Chronic disease is an important factor that affect the health of elderly people. We analyzed the 2006 and 2010 data from the Chinese Urban and Rural Elderly Population Surveys, which are nationally representative surv...Chronic disease is an important factor that affect the health of elderly people. We analyzed the 2006 and 2010 data from the Chinese Urban and Rural Elderly Population Surveys, which are nationally representative surveys of elderly people aged 60 years and above. We found that there existed a typical power-law distribution for the rates of different numbers of chronic diseases among elderly Chinese people. A Kolmogorov-Smirnov test indicated that the result was robust, and the power exponents were approximately ?2.5. In addition, a paired t-test was conducted, which demonstrated that the rates of different numbers of chronic diseases did not have significant urban-rural differences, time differences or gender differences.展开更多
Accounting for the missile autopilot as second-order dynamics, an observer-based guidance law is designed based on the dynamic surface control method. Some first-order low-pass filters are introduced into the design p...Accounting for the missile autopilot as second-order dynamics, an observer-based guidance law is designed based on the dynamic surface control method. Some first-order low-pass filters are introduced into the design process to avoid the occurrence of high-order derivatives of the line of sight angle in the expression of guidance law such that it can be implemented in practical applications. The proposed guidance law is effective in compensating the bad influence of the autopilot lag on guidance accuracy. In the simulations of intercepting non maneuvering targets, targets with step acceleration, and targets with sinusoidal acceleration respectively, the guidance law is compared with the adaptive sliding mode guidance law in the presence of missile autopilot lag. The simulation results show that the proposed guidance law is able to guide a missile to accurately intercept a maneuvering target, even if it escapes in a great and fast maneuver and the autopilot has a relatively large lag.展开更多
There have emerged ample literature about the Second Law analysis of extraterrestrial and terrestrial solar radiation consequent to the pioneer works by R. Petela and D. C. Spanner, of which most are irrelevant to the...There have emerged ample literature about the Second Law analysis of extraterrestrial and terrestrial solar radiation consequent to the pioneer works by R. Petela and D. C. Spanner, of which most are irrelevant to the frequency distribution of solar radiation. Since the Second Law analysis was introduced to the fields like photovoltaic and photosynthesis, rendering a need for a method closely related to solar radiation spectrum, some authors created wavelength dependent dilute factots to take the various influence of atmosphere on the frequency distribution into consideration. Because of the complexity of the influence on different frequency, it is not convenient and accurate enough to practically apply the present exergy theories of diluted solar radiation to real solar exergy systems at the surface of the earth. This paper shows a numerical method of Second Law analysis in dealing with the cases of diluted solar irradiance on the earth, based on the observed spectra of global direct and diffuse展开更多
This paper had started its words from the hot current Umbrella Movement in Hongkong, with putting forward the questions that ＂ What is the democracy？ ＂ and ＂ How should the democracy develop？ ＂ . And then, it ha...This paper had started its words from the hot current Umbrella Movement in Hongkong, with putting forward the questions that ＂ What is the democracy？ ＂ and ＂ How should the democracy develop？ ＂ . And then, it had reviewed the historical development of the concept of democracy, on that basis, it had explored the socialist democratic system in China and analyzed the dilemmas in the construction of socialist democracy. And it gave the responses to questions in the beginning of the article and explained the reasons in details. At the last, some notes on the construction of democracy in China＇ s journey toward rule of law were written in this article.展开更多
Editor's Note: In recent years, China's public security organs have firmly implanted the idea of enforcing the law in the interests of the people and adhered to the principle of enforcing the law strictly, imp...Editor's Note: In recent years, China's public security organs have firmly implanted the idea of enforcing the law in the interests of the people and adhered to the principle of enforcing the law strictly, impartially and in a civilized manner and dealing flows at all kinds of criminal activities. They have achieved fruitful results in protecting the lawful rights and interests of the people and in safeguarding and protecting human rights. To know such achievements, our staff reporter interviewed Tian Qiyu, executive vice-minister of public security.展开更多
文摘Chronic disease is an important factor that affect the health of elderly people. We analyzed the 2006 and 2010 data from the Chinese Urban and Rural Elderly Population Surveys, which are nationally representative surveys of elderly people aged 60 years and above. We found that there existed a typical power-law distribution for the rates of different numbers of chronic diseases among elderly Chinese people. A Kolmogorov-Smirnov test indicated that the result was robust, and the power exponents were approximately ?2.5. In addition, a paired t-test was conducted, which demonstrated that the rates of different numbers of chronic diseases did not have significant urban-rural differences, time differences or gender differences.
基金Sponsored by the Natural Science Foundation of China(Grant No.61174203)the Program for New Century Excellent Talents in University(Grant No.NCET-08-0153)the Aviation Science Foundation of China(Grant No.20110177002)
文摘Accounting for the missile autopilot as second-order dynamics, an observer-based guidance law is designed based on the dynamic surface control method. Some first-order low-pass filters are introduced into the design process to avoid the occurrence of high-order derivatives of the line of sight angle in the expression of guidance law such that it can be implemented in practical applications. The proposed guidance law is effective in compensating the bad influence of the autopilot lag on guidance accuracy. In the simulations of intercepting non maneuvering targets, targets with step acceleration, and targets with sinusoidal acceleration respectively, the guidance law is compared with the adaptive sliding mode guidance law in the presence of missile autopilot lag. The simulation results show that the proposed guidance law is able to guide a missile to accurately intercept a maneuvering target, even if it escapes in a great and fast maneuver and the autopilot has a relatively large lag.
文摘There have emerged ample literature about the Second Law analysis of extraterrestrial and terrestrial solar radiation consequent to the pioneer works by R. Petela and D. C. Spanner, of which most are irrelevant to the frequency distribution of solar radiation. Since the Second Law analysis was introduced to the fields like photovoltaic and photosynthesis, rendering a need for a method closely related to solar radiation spectrum, some authors created wavelength dependent dilute factots to take the various influence of atmosphere on the frequency distribution into consideration. Because of the complexity of the influence on different frequency, it is not convenient and accurate enough to practically apply the present exergy theories of diluted solar radiation to real solar exergy systems at the surface of the earth. This paper shows a numerical method of Second Law analysis in dealing with the cases of diluted solar irradiance on the earth, based on the observed spectra of global direct and diffuse
文摘This paper had started its words from the hot current Umbrella Movement in Hongkong, with putting forward the questions that ＂ What is the democracy？ ＂ and ＂ How should the democracy develop？ ＂ . And then, it had reviewed the historical development of the concept of democracy, on that basis, it had explored the socialist democratic system in China and analyzed the dilemmas in the construction of socialist democracy. And it gave the responses to questions in the beginning of the article and explained the reasons in details. At the last, some notes on the construction of democracy in China＇ s journey toward rule of law were written in this article.
文摘Editor's Note: In recent years, China's public security organs have firmly implanted the idea of enforcing the law in the interests of the people and adhered to the principle of enforcing the law strictly, impartially and in a civilized manner and dealing flows at all kinds of criminal activities. They have achieved fruitful results in protecting the lawful rights and interests of the people and in safeguarding and protecting human rights. To know such achievements, our staff reporter interviewed Tian Qiyu, executive vice-minister of public security.
