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Monitoring Study of Long-Term Land Subsidence during Subway Operation in High-Density Urban Areas Based on DInSAR-GPS-GIS Technology and Numerical Simulation
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作者 Yu Song Xuejun Chen +4 位作者 Baoping Zou Jundong Mu Rusheng Hu Siqi Cheng Shengli Zhao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第2期1021-1039,共19页
During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil d... During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil during tunnel construction,dense buildings and structures in the vicinity of the tunnel,and changes in water level in the stratum where the tunnel is located.The monitoring of long-term land subsidence during subway operation in high-density urban areas differs from that in low-density urban construction areas.The former is the gathering point of the entire urban population.There are many complex buildings around the project,busy road traffic,high pedestrian flow,and less vegetation cover.Several existing items requiremonitoring.However,monitoring distance is long,and providing early warning is difficult.This study uses the 2.8 km operation line between Wulin Square station and Ding’an Road station of Hangzhou Subway Line 1 as an example to propose the integrated method of DInSAR-GPS-GIS technology and the key algorithm for long-term land subsidence deformation.Then,it selects multiscene image data to analyze long-termland subsidence of high-density urban areas during subway operation.Results show that long-term land subsidence caused by the operation of Wulin Square station to Ding’an Road station of Hangzhou Subway Line 1 is small,with maximumsubsidence of 30.64 mm,and minimumsubsidence of 11.45 mm,and average subsidence ranging from 19.27 to 21.33 mm.And FLAC3D software was used to verify the monitoring situation,using the geological conditions of the soil in the study area and the tunnel profile to simulate the settlement under vehicle load,and the simulation results tended to be consistent with the monitoring situation. 展开更多
关键词 Long-term land subsidence subway operation DInSAR-GPS-GIS technology high-density urban areas urban subway numerical simulation
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Recommendations for Large-scale Farmland Operation in Hilly Areas Based on Long Tail Theory
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作者 Changsheng QIU Dingxiang LIU 《Asian Agricultural Research》 2014年第8期53-56,共4页
At the background of urban and rural integration,this paper analyzed and discussed factors restricting large-scale farmland operation in China's hilly areas from the qualitative perspective. It recognized large-sc... At the background of urban and rural integration,this paper analyzed and discussed factors restricting large-scale farmland operation in China's hilly areas from the qualitative perspective. It recognized large-scale farmland operation on the basis of the long tail theory. Finally,it came up with recommendations for developing large-scale farmland operation in hilly areas. 展开更多
关键词 URBAN and RURAL INTEGRATION HILLY areas Large-scal
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SiC trench MOSFET with dual shield gate and optimized JFET layer for improved dynamic performance and safe operating area capability
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作者 张金平 陈伟 +1 位作者 陈子珣 张波 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期627-634,共8页
A novel silicon carbide(SiC) trench metal–oxide–semiconductor field-effect transistor(MOSFET) with a dual shield gate(DSG) and optimized junction field-effect transistor(JFET) layer(ODSG-TMOS) is proposed. The combi... A novel silicon carbide(SiC) trench metal–oxide–semiconductor field-effect transistor(MOSFET) with a dual shield gate(DSG) and optimized junction field-effect transistor(JFET) layer(ODSG-TMOS) is proposed. The combination of the DSG and optimized JFET layer not only significantly improves the device’s dynamic performance but also greatly enhances the safe operating area(SOA). Numerical analysis is carried out with Silvaco TCAD to study the performance of the proposed structure. Simulation results show that comparing with the conventional asymmetric trench MOSFET(Con-ATMOS), the specific on-resistance(Ron,sp) is significantly reduced at almost the same avalanche breakdown voltage(BVav). Moreover, the DSG structure brings about much smaller reverse transfer capacitance(Crss) and input capacitance(Ciss), which helps to reduce the gate–drain charge(Qgd) and gate charge(Qg). Therefore, the high frequency figure of merit(HFFOM) of Ron,sp·Qgdand Ron,sp· Qgfor the proposed ODSG-TMOS are improved by 83.5% and 76.4%, respectively.The switching power loss of the proposed ODSG-TMOS is 77.0% lower than that of the Con-ATMOS. In addition, the SOA of the proposed device is also enhanced. The saturation drain current(Id,sat) at a gate voltage(Vgs) of 15 V for the ODSGTMOS is reduced by 17.2% owing to the JFET effect provided by the lower shield gate(SG) at a large drain voltage. With the reduced Id,sat, the short-circuit withstand time is improved by 87.5% compared with the Con-ATMOS. The large-current turn-off capability is also improved, which is important for the widely used inductive load applications. 展开更多
关键词 SiC trench MOSFET switching power loss figure of merit safe operating area
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Moderate scale and realization potential of new citrus-planting business entities in hilly and mountainous areas in China
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作者 ZHANG Xuan-yun ZHANG Shi-chao +3 位作者 LIU Jing-yu RAN Na ZHANG Xiang NING Qi-wen 《Journal of Mountain Science》 SCIE CSCD 2023年第8期2315-2343,共29页
The natural and economic conditions of agricultural resources vary greatly in China,especially in hilly and mountainous areas.The phenomenon of land fragmentation has become increasingly prominent,so that large-scale ... The natural and economic conditions of agricultural resources vary greatly in China,especially in hilly and mountainous areas.The phenomenon of land fragmentation has become increasingly prominent,so that large-scale operations cannot be fully achieved in a short period of time,and the centralized and continuous scale of operations cannot be realized in China.In addition,with increasingly strict farmland protection and agricultural land use control systems,the issues of nongrain production and nonagricultural cultivated land use have become increasingly restricted.Thus,it is quite necessary to determine the appropriate scale of operations and the means to achieve moderately scaled operations for the new business entities.On the basis of microsurvey data for 108 new citrus-planting business entities in the modern agricultural park in the Chongqing's Jiangjin District,an area with long citrus-planting history,we measured the moderate scale of new citrus-planting business entities to maximize profit using a translog growth model.According to the projection pursuit model,we evaluated the suitability conditions of citrus planting in garden land,woodland,grassland,and general cultivated land in the study area.We then explored the potential for new moderate-scale business entities within different farming radii.The results showed that large-scale planting conditions of citrus in garden land,forest land,grassland,and general cultivated land in the study area were suitable,and the proportion of high-suitable and mediumsuitable land was 73.42%.Under the existing social and economic conditions,the moderate scale of new citrus-planting business entities in the study area was 1.8–2.7 hm^(2).In particular,its rankings from large to small were agricultural enterprises(17.19–25.78 hm^(2)),farmer cooperatives(16.88–25.33 hm^(2)),big growers and breeders(6.39–9.59 hm^(2)),and family farms(5.02–7.53 hm^(2)).In the sample of 108 households,only 47.22%of the entities achieved moderate-scale operation,of which 25%of the entities achieved a scale greater than moderate operation.However,52.78%of the entities achieved a scale of less than moderate operation.These entities would have to transfer the surrounding adjacent garden land,forest land,grassland,or general cultivated land to achieve largescale land management.The land area of the adjacent gardens in a 1000 m farming radius could meet the moderate-scale operation demand of the vast majority of new business entities.For the vast majority of new business entities,the land area of the adjacent woodland,grassland,and general cultivated land could supplement the garden land to achieve moderate-scale operation in a 500 m farming radius.If the land area with moderate suitability and high suitability is prioritized,the land area in the adjacent gardens in the 1000 m farming radius could meet the moderate-scale operation demand for the vast majority of new business entities.Within the 500 m farming radius,the vast majority of new business entities have achieved moderate-scale operations if the land area adjacent to forest land,grassland,and general arable land was supplemented by gardens;however,a few entities could not achieve moderate-scale operations.From the village perspective,gardens were prioritized.Sixteen villages had planting areas and planting suitability that exceeded the average level of the study area,accounting for 23.53%.If combined with the reserve potential of the garden land,eight villages could improve their potential,accounting for 11.76%.Therefore,the conditions of large-scale citrus planting in the study area should be further improved,and the scale expansion of new citrus-planting business entities should receive additional scientific guidance. 展开更多
关键词 Land management Hilly and mountainous areas Agricultural business entities Moderate operation scale Agricultural land resources Realizing potential
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Application of the Regulations on Drawing of a Safe Firing Area Map in Weather Modification Operation 被引量:1
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作者 Wang Xiaoli Wang Tianru +3 位作者 Zhang Na Xu Tai’an Lu Dan Zhang Xiuzhen 《Meteorological and Environmental Research》 CAS 2017年第1期31-32,共2页
Technology for safe firing area maps was introduced firstly,and then potential danger after the launching of shells by an antiaircraft gun and a rocket was analyzed.Finally,problems in the process of applying the regu... Technology for safe firing area maps was introduced firstly,and then potential danger after the launching of shells by an antiaircraft gun and a rocket was analyzed.Finally,problems in the process of applying the regulations and their solutions were discussed.The application of safe firing area maps can provide technical support for the efficient development of weather modification operation. 展开更多
关键词 WEATHER modification operation SAFE FIRING area maps REGULATIONS APPLICATION China
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Combination Operation for Neutral Point of 35 kV Power Grids in Mountainous Area 被引量:2
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作者 YUAN Tao SIMA Wen-xia +1 位作者 RAN Rui ZHU Wei 《高电压技术》 EI CAS CSCD 北大核心 2008年第12期2626-2630,共5页
Based on a lot of measurement and analysis,this paper find that the unbalanced nature of 35 kV grids due to unsymmetrical capacitance values gives difficulty in neutral point operation in mountainous area.Improving co... Based on a lot of measurement and analysis,this paper find that the unbalanced nature of 35 kV grids due to unsymmetrical capacitance values gives difficulty in neutral point operation in mountainous area.Improving compensation of Petersen coil can rectify imbalance of voltage but bring up new problem that Petersen coil can not extinguish grounding arc effectively in fault.To put down contradiction mentioned above,this paper proposes a combination operation for neutral point of 35 kV grids as neutral point insulated in routine operation and grounding through Petersen coil in fault,then EMTP simulation is carried out.Simulation indicates that new neutral operation method can improve lightning withstand level and decrease trip-out rate of grids. 展开更多
关键词 山区 补偿电网 消弧线圈 投切运行 暂态分析
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Study on Winter Operation Process of the Surface Flow Constructed Wetland in Tianjin Area
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作者 Xiaodan Qin Yichao Sun +5 位作者 Li Li Xiaolong Shao Dan Yu Qiongqiong Liu Honglei Liu Lin Han 《Meteorological and Environmental Research》 CAS 2013年第7期43-46,共4页
[Objective] The research aimed to study winter operation process of the surface flow constructed wetland in "rianjin area. [Method] In view of climate characteristics in Tianjin, by the way of running under the ice, ... [Objective] The research aimed to study winter operation process of the surface flow constructed wetland in "rianjin area. [Method] In view of climate characteristics in Tianjin, by the way of running under the ice, winter operation experiment of the surface flow constructed wetland in Tianjin was conducted, with the expectation to get some useful process parameters to run such systems in North China in winter. [ Result] Although purification effect of the sewage by surface flow constructed wetland in winter was worse than that in other seasons ( average reduction of about 20%), surface flow constructed wetland running under the ice was feasible in Tianjin area. When surface flow constructed wetland in North China ran under ice in winter, it was suggested that the outlet must be located in a low position to prevent to be completely frozen, and running water depth should not be less than 50 -60 cm. The hydraulic load could be raised on the basis of reflux, and hydraulic retention time should maintain less than 4 d to keep water-soil interface not freezing. Inlet water depth should be increased as much as possible to improve temperature in the system. V Conclusion1 The research could provide reference for promotion and application of the surface flow constructed wetland in North China. 展开更多
关键词 Surface flow constructed wetland operation process WINTER Tianjin area China
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Esophageal nasopharyngeal catheter in the wake-up anesthesia of the brain function area operations
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作者 蔡铁良 《外科研究与新技术》 2011年第3期219-220,共2页
Objective To evaluate the feasibility and safety of the self developed sound outside the ventilation device-esophageal nasopharynx catheter in brain functional areas surgery applications. Methods 13 patients involved ... Objective To evaluate the feasibility and safety of the self developed sound outside the ventilation device-esophageal nasopharynx catheter in brain functional areas surgery applications. Methods 13 patients involved functional areas of brain surgery were chosed. After induction of general anesthesia,the catheters were placed in the esophagus,then connected to anesthesia machines to an external 展开更多
关键词 Esophageal nasopharyngeal catheter in the wake-up anesthesia of the brain function area operations area
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AREA FUNCTIONS ON HARDY SPACES ASSOCIATED TO SCHRDINGER OPERATORS 被引量:2
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作者 朱月萍 《Acta Mathematica Scientia》 SCIE CSCD 2003年第4期521-530,共10页
In this paper, the author gives a characterization of atomic Hardy spaces associated to Schrodinger operators by using area functions, and hence gets the dual spaces of atomic Hardy spaces.
关键词 Square function area function Hardy spaces Schrodinger operators
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AREA INTEGRAL FUNCTIONS FOR SECTORIAL OPERATORS ON L^p SPACES 被引量:1
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作者 陈泽乾 孙牧 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期739-747,共9页
Area integral functions are introduced for sectorial operators on L^p-spaces. We establish the equivalence between the square and area integral functions for sectorial operators on L^p spaces. This follows that the re... Area integral functions are introduced for sectorial operators on L^p-spaces. We establish the equivalence between the square and area integral functions for sectorial operators on L^p spaces. This follows that the results of Cowling, Doust, McIntosh, Yagi, and Le Merdy on H^∞ functional calculus of seetorial operators on LP-spaces hold true when the square functions are replaced by the area integral functions. 展开更多
关键词 Sectorial operator H^∞ Functional calculus area integral function square function L^p space
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AREA INTEGRAL FUNCTIONS AND H∞ FUNCTIONAL CALCULUS FOR SECTORIAL OPERATORS ON HILBERT SPACES
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作者 陈泽乾 孙牧 《Acta Mathematica Scientia》 SCIE CSCD 2013年第4期989-997,共9页
Area integral functions are introduced for sectorial operators on Hilbert spaces. We establish the equivalence relationship between the square and area integral functions. This immediately extends McIntosh/Yagi's res... Area integral functions are introduced for sectorial operators on Hilbert spaces. We establish the equivalence relationship between the square and area integral functions. This immediately extends McIntosh/Yagi's results on H∞ functional calculus of sectorial operators on Hilbert spaces to the case when the square functions are replaced by the area integral functions. 展开更多
关键词 sectorial operator H∞ functional calculus area integral function squarefunction Hilbert space
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Effect of Serial PMSs on Operational Benefits of Arrival Flights
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作者 XU Can WANG Xunuo +1 位作者 TIAN Yong WANG Zhan 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2022年第S01期73-81,共9页
In order to alleviate the flight congestion in terminal areas(TMAs),it is of great significance to develop an effective method.An arrival sequencing model based on the serial point merge systems(PMSs)is constructed to... In order to alleviate the flight congestion in terminal areas(TMAs),it is of great significance to develop an effective method.An arrival sequencing model based on the serial point merge systems(PMSs)is constructed to improve the operational benefits of arrival flights.The approach of first come first service(FCFS)combined with the method of constraint position shift(CPS)is used as the sequencing strategy.Through the simulated annealing algorithm,the results show that the arrival flights sequencing through serial PMSs has significant advantages in reducing delays and increasing runway throughput especially in the case of high traffic loads.The proposed approach is conducive in promoting the implementation and application of serial PMS. 展开更多
关键词 serial point merge systems(PMSs) terminal area(TMA) arrival flights operational benefits
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On Maximal, Discrete, and Area Operators
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作者 Chunping Xie 《Journal of Mathematics and System Science》 2015年第1期26-31,共6页
In this paper, we study the boundednesses of maximal operator g., the discrete operator gd, and the area operator A on Bergman spaces.
关键词 area operator Bergman Space Discrete Maximal operator Hardy Space maximal operator
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Research on the Optimization Design of Intersections for Safe Operation of Large Trucks
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作者 Yujie Bao Pincheng Wang Yuhang Li 《Journal of Information Hiding and Privacy Protection》 2020年第3期143-154,共12页
When big trucks are running at urban road intersections,they are easy to interfere with other motor vehicles,and the turning big trucks are easy to have conflicts with non-motor vehicles and pedestrians,which will aff... When big trucks are running at urban road intersections,they are easy to interfere with other motor vehicles,and the turning big trucks are easy to have conflicts with non-motor vehicles and pedestrians,which will affect the safety of intersections.This paper first studied the intersection of trucks to the running trajectory,on this basis,through the establishment of mathematical model analysis of large truck steering conditions inside the wheel,and the influence of blind area to the driver.In the research of intersection safety design,the safety design is divided into three parts:Entrance road,internal operation and signal control.At the same time,the design method of the entrance road,the interior of the intersection and the signal control is given,which improves the safety of the truck driving at the intersection.Finally,the intersection of Jungong road and Zhoujiazui road in Yangpu district of Shanghai was selected as a case,and the optimal design of the intersection for large trucks was carried out through the investigation and analysis of actual data.The evaluation and analysis were carried out by using the multi-index matter-element model.The results show that the comprehensive safety correlation degree of the intersection is reduced to 0.42,and the safety level of is improved by one level. 展开更多
关键词 Large truck city road intersection safety design safety operation inner wheel difference blind area
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CLINICAL OBSERVATION ON ACUPOINT DIGITAL PRESSING FOR TREATING IRRITABLE SYMPTOMS AND SIGNS OF POSTOPERATION OF MYOPORTHOSIS
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作者 王晓阳 《World Journal of Acupuncture-Moxibustion》 2002年第3期48-50,共3页
Objective: To explore a new effective approach for treatment of the local irritable symptoms and signs resulted from myoporthosis operation. Methods: 263 cases of radial keratotomy outpatients were divided into contro... Objective: To explore a new effective approach for treatment of the local irritable symptoms and signs resulted from myoporthosis operation. Methods: 263 cases of radial keratotomy outpatients were divided into control group (n=49, 90 eyes) and treatment group (n=214, 412 eyes). Patients of control group were treated with 0.5% Chloramphenicol eye drops, 3 times daily, 1-2 drops/time, and with 0.5% Erythromycine eye ointment every night. In treatment group, patients were treated with acupoint and hand reflection area digital pressing method except with the same eye drops and eye ointment. Body acupoints used were Cuanzhu (BL 2), Yuyao (EX HN 4), Sizhukong (TE 23), Sibai (ST 2) and Taiyang (EX HN 5). The hand reflex areas used were Eye Area, Liver Area, Kidney Area, Spleen Area, Heart Area and Lung Area. Five days constituted a therapeutic course. Results: Following 3 courses (15 days) of treatment, the markedly effective rate and total effective rate of treatment group and control group were 74.51% and 38.89%, 94.17% and 66.67% respectively. There was a significant difference between two groups in the total effective rate (P<0.05), showing the therapeutic effect of treatment group being better than that of control group. Conclusion: Acupoint digital pressing is rather effective in treatment of myoporthosis post operation irritable symptoms and signs. 展开更多
关键词 Post operation symptoms of myoporthosis Acupoint digital pressing treatment Body acupoints and hand reflex areas
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How Does the Farmer Cooperatives Operate in Yanbian Area?
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作者 Kebin SONG Xuyou WANG +1 位作者 Xinglong YANG Shu WANG 《Asian Agricultural Research》 2013年第11期126-129,共4页
After six years of development,the number of farmer cooperatives in Yanbian area was increased from 72 in 2007 to 2600 in 2012.It has become an important part of local modern agricultural operation.Through the survey ... After six years of development,the number of farmer cooperatives in Yanbian area was increased from 72 in 2007 to 2600 in 2012.It has become an important part of local modern agricultural operation.Through the survey and research of current status of farmer cooperatives in Yanbian area,we analyze the deficiencies in capital,technology and human resources during the operating to thoroughly understand its operating status.On this basis,we put forth some recommendations for the development of farmer cooperatives in Yanbian area:implementing industrialization operation;developing long-term development strategy;seeking the support of research institutions and colleges;increasing the types of services;enhancing the value-added. 展开更多
关键词 FARMER cooperatives INDUSTRIALIZATION operation YA
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Object-Based Burned Area Mapping with Extreme Gradient Boosting Using Sentinel-2 Imagery
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作者 Dimitris Stavrakoudis Ioannis Z. Gitas 《Journal of Geographic Information System》 2023年第1期53-72,共20页
The Sentinel-2 satellites are providing an unparalleled wealth of high-resolution remotely sensed information with a short revisit cycle, which is ideal for mapping burned areas both accurately and timely. This paper ... The Sentinel-2 satellites are providing an unparalleled wealth of high-resolution remotely sensed information with a short revisit cycle, which is ideal for mapping burned areas both accurately and timely. This paper proposes an automated methodology for mapping burn scars using pairs of Sentinel-2 imagery, exploiting the state-of-the-art eXtreme Gradient Boosting (XGB) machine learning framework. A large database of 64 reference wildfire perimeters in Greece from 2016 to 2019 is used to train the classifier. An empirical methodology for appropriately sampling the training patterns from this database is formulated, which guarantees the effectiveness of the approach and its computational efficiency. A difference (pre-fire minus post-fire) spectral index is used for this purpose, upon which we appropriately identify the clear and fuzzy value ranges. To reduce the data volume, a super-pixel segmentation of the images is also employed, implemented via the QuickShift algorithm. The cross-validation results showcase the effectiveness of the proposed algorithm, with the average commission and omission errors being 9% and 2%, respectively, and the average Matthews correlation coefficient (MCC) equal to 0.93. 展开更多
关键词 operational Burned area Mapping Sentinel-2 Extreme Gradient Boosting (XGB) QuickShift Segmentation Machine Learning
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深入学习习近平“三农”工作论述精神 被引量:2
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作者 孔祥智 李愿 《农林经济管理学报》 北大核心 2024年第2期135-141,共7页
习近平“三农”工作论述是习近平新时代中国特色社会主义思想的重要部分,具有深刻的理论逻辑与实践理路。其核心在于以高度重视“三农”问题为出发点,向四个维度进行阐释分析:一是高度重视粮食安全;二是坚持农村基本经营制度;三是促进... 习近平“三农”工作论述是习近平新时代中国特色社会主义思想的重要部分,具有深刻的理论逻辑与实践理路。其核心在于以高度重视“三农”问题为出发点,向四个维度进行阐释分析:一是高度重视粮食安全;二是坚持农村基本经营制度;三是促进小农户与现代农业有机衔接;四是坚持城乡融合发展。习近平“三农”工作论述将农业现代化建设置于中国特色社会主义现代化进程,在顶层设计角度对农业、农村、农民的现实问题作出回应。认真理解与贯彻习近平“三农”工作论述,有助于理解新时代中国特色社会主义发展阶段,这对于把握新时代“三农”工作的脉搏具有重要意义。 展开更多
关键词 习近平“三农”工作论述 农业农村现代化 农村基本经营制度 城乡融合发展
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粮食主产区的新型城镇化与粮食安全——基于土地规模化经营中介效应检验 被引量:1
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作者 华坚 杨梦依 曹慧敏 《资源与产业》 2024年第1期50-60,共11页
在新时代发展背景下,新型城镇化成为粮食主产区城乡二元结构变革和农业生产方式转型的关键。论文基于2007—2021年我国13个粮食主产区的省级面板数据,从产业链视角利用熵值法测度粮食安全水平,基于新型城镇化内涵构建包含人口、经济、... 在新时代发展背景下,新型城镇化成为粮食主产区城乡二元结构变革和农业生产方式转型的关键。论文基于2007—2021年我国13个粮食主产区的省级面板数据,从产业链视角利用熵值法测度粮食安全水平,基于新型城镇化内涵构建包含人口、经济、社会、空间的多维度指标体系并测度新型城镇化水平,探究新型城镇化对粮食安全的影响,并以土地规模化经营为中介变量,分析新型城镇化及其各维度影响粮食安全的作用机制。结果表明:1)粮食主产区的新型城镇化对粮食安全有显著的促进作用,并且土地规模化经营在新型城镇化对粮食安全的作用过程中存在中介效应;2)分维度异质性分析表明,人口城镇化与空间城镇化对粮食安全产生显著的正向影响,且土地规模化经营在其中发挥部分或完全的中介效应。为此,提出积极推进新型城镇化、鼓励土地规模化经营并从人口、经济、社会、空间城镇化多个维度因地制宜调整粮食发展战略是粮食主产区发展的长远之策。 展开更多
关键词 粮食安全 新型城镇化 土地规模化经营 粮食主产区 中介效应
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肾小管及肾小球标志物在2型糖尿病患者不同肾损伤阶段诊断价值的研究
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作者 张琳 谢荣荣 +5 位作者 杨芳远 李眉 罗莎 万晓华 田玮 杨金奎 《首都医科大学学报》 CAS 北大核心 2024年第3期429-437,共9页
目的探讨肾小管及肾小球相关标志物在2型糖尿病(type 2 diabetes mellitus,T2DM)患者不同肾损伤阶段的诊断价值。方法选取于2018年4月1日至2019年10月31日入住首都医科大学附属北京同仁医院内分泌科的T2DM患者272例,完善临床生化指标及... 目的探讨肾小管及肾小球相关标志物在2型糖尿病(type 2 diabetes mellitus,T2DM)患者不同肾损伤阶段的诊断价值。方法选取于2018年4月1日至2019年10月31日入住首都医科大学附属北京同仁医院内分泌科的T2DM患者272例,完善临床生化指标及尿蛋白四项:尿微量白蛋白/肌酐(urinary albumin to creatinine ratio,ACR)、α1-微球蛋白/肌酐(urinary α1-microglobulin to creatinine ratio,UA1CR)、免疫球蛋白G/肌酐(urinary immunoglobulin G to creatinine ratio,UIGG)、转铁蛋白/肌酐(urinary transferrin to creatinine ratio,UTRF);进行眼底照相、核医学99mTc-EC检测肾有效血浆流量(effective renal plasma flow,ERPF)和99mTc-DTPA检测肾小球滤过率(glomerular filtration rate,GFR)。根据ACR和眼底检查结果分为4组:正常蛋白尿无糖尿病视网膜病变(diabetic retinopathy,DR)132例,即对照组(ACR≤30 mg/g);正常蛋白尿合并DR 32例,为糖尿病肾病(diabetic kidney disease,DKD)前期组;微量蛋白尿组78例(30<ACR≤300 mg/g)和大量蛋白尿组30例(ACR>300 mg/g)。比较四组间尿蛋白四项和ERPF、GFR的水平,通过受试者工作特征(receiver operating characteristic,ROC)曲线评价上述各指标在不同肾损伤阶段的诊断价值。结果尿蛋白四项和ERPF、GFR的水平在不同组间差异有统计学意义(P<0.05)。在尿蛋白正常组中,DR组中肾小管功能标志物UA1CR较对照组明显升高(P<0.01);肾小球功能标志物ACR、UTRF和GFR在两组间差异无统计学意义(P>0.05),DR组UIGG较对照组升高(P<0.01)。在微量蛋白尿组和大量蛋白尿组,尿蛋白四项随肾损伤程度增加而增加,而ERPF和GFR随肾损伤程度增加而降低。ROC曲线分析显示,在尿蛋白排出正常的T2DM患者中合并DR组中肾小管功能标志物UA1CR和ERPF的曲线下面积(area under the curve,AUC)分别为68.2%(P<0.01)和60.5%(P<0.05),而肾小球功能标志物ACR和GFR的AUC均小于60%,差异无统计学意义(P>0.05)。尿蛋白四项及GFR在微量和大量蛋白尿组的AUC均大于60%(P<0.05),ERPF在大量蛋白尿组AUC为67.2%(P<0.05)。结论T2DM极早期微血管改变即ACR正常仅有DR时,肾小管标志物UA1CR先于肾小球标志物ACR和GFR发生变化。肾损伤早期,肾小管标志物诊断效能优于肾小球;肾损伤后期,肾小球标志物诊断效能优于肾小管。提示DKD肾小管功能的改变可能早于肾小球。 展开更多
关键词 糖尿病肾病 肾小管标志物 Α1-微球蛋白 肾有效血浆流量 ROC曲线下面积
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