微震监测技术震源定位煤岩动力灾害监测预警水力压裂监测微震成像展望

Meridional deflection of global eddy propagation derived from tandem altimetry: Mechanism and implication

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Science China Earth Sciences 2024年第3期67卷 811-825页

作者： ge chen Xiaoyan chen Frontiers Science Center for Deep Ocean Multispheres and Earth System School of Marine TechnologyOcean University of ChinaQindao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQindao 266237China

A common view on meridional deflection of eddy propagation is poleward for cyclones and equatorward for anticyclones. This widely accepted polarity-sensitive pattern has been increasingly undermined given that it is systematically violated on both zonal and regional scales as recently reported. Here, we approach the problem by exploring these violations in terms of eddy effects of spatiotemporal geostrophy, thermal fading, and flow dragging, yielding the following main conclusions.(1) The polarity-dependent deflection discrepancy is a pseudo feature resulting from a biased fit to the normalized eddy tracks which are spatially asymmetric(though azimuthally symmetric) between the two signs;Instead, the primary pattern of eddy deflection appears to be geographically correlated and polarity independent.(2) geostrophic adjustment plays a critical role in defining the meridional movement of an eddy. Specifically, a consistent poleward(equatorward) trajectory bending of spatially(temporally) ageostrophic eddies is observed irrespective of their polarity.(3) The mechanism of eddy deflection is also determined by its zonal propagation direction. Westward propagating eddies are substantially affected by thermal fading, while opposite ones by flow dragging. A realistic and comprehensive understanding of eddy deflection mechanisms serves as a significant contribution to the prediction of eddy trajectory, and the protection of ocean environment.

关键词： Mesoscale eddies Eddy propagation Eddy meridional deflection Satellite observation geostrophic adjustment

First wetland mapping at 10-m spatial resolution in South America using multi-source and multi-feature remote sensing data

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Science China Earth Sciences 2024年第10期67卷 3252-3269页

作者： Weiwei SUN Gang YANG Yuling HUANG Dehua mao Ke HUANG Lin ZHU Xiangchao MENG Tian FENG Chao chen Yong ge Department of geography and Spatial Information Techniques Ningbo UniversityNingbo 315211China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences&Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Natural Resources and Planning Bureau Shanghai Pudong New DistrictShanghai 200100China Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China Faculty of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211China School of geography Science and geomatics Engineering Suzhou University of Science and TechnologySuzhou 215009China

Wetland degradation has been accelerating in recent years globally. Accurate information on the geographic distribution and categories of wetlands is essential for their conservation and management. Despite being the world′s fourth largest continent, South America has limited research on wetland mapping, and there is currently no available map that provides comprehensive information on wetland distribution and categories in the region. To address this issue, we used Sentinel-1, Sentinel-2 and SRTM data, developed a sample collection method and a wetland mapping method with a collection of multi-source features such as optical features, polarization features and shape features for South American wetlands. We produced a 10-m resolution wetland map based on the Google Earth Engine(geE) platform. Our Level-1 wetland cover map accurately captured six wetland sub-categories with an overall accuracy of 96.24% and a kappa coefficient of 0.8649, while our Level-2 water cover map included five sub-categories with an overall accuracy of 97.23% and a kappa coefficient of0.9368. The results show that the total area of existing wetlands in South America is approximately 1,737,000 km~2, which is6.8% of the total land area. Among the ten wetland categories, shallow sea had the largest area(960,527.4 km~2), while aquaculture ponds had the smallest area 1513.6 km~2. Swamp had the second largest area(306,240.1 km~2). Brazil, Argentina,Venezuela, Bolivia, and Colombia were found to have the largest wetland areas, with Brazil and Colombia having the most diverse wetland categories. This product can serve as baseline data for subsequent monitoring, management, and conservation of South American wetlands.

关键词： Wetland mapping Google Earth Engine Sentinel imagery South America

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Evaluation of microRNA expression profiles in human sperm frozen using permeable cryoprotectant-free droplet vitrification and conventional methods

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Asian Journal of Andrology 2024年第4期26卷 366-376页

作者： Li-Xin Zhang Jing mao Yan-Dong Zhou Guang-Yao mao Run-Fa Guo Hong-Shan ge Xia chen Department of Histology and Embryology Medical SchoolNantong UniversityNantong 226001China Department of Reproductive Medicine The Affiliated Taizhou People’s Hospital of Nanjing Medical UniversityTaizhou School of Clinical MedicineNanjing Medical UniversityTaizhou 225300China.

For sperm cryopreservation,the conventional method,which requires glycerol,has been used for a long *** addition,the permeable cryoprotectant-free vitrification method has been continuously *** the differences of cryopreservation effects between the two methods have being studied,differences in microRNA(miRNA)profiles between them remain *** this study,we investigated the differences in miRNA expression profiles among conventional freezing sperm,droplet vitrification freezing sperm and fresh human *** also analyzed the differences between these methods in terms of differentially expressed miRNAs(DEmiRs)related to early embryonic development and paternal *** results showed no significant differences between the cryopreservation methods in terms of sperm motility ratio,plasma membrane integrity,DNA integrity,mitochondrial membrane potential,acrosome integrity,and ultrastructural ***,sperm miRNA-sequencing showed differences between the two methods in terms of the numbers of DEmiRs(28 and 19 with vitrification using a nonpermeable cryoprotectant and the conventional method,respectively)in postthaw and fresh sperm *** related to early embryonic development and paternal epigenetics mainly included common DEmiRs between the *** results showed that the differences between conventional freezing and droplet vitrification were minimal in terms of miRNA expression related to embryonic development and *** in sperm miRNA expression due to freezing are not always detrimental to embryonic *** study compared differences in miRNA expression profiles before and after cryopreservation between cryopreservation by conventional and vitrification *** offers a new perspective to evaluate various methods of sperm cryopreservation.

关键词： cryopreservation cryoprotectant-free vitrification early embryonic development paternal epigenetic inheritance sperm miRNAs sucrose

Constraint Learning-based Optimal Power Dispatch for Active Distribution Networks with Extremely Imbalanced Data

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 51-65页

作者： Yonghua Song ge chen Hongcai Zhang State Key Laboratory of Internet of Things for Smart City and Department of Electrical and Computer Engineering University of MacaoMacao 999078China School of Electrical and Computer Engineering Purdue UniversityWest LafayetteIN 47907 USA

Transition towards carbon-neutral power systems has necessitated optimization of power dispatch in active distribution networks(ADNs)to facilitate integration of distributed renewable *** to unavailability of network topology and line impedance in many distribution networks,physical model-based methods may not be applicable to their *** tackle this challenge,some studies have proposed constraint learning,which replicates physical models by training a neural network to evaluate feasibility of a decision(i.e.,whether a decision satisfies all critical constraints or not).To ensure accuracy of this trained neural network,training set should contain sufficient feasible and infeasible ***,since ADNs are mostly operated in a normal status,only very few historical samples are ***,the historical dataset is highly imbalanced,which poses a significant obstacle to neural network *** address this issue,we propose an enhanced constraint learning ***,it leverages constraint learning to train a neural network as surrogate of ADN's ***,it introduces Synthetic Minority Oversampling Technique to generate infeasible samples to mitigate imbalance of historical *** incorporating historical and synthetic samples into the training set,we can significantly improve accuracy of neural ***,we establish a trust region to constrain and thereafter enhance reliability of the *** confirm the benefits of the proposed method in achieving desirable optimality and feasibility while maintaining low computational complexity.

关键词： Deep learning demand response distribution networks imbalanced data optimal power flow

STABLE RECOVERY OF SPARSELY CORRUPTED SIGNALS THROUGH JUSTICE PURSUIT DE-NOISING

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Journal of Computational Mathematics 2024年第1期42卷 271-288页

作者： Ningning Li Wengu chen Huanmin ge Institute of Applied Physics and Computational Mathematics Beijing 100088China Beijing Sport University Beijing 100084China

This paper considers a corrupted compressed sensing problem and is devoted to recover signals that are approximately sparse in some general dictionary but corrupted by a combination of interference having a sparse representation in a second general dictionary and measurement *** provide new restricted isometry property(RIP)analysis to achieve stable recovery of sparsely corrupted signals through Justice Pursuit De-Noising(JPDN)with an additional *** main tool is to adapt a crucial sparse decomposition technique to the analysis of the Justice Pursuit *** proposed RIP condition improves the existing representative *** simulations are provided to verify the reliability of the JPDN model.

关键词： Justice Pursuit De-Noising Restricted isometry property Corrupted compressed sensing Signal recovery

Numerical Simulation of the Settling Flux of Biodeposition in a Bay with Cage Culture Through Similarity Theory and a Simplified Pollution Source

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Journal of Ocean University of China 2024年第1期23卷 247-254页

作者： LIU Yao chen Yifan ge Changzi Marine College Shandong UniversityWeihai 264209China

The settling flux of biodeposition affects the environmental quality of cage culture areas and determines their environmental carrying *** and effective simulation of the settling flux of biodeposition is extremely important for determining the spatial distribution of ***,biodeposition in cage culture areas without specific emission rules can be simplified as point source *** is a fluid simulation software that can simulate the dispersion of particulate matter simply and *** on the simplification of pollution sources and bays,the settling flux of biodeposition can be easily and effectively simulated by Fluent fluid *** the present work,the feasibility of this method was evaluated by simulation of the settling flux of biodeposition in Maniao Bay,Hainan Province,China,and 20 sampling sites were selected for determining the settling *** sampling sites P1,P2,P3,P4,P5,Z1,Z2,Z3,Z4,A1,A2,A3,A4,B1,B2,C1,C2,C3 and C4,the measured settling fluxes of biodeposition were 26.02,15.78,10.77,58.16,6.57,72.17,12.37,12.11,106.64,150.96,22.59,11.41,18.03,7.90,19.23,7.06,11.84,5.19 and 2.57 g d^(−1)m^(−2),*** simulated settling fluxes of biodeposition at the corresponding sites were 16.03,23.98,8.87,46.90,4.52,104.77,16.03,8.35,180.83,213.06,39.10,17.47,20.98,9.78,23.25,7.84,15.90,6.06 and 1.65 g d^(−1)m^(−2),*** was a positive correlation between the simulated settling fluxes and measured ones(R=0.94,P=2.22×10^(−9)<0.05),which implies that the spatial differentiation of biodeposition flux was well ***,the posterior difference ratio of the simulation was 0.38,and the small error probability was 0.94,which means that the simulated results reached an acceptable level from the perspective of relative ***,if nonpoint source pollution is simplified to point source pollution and open waters are simplified based on similarity theory,the setting flux of biodeposition i

关键词： fluent fluid simulation software pollution source simplification posterior difference ratio similarity theory Spear-man correlation

Metal-organic-framework-derived copper-based catalyst for multicomponent C-S coupling reaction

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Chinese Journal of Chemical Engineering 2024年第6期70卷 1-8页

作者： Lixin chen Hui Zhang Linxi Hou Xin ge Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China Department of Materials-Oriented Chemical Engineering School of Chemical EngineeringFuzhou UniversityFuzhou 350116China Qingyuan Innovation Laboratory Quanzhou 362801China

Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and ***,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling *** this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of ***,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.

关键词： Design Copper-based metal-organic frameworks (Cu-MOFs) Adsorption C-S coupling reaction Multiphase reaction

Constructal design of a rectangular parallel phase change microchannel in a three-dimensional electronic device

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Science China(Technological Sciences) 2024年第5期67卷 1381-1390页

作者： ZHANG JiWen FENG HuiJun chen Lingen ge YanLin Institute of Thermal Science and Power Engineering Wuhan Institute of TechnologyWuhan430205China College of Power Engineering Naval University of EngineeringWuhan430033China Hubei Provincial Engineering Technology Research Center of Green Chemical Equipment Wuhan430205China School of Mechanical&Electrical Engineering Wuhan Institute of TechnologyWuhan430205China

Based on constructal theory,a rectangular parallel phase change microchannel model in a three-dimensional electronic device(TDED)is established with R134a as the cooling *** on the minimization of a complex function(CF)composed of linear weighting sum of maximum temperature difference and pumping power consumption,constructal design of the TDED is conducted first;and then,maximum temperature difference and pumping power consumption are minimized by non-dominated sorting genetic algorithm-II *** results reveal that there exist an optimal mass flow rate(0.0012 kg/s)and a quadratic optimal aspect ratio(AR)(0.39)of the microchannel which lead to quadratic minimum CF(0.817).Compared with the original value,the CF after optimization is reduced by 18.34%.Reducing the inlet temperature of cooling fluid and microchannel number appropriately can help to enhance the overall performance of *** using the artificial neural network and genetic algorithms in the toolboxes of Matlab software,the optimal AR gained in the Pareto solution set is located between 0.2–*** smallest deviation index among three discussed strategies is 0.346,and the corresponding optimal AR is 0.413,which is selected as the optimal design strategy of the microchannel in the TDED under multiple *** findings in this study can serve as theoretical guides for thermal designs of electronic devices.

关键词： constructal theory parallel microchannel evaporation phase change three-dimensional electronic device multi-objective optimization artificial neural network