S:Adult dragonfly communities were dominated by Libellulidae as 29 species were successfully collected from this family in marginal areas of Saleh, Setul and Serdang rivers. Zygopterans Coenagrionidae, Platycnemididae...S:Adult dragonfly communities were dominated by Libellulidae as 29 species were successfully collected from this family in marginal areas of Saleh, Setul and Serdang rivers. Zygopterans Coenagrionidae, Platycnemididae, Calopterygidae were common while Gomphidae and Chlorocyphidae were rather rare. Libellulids Neurothemis fluctuans, Trithemis aurora, Crocothemis servilia, T. festiva and Orthetrum chrysis were widely distributed in shaded, muddy areas. Among the zygopterans, Pseudagrion pruinosumwas the most dominant species. Agriocnemis femina, Ictinogomphus rapax, Cratilla lineata, Lathrecista asiatica, Neurothemis tullia, Tholymis tillarga and Copera ciliata were strictly found at Saleh River implicating their preference for smaller, slow moving and polluted river with floating microphytes and few other surrounding plant species. Neurobasis chinensis and Vestalis gracilis were only found in open, undisturbed, fast flowing waters of Setul and Serdang rivers. Generally the adults perched on marginal vegetation as well as those on the river bank areas.展开更多
Focusing on the 18 counties along “One River and Two Tributaries” region, and based on the data from China 3nl, 4th and 5th population censuses, this article has analyzed the time and spatial changing patterns of th...Focusing on the 18 counties along “One River and Two Tributaries” region, and based on the data from China 3nl, 4th and 5th population censuses, this article has analyzed the time and spatial changing patterns of the population in this region. The analyses show that since the 3nl population census, total population, average age and total birth rate have all changed considerably: ① Total population has grown, fast, with most counties' annual average growth rate of more than 10. ② In terms of the region's average age, in 2000 the age in the 18 counties is younger than 30 years old. ③ Compared with the 3nl population census, labor force by the 5th census is much younger. ④ Countermeasures are proposed to control population by controlling birth rate as the result of the local resident's quality improvement by education.展开更多
Focusing on the region of Yarlung Zangbo River and the middle reaches of itstwo tributaries of Nianchu River and Lhasa River in Tibet (Hereafter referred to as the 'One Riverand Two Tributaries' region), and b...Focusing on the region of Yarlung Zangbo River and the middle reaches of itstwo tributaries of Nianchu River and Lhasa River in Tibet (Hereafter referred to as the 'One Riverand Two Tributaries' region), and based on the data from China 3rd, 4th and5th population censuses,the article has analyzed change patterns of this region' s labor force. Major findings from thestudy are summarized as follows; (1) Compared with the data from the 3rd census, labor forcepopulation in 2000 has increased significantly. (2) Children dependency coefficient has dropped,while old people dependency coefficient has changed very slightly with an increase of 0. 047% only.(3) Compared 2000 with 1982, illiteracy and semi-illiteracy rate of the population above 15 yearsold have decreased significantly by 30. 69 percentage points, but still higher than the nationalaverage. (4) Women' s illiteracy rate has dropped faster than men's, but up to 2000 it was generallyquite high. The upgrading of the entire population's overall quality has a long way to go.展开更多
文摘S:Adult dragonfly communities were dominated by Libellulidae as 29 species were successfully collected from this family in marginal areas of Saleh, Setul and Serdang rivers. Zygopterans Coenagrionidae, Platycnemididae, Calopterygidae were common while Gomphidae and Chlorocyphidae were rather rare. Libellulids Neurothemis fluctuans, Trithemis aurora, Crocothemis servilia, T. festiva and Orthetrum chrysis were widely distributed in shaded, muddy areas. Among the zygopterans, Pseudagrion pruinosumwas the most dominant species. Agriocnemis femina, Ictinogomphus rapax, Cratilla lineata, Lathrecista asiatica, Neurothemis tullia, Tholymis tillarga and Copera ciliata were strictly found at Saleh River implicating their preference for smaller, slow moving and polluted river with floating microphytes and few other surrounding plant species. Neurobasis chinensis and Vestalis gracilis were only found in open, undisturbed, fast flowing waters of Setul and Serdang rivers. Generally the adults perched on marginal vegetation as well as those on the river bank areas.
文摘Focusing on the 18 counties along “One River and Two Tributaries” region, and based on the data from China 3nl, 4th and 5th population censuses, this article has analyzed the time and spatial changing patterns of the population in this region. The analyses show that since the 3nl population census, total population, average age and total birth rate have all changed considerably: ① Total population has grown, fast, with most counties' annual average growth rate of more than 10. ② In terms of the region's average age, in 2000 the age in the 18 counties is younger than 30 years old. ③ Compared with the 3nl population census, labor force by the 5th census is much younger. ④ Countermeasures are proposed to control population by controlling birth rate as the result of the local resident's quality improvement by education.
文摘Focusing on the region of Yarlung Zangbo River and the middle reaches of itstwo tributaries of Nianchu River and Lhasa River in Tibet (Hereafter referred to as the 'One Riverand Two Tributaries' region), and based on the data from China 3rd, 4th and5th population censuses,the article has analyzed change patterns of this region' s labor force. Major findings from thestudy are summarized as follows; (1) Compared with the data from the 3rd census, labor forcepopulation in 2000 has increased significantly. (2) Children dependency coefficient has dropped,while old people dependency coefficient has changed very slightly with an increase of 0. 047% only.(3) Compared 2000 with 1982, illiteracy and semi-illiteracy rate of the population above 15 yearsold have decreased significantly by 30. 69 percentage points, but still higher than the nationalaverage. (4) Women' s illiteracy rate has dropped faster than men's, but up to 2000 it was generallyquite high. The upgrading of the entire population's overall quality has a long way to go.
