The mitochondrial genome(mitogenome)analysis is a significant tool for investigating the evolutionary history of metazoan animals.The family Pandalidae is a diverse caridean group containing mainly deep-sea species.Un...The mitochondrial genome(mitogenome)analysis is a significant tool for investigating the evolutionary history of metazoan animals.The family Pandalidae is a diverse caridean group containing mainly deep-sea species.Until May 302019,only two complete mitogenomes are available in GenBank.Here we present the complete mitogenome sequences of two deep-sea pandalid shrimps,Heterocarpus ensifer and Bitias brevis through Illumina sequencing.The mitochondrial genomes were determined to be 15939 bp and 15891 bp long,and both consist of 13 protein-coding genes(PCGs),23 transfer-RNA genes(tRNAs),two ribosomal-RNA genes(rRNAs),and one control region.The nucleotide composition is biased toward adenine and thymine.Overall,the gene contents and arrangements are consistent with the pancrustacean ground pattern.The alignment of the control regions of four pandalids reveals a conserved sequence block(CSB)(104 bp in length,average GC%=29.47%and 69.23%similarity).A phylogenetic analysis based on 51 Caridea complete mitogenomes revealed that the deep-sea pandalid shrimps are situated an intermediate lineage,with a tendency to originated from those living in shallow sea area.展开更多
The deep-sea is considered as the most extensive ecosystem on the Earth.It is meaningful for elucidating the life origins by exploring the origin and adaptive genetic mechanisms of the large deepsea organisms.Caridean...The deep-sea is considered as the most extensive ecosystem on the Earth.It is meaningful for elucidating the life origins by exploring the origin and adaptive genetic mechanisms of the large deepsea organisms.Caridean shrimps have colonized and successfully adapted to deep-sea environments.They provide an ideal model to analyze the origin and adaptive evolution of modern deep-sea fauna.Here,we conducted the phylogenetic analyses of mitocho ndrial genomes(mitogenomes)from carideans,including 11 newly sequences reported in this investigation to explore the habitat origins,divergence times,and adaptive evolution of deep-sea(seamounts and hydrothermal vents)caridean shrimps.The results showed that the species of deep-sea Caridea formed a monophyletic group.Phylogenetic analysis supported that the deepsea caridean shrimps may originated from shallow sea.The hydrothermal vents alvinocaridid shrimps and Lebbeus shinkaiae from Thoridae underwent a second range expansion from seamounts to vent ecosystems.Estimates of divergence time showed that the caridean shrimps invaded into deep-sea at 147.75 Ma.The divergence of most of the modern seamount and hydrothermal vent species are in the late Cretaceous/early Tertiary.This may associate with the geological events of the Western Pacific,the climate change,and the global deep-water anoxic/dysoxic events during this period.Twenty-two potentially important adaptive residues were detected in the deep-sea shrimp lineage,which were located in atp6,atp8,cox1,cox3,cytb,nad2,nad4 l,and nad5.This investigation adds our understanding of the evolutionary history of deep-sea caridean shrimps,and provides insights into the mitochondrial genetic basis of deep-sea adaptation in this group.展开更多
This paper presents a comprehensive review and analysis of ship hull cleaning technologies.Various cleaning methods and devices applied to dry-dock cleaning and underwater cleaning are introduced in detail,including r...This paper presents a comprehensive review and analysis of ship hull cleaning technologies.Various cleaning methods and devices applied to dry-dock cleaning and underwater cleaning are introduced in detail,including rotary brushes,high-pressure and cavitation water jet technology,ultrasonic technology,and laser cleaning technology.The application of underwater robot technology in ship cleaning not only frees divers from engaging in heavy work but also creates safe and efficient industrial products.Damage to the underlying coating of the ship caused by the underwater cleaning operation can be minimized by optimizing the working process of the underwater cleaning robot.With regard to the adhesion technology mainly used in underwater robots,an overview of recent developments in permanent magnet and electromagnetic adhesion,negative pressure force adhesion,thrust force adhesion,and biologically inspired adhesion is provided.Through the analysis and comparison of current underwater robot products,this paper predicts that major changes in the application of artificial intelligence and multirobot cooperation,as well as optimization and combination of various technologies in underwater cleaning robots,could be expected to further lead to breakthroughs in developing next-generation robots for underwater cleaning.展开更多
The circum-Pacific convergent margin is known as"the Ring of Fire",with abundant volcano eruptions.Large eruptions are rare but very disastrous.It remains obscure how are large explosive volcanos formed and ...The circum-Pacific convergent margin is known as"the Ring of Fire",with abundant volcano eruptions.Large eruptions are rare but very disastrous.It remains obscure how are large explosive volcanos formed and where are the danger zones.Three largest eruptions since 1900,the Hunga Tonga-Hunga Ha’apai,the Mt.Pinatubo,and the Novarupta were found to be associated with subductions of volatile-rich sediments and located close to slab windows.Among them,the Hunga Tonga-Hunga Ha’apai is close to subducting seamount chains;the Mt.Pinatubo is right next to subducting fossil ridges.Both seamount chains and fossil ridges have water depths much shallower than the carbonate compensation depths(CCD)in the Pacific Ocean.Seismic image shows that a seamount is subducting towards the Novarupta volcano.Subduction of volatile-rich sediments and a slab window nearby are the two most important favorable conditions for catastrophic eruptions.Slab windows expose the mantle wedge to the hot asthenosphere,which increases the temperature and dramatically promotes the partial melting of the carbonate-fluxed domains,forming volatile-rich magmas that powered explosive eruptions.展开更多
The polychaete species of Capitella are widely distributed in the China seas,however little is known about Capitella taxonomy,and specimens collected from China have been identifi ed as Capitella capitata(Fabricius,17...The polychaete species of Capitella are widely distributed in the China seas,however little is known about Capitella taxonomy,and specimens collected from China have been identifi ed as Capitella capitata(Fabricius,1780)for more than 50 years.C.capitata was considered to be Arctic and subarctic in distribution,therefore the records of C.capitata in the China seas probably represent other species.A taxonomic study based on the samples collected from the northeast coastal water of Shandong Province reveals a diff erent species,Capitella teleta Blake et al.,2009,which is recorded in the China seas for the fi rst time.Morphologically,C.teleta can be easily distinguished from C.capitata by the absence of neuropodial capillaries on chaetigers 8 and 9.The identity of C.teleta is further supported by genetic distance and phylogenetic analyses assessed from mitochondrial cytochrome c oxidase subunit I(COI)gene.In addition,the regeneration feature of C.teleta was studied through whole mount immunohistochemistry and chemical staining.After amputation,the wound of C.teleta was healed within 24 h,forming a signifi cant regeneration blastema by 3 days post amputation(dpa).By 5 dpa,muscle tissues regenerated,nerve fi bers also extended.By 7 dpa,neurites and muscle tissues are both signifi cantly regenerated.Notably,there are more than ten segments regenerated until 16 dpa.As a highly opportunistic species,Capitella teleta is distributed in China,Japan,Korea,North America,and the Mediterranean.It is expected to be an excellent model for studying developmental genetics and evolution of regeneration.展开更多
Numerical wave tanks are widely-acknowledged tools in studying waves and wave-structure interactions. They can generate waves under realistic scales and offers more information on the fluid field. However, most numeri...Numerical wave tanks are widely-acknowledged tools in studying waves and wave-structure interactions. They can generate waves under realistic scales and offers more information on the fluid field. However, most numerical wave tanks suffer from issues known as the numerical dissipation and numerical dispersion. The former causes wave energy to be slowly dissipated and the latter shifts wave frequencies during wave propagation. This paper proposes a simple method of depressing numerical dissipation effects on the basis of solving Euler equations using the finite difference method(FDM). The wave propagation solutions are solved analytically taking into account the influence of the damping terms. The main idea of the method is to append a source term to the momentum equation, whose strength is determined by how strong the numerical damping effect is. The method is verified by successfully depressing numerical effects during the simulation of regular linear waves, Stokes waves and irregular waves. By applying the method, wave energy is able to be close to its initial value after long distance of travel.展开更多
基金Supported by the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(CAS)(No.QYZDB-SSW-DQC036)the Strategic Priority Research Program of CAS(No.XDA22050302)+1 种基金the Senior User Project of R/V Kexue(No.KEXUE2019GZ02)the National Natural Science Foundation of China(No.31872215)。
文摘The mitochondrial genome(mitogenome)analysis is a significant tool for investigating the evolutionary history of metazoan animals.The family Pandalidae is a diverse caridean group containing mainly deep-sea species.Until May 302019,only two complete mitogenomes are available in GenBank.Here we present the complete mitogenome sequences of two deep-sea pandalid shrimps,Heterocarpus ensifer and Bitias brevis through Illumina sequencing.The mitochondrial genomes were determined to be 15939 bp and 15891 bp long,and both consist of 13 protein-coding genes(PCGs),23 transfer-RNA genes(tRNAs),two ribosomal-RNA genes(rRNAs),and one control region.The nucleotide composition is biased toward adenine and thymine.Overall,the gene contents and arrangements are consistent with the pancrustacean ground pattern.The alignment of the control regions of four pandalids reveals a conserved sequence block(CSB)(104 bp in length,average GC%=29.47%and 69.23%similarity).A phylogenetic analysis based on 51 Caridea complete mitogenomes revealed that the deep-sea pandalid shrimps are situated an intermediate lineage,with a tendency to originated from those living in shallow sea area.
基金the National Science Fund for Distinguished Young Scholars(No.42025603)the"Research Program of Frontier Sciences"of the Chinese Academy of Sciences(No.QYZDB-SSWDQC036)+1 种基金the National Natural Science Foundation of China(No.31801961)the Strategic Priority Research Program of the Chinese Academy of Science(No.XDB42030301)。
文摘The deep-sea is considered as the most extensive ecosystem on the Earth.It is meaningful for elucidating the life origins by exploring the origin and adaptive genetic mechanisms of the large deepsea organisms.Caridean shrimps have colonized and successfully adapted to deep-sea environments.They provide an ideal model to analyze the origin and adaptive evolution of modern deep-sea fauna.Here,we conducted the phylogenetic analyses of mitocho ndrial genomes(mitogenomes)from carideans,including 11 newly sequences reported in this investigation to explore the habitat origins,divergence times,and adaptive evolution of deep-sea(seamounts and hydrothermal vents)caridean shrimps.The results showed that the species of deep-sea Caridea formed a monophyletic group.Phylogenetic analysis supported that the deepsea caridean shrimps may originated from shallow sea.The hydrothermal vents alvinocaridid shrimps and Lebbeus shinkaiae from Thoridae underwent a second range expansion from seamounts to vent ecosystems.Estimates of divergence time showed that the caridean shrimps invaded into deep-sea at 147.75 Ma.The divergence of most of the modern seamount and hydrothermal vent species are in the late Cretaceous/early Tertiary.This may associate with the geological events of the Western Pacific,the climate change,and the global deep-water anoxic/dysoxic events during this period.Twenty-two potentially important adaptive residues were detected in the deep-sea shrimp lineage,which were located in atp6,atp8,cox1,cox3,cytb,nad2,nad4 l,and nad5.This investigation adds our understanding of the evolutionary history of deep-sea caridean shrimps,and provides insights into the mitochondrial genetic basis of deep-sea adaptation in this group.
基金Supported by the General Program of the National Natural Science Foundation of China under Grant No.51879157the“Construction of a Leading Innovation Team”project by the Hangzhou Municipal Governmentthe Startup Funding of Newjoined PI of Westlake University under Grant No.041030150118。
文摘This paper presents a comprehensive review and analysis of ship hull cleaning technologies.Various cleaning methods and devices applied to dry-dock cleaning and underwater cleaning are introduced in detail,including rotary brushes,high-pressure and cavitation water jet technology,ultrasonic technology,and laser cleaning technology.The application of underwater robot technology in ship cleaning not only frees divers from engaging in heavy work but also creates safe and efficient industrial products.Damage to the underlying coating of the ship caused by the underwater cleaning operation can be minimized by optimizing the working process of the underwater cleaning robot.With regard to the adhesion technology mainly used in underwater robots,an overview of recent developments in permanent magnet and electromagnetic adhesion,negative pressure force adhesion,thrust force adhesion,and biologically inspired adhesion is provided.Through the analysis and comparison of current underwater robot products,this paper predicts that major changes in the application of artificial intelligence and multirobot cooperation,as well as optimization and combination of various technologies in underwater cleaning robots,could be expected to further lead to breakthroughs in developing next-generation robots for underwater cleaning.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA22050103)the Taishan Scholar Program of Shandong(No.ts201712075)。
文摘The circum-Pacific convergent margin is known as"the Ring of Fire",with abundant volcano eruptions.Large eruptions are rare but very disastrous.It remains obscure how are large explosive volcanos formed and where are the danger zones.Three largest eruptions since 1900,the Hunga Tonga-Hunga Ha’apai,the Mt.Pinatubo,and the Novarupta were found to be associated with subductions of volatile-rich sediments and located close to slab windows.Among them,the Hunga Tonga-Hunga Ha’apai is close to subducting seamount chains;the Mt.Pinatubo is right next to subducting fossil ridges.Both seamount chains and fossil ridges have water depths much shallower than the carbonate compensation depths(CCD)in the Pacific Ocean.Seismic image shows that a seamount is subducting towards the Novarupta volcano.Subduction of volatile-rich sediments and a slab window nearby are the two most important favorable conditions for catastrophic eruptions.Slab windows expose the mantle wedge to the hot asthenosphere,which increases the temperature and dramatically promotes the partial melting of the carbonate-fluxed domains,forming volatile-rich magmas that powered explosive eruptions.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB42000000)to L Zthe National Natural Science Foundation of China(No.41976088)to L Z+1 种基金the Key Development Project of Centre for Ocean Mega-Research of Science,Chinese academy of science(No.COMS2019R01)to L Zthe Pilot National Laboratory for Marine Science and Technology(No.YJ2019NO01)to L Z。
文摘The polychaete species of Capitella are widely distributed in the China seas,however little is known about Capitella taxonomy,and specimens collected from China have been identifi ed as Capitella capitata(Fabricius,1780)for more than 50 years.C.capitata was considered to be Arctic and subarctic in distribution,therefore the records of C.capitata in the China seas probably represent other species.A taxonomic study based on the samples collected from the northeast coastal water of Shandong Province reveals a diff erent species,Capitella teleta Blake et al.,2009,which is recorded in the China seas for the fi rst time.Morphologically,C.teleta can be easily distinguished from C.capitata by the absence of neuropodial capillaries on chaetigers 8 and 9.The identity of C.teleta is further supported by genetic distance and phylogenetic analyses assessed from mitochondrial cytochrome c oxidase subunit I(COI)gene.In addition,the regeneration feature of C.teleta was studied through whole mount immunohistochemistry and chemical staining.After amputation,the wound of C.teleta was healed within 24 h,forming a signifi cant regeneration blastema by 3 days post amputation(dpa).By 5 dpa,muscle tissues regenerated,nerve fi bers also extended.By 7 dpa,neurites and muscle tissues are both signifi cantly regenerated.Notably,there are more than ten segments regenerated until 16 dpa.As a highly opportunistic species,Capitella teleta is distributed in China,Japan,Korea,North America,and the Mediterranean.It is expected to be an excellent model for studying developmental genetics and evolution of regeneration.
基金The National Natural Science Foundation of China under contract No.51609101 and 51909103the Natural Science Foundation of Fujian Province of China under contract Nos 2017J01701,2017J05085 and 2018J05090the Outstanding Young University Scientific Research Talents Cultivation Plan of Fujian Province of China
文摘Numerical wave tanks are widely-acknowledged tools in studying waves and wave-structure interactions. They can generate waves under realistic scales and offers more information on the fluid field. However, most numerical wave tanks suffer from issues known as the numerical dissipation and numerical dispersion. The former causes wave energy to be slowly dissipated and the latter shifts wave frequencies during wave propagation. This paper proposes a simple method of depressing numerical dissipation effects on the basis of solving Euler equations using the finite difference method(FDM). The wave propagation solutions are solved analytically taking into account the influence of the damping terms. The main idea of the method is to append a source term to the momentum equation, whose strength is determined by how strong the numerical damping effect is. The method is verified by successfully depressing numerical effects during the simulation of regular linear waves, Stokes waves and irregular waves. By applying the method, wave energy is able to be close to its initial value after long distance of travel.
