China is a country with a vast marine territory whose area covers one third of the total land territory area. With the exploitation of marine resources and the development of marine economy, marine economic regions ha...China is a country with a vast marine territory whose area covers one third of the total land territory area. With the exploitation of marine resources and the development of marine economy, marine economic regions have been formed gradually. We shouldn’t ignore them when we divide economic regions throughout the whole nation,especially in our country. In this paper, we’ll expand division principles, practice and methods of .marine comprehensive economic region. Liaoning Province,facing the Yellow Sea and the Bohai sea, is not only a part of Round-the-Bohai Sea Economic Region, but a part of national marine econemic region. Through evaluating marine resources of Liaoning, and analyzing development of marine economy, composition of marine industries and distributional characteristic of marine economy, Liaoning marine region is divided into Bohai Sea marine economic region and Yellow Sea marine economic region based on differences of marine economy. Thereby we go further into the formation of regional marine economic region and distributional mechanism of regional marine economy.展开更多
Background: The banning of fisheries discards by imposing an obligation to land unwanted catch constitutes a key point of the Common Fishery Policy reform proposed by the European Commission. The effect of such a ban ...Background: The banning of fisheries discards by imposing an obligation to land unwanted catch constitutes a key point of the Common Fishery Policy reform proposed by the European Commission. The effect of such a ban on discards on top marine predators such as seabirds is largely unknown, especially in oligotrophic systems of the Medi?terranean. The current study investigates the presence of scavenging seabirds around fishing trawlers as well as the exploitation of discards produced by bottom trawlers in the eastern Ionian Sea.Methods: On?board observations were randomly conducted in May and December 2014, in order to record the presence and use of fishery discards by two common seabird species, namely, Scopoli's Shearwater(Calonectris diomedea) and the Yellow?legged Gull(Larus michahellis).Results: A total of 3400 seabirds were counted during May of which 2190 individuals were Scopoli's Shearwaters and 1210 were Yellow?legged Gulls. The latter species was the only scavenger observed during winter and in total, 768 individuals were counted. Differences in species abundance in the study area are related to breeding phenology and migratory movements. The number of seabirds attending bottom trawler operations during morning and afternoon hours showed no significant differences for both seabird species. Both scavenging seabirds extensively exploited fishery discards, which were mainly demersal fish, and consumed 70–80% of the total fishery discards biomass; how?ever, they appeared to avoid poisonous species and/or large?sized fish. Yellow?legged Gulls displayed kleptoparasitic behaviour on Scopoli's Shearwater during feeding experiments. The number of such incidents depended on the number of gulls around the fishing vessel, with more than 90% success rates.Conclusions: Considering the average annual biomass of discards estimations and the consumption rate found in this work, 106.1–117.9 t may be offered as a food subsidy to scavenging seabirds in the study area and should support a substantial part of local populations. Our results constitute baseline information on the annual amount of fishery discards and their exploitation rate by seabirds in the Ionian Sea, and suggest further work for a complete understand?ing of the potential impacts of the discards reform bill on seabirds.展开更多
Based on catch and effort data of tuna longline fishery operating in the South Pacific Ocean, the South Pacific albacore stock was assessed by an improved Schaefer model. The results revealed that the intrinsic growth...Based on catch and effort data of tuna longline fishery operating in the South Pacific Ocean, the South Pacific albacore stock was assessed by an improved Schaefer model. The results revealed that the intrinsic growth rate was about 1.283 74 and carrying capacities vareied in the range from 73 734 to 266 732 metric tons. The growth ability of this species is remarkable. Stock dynamics mainly depends on environmental conditions. The stock is still in good condition. However, the continuous decreasing of biomass in recent years should be noticed.展开更多
Using the SeaBeam technology, the morphology of seamount and its relation to the formation of cobalt-rich crust in the central Pacific Ocean were surveyed during the cruise in 2003 for marine mineral resources. The re...Using the SeaBeam technology, the morphology of seamount and its relation to the formation of cobalt-rich crust in the central Pacific Ocean were surveyed during the cruise in 2003 for marine mineral resources. The result shows that seamounts can be divided morphologically into the spire seamount and the fiat topped seamount. These two types of seamount bear great differences in their landform, lithology and cobalt-rich crust. On the upper portion of the fiat topped seamount, the fiat top and the sharp escarpments are unfavorable to the growth of crust, and, consequently, the crusts here are mostly laminar or gravelly, their thicknesses generally show great variations, and the consecutive ore body often develops in its deep water region. On the spire topped seamount, however, the fiat area is small, and its gradient is constant without large variation from the top to the bottom. This favors the growth of cobalt-rich crust and often leads to consecutive tabular ore body of medium thickness, occurring on the spire topped seamount from the shallow water region to the deep water region. The cobalt-rich crust on the spire topped seamount is much better than that on the fiat topped seamount for the crust abundance, crust coverage and number of ore-occurrences within unit area. Furthermore, the crust on the spire topped seamount is rich in cobalt, nickel, manganese elements of high economic value. Because the crust with high quality ore often occurs in the shallow water region on the spire topped seamount, it can be mined and use more easily in the future.展开更多
Model output from a Pacific basin-wide three-dimensional physical-biogeochemical model during the period of 1991 to 2008 was used to investigate the impact of Kuroshio water on the source water of the southeastern Tai...Model output from a Pacific basin-wide three-dimensional physical-biogeochemical model during the period of 1991 to 2008 was used to investigate the impact of Kuroshio water on the source water of the southeastern Taiwan Strait. Based on the characteristic salinities of both Kuroshio water and the South China Sea water, a Kuroshio impact index (KII) was designed to measure the degree of impact. The KII correlates significantly with the northeast-southwest component of wind stress, but the former lags the latter by approximately two months. The correlation coefficient between them increases from 0.267 4 to 0.852 9, with a lag time increasing from 0 to 63 days. The impact of Kuroshio Water is greater in winter and spring than in summer and autumn. At the interannual time scale, E1 Nifio and La Nifia events play an important role in impacting the KII. During E1 Nifio events, more Kuroshio water contributes to the source water of the southeastern Taiwan Strait. Conversely, during La Nifia events, less Kuroshio water contributes to the source water.展开更多
Based on various patterns of groundwater and their abundance characters in south Liaodong Peninsula, the distribution, stage, pattern and characters of sea water intrusion in the serious sea water intrusion areas are ...Based on various patterns of groundwater and their abundance characters in south Liaodong Peninsula, the distribution, stage, pattern and characters of sea water intrusion in the serious sea water intrusion areas are analysed. The reasons to cause sea water intrusion are uneven precipitation, limited recharge of surface water, artificial overpumping, lithology and geological structure. It can provide scientific basis for reasonable utilization of limited water resource in line with the local conditions.展开更多
Short wave near-infrared(SWIR,900-1700 nm)fluorescence imaging has attracted extensive research interest from scientists due to its high imaging quality.However,the variety of SWIR fluorescence imaging agents are quit...Short wave near-infrared(SWIR,900-1700 nm)fluorescence imaging has attracted extensive research interest from scientists due to its high imaging quality.However,the variety of SWIR fluorescence imaging agents are quite limited and the corresponding quantum efficiency is rela-tively low.In this work,a novel conjugated polymer PDTSDTBT was reported,consisting of a donor unit with a tetrahedral Si(sp3)named DTS and an acceptor unit named DTBT with branched side chains.The design approach of endowing the donor-acceptor structure with the branched side chains successfully increase the fluorescence quantum efficiency.The polymer was prepared into nanoparticles by nanoprecipitation.The PDTSDTBT nanoparticles showed an absorption peak of 626 nm and fluorescence emission peak of 924 nm.The quantum efficiency of the nanoparticles is 0.53%,which is higher than that of nanotube fluorophores(0.4%).The nanoparticles also demonstrate a photothermal effect,the temperature of nanoparticles solution could reach 45℃under excitation by 660 nm laser.Therefore,the PDTSDTBT nanoparticles is an excellent fluorescent imaging agent with potential photothermal applications.展开更多
Two new complexes, [Cu(DMB)2(NAA)2](1) and [Co(DMB)2(NAA)2](2)(DMB = 5,6-dimethylbenzimidazole, HNNA = 1-naphthylacetic acid), were hydrothermally synthesized and characterized by elemental analysis, IR ...Two new complexes, [Cu(DMB)2(NAA)2](1) and [Co(DMB)2(NAA)2](2)(DMB = 5,6-dimethylbenzimidazole, HNNA = 1-naphthylacetic acid), were hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, TGA, PXRD and single-crystal X-ray diffraction analysis. The coordination geometry of the metal centers is a perfect square plane for 1 and a distorted tetrahedron for 2. In compound 1, the mononuclear units are linked by N–H···O hydrogen bonds to form a 1D chain structure, while mononuclear motifs of 2 are extended via N–H···O hydrogen bonding and π-π stacking interactions into a 2D supramolecular layer. The remarkable catalytic properties of the two complexes for the degradation of Congo red dye have been found.展开更多
An internal gravity wave model was employed to simulate the generation of internal solitary waves(ISWs)over a sill by tidal flows.A westward shoaling pycnocline parameterization scheme derived from a three-parameter m...An internal gravity wave model was employed to simulate the generation of internal solitary waves(ISWs)over a sill by tidal flows.A westward shoaling pycnocline parameterization scheme derived from a three-parameter model was adopted,and then 14 numerical experiments were designed to investigate the influence of the pycnocline thickness,density difference across the pycnocline,westward shoaling isopycnal slope angle and pycnocline depth on the ISWs.When the pycnocline thickness on both sides of the sill increases,the total barotropic kinetic energy,total baroclinic energy and ratio of baroclinic kinetic energy(KE)to available potential energy(APE)decrease,whilst the depth of isopycnal undergoing maximum displacement and ratio of baroclinic energy to barotropic energy increase.When the density difference on both sides of the sill decreases synchronously,the total barotropic kinetic energy,ratio of baroclinic energy to barotropic energy and total baroclinic energy decrease,whilst the depth of isopycnal undergoing maximum displacement increases.When the westward shoaling isopycnal slope angle increases,the total baroclinic energy increases whilst the depth of turning point almost remains unchanged.When the depth of westward shoaling pycnocline on both sides of the sill reduces,the ratio of baroclinic energy to barotropic energy and total baroclinic energy decrease,whilst the total barotropic kinetic energy and ratio of KE to APE increase.When one of the above four different influencing factors was increased by 10%while the other factors keep unchanged,the amplitude of the leading soliton in ISW Packet A was decreased by 2.80%,7.47%,3.21%and 6.42%respectively.The density difference across the pycnocline and the pycnocline depth are the two most important factors in affecting the characteristics and energetics of ISWs.展开更多
Global change determines the environmental condition and leads to decide the carrying capacity. While carrying capacity determines the extinction of the species, it is an important issue to estimate the extinction poi...Global change determines the environmental condition and leads to decide the carrying capacity. While carrying capacity determines the extinction of the species, it is an important issue to estimate the extinction point of the species, the minimal carrying capacity, or the tolerant limitation of the species. If it is possible to estimate the tolerant limitation of the species, it will be possible to control the global change. Applied the above idea to the albacore stocks, it revealed that extinction point was about 0.0018% of the present status. From these results, it implies that this method may also suitable to other species for estimating their carrying capacities.展开更多
Using isotopic techniques to investigate hydrogeologic properties of aquifers and springs is a common approach nowadays that overcomes problems of monitoring classical hydrogeologic parameters such as piezometric leve...Using isotopic techniques to investigate hydrogeologic properties of aquifers and springs is a common approach nowadays that overcomes problems of monitoring classical hydrogeologic parameters such as piezometric levels and groundwater flow velocities. Nevertheless, interpretation of the results and maintenance of long term isotopic monitoring are also difficult and resource consuming tasks. In the present study the isotopic composition of springs and rain water has been examined in various sampling sites of Western Crete in order to identify spring-aquifer interactions and propose appropriate management and restoration measures. The output of this effort illustrated 4 main groups of springs sharing common isotopic characteristics and recharge zones. These potential recharge areas for each group have been delineated by combining the isotopic and geological properties of the entire area with the contribution of GIS techniques.展开更多
A volume-amending method is developed both to keep the level set function as an algebraic distance function and to preserve the bubble mass in a level set approach for incompressible two-phase flows with the significa...A volume-amending method is developed both to keep the level set function as an algebraic distance function and to preserve the bubble mass in a level set approach for incompressible two-phase flows with the significantly deformed free interface. After the traditional reinitialization procedure, a vol-ume-amending method is added for correcting the position of the interface according to mass loss/gain error until the mass error falls in the allowable range designated in advance. The level set approach with this volume-amending method incorporated has been validated by three test cases: the motion of a single axisymmetrical bubble or drop in liquid, the motion of a two-dimensional water drop falling through the air into a water pool, and the interactional motion of two buoyancy-driven three- dimensional deformable bubbles. The computational results with this volume-amending method in-corporated are in good agreement with the reported experimental data and the mass is well preserved in all cases.展开更多
When calculating the sampled-date representation of nonlinear systems second-order hold(SOH) assumption can be applied to improving the precision of the discretization results. This paper proposes a discretization met...When calculating the sampled-date representation of nonlinear systems second-order hold(SOH) assumption can be applied to improving the precision of the discretization results. This paper proposes a discretization method based on Taylor series and the SOH assumption for the nonlinear systems with the time delayed non-affine input. The mathematical structure of the proposed discretization method is explored. This proposed discretization method can provide a precise and finite dimensional discretization model for the nonlinear time-delayed non-affine system by keeping the truncation order of the Taylor series. The performance of the proposed discretization method is evaluated by doing the simulation using a nonlinear system with the time-delayed non-affine input.Different input signals, time-delay values and sampling periods are considered in the simulation to investigate the proposed method.The simulation results demonstrate that the proposed method is practical and easy for time-delayed nonlinear non-affine systems.The comparison between SOH assumption with first-order hold(FOH) and zero-order hold(ZOH) assumptions is given to show the advantages of the proposed method.展开更多
Crete with its complex geomorphological history is the island with the highest number of endemism observed in animal and plant taxa throughout the Aegean archipelago.While other groups of organisms within Crete are we...Crete with its complex geomorphological history is the island with the highest number of endemism observed in animal and plant taxa throughout the Aegean archipelago.While other groups of organisms within Crete are well-studied,the freshwater gastropod fauna still remains poorly investigated.Bythinella and Pseudamnicola,are 2 genera of freshwater springsnails,both present on the island,inhabiting springs and other freshwater habitats.Here,we conduct a comprehensive study on the distribution of the different genetic lineages of the 2 gastropod genera in order to assess the mode of their differentiation on the island and infer the actual number of species present in the island.Towards these aims,sequence data from the mitochondrial gene were used and analyzed within a phylogenetic framework.For Bythinella,our results strongly support at least 5 delineated Bythinella spp.inhabiting Crete,which correspond to the already described species from previous studies with the addition of a new one.Bythinella analyses reveal an old time-frame of differentiation with vicariant phenomena being more likely the main drivers shaping the present-day distribution of the genus’genetic lineages.For Pseudamnicola,our data indicate the presence of at least 2 delineated Pseudamnicola spp.with a differentiation more consistent to an isolation-by-distance pattern of a relatively recent origin.Dispersion processes followed by isolation of the populations and/or recent speciation,seem to be the underlying process for the current distribution of Pseudamnicola lineages.展开更多
Aeromonas sobria,a Gram-negative bacterium that can colonize both humans and animals,is found in a variety of environments,including water,seafood,meat,and vegetables(Cahill,1990;Galindo et al.,2004;Song et al,2019).A...Aeromonas sobria,a Gram-negative bacterium that can colonize both humans and animals,is found in a variety of environments,including water,seafood,meat,and vegetables(Cahill,1990;Galindo et al.,2004;Song et al,2019).Aeromonas spp.are conditionally pathogenic bacteria in aquaculture,which can rapidly proliferate,causing disease and even death in fish,especially when the environment is degraded(Neamat-Allah et al,2020,2021a,2021b).In developing countries,Aeromonas spp.have been associated with a wide spectrum of infections in humans,including gastroen-teritis,wound infections,septicemia,and lung infections(San Joaquin and Pickett,1988;Wang et al,2009;Su et al,2013).Infections caused by Aeromonas spp.are usually more severe in immunocompromised individuals(Miyamoto et al,2017).展开更多
基金Subsidized by the National Natural Science Foundation of China(49671022).
文摘China is a country with a vast marine territory whose area covers one third of the total land territory area. With the exploitation of marine resources and the development of marine economy, marine economic regions have been formed gradually. We shouldn’t ignore them when we divide economic regions throughout the whole nation,especially in our country. In this paper, we’ll expand division principles, practice and methods of .marine comprehensive economic region. Liaoning Province,facing the Yellow Sea and the Bohai sea, is not only a part of Round-the-Bohai Sea Economic Region, but a part of national marine econemic region. Through evaluating marine resources of Liaoning, and analyzing development of marine economy, composition of marine industries and distributional characteristic of marine economy, Liaoning marine region is divided into Bohai Sea marine economic region and Yellow Sea marine economic region based on differences of marine economy. Thereby we go further into the formation of regional marine economic region and distributional mechanism of regional marine economy.
基金performed within the framework of the ECODISC project,entitled“ECOsystem effect of fisheries DISCards”,partially funded by the NSRF 2007-2013 Operational Programme“Education and Lifelong Learning”,which is cofinanced by Greece and the European UnionFisheries data were collected within the framework of the 2014 Greek National Fisheries Data Collection Programme(EPSAD)funded by the Greek Government and the European Union under Regulation 199/2008/EU
文摘Background: The banning of fisheries discards by imposing an obligation to land unwanted catch constitutes a key point of the Common Fishery Policy reform proposed by the European Commission. The effect of such a ban on discards on top marine predators such as seabirds is largely unknown, especially in oligotrophic systems of the Medi?terranean. The current study investigates the presence of scavenging seabirds around fishing trawlers as well as the exploitation of discards produced by bottom trawlers in the eastern Ionian Sea.Methods: On?board observations were randomly conducted in May and December 2014, in order to record the presence and use of fishery discards by two common seabird species, namely, Scopoli's Shearwater(Calonectris diomedea) and the Yellow?legged Gull(Larus michahellis).Results: A total of 3400 seabirds were counted during May of which 2190 individuals were Scopoli's Shearwaters and 1210 were Yellow?legged Gulls. The latter species was the only scavenger observed during winter and in total, 768 individuals were counted. Differences in species abundance in the study area are related to breeding phenology and migratory movements. The number of seabirds attending bottom trawler operations during morning and afternoon hours showed no significant differences for both seabird species. Both scavenging seabirds extensively exploited fishery discards, which were mainly demersal fish, and consumed 70–80% of the total fishery discards biomass; how?ever, they appeared to avoid poisonous species and/or large?sized fish. Yellow?legged Gulls displayed kleptoparasitic behaviour on Scopoli's Shearwater during feeding experiments. The number of such incidents depended on the number of gulls around the fishing vessel, with more than 90% success rates.Conclusions: Considering the average annual biomass of discards estimations and the consumption rate found in this work, 106.1–117.9 t may be offered as a food subsidy to scavenging seabirds in the study area and should support a substantial part of local populations. Our results constitute baseline information on the annual amount of fishery discards and their exploitation rate by seabirds in the Ionian Sea, and suggest further work for a complete understand?ing of the potential impacts of the discards reform bill on seabirds.
文摘Based on catch and effort data of tuna longline fishery operating in the South Pacific Ocean, the South Pacific albacore stock was assessed by an improved Schaefer model. The results revealed that the intrinsic growth rate was about 1.283 74 and carrying capacities vareied in the range from 73 734 to 266 732 metric tons. The growth ability of this species is remarkable. Stock dynamics mainly depends on environmental conditions. The stock is still in good condition. However, the continuous decreasing of biomass in recent years should be noticed.
文摘Using the SeaBeam technology, the morphology of seamount and its relation to the formation of cobalt-rich crust in the central Pacific Ocean were surveyed during the cruise in 2003 for marine mineral resources. The result shows that seamounts can be divided morphologically into the spire seamount and the fiat topped seamount. These two types of seamount bear great differences in their landform, lithology and cobalt-rich crust. On the upper portion of the fiat topped seamount, the fiat top and the sharp escarpments are unfavorable to the growth of crust, and, consequently, the crusts here are mostly laminar or gravelly, their thicknesses generally show great variations, and the consecutive ore body often develops in its deep water region. On the spire topped seamount, however, the fiat area is small, and its gradient is constant without large variation from the top to the bottom. This favors the growth of cobalt-rich crust and often leads to consecutive tabular ore body of medium thickness, occurring on the spire topped seamount from the shallow water region to the deep water region. The cobalt-rich crust on the spire topped seamount is much better than that on the fiat topped seamount for the crust abundance, crust coverage and number of ore-occurrences within unit area. Furthermore, the crust on the spire topped seamount is rich in cobalt, nickel, manganese elements of high economic value. Because the crust with high quality ore often occurs in the shallow water region on the spire topped seamount, it can be mined and use more easily in the future.
基金The National Natural Science Foundation of China under contract Nos 41076002 and 41276007the Fundamental Research Funds for the Central Universities under contract Nos 2010121036 and 2013121047the Joint Fund Program for Promoting Science & Technology Cooperation across the Taiwan Strait supported by the National Natural Science Foundation of China and Fujian Province under contract No.U1305231
文摘Model output from a Pacific basin-wide three-dimensional physical-biogeochemical model during the period of 1991 to 2008 was used to investigate the impact of Kuroshio water on the source water of the southeastern Taiwan Strait. Based on the characteristic salinities of both Kuroshio water and the South China Sea water, a Kuroshio impact index (KII) was designed to measure the degree of impact. The KII correlates significantly with the northeast-southwest component of wind stress, but the former lags the latter by approximately two months. The correlation coefficient between them increases from 0.267 4 to 0.852 9, with a lag time increasing from 0 to 63 days. The impact of Kuroshio Water is greater in winter and spring than in summer and autumn. At the interannual time scale, E1 Nifio and La Nifia events play an important role in impacting the KII. During E1 Nifio events, more Kuroshio water contributes to the source water of the southeastern Taiwan Strait. Conversely, during La Nifia events, less Kuroshio water contributes to the source water.
文摘Based on various patterns of groundwater and their abundance characters in south Liaodong Peninsula, the distribution, stage, pattern and characters of sea water intrusion in the serious sea water intrusion areas are analysed. The reasons to cause sea water intrusion are uneven precipitation, limited recharge of surface water, artificial overpumping, lithology and geological structure. It can provide scientific basis for reasonable utilization of limited water resource in line with the local conditions.
基金supported by the National Natural Science Foundation of China(21807062,21976099 and 31570355)the Shandong Provincial Natural Science Foundation(ZR2018BB014)+2 种基金the Source Innovation Project of Qingdao(171183jch)Qingdao Postdoctoral Applied Research Project(2018111)National College Students Innova-tion and Entrepreneurship Training Program(201910429007)
文摘Short wave near-infrared(SWIR,900-1700 nm)fluorescence imaging has attracted extensive research interest from scientists due to its high imaging quality.However,the variety of SWIR fluorescence imaging agents are quite limited and the corresponding quantum efficiency is rela-tively low.In this work,a novel conjugated polymer PDTSDTBT was reported,consisting of a donor unit with a tetrahedral Si(sp3)named DTS and an acceptor unit named DTBT with branched side chains.The design approach of endowing the donor-acceptor structure with the branched side chains successfully increase the fluorescence quantum efficiency.The polymer was prepared into nanoparticles by nanoprecipitation.The PDTSDTBT nanoparticles showed an absorption peak of 626 nm and fluorescence emission peak of 924 nm.The quantum efficiency of the nanoparticles is 0.53%,which is higher than that of nanotube fluorophores(0.4%).The nanoparticles also demonstrate a photothermal effect,the temperature of nanoparticles solution could reach 45℃under excitation by 660 nm laser.Therefore,the PDTSDTBT nanoparticles is an excellent fluorescent imaging agent with potential photothermal applications.
基金Supported by Jiangsu province of academic scientific research industrialization projects(JHB2011-60)Public Science and Technology Research Funds Projects of Ocean"(201305007)Lianyungang Science and technology project(CG1110)
文摘Two new complexes, [Cu(DMB)2(NAA)2](1) and [Co(DMB)2(NAA)2](2)(DMB = 5,6-dimethylbenzimidazole, HNNA = 1-naphthylacetic acid), were hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, TGA, PXRD and single-crystal X-ray diffraction analysis. The coordination geometry of the metal centers is a perfect square plane for 1 and a distorted tetrahedron for 2. In compound 1, the mononuclear units are linked by N–H···O hydrogen bonds to form a 1D chain structure, while mononuclear motifs of 2 are extended via N–H···O hydrogen bonding and π-π stacking interactions into a 2D supramolecular layer. The remarkable catalytic properties of the two complexes for the degradation of Congo red dye have been found.
基金The Key Research Program of Frontier SciencesChinese Academy of Sciences(CAS)under contract No.QYZDJSSW-DQC034+6 种基金the Talent Project from Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract No.GML2019ZD0304the National Natural Science Foundation of China(NSFC)under contract Nos 41521005 and 62071207the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Natural Science Foundation of Huai Hai Institute of Technology under contract No.Z2017006the Project from Department of Natural Resources of Guangdong Province under contract No.(2020)017the Open Project of State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanolog,CAS under contract No.LTO1702Postgraduate Research&Practice Innovation Program of Jiangsu Province under contract No.SJCX190963。
文摘An internal gravity wave model was employed to simulate the generation of internal solitary waves(ISWs)over a sill by tidal flows.A westward shoaling pycnocline parameterization scheme derived from a three-parameter model was adopted,and then 14 numerical experiments were designed to investigate the influence of the pycnocline thickness,density difference across the pycnocline,westward shoaling isopycnal slope angle and pycnocline depth on the ISWs.When the pycnocline thickness on both sides of the sill increases,the total barotropic kinetic energy,total baroclinic energy and ratio of baroclinic kinetic energy(KE)to available potential energy(APE)decrease,whilst the depth of isopycnal undergoing maximum displacement and ratio of baroclinic energy to barotropic energy increase.When the density difference on both sides of the sill decreases synchronously,the total barotropic kinetic energy,ratio of baroclinic energy to barotropic energy and total baroclinic energy decrease,whilst the depth of isopycnal undergoing maximum displacement increases.When the westward shoaling isopycnal slope angle increases,the total baroclinic energy increases whilst the depth of turning point almost remains unchanged.When the depth of westward shoaling pycnocline on both sides of the sill reduces,the ratio of baroclinic energy to barotropic energy and total baroclinic energy decrease,whilst the total barotropic kinetic energy and ratio of KE to APE increase.When one of the above four different influencing factors was increased by 10%while the other factors keep unchanged,the amplitude of the leading soliton in ISW Packet A was decreased by 2.80%,7.47%,3.21%and 6.42%respectively.The density difference across the pycnocline and the pycnocline depth are the two most important factors in affecting the characteristics and energetics of ISWs.
文摘Global change determines the environmental condition and leads to decide the carrying capacity. While carrying capacity determines the extinction of the species, it is an important issue to estimate the extinction point of the species, the minimal carrying capacity, or the tolerant limitation of the species. If it is possible to estimate the tolerant limitation of the species, it will be possible to control the global change. Applied the above idea to the albacore stocks, it revealed that extinction point was about 0.0018% of the present status. From these results, it implies that this method may also suitable to other species for estimating their carrying capacities.
文摘Using isotopic techniques to investigate hydrogeologic properties of aquifers and springs is a common approach nowadays that overcomes problems of monitoring classical hydrogeologic parameters such as piezometric levels and groundwater flow velocities. Nevertheless, interpretation of the results and maintenance of long term isotopic monitoring are also difficult and resource consuming tasks. In the present study the isotopic composition of springs and rain water has been examined in various sampling sites of Western Crete in order to identify spring-aquifer interactions and propose appropriate management and restoration measures. The output of this effort illustrated 4 main groups of springs sharing common isotopic characteristics and recharge zones. These potential recharge areas for each group have been delineated by combining the isotopic and geological properties of the entire area with the contribution of GIS techniques.
基金the National Natural Science Foundation of China (Grant Nos. 20490206, 50404009, 20576133 & 20676134)PetroChina,and the National Basic Research Priorities Program (Grant Nos. 2004CB217604, 2007CB613507)
文摘A volume-amending method is developed both to keep the level set function as an algebraic distance function and to preserve the bubble mass in a level set approach for incompressible two-phase flows with the significantly deformed free interface. After the traditional reinitialization procedure, a vol-ume-amending method is added for correcting the position of the interface according to mass loss/gain error until the mass error falls in the allowable range designated in advance. The level set approach with this volume-amending method incorporated has been validated by three test cases: the motion of a single axisymmetrical bubble or drop in liquid, the motion of a two-dimensional water drop falling through the air into a water pool, and the interactional motion of two buoyancy-driven three- dimensional deformable bubbles. The computational results with this volume-amending method in-corporated are in good agreement with the reported experimental data and the mass is well preserved in all cases.
基金supported by Jiangsu Province University Natural Science Research Project(No.13KJB510003)Jiangsu Province Research and Development Institute of Marine Resources Science and Technology Open Fund Project(No.JSIMR11B05)
文摘When calculating the sampled-date representation of nonlinear systems second-order hold(SOH) assumption can be applied to improving the precision of the discretization results. This paper proposes a discretization method based on Taylor series and the SOH assumption for the nonlinear systems with the time delayed non-affine input. The mathematical structure of the proposed discretization method is explored. This proposed discretization method can provide a precise and finite dimensional discretization model for the nonlinear time-delayed non-affine system by keeping the truncation order of the Taylor series. The performance of the proposed discretization method is evaluated by doing the simulation using a nonlinear system with the time-delayed non-affine input.Different input signals, time-delay values and sampling periods are considered in the simulation to investigate the proposed method.The simulation results demonstrate that the proposed method is practical and easy for time-delayed nonlinear non-affine systems.The comparison between SOH assumption with first-order hold(FOH) and zero-order hold(ZOH) assumptions is given to show the advantages of the proposed method.
文摘Crete with its complex geomorphological history is the island with the highest number of endemism observed in animal and plant taxa throughout the Aegean archipelago.While other groups of organisms within Crete are well-studied,the freshwater gastropod fauna still remains poorly investigated.Bythinella and Pseudamnicola,are 2 genera of freshwater springsnails,both present on the island,inhabiting springs and other freshwater habitats.Here,we conduct a comprehensive study on the distribution of the different genetic lineages of the 2 gastropod genera in order to assess the mode of their differentiation on the island and infer the actual number of species present in the island.Towards these aims,sequence data from the mitochondrial gene were used and analyzed within a phylogenetic framework.For Bythinella,our results strongly support at least 5 delineated Bythinella spp.inhabiting Crete,which correspond to the already described species from previous studies with the addition of a new one.Bythinella analyses reveal an old time-frame of differentiation with vicariant phenomena being more likely the main drivers shaping the present-day distribution of the genus’genetic lineages.For Pseudamnicola,our data indicate the presence of at least 2 delineated Pseudamnicola spp.with a differentiation more consistent to an isolation-by-distance pattern of a relatively recent origin.Dispersion processes followed by isolation of the populations and/or recent speciation,seem to be the underlying process for the current distribution of Pseudamnicola lineages.
文摘Aeromonas sobria,a Gram-negative bacterium that can colonize both humans and animals,is found in a variety of environments,including water,seafood,meat,and vegetables(Cahill,1990;Galindo et al.,2004;Song et al,2019).Aeromonas spp.are conditionally pathogenic bacteria in aquaculture,which can rapidly proliferate,causing disease and even death in fish,especially when the environment is degraded(Neamat-Allah et al,2020,2021a,2021b).In developing countries,Aeromonas spp.have been associated with a wide spectrum of infections in humans,including gastroen-teritis,wound infections,septicemia,and lung infections(San Joaquin and Pickett,1988;Wang et al,2009;Su et al,2013).Infections caused by Aeromonas spp.are usually more severe in immunocompromised individuals(Miyamoto et al,2017).