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Data Quality Control Method of a New Drifting Observation Technology Named Drifting Air-Sea Interface Buoy
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作者 LI Shuo WANG Bin +3 位作者 DENG Zeng’an WU Baoqin ZHU Xiande CHEN Zhaohui 《Journal of Ocean University of China》 CAS CSCD 2024年第1期11-22,共12页
An integral quality control(QC)procedure that integrates various QC methods and considers the design indexes and operational status of the instruments for the observations of drifting air-sea interface buoy was develo... An integral quality control(QC)procedure that integrates various QC methods and considers the design indexes and operational status of the instruments for the observations of drifting air-sea interface buoy was developed in the order of basic in-spection followed by targeted QC.The innovative method of combining a moving Hampel filter and local anomaly detection com-plies with statistical laws and physical processes,which guarantees the QC performance of meteorological variables.Two sets of observation data were used to verify the applicability and effectiveness of the QC procedure,and the effect was evaluated using the observations of the Kuroshio Extension Observatory buoy as the reference.The results showed that the outliers in the time series can be correctly identified and processed,and the quality of data improved significantly.The linear correlation between the quality-controlled observations and the reference increased,and the difference decreased.The correlation coefficient of wind speed before and after QC increased from 0.77 to 0.82,and the maximum absolute error decreased by approximately 2.8ms^(-1).In addition,air pressure and relative humidity were optimized by 10^(-3)–10^(-2) orders of magnitude.For the sea surface temperature,the weight of coefficients of the continuity test algorithm was optimized based on the sea area of data acquisition,which effectively expanded the applicability of the algorithm. 展开更多
关键词 drifting air-sea interface buoy quality control oceanic variables meteorological variables continuity test
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Observation of Arctic surface currents using data from a surface drifting buoy
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作者 Hongxia Chen Lina Lin +7 位作者 Long Fan Wangxiao Yang Yinke Dou Bingrui Li Yan He Bin Kong Guangyu Zuo Na Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第1期70-79,共10页
During the 10th Chinese Arctic scientific expedition carried out in the summer of 2019,the surface current in the high-latitude areas of the Arctic Ocean was observed using a self-developed surface drifting buoy,which... During the 10th Chinese Arctic scientific expedition carried out in the summer of 2019,the surface current in the high-latitude areas of the Arctic Ocean was observed using a self-developed surface drifting buoy,which was initially deployed in the Chukchi Sea.The buoy traversed the Chukchi Sea,Chukchi Abyssal Plain,Mendeleev Ridge,Makarov Basin,and Canada Basin over a period of 632 d.After returning to the Mendeleev Ridge,it continued to drift toward the pole.Overall,the track of the buoy reflected the characteristics of the transpolar drift and Chukchi Slope Current,as well as the inertial flow,cross-ridge surface flow,and even the surface disorganized flow for some time intervals.The results showed that:(1)the transpolar drift mainly occurs in the Chukchi Abyssal Plain,Mendeleev Ridge,and western Canada Basin to the east of the ridge where sea ice concentration is high,and the average northward flow velocity in the region between 79.41°N and 86.32°N was 5.1 cm/s;(2)the average surface velocity of the Chukchi Slope Current was 13.5 cm/s,and while this current moves westward along the continental slope,it also extends northwestward across the continental slope and flows to the deep sea;and(3)when sea ice concentration was less than 50%,the inertial flow was more significant(the maximum observed inertial flow was 26 cm/s,and the radius of the inertia circle was 3.6 km). 展开更多
关键词 Chinese National Arctic Research Expedition(CHINARE) surface drifting buoy transpolar drift Chukchi Slope Current inertial flow
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Mechanistic Drifting Forecast Model for A Small Semi-Submersible Drifter Under Tide–Wind–Wave Conditions 被引量:2
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作者 ZHANG Wei-na HUANG Hui-ming +2 位作者 WANG Yi-gang CHEN Da-ke ZHANG lin 《China Ocean Engineering》 SCIE EI CSCD 2018年第1期99-109,共11页
Understanding the drifting motion of a small semi-submersible drifter is of vital importance regarding monitoring surface currents and the floating pollutants in coastal regions. This work addresses this issue by esta... Understanding the drifting motion of a small semi-submersible drifter is of vital importance regarding monitoring surface currents and the floating pollutants in coastal regions. This work addresses this issue by establishing a mechanistic drifting forecast model based on kinetic analysis. Taking tide–wind–wave into consideration, the forecast model is validated against in situ drifting experiment in the Radial Sand Ridges. Model results show good performance with respect to the measured drifting features, characterized by migrating back and forth twice a day with daily downwind displacements. Trajectory models are used to evaluate the influence of the individual hydrodynamic forcing. The tidal current is the fundamental dynamic condition in the Radial Sand Ridges and has the greatest impact on the drifting distance. However, it loses its leading position in the field of the daily displacement of the used drifter. The simulations reveal that different hydrodynamic forces dominate the daily displacement of the used drifter at different wind scales. The wave-induced mass transport has the greatest influence on the daily displacement at Beaufort wind scale 5–6; while wind drag contributes mostly at wind scale 2–4. 展开更多
关键词 in situ drifting experiment mechanistic drifting forecast model tide–wind–wave coupled conditions small semi-submersible drifter daily displacement
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Growth and Resource Accumulation of Drifting Sargassum horneri(Fucales, Phaeophyta) in Response to Temperature and Nitrogen Supply 被引量:4
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作者 YU Jia LI Jingyu +2 位作者 WANG Qiaohan LIU Yan GONG Qingli 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第5期1216-1226,共11页
The abnormal increase of drifting brown alga Sargassum horneri was initially documented in 2007.It formed blooms along the coast of East China Sea and Yellow Sea in 2017.In this study,we investigated the changes of sp... The abnormal increase of drifting brown alga Sargassum horneri was initially documented in 2007.It formed blooms along the coast of East China Sea and Yellow Sea in 2017.In this study,we investigated the changes of specific growth rate and resource accumulation of drifting S.horneri in response to temperature and nitrogen richness at different growth stages under laboratory condition.The investigation lasted from June 2015 to April 2016 with the observation made every two months.The results showed that the life cycle consists of a few growth stages dividable with morphological characteristics.The growth can be divided into shedding and withering(August),rapid growing(October to September),slow growing(February),rapid growing(April)and maturation(June)stages.Under the experimental condition,algal segments were found to grow at temperatures ranging from 5 to 25℃in 12 days even when nitrogen is deficient.A significant difference in the special growth rate(SGR)between nitrogen-enriched and nitrogen-removed treatments was found in most months(P<0.05).SGR was lower in August and February than that in other months.Nitrogen and chlorophyll contents in algal segments were different among different temperatures,nitrogen supply and seasons.Nitrogen content was higher in February and April than that in other months in both nitrogen-enriched and nitrogen-removed treatments.The results showed that the demand of S.horneri for nitrogen increased in spring when it grows fast.It is likely that the high temperature and nitrogen concentration in winter and spring lead to the high biomass accumulation of drifting S.horneri. 展开更多
关键词 nitrogen supply TEMPERATURE cultivation GROWTH stage drifting population SARGASSUM horneri
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Seasonal and inter-annual variations of the primary types of the Arctic sea-ice drifting patterns 被引量:7
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作者 WANG Xiaoyu ZHAO Jinping 《Advances in Polar Science》 2012年第2期72-81,共10页
Abstract Monthly mean sea ice motion vectors and monthly mean sea level pressure (SLP) for the period of 1979-2006 are investigated to understand the spatial and temporal changes of Arctic sea-ice drift. According t... Abstract Monthly mean sea ice motion vectors and monthly mean sea level pressure (SLP) for the period of 1979-2006 are investigated to understand the spatial and temporal changes of Arctic sea-ice drift. According to the distinct differences in monthly mean ice velocity field as well as in the distribution of SLP, there are four primary types in the Arctic Ocean: Beaufort Gyre+Transpolar Drift, Anticyclonic Drift, Cyclonic Drift and Double Gyre Drift. These four types account for 81% of the total, and reveal distinct seasonal variations. The Cyclonic Drift with a large-scale anticlockwise ice motion pattern trends to prevail in summer while the Anticyclonic Drift with an opposite pattern trends to prevail in winter and spring. The prevailing seasons for the Beaufort Gyre+Transpolar Drift are spring and autumn, while the Double Gyre Drift trends to prevail in winter, especially in Feb- ruary. The annual occurring times of the Anticyclonic Drift and the Cyclonic Drift are closely correlated with the yearly mean Arc- tic Oscillation (AO) index, with a correlation coefficient of -0.54 and 0.54 (both significant with the confident level of 99%), re- spectively. When the AO index stays in a high positive (negative) condition, the sea-ice motion in the Arctic Ocean demonstrates a more anticlockwise (clockwise) drifting pattern as a whole. When the AO index stays in a neutral condition, the sea-ice motion becomes much more complicated and more transitional types trend to take place. 展开更多
关键词 sea ice ice drift drifting pattern seasonal and annual variation Arctic Oscillation
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Continuous calibration of inertial platform drifting error parameters 被引量:1
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作者 付振宪 邓正隆 裴听国 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2000年第3期24-26,共3页
Presents a continuous inertial platform drifting test process to simplify the operation of experiment and eliminate the difficulty of Kalman filter’s parameter setting up with the previous discrete multi position tes... Presents a continuous inertial platform drifting test process to simplify the operation of experiment and eliminate the difficulty of Kalman filter’s parameter setting up with the previous discrete multi position testing scheme,and improve the estimation accuracy for each error parameter. 展开更多
关键词 INERTIAL PLATFORM drifting test PARAMETER identification KALMAN filtering.
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Surface circulation derived from drifting buoys in mid- and low-latitude Pacific
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作者 苏京志 李明悝 +2 位作者 侯一筠 尹宝树 方国洪 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2006年第4期333-337,共5页
A dataset of drifting buoys from the Marine Environmental Data Service of Canada was analyzed to map surface circulation of the Pacific. More information of the surface circulation than that acquired before was report... A dataset of drifting buoys from the Marine Environmental Data Service of Canada was analyzed to map surface circulation of the Pacific. More information of the surface circulation than that acquired before was reported in this paper, showing clear and strong western boundary currents, equato- rial currents, and subtropical gyres in the North and South Pacific regions in velocity field, with a more systematic structure in the North Pacific. 展开更多
关键词 drifting buoy surface circulation subtropical gyres
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The memristive conductance studying of an Au/Ti_nO_(2n-1) memristor device based on oxygen vacancy drifting
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作者 邱云生 《科技视界》 2016年第20期226-229,共4页
With the insight of memristor researsh growing continuously,many semiconductor material has been manufactured to various kinds of memristive device.Yet the stabilization of memristive performance haven’t been fulfill... With the insight of memristor researsh growing continuously,many semiconductor material has been manufactured to various kinds of memristive device.Yet the stabilization of memristive performance haven’t been fulfilled,the fathom of memristive-acting mechanism still not being generalized.To put a futher move on low-consuming and high-stable memristive conductance device,we built a high stable double-pair-electrode device,based on the fabrication of TiO_(2-x),which has been generally applied as a n-type semiconductor.Under the constant-repeating cyclic voltammerty;we nailed the memristive quality of our mental/semiconductor thin film device.Moreover,through multifarious analytical processes based on our doping,filming growing path,we build a rational model for our memristor‘s memristive conductance mechanism,which indicated the carrier motion and electron tunnel following the biasing voltage.Our work exhibited a new type of TiO_(2-x)-based memristor,and emerged a new way to explicate the single-stage-switching memristive feature,which might initiate a new guiding ideology in semiconductor memristor’s studying. 展开更多
关键词 TI memristor device based on oxygen vacancy drifting The memristive conductance studying of an Au/Ti_nO
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Test and analysis of mechanism and influential elements of axial drifting of weldment on turning rolls
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作者 王政 乔及森 +2 位作者 许文涛 樊丁 沈凤刚 《China Welding》 EI CAS 2003年第1期50-53,共4页
The mechanism of axial drifting of weldment on welding turning rolls was investigated. The simulation test for influential element has been carried out as well. The results show that axial drifting is caused by unpara... The mechanism of axial drifting of weldment on welding turning rolls was investigated. The simulation test for influential element has been carried out as well. The results show that axial drifting is caused by unparallel between the axis of roller and weldment resulting in axial force. When the helical angle λ between rolls and weldment is from 1°to 6°, the tanλ is linearly related to axial drifting speed v. Increase of number of deflected rollers causes non linear increase of v. The angle of λ makes more effect on speed v than what the angle of deflection does. The turning speed of weldment is proportion to axial drifting speed v. The dead weight of weldment has little effect on speed v. 展开更多
关键词 welding turning rolls axial drifting axial force
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Is the Shark Just Drifting, or Does It Take a Quick Nap?
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作者 Erich K. Ritter 《Open Journal of Animal Sciences》 2020年第1期40-47,共8页
It is unknown if resting sharks can sleep, which is also true for gliding ones. Here, a videotaped bull shark is presented that drifted in an uncontrolled manner for 120 seconds while sinking with 0.1 m/second. Severa... It is unknown if resting sharks can sleep, which is also true for gliding ones. Here, a videotaped bull shark is presented that drifted in an uncontrolled manner for 120 seconds while sinking with 0.1 m/second. Several aspects are discussed to determine if the shown behavior reflects the commonly accepted definition of sleep. Additionally, the idea is also discussed if this state might reflect a “quiet waking state” instead of where the shark still maintained some vigilance despite its general appearance. 展开更多
关键词 drifting MELATONIN PINEAL GLAND SHARK Sleep
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Resistance and Reactance of Monopole Fields Induced by a Test Charge Drifting Off-Axis in a Cold and Collisional Cylindrical Plasma
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作者 M.S.Bawa'aneh A.M.Al-Khateeb Y.-c.Ghim 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第8期49-53,共5页
We study the interaction of a uniform, cold and collisional plasma with a test charged particle moving off-axis at a constant speed down a cylindrical tube with a resistive thick metallic wall. Upon matching the elect... We study the interaction of a uniform, cold and collisional plasma with a test charged particle moving off-axis at a constant speed down a cylindrical tube with a resistive thick metallic wall. Upon matching the electromagnetic field components at all interfaces, the induced monopole electromagnetic fields in the plasma are obtained in the frequency domain. An expression for the plasma electric resistance and reactance is derived and analyzed numerically for some representative parameters. Near the plasma resonant frequency, the plasma resistance evolves with frequency like a parallel RLC resonator with peak resistance at the plasma frequency pe, while the plasma reactance can be capacitive or inductive in nature depending on the frequency under consideration. 展开更多
关键词 In Resistance and Reactance of Monopole Fields Induced by a Test Charge drifting Off-Axis in a Cold and Collisional Cylindrical Plasma
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The Drifting History of the China Main Blocks during Specific Periods and their Tectonic Constraints on Marine Potash Formation
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作者 YAN Maodu ZHANG Dawen 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第S1期272-272,共1页
1 Introduction Most of the world well know potash mines are deposited in marine environment.Regarding the serious potash shortage,no significant progress has been made in marine potash in China,while the terrestrial p... 1 Introduction Most of the world well know potash mines are deposited in marine environment.Regarding the serious potash shortage,no significant progress has been made in marine potash in China,while the terrestrial potash 展开更多
关键词 The drifting History of the China Main Blocks during Specific Periods and their Tectonic Constraints on Marine Potash Formation
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Vertical redistribution of drifting benthic invertebrates in the Kedrovaya River, Primorsky Region of Russia
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作者 Maxim V. Astakhov Victor V. Bogatov 《Open Journal of Ecology》 2014年第2期53-59,共7页
The vertical distribution of morphologically different drifting invertebrates (mayfly and dipteran larvae) in a small salmon river was studied. Drifting invertebrates were caught with the Astakhov’s sampler equipped ... The vertical distribution of morphologically different drifting invertebrates (mayfly and dipteran larvae) in a small salmon river was studied. Drifting invertebrates were caught with the Astakhov’s sampler equipped with three driftnets placed one above another. The average annual drift rate in different levels of a water column was practically the same, while the drift density decreased from the bottom to the surface. Over the course of 24 hours, the drifting organisms did not show clear preference for a particular water layer. Invertebrates were constantly redistributed between the upper and lower levels at approximately 30 - 90 min intervals. This redistribution appears to be linked to the fact that invertebrates of the same taxa, which entered into water column from different bottom sites become active at different times. 展开更多
关键词 Sampling BENTHOS Stream DRIFT VERTICAL Distribution
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Extreme air-sea turbulent fluxes during tropical cyclone Barijat observed by a newly designed drifting buoy
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作者 Xuehan Xie Zexun Wei +3 位作者 Bin Wang Zhaohui Chen Marilena Oltmanns Xiangzhou Song 《Fundamental Research》 CAS CSCD 2024年第5期1225-1234,共10页
Using in situ observations collected by a drifting air-sea interface buoy(DrIB)in the northern South China Sea from August 30 to September 13,2018,the extreme air-sea turbulent fluxes that occurred from September 8 to... Using in situ observations collected by a drifting air-sea interface buoy(DrIB)in the northern South China Sea from August 30 to September 13,2018,the extreme air-sea turbulent fluxes that occurred from September 8 to 13 during tropical cyclone(TC)Barijat were investigated.The most striking features were substantial increases in momentum and heat fluxes,with maximum increases of 10.8 m s−1 in the wind speed(WS),0.73 N m^(-2)in the wind stress,68.1 W m^(-2)in the sensible heat fluxes(SH)and 258.8 W m^(-2)in the latent heat fluxes(LH).The maximum WS,wind stress,SH and LH values amounted to 15.3 m s−1,0.8 N m^(-2),70.9 W m^(-2)and 329.9 W m^(-2),respectively.Using these new DrIB observations,the performance of two state-of-the-art,high-resolution reanalysis products,ERA5 and MERRA2,was assessed.The consistency of the observed values with ERA5 was slightly better than with MERRA2,reflected in higher correlations but both products underestimated the WS during TC conditions.In calm weather conditions,the turbulent heat fluxes were overestimated,because they simulated a too dry and cold atmospheric state,enhancing the air-sea differences in temperature and humidity.Considering that an accurate representation of the air-sea turbulent and momentum fluxes is essential for understanding and predicting ocean and atmospheric variability,our findings indicate that more high-quality temperature and relative humidity observations are required to evaluate and improve existing reanalysis products. 展开更多
关键词 Tropical cyclonesA ir–sea interaction Air–sea turbulent fluxes drifting buoy DrIB observations
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A drifting trajectory prediction model based on object shape and stochastic mo-tion features 被引量:4
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作者 王胜正 聂皓冰 施朝健 《Journal of Hydrodynamics》 SCIE EI CSCD 2014年第6期951-959,共9页
There is a huge demand to develop a method for marine search and rescue(SAR) operators automatically predicting the most probable searching area of the drifting object. This paper presents a novel drifting predictio... There is a huge demand to develop a method for marine search and rescue(SAR) operators automatically predicting the most probable searching area of the drifting object. This paper presents a novel drifting prediction model to improve the accuracy of the drifting trajectory computation of the sea-surface objects. First, a new drifting kinetic model based on the geometry characteristics of the objects is proposed that involves the effects of the object shape and stochastic motion features in addition to the traditional factors of wind and currents. Then, a computer simulation-based method is employed to analyze the stochastic motion features of the drifting objects, which is applied to estimate the uncertainty parameters of the stochastic factors of the drifting objects. Finally, the accuracy of the model is evaluated by comparison with the flume experimental results. It is shown that the proposed method can be used for various shape objects in the drifting trajectory prediction and the maritime search and rescue decision-making system. 展开更多
关键词 sea-surface object searching drifting model drifting trajectory prediction maritime search and rescue
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Observational estimation of heat budgets on drifting ice and open water over the Arctic Ocean 被引量:12
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作者 卞林根 高志球 +3 位作者 陆龙骅 张雅宾 C.Roger X.D.Zhang 《Science China Earth Sciences》 SCIE EI CAS 2003年第6期580-591,共12页
Estimates of the surface heat budget over drifting ice and open water in the Arctic Ocean are made using eddy correlation and flux-profile methods using data obtained from drifting ice and from the R/V Xuelong in the ... Estimates of the surface heat budget over drifting ice and open water in the Arctic Ocean are made using eddy correlation and flux-profile methods using data obtained from drifting ice and from the R/V Xuelong in the Chinese National Arctic Research Expedition during August 19—24,1999. The results show that the net radiation received by the ice surface is mainly lost through the sensible heat flux and the heat flux due to melting ice, and the latent heat flux making small contribution to the heat balance. However, the heat balance of the open water surface was dominated by the radiative flux whereas the latent and sensible heat fluxes and the oceanic heat flux were greater than those on the sea-ice surface. These results emphasize that thermodynamic processes are quite different between air/open water and air/sea-ice over the Arctic Ocean which is important when considering the effect of sea-air-ice interaction on climate change process dur-ing the summer period. 展开更多
关键词 ARCTIC Ocean drifting ice open water turbulence flux heat balance.
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Drifting Fragrant Tea
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作者 RONG BIAN WEI LIANG 《Women of China》 2000年第4期45-,共1页
关键词 drifting Fragrant Tea
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Paleozoic Structural Deformation of Bachu Uplift,Tarim Basin of Northwest China:Implications for Plate Drifting 被引量:4
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作者 何光玉 何治亮 +6 位作者 张洪安 林璐 陈强路 钱一雄 顾忆 竺知新 竺国强 《Journal of China University of Geosciences》 SCIE CSCD 2009年第4期755-762,共8页
Based on high-resolution 2D seismic profiles, the Paleozoic structural deformation char- acteristics of Bachu (巴楚) uplift of northwestern Tarim basin, NW China, are exhibited in this article. The deformation happe... Based on high-resolution 2D seismic profiles, the Paleozoic structural deformation char- acteristics of Bachu (巴楚) uplift of northwestern Tarim basin, NW China, are exhibited in this article. The deformation happened during three main geological periods: the end of Middle-Late Ordovician (O2-3), the end of Early-Middle Devonian (D1-2), and the end of Late Permian (P2). In the Bachu uplift, there developed a series of NW-trending thrust faults and imbricate structures due to the effect of the NW-SE compression stress towards the end of Middle-Late Ordovician (O2-3) (middle Caledonian movement), and there developed some NNE-trending thrust faults and fault blocks under the control of the NEE-SWW compression stress at the end of Early-Middle Devonian (D1-2) (early Hercynian movement). However, at the end of Late Permian (P2) (late Hercynian movement), some NE-trending thrust faults and associated folds developed as a result of the NE-SW compression stress. The first-stage (O2-3) deformation is obviously more violent than those of the latter two stages (D1-2 and P2), which implies that the Tarim plate drifted quickly to the north at around the same time basin. 展开更多
关键词 structural deformation PALEOZOIC plate drift Bachu uplift Tarim.
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Estimation of buoy drifting based on adaptive parameter-varying time scale Kalman filter 被引量:3
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作者 Han Xue Tian Chai 《Journal of Control and Decision》 EI 2021年第3期353-362,共10页
To solve Kalman filter with dynamic time scale problem,an adaptive parameter-varying time scale kalman filter(APVTS-KF)is designed.An adaptive mechanism for choosing the covariance of state noise is designed.APVTS-KF ... To solve Kalman filter with dynamic time scale problem,an adaptive parameter-varying time scale kalman filter(APVTS-KF)is designed.An adaptive mechanism for choosing the covariance of state noise is designed.APVTS-KF is used to estimate the buoy drifting trajectory with different report intervals.Position drifting data of four buoys are used to test the proposed algorithm.The influence of report interval,drifting distance,adaptive factor and noise covariance are analysed and compared.The experimental results and error analysis show that APVTS-KF is better than other algorithms in trajectory estimation.Thus,Kalman filtering can be used for accurate trajectory estimation in the actual situation of buoy drifting with dynamic time intervals. 展开更多
关键词 Kalman filter buoy drift state estimation
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Dispersal of invasive species by drifting 被引量:1
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作者 M.C. VAN RIEL G. VAN DER VELDE A. BIJ DE VAATE 《Current Zoology》 SCIE CAS CSCD 北大核心 2011年第6期818-827,共10页
Drifting can be an effective way for aquatic organisms to disperse and colonise new areas. Increasing connectivity between European large rivers facilitates invasion by drifting aquatic macroinvertebrates. The present... Drifting can be an effective way for aquatic organisms to disperse and colonise new areas. Increasing connectivity between European large rivers facilitates invasion by drifting aquatic macroinvertebrates. The present study shows that high abundances of invasive species drift in the headstream of the river Rhine. Dikerogammarus villosus and Chelicorophium cur- vispinum represented up to 90% of the total of drifting macroinvertebrates. Drift activity shows seasonal and diel patterns. Most species started drifting in spring and were most abundant in the water column during the summer period. Drift activity was very low during the winter period. Diel patterns were apparent; most species, including D. villosus, drifted during the night. Drifting macroinvertebrates colonised stony substrate directly from the water column. D. villosus generally colonised the substrate at night, while higher numbers of C. curvispinum colonised the substrate during the day. It is very likely that drifting functions as a disper- sal mechanism for crustacean invaders. Once waterways are connected, these species are no longer necessarily dependent on dispersal vectors other than drift for extending their distribution range 展开更多
关键词 AMPHIPODS INVADERS COLONIZATION DRIFT Daily rhythms Seasonal variation
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