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关于《生物》《生理卫生》《人口科学》等学科与性教育的衔接
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作者 赵国文 《生物学教学》 北大核心 2001年第8期45-45,共1页
关键词 《生物》 《生理卫生》 《人口科学》 性教育 教学
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Science and the practice of cardiovascular medicine in the geriatric population 被引量:1
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作者 Nanette K Wenger 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2011年第2期67-71,共5页
1 Why is the demograpy important? In the half century 2000-2050,there will be a virtual tsunami of aging in the United States.The anticipated increase in the population older than age 65 is 140%,and for the population... 1 Why is the demograpy important? In the half century 2000-2050,there will be a virtual tsunami of aging in the United States.The anticipated increase in the population older than age 65 is 140%,and for the population older than age 85,389%.More than half of the current U.S.population can anticipate living to age 80,with a contemporary life expectancy at age 75 of 11 years,and at age 85 of 6 years. 展开更多
关键词 cardiovascular medicine the aged clinical trials
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The Dual Model for Tourism Resource Productivity Improvement
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作者 Sun Kun Min Qingwen Cheng Shengkui 《Chinese Journal of Population,Resources and Environment》 2011年第1期78-84,共7页
For natural resource science, resource productivity studying is an important subject. But researches on tourism resource productivity are limited. The most significant influencing factor on tourism resource productivi... For natural resource science, resource productivity studying is an important subject. But researches on tourism resource productivity are limited. The most significant influencing factor on tourism resource productivity is the potential market scale of tourist locations, and second most important influencing factor is the resource endowment. Regional urban population is significantly correlated with region tourist numbers, being the decisive factor of region potential tour market scale. In tourism development, the dual model should be adopted: on one hand to enhance tour spot attractiveness, on the other hand to cultivate the potential market by improving urbanization level and other means. In the situation of tourism development fever spreading, the dual model for improving tourism productivity helps to avoid the "Great Leap Forward" which means that too rapid tourism construction divorces from actual market demand. 展开更多
关键词 tourism resource productivity the dual model potential market scale tourism resource endowment market cultivation
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A study of nonlinear age-structured population models 被引量:2
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作者 Syed Tauseef Mohyud-Din A. Waheed M. M. Ra.shidi 《International Journal of Biomathematics》 2016年第6期211-223,共13页
This paper presents a novel analysis for the solution of nonlinear age-structured prob- lem which is of extreme importance in biological sciences. The presented model is very useful but quite complicated. Modified var... This paper presents a novel analysis for the solution of nonlinear age-structured prob- lem which is of extreme importance in biological sciences. The presented model is very useful but quite complicated. Modified variational iteration method (MVIM) coupled with auxiliary parameter is used to cope with the complexity of the model which subse- quently shows better results as compared to some existing results available in literature. Furthermore, an appropriate way is used for the identification of auxiliary parameter by means of residual function. Numerical examples are presented for the analysis of the pro- posed algorithm. Graphical results along with the discussions re-confirm the efficiency of proposed algorithm. The work proposes a new algorithm where He's polynomials and an auxiliary parameter are merged with correction functional. The suggested scheme is implemented on nonlinear age-structured population models. Graphs are plotted for the residual function that reflects the accuracy and convergence of the presented algorithm. 展开更多
关键词 Age-structured population models nonlinear problems modified variationaliteration method auxiliary parameter correction functional.
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