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黄土高原及周边地区间齿螺(Metodontia)种类的数量分布及其温度和降水量最适范围的定量估算 被引量:6
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作者 李丰江 吴乃琴 +6 位作者 董亚杰 吕厚远 陈晓云 张丹 张月婷 黄林培 伍斌 《第四纪研究》 CAS CSCD 北大核心 2016年第3期564-574,共11页
间齿螺(Metodontia)是我国现生陆生蜗牛的常见属,也是黄土地层中常见的蜗牛化石,汉山间齿螺(Metodontiahuaiensis)和烟台间齿螺(Metodontiayantaiensis)是该属的两个常见种。我国现生间齿螺的地理分布调查取得了丰硕的成果,为... 间齿螺(Metodontia)是我国现生陆生蜗牛的常见属,也是黄土地层中常见的蜗牛化石,汉山间齿螺(Metodontiahuaiensis)和烟台间齿螺(Metodontiayantaiensis)是该属的两个常见种。我国现生间齿螺的地理分布调查取得了丰硕的成果,为间齿螺化石作为夏季风气候变化的代用指标提供了依据,但对现生间齿螺的数量分布和生态因子最适区域,还缺少系统的研究,限制了对间齿螺古生态古气候意义的深入理解。通过对黄土高原及周边地区356个表土蜗牛组合的研究,揭示了间齿螺及其优势种的数量分布与气候参数的关系,以及与经纬度和海拔高度的关系,并利用加权平均方法定量估算了汉山间齿螺和烟台间齿螺的温度和降水量最适范围。结果表明,在我们的研究区域内,含量大于20%的间齿螺,主要分布在年均温大于11℃、年降水量550~850mm的地区,36°N以南、110°E以东的地区,海拔在750m以下的地区;含量低于10%的间齿螺,在年均温5~15℃、年降水量380~700mm的地点都有分布,主要分布在33°~40.5°N、103.7°~117.5°E范围内,海拔在2000m以下的地区;年均温低于5℃、年降水量低于380mm的地区,海拔2000m以上的地区,基本上没有间齿螺生长;汉山间齿螺和烟台间齿螺年均温度最适范围分别为10.2~14.1cC左右和8.9~14.O℃左右(实测值与推导值R2=0.70,推导误差RMSEP=1.99),年降水量最适范围分别为530~800mm左右和470~750mm左右(R=0.81,RMSEP=90.87)。上述结果为间齿螺的古生态古气候研究和物种多样性保护提供了基础生态数据。 展开更多
关键词 蜗牛 生态 齿(metodontia) 生态幅定量估算 黄土 黄土高原
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Characteristics of a Drainage Channel with Staggered Indented Sills for Controlling Debris Flows 被引量:4
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作者 CHEN Xiao-qing YOU Yong +2 位作者 CHEN Jian-gang HUANG Kai LI De-ji 《Journal of Mountain Science》 SCIE CSCD 2014年第5期1242-1252,共11页
The characteristics of a new type of drainage channel with staggered indented sills for controlling debris flows were studied. The intermediate fluid in the non-viscous debris flow exhibited a helical movement, wherea... The characteristics of a new type of drainage channel with staggered indented sills for controlling debris flows were studied. The intermediate fluid in the non-viscous debris flow exhibited a helical movement, whereas the fluid near the sidewall had a stop-start movement pattern; the viscous debris flow exhibited a stable structure between the indented sills. The experimental results indicate that the mean velocity of the debris flow increased with increasing channel gradients, and the debris flow velocity was slightly affected by the angle of the sills. The average velocity of the non-viscous debris flow increased in the range of(0.5–1.5) interval between the indented sills, whereas the average velocity of the viscous debris flow increased initially and then decreased in the range of(0.75–1.25) interval between the indented sills. The depth of the non-viscous debris flow tended to gradually increase as the channel gradients increased, whereas the depth of the viscous debris flow gradually decreased as the channel gradients increased. When the discharge of the debris flow was constant, the angle and the interval between the indented sills had a slight effect on the depth of the viscous debris flow, whereas the depth of the non-viscous debris flow exhibited a different trend, as the sill angles and intervals were varied. 展开更多
关键词 Debris flow Drainage channel Staggered indented sill Wenchuan earthquake
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