There is a vast upwelling area induced by the southeast monsoon in the waters off South Java,making the region an important fishing ground.Climate events can affect the variation of upwelling,but oceanographers have d...There is a vast upwelling area induced by the southeast monsoon in the waters off South Java,making the region an important fishing ground.Climate events can affect the variation of upwelling,but oceanographers have different understandings on the extent to which climate events control upwelling in this area,which leads to a lack of basis for studies on the evaluation and mechanisms of the variability of fishery resources in the region.The correlation between environmental parameters,including surface temperature(SST),chlorophyll-a(Chl-a)concentration,and climate event indices in South Java from 2003 to 2020 was analyzed.Results show that the Indian Ocean Dipole(IOD)has a greater influence on the interannual variability of upwelling intensity than ENSO.During the IOD,variations in equatorial latitudinal winds excite different types of Kelvin waves that anomalously deepen or shallow the thermocline,which is the main cause of anomalous variations in upwelling,independent of variations in the local wind field.A correlation between the interannual variability in upwelling and the annual catches was revealed,showing that climatic events indirectly affect fishery resources through upwelling effects.During positive IOD/El Niño periods,strong upwelling delivers more nutrients to the surface layer,which favors fish growth and reproduction,resulting in higher annual catches.A negative IOD/La Niña,on the other hand,leads to weaker upwelling and fewer nutrients into the surface waters.Fish tend to move in deeper waters,making traditional fishing methods less efficient and consequently lower annual catches.展开更多
Radio frequency interference (RFI) is greatly harmful to Global Navigation Satellite System (GNSS) receivers. Sweep interference is one of the RFI for the GNSS receivers, which can degrade the performance of GNSS rece...Radio frequency interference (RFI) is greatly harmful to Global Navigation Satellite System (GNSS) receivers. Sweep interference is one of the RFI for the GNSS receivers, which can degrade the performance of GNSS receivers seriously. In this paper, the Fractional Fourier Transform (FrFT) of time-frequency analysis is proposed in the GNSS interference detection and suppression. The FrFT method is tested for detecting and suppressing sweep interference, which is generated by a GNSS jammer. In the simulation experiment, the GNSS signal affected by sweep frequency interference is successfully captured after interference suppression by using the proposed method, which shows its effectiveness. The interference detection performance of the FrFT method is compared with the conventional techniques such as Short-Time Fourier transform (STFT) and Wigner-Ville distribution (WVD). The detection performance is improved by about a least one order of magnitude. In the aspect of interference suppression, a threshold method based on detection probability is proposed, and the performance of the proposed threshold method is compared with the conventional threshold methods. In the result, the interference tolerance is increased by 5 dB compared with the mean threshold method, and by 9 dB compared with the fixed threshold.展开更多
In this paper, we study the continuum modeling of traffic dynamics for two-lane freeways. A new dynamics model is proposed, which contains the speed gradient-based momentum equations derived from a car-following theor...In this paper, we study the continuum modeling of traffic dynamics for two-lane freeways. A new dynamics model is proposed, which contains the speed gradient-based momentum equations derived from a car-following theory suited to two-lane traffic flow. The conditions for securing the linear stability of the new model are presented. Numerical tests are can'ied out and some nonequilibrium phenomena are observed, such as small disturbance instability, stop-and-go waves, local clusters and phase transition.展开更多
In this paper, the two-lane traffic are studied by using the lane-changing rules in the car-following models. The simulation show that the frequent lane changing occurs when the lateral distance in car following activ...In this paper, the two-lane traffic are studied by using the lane-changing rules in the car-following models. The simulation show that the frequent lane changing occurs when the lateral distance in car following activities is considered and it gives rise to oscillating waves. In contrast, if the lateral distance is not considered (or considered occasionally), the lane changing appears infrequently and soliton waves occurs. This implies that the stabilization mechanism no longer functions when the lane changing is permitted. Since the oscillating and soliton waves correspond to the unstable and metastable flow regimes, respectively, our study verifies that a phase transition may occur as a result of the lane changing.展开更多
Physical oceanography plays an important role in the formation of submarine sediments,and the distribution of nutriments and biocenoses in seamounts.The M4 seamount is located in the Caroline Island Ridge of the Weste...Physical oceanography plays an important role in the formation of submarine sediments,and the distribution of nutriments and biocenoses in seamounts.The M4 seamount is located in the Caroline Island Ridge of the Western Pacific Ocean.The physical properties around M4 seamount are preliminarily analyzed based on the in-situ data obtained in summer 2017 in Caroline M4 seamount and open-sourced data.We found that the water in the upper 200 m is controlled by the westward North Equatorial Current(NEC),while the water between 300-1000 m is dominated by the eastward North Equatorial Undercurrent(NEUC).The current direction fluctuates significantly below 300 m at upstream stations.At the same depth of the lee sides,the current direction changes with the distance from seamount.These are likely caused by the obstacle of M4 seamount.The calculation results show that there is an anticyclonic cap above M4 seamount caused by tidal rectification.Tidal currents in M4 seamount are squeezed by the topography and amplified,and the amplified tidal currents play a dominant role in M4 seamount.First,the circulation system generated by the interaction of the amplified tidal current and M4 seamount drives the upward/downward movement of the isotherms.Secondly,the thickness of the surface turbulent layer is changed with the tidal phase.Thirdly,high turbulent diffusivities are found in the bottom of M4 seamount,and these are most likely attributed to the turbulent mixing induced by the mutual effect between semidiurnal tidal currents and steep bathymetry.This article of physical oceanography provides scientific basis for further analysis of the distribution of biological community and deposition mechanism in M4 seamount.展开更多
The spatial structure of the Arctic sea ice concentration(SIC)variability and the connection to atmospheric as well as radiative forcing during winter and summer for the 1979–2017 period are investigated.The interann...The spatial structure of the Arctic sea ice concentration(SIC)variability and the connection to atmospheric as well as radiative forcing during winter and summer for the 1979–2017 period are investigated.The interannual variability with different spatial characteristics of SIC in summer and winter is extracted using the empirical orthogonal function(EOF)analysis.The present study confirms that the atmospheric circulation has a strong influence on the SIC through both dynamic and thermodynamic processes,as the heat flux anomalies in summer are radiatively forced while those in winter contain both radiative and“circulation-induced”components.Thus,atmospheric fluctuations have an explicit and extensive influence to the SIC through complex mechanisms during both seasons.Moreover,analysis of a variety of atmospheric variables indicates that the primary mechanism about specific regional SIC patterns in Arctic marginal seas are different with special characteristics.展开更多
The climate variability induced by the El Nino-Southern Oscillation(ENSO)cycle drives significant changes in the physical state of the tropical Western Pacific,which has important impacts on the upper ocean carbon cyc...The climate variability induced by the El Nino-Southern Oscillation(ENSO)cycle drives significant changes in the physical state of the tropical Western Pacific,which has important impacts on the upper ocean carbon cycle.During 2015-2016,a super El Nino event occurred in the equatorial Pacific.Suspended particulate matter(SPM)data and related environmental observations in the tropical Western Pacific were obtained during two cruses in Dec.2014 and 2015,which coincided with the early and peak stages of this super El Nino event.Compared with the marine environments in the tropical Western Pacific in Dec.2014,an obviously enhanced upwelling occurred in the Mindanao Dome region;the nitrate concentration in the euphotic zone almo st tripled;and the size,mass concentration,and volume concentration of SPM obviously increased in Dec.2015.The enhanced upwelling in the Mindanao Dome region carried cold but eutrophic water upward from the deep ocean to shallow depths,even into the euphotic zone,which disrupted the previously N-limited conditions and induced a remarkable increase in phytoplankton blooms in the euphotic zone.The se results reveal the mechanism of how nutrient-limited ecosystems in the tropical Western Pacific respond to super El Nino events.In the context of the ENSO cycle,if predicted changes in biogenic particles occur,the proportion of carbon storage in the tropical Western Pacific is estimated to be increased by more than 52%,ultimately affecting the regional and possibly even global carbon cycle.This paper highlights the prospect for long-term prediction of the impact of a super El Nino event on the global carbon cycle and has profound implications for understanding El Nino events.展开更多
Seamounts aff ect the surrounding physical oceanography and form unique dynamic processes.The infl uences of these processes on biological and sedimentary distributions are quite diff erent in seamount areas at diff e...Seamounts aff ect the surrounding physical oceanography and form unique dynamic processes.The infl uences of these processes on biological and sedimentary distributions are quite diff erent in seamount areas at diff erent depths.The Y3 seamount is located in the Yap Arc of the tropical Western Pacifi c Ocean.The water depth of its summit is~280 m.Based on fi eld data obtained in December 2014 and other open-access data,the physical oceanography around the Y3 seamount was preliminarily analyzed.The results show that the upper layer(0-150 m)was under the infl uence of the westward-fl owing North Equatorial Current(NEC),while the eastward-fl owing North Equatorial Undercurrent(NEUC)controlled the water between 200-800 m.The NEC was strong and steady,but the NEUC was disturbed by the Y3 seamount.The cold dome above the Y3 seamount was not caused by a Taylor cap or tidal rectifi cation but probably by upwelling during the survey time.Tidal currents were squeezed against topography and greatly amplifi ed in the Y3 seamount.The thicknesses of the surface turbulent layers were greatly infl uenced by the spring-neap tidal cycle.The turbulent diff usivities in the sea surface layer above the Y3 seamount were much larger than those in the open ocean.Calculations showed that the surface wind stress greatly aff ected the turbulent mixing in the surface layer of the Y3 seamount.The reciprocal action between the amplifi ed tidal currents and topography was the most likely cause of the turbulent mixing near the bottom of the Y3 seamount.This study can provide a scientifi c basis for further study of biological and depositional characteristics at the Y3 seamount.展开更多
In this paper, a new car-following model is presented, taking into account the anticipation of potential lane changing by the leading vehicle. The stability condition of the model is obtained by using the linear stabi...In this paper, a new car-following model is presented, taking into account the anticipation of potential lane changing by the leading vehicle. The stability condition of the model is obtained by using the linear stability theory. The modified Korteweg-de Vries (KdV) equation is constructed and solved, and three types of traffic flow in the headway-sensitivity space, namely stable, metastable and unstable ones, are classified. Both the analytical and simu- lation results show that anxiety about lane changing does indeed have an influence on driving behavior and that a consideration of lane changing probability in the car-following model could stabilize traffic flows. The quantitative relationship between stability improvement and lane changing probability is also investigated.展开更多
Sea ice export through the Baffin Bay plays a vital role in modulating the sea ice cover variability in the Labrador Sea.In this study,satellite-derived sea ice products are used to obtain the sea ice area flux(SIAF)t...Sea ice export through the Baffin Bay plays a vital role in modulating the sea ice cover variability in the Labrador Sea.In this study,satellite-derived sea ice products are used to obtain the sea ice area flux(SIAF)through the three passages in the Baffin Bay(referred to as A,B,and C for the north,middle,and south passages,respectively).The spatial variability of the monthly sea ice drift in the Baffin Bay is presented.The interannual variability and trends in SIAF via the three passages are outlined.The connection to several large-scale atmospheric circulation modes is assessed.Over the period of 1988-2015,the average annual(October to the following September)SIAF amounts to 555×10^(3) km^(2),642×10^(3) km^(2),and 551×10^(3) km^(2) through Passages A,B,and C,respectively.These quantities are less than that observed through the Fram Strait(FS,707×10^(3) km^(2))of the corresponding period.The positive trends in annual SIAF,on the order of 53.1×10^(3) km^(2)/(10 a)and 43.2×10^(3) km^(2)/(10 a)(significant at the 95%confidence level),are identified at Passages A and B,respectively.The trend of the south passage(C),however,is slightly negative(-13.3×10^(3) km^(2)/(10 a),not statistically significant).The positive trends in annual SIAF through the Passages A and B are primarily attributable to the significant increases after 2000.The connection between the Baffin Bay sea ice export and the North Atlantic Oscillation is not significant over the studied period.By contrast,the association with the cross-gate sea level pressure difference is robust in the Baffin Bay(R equals 0.69 to 0.71,depending on the passages considered),but relatively weaker than that over FS(R=0.74).展开更多
This study proposes a thought to employ detergent⁃like renewable low⁃cost crude extract of Gleditsia sinensis lam(GSL)as green corrosion inhibitor for mild steel in HCl solution.Crude Gleditsia sinensis lam extract(GS...This study proposes a thought to employ detergent⁃like renewable low⁃cost crude extract of Gleditsia sinensis lam(GSL)as green corrosion inhibitor for mild steel in HCl solution.Crude Gleditsia sinensis lam extract(GSLE)was gained at mild conditions by simply refluxing in ethanol with a Soxhlet extractor.The target GSLE extract exhibited regular self⁃organization in mixed solvents of organic solvents/H2O such as ethanol/H2 O(v/v,50/50)at room temperature,which was evidenced by different means including scanning electron microscopy,transmission electron microscopy,and dynamic light scattering.The study demonstrates that the yielded assemblies of the crude extract of GSLE displayed chemical adsorption on the studied mild steel sample surfaces.Furthermore,the formed stable crude extract assemblies of GSL presented outstanding anti⁃corrosion capability in 1.0 mol/L HCl aqueous solution based on electrochemical measurements including polarization curves and impedance spectroscopy.It is discovered that the maximal corrosion inhibition efficiency could reach approximate 95%.The molecular modeling was performed to acquire the nature of frontier orbitals of the main representative chemical components of crude GSLE for deep understanding of chemical interactions with iron.The results presented herein would guide us to seek sustainable environmentally friendly low⁃cost detergent⁃like plant crude extracts for corrosion inhibition of various metals in aggressive acid environments.展开更多
This paper proposes the application strategy of the intelligent technology in electronic engineering automation control. Artificial intelligence technology is about to realize the calculation of perception, reasoning ...This paper proposes the application strategy of the intelligent technology in electronic engineering automation control. Artificial intelligence technology is about to realize the calculation of perception, reasoning and behavior study of it is different from most of the psychology, because it is more of an emphasis on the calculation, the artificial intelligence is also different from most of the computer science as because it is more of an emphasis on the perception, reasoning, and behavior, and future applications of artificial intelligence is beyond imagination. Regarding the multi-agent system target identification data fusion, the goal type is a proposition, each intelligent body gives through processing regarding the goal type judgment result is evidence, we discussed in detail of the essential applications on the item that will promote the further development.展开更多
This paper discussed the application strategy of the computer network technology in the electronic information engineering. The use of computer network management technology, designed to maximize the effectiveness of ...This paper discussed the application strategy of the computer network technology in the electronic information engineering. The use of computer network management technology, designed to maximize the effectiveness of computer network operations, while ensuring network management security. With the advent of the digital age, the computer network has been basically popular, so the computer network management technology research value and application value is more prominent become a digital information technology research one of the hot spots.. Good antivirus software can be easily installed in a few minutes to each NT server in the organization, and can be downloaded and distributed to all the target machine, set by the network administrator and management, it will work with the operating system and other security measures are tightly integrated to become part of the network security management, and automatically provide the best network virus defense measures. In the future, more integration of the methodologies will be considered and discussed.展开更多
Glycine max L.accumulates a large amount of isoflavonoid compounds,which is beneficial for plant defense,plant-microbe symbiotic interactions,and human health.Several CYP450 subfamily genes are involved in the flavono...Glycine max L.accumulates a large amount of isoflavonoid compounds,which is beneficial for plant defense,plant-microbe symbiotic interactions,and human health.Several CYP450 subfamily genes are involved in the flavonoid biosynthetic pathway in plants.In the present study,we found 24 CYP82 subfamily genes were differentially expressed in various tissues of soybean,in Phytophthora sojae-infected soybean varieties and in soybean hairy roots treated with cell wall glucan elicitor.Six of them(GmCYP82A2,GmCYP82A3,GmCYP82A4,GmCYP82A23,GmCYP82C20 and GmCYP82D26)were co-expressed with other known isoflavonoid pathway genes in soybean.Their enzymatic activity in yeast feeding assays showed that only GmCYP82D26 was able to convert naringenin to daidzein with both aryl migration and dehydration function.When GmCYP82D26 was over-expressed in soybean hairy roots,the contents of the two major isoflavonoid aglycones in soybean(daidzein and genistein)were reduced,but total flavonoids were not affected.When GmCYP82D26 was suppressed by RNAi in the hairy roots,daidzein content was decreased but genistein content was increased,with unchanged total flavonoid content.GmCYP82D26 was found to be localized in the endoplasmic reticulum at subcellular level when transiently expressed in tobacco leaf epidermis.GmCYP82D26 gene was preferentially expressed in roots,with low expression level in other tissues in soybean.Homology modeling and molecular docking showed that GmCYP82D26 could form hydrogen bond with both HEM and naringenin at C5-OH and C4 carbonyl.All these results indicated that GmCYP82D26 possesses new and dual enzymatic activity,which bridges the two branches(daidzein and genistein branch)of isoflavonoid pathway in soybean.展开更多
The corrosion behavior of cupronickel alloy immersed in the simulated seawater in or without the presence of sulfate-reducing bacteria (SRB) was studied. The results of scanning electronic microscopy and electrochem...The corrosion behavior of cupronickel alloy immersed in the simulated seawater in or without the presence of sulfate-reducing bacteria (SRB) was studied. The results of scanning electronic microscopy and electrochemical impedance spectra reveal that corrosion of the sample immersed in the simulated seawater with SRB was more serious than that immersed in the simulated seawater without SRB. The atomic force microscopy images show that after immersion for 15 days, the surface roughness of the sample in the simulated seawater with SRB was higher than that of the sample in the simulated seawater without SRB. The analysis of confocal laser scanning microscopy indicates that the average depth of the pits on the surface of the sample in the simulated seawater with SRB was almost twice deeper than that of the sample in the simulated seawater without SRB.展开更多
Data envelopment analysis (DEA) is an effective non-parametric method for measuring the relative efficiencies of decision making units (DMUs) with multiple inputs and outputs. In many real situations, the internal...Data envelopment analysis (DEA) is an effective non-parametric method for measuring the relative efficiencies of decision making units (DMUs) with multiple inputs and outputs. In many real situations, the internal structure of DMUs is a two-stage network process with shared inputs used in both stages and common outputs produced by the both stages. For example, hospitals have a two-stage network structure. Stage 1 consumes resources such as information technology system, plant, equipment and admin personnel to generate outputs such as medical records, laundry and housekeeping. Stage 2 consumes the same set of resources used by stage 1 (named shared inputs) and the outputs generated by stage 1 (named intermediate measures) to provide patient services. Besides, some of outputs, for instance, patient satisfaction degrees, are generated by the two individual stages together (named shared outputs). Since some of shared inputs and outputs are hard split up and allocated to each individual stage, it needs to develop two-stage DEA methods for evaluating the performance of two-stage network processes in such problems. This paper extends the centralized model to measure the DEA efficiency of the two-stage process with non split-table shared inputs and outputs. A weighted additive approach is used to combine the two individual stages. Moreover, additive efficiency decomposition models are developed to simultaneously evaluate the maximal and the minimal achievable efficiencies for the individual stages. Finally, an example of 17 city branches of China Construction Bank in Anhui Province is employed to illustrate the proposed approach.展开更多
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB42010203,XDA19060401)the National Natural Science Foundation of China(Nos.42176090,41776011)。
文摘There is a vast upwelling area induced by the southeast monsoon in the waters off South Java,making the region an important fishing ground.Climate events can affect the variation of upwelling,but oceanographers have different understandings on the extent to which climate events control upwelling in this area,which leads to a lack of basis for studies on the evaluation and mechanisms of the variability of fishery resources in the region.The correlation between environmental parameters,including surface temperature(SST),chlorophyll-a(Chl-a)concentration,and climate event indices in South Java from 2003 to 2020 was analyzed.Results show that the Indian Ocean Dipole(IOD)has a greater influence on the interannual variability of upwelling intensity than ENSO.During the IOD,variations in equatorial latitudinal winds excite different types of Kelvin waves that anomalously deepen or shallow the thermocline,which is the main cause of anomalous variations in upwelling,independent of variations in the local wind field.A correlation between the interannual variability in upwelling and the annual catches was revealed,showing that climatic events indirectly affect fishery resources through upwelling effects.During positive IOD/El Niño periods,strong upwelling delivers more nutrients to the surface layer,which favors fish growth and reproduction,resulting in higher annual catches.A negative IOD/La Niña,on the other hand,leads to weaker upwelling and fewer nutrients into the surface waters.Fish tend to move in deeper waters,making traditional fishing methods less efficient and consequently lower annual catches.
文摘Radio frequency interference (RFI) is greatly harmful to Global Navigation Satellite System (GNSS) receivers. Sweep interference is one of the RFI for the GNSS receivers, which can degrade the performance of GNSS receivers seriously. In this paper, the Fractional Fourier Transform (FrFT) of time-frequency analysis is proposed in the GNSS interference detection and suppression. The FrFT method is tested for detecting and suppressing sweep interference, which is generated by a GNSS jammer. In the simulation experiment, the GNSS signal affected by sweep frequency interference is successfully captured after interference suppression by using the proposed method, which shows its effectiveness. The interference detection performance of the FrFT method is compared with the conventional techniques such as Short-Time Fourier transform (STFT) and Wigner-Ville distribution (WVD). The detection performance is improved by about a least one order of magnitude. In the aspect of interference suppression, a threshold method based on detection probability is proposed, and the performance of the proposed threshold method is compared with the conventional threshold methods. In the result, the interference tolerance is increased by 5 dB compared with the mean threshold method, and by 9 dB compared with the fixed threshold.
文摘In this paper, we study the continuum modeling of traffic dynamics for two-lane freeways. A new dynamics model is proposed, which contains the speed gradient-based momentum equations derived from a car-following theory suited to two-lane traffic flow. The conditions for securing the linear stability of the new model are presented. Numerical tests are can'ied out and some nonequilibrium phenomena are observed, such as small disturbance instability, stop-and-go waves, local clusters and phase transition.
基金The project supported by the National Natural Science Foundation of China (70521001, 10404025, 10532060)the National Basic Research Program of China (2006CB705503) the Research Grants Council of the Hong Kong Special Administrative Region (HKU7031/02E, HKU7187/05E).
文摘In this paper, the two-lane traffic are studied by using the lane-changing rules in the car-following models. The simulation show that the frequent lane changing occurs when the lateral distance in car following activities is considered and it gives rise to oscillating waves. In contrast, if the lateral distance is not considered (or considered occasionally), the lane changing appears infrequently and soliton waves occurs. This implies that the stabilization mechanism no longer functions when the lane changing is permitted. Since the oscillating and soliton waves correspond to the unstable and metastable flow regimes, respectively, our study verifies that a phase transition may occur as a result of the lane changing.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences (Nos.XDA19060401,XDB42010203,XDA23050503)the Science and Technology Basic Resources Investigation Program of China (No.2017FY100802)。
文摘Physical oceanography plays an important role in the formation of submarine sediments,and the distribution of nutriments and biocenoses in seamounts.The M4 seamount is located in the Caroline Island Ridge of the Western Pacific Ocean.The physical properties around M4 seamount are preliminarily analyzed based on the in-situ data obtained in summer 2017 in Caroline M4 seamount and open-sourced data.We found that the water in the upper 200 m is controlled by the westward North Equatorial Current(NEC),while the water between 300-1000 m is dominated by the eastward North Equatorial Undercurrent(NEUC).The current direction fluctuates significantly below 300 m at upstream stations.At the same depth of the lee sides,the current direction changes with the distance from seamount.These are likely caused by the obstacle of M4 seamount.The calculation results show that there is an anticyclonic cap above M4 seamount caused by tidal rectification.Tidal currents in M4 seamount are squeezed by the topography and amplified,and the amplified tidal currents play a dominant role in M4 seamount.First,the circulation system generated by the interaction of the amplified tidal current and M4 seamount drives the upward/downward movement of the isotherms.Secondly,the thickness of the surface turbulent layer is changed with the tidal phase.Thirdly,high turbulent diffusivities are found in the bottom of M4 seamount,and these are most likely attributed to the turbulent mixing induced by the mutual effect between semidiurnal tidal currents and steep bathymetry.This article of physical oceanography provides scientific basis for further analysis of the distribution of biological community and deposition mechanism in M4 seamount.
基金The National Natural Science Foundation of China under contract Nos 41406215 and 41706194a fund provided by the Qingdao National Laboratory for Marine Science and Technologythe National Natural Science Foundation of China(NSFC)-Shandong Joint Fund for Marine Science Research Centers under contract No.U1606401.
文摘The spatial structure of the Arctic sea ice concentration(SIC)variability and the connection to atmospheric as well as radiative forcing during winter and summer for the 1979–2017 period are investigated.The interannual variability with different spatial characteristics of SIC in summer and winter is extracted using the empirical orthogonal function(EOF)analysis.The present study confirms that the atmospheric circulation has a strong influence on the SIC through both dynamic and thermodynamic processes,as the heat flux anomalies in summer are radiatively forced while those in winter contain both radiative and“circulation-induced”components.Thus,atmospheric fluctuations have an explicit and extensive influence to the SIC through complex mechanisms during both seasons.Moreover,analysis of a variety of atmospheric variables indicates that the primary mechanism about specific regional SIC patterns in Arctic marginal seas are different with special characteristics.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB42010203,XDA19060401,XDA23050503)the Science&Technology Basic Resources Investigation Program of China(No.2017FY100802)+1 种基金the Open Fund for Key Laboratory of Mar.Geol.and Environment,Institute of Oceanology,Chinese Academy of Sciences(No.MGE2019KG03)the Qingdao(Laoshan)Postdoctoral Applied Research Proj ect in 2019(No.Y9KY161)。
文摘The climate variability induced by the El Nino-Southern Oscillation(ENSO)cycle drives significant changes in the physical state of the tropical Western Pacific,which has important impacts on the upper ocean carbon cycle.During 2015-2016,a super El Nino event occurred in the equatorial Pacific.Suspended particulate matter(SPM)data and related environmental observations in the tropical Western Pacific were obtained during two cruses in Dec.2014 and 2015,which coincided with the early and peak stages of this super El Nino event.Compared with the marine environments in the tropical Western Pacific in Dec.2014,an obviously enhanced upwelling occurred in the Mindanao Dome region;the nitrate concentration in the euphotic zone almo st tripled;and the size,mass concentration,and volume concentration of SPM obviously increased in Dec.2015.The enhanced upwelling in the Mindanao Dome region carried cold but eutrophic water upward from the deep ocean to shallow depths,even into the euphotic zone,which disrupted the previously N-limited conditions and induced a remarkable increase in phytoplankton blooms in the euphotic zone.The se results reveal the mechanism of how nutrient-limited ecosystems in the tropical Western Pacific respond to super El Nino events.In the context of the ENSO cycle,if predicted changes in biogenic particles occur,the proportion of carbon storage in the tropical Western Pacific is estimated to be increased by more than 52%,ultimately affecting the regional and possibly even global carbon cycle.This paper highlights the prospect for long-term prediction of the impact of a super El Nino event on the global carbon cycle and has profound implications for understanding El Nino events.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB42010203,XDA19060401,XDA23050503)the National Natural Science Foundation of China(No.42176090)。
文摘Seamounts aff ect the surrounding physical oceanography and form unique dynamic processes.The infl uences of these processes on biological and sedimentary distributions are quite diff erent in seamount areas at diff erent depths.The Y3 seamount is located in the Yap Arc of the tropical Western Pacifi c Ocean.The water depth of its summit is~280 m.Based on fi eld data obtained in December 2014 and other open-access data,the physical oceanography around the Y3 seamount was preliminarily analyzed.The results show that the upper layer(0-150 m)was under the infl uence of the westward-fl owing North Equatorial Current(NEC),while the eastward-fl owing North Equatorial Undercurrent(NEUC)controlled the water between 200-800 m.The NEC was strong and steady,but the NEUC was disturbed by the Y3 seamount.The cold dome above the Y3 seamount was not caused by a Taylor cap or tidal rectifi cation but probably by upwelling during the survey time.Tidal currents were squeezed against topography and greatly amplifi ed in the Y3 seamount.The thicknesses of the surface turbulent layers were greatly infl uenced by the spring-neap tidal cycle.The turbulent diff usivities in the sea surface layer above the Y3 seamount were much larger than those in the open ocean.Calculations showed that the surface wind stress greatly aff ected the turbulent mixing in the surface layer of the Y3 seamount.The reciprocal action between the amplifi ed tidal currents and topography was the most likely cause of the turbulent mixing near the bottom of the Y3 seamount.This study can provide a scientifi c basis for further study of biological and depositional characteristics at the Y3 seamount.
基金the National Natural Science Foundation of China (70701002,70521001)the National Basic Research Program of China (2006CB705503)the Research Grants Council of the Hong Kong Special Administrative Region (HKU7187/05E)
文摘In this paper, a new car-following model is presented, taking into account the anticipation of potential lane changing by the leading vehicle. The stability condition of the model is obtained by using the linear stability theory. The modified Korteweg-de Vries (KdV) equation is constructed and solved, and three types of traffic flow in the headway-sensitivity space, namely stable, metastable and unstable ones, are classified. Both the analytical and simu- lation results show that anxiety about lane changing does indeed have an influence on driving behavior and that a consideration of lane changing probability in the car-following model could stabilize traffic flows. The quantitative relationship between stability improvement and lane changing probability is also investigated.
基金The National Key Research and Development Program of China under contract Nos 2016YFA0600102,2017YFC1405106,2016YFC1402707,and 2019YFE0114800the General Project of Natural Science Foundation of Shandong Province under contract No.ZR2020MD100+4 种基金the Key Deployment Project of Centre for Ocean Mega Science,Chinese Academy of Sciences,under contract No.COMS2020Q12the National Natural Science Foundation of China under contract Nos 42076185 and 41406215the Open Fund for the Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences under contract No.MGE2020KG04the Key R&D Project of Shandong Province under contract No.2019GSF111017the NSFCShandong Joint Fund for Marine Science Research Centers under contract No.U1606401.
文摘Sea ice export through the Baffin Bay plays a vital role in modulating the sea ice cover variability in the Labrador Sea.In this study,satellite-derived sea ice products are used to obtain the sea ice area flux(SIAF)through the three passages in the Baffin Bay(referred to as A,B,and C for the north,middle,and south passages,respectively).The spatial variability of the monthly sea ice drift in the Baffin Bay is presented.The interannual variability and trends in SIAF via the three passages are outlined.The connection to several large-scale atmospheric circulation modes is assessed.Over the period of 1988-2015,the average annual(October to the following September)SIAF amounts to 555×10^(3) km^(2),642×10^(3) km^(2),and 551×10^(3) km^(2) through Passages A,B,and C,respectively.These quantities are less than that observed through the Fram Strait(FS,707×10^(3) km^(2))of the corresponding period.The positive trends in annual SIAF,on the order of 53.1×10^(3) km^(2)/(10 a)and 43.2×10^(3) km^(2)/(10 a)(significant at the 95%confidence level),are identified at Passages A and B,respectively.The trend of the south passage(C),however,is slightly negative(-13.3×10^(3) km^(2)/(10 a),not statistically significant).The positive trends in annual SIAF through the Passages A and B are primarily attributable to the significant increases after 2000.The connection between the Baffin Bay sea ice export and the North Atlantic Oscillation is not significant over the studied period.By contrast,the association with the cross-gate sea level pressure difference is robust in the Baffin Bay(R equals 0.69 to 0.71,depending on the passages considered),but relatively weaker than that over FS(R=0.74).
基金the National Natural Science Foundation of China(Grant Nos.21376282,21676035,and 21878029)the Graduate Student Research Innovation Project,Chongqing University(Grant No.CYB18046)+2 种基金the Chongqing Science and Technology Commission(Grant No.cstc2018jcyjAX0668)the China Postdoctoral Science Foundation(Grant Nos.22012T50762 and 2011M501388)the Fundamental Research Funds for the Central Universities(Grant No.2018CDXYHG0028)。
文摘This study proposes a thought to employ detergent⁃like renewable low⁃cost crude extract of Gleditsia sinensis lam(GSL)as green corrosion inhibitor for mild steel in HCl solution.Crude Gleditsia sinensis lam extract(GSLE)was gained at mild conditions by simply refluxing in ethanol with a Soxhlet extractor.The target GSLE extract exhibited regular self⁃organization in mixed solvents of organic solvents/H2O such as ethanol/H2 O(v/v,50/50)at room temperature,which was evidenced by different means including scanning electron microscopy,transmission electron microscopy,and dynamic light scattering.The study demonstrates that the yielded assemblies of the crude extract of GSLE displayed chemical adsorption on the studied mild steel sample surfaces.Furthermore,the formed stable crude extract assemblies of GSL presented outstanding anti⁃corrosion capability in 1.0 mol/L HCl aqueous solution based on electrochemical measurements including polarization curves and impedance spectroscopy.It is discovered that the maximal corrosion inhibition efficiency could reach approximate 95%.The molecular modeling was performed to acquire the nature of frontier orbitals of the main representative chemical components of crude GSLE for deep understanding of chemical interactions with iron.The results presented herein would guide us to seek sustainable environmentally friendly low⁃cost detergent⁃like plant crude extracts for corrosion inhibition of various metals in aggressive acid environments.
文摘This paper proposes the application strategy of the intelligent technology in electronic engineering automation control. Artificial intelligence technology is about to realize the calculation of perception, reasoning and behavior study of it is different from most of the psychology, because it is more of an emphasis on the calculation, the artificial intelligence is also different from most of the computer science as because it is more of an emphasis on the perception, reasoning, and behavior, and future applications of artificial intelligence is beyond imagination. Regarding the multi-agent system target identification data fusion, the goal type is a proposition, each intelligent body gives through processing regarding the goal type judgment result is evidence, we discussed in detail of the essential applications on the item that will promote the further development.
文摘This paper discussed the application strategy of the computer network technology in the electronic information engineering. The use of computer network management technology, designed to maximize the effectiveness of computer network operations, while ensuring network management security. With the advent of the digital age, the computer network has been basically popular, so the computer network management technology research value and application value is more prominent become a digital information technology research one of the hot spots.. Good antivirus software can be easily installed in a few minutes to each NT server in the organization, and can be downloaded and distributed to all the target machine, set by the network administrator and management, it will work with the operating system and other security measures are tightly integrated to become part of the network security management, and automatically provide the best network virus defense measures. In the future, more integration of the methodologies will be considered and discussed.
基金supported by the Agricultural Science and Technology Innovation Program (ASTIP-IAS10).
文摘Glycine max L.accumulates a large amount of isoflavonoid compounds,which is beneficial for plant defense,plant-microbe symbiotic interactions,and human health.Several CYP450 subfamily genes are involved in the flavonoid biosynthetic pathway in plants.In the present study,we found 24 CYP82 subfamily genes were differentially expressed in various tissues of soybean,in Phytophthora sojae-infected soybean varieties and in soybean hairy roots treated with cell wall glucan elicitor.Six of them(GmCYP82A2,GmCYP82A3,GmCYP82A4,GmCYP82A23,GmCYP82C20 and GmCYP82D26)were co-expressed with other known isoflavonoid pathway genes in soybean.Their enzymatic activity in yeast feeding assays showed that only GmCYP82D26 was able to convert naringenin to daidzein with both aryl migration and dehydration function.When GmCYP82D26 was over-expressed in soybean hairy roots,the contents of the two major isoflavonoid aglycones in soybean(daidzein and genistein)were reduced,but total flavonoids were not affected.When GmCYP82D26 was suppressed by RNAi in the hairy roots,daidzein content was decreased but genistein content was increased,with unchanged total flavonoid content.GmCYP82D26 was found to be localized in the endoplasmic reticulum at subcellular level when transiently expressed in tobacco leaf epidermis.GmCYP82D26 gene was preferentially expressed in roots,with low expression level in other tissues in soybean.Homology modeling and molecular docking showed that GmCYP82D26 could form hydrogen bond with both HEM and naringenin at C5-OH and C4 carbonyl.All these results indicated that GmCYP82D26 possesses new and dual enzymatic activity,which bridges the two branches(daidzein and genistein branch)of isoflavonoid pathway in soybean.
基金financial support from National Basic Research Program of China (No.2014CB643304)the Key Technology of Corrosion Control on Wind Power Equipment Academician Workstation Project (No.2013B090400023)the National Natural Science Foundation of China (Grant No.51571202)
文摘The corrosion behavior of cupronickel alloy immersed in the simulated seawater in or without the presence of sulfate-reducing bacteria (SRB) was studied. The results of scanning electronic microscopy and electrochemical impedance spectra reveal that corrosion of the sample immersed in the simulated seawater with SRB was more serious than that immersed in the simulated seawater without SRB. The atomic force microscopy images show that after immersion for 15 days, the surface roughness of the sample in the simulated seawater with SRB was higher than that of the sample in the simulated seawater without SRB. The analysis of confocal laser scanning microscopy indicates that the average depth of the pits on the surface of the sample in the simulated seawater with SRB was almost twice deeper than that of the sample in the simulated seawater without SRB.
基金Acknowledgments The authors thank the editors and two anonymous referees for their helpful comments and suggestions that substantially improved the quality of this work. This research has been supported by grants from National Natural Science Foundation of China (71224001) and China Postdoctoral Science Foundation funded project (2015M571135).
文摘Data envelopment analysis (DEA) is an effective non-parametric method for measuring the relative efficiencies of decision making units (DMUs) with multiple inputs and outputs. In many real situations, the internal structure of DMUs is a two-stage network process with shared inputs used in both stages and common outputs produced by the both stages. For example, hospitals have a two-stage network structure. Stage 1 consumes resources such as information technology system, plant, equipment and admin personnel to generate outputs such as medical records, laundry and housekeeping. Stage 2 consumes the same set of resources used by stage 1 (named shared inputs) and the outputs generated by stage 1 (named intermediate measures) to provide patient services. Besides, some of outputs, for instance, patient satisfaction degrees, are generated by the two individual stages together (named shared outputs). Since some of shared inputs and outputs are hard split up and allocated to each individual stage, it needs to develop two-stage DEA methods for evaluating the performance of two-stage network processes in such problems. This paper extends the centralized model to measure the DEA efficiency of the two-stage process with non split-table shared inputs and outputs. A weighted additive approach is used to combine the two individual stages. Moreover, additive efficiency decomposition models are developed to simultaneously evaluate the maximal and the minimal achievable efficiencies for the individual stages. Finally, an example of 17 city branches of China Construction Bank in Anhui Province is employed to illustrate the proposed approach.