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The Analysis of Gauss Radial Basis Functions and Its Application in Locating Olivine on the Moon
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作者 SONG Shicang SONG Xiaoyuan SONG Shuhan 《应用数学》 北大核心 2026年第1期173-181,共9页
Gauss radial basis functions(GRBF)are frequently employed in data fitting and machine learning.Their linear independence property can theoretically guarantee the avoidance of data redundancy.In this paper,one of the m... Gauss radial basis functions(GRBF)are frequently employed in data fitting and machine learning.Their linear independence property can theoretically guarantee the avoidance of data redundancy.In this paper,one of the main contributions is proving this property using linear algebra instead of profound knowledge.This makes it easy to read and understand this fundamental fact.The proof of linear independence of a set of Gauss functions relies on the constructing method for one-dimensional space and on the deducing method for higher dimensions.Additionally,under the condition of preserving the same moments between the original function and interpolating function,both the interpolating existence and uniqueness are proven for GRBF in one-dimensional space.The final work demonstrates the application of the GRBF method to locate lunar olivine.By combining preprocessed data using GRBF with the removing envelope curve method,a program is created to find the position of lunar olivine based on spectrum data,and the numerical experiment shows that it is an effective scheme. 展开更多
关键词 Gauss function Radial basis function Machine learning Lunar olivine locating Data fitting
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Visiting Salzbung
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作者 Ruth Devlin 《空中英语教室(初级版.大家说英语)》 2026年第1期6-9,50,共5页
Salzburg is a beautiful city in Austria.It has old buildings,pretty streets and big mountains all around.The scenery is amazing!The famous movie The Sound of Music was filmed there.Many people visit Salzburg to see th... Salzburg is a beautiful city in Austria.It has old buildings,pretty streets and big mountains all around.The scenery is amazing!The famous movie The Sound of Music was filmed there.Many people visit Salzburg to see the locations from the movie.Some even do interviews there to ask people their feelings about the movie.One famous location from the movie is the Mirabell Gardens.The actors sang the song"Do-Re-Mi"there.The gardens have colorful flowers,statues and fountains.Salzburg is a fun and exciting place to visit and explore. 展开更多
关键词 mirabell gardensthe sound music Mirabell Gardens Austria Salzburg tourist attractions movie locations
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Locator联合杆支持上颌种植义齿临床观察
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作者 付俊 郑嘉宝 +1 位作者 常攀辉 陈明 《中华老年口腔医学杂志》 2025年第5期357-362,共6页
目的总结回顾铸造/切削杆联合Locator附着体种植支持式覆盖义齿修复上颌无牙颌或多数牙缺失的临床效果。方法选择首都医科大学附属北京口腔医院2014年1月至2023年1月的门诊上颌无牙颌或仅存个别天然牙的老年患者8例,分别植入5~6枚种植体... 目的总结回顾铸造/切削杆联合Locator附着体种植支持式覆盖义齿修复上颌无牙颌或多数牙缺失的临床效果。方法选择首都医科大学附属北京口腔医院2014年1月至2023年1月的门诊上颌无牙颌或仅存个别天然牙的老年患者8例,分别植入5~6枚种植体,上颌双侧后牙区分别制作刚性连接铸造或切削杆,前牙区种植体Locator附着体辅助固位,为8例患者制作种植支持式覆盖义齿,随访观察3~10年,定期复查,了解患者义齿佩戴满意度、咀嚼功能。X线片观察种植体周骨吸收状况。结果8例患者共46枚种植体无松动及脱落,种植体周无异常骨吸收。义齿固位支持力长期保持稳定,患者对功能恢复、外观及佩戴舒适性满意。结论运用铸造/切削杆联合Locator附着体种植支持式覆盖义齿修复上颌无牙颌取得了长期稳定的美观及功能效果。义齿制作工艺简便、固位力适中且长期稳定,值得临床进一步推广及研究。 展开更多
关键词 种植覆盖义齿 上颌无牙颌 杆附着 Locator附着体
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Nomenclature and location of acupuncture points for laboratory animals Part 3:Mouse 被引量:3
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作者 《World Journal of Acupuncture-Moxibustion》 2025年第2期160-162,共3页
This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 3:Mouse.This standard was released by the China Associ... This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 3:Mouse.This standard was released by the China Association of Acupuncture and Moxibustion on May 15,2020,implemented on October 31,2020,and published by Standards Press of China.The standard was drafted by the Institute of Acupuncture and Moxibustion,China Academy of Chinese Medical Sciences,and the Nanjing University of Chinese Medicine.Principal draftsmen:Xiang-hong JING and Xing-bang HUA.Participating draftsmen:Wan-zhu BAI,Bin XU,Dong-sheng XU,Yi GUO,Tie-ming MA,Xin-jun WANG,and Sheng-feng LU. 展开更多
关键词 acupuncture points STANDARD MOUSE NOMENCLATURE location acupuncture points association standardt caam LOCATION acupuncture moxibustion
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Research on acupuncture robots based on the OptiTrack motion capture system and a robotic arm 被引量:2
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作者 HE Ling YANG Hui +4 位作者 LI Kang WANG Junwen SUN Zhibo YANG Jinsheng ZHANG Jing 《Journal of Traditional Chinese Medicine》 2025年第1期201-212,共12页
OBJECTIVE:To propose an automatic acupuncture robot system for performing acupuncture operations.METHODS:The acupuncture robot system consists of three components:automatic acupoint localization,acupuncture manipulati... OBJECTIVE:To propose an automatic acupuncture robot system for performing acupuncture operations.METHODS:The acupuncture robot system consists of three components:automatic acupoint localization,acupuncture manipulations,and De Qi sensation detection.The OptiTrack motion capture system is used to locate acupoints,which are then translated into coordinates in the robot control system.A flexible collaborative robot with an intelligent gripper is then used to perform acupuncture manipulations with high precision.In addition,a De Qi sensation detection system is proposed to evaluate the effect of acupuncture.To verify the stability of the designed acupuncture robot,acupoints'coordinates localized by the acupuncture robot are compared with the Gold Standard labeled by a professional acupuncturist using significant level tests.RESULTS:Through repeated experiments for eight acupoints,the acupuncture robot achieved a positioning error within 3.3 mm,which is within the allowable range of needle extraction and acupoint insertion.During needle insertion,the robot arm followed the prescribed trajectory with a mean deviation distance of 0.02 mm and a deviation angle of less than 0.15°.The results of the lifting thrusting operation in the Xingzhen process show that the mean acupuncture depth error of the designed acupuncture robot is approximately 2 mm,which is within the recommended depth range for the Xingzhen operation.In addition,the average detection accuracy of the De Qi keywords is 94.52%,which meets the requirements of acupuncture effect testing for different dialects.CONCLUSION:The proposed acupuncture robot system streamlines the acupuncture process,increases efficiency,and reduces practitioner fatigue,while also allowing for the quantification of acupuncture manipulations and evaluation of therapeutic effects.The development of an acupuncture robot system has the potential to revolutionize low back pain treatment and improve patient outcomes. 展开更多
关键词 acupuncture robot acupuncture quantification acupoint location De Qi detection
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Nomenclature and location of acupuncture points for laboratory animals Part 2 被引量:1
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作者 《World Journal of Acupuncture-Moxibustion》 2025年第2期163-165,共3页
This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 2:Rat.This standard was released by the China Associat... This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 2:Rat.This standard was released by the China Association of Acupuncture and Moxibustion on May 15,2020,implemented on October 31,2020,and published by Standards Press of China.The standard was drafted by the Institute of Acupuncture and Moxibustion,China Academy of Chinese Medical Sciences,and the Nanjing University of Chinese Medicine.Principal draftsmen:Xiang-hong JING and Xing-bang HUA.Participating draftsmen:Wan-Zhu BAI,Bin XU,Dong-sheng XU,Yi GUO,Tie-ming MA,Xin-jun WANG,and Sheng-feng LU. 展开更多
关键词 acupuncture points STANDARD NOMENCLATURE rat association standardt caam LOCATION acupuncture moxibustion
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Real-time monitoring and analysis of hydraulic fracturing in surface well using microseismic technology:Case insights and methodological advances 被引量:1
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作者 Yanan Qian Ting Liu +6 位作者 Cheng Zhai Hongda Wen Yuebing Zhang Menghao Zheng Hexiang Xu Dongyong Xing Xinke Gan 《International Journal of Mining Science and Technology》 2025年第4期619-638,共20页
Through a case analysis,this study examines the spatiotemporal evolution of microseismic(MS)events,energy characteristics,volumetric features,and fracture network development in surface well hydraulic fracturing.A tot... Through a case analysis,this study examines the spatiotemporal evolution of microseismic(MS)events,energy characteristics,volumetric features,and fracture network development in surface well hydraulic fracturing.A total of 349 MS events were analyzed across different fracturing sections,revealing significant heterogeneity in fracture propagation.Energy scanning results showed that cumulative energy values ranged from 240 to 1060 J across the sections,indicating notable differences.Stimulated reservoir volume(SRV)analysis demonstrated well-developed fracture networks in certain sections,with a total SRV exceeding 1540000 m^(3).The hydraulic fracture network analysis revealed that during the midfracturing stage,the density and spatial extent of MS events significantly increased,indicating rapid fracture propagation and the formation of complex networks.In the later stage,the number of secondary fractures near fracture edges decreased,and the fracture network stabilized.By comparing the branching index,fracture length,width,height,and SRV values across different fracturing sections,Sections No.1 and No.8 showed the best performance,with high MS event densities,extensive fracture networks,and significant energy release.However,Sections No.4 and No.5 exhibited sparse MS activity and poor fracture connectivity,indicating suboptimal stimulation effectiveness. 展开更多
关键词 Hydraulic fracturing Microseismic Source location Energy scanning Fracture network
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Prognosis in stage II colon cancer:Expanding the horizons of risk factors 被引量:1
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作者 María Belén Novoa Díaz Claudia Gentili +1 位作者 María Julia Martín Pedro Carriere 《World Journal of Gastrointestinal Oncology》 2025年第2期28-34,共7页
we critically review the authors’perspective and analyze the relevance of the results obtained in the original article of clinical research by Liu et al.We consider that additional factors associated with colon cance... we critically review the authors’perspective and analyze the relevance of the results obtained in the original article of clinical research by Liu et al.We consider that additional factors associated with colon cancer progression have recently been described in extensive clinical research,and should be included in this analysis to achieve a more accurate prognosis.These factors include inflammation,gut microbiota composition,immune status and nutritional balance,as they influence the post-surgical survival profile of patients with stage II colorectal cancer.We also address the clinical implementation and limitations of these analyses.Evaluation of the patient´s entire context is essential for selection of the most appropriate therapy. 展开更多
关键词 Risk factor PROGNOSIS Colon cancer Inflammation markers Tumor location
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Topographic factors associated with anterior chamber angle narrowing in patients with keratoconus 被引量:1
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作者 Hamed Soltan-Dehghan Abdollah Farzaneh +2 位作者 Hassan Hashemi Payam Nabovati Mehdi Khabazkhoob 《International Journal of Ophthalmology(English edition)》 2025年第1期67-73,共7页
AIM:To identify topographic determinants of the anterior chamber angle(ACA)in patients with keratoconus(KCN).METHODS:Four hundred and ten eyes of 294 patients with KCN were recruited for this study.First,complete ocul... AIM:To identify topographic determinants of the anterior chamber angle(ACA)in patients with keratoconus(KCN).METHODS:Four hundred and ten eyes of 294 patients with KCN were recruited for this study.First,complete ocular examinations were performed for all patients,including visual acuity measurement,refraction,and slit-lamp biomicroscopy.Then,all participants underwent corneal imaging by the Oculus Pentacam HR.RESULTS:The mean age of the participants was 32.40±8.52y(15-60y)and 69.5%of them were male.The mean ACA was 38.47°±5.75°(range:14.40°to 56.50°)in the whole sample,38.24°±6.00°in males,and 38.98°±5.11°in females(P=0.447).The mean ACA was significantly different among different groups of cone morphology,as patients with nipple cones showed the lowest mean ACA.Moreover,there were statistically significant differences in the mean ACA among different groups of cone locations,with patients having central cones exhibiting the lowest mean ACA(P<0.001).Anterior and posterior Q values were significantly,directly correlated with ACA(anterior Q:r=0.122,P=0.014,posterior Q:r=0.192,P<0.001).CONCLUSION:This study provides critical insights into the risk factors for ACA narrowing in KCN patients,which is essential for planning intraocular surgeries.Patients with nipple and central cones exhibited the most significant ACA narrowing.Additionally,more negative Q-values are associated with increased ACA narrowing,highlighting the need for targeted diagnostic and therapeutic strategies. 展开更多
关键词 KERATOCONUS anterior chamber angle cone morphology cone location
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Earthquake monitoring and high-resolution velocity tomography for the central Longmenshan fault zone by a temporary dense seismic array 被引量:1
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作者 ShaoBo Yang HaiJiang Zhang +4 位作者 MaoMao Wang Ji Gao Shuaijun Wang BaoJin Liu XiWei Xu 《Earth and Planetary Physics》 2025年第2期239-252,共14页
The Longmenshan(LMS)fault zone is located at the junction of the eastern Tibetan Plateau and the Sichuan Basin and is of great significance for studying regional tectonics and earthquake hazards.Although regional velo... The Longmenshan(LMS)fault zone is located at the junction of the eastern Tibetan Plateau and the Sichuan Basin and is of great significance for studying regional tectonics and earthquake hazards.Although regional velocity models are available for the LMS fault zone,high-resolution velocity models are lacking.Therefore,a dense array of 240 short-period seismometers was deployed around the central segment of the LMS fault zone for approximately 30 days to monitor earthquakes and characterize fine structures of the fault zone.Considering the large quantity of observed seismic data,the data processing workflow consisted of deep learning-based automatic earthquake detection,phase arrival picking,and association.Compared with the earthquake catalog released by the China Earthquake Administration,many more earthquakes were detected by the dense array.Double-difference seismic tomography was adopted to determine V_(p),V_(s),and V_(p)/V_(s)models as well as earthquake locations.The checkerboard test showed that the velocity models have spatial resolutions of approximately 5 km in the horizontal directions and 2 km at depth.To the west of the Yingxiu–Beichuan Fault(YBF),the Precambrian Pengguan complex,where most of earthquakes occurred,is characterized by high velocity and low V_(p)/V_(s)values.In comparison,to the east of the YBF,the Upper Paleozoic to Jurassic sediments,where few earthquakes occurred,show low velocity and high V_(p)/V_(s)values.Our results suggest that the earthquake activity in the LMS fault zone is controlled by the strength of the rock compositions.When the high-resolution velocity models were combined with the relocated earthquakes,we were also able to delineate the fault geometry for different faults in the LMS fault zone. 展开更多
关键词 Longmenshan fault zone dense seismic array deep learning double-difference seismic tomography seismic velocity model earthquake locations fault geometry
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Improving DOA estimation of GNSS interference through sparse non-uniform array reconfiguration 被引量:1
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作者 Rongling LANG Hao XU +3 位作者 Fei GAO Zewen TANG Zhipeng WANG Amir HUSSAIN 《Chinese Journal of Aeronautics》 2025年第8期104-118,共15页
Interference significantly impacts the performance of the Global Navigation Satellite Systems(GNSS),highlighting the need for advanced interference localization technology to bolster anti-interference and defense capa... Interference significantly impacts the performance of the Global Navigation Satellite Systems(GNSS),highlighting the need for advanced interference localization technology to bolster anti-interference and defense capabilities.The Uniform Circular Array(UCA)enables concurrent estimation of the Direction of Arrival(DOA)in both azimuth and elevation.Given the paramount importance of stability and real-time performance in interference localization,this work proposes an innovative approach to reduce the complexity and increase the robustness of the DOA estimation.The proposed method reduces computational complexity by selecting a reduced number of array elements to reconstruct a non-uniform sparse array from a UCA.To ensure DOA estimation accuracy,minimizing the Cramér-Rao Bound(CRB)is the objective,and the Spatial Correlation Coefficient(SCC)is incorporated as a constraint to mitigate side-lobe.The optimization model is a quadratic fractional model,which is solved by Semi-Definite Relaxation(SDR).When the array has perturbations,the mathematical expressions for CRB and SCC are re-derived to enhance the robustness of the reconstructed array.Simulation and hardware experiments validate the effectiveness of the proposed method in estimating interference DOA,showing high robustness and reductions in hardware and computational costs associated with DOA estimation. 展开更多
关键词 GNSS interference location Direction of arrival estimation Adaptive reconfigurable array Cramér-Raobound Quadratic fractional programming
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Identification of failure behaviors of underground structures under dynamic loading using machine learning 被引量:1
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作者 Chun Zhu Yingze Xu +5 位作者 Manchao He Yujing Jiang Murat Karakus Lihua Hu Yalong Jiang Fuqiang Ren 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第1期414-431,共18页
Understanding the dynamic responses of hard rocks is crucial during deep mining and tunneling activities and when constructing nuclear waste repositories. However, the response of deep massive rocks with openings of d... Understanding the dynamic responses of hard rocks is crucial during deep mining and tunneling activities and when constructing nuclear waste repositories. However, the response of deep massive rocks with openings of different shapes and orientations to dynamic loading is not well understood. Therefore, this study investigates the dynamic responses of hard rocks of deep underground excavation activities. Split Hopkins Pressure Bar (SHPB) tests on granite with holes of different shapes (rectangle, circle, vertical ellipse (elliptical short (ES) axis parallel to the impact load direction), and horizontal ellipse (elliptical long (EL) axis parallel to the impact load direction)) were carried out. The influence of hole shape and location on the dynamic responses was analyzed to reveal the rocks' dynamic strengths and cracking characteristics. We used the ResNet18 (convolutional neural network-based) network to recognize crack types using high-speed photographs. Moreover, a prediction model for the stress-strain response of rocks with different openings was established using Deep Neural Network (DNN). The results show that the dynamic strengths of the granite with EL and ES holes are the highest and lowest, respectively. The strength-weakening coefficient decreases first and then increases with an increase of thickness-span ratio (h/L). The weakening of the granite with ES holes is the most obvious. The ResNet18 network can improve the analyzing efficiency of the cracking mechanism, and the trained model's recognition accuracy reaches 99%. Finally, the dynamic stress-strain prediction model can predict the complete stress-strain curve well, with an accuracy above 85%. 展开更多
关键词 Dynamic mechanical response Cracking mode Hole shape/location effect Deep Neural Network(DNN) Stress-strain prediction
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A new predictive based secure geographic routing strategy for UAV network under location spoofing attack
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作者 Zihao ZHOU Jie TANG +3 位作者 Zhutian YANG Junyuan FAN Xiaokai SONG Kai Kit WONG 《Chinese Journal of Aeronautics》 2025年第10期47-58,共12页
Unmanned aerial vehicle(UAV)swarm network consisting of a collection of micro UAVs can be used for many applications.It is well established that packet routing is a fundamental problem to achieve UAV collaboration.How... Unmanned aerial vehicle(UAV)swarm network consisting of a collection of micro UAVs can be used for many applications.It is well established that packet routing is a fundamental problem to achieve UAV collaboration.However,the highly dynamic nature of UAVs,frequently changing network topologies and security issues,poses significant challenges to packet forwarding in UAV networks.The existing topology-based routing protocols are not well suited in UAV network due to their high controlling overhead or excessive end-to-end delay.Geographic routing is regarded as a promising solution,as it only requires local information.In order to enhance the accuracy and security of geographic routing in highly dynamic UAV network,in this paper,we propose a new predictive geographic(PGeo)routing strategy with location verification.First,a detection mechanism is adopted to recognize malicious UAVs falsifying their location.Then,an accurate average service time of a packet in the medium access control(MAC)layer is derived to assist location prediction.The proposed delay model can provide a theoretical basis for future work,and our simulation results reveal that PGeo outstrips the existing geographic routing protocols in terms of packet delivery ratio in the presence of location spoofing behavior. 展开更多
关键词 Unmanned aerial vehicle Secure communication Geographic routing Location spoofing Delay estimation Location prediction Location verification
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阅读训练一
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《初中生辅导》 2025年第26期56-57,70,71,共4页
一、阅读理解主题:人与自我——生活与学习建议用时:7分钟The Wilsons decided to go overseas for vacation,They had a family meeting to plan the vacation."First,"Mr Wilson said,"we should decide where we are ... 一、阅读理解主题:人与自我——生活与学习建议用时:7分钟The Wilsons decided to go overseas for vacation,They had a family meeting to plan the vacation."First,"Mr Wilson said,"we should decide where we are going.""I don't agree,"Mrs Wilson said."I think we should decide when we are going first,We don't want to go to places when they are cold." 展开更多
关键词 planning DECISION WEATHER VACATION LOCATION time FAMILY MEETING
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Shopping at a Supermarket or a Traditional Market?
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《空中英语教室(初级版.大家说英语)》 2025年第6期40-42,55,共4页
Many people like to shop at a supermarket.Supermarkets are very convenient.They are open long hours,every day of the week.Everything is easy to find in a supermarket.It's always in the same place.Supermarkets ofte... Many people like to shop at a supermarket.Supermarkets are very convenient.They are open long hours,every day of the week.Everything is easy to find in a supermarket.It's always in the same place.Supermarkets often have sales.These can help you save money. 展开更多
关键词 SUPERMARKET hours CONVENIENCE location money saving WEEKLY SALES
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Dynamic geographies and locational factors of techno-environmentally heterogeneous data centers in Chinese cities,2006-2021
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作者 XU Jili LIU Xiangjie +1 位作者 HUANG Guan YE Yuyao 《Journal of Geographical Sciences》 2025年第9期1845-1862,共18页
Data centers operate as physical digital infrastructure for generating,storing,computing,transmitting,and utilizing massive data and information,constituting the backbone of the flourishing digital economy across the ... Data centers operate as physical digital infrastructure for generating,storing,computing,transmitting,and utilizing massive data and information,constituting the backbone of the flourishing digital economy across the world.Given the lack of a consistent analysis for studying the locational factors of data centers and empirical deficiencies in longitudinal investigations on spatial dynamics of heterogeneous data centers,this paper develops a comprehensive analytical framework to examine the dynamic geographies and locational factors of techno-environmentally heterogeneous data centers across Chinese cities in the period of 2006–2021.First,we develop a“supply-demand-environment trinity”analytical framework as well as an accompanying evaluation indicator system with Chinese characteristics.Second,the dynamic geographies of data centers in Chinese cities over the last decades are characterized as spatial polarization in economically leading urban agglomerations alongside persistent interregional gaps across eastern,central,and western regions.Data centers present dual spatial expansion trajectories featuring outward radiation from eastern core urban agglomerations to adjacent peripheries and leapfrog diffusion to strategic central and western digital infrastructural hubs.Third,it is empirically verified that data center construction in Chinese cities over the last decades has been jointly influenced by supply-,demand-,and environment-side locational factors,echoing the efficacy of the trinity analytical framework.Overall,our findings demonstrate the temporal variance,contextual contingency,and attribute-based differentiation of locational factors underlying techno-environmentally heterogeneous data centers in Chinese cities. 展开更多
关键词 data center digital infrastructure digital economy locational factor China
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A Bond Across the Seas:Cebu and Guangxi’s Growing Friendship
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《China Report ASEAN》 2025年第9期63-63,共1页
Cebu Province,a key hub in the Philippine archipelago,is known for its strategic location,abundant natural resources,and rich cultural heritage.Far across the sea in southern China,Guangxi Zhuang Autonomous Region shi... Cebu Province,a key hub in the Philippine archipelago,is known for its strategic location,abundant natural resources,and rich cultural heritage.Far across the sea in southern China,Guangxi Zhuang Autonomous Region shines with picturesque landscapes,vibrant ethnic cultures,and dynamic growth.Separated by vast waters yet linked through the China-ASEAN Expo(CAEXPO)in Nanning,the two regions have forged a strong bond of friendship. 展开更多
关键词 strong bond friendship strategic location SEAS FRIENDSHIP philippine archipelago cebu philippine archipelagois BOND
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Analysis of factors infl uencing microseismic detection and location in shale gas extraction areas of western Hubei
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作者 Hao Wan-peng Zhang Li-fen +3 位作者 Zhao Yan-nan Zheng Rong-ying Qin Wei-bing and Li Jing-gang 《Applied Geophysics》 2025年第2期523-534,561,共13页
The study area is rich in shale gas resources and has reached the stage of comprehensive development. Shale gas extraction poses risks such as induced seismicity and well closure, compounded by the limited availabilit... The study area is rich in shale gas resources and has reached the stage of comprehensive development. Shale gas extraction poses risks such as induced seismicity and well closure, compounded by the limited availability of fi xed seismic monitoring stations nearby. To address these challenges, a dense observation array was developed within the study area to monitor and analyze microseismic activity during hydraulic fracturing. Microseismic events generated by hydraulic fracturing typically exhibit low amplitude and signal-to-noise ratio, rendering traditional manual analysis methods impractical. To overcome these limitations, an innovative artifi cial intelligence method combining picking-association-location (PAL) and match-expand- shift-stack (MESS) techniques (PALM) has been utilized for automated seismic detection. Numerous factors influence the accuracy of microseismic detection and localization. To evaluate these factors, the effects of various velocity structure models, instrument types, and station distributions on seismic location were analyzed and compared. The results indicate that the PALM method significantly mitigates the influence of velocity structure models on seismic location accuracy. Additionally, the use of broadband seismic instruments and a uniform station distribution enhances the precision of seismic location results. Furthermore, by integrating data from diff erent types of observation instruments, a comprehensive seismic catalog for the study area was established. These fi ndings not only enhance seismic location accuracy but also provide valuable guidance for optimizing regional seismic monitoring network design and improving seismic risk assessment. 展开更多
关键词 earthquake location velocity structure model station distribution PALM shale gas
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Performance evaluation of the waveform stacking-based microseismic location method in the southern Sichuan Basin of China
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作者 Lei Li Jiacheng Zhang +4 位作者 Yuyang Tan Ling Peng Junlun Li Jincheng Xu Jianxin Liu 《Earthquake Science》 2025年第5期427-440,共14页
Seismic source locations can characterize the spatial and temporal distributions of seismic sources,and can provide important basic data for earthquake disaster monitoring,fault activity characterization,and fracture ... Seismic source locations can characterize the spatial and temporal distributions of seismic sources,and can provide important basic data for earthquake disaster monitoring,fault activity characterization,and fracture growth interpretation.Waveform stacking-based location methods invert the source locations by focusing the source energy with multichannel waveforms,and these methods exhibit a high level of automation and noise-resistance.Taking the cross-correlation stacking(CCS)method as an example,this work attempts to study the influential factors of waveform stacking-based methods,and introduces a comprehensive performance evaluation scheme based on multiple parameters and indicators.The waveform data are from field monitoring of induced microseismicity in the Changning region(southern Sichuan Basin of China).Synthetic and field data tests reveal the impacts of three categories of factors on waveform stacking-based location:velocity model,monitoring array,and waveform complexity.The location performance is evaluated and further improved in terms of the source imaging resolution and location error.Denser array monitoring contributes to better constraining source depth and location reliability,but the combined impact of multiple factors,such as velocity model uncertainty and multiple seismic phases,increases the complexity of locating field microseismic events.Finally,the aspects of location uncertainty,phase detection,and artificial intelligencebased location are discussed. 展开更多
关键词 seismic location waveform stacking induced microseismicity performance evaluation cross-correlation stacking
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Travel-time corrections for stations in the Guangdong seismic network and their impact on earthquake location accuracy
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作者 Ming Liang Xuan Yang +3 位作者 Ce Jiang Ping Tian Qingxi Lin Xijiao Jiang 《Earthquake Research Advances》 2025年第3期56-67,共12页
The travel-time corrections for the primary seismic phases of 72 stations in the Guangdong seismic network,relative to the 1D South China travel-time model,were determined using joint hypocentral determination(JHD)and... The travel-time corrections for the primary seismic phases of 72 stations in the Guangdong seismic network,relative to the 1D South China travel-time model,were determined using joint hypocentral determination(JHD)and statistical analysis methods.The travel-time corrections for the Pg phase of 72 stations range between-0.25 s and 0.14 s,while the corrections for the Sg phase range between 0.27 s and 0.35 s,and those for the Pn phase are between-0.86 s and 0.07 s.The spatial distribution of travel-time corrections for Pg,Sg,and Pn phases of 72 stations correlates well with the geological structure in this region.This indicates that the travel-time corrections for Pg and Sg phases are mainly caused by the discrepancy between the actual crustal velocity structure beneath the stations and the 1D South China travel-time model.These corrections empirically compensate for systematic travel-time errors arising from such discrepancies.The primary factor contributing to the travel-time corrections for the Pn phase is the Moho undulations or tilt.These corrections are intended to compensate for systematic errors in travel time caused by variations in the actual Moho.By integrating the obtained travel-time corrections into the HYPO-SAT location algorithm,test results showed an obvious improvement in location accuracy and origin time precision for explosion events.The variation of horizontal distance between repeating earthquake pairs has also improved,with 86%of the repeating earthquake pair spacing being more accurately estimated after correction.This suggests the crucial significance of travel-time correction in earthquake location,and the consideration of travel-time correction exerts a notable impact on enhancing earthquake location accuracy. 展开更多
关键词 Travel-time correction Joint hypocentral determination Statistical analysis Hyposat Location accuracy
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