In terms of single-atom induced dipole moment by Lewenstein model, we present the macroscopic high-order harmonic generation from mixed He and Ne gases with different mixture ratios by solving three-dimensional Maxwel...In terms of single-atom induced dipole moment by Lewenstein model, we present the macroscopic high-order harmonic generation from mixed He and Ne gases with different mixture ratios by solving three-dimensional Maxwell＇s equation of harmonic field. And then we show the validity of mixture formulation by Wagner et al. [Phys. Rev. A 76 （2007） 061403（R）] in macroscopic response level. Finally, using/east squares fitting we retrieve the electron return time of short trajectory by formulation in Kanai et al. [Phys. Rev. Lett. 98 （2007） 153904] when the gas jet is put after the laser focus.展开更多
Athetis lepigone Moschler is a new kind of insect pest occurring in summer corn production areas. By investigation, it was found especially serious in straw returning fields. In this paper, its damage status was inves...Athetis lepigone Moschler is a new kind of insect pest occurring in summer corn production areas. By investigation, it was found especially serious in straw returning fields. In this paper, its damage status was investigated in straw returning and chemical controlled fields, respectively. The results showed that the rate of damaged plants was 82% and the maximum pest number per 100 plants was 88 heads in the straw returning fields without chemical control. The application of herbicides and pesticides had no significant effects on occurrence quantity and damage rate, but the pest number per 100 plants decreased a little compared to the fields without chemical control. In the surer er maize fields without straw returning, the application of herbicides and pesticides could significantly decrease the damage of Athetis lepigone, the rate of damaged plants was 20%, and the pest number per 100 plants was 6.展开更多
Performance of hospitality stocks and financial ratios are relatively well discussed topics in hospitality finance. The current study contributes to the body of knowledge by attempting to identify if certain groups of...Performance of hospitality stocks and financial ratios are relatively well discussed topics in hospitality finance. The current study contributes to the body of knowledge by attempting to identify if certain groups of hospitality stocks continually outperform market and if selected financial ratios can predict excess returns. Hospitality stocks betas were computed and most recent five-year annual returns were utilized for analysis. Study used Jensen＇s alpha to determine excess returns for various hospitality segments studied. Six major ratios were operationalized to determine the predictability of excess returns in hospitality stocks. Overall, the excess returns in hospitality company stocks were positive but no significance was found with an exception of one year. Out of six selected ratios, cash flow per share was determined to have significant predictive power for excess returns. In conclusions, study provides important implications for the investors and industry decision makers.展开更多
This year marks the40th anniversary of China’s opening up to the world.One of the key decisions during the early period after opening-up was the restoration of the national college entrance exam.As of today,China has...This year marks the40th anniversary of China’s opening up to the world.One of the key decisions during the early period after opening-up was the restoration of the national college entrance exam.As of today,China has produced nearly100million college students and6million overseas students,which provided a solid human resource background for China’s opening-up and economic growth.展开更多
Stapleton Roy,U.S.ambassador to China,expressed thanks to the Chinese govemment for the cooper-ation and assistance it extended to the U.S.recovery team.He said the cooperative effort of the two coun-tries symbolized ...Stapleton Roy,U.S.ambassador to China,expressed thanks to the Chinese govemment for the cooper-ation and assistance it extended to the U.S.recovery team.He said the cooperative effort of the two coun-tries symbolized that"we continue to cherish the emories of those who gave their lives so that we today can live in a better,safer world."展开更多
The women＇s liberation movement in China started after the first opium war and it took shape with the aim of protecting the race and salvaging the country. Doubtlessly, the emergence of modern feminism opened the pre...The women＇s liberation movement in China started after the first opium war and it took shape with the aim of protecting the race and salvaging the country. Doubtlessly, the emergence of modern feminism opened the precedent in the theory of women＇s liberation in China and exerted a profound and far-reaching influence on women＇s liberation afterwards. But we must face up to the fact that there was some traps or misunderstanding of modern feminism, which were unfavorable for realizing women＇s rights and such influence was long, so much so that till today we are still seeing its existence. It is, therefore, necessary to have a full reflection of modem feminism, unveil the original meaning of women＇s rights and make women＇s rights return to human rights in order to make the development of women＇s fights continue.展开更多
针对蜂窝移动通信定位技术中常见的非视距传播(NLOS)问题,提出了一种利用来波信号强度和来波方位角测量值的联合条件概率判决NLOS的算法(JCPDS-RA,joint conditional probability decision scheme with RSS and AOA),并将其与数据融合...针对蜂窝移动通信定位技术中常见的非视距传播(NLOS)问题,提出了一种利用来波信号强度和来波方位角测量值的联合条件概率判决NLOS的算法(JCPDS-RA,joint conditional probability decision scheme with RSS and AOA),并将其与数据融合定位技术相结合,提高定位精度。推导了NLOS环境下RSS和AOA的条件概率密度模型,给出了JCPDS-RA算法和数据融合流程图,并进行了仿真实验,结果表明,该算法有效地提高了定位精度并有一定的普适性。展开更多
基金Supported by the National Natural Science Foundation of China under Grant No. 10674112the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No. 20096203110001+1 种基金the Foundation of Center of Theoretical Nuclear Physics of National Laboratory of Heavy Ion Accelerator of LanzhouFoundation of Northwest Normal University under Grant No. NWNUKJCXGC-03-62
文摘In terms of single-atom induced dipole moment by Lewenstein model, we present the macroscopic high-order harmonic generation from mixed He and Ne gases with different mixture ratios by solving three-dimensional Maxwell＇s equation of harmonic field. And then we show the validity of mixture formulation by Wagner et al. [Phys. Rev. A 76 （2007） 061403（R）] in macroscopic response level. Finally, using/east squares fitting we retrieve the electron return time of short trajectory by formulation in Kanai et al. [Phys. Rev. Lett. 98 （2007） 153904] when the gas jet is put after the laser focus.
基金Supported by China Agricultural Research System ( CARS-02)
文摘Athetis lepigone Moschler is a new kind of insect pest occurring in summer corn production areas. By investigation, it was found especially serious in straw returning fields. In this paper, its damage status was investigated in straw returning and chemical controlled fields, respectively. The results showed that the rate of damaged plants was 82% and the maximum pest number per 100 plants was 88 heads in the straw returning fields without chemical control. The application of herbicides and pesticides had no significant effects on occurrence quantity and damage rate, but the pest number per 100 plants decreased a little compared to the fields without chemical control. In the surer er maize fields without straw returning, the application of herbicides and pesticides could significantly decrease the damage of Athetis lepigone, the rate of damaged plants was 20%, and the pest number per 100 plants was 6.
文摘Performance of hospitality stocks and financial ratios are relatively well discussed topics in hospitality finance. The current study contributes to the body of knowledge by attempting to identify if certain groups of hospitality stocks continually outperform market and if selected financial ratios can predict excess returns. Hospitality stocks betas were computed and most recent five-year annual returns were utilized for analysis. Study used Jensen＇s alpha to determine excess returns for various hospitality segments studied. Six major ratios were operationalized to determine the predictability of excess returns in hospitality stocks. Overall, the excess returns in hospitality company stocks were positive but no significance was found with an exception of one year. Out of six selected ratios, cash flow per share was determined to have significant predictive power for excess returns. In conclusions, study provides important implications for the investors and industry decision makers.
文摘This year marks the40th anniversary of China’s opening up to the world.One of the key decisions during the early period after opening-up was the restoration of the national college entrance exam.As of today,China has produced nearly100million college students and6million overseas students,which provided a solid human resource background for China’s opening-up and economic growth.
文摘Stapleton Roy,U.S.ambassador to China,expressed thanks to the Chinese govemment for the cooper-ation and assistance it extended to the U.S.recovery team.He said the cooperative effort of the two coun-tries symbolized that"we continue to cherish the emories of those who gave their lives so that we today can live in a better,safer world."
文摘The women＇s liberation movement in China started after the first opium war and it took shape with the aim of protecting the race and salvaging the country. Doubtlessly, the emergence of modern feminism opened the precedent in the theory of women＇s liberation in China and exerted a profound and far-reaching influence on women＇s liberation afterwards. But we must face up to the fact that there was some traps or misunderstanding of modern feminism, which were unfavorable for realizing women＇s rights and such influence was long, so much so that till today we are still seeing its existence. It is, therefore, necessary to have a full reflection of modem feminism, unveil the original meaning of women＇s rights and make women＇s rights return to human rights in order to make the development of women＇s fights continue.
文摘针对蜂窝移动通信定位技术中常见的非视距传播(NLOS)问题,提出了一种利用来波信号强度和来波方位角测量值的联合条件概率判决NLOS的算法(JCPDS-RA,joint conditional probability decision scheme with RSS and AOA),并将其与数据融合定位技术相结合,提高定位精度。推导了NLOS环境下RSS和AOA的条件概率密度模型,给出了JCPDS-RA算法和数据融合流程图,并进行了仿真实验,结果表明,该算法有效地提高了定位精度并有一定的普适性。
