[Objective] The study aimed to analyze vegetation succession process under groundwater mining conditions in Subei Lake watershed. [ Method] A succession model for vegetation and burial depth of groundwater level was c...[Objective] The study aimed to analyze vegetation succession process under groundwater mining conditions in Subei Lake watershed. [ Method] A succession model for vegetation and burial depth of groundwater level was constructed based on field survey, and it was used to pre- dict the vegetation succession rules and process according to the changes in burial depth of groundwater level in Subei Lake watershed under groundwater exploitation. [ Result~ In Subei Lake watershed, aquatic vegetation was most closely related to burial depth of groundwater level, fol- lowed by mesophytic vegetation, while psammophilous and xerophytic vegetation did not have obvious relation with burial depth of groundwater lev- el. When burial depth of groundwater level was small, dominant plants grew well, but they grew worse or died with the increase in burial depth of groundwater level. As the groundwater level fell constantly, burial depth of groundwater level went up, and vegetation succession would occur grad- ually from aquatic vegetation to mesophytic and xerophytic vegetation, from Carex L. and Iris ensata Thunb shoaly land to Achnatherum splendens shoaly lands, from Salix psammophila shrubs to Artemisia desterorum Spreng and Caragana korshinskii shrubs, and from Populus simonii to Salix matsudana. [Condusion] The research could provide scientific references for studying the relationship between groundwater resources and ecological environment in Subei Lake basin.展开更多
Background： Tropical forests play an important role in the global carbon（C） cycle.However, tropical montane forests have been studied less than tropical lowland forests, and their role in carbon storage is not well...Background： Tropical forests play an important role in the global carbon（C） cycle.However, tropical montane forests have been studied less than tropical lowland forests, and their role in carbon storage is not well understood.Montane forests are highly endangered due to logging, land-use and climate change.Our objective was to analyse how the carbon balance changes during forest succession.Methods： In this study, we used a method to estimate local carbon balances that combined forest inventory data with process-based forest models.We utilised such a forest model to study the carbon balance of a tropical montane forest in South Ecuador, comparing two topographical slope positions（ravines and lower slopes vs upper slopes and ridges）.Results： The simulation results showed that the forest acts as a carbon sink with a maximum net ecosystem exchange（NEE） of 9.3 Mg C？（ha？yr）-1during its early successional stage（0–100 years）.In the late successional stage, the simulated NEE fluctuated around zero and had a variation of 0.77 Mg C？（ha？yr）–1.The simulated variability of the NEE was within the range of the field data.We discovered several forest attributes（e.g., basal area or the relative amount of pioneer trees） that can serve as predictors for NEE for young forest stands（0–100 years） but not for those in the late successional stage（500–1,000 years）.In case of young forest stands these correlations are high, especially between stand basal area and NEE.Conclusion： In this study, we used an Ecuadorian study site as an example of how to successfully link a forest model with forest inventory data, for estimating stem-diameter distributions, biomass and aboveground net primary productivity.To conclude, this study shows that process-based forest models can be used to investigate the carbon balance of tropical montane forests.With this model it is possible to find hidden relationships between forest attributes and forest carbon fluxes.These relationships promote a better understanding of the role of tropical montane forests in the context of global carbon cycle, which in future will become more relevant to a society under global change.展开更多
Global climate change is having long-term impacts on the geographic distribution of forest species. However, the response of vertical belts of mountain forests to climate change is still little known. The vertical dis...Global climate change is having long-term impacts on the geographic distribution of forest species. However, the response of vertical belts of mountain forests to climate change is still little known. The vertical distribution of forest vegetation(vertical vegetation belt) on Gongga Mountain in Southwest China has been monitored for 30 years. The forest alternation of the vertical vegetation belt under different climate conditions was simulated by using a mathematical model GFSM(the Gongga Forest Succession Model). Three possible Intergovernmental Panel on Climate Change(IPCC) climate scenarios(increase of air temperature and precipitation by 1.8℃/5%, 2.8℃/10% and 3.4℃/15% for B_1, A_1B and A_2 scenarios, respectively) were chosen to reflect lower, medium and higher changes of global climate. The vertical belts of mountainous vegetation will shift upward by approximately 300 m, 500 m and 600 m in the B_1, A_1B and A_2 scenarios, respectively, according to the simulated results. Thus, the alpine tree-line will move to a higher altitude. The simulation also demonstrated that, in a changing climate, the shift in the vegetation community will be a slow and extended process characterized by two main phases. During the initial phase, trees of the forest community degrade or die, owing to an inability to adapt to a warmer climate. This results in modest environment for the introduction of opportunistic species, consequently, the vegetation with new dominant tree species becomes predominant in the space vacated by the dead trees at the expense of previously dominated original trees as the succession succeed and climate change advance. Hence, the global climate change would dramatically change forest communities and tree species in mountainous regions because that the new forest community can grow only through the death of the original tree. Results indicated that climate change will cause the change of distribution and composition of forest communities on Gongga Mountain, and this change may enhance as the intensity of climate change increases. As a result, the alternation of death and rebirth would finally result in intensive landscape changes, and may strongly affect the eco-environment of mountainous regions.展开更多
Using the characteristic of addition of information quantity and the principle of equivalence of information quantity, this paper derives the general conversion formulae of the formation theory method conversion (synt...Using the characteristic of addition of information quantity and the principle of equivalence of information quantity, this paper derives the general conversion formulae of the formation theory method conversion (synthesis) on the systems consisting of different success failure model units. According to the fundamental method of the unit reliability assessment, the general models of system reliability approximate lower limits are given. Finally, this paper analyses the application of the assessment method by examples, the assessment results are neither conservative nor radical and very satisfactory. The assessment method can be popularized to the systems which have fixed reliability structural models.展开更多
In recent years,the telecommunications sector is no longer limited to traditional communications,but has become the backbone for the use of data,content and digital applications by individuals,governments and companie...In recent years,the telecommunications sector is no longer limited to traditional communications,but has become the backbone for the use of data,content and digital applications by individuals,governments and companies to ensure the continuation of economic and social activity in light of social distancing and total closure inmost countries in the world.Therefore,electronic government(e-Government)andmobile government(m-Government)are the results of technological evolution and innovation.Hence,it is important to investigate the factors that influence the intention to use m-Government services among Jordan’s society.This paper proposed a new m-Government acceptance model in Jordan(AMGS);this model combines the Information System(IS)Success Factor Model and Hofstede Cultural Dimensions Theory.The study was conducted by surveying different groups of the Jordanian community.Astructured questionnaire was used to collect data from203 respondents.Multiple regression analysis has been conducted to analyze the data.The results indicate that the significant predictors of citizen intention to use m-Government services in Jordan are Information Quality,Service Quality,Uncertainty Avoidance,and Indulgence vs.restraint.While,the results also suggest that Power Distance is not a significant predictor of citizen intention to use m-Government services.展开更多
On July 4th,2016,China COSCO Shipping Corporation Limited('COSCO SHIPPING'or'the Group')and the Hellenic Republic Asset Development Fund(HRADF)signed a letter in Beijing,confirming that the conditions ...On July 4th,2016,China COSCO Shipping Corporation Limited('COSCO SHIPPING'or'the Group')and the Hellenic Republic Asset Development Fund(HRADF)signed a letter in Beijing,confirming that the conditions defined in the previously signed Share Purchase Agreement(SPA)have been fulfilled.It marks a decisive achievement for COSCO SHIPPING’S展开更多
Purpose： This study intends to examine the factors that influence Chinese college students＇ use of the lnternet for acquiring information. Design/methodology/approach： This paper developed the research model by usi...Purpose： This study intends to examine the factors that influence Chinese college students＇ use of the lnternet for acquiring information. Design/methodology/approach： This paper developed the research model by using the technology acceptance model （TAM） and information system success model as the theoretical foundation. The proposed model was empirically tested with the structural equation modeling technique based on data collected from a survey of 357 college students. Findings： The results show that 1） perceived ease of use, perceived usefulness and perceived playfulness all have a positive impact on the intention to use the Internet for acquiring information, 2） use context and system quality significantly influence perceived usefulness and perceived ease of use, and 3） service quality has a positive impact on perceived ease of use but not on perceived usefulness. Likewise information quality has no positive effect on perceived usefulness. Research limitations： The survey respondents were mainly from college students in Nanjing. We need to recruit college students in the western or other developing areas in China to further validate our findings. Practical implications： This study puts forward some feasible suggestions for university libraries to improve information organization and the use of digital library resources to better meet the needs of library users. Originality/value： This study provides insights into the understanding of the factors affecting college students＇ online information acquisition from multiple perspectives.展开更多
Knowledge Management(KM)has become a dynamic concept for inquiry in research.The management of knowledge from multiple sources requires a systematic approach that can facilitate capturing all important aspects related...Knowledge Management(KM)has become a dynamic concept for inquiry in research.The management of knowledge from multiple sources requires a systematic approach that can facilitate capturing all important aspects related to a particular discipline,several KM frameworks have been designed to serve this purpose.This research aims to propose a Collaborative Knowledge Management(CKM)Framework that bridges gaps and overcomes weaknesses in existing frameworks.The paper also validates the framework by evaluating its effectiveness for the agriculture sector of Pakistan.A software LCWU aKMS was developed which serves as a practical implementation of the concepts behind the proposed CKMF framework.LCWU aKMS served as an effective system for rice leaf disease detection and identification.It aimed to enhance CKM through knowledge sharing,lessons learned,feedback on problem resolutions,help from co-workers,collaboration,and helping communities.Data were collected from 300 rice crop farmers by questionnaires based on hypotheses.Jennex Olfman model was used to estimate the effectiveness of CKMF.Various tests were performed including frequency measures of variables,Cronbach’s alpha reliability,and Pearson’s correlation.The research provided a KMS depicting KM and collaborative features.The disease detection module was evaluated using the precision and recall method and found to be 94.16%accurate.The system could replace the work of extension agents,making it a cost and time-effective initiative for farmer betterment.展开更多
Purpose： The aim of this paper is to measure the success of HISs （hospital information systems） in Bahrain from their end user’s perspectives. Methodology： a quantitative design using a questionnaire based on...Purpose： The aim of this paper is to measure the success of HISs （hospital information systems） in Bahrain from their end user’s perspectives. Methodology： a quantitative design using a questionnaire based on the DeLone and McLean Information System Success Model （2003） was employed to examine the key determinants comprise of SQ （system quality）, IQ （information quality）, SerQ （service quality） as the independent variables and their effect on the US （user satisfaction）, U （system use） and the perceived NB （net benefits） as the success measures. There are 324 respondents consisting of doctors, nurses, technicians, pharmacists and admin staff of hospitals. Data were analyzed using SPSS. Findings： SQ, IQ and SerQ are significantly positively related to US and U, and the two later are in turns significantly positively related to the perceived NB out of the system to both users and organizations. Research implications： the research reflects the experience of using innovative healthcare technologies in the Middle East and its results show the importance of improving the systems technical quality to ensure more satisfied users, more utilized technologies and to reach the optimal purpose of implementing these systems and reap out their prospected benefits. Moreover, sufficient training and full dependency on the systems are required to get more confident users and reduce the daily work load.展开更多
We analyse further the reliability behaviour of series and parallel systems in the successive damage model initiated by Downton. The results are compared with those obtained for other models with different bivariate d...We analyse further the reliability behaviour of series and parallel systems in the successive damage model initiated by Downton. The results are compared with those obtained for other models with different bivariate distributions.展开更多
A special economic zone’s three-decade economic miracle is celebrated shenzhen, a southern coastal cityin Guangdong Province, neighboring Hong Kong, has markedits 30th anniversary as China’s first economic developme...A special economic zone’s three-decade economic miracle is celebrated shenzhen, a southern coastal cityin Guangdong Province, neighboring Hong Kong, has markedits 30th anniversary as China’s first economic development zone.展开更多
基金Supported by the Large Survey Project of Ministry of Land and Resources,China (1212010734002)
文摘[Objective] The study aimed to analyze vegetation succession process under groundwater mining conditions in Subei Lake watershed. [ Method] A succession model for vegetation and burial depth of groundwater level was constructed based on field survey, and it was used to pre- dict the vegetation succession rules and process according to the changes in burial depth of groundwater level in Subei Lake watershed under groundwater exploitation. [ Result~ In Subei Lake watershed, aquatic vegetation was most closely related to burial depth of groundwater level, fol- lowed by mesophytic vegetation, while psammophilous and xerophytic vegetation did not have obvious relation with burial depth of groundwater lev- el. When burial depth of groundwater level was small, dominant plants grew well, but they grew worse or died with the increase in burial depth of groundwater level. As the groundwater level fell constantly, burial depth of groundwater level went up, and vegetation succession would occur grad- ually from aquatic vegetation to mesophytic and xerophytic vegetation, from Carex L. and Iris ensata Thunb shoaly land to Achnatherum splendens shoaly lands, from Salix psammophila shrubs to Artemisia desterorum Spreng and Caragana korshinskii shrubs, and from Populus simonii to Salix matsudana. [Condusion] The research could provide scientific references for studying the relationship between groundwater resources and ecological environment in Subei Lake basin.
基金financial support of the German Research Foundation(DFG,Research Unit 816)for initializing the forest plots and the plot census as well as a first model parameterisationthe Helmholtz Alliance:Remote Sensing and Earth System Dynamics for financing the work on the further parameterisation of the model and analysis of the data
文摘Background： Tropical forests play an important role in the global carbon（C） cycle.However, tropical montane forests have been studied less than tropical lowland forests, and their role in carbon storage is not well understood.Montane forests are highly endangered due to logging, land-use and climate change.Our objective was to analyse how the carbon balance changes during forest succession.Methods： In this study, we used a method to estimate local carbon balances that combined forest inventory data with process-based forest models.We utilised such a forest model to study the carbon balance of a tropical montane forest in South Ecuador, comparing two topographical slope positions（ravines and lower slopes vs upper slopes and ridges）.Results： The simulation results showed that the forest acts as a carbon sink with a maximum net ecosystem exchange（NEE） of 9.3 Mg C？（ha？yr）-1during its early successional stage（0–100 years）.In the late successional stage, the simulated NEE fluctuated around zero and had a variation of 0.77 Mg C？（ha？yr）–1.The simulated variability of the NEE was within the range of the field data.We discovered several forest attributes（e.g., basal area or the relative amount of pioneer trees） that can serve as predictors for NEE for young forest stands（0–100 years） but not for those in the late successional stage（500–1,000 years）.In case of young forest stands these correlations are high, especially between stand basal area and NEE.Conclusion： In this study, we used an Ecuadorian study site as an example of how to successfully link a forest model with forest inventory data, for estimating stem-diameter distributions, biomass and aboveground net primary productivity.To conclude, this study shows that process-based forest models can be used to investigate the carbon balance of tropical montane forests.With this model it is possible to find hidden relationships between forest attributes and forest carbon fluxes.These relationships promote a better understanding of the role of tropical montane forests in the context of global carbon cycle, which in future will become more relevant to a society under global change.
基金funded by the National Natural Science Foundation of China (Grant Nos. 41671016 and 41671262)
文摘Global climate change is having long-term impacts on the geographic distribution of forest species. However, the response of vertical belts of mountain forests to climate change is still little known. The vertical distribution of forest vegetation(vertical vegetation belt) on Gongga Mountain in Southwest China has been monitored for 30 years. The forest alternation of the vertical vegetation belt under different climate conditions was simulated by using a mathematical model GFSM(the Gongga Forest Succession Model). Three possible Intergovernmental Panel on Climate Change(IPCC) climate scenarios(increase of air temperature and precipitation by 1.8℃/5%, 2.8℃/10% and 3.4℃/15% for B_1, A_1B and A_2 scenarios, respectively) were chosen to reflect lower, medium and higher changes of global climate. The vertical belts of mountainous vegetation will shift upward by approximately 300 m, 500 m and 600 m in the B_1, A_1B and A_2 scenarios, respectively, according to the simulated results. Thus, the alpine tree-line will move to a higher altitude. The simulation also demonstrated that, in a changing climate, the shift in the vegetation community will be a slow and extended process characterized by two main phases. During the initial phase, trees of the forest community degrade or die, owing to an inability to adapt to a warmer climate. This results in modest environment for the introduction of opportunistic species, consequently, the vegetation with new dominant tree species becomes predominant in the space vacated by the dead trees at the expense of previously dominated original trees as the succession succeed and climate change advance. Hence, the global climate change would dramatically change forest communities and tree species in mountainous regions because that the new forest community can grow only through the death of the original tree. Results indicated that climate change will cause the change of distribution and composition of forest communities on Gongga Mountain, and this change may enhance as the intensity of climate change increases. As a result, the alternation of death and rebirth would finally result in intensive landscape changes, and may strongly affect the eco-environment of mountainous regions.
文摘Using the characteristic of addition of information quantity and the principle of equivalence of information quantity, this paper derives the general conversion formulae of the formation theory method conversion (synthesis) on the systems consisting of different success failure model units. According to the fundamental method of the unit reliability assessment, the general models of system reliability approximate lower limits are given. Finally, this paper analyses the application of the assessment method by examples, the assessment results are neither conservative nor radical and very satisfactory. The assessment method can be popularized to the systems which have fixed reliability structural models.
基金This research funded by Al-Zaytoonah University of Jordan.
文摘In recent years,the telecommunications sector is no longer limited to traditional communications,but has become the backbone for the use of data,content and digital applications by individuals,governments and companies to ensure the continuation of economic and social activity in light of social distancing and total closure inmost countries in the world.Therefore,electronic government(e-Government)andmobile government(m-Government)are the results of technological evolution and innovation.Hence,it is important to investigate the factors that influence the intention to use m-Government services among Jordan’s society.This paper proposed a new m-Government acceptance model in Jordan(AMGS);this model combines the Information System(IS)Success Factor Model and Hofstede Cultural Dimensions Theory.The study was conducted by surveying different groups of the Jordanian community.Astructured questionnaire was used to collect data from203 respondents.Multiple regression analysis has been conducted to analyze the data.The results indicate that the significant predictors of citizen intention to use m-Government services in Jordan are Information Quality,Service Quality,Uncertainty Avoidance,and Indulgence vs.restraint.While,the results also suggest that Power Distance is not a significant predictor of citizen intention to use m-Government services.
文摘On July 4th,2016,China COSCO Shipping Corporation Limited('COSCO SHIPPING'or'the Group')and the Hellenic Republic Asset Development Fund(HRADF)signed a letter in Beijing,confirming that the conditions defined in the previously signed Share Purchase Agreement(SPA)have been fulfilled.It marks a decisive achievement for COSCO SHIPPING’S
基金supported by the Special Fund for Fast Sharing of Science Paper in Net Era by the Chinese Ministry of Education, Science and Technology Development Center (Grant No.: FSSP2013044001)the Doctoral Fund of the Chinese Ministry of Education (Grant No.: 20130091110061)
文摘Purpose： This study intends to examine the factors that influence Chinese college students＇ use of the lnternet for acquiring information. Design/methodology/approach： This paper developed the research model by using the technology acceptance model （TAM） and information system success model as the theoretical foundation. The proposed model was empirically tested with the structural equation modeling technique based on data collected from a survey of 357 college students. Findings： The results show that 1） perceived ease of use, perceived usefulness and perceived playfulness all have a positive impact on the intention to use the Internet for acquiring information, 2） use context and system quality significantly influence perceived usefulness and perceived ease of use, and 3） service quality has a positive impact on perceived ease of use but not on perceived usefulness. Likewise information quality has no positive effect on perceived usefulness. Research limitations： The survey respondents were mainly from college students in Nanjing. We need to recruit college students in the western or other developing areas in China to further validate our findings. Practical implications： This study puts forward some feasible suggestions for university libraries to improve information organization and the use of digital library resources to better meet the needs of library users. Originality/value： This study provides insights into the understanding of the factors affecting college students＇ online information acquisition from multiple perspectives.
文摘Knowledge Management(KM)has become a dynamic concept for inquiry in research.The management of knowledge from multiple sources requires a systematic approach that can facilitate capturing all important aspects related to a particular discipline,several KM frameworks have been designed to serve this purpose.This research aims to propose a Collaborative Knowledge Management(CKM)Framework that bridges gaps and overcomes weaknesses in existing frameworks.The paper also validates the framework by evaluating its effectiveness for the agriculture sector of Pakistan.A software LCWU aKMS was developed which serves as a practical implementation of the concepts behind the proposed CKMF framework.LCWU aKMS served as an effective system for rice leaf disease detection and identification.It aimed to enhance CKM through knowledge sharing,lessons learned,feedback on problem resolutions,help from co-workers,collaboration,and helping communities.Data were collected from 300 rice crop farmers by questionnaires based on hypotheses.Jennex Olfman model was used to estimate the effectiveness of CKMF.Various tests were performed including frequency measures of variables,Cronbach’s alpha reliability,and Pearson’s correlation.The research provided a KMS depicting KM and collaborative features.The disease detection module was evaluated using the precision and recall method and found to be 94.16%accurate.The system could replace the work of extension agents,making it a cost and time-effective initiative for farmer betterment.
文摘Purpose： The aim of this paper is to measure the success of HISs （hospital information systems） in Bahrain from their end user’s perspectives. Methodology： a quantitative design using a questionnaire based on the DeLone and McLean Information System Success Model （2003） was employed to examine the key determinants comprise of SQ （system quality）, IQ （information quality）, SerQ （service quality） as the independent variables and their effect on the US （user satisfaction）, U （system use） and the perceived NB （net benefits） as the success measures. There are 324 respondents consisting of doctors, nurses, technicians, pharmacists and admin staff of hospitals. Data were analyzed using SPSS. Findings： SQ, IQ and SerQ are significantly positively related to US and U, and the two later are in turns significantly positively related to the perceived NB out of the system to both users and organizations. Research implications： the research reflects the experience of using innovative healthcare technologies in the Middle East and its results show the importance of improving the systems technical quality to ensure more satisfied users, more utilized technologies and to reach the optimal purpose of implementing these systems and reap out their prospected benefits. Moreover, sufficient training and full dependency on the systems are required to get more confident users and reduce the daily work load.
文摘We analyse further the reliability behaviour of series and parallel systems in the successive damage model initiated by Downton. The results are compared with those obtained for other models with different bivariate distributions.
文摘A special economic zone’s three-decade economic miracle is celebrated shenzhen, a southern coastal cityin Guangdong Province, neighboring Hong Kong, has markedits 30th anniversary as China’s first economic development zone.
