The world situation is experiencing profound and complex changes. With the further deepening of economic globalization, various countries with interwoven interests are becoming increasingly interdependent and interrel...The world situation is experiencing profound and complex changes. With the further deepening of economic globalization, various countries with interwoven interests are becoming increasingly interdependent and interrelated. A large number of big developing countries are rising, adding fresh rich elements to the trend of development toward multi-polarity.展开更多
We propose an efficient method for the generation of an isolated attosecond pulse from the asymmetric molecular ions HeH^2＋ by adding a half-cycle-like field （HCLF） to the fundamental driving laser field. The high-...We propose an efficient method for the generation of an isolated attosecond pulse from the asymmetric molecular ions HeH^2＋ by adding a half-cycle-like field （HCLF） to the fundamental driving laser field. The high-order harmonic generation （HHG） is investigated by numerically sowing the time-dependent Schrodinger equation. By performing the time-frequency distributions and the electronic wave packet probability densities, we find that the optimizing combined field is not only useful for extending the HHG cutoff, but also for simplifying the recombination channels through controlling the electron localization. In addition, by adjusting the intensity of the HCLF, a dominant short quantum path is selected to contribute the HHG spectrum. As a result, a 75-as isolated attosecond pulse is obtained by superposing a proper range of the harmonics.展开更多
Human activities have caused the exchange of species among different parts of the world.When introduced species become naturalized and invasive,they may cause great negative impacts on the environment and human societ...Human activities have caused the exchange of species among different parts of the world.When introduced species become naturalized and invasive,they may cause great negative impacts on the environment and human societies,and pose significant threats to biodiversity and ecosystem structure.Knowledge on phylogenetic relatedness between native and non-native species and among non-native species at different stages of species invasion may help for better understanding the drivers of species invasion.Here,I analyze a comprehensive data set including both native and non-native angiosperm species in China to determine phylogenetic relatedness of introduced species across a full invasion continuum(from introduction through naturalization to invasion).This study found that(1) introduced plants are a phylogenetically clustered subset of overall(i.e.native plus non-native) angiosperm flora,(2) naturalized plants are a phylogenetically clustered subset of introduced plants,and(3) invasive plants are a phylogenetically clustered subset of naturalized plants.These patterns hold regardless of spatial scales examined(i.e.national versus provincial scale) and whether basal-or tip-weighted metric of phylogenetic relatedness is considered.These findings are consistent with Darwin's preadaptation hypothesis.展开更多
Invasive species may pose significant threats to biodiversity and ecosystem structure and functioning.The number of introduced species that have become invasive is substantial and is rapidly increasing.Identifying pot...Invasive species may pose significant threats to biodiversity and ecosystem structure and functioning.The number of introduced species that have become invasive is substantial and is rapidly increasing.Identifying potentially invasive species and preventing their expansion are of critical importance in invasion ecology.Phylogenetic relatedness between invasive and native species has been used in predicting invasion success.Previous studies on the phylogenetic relatedness of plants at the transition from naturalization to invasion have shown mixed results,which may be because different methods were used in different studies.Here,I use the same method to analyze two comprehensive data sets from South Africa and China,using two phylogenetic metrics reflecting deep and shallow evolutionary histories,to address the question whether the probability of becoming invasive is higher for naturalized species distantly related to the native flora.My study suggests that the probability of becoming invasive is higher for naturalized species closely related to the native flora.The finding of my study is consistent with Darwin's preadaptation hypothesis.展开更多
At the beginning of this New Year of 2013, we are very pleased to present the English edition of the Journal of Integrative Medicine （JIM）, a PubMed-indexed, peer-reviewed, open-access journal on integrative medicin...At the beginning of this New Year of 2013, we are very pleased to present the English edition of the Journal of Integrative Medicine （JIM）, a PubMed-indexed, peer-reviewed, open-access journal on integrative medicine. The JIM is a continuation of the former Chinese-language journal, the Journal of Chinese Integrative Medicine （JCIM）, established in 2003 and published in Shanghai. Integrative medicine, grounded in patient-centered, evidence-based practice, incorporates the broad spectrum of complementary and alternative medicine （CAM） and includes acupuncture and traditional Chinese medicine, Ayurveda medicine, herbal medicine, homeopathy, nutrition, chiropractic, mind-body medicine, taichi, qigong, and meditation, among other professions. In the past two decades, CAM has become one of the fastest growing branches of health care. CAM now commands attention worldwide and is rapidly being integrated into conventional medicine. China is the country in the world that has great number of scientists doing clinical and research work on integrative medicine. With this new, English-language publication, we are committed to make JIM an international platform for high-quality CAM papers and an open forum in which the different professions and international scholarly communities can exchange views, share research and their clinical experience, discuss CAM education, and confer about issues and problems in our various disciplines and in CAM as a whole in order to promote integrative medicine.展开更多
JOURNAL OF CHINA ORDNANCE, an official journal sponsored by China Ordnance Society and published half-yearly, aims to presenting the latest developments and achievements of the academic circles specializing in the fie...JOURNAL OF CHINA ORDNANCE, an official journal sponsored by China Ordnance Society and published half-yearly, aims to presenting the latest developments and achievements of the academic circles specializing in the field of ordnance science and technology. It provides a展开更多
Tricyclic compound 6 was synthesized form compound 1 through sis steps, thus preblem of the stereochemistry of C2α-H being solved. The stereochemistry for introducing hydroxy groups at C3β and C4α positions in com...Tricyclic compound 6 was synthesized form compound 1 through sis steps, thus preblem of the stereochemistry of C2α-H being solved. The stereochemistry for introducing hydroxy groups at C3β and C4α positions in compound 1 was also described.展开更多
Sustained and profound aridization process in north west China in Tertiary and Quaternary period and time of mankind history are discussed. The rain creased function of 3 set high mountain condensation systems in nort...Sustained and profound aridization process in north west China in Tertiary and Quaternary period and time of mankind history are discussed. The rain creased function of 3 set high mountain condensation systems in north west China is recognized once more. A sandstorm happened on 20th March 2002 in Alasan and Ejinaqi areas was very strong and arrived in Japan and Korea. For saving Alasan area from sandstorm a way of introducing sea water from Bohai to Alasan has been proposed. Four problems are replied in this paper. It is concluded that introducing sea water from Bohai to west China is the best way for sustainable development of west China.展开更多
文摘The world situation is experiencing profound and complex changes. With the further deepening of economic globalization, various countries with interwoven interests are becoming increasingly interdependent and interrelated. A large number of big developing countries are rising, adding fresh rich elements to the trend of development toward multi-polarity.
基金Supported by the National Natural Science Foundation of China under Grant No 11404204the Key Project of the Ministry of Education of China under Grant No 211025+1 种基金the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20111404120004the Natural Science Foundation for Young Scientists of Shanxi Province under Grant No 2009021005
文摘We propose an efficient method for the generation of an isolated attosecond pulse from the asymmetric molecular ions HeH^2＋ by adding a half-cycle-like field （HCLF） to the fundamental driving laser field. The high-order harmonic generation （HHG） is investigated by numerically sowing the time-dependent Schrodinger equation. By performing the time-frequency distributions and the electronic wave packet probability densities, we find that the optimizing combined field is not only useful for extending the HHG cutoff, but also for simplifying the recombination channels through controlling the electron localization. In addition, by adjusting the intensity of the HCLF, a dominant short quantum path is selected to contribute the HHG spectrum. As a result, a 75-as isolated attosecond pulse is obtained by superposing a proper range of the harmonics.
文摘Human activities have caused the exchange of species among different parts of the world.When introduced species become naturalized and invasive,they may cause great negative impacts on the environment and human societies,and pose significant threats to biodiversity and ecosystem structure.Knowledge on phylogenetic relatedness between native and non-native species and among non-native species at different stages of species invasion may help for better understanding the drivers of species invasion.Here,I analyze a comprehensive data set including both native and non-native angiosperm species in China to determine phylogenetic relatedness of introduced species across a full invasion continuum(from introduction through naturalization to invasion).This study found that(1) introduced plants are a phylogenetically clustered subset of overall(i.e.native plus non-native) angiosperm flora,(2) naturalized plants are a phylogenetically clustered subset of introduced plants,and(3) invasive plants are a phylogenetically clustered subset of naturalized plants.These patterns hold regardless of spatial scales examined(i.e.national versus provincial scale) and whether basal-or tip-weighted metric of phylogenetic relatedness is considered.These findings are consistent with Darwin's preadaptation hypothesis.
文摘Invasive species may pose significant threats to biodiversity and ecosystem structure and functioning.The number of introduced species that have become invasive is substantial and is rapidly increasing.Identifying potentially invasive species and preventing their expansion are of critical importance in invasion ecology.Phylogenetic relatedness between invasive and native species has been used in predicting invasion success.Previous studies on the phylogenetic relatedness of plants at the transition from naturalization to invasion have shown mixed results,which may be because different methods were used in different studies.Here,I use the same method to analyze two comprehensive data sets from South Africa and China,using two phylogenetic metrics reflecting deep and shallow evolutionary histories,to address the question whether the probability of becoming invasive is higher for naturalized species distantly related to the native flora.My study suggests that the probability of becoming invasive is higher for naturalized species closely related to the native flora.The finding of my study is consistent with Darwin's preadaptation hypothesis.
文摘At the beginning of this New Year of 2013, we are very pleased to present the English edition of the Journal of Integrative Medicine （JIM）, a PubMed-indexed, peer-reviewed, open-access journal on integrative medicine. The JIM is a continuation of the former Chinese-language journal, the Journal of Chinese Integrative Medicine （JCIM）, established in 2003 and published in Shanghai. Integrative medicine, grounded in patient-centered, evidence-based practice, incorporates the broad spectrum of complementary and alternative medicine （CAM） and includes acupuncture and traditional Chinese medicine, Ayurveda medicine, herbal medicine, homeopathy, nutrition, chiropractic, mind-body medicine, taichi, qigong, and meditation, among other professions. In the past two decades, CAM has become one of the fastest growing branches of health care. CAM now commands attention worldwide and is rapidly being integrated into conventional medicine. China is the country in the world that has great number of scientists doing clinical and research work on integrative medicine. With this new, English-language publication, we are committed to make JIM an international platform for high-quality CAM papers and an open forum in which the different professions and international scholarly communities can exchange views, share research and their clinical experience, discuss CAM education, and confer about issues and problems in our various disciplines and in CAM as a whole in order to promote integrative medicine.
文摘JOURNAL OF CHINA ORDNANCE, an official journal sponsored by China Ordnance Society and published half-yearly, aims to presenting the latest developments and achievements of the academic circles specializing in the field of ordnance science and technology. It provides a
文摘Tricyclic compound 6 was synthesized form compound 1 through sis steps, thus preblem of the stereochemistry of C2α-H being solved. The stereochemistry for introducing hydroxy groups at C3β and C4α positions in compound 1 was also described.
文摘Sustained and profound aridization process in north west China in Tertiary and Quaternary period and time of mankind history are discussed. The rain creased function of 3 set high mountain condensation systems in north west China is recognized once more. A sandstorm happened on 20th March 2002 in Alasan and Ejinaqi areas was very strong and arrived in Japan and Korea. For saving Alasan area from sandstorm a way of introducing sea water from Bohai to Alasan has been proposed. Four problems are replied in this paper. It is concluded that introducing sea water from Bohai to west China is the best way for sustainable development of west China.
