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1.
This review article commences with a comprehensive historical review of the evolution and application of various density surfaces in atmospheric and oceanic studies. The background provides a basis for the birth of the neutral density idea. Attention is paid to the development of the neutral density surface concept from the nonlinearity of the equation of state of seawater. The definition and properties of neutral density surface are described in detail as developed from the equations of state of seawater and the buoyancy frequency when the squared buoyancy frequency N2 is zero, a neutral state of stability. In order to apply the neutral density surface to intermediate water-mass analysis, this review also describes in detail its practical oceanographic application. The mapping technique is focused for the first time on applying regularly gridded data in this review. It is reviewed how a backbone and ribs framework was designed to flesh out from a reference cast and first mapped the global neutral surfaces in the world's oceans. Several mapped neutral density surfaces are presented as examples for each world ocean. The water-mass property is analyzed in each ocean at mid-depth. The characteristics of neutral density surfaces are compared with those of potential density surfaces.  相似文献   

2.
1INTRODUCTIONThegenusTinocladiaKylinderivedfromthege nusEudesmeJ.Ag.,wasestablishedbyKylinin1 940 .Untilnow ,fivespecieshavebeenreported .Threespecies,T .crassa (Sur.)Kylin(byC .K .Tseng,1 983 ) ,T .gracilisDingetLuandT .mi crosporangiiDingetLu (byDingetal.,2 0 0 4)inthegenusTinocladiahadbeenreportedtodate.Inthecourseofourinvestigationonthespecimensofthege nusTinocladiacollectedfromtheYellowSeacoastsandkeptintheHerbariumoftheInstituteofOceanolo gy,ChineseAcademyofSciences,twomo…  相似文献   

3.
A total of 69 strains of thermophilic bacteria were isolated from water, soil and sediment samples from three Indonesia’s hot spring areas (Pantai cermin, Kalianda and Banyu wedang) by using Minimal Synthetic Medium (MSM). The extreme thermophile Brevibacillus sp. PLI-1 was found to produce extracellular thermophilic alkaline protease with optimal activity at 70℃ and pH 8.0-9.0. The molecular weight of the protease was estimated to be around 56 kD by SDS-PAGE. The maximum activity of the protease was 26.54 U mL-1. The protease activity did not decrease after 30 min and still retained more than 70% of relative activity after 60 min at 70℃ and pH 8.0. The ion Mg2+ was found to promote protease activity at both low and high concentrations, whereas Cu2+ and Zn2+ could almost completely inhibit the activity. Divalent cation chelator EDTA inhibited the enzyme activity by 55.06% ± 0.27%, while the inhibition caused by PMSF, Leupeptin, Pepstain A and Benzamidine were 66.78% ± 3.25%, 52.37% ± 0.25%, 62.47% ± 2.96% and 50.99% ± 0.24%, respectively. Based on these observations, the enzyme activity was conspicuously sensitive to the serine and cysteine protease inhibitors. All these results indicated that the protease isolated from the strain PLI-1 was a thermophilic protease and had a high-temperature stability and a pH stability.  相似文献   

4.
①TheprojectsupportedbytheNationalNaturalScienceFoundationofChina.Mountainglacierisaproductofmutuallyjointactionofclimateandtopography.AtthisPOint,climaticchangemakeglacieradapttoitschangethroughadjustingglacierareaandlengthfollowingtheglacierinnermovementlaw.Intheory,glacieralwayscorreSpondstoastablestateunderacertainclimaticcondition.Becauseoflimitationoftheglaciermovementlaw,theglacierhastograduallyadapttOclimaticchange.Also,climateisalwaysinchange.So,itisalmostimPOSSibleforglaciertor…  相似文献   

5.
A new genus of the deep-sea pontoniine shrimps, Bathymenes gen. nov., is established for the ‘Periclimenes alcocki species group’ of the genus Periclimenes Costa, 1844. The new genus is distinguished from other genera of the Pontoniinae by a combination of characters: the posteriormost dorsal rostral tooth remote from other teeth, situated in the epigastric position, cornea usually reduced, the propodus of second pereiopods covered with fine granules, the dactylus of the major second chela being generally flanged, the ambulatory pereiopods with the dactyli being biunguiculate and telson with more than two pairs of dorsolateral spines. The genus is mainly distributed in the tropical to warm-temperate Indo-West Pacific waters at depths greater than 200 m. Fifteen species previously recognized as belonging to the ‘P. a lcocki species group’ are now placed in Bathymenes gen. nov. A key for their identification and a checklist of congeneric species are provided.  相似文献   

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