Phosphorus index method is an effective method to assess the risk of phosphorus loss,identify the critical source areas and reasonably control the agricultural non-point source pollution.The researches on phosphorus i...Phosphorus index method is an effective method to assess the risk of phosphorus loss,identify the critical source areas and reasonably control the agricultural non-point source pollution.The researches on phosphorus index assessment method have been started earlier in foreign countries.Currently,phosphorus index assessment method has been widely used in the United States and European countries through continuous development and improvement.However,the domestic research on non-point source phosphorus pollution assessment has just started,and the phosphorus index method that is suitable for the characteristics of agriculture in China has not yet been established.This paper summarizes and analyzes systematically the related research advances in phosphorus index method at home and abroad,and illustrates the issues presented in phosphorus index method.In addition,the researches on and application of phosphorus index method in China are discussed.展开更多
Traditionally governance structures are classified into ＂hierarchy or market＂ or ＂equity or non-equity.＂ However,such classifications may not be effective in characterizing all governance structures of research an...Traditionally governance structures are classified into ＂hierarchy or market＂ or ＂equity or non-equity.＂ However,such classifications may not be effective in characterizing all governance structures of research and development（R D） alliances.Therefore,the first objective of this study is to investigate why there exist different organizational governance structures in managing R D alliances;the second objective of this study is to give strategic advice in choosing appropriate forms with respect to various characteristics of R D alliances.Through the theoretical lens that integrate both transaction cost economics（TCE） and the resource-based view（RBV）,a model that focuses on six major factors is developed for determining governance structure choices,namely,technological uncertainty,cultural difference,asset specificity,technology complementarity,appropriability of the individual firm＇s know-how,and trust.An R D alliance with higher technological uncertainty,larger cultural differences,and greater concerns for protecting an individual＇s know-how is more likely to adopt non-integrated alliances as the governing structure.An R D alliance with a higher degree of asset-specificity,greater technology complementarity and greater trust among partnering organizations is more likely to adopt integrated alliances as the governing structure;an R D alliance in the face of lower technological uncertainty will tend to adopt integrated alliances.The more aligned the choice of the governance structure with its determinants,the better the R D alliance will perform,and vice versa.展开更多
A simultaneous experimental and numerical study on crack propagation in the pre-cracked beams specimens(concrete-like materials) is carried out using three-point bending flexural test. The crack propagation and coales...A simultaneous experimental and numerical study on crack propagation in the pre-cracked beams specimens(concrete-like materials) is carried out using three-point bending flexural test. The crack propagation and coalescence paths of internal cracks in side beam specimens are experimentally studied by inserting double internal cracks. The effects of crack positions on the fracturing path in the bridge areas of the double cracked beam specimens are also studied. It has been observed that the breaking of concrete-like cracked beams specimens occurs mainly by the propagation of wing cracks emanating from the tips of the pre-existing cracks in the numerical and experimental analyses, respectively. The same specimens are numerically simulated by an indirect boundary element method(IBEM) known as displacement discontinuity method(DDM) using higher displacement discontinuity. These numerical results are compared with the existing experimental results. This comparison illustrates the higher accuracy of the results obtained by the indirect boundary element method by using only a small number of elements compared with the discrete element method(PFC2D code).展开更多
It proves to be a tough job to define culture and to draw characteristics of culture or work out the categories of culture. Based on some influential definitions, and achievements made in sociology and anthropology, t...It proves to be a tough job to define culture and to draw characteristics of culture or work out the categories of culture. Based on some influential definitions, and achievements made in sociology and anthropology, this paper makes an attempt to summarize and discuss some characteristics of culture. With regard to the categorization of culture, we put forward the idea that it is closely related to the definition and features of culture, and also that it is closely related with human cognition and different perspectives, and thus culture category is an open system just as culture in general. Cultural development as product of human evolution and development is both a need and reality, going on through cultural transmission. In the process, it is human nature to encounter cultural conflicts like culture shock, the solution of which partially depends on cultural studies, on a close relationship with the main school of culture or dominating culture and on seeking similarities and accepting differences, and in a word, on friendly and cordial contacts and understanding through linguistic communication.展开更多
Based on the WoS and CNKI databases,this paper provides statistical analysis of Chinese and international polar research from 2013-2018 in terms of the number of publications,citations,institutions,disciplinary distri...Based on the WoS and CNKI databases,this paper provides statistical analysis of Chinese and international polar research from 2013-2018 in terms of the number of publications,citations,institutions,disciplinary distribution,collaborations,source journals,and highly cited papers by bibliometric methods.Combining the differences of the traditional disciplinary advantages and natural geographical locations of China and the West,the current research hotspots in the polar field are summarized.(1)"Polar ice cap instability and sea level change","sensitivity and vulnerability of polar ecosystems","Arctic sea-ice-air interactions and climate effects"are the focus of research in the world.(2)Political environment research such as"National Strategy and Cooperation under the'Silk Road on Ice'Initiative"has become a unique polar strategic topic in China.At the same time,insights and suggestions are put forward from three aspects,such as increasing policy support,building cooperation system and optimizing strategic layout.展开更多
Objective： To analyze hot research areas and the present research status of nursing safety management in PubMed. Methods： PubMed was searched using ＂safety management＂ for the literature on nursing safety manageme...Objective： To analyze hot research areas and the present research status of nursing safety management in PubMed. Methods： PubMed was searched using ＂safety management＂ for the literature on nursing safety management. BICOMB 2.0 and SPSS 20.0 software were used to analyze high-frequency keywords and conduct co-word clustering analysis. Results： We searched for totally 2353 articles related to our topic and extracted 19 high-frequency keywords （27.50%）. Five research focuses were concluded, including： study on nursing safety culture; team work to promote nursing safety; practice of nursing safety management; workplace violence against nursing staffs; nursing safety and quality evaluation standard. Conclusion： Analysis of the hotspots of nursing safety management in the past 10 years will contribute to understanding the research emphases and trend of development, and provide reference for the study and practice of nursing safety management.展开更多
With isopentane as working fluid, the heat transfer performances for corrugated, nodal and horizontal grain tubes are simulated. The structural parameters of the three kinds of tubes are compared with those of the pla...With isopentane as working fluid, the heat transfer performances for corrugated, nodal and horizontal grain tubes are simulated. The structural parameters of the three kinds of tubes are compared with those of the plain tube. The numerical results using computational fluid dynamics are validated with theoretical values. For the corrugated, nodal and horizontal grain tubes, the heat transfer enhancements(HTEs) are 2.31—2.53, 1.18—1.86 and 1.02—1.31 times of those of the plain tube, respectively. However, the improved HTEs are at the expense of pressure losses. The drag coefficients are 6.10—7.09, 2.06—11.03 and 0.53—1.83 higher, respectively. From the viewpoint of comprehensive heat transfer factor, the corrugated tube is recommended for engineering applications, followed by the horizontal grain tube.展开更多
AIM： To examine the clinical characteristics of a subgroup of patients with hepatocellular carcinoma （HCC） and compare them to those with known risk factors. METHODS： We used the HCC database of 306 patients seen ...AIM： To examine the clinical characteristics of a subgroup of patients with hepatocellular carcinoma （HCC） and compare them to those with known risk factors. METHODS： We used the HCC database of 306 patients seen at our institution from January 1, 1995 to December 31, 2001. Of the 306 patients, 63 （20%, group 1） had no known risk factors （hepatitis C virus, hepatitis B virus, alcohol, hemochromatosis or cirrhosis from any cause） and 243 （group 2） had one or more risk factors. RESULTS： The median age was similar in both groups, but there were disproportionate numbers of younger （〈 30 years old）, older （〉 80 years） patients, women （33% vs 18%）, and Caucasians （81% vs 52%） in group 1 as compared to group 2. There were fewer Asians （2% vs 11%） and African Americans （13% vs 27%） in group 1. Abdominal pain （70% vs 37%） was more common while gastrointestinal bleeding （0% vs 11%） and ascites （4% vs17%） were less common in group i compared to group 2. Group 1 had larger tumor burden （median size 9.4 cm vs 5.7 cm） at the time of presentation, but there were no differences in the site （right, left or bilateral lesions）, or number of tumors between the two groups. CONCLUSION： HCC patients without identifiable risk factors have different characteristics and clinical presentation compared to those with known risk factors.Absence of cirrhosis and larger tumor burden may explain the differences in the presenting symptoms.展开更多
基金Supported by National Key Technology Research and Development Program(2012BAD15B03)Special Fund for Agro-scientific Research in the Public Interest(201003014)~~
文摘Phosphorus index method is an effective method to assess the risk of phosphorus loss,identify the critical source areas and reasonably control the agricultural non-point source pollution.The researches on phosphorus index assessment method have been started earlier in foreign countries.Currently,phosphorus index assessment method has been widely used in the United States and European countries through continuous development and improvement.However,the domestic research on non-point source phosphorus pollution assessment has just started,and the phosphorus index method that is suitable for the characteristics of agriculture in China has not yet been established.This paper summarizes and analyzes systematically the related research advances in phosphorus index method at home and abroad,and illustrates the issues presented in phosphorus index method.In addition,the researches on and application of phosphorus index method in China are discussed.
基金The Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Traditionally governance structures are classified into ＂hierarchy or market＂ or ＂equity or non-equity.＂ However,such classifications may not be effective in characterizing all governance structures of research and development（R D） alliances.Therefore,the first objective of this study is to investigate why there exist different organizational governance structures in managing R D alliances;the second objective of this study is to give strategic advice in choosing appropriate forms with respect to various characteristics of R D alliances.Through the theoretical lens that integrate both transaction cost economics（TCE） and the resource-based view（RBV）,a model that focuses on six major factors is developed for determining governance structure choices,namely,technological uncertainty,cultural difference,asset specificity,technology complementarity,appropriability of the individual firm＇s know-how,and trust.An R D alliance with higher technological uncertainty,larger cultural differences,and greater concerns for protecting an individual＇s know-how is more likely to adopt non-integrated alliances as the governing structure.An R D alliance with a higher degree of asset-specificity,greater technology complementarity and greater trust among partnering organizations is more likely to adopt integrated alliances as the governing structure;an R D alliance in the face of lower technological uncertainty will tend to adopt integrated alliances.The more aligned the choice of the governance structure with its determinants,the better the R D alliance will perform,and vice versa.
文摘A simultaneous experimental and numerical study on crack propagation in the pre-cracked beams specimens(concrete-like materials) is carried out using three-point bending flexural test. The crack propagation and coalescence paths of internal cracks in side beam specimens are experimentally studied by inserting double internal cracks. The effects of crack positions on the fracturing path in the bridge areas of the double cracked beam specimens are also studied. It has been observed that the breaking of concrete-like cracked beams specimens occurs mainly by the propagation of wing cracks emanating from the tips of the pre-existing cracks in the numerical and experimental analyses, respectively. The same specimens are numerically simulated by an indirect boundary element method(IBEM) known as displacement discontinuity method(DDM) using higher displacement discontinuity. These numerical results are compared with the existing experimental results. This comparison illustrates the higher accuracy of the results obtained by the indirect boundary element method by using only a small number of elements compared with the discrete element method(PFC2D code).
文摘It proves to be a tough job to define culture and to draw characteristics of culture or work out the categories of culture. Based on some influential definitions, and achievements made in sociology and anthropology, this paper makes an attempt to summarize and discuss some characteristics of culture. With regard to the categorization of culture, we put forward the idea that it is closely related to the definition and features of culture, and also that it is closely related with human cognition and different perspectives, and thus culture category is an open system just as culture in general. Cultural development as product of human evolution and development is both a need and reality, going on through cultural transmission. In the process, it is human nature to encounter cultural conflicts like culture shock, the solution of which partially depends on cultural studies, on a close relationship with the main school of culture or dominating culture and on seeking similarities and accepting differences, and in a word, on friendly and cordial contacts and understanding through linguistic communication.
文摘Based on the WoS and CNKI databases,this paper provides statistical analysis of Chinese and international polar research from 2013-2018 in terms of the number of publications,citations,institutions,disciplinary distribution,collaborations,source journals,and highly cited papers by bibliometric methods.Combining the differences of the traditional disciplinary advantages and natural geographical locations of China and the West,the current research hotspots in the polar field are summarized.(1)"Polar ice cap instability and sea level change","sensitivity and vulnerability of polar ecosystems","Arctic sea-ice-air interactions and climate effects"are the focus of research in the world.(2)Political environment research such as"National Strategy and Cooperation under the'Silk Road on Ice'Initiative"has become a unique polar strategic topic in China.At the same time,insights and suggestions are put forward from three aspects,such as increasing policy support,building cooperation system and optimizing strategic layout.
文摘Objective： To analyze hot research areas and the present research status of nursing safety management in PubMed. Methods： PubMed was searched using ＂safety management＂ for the literature on nursing safety management. BICOMB 2.0 and SPSS 20.0 software were used to analyze high-frequency keywords and conduct co-word clustering analysis. Results： We searched for totally 2353 articles related to our topic and extracted 19 high-frequency keywords （27.50%）. Five research focuses were concluded, including： study on nursing safety culture; team work to promote nursing safety; practice of nursing safety management; workplace violence against nursing staffs; nursing safety and quality evaluation standard. Conclusion： Analysis of the hotspots of nursing safety management in the past 10 years will contribute to understanding the research emphases and trend of development, and provide reference for the study and practice of nursing safety management.
基金Supported by the National High Technology Research and Development Program of China("863"Program,No.2012AA053001)
文摘With isopentane as working fluid, the heat transfer performances for corrugated, nodal and horizontal grain tubes are simulated. The structural parameters of the three kinds of tubes are compared with those of the plain tube. The numerical results using computational fluid dynamics are validated with theoretical values. For the corrugated, nodal and horizontal grain tubes, the heat transfer enhancements(HTEs) are 2.31—2.53, 1.18—1.86 and 1.02—1.31 times of those of the plain tube, respectively. However, the improved HTEs are at the expense of pressure losses. The drag coefficients are 6.10—7.09, 2.06—11.03 and 0.53—1.83 higher, respectively. From the viewpoint of comprehensive heat transfer factor, the corrugated tube is recommended for engineering applications, followed by the horizontal grain tube.
文摘AIM： To examine the clinical characteristics of a subgroup of patients with hepatocellular carcinoma （HCC） and compare them to those with known risk factors. METHODS： We used the HCC database of 306 patients seen at our institution from January 1, 1995 to December 31, 2001. Of the 306 patients, 63 （20%, group 1） had no known risk factors （hepatitis C virus, hepatitis B virus, alcohol, hemochromatosis or cirrhosis from any cause） and 243 （group 2） had one or more risk factors. RESULTS： The median age was similar in both groups, but there were disproportionate numbers of younger （〈 30 years old）, older （〉 80 years） patients, women （33% vs 18%）, and Caucasians （81% vs 52%） in group 1 as compared to group 2. There were fewer Asians （2% vs 11%） and African Americans （13% vs 27%） in group 1. Abdominal pain （70% vs 37%） was more common while gastrointestinal bleeding （0% vs 11%） and ascites （4% vs17%） were less common in group i compared to group 2. Group 1 had larger tumor burden （median size 9.4 cm vs 5.7 cm） at the time of presentation, but there were no differences in the site （right, left or bilateral lesions）, or number of tumors between the two groups. CONCLUSION： HCC patients without identifiable risk factors have different characteristics and clinical presentation compared to those with known risk factors.Absence of cirrhosis and larger tumor burden may explain the differences in the presenting symptoms.
