Taking agricultural development as the starting point,this paper explored the dynamic mechanism and implementation path of agricultural development in Qinba Mountainous Area from the perspective of man-land relationsh...Taking agricultural development as the starting point,this paper explored the dynamic mechanism and implementation path of agricultural development in Qinba Mountainous Area from the perspective of man-land relationship. It found the regular understanding of ecological changes in Qinba Mountains. It is a comprehensive review and exploration on agricultural development and environmental evolution,and aims to provide a historical reference for the development of the contemporary Qinba Mountains.展开更多
Zonation patterns of riparian vegetation have been sampled and described in mountain streams in two catchments in the Hottentots-Holland Mountains, Western Cape, South Africa. Six main vegetation types that differ in ...Zonation patterns of riparian vegetation have been sampled and described in mountain streams in two catchments in the Hottentots-Holland Mountains, Western Cape, South Africa. Six main vegetation types that differ in structure and species composition, are dominant along these river banks: Aquatic vegetation, Wetbanks, Palmiet, Scrub, Forest and Shrubland(Fynbos). The study aims to correlate the vegetation patterns to flooding patterns, in particular the inundation frequency and stream power. A problem arises: because these catchments are ungauged, like most mountain catchments, with the only weirs at the downstream end of the catchment. Discharge data at the weirs are extrapolated to the sites upstream by multiplication with a factor based on the size of the subcatchment that drains through a sample site. In this way, recurrence intervals for floods in mountain streams are derived. Discharges at sites are also calculated using bed roughness(Manning's n) and slope in straight sections with uniform flow conditions. Stream power is derived from the discharges calculated in this manner. The combination of stream power and recurrence intervals explains the occurrence of most vegetation types occurring on the banks, except for one type: Afromontane Forest. This type is probably more dependent on other factors, such as protection from fire and the depth of the groundwater table.展开更多
重点词汇1.weak adj.虚弱的;无力的He was too weak even to lift his hand.他虚弱得连手都抬不起来。短语be weak in不擅长……;在……方面不行He is weak in sight and hearing.他的视力和听力都很差。2.remind v.提醒;使想起(1)remin...重点词汇1.weak adj.虚弱的;无力的He was too weak even to lift his hand.他虚弱得连手都抬不起来。短语be weak in不擅长……;在……方面不行He is weak in sight and hearing.他的视力和听力都很差。2.remind v.提醒;使想起(1)remind sb to do sth提醒某人做某事He reminded me to write the letter.他提醒我写信。(2)remind sb of sth使某人想起某事She reminded him of the last time they had met.她让他想起他们上次的相遇。(3)remind sb+that从句提醒某人……He reminded me that I ought to do it at once.他提醒我应该现在就去做这件事。展开更多
选注者言:天下有此等恶丈夫,竟然将已婚15年的妻子用狗链锁住,原因是妻子要离他而去而已。恶丈夫受到严惩。文章的第一句话非常精彩,颇让人解恨:…a 30-foot dog chain around his wife’s neck and kept her in a cage after shethreat...选注者言:天下有此等恶丈夫,竟然将已婚15年的妻子用狗链锁住,原因是妻子要离他而去而已。恶丈夫受到严惩。文章的第一句话非常精彩,颇让人解恨:…a 30-foot dog chain around his wife’s neck and kept her in a cage after shethreatened to leave him is now in a cage of his own-a prison cell.其中的in展开更多
基金Supported by Major Project Research of Philosophy and Social Science Research of Ministry of Education"General History of Chinese Agricultural Civilization"(13JZD036)
文摘Taking agricultural development as the starting point,this paper explored the dynamic mechanism and implementation path of agricultural development in Qinba Mountainous Area from the perspective of man-land relationship. It found the regular understanding of ecological changes in Qinba Mountains. It is a comprehensive review and exploration on agricultural development and environmental evolution,and aims to provide a historical reference for the development of the contemporary Qinba Mountains.
基金supported by funding from the National Research Foundation to C. Boucher and the VSB Funds (the Netherlands) to E. Siebenadditional funding from the Water Research Commission
文摘Zonation patterns of riparian vegetation have been sampled and described in mountain streams in two catchments in the Hottentots-Holland Mountains, Western Cape, South Africa. Six main vegetation types that differ in structure and species composition, are dominant along these river banks: Aquatic vegetation, Wetbanks, Palmiet, Scrub, Forest and Shrubland(Fynbos). The study aims to correlate the vegetation patterns to flooding patterns, in particular the inundation frequency and stream power. A problem arises: because these catchments are ungauged, like most mountain catchments, with the only weirs at the downstream end of the catchment. Discharge data at the weirs are extrapolated to the sites upstream by multiplication with a factor based on the size of the subcatchment that drains through a sample site. In this way, recurrence intervals for floods in mountain streams are derived. Discharges at sites are also calculated using bed roughness(Manning's n) and slope in straight sections with uniform flow conditions. Stream power is derived from the discharges calculated in this manner. The combination of stream power and recurrence intervals explains the occurrence of most vegetation types occurring on the banks, except for one type: Afromontane Forest. This type is probably more dependent on other factors, such as protection from fire and the depth of the groundwater table.
文摘重点词汇1.weak adj.虚弱的;无力的He was too weak even to lift his hand.他虚弱得连手都抬不起来。短语be weak in不擅长……;在……方面不行He is weak in sight and hearing.他的视力和听力都很差。2.remind v.提醒;使想起(1)remind sb to do sth提醒某人做某事He reminded me to write the letter.他提醒我写信。(2)remind sb of sth使某人想起某事She reminded him of the last time they had met.她让他想起他们上次的相遇。(3)remind sb+that从句提醒某人……He reminded me that I ought to do it at once.他提醒我应该现在就去做这件事。
文摘选注者言:天下有此等恶丈夫,竟然将已婚15年的妻子用狗链锁住,原因是妻子要离他而去而已。恶丈夫受到严惩。文章的第一句话非常精彩,颇让人解恨:…a 30-foot dog chain around his wife’s neck and kept her in a cage after shethreatened to leave him is now in a cage of his own-a prison cell.其中的in
