＂Splitting＂ and ＂lumping＂ are perpetual problems in vertebrate, especially dinosaur, ichnotaxonomy. Chinese dinosaur ichnotaxonomy, which began in 1940, provides a series of interesting case studies, highlighting ...＂Splitting＂ and ＂lumping＂ are perpetual problems in vertebrate, especially dinosaur, ichnotaxonomy. Chinese dinosaur ichnotaxonomy, which began in 1940, provides a series of interesting case studies, highlighting the dual problems of historical and dubious ichnotaxonomy. Chinese Mesozoic tetrapod track types have been placed into 63 ichnospecies （one Triassic, 28 Jurassic, and 34 Cretaceous）, exclusive of other, non-type ichnospecies or ichnotaxa identified from China. Fifty-two （~83%） of these 63 tetrapod ichnospecies were placed in monospecific ichnogenera. At the ichnogenus level, we prune---either by recognizing nomina dubia or by synonymy--17 from the list of 53 dinosaurian ichnogenera （a 32% reduction）, leaving 36 ichnotaxa that we consider valid. Most of the cuts affect Jurassic theropod ichnotaxa, which are reduced from 23 to only nine because most ichnogenera are subjective junior synonyms of Grallator and Eubrontes. Fewer Chinese Cretaceous ichnotaxa （only six of 21 ichnogenera） are obvious nomina dubia or subjective synonyms, suggesting greater east Asian endemism during this time. Because ichnospecies differences are subtle, we provisionally retain ichnospecies as valid pending detailed comparative analyses of congeneric ichnospecies. This synthesis is long overdue and is necessary to address problems of historical and provincial ichnotaxonomy, which severely hamper comparisons of tetrapod ichnofaunas in space and time.展开更多
An incomplete postcranial avian skeleton is described from the Lower Cretaceous Jingchuan Formation of Otog Banner of western Inner Mongolia and referred to a new species of Cathayornis, C. chabuensis sp. nov. This is...An incomplete postcranial avian skeleton is described from the Lower Cretaceous Jingchuan Formation of Otog Banner of western Inner Mongolia and referred to a new species of Cathayornis, C. chabuensis sp. nov. This is the first report of a Cathayornis from outside Liaoning Province. The new discovery indicates that Cathayornis coexisted with Otogornis genghisi, and a more detailed comparison between these two enantiornithine genera shows that Otogornis represents a more primitive genus than Cathayornis. Our analyses further indicate that Cathayornis is an arboreal bird. The discovery of a Cathayornis from this region also confirms that the avian fossil-bearing Jingchuan Formation is comparable to the Jiufotang Formation of the upper Jehol Group in western Liaoning, and should be referred to the middle-late Early Cretaceous.展开更多
Considering the danger of water inrush in mining very thick coal seam under water-rich roof in Majialiang Coal Mine,the universal discrete element(UDEC)software was used to simulate the overburden fracture evolution l...Considering the danger of water inrush in mining very thick coal seam under water-rich roof in Majialiang Coal Mine,the universal discrete element(UDEC)software was used to simulate the overburden fracture evolution laws when mining 4#coal seam.Besides,this study researched on the influence of face advancing length,speed and mining height on the height of the water flowing fractured zones(HWFFZ),and analyzed the correlation of face advancing length and change rules of aquifer water levels and goaf water inflow.Based on those mentioned above,this research proposed the following water-controlling technologies:draining the roof water before mining,draining goaf water,reasonable advancing speed and mining thickness.These water-controlling technologies were successfully used in the feld,thus ensured safely mining the very thick coal seam under water-rich roof.展开更多
Reagents:PMS(KHSO_(5)·0.5KHSO_(4)·0.5K_(2)SO_(4),KHSO_(5)),MO,cobalt chloride(CoCl_(2)·6H_(2)O),ferric chloride(FeCl3·6H_(2)O),sodium metasilicate nonahydrate(Na_(2)SiO_(3)·9H_(2)O),methanol(M...Reagents:PMS(KHSO_(5)·0.5KHSO_(4)·0.5K_(2)SO_(4),KHSO_(5)),MO,cobalt chloride(CoCl_(2)·6H_(2)O),ferric chloride(FeCl3·6H_(2)O),sodium metasilicate nonahydrate(Na_(2)SiO_(3)·9H_(2)O),methanol(MeOH),tert-butyl alcohol(TBA),p-Benzoquinone(p-BQ),furfuryl alcohol(FFA),sodium carbonate(Na_(2)CO_(3)),sodium sulfate(Na_(2)SO_(4)),sodium chloride(NaCl)and potassium phosphate monobasic(KH_(2)PO_(4))were purchased from Aladdin Reagent Co.,Ltd(Shanghai,China).Coal gangue were collected from Huainan,China.All chemicals above are analytical grade,and deionized water was used throughout all experiments.展开更多
基金Natural Science Foundation of Anhui Province(1908085ME127)Research Foundation of the Institute of Environmentfriendly Materials and Occupational Health(Wuhu),Anhui University of Science and Technology(ALW2021YF11)。
基金supported by the Grant-in-Aid for Scientific Research of the Japan Society for the Promotion of Science(to Masaki Matsukawa,no.1183303,1999-2000)the Grant-in Aid for University and Society Collaboration of the Japanese Ministry of Education, Science,Sports and Culture(to Masaki Matsukawa,no. 11791012,1999-2001)+2 种基金The Shandong portion of this study was supported financially,in part,by the National Natural Science Foundation of China grant no.40972005 to Rihui LiThe Nei Mongol portion of this study was supported by a grant from the National Natural Science Foundation of China(40872005) to Jianjun Lithe Beijing Museum of Natural History,with supplemental support from the Dinosaur Tracks Museum,University of Colorado Denver
文摘＂Splitting＂ and ＂lumping＂ are perpetual problems in vertebrate, especially dinosaur, ichnotaxonomy. Chinese dinosaur ichnotaxonomy, which began in 1940, provides a series of interesting case studies, highlighting the dual problems of historical and dubious ichnotaxonomy. Chinese Mesozoic tetrapod track types have been placed into 63 ichnospecies （one Triassic, 28 Jurassic, and 34 Cretaceous）, exclusive of other, non-type ichnospecies or ichnotaxa identified from China. Fifty-two （~83%） of these 63 tetrapod ichnospecies were placed in monospecific ichnogenera. At the ichnogenus level, we prune---either by recognizing nomina dubia or by synonymy--17 from the list of 53 dinosaurian ichnogenera （a 32% reduction）, leaving 36 ichnotaxa that we consider valid. Most of the cuts affect Jurassic theropod ichnotaxa, which are reduced from 23 to only nine because most ichnogenera are subjective junior synonyms of Grallator and Eubrontes. Fewer Chinese Cretaceous ichnotaxa （only six of 21 ichnogenera） are obvious nomina dubia or subjective synonyms, suggesting greater east Asian endemism during this time. Because ichnospecies differences are subtle, we provisionally retain ichnospecies as valid pending detailed comparative analyses of congeneric ichnospecies. This synthesis is long overdue and is necessary to address problems of historical and provincial ichnotaxonomy, which severely hamper comparisons of tetrapod ichnofaunas in space and time.
基金Supported by the Major Basic Research Projects(2006CB806400)of MST of China,the Chinese Academy of Sciences(kzcx3-sw-142)the National Natural Science Foundation of China(40121202)
文摘An incomplete postcranial avian skeleton is described from the Lower Cretaceous Jingchuan Formation of Otog Banner of western Inner Mongolia and referred to a new species of Cathayornis, C. chabuensis sp. nov. This is the first report of a Cathayornis from outside Liaoning Province. The new discovery indicates that Cathayornis coexisted with Otogornis genghisi, and a more detailed comparison between these two enantiornithine genera shows that Otogornis represents a more primitive genus than Cathayornis. Our analyses further indicate that Cathayornis is an arboreal bird. The discovery of a Cathayornis from this region also confirms that the avian fossil-bearing Jingchuan Formation is comparable to the Jiufotang Formation of the upper Jehol Group in western Liaoning, and should be referred to the middle-late Early Cretaceous.
基金provided by the Priority Academic Program Development of Jiangsu Higher Education Institutions of China(No.SZBF2011-6-B35)the Fundamental Research Funds for the Central Universities of China(No.2012LWB42)
文摘Considering the danger of water inrush in mining very thick coal seam under water-rich roof in Majialiang Coal Mine,the universal discrete element(UDEC)software was used to simulate the overburden fracture evolution laws when mining 4#coal seam.Besides,this study researched on the influence of face advancing length,speed and mining height on the height of the water flowing fractured zones(HWFFZ),and analyzed the correlation of face advancing length and change rules of aquifer water levels and goaf water inflow.Based on those mentioned above,this research proposed the following water-controlling technologies:draining the roof water before mining,draining goaf water,reasonable advancing speed and mining thickness.These water-controlling technologies were successfully used in the feld,thus ensured safely mining the very thick coal seam under water-rich roof.
文摘Reagents:PMS(KHSO_(5)·0.5KHSO_(4)·0.5K_(2)SO_(4),KHSO_(5)),MO,cobalt chloride(CoCl_(2)·6H_(2)O),ferric chloride(FeCl3·6H_(2)O),sodium metasilicate nonahydrate(Na_(2)SiO_(3)·9H_(2)O),methanol(MeOH),tert-butyl alcohol(TBA),p-Benzoquinone(p-BQ),furfuryl alcohol(FFA),sodium carbonate(Na_(2)CO_(3)),sodium sulfate(Na_(2)SO_(4)),sodium chloride(NaCl)and potassium phosphate monobasic(KH_(2)PO_(4))were purchased from Aladdin Reagent Co.,Ltd(Shanghai,China).Coal gangue were collected from Huainan,China.All chemicals above are analytical grade,and deionized water was used throughout all experiments.
