Based on theories of protective forests and landscape ecology, the reasonableness of structures and patterns of shelterbelt system at Beizang Town, Daxing County, Beijing were analyzed and assessed from the two scales...Based on theories of protective forests and landscape ecology, the reasonableness of structures and patterns of shelterbelt system at Beizang Town, Daxing County, Beijing were analyzed and assessed from the two scales of forest belts and networks, by integrating uses of field investigation, GIS and RS techniques. Results showed that the existent main belt (3-12 m in width) was too narrow, while the assistant belt (3-27.1 m in width) was too wide; the species composition of the existent shelterbelts was single, and the structures and patterns of the shelterbelt system were unreasonable. It is suggested that the structure of the main and the assistant belts should be changed, such as increasing the width of main belts, decreasing the width of assistant belt, and planting more mixed species, and the pattern with arbores in the middle and shrubs in the sides of belts could be taken into account. For the landscape structure of forest network after regenerating or reconstruction, the grid number of closed network should be 13 per km2 and the minimum number of belts should be 34 per km2. This study also testified that integrating GIS and remote technique with landscape ecology could provide an effective method for reasonable reconstruction of the structures and patterns of shelterbelts system.展开更多
The water conservation capacities of main forests in Beijing,China were estimated through the quantitative analysis.Various methods developed in published papers on forest hydrology were employed.The forests in Huairo...The water conservation capacities of main forests in Beijing,China were estimated through the quantitative analysis.Various methods developed in published papers on forest hydrology were employed.The forests in Huairou,Yanqing,Miyun,Mentougou and Fangshan districts are the main contributors to water conservation（the cumulative ratio reaches 65%）,and the forests in Tongzhou,Chaoyang,Shunyi and Daxing districts have the highest water conservation capacity（3000 m3/ha）.Altitude and slope are the key factors to affect the water conservation capacity.The forests located in Plain Area,Hilly Area,Low Mountain,and Middle Mountain contributes 27%,28%,24% and 21% of the conserved water,respectively.The water conservation capacity of forests in Plain Area（2 948 m3/ha）,is superior to the forests in other regions.And the forests situated on Flat Slope,Moderate Slope and Gentle Slope constitute the largest proportion（nearly 93%） of water conservation,while the forests on Flat Slope has the highest water conservation capacity（2 797 m3/ha）,and the forest on Steep slope has the lowest water conservation capacity（948 m3/ha）.展开更多
We investigated characteristics （scales and composition） of soil seed banks at eight study sites in the rocky mountain region of Beijing by seed identification and germination monitoring. We also surveyed the vegeta...We investigated characteristics （scales and composition） of soil seed banks at eight study sites in the rocky mountain region of Beijing by seed identification and germination monitoring. We also surveyed the vegetation communities at the eight study sites to explore the role of soil seed banks in vegetation restoration. The storage capacity of soil seed banks at the eight sites ranked from 766.26 to 2461.92 seeds·m？2. A total of 23 plant species were found in soil seed banks, of which 63–80% of seeds were herbs in various soil layers and 60% of seeds were located in the soil layer at 0–5 cm depth. Biodiversity indices indicated clear differences in species diversity of soil seed banks among different plant communities. The species composition of aboveground vegetation showed low similarity with that based on soil seed banks. In the aboveground plant community, the afforestation tree species showed high importance values. The plant species originating from soil seed banks represented natural regeneration, which also showed relatively high importance values. This study suggests that in the rocky mountain region of Beijing the soil seed banks played a key role in the transformation from pure plantation forest to near-natural forest, promoting natural ecological processes, and the role of the seed banks in vegetation restoration was important to the improvement of ecological restoration methods.展开更多
A three-year aeropalynological study was carried out in the month of August for each of the three years 2005, 2006 and 2007 in the Beijing Olympic Park. A total of 19550 pollen grains were counted （15057 grains in 20...A three-year aeropalynological study was carried out in the month of August for each of the three years 2005, 2006 and 2007 in the Beijing Olympic Park. A total of 19550 pollen grains were counted （15057 grains in 2005, 2717 in 2006 and 1776 in 2007） for the following taxa： Gramineae, Chenopodiaceae, Humulus L., Artemisia L., Ambrosia L. and Pinus L. The analysis indicated that in the three consecutive years of 2005-007, airborne pollen types and daily number of pollen in August in the Beijing Olympic Park were closely related to environmental change and vegetation composition. The daily variations of airborne pollen displayed similar patterns in August in each of the three years, which were affected positively by periods of daily sunshine, negatively by daily relative humidity and daily precipitation. Continuously high daily temperatures and stable daily wind speeds seemed to have little effect on the fluctuation of airborne pollen.展开更多
According to intensity distribution of the synchrotron radiation source focused by a toroidal mirror at the Beijing synchrotron radiation biological macromolecule station, theoretical modeling of the Beijing synchrotr...According to intensity distribution of the synchrotron radiation source focused by a toroidal mirror at the Beijing synchrotron radiation biological macromolecule station, theoretical modeling of the Beijing synchrotron radiation source is developed for capillary optics. Using this theoretical modeling, the influences of the configuration curve of the polycapillary X-ray lens on transmission efficiency and working distance are analyzed. The experimental results of the transmission efficiency and working distance at the biological macromolecule station are in good agreement with the theoretical results.展开更多
Objective To understand the perception for the use of cataract surgical services in a population acceptors and non-acceptors of cataract surgery in urban Beijing. Methods From a community-based screening program a to...Objective To understand the perception for the use of cataract surgical services in a population acceptors and non-acceptors of cataract surgery in urban Beijing. Methods From a community-based screening program a total of 158 patients with presenting visual acuity of less than 6/18 on either eye due to age-related cataract were informed about the possibility of surgical treatment. These patients were interviewed and re-examined 36 to 46 months after initial screening. The main reasons for not accepting surgery were obtained using a questionnaire. Vision function and vision-related quality of life scores were assessed in those who received and did not receive surgery. Results At the follow-up examination 116 of the 158 patients were available and 36 （31.0%） had undergone cataract surgery. Cases who chose surgery had higher education level than those who did not seek surgery （OR=2.64, 95% CI： 1.08-6.63, P=0.02）. There were no significant differences in vision function （P=0.11） or quality of life scores （P=0.16） between the surgery group and the non-surgery group. Main reasons for not having surgery included no perceived need （50.0%）, feeling of being ＂too old＂ （19.2%）, and worry about the quality of surgery （9.6%）. Cost was seeking surgery. cited by 1 （1.9%） subject as the main reason for not展开更多
The evaluation of ecosystem health has become one of the main research topics of ecosystem science, thus more and more assessment methods and frameworks have been put forward in recent years. However, the attention pe...The evaluation of ecosystem health has become one of the main research topics of ecosystem science, thus more and more assessment methods and frameworks have been put forward in recent years. However, the attention people pay to ecosystem health is actually more about what the social functions the ecosystem affords, which depend on the integrity and maintenance of the ecosystem structure and function, and the intensity of disturbance from outside. Accordingly, this research commenced from three main aspects, selected the evaluation indices, and then established the Evaluation Index System of Beijing Forest Ecosystem Health （EIS-BFEH）. In the EIS-BFEH, each of the three foundations contained an easily-operated and standard sub-index system, which compounded the specific natural and social conditions of Beijing and was concrete enough to measure and evaluate. Then with the method of the Analytical Hierarchy Process （AHP）, the comprehensive index （CI） could be obtained, which represented the health of the forest ecosystem. As a case study, the forest ecosystems in the Badaling area were sampled, evaluated, compared and ranked by use of the EIS-BFEH. The result show that the health of natural forests is much better than that of plantations in the Badaling forest center： the average comprehensive index of the former is 7.9, while the latter is only 6.6. From the results, it could also be found that there are nine units in the healthy state, two units in the subhealthy state, and only one unit of Robiniapseudoacacia in the morbid state.展开更多
The 1st International Conference on Data-driven Knowledge Discovery： When Data Science Meets Information Science took place at the National Science Library （NSL）, Chinese Academy of Sciences （CAS） in Beijing from...The 1st International Conference on Data-driven Knowledge Discovery： When Data Science Meets Information Science took place at the National Science Library （NSL）, Chinese Academy of Sciences （CAS） in Beijing from June 19 till June 22, 2016. The Conference was opened by NSL Director Xiangyang Huang, who placed the event within the goals of the Library, and lauded the spirit of intemational collaboration in the area of data science and knowledge discovery. The whole event was an encouraging success with over 370 registered participants and highly enlightening presentations. The Conference was organized by the Journal of Data andlnformation Science （JDIS） to bring the Joumal to the attention of an international and local audience.展开更多
This paper reports that at a newly constructed small-angle x-ray scattering station of Beijing Synchrotron Radia- tion Facility, the topological shape of ligand-free bovine serum albumin in solution has been investiga...This paper reports that at a newly constructed small-angle x-ray scattering station of Beijing Synchrotron Radia- tion Facility, the topological shape of ligand-free bovine serum albumin in solution has been investigated. An appropriate scattering curve is obtained and the calculated value of the gyration radius is 31.2~=t=0.25 ~_ （11=0.1 nm） which is co- incident with other ones＇ results. It finds that the low-resolution structure models obtained by making use of ab initio reconstruction methods are fitting the crystal structure of human serum albumin very well. All of these results perform the potential of the beamline to apply to structural biology studies. The characteristics, the defects, and the improving measures of the station in future are also discussed.展开更多
The x-ray compound lens is a novel refractive x-ray optical device. This paper reports the authors＇ recent research on a polymethyl methacrylate （PMMA） compound x-ray lens. Firstly the designing and LIGA fabricatio...The x-ray compound lens is a novel refractive x-ray optical device. This paper reports the authors＇ recent research on a polymethyl methacrylate （PMMA） compound x-ray lens. Firstly the designing and LIGA fabrication process for the PMMA compound x-ray lens are briefly described. Then, a method for theoretical analysis, as well as the experimental system for measurement is also introduced. Finally, the focusing spots for 8keV monochromatic x-rays by the PMMA compound x-ray lens are measured and analysed. According to the experimental results, it is concluded that the PMMA compound x-ray lens promises a good focusing performance under the high-energy x-rays.展开更多
Hao Jingfang's science-fiction novelette Folding Beijing was named the Best Novelette at the Hugos on August 21st, 2016. It is originally written in Chinese and gain recognition among foreign readers after being t...Hao Jingfang's science-fiction novelette Folding Beijing was named the Best Novelette at the Hugos on August 21st, 2016. It is originally written in Chinese and gain recognition among foreign readers after being translated into English. The fact that the translation put Chinese science-fiction on the international map again after the Hugo-award winning science-fiction The Three Body Problem written by Liu Cixin is an important event in Chinese science-fiction translation history. The contribution of Ken Liu's English version should not be neglected. This paper looks at the successful translation and its communication from the perspective of Multiple Causality of Translation proposed by Anthony Pym to probe into the kind of causation operative in the translation of Folding Beijing, including the material or initial cause, the final cause, the formal cause, and the efficient cause. Ken Liu's English version has made such a great success that a study of its formation and development may provide insights for home translators longing to help Chinese science-fiction reach more readers.展开更多
It had been found that Beijing ducks(BD) have a high level of HDL(70%), high LCAT but very low CETP activity and will not develop atherosclerosis on an atherogenic diet, suggesting that cholesterol ester is mainly car...It had been found that Beijing ducks(BD) have a high level of HDL(70%), high LCAT but very low CETP activity and will not develop atherosclerosis on an atherogenic diet, suggesting that cholesterol ester is mainly carried by HDL and metabolized through an HDL receptor pathway in the liver. However, evidence of this receptor′s existence in the liver is not yet complete. In this paper. the HDL receptor in BD liver has been studied. Our experiments showed : 1 ) ApoE-free 125 I-HDL could bind specifically to duck hepatic cell membrane with high affinity (Kd=9.6μg/ml) and was saturable (Bmax=8.9μg/mg cell membrane protein)at room temperature 2)Competitive inhibition studies with unlabelled duck, human, rat and chick HDL and duck apo AI and its liposomes formed with PC or DMPC could inhibit the binding of 125I-HDL to duck hepatic cell membranes, but LDL,apo E and their liposomes with PC or DMPC could not with the exception of duck LDL. 3) The receptor could recognize apo AI but not apo B or E. 4 ) Both phosphorase A2 and pronase could inhibit the binding activity. The above results give strong evidence for the existence of a specific HDL receptor pathway in the duck liver, supporting our hypothesis that CE in Beijing ducks is metabolized directly through the hepatic HDL receptor instead of being transfered back to VLDL and LDL, then through the LDL receptor pathway. This unique way of metabolizing CE may be behind the Beijing duck's antiatherogenicity.展开更多
基金This research was funded by a sub-program of the Ninth Five Years of China: "Study and demonstration of combating technique of sandy disasters in sub-humid-semi-dry zone Yongding River Sandlot"(96-017-01-01).
文摘Based on theories of protective forests and landscape ecology, the reasonableness of structures and patterns of shelterbelt system at Beizang Town, Daxing County, Beijing were analyzed and assessed from the two scales of forest belts and networks, by integrating uses of field investigation, GIS and RS techniques. Results showed that the existent main belt (3-12 m in width) was too narrow, while the assistant belt (3-27.1 m in width) was too wide; the species composition of the existent shelterbelts was single, and the structures and patterns of the shelterbelt system were unreasonable. It is suggested that the structure of the main and the assistant belts should be changed, such as increasing the width of main belts, decreasing the width of assistant belt, and planting more mixed species, and the pattern with arbores in the middle and shrubs in the sides of belts could be taken into account. For the landscape structure of forest network after regenerating or reconstruction, the grid number of closed network should be 13 per km2 and the minimum number of belts should be 34 per km2. This study also testified that integrating GIS and remote technique with landscape ecology could provide an effective method for reasonable reconstruction of the structures and patterns of shelterbelts system.
基金supported by the Major State Basic Research Development Program of China (973 Program) (2009CB421106)Self-deployment & Innovation Project of IGSNRR (200905010)
文摘The water conservation capacities of main forests in Beijing,China were estimated through the quantitative analysis.Various methods developed in published papers on forest hydrology were employed.The forests in Huairou,Yanqing,Miyun,Mentougou and Fangshan districts are the main contributors to water conservation（the cumulative ratio reaches 65%）,and the forests in Tongzhou,Chaoyang,Shunyi and Daxing districts have the highest water conservation capacity（3000 m3/ha）.Altitude and slope are the key factors to affect the water conservation capacity.The forests located in Plain Area,Hilly Area,Low Mountain,and Middle Mountain contributes 27%,28%,24% and 21% of the conserved water,respectively.The water conservation capacity of forests in Plain Area（2 948 m3/ha）,is superior to the forests in other regions.And the forests situated on Flat Slope,Moderate Slope and Gentle Slope constitute the largest proportion（nearly 93%） of water conservation,while the forests on Flat Slope has the highest water conservation capacity（2 797 m3/ha）,and the forest on Steep slope has the lowest water conservation capacity（948 m3/ha）.
基金supported by National Natural Science Foundation of China (31071817)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality(PXM20090142076309)
文摘We investigated characteristics （scales and composition） of soil seed banks at eight study sites in the rocky mountain region of Beijing by seed identification and germination monitoring. We also surveyed the vegetation communities at the eight study sites to explore the role of soil seed banks in vegetation restoration. The storage capacity of soil seed banks at the eight sites ranked from 766.26 to 2461.92 seeds·m？2. A total of 23 plant species were found in soil seed banks, of which 63–80% of seeds were herbs in various soil layers and 60% of seeds were located in the soil layer at 0–5 cm depth. Biodiversity indices indicated clear differences in species diversity of soil seed banks among different plant communities. The species composition of aboveground vegetation showed low similarity with that based on soil seed banks. In the aboveground plant community, the afforestation tree species showed high importance values. The plant species originating from soil seed banks represented natural regeneration, which also showed relatively high importance values. This study suggests that in the rocky mountain region of Beijing the soil seed banks played a key role in the transformation from pure plantation forest to near-natural forest, promoting natural ecological processes, and the role of the seed banks in vegetation restoration was important to the improvement of ecological restoration methods.
基金supported by the Beijing NOVA Program (No. 2005A41)the Mengya Project of the Beijing Academy of Science and Technology (No. MY2008)
文摘A three-year aeropalynological study was carried out in the month of August for each of the three years 2005, 2006 and 2007 in the Beijing Olympic Park. A total of 19550 pollen grains were counted （15057 grains in 2005, 2717 in 2006 and 1776 in 2007） for the following taxa： Gramineae, Chenopodiaceae, Humulus L., Artemisia L., Ambrosia L. and Pinus L. The analysis indicated that in the three consecutive years of 2005-007, airborne pollen types and daily number of pollen in August in the Beijing Olympic Park were closely related to environmental change and vegetation composition. The daily variations of airborne pollen displayed similar patterns in August in each of the three years, which were affected positively by periods of daily sunshine, negatively by daily relative humidity and daily precipitation. Continuously high daily temperatures and stable daily wind speeds seemed to have little effect on the fluctuation of airborne pollen.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11179010 and 11075017 )the Natural Science Foundation of Beijing,China (Grant No. 1102019)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20100003120010)
文摘According to intensity distribution of the synchrotron radiation source focused by a toroidal mirror at the Beijing synchrotron radiation biological macromolecule station, theoretical modeling of the Beijing synchrotron radiation source is developed for capillary optics. Using this theoretical modeling, the influences of the configuration curve of the polycapillary X-ray lens on transmission efficiency and working distance are analyzed. The experimental results of the transmission efficiency and working distance at the biological macromolecule station are in good agreement with the theoretical results.
文摘Objective To understand the perception for the use of cataract surgical services in a population acceptors and non-acceptors of cataract surgery in urban Beijing. Methods From a community-based screening program a total of 158 patients with presenting visual acuity of less than 6/18 on either eye due to age-related cataract were informed about the possibility of surgical treatment. These patients were interviewed and re-examined 36 to 46 months after initial screening. The main reasons for not accepting surgery were obtained using a questionnaire. Vision function and vision-related quality of life scores were assessed in those who received and did not receive surgery. Results At the follow-up examination 116 of the 158 patients were available and 36 （31.0%） had undergone cataract surgery. Cases who chose surgery had higher education level than those who did not seek surgery （OR=2.64, 95% CI： 1.08-6.63, P=0.02）. There were no significant differences in vision function （P=0.11） or quality of life scores （P=0.16） between the surgery group and the non-surgery group. Main reasons for not having surgery included no perceived need （50.0%）, feeling of being ＂too old＂ （19.2%）, and worry about the quality of surgery （9.6%）. Cost was seeking surgery. cited by 1 （1.9%） subject as the main reason for not
文摘The evaluation of ecosystem health has become one of the main research topics of ecosystem science, thus more and more assessment methods and frameworks have been put forward in recent years. However, the attention people pay to ecosystem health is actually more about what the social functions the ecosystem affords, which depend on the integrity and maintenance of the ecosystem structure and function, and the intensity of disturbance from outside. Accordingly, this research commenced from three main aspects, selected the evaluation indices, and then established the Evaluation Index System of Beijing Forest Ecosystem Health （EIS-BFEH）. In the EIS-BFEH, each of the three foundations contained an easily-operated and standard sub-index system, which compounded the specific natural and social conditions of Beijing and was concrete enough to measure and evaluate. Then with the method of the Analytical Hierarchy Process （AHP）, the comprehensive index （CI） could be obtained, which represented the health of the forest ecosystem. As a case study, the forest ecosystems in the Badaling area were sampled, evaluated, compared and ranked by use of the EIS-BFEH. The result show that the health of natural forests is much better than that of plantations in the Badaling forest center： the average comprehensive index of the former is 7.9, while the latter is only 6.6. From the results, it could also be found that there are nine units in the healthy state, two units in the subhealthy state, and only one unit of Robiniapseudoacacia in the morbid state.
文摘The 1st International Conference on Data-driven Knowledge Discovery： When Data Science Meets Information Science took place at the National Science Library （NSL）, Chinese Academy of Sciences （CAS） in Beijing from June 19 till June 22, 2016. The Conference was opened by NSL Director Xiangyang Huang, who placed the event within the goals of the Library, and lauded the spirit of intemational collaboration in the area of data science and knowledge discovery. The whole event was an encouraging success with over 370 registered participants and highly enlightening presentations. The Conference was organized by the Journal of Data andlnformation Science （JDIS） to bring the Joumal to the attention of an international and local audience.
基金Project supported by the Chinese Academy of Science Innovation Key Project (Grant No KJCX2-SW-N06)
文摘This paper reports that at a newly constructed small-angle x-ray scattering station of Beijing Synchrotron Radia- tion Facility, the topological shape of ligand-free bovine serum albumin in solution has been investigated. An appropriate scattering curve is obtained and the calculated value of the gyration radius is 31.2~=t=0.25 ~_ （11=0.1 nm） which is co- incident with other ones＇ results. It finds that the low-resolution structure models obtained by making use of ab initio reconstruction methods are fitting the crystal structure of human serum albumin very well. All of these results perform the potential of the beamline to apply to structural biology studies. The characteristics, the defects, and the improving measures of the station in future are also discussed.
基金Project supported by the National Natural Science Foundation of China （Grant No 10174079）, the Natural Science Foundation of Zhejiang Province, China （Grant No Y104203） and BEPC National Laboratory （Grant No sr-03062）.
文摘The x-ray compound lens is a novel refractive x-ray optical device. This paper reports the authors＇ recent research on a polymethyl methacrylate （PMMA） compound x-ray lens. Firstly the designing and LIGA fabrication process for the PMMA compound x-ray lens are briefly described. Then, a method for theoretical analysis, as well as the experimental system for measurement is also introduced. Finally, the focusing spots for 8keV monochromatic x-rays by the PMMA compound x-ray lens are measured and analysed. According to the experimental results, it is concluded that the PMMA compound x-ray lens promises a good focusing performance under the high-energy x-rays.
文摘Hao Jingfang's science-fiction novelette Folding Beijing was named the Best Novelette at the Hugos on August 21st, 2016. It is originally written in Chinese and gain recognition among foreign readers after being translated into English. The fact that the translation put Chinese science-fiction on the international map again after the Hugo-award winning science-fiction The Three Body Problem written by Liu Cixin is an important event in Chinese science-fiction translation history. The contribution of Ken Liu's English version should not be neglected. This paper looks at the successful translation and its communication from the perspective of Multiple Causality of Translation proposed by Anthony Pym to probe into the kind of causation operative in the translation of Folding Beijing, including the material or initial cause, the final cause, the formal cause, and the efficient cause. Ken Liu's English version has made such a great success that a study of its formation and development may provide insights for home translators longing to help Chinese science-fiction reach more readers.
文摘It had been found that Beijing ducks(BD) have a high level of HDL(70%), high LCAT but very low CETP activity and will not develop atherosclerosis on an atherogenic diet, suggesting that cholesterol ester is mainly carried by HDL and metabolized through an HDL receptor pathway in the liver. However, evidence of this receptor′s existence in the liver is not yet complete. In this paper. the HDL receptor in BD liver has been studied. Our experiments showed : 1 ) ApoE-free 125 I-HDL could bind specifically to duck hepatic cell membrane with high affinity (Kd=9.6μg/ml) and was saturable (Bmax=8.9μg/mg cell membrane protein)at room temperature 2)Competitive inhibition studies with unlabelled duck, human, rat and chick HDL and duck apo AI and its liposomes formed with PC or DMPC could inhibit the binding of 125I-HDL to duck hepatic cell membranes, but LDL,apo E and their liposomes with PC or DMPC could not with the exception of duck LDL. 3) The receptor could recognize apo AI but not apo B or E. 4 ) Both phosphorase A2 and pronase could inhibit the binding activity. The above results give strong evidence for the existence of a specific HDL receptor pathway in the duck liver, supporting our hypothesis that CE in Beijing ducks is metabolized directly through the hepatic HDL receptor instead of being transfered back to VLDL and LDL, then through the LDL receptor pathway. This unique way of metabolizing CE may be behind the Beijing duck's antiatherogenicity.
