Two new species of free-living marine nematode from mangrove habitats in Xiamen Bay are identified.Anoplostoma tumidum sp.nov.is characterized by relatively short outer labial setae(0.86–1.00 h.d.),long tail(c 7.2–8...Two new species of free-living marine nematode from mangrove habitats in Xiamen Bay are identified.Anoplostoma tumidum sp.nov.is characterized by relatively short outer labial setae(0.86–1.00 h.d.),long tail(c 7.2–8.9,c' 8.3–10.5),an instinct swollen distal portion of slender spicule(Sc 94–101 μm),and well developed copulatory bursae without bursal papillae.A.tumidum sp.nov.differs from all valid species of genus Anoplostoma in copulatory apparatus of males with a distinct swollen distal portion of spicule,and a relatively obvious constriction of head.A.paraviviparum sp.nov.is characterized by relatively long outer labial setae(1.11–1.22 h.d.),and tail(c 6.6–8.5,c' 8.6–10.2);elongated spicules with distinct knob-like proximal and pointed distal ends(Sc 46–69 μm);distinct strip-like gubernaculum(length with 11–15μm);well developed copulatory bursae with precloacal papillae and post-cloacal papillae;and a distinct constriction of head.A.paraviviparum sp.nov.is similar to A.viviparum Bastian,1865,but differs in the reproductive mode of female and the constriction of head.展开更多
A new species of free-living marine nematode is described from intertidal sediment of the East China Sea.The new species belongs to the Oncholaimidae family.Oncholaimus zhangi sp.nov.is characterized by males having a...A new species of free-living marine nematode is described from intertidal sediment of the East China Sea.The new species belongs to the Oncholaimidae family.Oncholaimus zhangi sp.nov.is characterized by males having a large ventral swelling situated just posterior to the middle of the tail,no precloacal papilla,and a row of 6–7 ventral genital setae.The tails of both males and females are similar,being conico-cylindrical in shape.The new species is distinguished from other closely related species by the presence of a prominent ventral swelling at the tail of males and a similar tail shape in both sexes.About 110valid species in this genus have been recorded to date.展开更多
We investigated the diversity and structure of free-living marine nematode communities at three sandy beaches representing typical intertidal environments of a temperate zone in Qingdao,Shandong Province,China.Average...We investigated the diversity and structure of free-living marine nematode communities at three sandy beaches representing typical intertidal environments of a temperate zone in Qingdao,Shandong Province,China.Average nematode abundance ranged from 1006 to 2170 ind.10 cm-2,and a total of 34 nematode genera were recorded,of which only 8 were common in all the studied beaches.Pielou's evenness and Shannon-Wiener diversity index were the lowest at the second beach where nematode abundance was the highest.The highest species diversity index coincided with the lowest nematode abundance at Shilaoren beach.Sediment median grain size,sorting coefficient,and chlorophyll-a content were essential for differentiation in nematode abundance and species diversity,whereas taxonomic diversity of nematode was homogeneous across the three beaches.In 0–20 cm sediment profile,nematode abundance declined abruptly with depth,whereas nematode diversity changed gently with obvious difference in 16–20 cm layer.Sediment granulometry and chlorophyll-a content were the two foremost factors which influenced the vertical distribution pattern of nematode generic diversity.Non-selective deposit feeders constituted the most dominant trophic group,followed by epistratum feeders.Bathylaimus(family:Tripyloididae) dominated at the second and Yangkou beach,while Theristus(family:Xyalidae) prevailed at Shilaoren beach.Omnivores and predators became important at Shilaoren beach because of the high proportion of Enoplolaimus.Even though,nematode community of the studied beaches did not differ significantly from each other.展开更多
Response spectra of fixed offshore structures impacted by extreme waves are investigated based on the higher order components of the nonlinear drag force. In this way, steel jacket platforms are simplified as a mass a...Response spectra of fixed offshore structures impacted by extreme waves are investigated based on the higher order components of the nonlinear drag force. In this way, steel jacket platforms are simplified as a mass attached to a light cantilever cylinder and their corresponding deformation response spectra are estimated by utilizing a generalized single degree of freedom system. Based on the wave data recorded in the Persian Gulf region, extreme wave loading conditions corresponding to different return periods are exerted on the offshore structures. Accordingly, the effect of the higher order components of the drag force is considered and compared to the linearized state for different sea surface levels. When the fundamental period of the offshore structure is about one third of the main period of wave loading, the results indicate the linearized drag term is not capable of achieving a reliable deformation response spectrum.展开更多
In considering the vertical heat boundary approximation for the free surface applied. However, due to the existence of the transport problems in the upper ocean, the flat upper and the horizontal homogenous hypothesis...In considering the vertical heat boundary approximation for the free surface applied. However, due to the existence of the transport problems in the upper ocean, the flat upper and the horizontal homogenous hypothesis are usually wave motion, the application of this approximation may result in some errors to the solar irradiation since it decays quickly in respect to the actual thickness of the water layer below the surface; on the other hand, due to the fluctuation of the water layer depth, it is improper to neglect the effects of the horizontal advection and turbulent diffusion since they also contribute to the vertical heat transport. A new model is constructed in this study to reflect these effects. The corresponding numerical simulations show that the wave motion may remarkably accelerate the vertical heat transferring process and the variation of the temperature in the wave affected layer appears in an oscillating manner.展开更多
The ‘Freedom of Navigation' issue has been volatile and often influenced by Sino-US relations in recent years. This problem was rooted in different interpretation of the UNCLOS by China and the US. It has also re...The ‘Freedom of Navigation' issue has been volatile and often influenced by Sino-US relations in recent years. This problem was rooted in different interpretation of the UNCLOS by China and the US. It has also reflected their different national Interests and maritime strategies. This issue has caused frequent frictions between the two sides and may lead to their future contest for sea power. At the same time, it also urges the both sides to set up new mechanism for confidence building that may help them to manage it in a more rational way.展开更多
The three water-soluble polysaccharides (PI, PII and Pill), the ethyl acetate extraction (EA) and its five fractions of petroleum ether (PeF), ethyl acetate (EaF), butanol (BuF), methanol (MeF) and water ...The three water-soluble polysaccharides (PI, PII and Pill), the ethyl acetate extraction (EA) and its five fractions of petroleum ether (PeF), ethyl acetate (EaF), butanol (BuF), methanol (MeF) and water (WtF) from marine agrobacterium 1202 were prepared and then subjected to antioxidant activity evaluation. The antioxidant activity was tested using the 1, 1-Diphenyl-2-picryl-hydrazyl (DPPH) free radical-scavenging assay, the hydrogen peroxide-induced luminot chemiluminescence (CL) assay and hydroxyl free radical-initiated chemiluminescence (CL) assay. All the fractions exerted significant inhibitory effects on hydrogen peroxide and hydroxyl free radical. The extracts of EA, EaF and BuF could also showed inhibition on DPPH. Among of them, the extracts of EaF showed full of antioxidant activity on the three tested system. The result suggested that the marine agrobacterium 1202 is a potential source of natural antioxidantagent.展开更多
Biodiversity pattems of free-living marine nematodes were studied using specific, taxonomic and phylogenetic diversity measures in the southern Yellow Sea, China. The results showed that the average of Shannon-Wiener ...Biodiversity pattems of free-living marine nematodes were studied using specific, taxonomic and phylogenetic diversity measures in the southern Yellow Sea, China. The results showed that the average of Shannon-Wiener diversity index (H') in the study area was 3.17. The higher values were distributed in the east part of Shandong coastal waters and north part of Jiangsu coastal waters, while the lower values were distributed in the southern Yellow Sea Cold Water Mass (YSCWM). The average of taxonomic diversity (A) was 62.09 in the study region. The higher values were distributed in the transitional areas between the coastal areas and the southem YSCWM, while the lower values were distributed near the north part of Jiangsu coastal waters and the YSCWM. Results of correlation analysis of species diversity and taxonomic diversity showed that some of the two kinds of diversity index were inde- pendent, which suggested that combining the two kinds of diversity indices can reflect the ecological characteristics better. A test for 95% probability funnels of average taxonomic distinctness and variation in taxonomic distinctness suggested that Station 8794 (in the YSCWM) was outside of the 95% probability funnels, which may be due to the environmental stress. Results of correlation analysis between marine nematodes biodiversity and environmental variables showed that the sediment characteristics (Mdo and Silt-clay fraction) and phaeophorbide a (Pha-a) were the most important factors to determine the biodiversity patterns of marine nematodes.展开更多
The ratio between the reactivity of HC and NOx, i.e., φ = ∑kOH+HC, [HCi] / (kOH+No[NO] + kOH+NO2 [NO2]), is used to study the chemistry of HOx radicals (HOE and OH) in the marine boundary layer (MBL). Data...The ratio between the reactivity of HC and NOx, i.e., φ = ∑kOH+HC, [HCi] / (kOH+No[NO] + kOH+NO2 [NO2]), is used to study the chemistry of HOx radicals (HOE and OH) in the marine boundary layer (MBL). Data analysis shows that HOx production and OH/HO2 ratio strongly depend on φ. The OH radical concentration presents an ascending tendency in low φ region but a de- clining one in high ∞ region, while HO2 radical increases with increasing φ under low φ conditions but appears to be nearly constant with the variation of ∞ under high φ conditions. The observed OH/HO2 ratio shows a continuous decrease with the increase of φ. Model studies are conducted to illuminate the behavior of HOx radicals in different φ regions, and the results represent general agreement with the observed variations of HOx radicals and can well explain the observed behavior of HOx radicals. This study demonstrates that φ could be used as an efficient parameter to ascertain the behavior of HOx radicals in the clean marine boundary layer.展开更多
基金supported by the National Natural Science Foundation of China (No.41176107)Open Research Fund Program of Provincial Key Laboratory of Marine Fishery Resources and Eco-environment of Fujian (No.fmfre2014012)the Training Program of Fujian Excellent Talents in University
文摘Two new species of free-living marine nematode from mangrove habitats in Xiamen Bay are identified.Anoplostoma tumidum sp.nov.is characterized by relatively short outer labial setae(0.86–1.00 h.d.),long tail(c 7.2–8.9,c' 8.3–10.5),an instinct swollen distal portion of slender spicule(Sc 94–101 μm),and well developed copulatory bursae without bursal papillae.A.tumidum sp.nov.differs from all valid species of genus Anoplostoma in copulatory apparatus of males with a distinct swollen distal portion of spicule,and a relatively obvious constriction of head.A.paraviviparum sp.nov.is characterized by relatively long outer labial setae(1.11–1.22 h.d.),and tail(c 6.6–8.5,c' 8.6–10.2);elongated spicules with distinct knob-like proximal and pointed distal ends(Sc 46–69 μm);distinct strip-like gubernaculum(length with 11–15μm);well developed copulatory bursae with precloacal papillae and post-cloacal papillae;and a distinct constriction of head.A.paraviviparum sp.nov.is similar to A.viviparum Bastian,1865,but differs in the reproductive mode of female and the constriction of head.
基金Supported by the National Natural Science Foundation of China(No.41176107)
文摘A new species of free-living marine nematode is described from intertidal sediment of the East China Sea.The new species belongs to the Oncholaimidae family.Oncholaimus zhangi sp.nov.is characterized by males having a large ventral swelling situated just posterior to the middle of the tail,no precloacal papilla,and a row of 6–7 ventral genital setae.The tails of both males and females are similar,being conico-cylindrical in shape.The new species is distinguished from other closely related species by the presence of a prominent ventral swelling at the tail of males and a similar tail shape in both sexes.About 110valid species in this genus have been recorded to date.
基金supported by the National Natural Science Foundation of China (Nos.40906063,41106122,40730847,and 41576153)
文摘We investigated the diversity and structure of free-living marine nematode communities at three sandy beaches representing typical intertidal environments of a temperate zone in Qingdao,Shandong Province,China.Average nematode abundance ranged from 1006 to 2170 ind.10 cm-2,and a total of 34 nematode genera were recorded,of which only 8 were common in all the studied beaches.Pielou's evenness and Shannon-Wiener diversity index were the lowest at the second beach where nematode abundance was the highest.The highest species diversity index coincided with the lowest nematode abundance at Shilaoren beach.Sediment median grain size,sorting coefficient,and chlorophyll-a content were essential for differentiation in nematode abundance and species diversity,whereas taxonomic diversity of nematode was homogeneous across the three beaches.In 0–20 cm sediment profile,nematode abundance declined abruptly with depth,whereas nematode diversity changed gently with obvious difference in 16–20 cm layer.Sediment granulometry and chlorophyll-a content were the two foremost factors which influenced the vertical distribution pattern of nematode generic diversity.Non-selective deposit feeders constituted the most dominant trophic group,followed by epistratum feeders.Bathylaimus(family:Tripyloididae) dominated at the second and Yangkou beach,while Theristus(family:Xyalidae) prevailed at Shilaoren beach.Omnivores and predators became important at Shilaoren beach because of the high proportion of Enoplolaimus.Even though,nematode community of the studied beaches did not differ significantly from each other.
文摘Response spectra of fixed offshore structures impacted by extreme waves are investigated based on the higher order components of the nonlinear drag force. In this way, steel jacket platforms are simplified as a mass attached to a light cantilever cylinder and their corresponding deformation response spectra are estimated by utilizing a generalized single degree of freedom system. Based on the wave data recorded in the Persian Gulf region, extreme wave loading conditions corresponding to different return periods are exerted on the offshore structures. Accordingly, the effect of the higher order components of the drag force is considered and compared to the linearized state for different sea surface levels. When the fundamental period of the offshore structure is about one third of the main period of wave loading, the results indicate the linearized drag term is not capable of achieving a reliable deformation response spectrum.
基金Supported by the National High Technology Research and Development Program of China (863 Program, No. 2006AA09A309)China Postdoctoral Science Foundation (No. 20070411111)the Fund of Shandong Province for the Excellent Post-Doctors (No. 200603056)
文摘In considering the vertical heat boundary approximation for the free surface applied. However, due to the existence of the transport problems in the upper ocean, the flat upper and the horizontal homogenous hypothesis are usually wave motion, the application of this approximation may result in some errors to the solar irradiation since it decays quickly in respect to the actual thickness of the water layer below the surface; on the other hand, due to the fluctuation of the water layer depth, it is improper to neglect the effects of the horizontal advection and turbulent diffusion since they also contribute to the vertical heat transport. A new model is constructed in this study to reflect these effects. The corresponding numerical simulations show that the wave motion may remarkably accelerate the vertical heat transferring process and the variation of the temperature in the wave affected layer appears in an oscillating manner.
文摘The ‘Freedom of Navigation' issue has been volatile and often influenced by Sino-US relations in recent years. This problem was rooted in different interpretation of the UNCLOS by China and the US. It has also reflected their different national Interests and maritime strategies. This issue has caused frequent frictions between the two sides and may lead to their future contest for sea power. At the same time, it also urges the both sides to set up new mechanism for confidence building that may help them to manage it in a more rational way.
文摘The three water-soluble polysaccharides (PI, PII and Pill), the ethyl acetate extraction (EA) and its five fractions of petroleum ether (PeF), ethyl acetate (EaF), butanol (BuF), methanol (MeF) and water (WtF) from marine agrobacterium 1202 were prepared and then subjected to antioxidant activity evaluation. The antioxidant activity was tested using the 1, 1-Diphenyl-2-picryl-hydrazyl (DPPH) free radical-scavenging assay, the hydrogen peroxide-induced luminot chemiluminescence (CL) assay and hydroxyl free radical-initiated chemiluminescence (CL) assay. All the fractions exerted significant inhibitory effects on hydrogen peroxide and hydroxyl free radical. The extracts of EA, EaF and BuF could also showed inhibition on DPPH. Among of them, the extracts of EaF showed full of antioxidant activity on the three tested system. The result suggested that the marine agrobacterium 1202 is a potential source of natural antioxidantagent.
基金funded by the National Natural Science Foundation of China (No.41576135)the Fundamental Research Funds for Central Universities of the Ministry of Education of China (No.201462008)the National Key Basic Research Program from the Ministry of Science and Technology,People’s Republic of China (No.G1999043709)
文摘Biodiversity pattems of free-living marine nematodes were studied using specific, taxonomic and phylogenetic diversity measures in the southern Yellow Sea, China. The results showed that the average of Shannon-Wiener diversity index (H') in the study area was 3.17. The higher values were distributed in the east part of Shandong coastal waters and north part of Jiangsu coastal waters, while the lower values were distributed in the southern Yellow Sea Cold Water Mass (YSCWM). The average of taxonomic diversity (A) was 62.09 in the study region. The higher values were distributed in the transitional areas between the coastal areas and the southem YSCWM, while the lower values were distributed near the north part of Jiangsu coastal waters and the YSCWM. Results of correlation analysis of species diversity and taxonomic diversity showed that some of the two kinds of diversity index were inde- pendent, which suggested that combining the two kinds of diversity indices can reflect the ecological characteristics better. A test for 95% probability funnels of average taxonomic distinctness and variation in taxonomic distinctness suggested that Station 8794 (in the YSCWM) was outside of the 95% probability funnels, which may be due to the environmental stress. Results of correlation analysis between marine nematodes biodiversity and environmental variables showed that the sediment characteristics (Mdo and Silt-clay fraction) and phaeophorbide a (Pha-a) were the most important factors to determine the biodiversity patterns of marine nematodes.
文摘The ratio between the reactivity of HC and NOx, i.e., φ = ∑kOH+HC, [HCi] / (kOH+No[NO] + kOH+NO2 [NO2]), is used to study the chemistry of HOx radicals (HOE and OH) in the marine boundary layer (MBL). Data analysis shows that HOx production and OH/HO2 ratio strongly depend on φ. The OH radical concentration presents an ascending tendency in low φ region but a de- clining one in high ∞ region, while HO2 radical increases with increasing φ under low φ conditions but appears to be nearly constant with the variation of ∞ under high φ conditions. The observed OH/HO2 ratio shows a continuous decrease with the increase of φ. Model studies are conducted to illuminate the behavior of HOx radicals in different φ regions, and the results represent general agreement with the observed variations of HOx radicals and can well explain the observed behavior of HOx radicals. This study demonstrates that φ could be used as an efficient parameter to ascertain the behavior of HOx radicals in the clean marine boundary layer.