As China＇s energy strategy moving westward, the surface movement and deformation characteristics due to high-intensive coal mining in the windy and sandy region become a research hotspot. Surface movement observation...As China＇s energy strategy moving westward, the surface movement and deformation characteristics due to high-intensive coal mining in the windy and sandy region become a research hotspot. Surface movement observation stations were established to monitor movement and deformation in one super-large working face. Based on field measurements, the surface movement and deformation characteristics were obtained, including angle parameters, subsidence prediction parameters, etc. Besides, the angle and subsidence prediction parameters in similar mining areas are summarized; the mechanism of surface movement and deformation was analyzed with the combination of key stratum theory, mining and geological conditions. The research also indicates that compared with conventional working faces, uniform subsidence area of the subsidence trough in the windy and sandy region is larger, the trough margins are relative steep and deformation values present convergence at the margins, the extent of the trough shrink towards the goaf and the influence time of mining activities lasts shorter; the overlying rock movement and breaking characteristics presents regional particularity in the study area, while the single key stratum, thin bedrock and thick sand that can rapidly propagate movement and deformation are the deep factors, contributing to it.展开更多
An observational analysis of the structures and characteristics of a windy atmospheric boundary layer during a cold air outbreak in the South China Sea region is reported in this paper. It is found that the main struc...An observational analysis of the structures and characteristics of a windy atmospheric boundary layer during a cold air outbreak in the South China Sea region is reported in this paper. It is found that the main structures and characteristics are the same as during strong wind episodes with cold air outbreaks on land. The high frequency turbulent fluctuations （period 〈 1 min） are nearly random and isotropic with weak coherency, but the gusty wind disturbances （1 rain〈period 〈 10 min） are anisotropic with rather strong coherency. However, in the windy atmospheric boundary layer at sea, compared with that over land, there are some pronounced differences： （1） the average horizontal speed is almost independent of height, and the vertical velocity is positive in the lower marine atmospheric boundary layer; （2） the vertical flux of horizontal momentum is nearly independent of height in the low layer indicating the existence of a constant flux layer, unlike during strong wind over the land surface; （3） the kinetic energy and friction velocity of turbulent fluctuations are larger than those of gusty disturbances; （4） due to the independence of horizontal speed to height, the horizontal speed itself （not its vertical gradient used over the land surface） can be used as the key parameter to parameterize the turbulent and gusty characteristics with high accuracy.展开更多
[Objectives]The paper was to investigate the distribution characteristics of soil total nitrogen in low-efficiency forest land in the northern windy desert area of Jingbian County.[Methods]The distribution of soil tot...[Objectives]The paper was to investigate the distribution characteristics of soil total nitrogen in low-efficiency forest land in the northern windy desert area of Jingbian County.[Methods]The distribution of soil total nitrogen in the 0-40 cm soil layer of 5 towns in the northern windy desert area of Jingbian County was studied through field sampling and laboratory detection.[Results]The average soil total nitrogen contents of Hongdunjie Town,Haizetan Town,Huanghaojie Town,Ningtiaoliang Town,Dongkeng Town and windy desert area in the 0-20 cm soil layer were 0.259,0.224,0.242,0.248,0.431 and 0.275 g/kg,respectively.The soil total nitrogen content in Dongkeng Town was higher than those in other towns,while there was little difference among other regions.The average total nitrogen contents in the 20-40 cm soil layer were 0.239,0.285,0.113,0.262,0.349 and 0.241 g/kg,respectively.The soil total nitrogen content in Huanghaojie Town was slightly lower than those in other towns,while that in Dongkeng town was higher.The variation coefficient of soil total nitrogen content in the survey area was greater than 30%,and there was great difference in spatial distribution.With the increase of soil depth,there was little change in soil total nitrogen content,namely the soil total nitrogen contents in 5 towns and windy desert area were not statistically different in the 0-40 cm soil layer.According to the nutrient grading standard of the second national soil survey,the soil total nitrogen content in the survey area was in the deficiency grade.[Conclusions]The research will provide a scientific guidance for the healthy and sustainable development of vegetation in arid regions.展开更多
With the nature of the high wind and sand in western China,the Chinese wolfberry recognition shows a strong relationship with the sandy noise and needs a high-accuracy algorithm.To address this issue,this study aimed ...With the nature of the high wind and sand in western China,the Chinese wolfberry recognition shows a strong relationship with the sandy noise and needs a high-accuracy algorithm.To address this issue,this study aimed to develop an algorithm for accurately detecting and recognizing wolfberries.YOLOv8,an algorithm promoted by Ultralytics,supports image classification,object detection,and instance segmentation tasks.To enhance the performance of the original YOLOv8 model,a novel YOLOv8 algorithm incorporating FasterNet,RepBiFPN,and Lightweight Asymmetric Dual-Head was proposed.Firstly,thousands of Chinese wolfberry images were collected from the Ningxia Academy of Agriculture and Forestry Science,China,and random noises were added to simulate the wind and sand conditions typical of spring.Secondly,leveraging the advantages of YOLOv8n,such as its high speed and accuracy,this research innovatively integrated the FasterNet block into the C2f module of YOLOv8 to improve the effective handling of data uncertainty and noise.Additionally,an innovative RepViT+BiFPN,a new detective head,and a Lightweight Asymmetric Dual-Head were introduced to improve the training efficiency of the YOLOv8 network.Finally,to evaluate the effectiveness of improved YOLOv8 for the recognition of wolfberry,the dataset of wolfberry images was divided into a training set,a validation set,and a testing set to assess the performances of different models.Experiment results demonstrate that the YOLOv8-FasterNet+LADH+RepBiFPN model outperforms other models in terms of mAP@0.50-0.95,achieving a 4.5%improvement on the validation set compared to the original YOLOv8n.This research addresses the high-speed and accurate recognition of the Chinese wolfberry under strong winds and sand noise through algorithmic improvements and integration,which can facilitate the automation and intelligence of Chinese wolfberry harvesting and contribute to the advancement of agricultural mechanization.展开更多
A new sound source localization method with sound speed compensation is proposed to reduce the wind influence on the performance of conventional TDOA （Time Difference of Arrival） algorithms. First, the sound speed i...A new sound source localization method with sound speed compensation is proposed to reduce the wind influence on the performance of conventional TDOA （Time Difference of Arrival） algorithms. First, the sound speed is described as a set of functions of the unknown source location, to approximate the acoustic velocity field distribution in the wind field. Then, they are introduced into the TDOA algorithm, to construct nonlinear equations. Finally, the particle swarm optimization algorithm is used to estimate the source location. The simulation results show that the proposed algorithm can significantly improve the localization accuracy for different wind velocities, source locations and test area sizes. The experimental results show that the proposed method can reduce localization errors to about 40% of the original error in a four nodes localization system.展开更多
If we restrict the postman to traversing each edge at most twice in the windypostman problem (WPP), we will get a new problem: 2WPP. An approximation algorithmhas been posed by M. Guan for the WPP. In the present pape...If we restrict the postman to traversing each edge at most twice in the windypostman problem (WPP), we will get a new problem: 2WPP. An approximation algorithmhas been posed by M. Guan for the WPP. In the present paper, we improve the estimatederror given by M. Guan and show that we can estimate the error for the 2WPP by findinga minimum cost circulation. We also pose a new sufficient condition for the equivalencebetween WPP and 2WPP, which can be checked in polynomial time steps.展开更多
Accurately predicting photovoltaic(PV)power generation is essential for effective power system scheduling.However,increased incidences of sandy weather in recent years pose significant challenges for PV power plants i...Accurately predicting photovoltaic(PV)power generation is essential for effective power system scheduling.However,increased incidences of sandy weather in recent years pose significant challenges for PV power plants in desert regions.This study addresses the inaccuracies in PV power forecasting under windy-sandy conditions by conducting wind tunnel experiments to evaluate the impact of varying wind speeds and PV panel tilt angles on power generation.Polynomial equations are developed through polynomial surface fitting to establish a relationship between the power loss rate,sand-blowing wind speed,and panel tilt angle.Latin hypercube sampling is used to extend the fitted surface scenarios,simulating real-world variations in PV power generation to enhance the accuracy and applicability of the model.In addition,the model incorporates three uncertainties related to wind direction,module aging,and airflow effects on PV arrays.A case study utilizing data from a PV power plant employs the Pseudo-similar day selection method,enabling a comparative analysis of the predicted outcomes with traditional methodologies.This comparison demonstrates the accuracy and effectiveness of the proposed method for improving PV power prediction under challenging conditions.展开更多
基金Financial supports for this work, are provided by the National Natural Science Foundation of China （NSFC） ＆ Shenhua Group Corporation Limited key support project of the coal joint fund （U1361203） and NSFC under Grant No. 41501562. Thanks are also due to some participants for rendering assistant cooperation during studies.
文摘As China＇s energy strategy moving westward, the surface movement and deformation characteristics due to high-intensive coal mining in the windy and sandy region become a research hotspot. Surface movement observation stations were established to monitor movement and deformation in one super-large working face. Based on field measurements, the surface movement and deformation characteristics were obtained, including angle parameters, subsidence prediction parameters, etc. Besides, the angle and subsidence prediction parameters in similar mining areas are summarized; the mechanism of surface movement and deformation was analyzed with the combination of key stratum theory, mining and geological conditions. The research also indicates that compared with conventional working faces, uniform subsidence area of the subsidence trough in the windy and sandy region is larger, the trough margins are relative steep and deformation values present convergence at the margins, the extent of the trough shrink towards the goaf and the influence time of mining activities lasts shorter; the overlying rock movement and breaking characteristics presents regional particularity in the study area, while the single key stratum, thin bedrock and thick sand that can rapidly propagate movement and deformation are the deep factors, contributing to it.
基金supported by the National Nature Science Foundation of China (NSFC, Grant Nos. 40830103 and 41375018)a National Program on Key Basic Research project (973 Program) (Grant No. 2010CB951804)+2 种基金the plan of the State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences (Grant No. LAPC-KF-2013-11)China Special Fund for Meteorological Research in the Public Interest (Grant No. GYHY200906008)the program of the Chinese Academy of Sciences (Grant No. XDA10010403)
文摘An observational analysis of the structures and characteristics of a windy atmospheric boundary layer during a cold air outbreak in the South China Sea region is reported in this paper. It is found that the main structures and characteristics are the same as during strong wind episodes with cold air outbreaks on land. The high frequency turbulent fluctuations （period 〈 1 min） are nearly random and isotropic with weak coherency, but the gusty wind disturbances （1 rain〈period 〈 10 min） are anisotropic with rather strong coherency. However, in the windy atmospheric boundary layer at sea, compared with that over land, there are some pronounced differences： （1） the average horizontal speed is almost independent of height, and the vertical velocity is positive in the lower marine atmospheric boundary layer; （2） the vertical flux of horizontal momentum is nearly independent of height in the low layer indicating the existence of a constant flux layer, unlike during strong wind over the land surface; （3） the kinetic energy and friction velocity of turbulent fluctuations are larger than those of gusty disturbances; （4） due to the independence of horizontal speed to height, the horizontal speed itself （not its vertical gradient used over the land surface） can be used as the key parameter to parameterize the turbulent and gusty characteristics with high accuracy.
基金Supported by Internal Scientific Research Project of Shaanxi Provincial Land Engineering Construction Group Co.,Ltd.(DJNY2022-21)Shaanxi Provincial Youth Talent Promotion Program(NYKJ202228)+1 种基金Technology Innovation Center for Land Engineering and Human Settlements,Shaanxi Provincial Land Engineering Construction Group Co.,Ltd.and Xi an Jiaotong University(2021WHZ0094)Shaanxi Provincial Enterprise Innovation Striving for the First Young Talents Support Program Project(2021-1-2).
文摘[Objectives]The paper was to investigate the distribution characteristics of soil total nitrogen in low-efficiency forest land in the northern windy desert area of Jingbian County.[Methods]The distribution of soil total nitrogen in the 0-40 cm soil layer of 5 towns in the northern windy desert area of Jingbian County was studied through field sampling and laboratory detection.[Results]The average soil total nitrogen contents of Hongdunjie Town,Haizetan Town,Huanghaojie Town,Ningtiaoliang Town,Dongkeng Town and windy desert area in the 0-20 cm soil layer were 0.259,0.224,0.242,0.248,0.431 and 0.275 g/kg,respectively.The soil total nitrogen content in Dongkeng Town was higher than those in other towns,while there was little difference among other regions.The average total nitrogen contents in the 20-40 cm soil layer were 0.239,0.285,0.113,0.262,0.349 and 0.241 g/kg,respectively.The soil total nitrogen content in Huanghaojie Town was slightly lower than those in other towns,while that in Dongkeng town was higher.The variation coefficient of soil total nitrogen content in the survey area was greater than 30%,and there was great difference in spatial distribution.With the increase of soil depth,there was little change in soil total nitrogen content,namely the soil total nitrogen contents in 5 towns and windy desert area were not statistically different in the 0-40 cm soil layer.According to the nutrient grading standard of the second national soil survey,the soil total nitrogen content in the survey area was in the deficiency grade.[Conclusions]The research will provide a scientific guidance for the healthy and sustainable development of vegetation in arid regions.
基金supported by the National Natural Science Foundation of China(Grant No.32201681)the Ningxia Hui Autonomous Region Science and Technology Program(Grant 2021BEF02001)+2 种基金the Fruit,Vegetable,and Tea Harvesting Machinery Innovation Project of the Chinese Academy of Agricultural Sciencesthe Jiangsu Agriculture Science and Technology Innovation Fund(Grant JASTIF,CX(23)3036)the Changzhou Sci&Tech Program(Grant CJ20241131).
文摘With the nature of the high wind and sand in western China,the Chinese wolfberry recognition shows a strong relationship with the sandy noise and needs a high-accuracy algorithm.To address this issue,this study aimed to develop an algorithm for accurately detecting and recognizing wolfberries.YOLOv8,an algorithm promoted by Ultralytics,supports image classification,object detection,and instance segmentation tasks.To enhance the performance of the original YOLOv8 model,a novel YOLOv8 algorithm incorporating FasterNet,RepBiFPN,and Lightweight Asymmetric Dual-Head was proposed.Firstly,thousands of Chinese wolfberry images were collected from the Ningxia Academy of Agriculture and Forestry Science,China,and random noises were added to simulate the wind and sand conditions typical of spring.Secondly,leveraging the advantages of YOLOv8n,such as its high speed and accuracy,this research innovatively integrated the FasterNet block into the C2f module of YOLOv8 to improve the effective handling of data uncertainty and noise.Additionally,an innovative RepViT+BiFPN,a new detective head,and a Lightweight Asymmetric Dual-Head were introduced to improve the training efficiency of the YOLOv8 network.Finally,to evaluate the effectiveness of improved YOLOv8 for the recognition of wolfberry,the dataset of wolfberry images was divided into a training set,a validation set,and a testing set to assess the performances of different models.Experiment results demonstrate that the YOLOv8-FasterNet+LADH+RepBiFPN model outperforms other models in terms of mAP@0.50-0.95,achieving a 4.5%improvement on the validation set compared to the original YOLOv8n.This research addresses the high-speed and accurate recognition of the Chinese wolfberry under strong winds and sand noise through algorithmic improvements and integration,which can facilitate the automation and intelligence of Chinese wolfberry harvesting and contribute to the advancement of agricultural mechanization.
基金supported by the National Natural Science Fundation of China(61501374)Underwater Information and Control Key Laboratory Fundation(9140C230310150C23102)
文摘A new sound source localization method with sound speed compensation is proposed to reduce the wind influence on the performance of conventional TDOA （Time Difference of Arrival） algorithms. First, the sound speed is described as a set of functions of the unknown source location, to approximate the acoustic velocity field distribution in the wind field. Then, they are introduced into the TDOA algorithm, to construct nonlinear equations. Finally, the particle swarm optimization algorithm is used to estimate the source location. The simulation results show that the proposed algorithm can significantly improve the localization accuracy for different wind velocities, source locations and test area sizes. The experimental results show that the proposed method can reduce localization errors to about 40% of the original error in a four nodes localization system.
文摘If we restrict the postman to traversing each edge at most twice in the windypostman problem (WPP), we will get a new problem: 2WPP. An approximation algorithmhas been posed by M. Guan for the WPP. In the present paper, we improve the estimatederror given by M. Guan and show that we can estimate the error for the 2WPP by findinga minimum cost circulation. We also pose a new sufficient condition for the equivalencebetween WPP and 2WPP, which can be checked in polynomial time steps.
基金Supported by the National Natural Science Foundation of China(42205156)Gansu Province University Industry Support Plan Project(2025CYZC-018).
文摘Accurately predicting photovoltaic(PV)power generation is essential for effective power system scheduling.However,increased incidences of sandy weather in recent years pose significant challenges for PV power plants in desert regions.This study addresses the inaccuracies in PV power forecasting under windy-sandy conditions by conducting wind tunnel experiments to evaluate the impact of varying wind speeds and PV panel tilt angles on power generation.Polynomial equations are developed through polynomial surface fitting to establish a relationship between the power loss rate,sand-blowing wind speed,and panel tilt angle.Latin hypercube sampling is used to extend the fitted surface scenarios,simulating real-world variations in PV power generation to enhance the accuracy and applicability of the model.In addition,the model incorporates three uncertainties related to wind direction,module aging,and airflow effects on PV arrays.A case study utilizing data from a PV power plant employs the Pseudo-similar day selection method,enabling a comparative analysis of the predicted outcomes with traditional methodologies.This comparison demonstrates the accuracy and effectiveness of the proposed method for improving PV power prediction under challenging conditions.
