A consecutive sediment core (CC2) was drilledin Chen Co (lake) of southern Tibet using a PISTON samplerin 1998 AD. Cladoceran remains including their species,amount richness and ecological features are analyzed for th...A consecutive sediment core (CC2) was drilledin Chen Co (lake) of southern Tibet using a PISTON samplerin 1998 AD. Cladoceran remains including their species,amount richness and ecological features are analyzed for thetop 117 cm sections of the core, upon which 5 cladoceranassemblages are distinguished. CL0 is an assemblage withoutany cladocera in the depth between 117-105 cm. CL1 as-semblage (depths between 101-77 cm, ca. 1407-1533 AD)possesses total 9 cladoceran species that appear in the core,and performs the greatest richness in the whole sequence.This assemblage reflected that there was plenty of exotic coldwater and organic debrises inputing to the sedimentary siteunder the warmer conditions. The lake was wide and shallowthat satisfied the big hydrophyte living. Cladoceran speciesand richnesses of CL2 assemblage (depths between 77-29cm, ca. 1533-1831 AD) perform much more decreasing thanthose of CL1. There was only less Chydorus sphaericus whichwas acclimatized to wide environmental ranges. This impliedthat the sedimentary environment is so execrable that mostof cladoceran lost their living abilities. Compared with CL1assemblage, CL3 assemblage (depths between 29-10 cm, ca.1831-1941 AD) possesses nearly the same dominant speciesbut lower richnesses. Especially, the cladoceran preferringorganic debris also decrease in their amounts. This meantthat the surface vegetation in the drainage basin was stillpoor though the environment turned to be better. Except the2 zooplankton species, the other 7 species of cladoceran inthis core are found in CL4 assemblage (depths between 10-0 cm, ca. 1941-1998 AD), in which the eurythermal specieshad not performed their competition ability comparing withnarrow-temperatures adapted species. It implied that watertemperatures were stable and much more influenced by airtemperatures under the shallow-water conditions. The envi-ronmental features reflected by cladocera assemblages ofCC2 core are fully supported by the evidences from ostra-coda assemblages, diatom-salinity transfunct展开更多
火灾概率预测是减少和控制高层建筑火灾的基本手段，计算非确定性需求的关键是确定火灾发生的概率。本文基于封高层建筑火灾风险因素的综合分析，确定了高层建筑火灾风险源因素FTA（Fault Tree Analysis）分析方法，目的在于为FTA方法...火灾概率预测是减少和控制高层建筑火灾的基本手段，计算非确定性需求的关键是确定火灾发生的概率。本文基于封高层建筑火灾风险因素的综合分析，确定了高层建筑火灾风险源因素FTA（Fault Tree Analysis）分析方法，目的在于为FTA方法在火灾概率预测方法上的应用提供一种新的尝试，为采取合理的高层建筑火灾防治技术措施在理论上、方法上提供有益的指导。展开更多
基金jointly funded by Knowledge Innovalion Project of Chinese Academy of Sciences(Grant Nos.KZCX3-SW-321 and KZCX3-SW-339)Innovation Project of Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences(Grant No.CXIOG-E01-05-02)Sino-Slovenia Bilateral Technological Cooperation Project of Ministry of Science and Technology China
文摘A consecutive sediment core (CC2) was drilledin Chen Co (lake) of southern Tibet using a PISTON samplerin 1998 AD. Cladoceran remains including their species,amount richness and ecological features are analyzed for thetop 117 cm sections of the core, upon which 5 cladoceranassemblages are distinguished. CL0 is an assemblage withoutany cladocera in the depth between 117-105 cm. CL1 as-semblage (depths between 101-77 cm, ca. 1407-1533 AD)possesses total 9 cladoceran species that appear in the core,and performs the greatest richness in the whole sequence.This assemblage reflected that there was plenty of exotic coldwater and organic debrises inputing to the sedimentary siteunder the warmer conditions. The lake was wide and shallowthat satisfied the big hydrophyte living. Cladoceran speciesand richnesses of CL2 assemblage (depths between 77-29cm, ca. 1533-1831 AD) perform much more decreasing thanthose of CL1. There was only less Chydorus sphaericus whichwas acclimatized to wide environmental ranges. This impliedthat the sedimentary environment is so execrable that mostof cladoceran lost their living abilities. Compared with CL1assemblage, CL3 assemblage (depths between 29-10 cm, ca.1831-1941 AD) possesses nearly the same dominant speciesbut lower richnesses. Especially, the cladoceran preferringorganic debris also decrease in their amounts. This meantthat the surface vegetation in the drainage basin was stillpoor though the environment turned to be better. Except the2 zooplankton species, the other 7 species of cladoceran inthis core are found in CL4 assemblage (depths between 10-0 cm, ca. 1941-1998 AD), in which the eurythermal specieshad not performed their competition ability comparing withnarrow-temperatures adapted species. It implied that watertemperatures were stable and much more influenced by airtemperatures under the shallow-water conditions. The envi-ronmental features reflected by cladocera assemblages ofCC2 core are fully supported by the evidences from ostra-coda assemblages, diatom-salinity transfunct
文摘火灾概率预测是减少和控制高层建筑火灾的基本手段，计算非确定性需求的关键是确定火灾发生的概率。本文基于封高层建筑火灾风险因素的综合分析，确定了高层建筑火灾风险源因素FTA（Fault Tree Analysis）分析方法，目的在于为FTA方法在火灾概率预测方法上的应用提供一种新的尝试，为采取合理的高层建筑火灾防治技术措施在理论上、方法上提供有益的指导。
