The extant literature has produced mixed evidence on the relationship between finan-cial development and ecological sustainability.This work addresses this conundrum by investigating financial development’s direct an...The extant literature has produced mixed evidence on the relationship between finan-cial development and ecological sustainability.This work addresses this conundrum by investigating financial development’s direct and indirect consequences on ecologi-cal quality utilizing the environmental Kuznets curve(EKC)methodological approach.Our empirical analysis is based on the novel dynamic autoregressive distributed lag simulations approach for South Africa between 1960 and 2020.The results,which used five distinct financial development measures,demonstrate that financial develop-ment boosts ecological integrity and environmental sustainability over the long and short terms.In the instance of South Africa,we additionally confirm the validity of the EKC theory.More importantly,the outcomes of the indirect channels demonstrate that financial development increases energy usage’s role in causing pollution while attenuating the detrimental impacts of economic growth,trade openness,and foreign direct investment on ecological quality.Moreover,the presence of an inadequate financial system is a requirement for the basis of the pollution haven hypothesis(PHH),which we examine using trade openness and foreign direct investment variables.PHH for both of these variables disappears when financial development crosses specified thresholds.Finally,industrial value addition destroys ecological quality while tech-nological innovation enhances it.This research provides some crucial policy recom-mendations and fresh perspectives for South Africa as it develops national initiatives to support ecological sustainability and reach its net zero emissions goal.展开更多
The growth and development of Jingjiang Taro [Colocasia esculenta(L.) Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germinatio...The growth and development of Jingjiang Taro [Colocasia esculenta(L.) Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germination of the second taro happened from 46 d after sprouting (7-8 leaves); the first taro began to expand, from 125 d after sprouting (12 leaves) when the the second taro was been formed; the third taro began to form from 141 to 150 d after sprouting (15-16 leaves). The fresh weight of the second and third taros quickly increased from the time of 15 leaves to harvest. Early September is a transformation term of Xiangsha taro from vegetative body dominant to corm growth dominant.展开更多
With the deepening of the market economy and the big step of urbaniza- tion, the spatial restricted effect of the development of the riverside cities in China is becoming more and more obvious. The river-crossing deve...With the deepening of the market economy and the big step of urbaniza- tion, the spatial restricted effect of the development of the riverside cities in China is becoming more and more obvious. The river-crossing development of cities is imperative. The Riverside New Area has gradually become the key area of urban development and the new economy growth pole. Based on the development history of Nanchang, the evolution of the river-crossing development of Nanchang city was analyzed systematically, and river-crossing development of Nanchang was divided into 3 stages of initial river-crossing development stage, slow river-crossing develop- ment stage and rapid river-crossing development stage. In-depth discussion was made to the dynamic mechanism of the river-crossing development in Nanchang.展开更多
The change in land development intensity is an important perspective to reflect the variation in regional social and economic development and spatial differentiation.In this paper,spatial statistical analysis,Ordinary...The change in land development intensity is an important perspective to reflect the variation in regional social and economic development and spatial differentiation.In this paper,spatial statistical analysis,Ordinary Least Squares(OLS),and Geographically weighted regression(GWR)methods are used to systematically analyse the spatial-temporal characteristics and driving forces of land development intensity for 131 spatial units in the western China from 2000 to 2015.The findings of the study are as follows:1)The land development intensity in the western China has been increasing rapidly.From 2000 to 2015,land development intensity increased by 3.4 times on average.2)The hotspot areas have shifted from central Inner Mongolia,northern Shaanxi and the Beibu Gulf of Guangxi to the Guanzhong Plain and the Chengdu-Chongqing urban agglomeration.The areas of cold spots were mainly concentrated in the Qinghai-Tibet Plateau,Yunnan,and Xinjiang.3)Investment intensity and the natural environment have always been the main drivers of land development intensity in the western China.Investment played a powerful role in promoting land development intensity,while the natural and ecological environment distinctly constrained such development.The effect of the economic factors on land development intensity in the western China has changed,which is reflected in the driving factor of construction land development shifting from economic growth in 2000 to economic structure,especially industrial structure,in 2015.展开更多
The assessment of sustainable development is crucial for constituting sustainable development strategies. Assessment methods that exist so far usually only use an indicator system for making sustainable judgement. The...The assessment of sustainable development is crucial for constituting sustainable development strategies. Assessment methods that exist so far usually only use an indicator system for making sustainable judgement. These indicators rarely reflect dynamic characteristics. However, sustainable development is influenced by changes in the social\|economic system and in the eco\|environmental system at different times. Besides the spatial character, sustainable development has a temporal character that can not be neglected; therefore the research system should also be dynamic. This paper focuses on this dynamic trait, so that the assessment results obtained provide more information for judgements in decision\|making processes. Firstly the dynamic characteristics of sustainable development are analyzed, which point to a track of sustainable development that is an upward undulating curve. According to the dynamic character and the development rules of a social, economic and ecological system, a flexible assessment approach that is based on tendency analysis, restrictive conditions and a feedback system is then proposed for sustainable development.展开更多
Miyun Reservoir was designated as the water source of Beijing City in 1982. Since that time, socio economic development in Miyun Area has been slowing due to the restriction of severe environmental standards. More and...Miyun Reservoir was designated as the water source of Beijing City in 1982. Since that time, socio economic development in Miyun Area has been slowing due to the restriction of severe environmental standards. More and more attention from the public and government has been paid to the regional sustainable development. And an effective planning for the local society management system is urgently desired. In this study, a regional sustainable development system dynamics model, named MiyunSD, is developed for supporting this planning task. MiyunSD consists of dynamic simulation models that explicitly consider information feedback that governs interactions in the system. Such models are capable of simulating the system′s behavior and predicting its developing situation of the future. For the study case, interactions among a number of system components within a time frame of fifteen years are examined dynamically. Three planning alternatives are carefully considered. The base run is based on an assumption that the existing pattern of human activities will prevail in the entire planning horizon, and the other alternatives are based on previous and present planning studies. The different alternatives will get different system′s environmental and socio economic results. Through analyzing these dynamic results, local authorities may find an optimal way to realize the objectives that the regional environment will be well protected and at the same time the economy will be rapidly developed.展开更多
With the continuous development of deep oil and gas,minerals,geothermal resources,and other resources,there are increasingly more stringent requirements for equipment.In particular,the ultra-highpressure dynamic seals...With the continuous development of deep oil and gas,minerals,geothermal resources,and other resources,there are increasingly more stringent requirements for equipment.In particular,the ultra-highpressure dynamic seals of deep mining device need to be developed.Therefore,considering the use of dynamic seals in unique deep mining environments,an ultra-high-pressure rotating combined dynamic seal was designed and developed and its sealing performance was experimentally measured and analyzed.The results show that the experimental device can operate stably under a pressure of up to150 MPa and a rotating speed of 76 r/min,and can also operate normally under a rotating speed of up to 140 r/min and a sealing pressure of 120 MPa.During the operation of the ultra-high-pressure rotating combined dynamic seal,the sealing ring does not show obvious damage,which vouches for its sealing performance.No leakage of flow and pressure was detected in the all seal structures within the sealing pressure range of 0-150 MPa.Therefore,the dynamic sealing performance of the device is intact under ultra-high-pressure conditions and can be applied in deep mining environments at a certain depth.The research and development of this device can aid future deep energy exploration and exploitation.展开更多
This paper employs system dynamics to explore how the synergy between technology management and technological capability affects new product development.The results show that the synergy between technology management ...This paper employs system dynamics to explore how the synergy between technology management and technological capability affects new product development.The results show that the synergy between technology management and technological capability has positive impact on new product development.Moreover, the leading synergy processes between technology management and technological capability in different new product development stages are different.This paper deepens the theoretical understanding of how to achieve new product development, and also provides useful guidance for firms to implement new product development.展开更多
The dynamics of blood lead (Pb-B) and blood zinc protoporphyrin (ZPP-B) of women in early pregnancy and parturient women with lead exposure and the effects on fetus development were investigated. Pb-B of lead-exposed ...The dynamics of blood lead (Pb-B) and blood zinc protoporphyrin (ZPP-B) of women in early pregnancy and parturient women with lead exposure and the effects on fetus development were investigated. Pb-B of lead-exposed women was high: 0.984 μmol/L (20.38 μg/dl) and ZPP was 84.52μg/dl. Cord blood Pb-B was 0.896 μmol/L(18.56μg/dl)and cord blood ZPP was 69.24μg/dl. In the control group, Pb-B was 0.261μmol/L(5.41μg/dl), ZPP-B, 37.59 μg/dl, cord blood, Pb-B 0.34 μmol/L (7.93 μg/dl), and cord ZPP-B 49.0μg/dl. There was a significant correlation between blood lead and blood ZPP, maternal Pb-B and cord Pb-B, maternal Pb-B and cord ZPP-B. The significance of the consistency of high level Pb-B and the effects on fetus development is discussed.展开更多
Understanding the sensitivity of tidal flats to environmental changes is challenging.Currently,most studies rely on process-based models to systematically explain the morphodynamic evolution of tidal flats.In this stu...Understanding the sensitivity of tidal flats to environmental changes is challenging.Currently,most studies rely on process-based models to systematically explain the morphodynamic evolution of tidal flats.In this study,we proposed an alternative empirical approach to explore tidal flat dynamics using statistical indices based on long-term time series of daily surface elevation development.Surface elevation dynamic(SED)indices focus on the magnitude and period of surface elevation changes,while morphodynamic signature(MDS)indices relate sediment dynamics to environmental drivers.The statistical analyses were applied to an intervention site in the Netherlands to determine the effect of recently constructed groynes on the tidal flat.Using these analyses,we were able to(1)detect a reduction in the daily SED and(2)determine that the changes in the daily SED were predominantly caused by the reduction in wave impact between the groynes rather than the reduction in tidal currents.Overall,the presented results showed that the combination of novel statistical indices provides new insights into the trajectories of tidal flats,ecosystem functioning,and sensitivity to physical drivers(wind and tides).Finally,we suggested how the SED and MDS indices may help to explore the future trajectories and climate resilience of intertidal habitats.展开更多
The Pan-1 coal mine located in Huainan municipality, Anhui province, is abundant in coal resources. In order to discover the natural conditions of gas in its coal seams, we inverted the burial history of these coal se...The Pan-1 coal mine located in Huainan municipality, Anhui province, is abundant in coal resources. In order to discover the natural conditions of gas in its coal seams, we inverted the burial history of these coal seams using the software of Easy%Ro method and simulated the development process of gas volumes and pressure of the major coal seams using CBM History Simulation Software. Our analysis shows that the devolution of gas volumes and levels of pressure can be divided into four stages: i.e., a biogas stage (P1-P3), a pyrolysis gas stage (T1-T2), an active gas enrichment stage (T3-K1) and a gas dissipating stage (K2-present). Currently, the average amounts of gas and gas pressure in coal seams Nos. 13-1, 11-2 and 8 of the Pan-1 coal mine are 8.18 m3/t and 2.20 MPa; 3.89 m3/t and 2.47 MPa and 6.35 m3/t and 2.89 MPa, respectively. This agrees very well with current mining data.展开更多
This survey is concerned with the new developments on existence and uniqueness of solutions of some basic models in atmospheric dynamics, such as two-and three-dimensional quasi-geostrophic models and three-dimensiona...This survey is concerned with the new developments on existence and uniqueness of solutions of some basic models in atmospheric dynamics, such as two-and three-dimensional quasi-geostrophic models and three-dimensional balanced model. The main aim of this paper is to introduce some results about the global and local (with respect to time) existence of solutions given by the authors in recent years, but others' important contributions and the literature on this subject are also quoted. We discuss briefly the relationships among the existence and uniqueness, physical instability and computational instability. In the appendixes, some key mathematical techniques in obtaining our results are presented, which are of vital importance to other problems in geophysical fluid dynamics as well.展开更多
Strategic management of equipment system develop-ment must attach importance to effective strategic risk manage-ment.Aiming at the identification of strategic risk of equipment system development,firstly,the source of...Strategic management of equipment system develop-ment must attach importance to effective strategic risk manage-ment.Aiming at the identification of strategic risk of equipment system development,firstly,the source of strategic risk of equip-ment system development is analyzed and classified.Based on this,a causal loop diagram of strategic risk of equipment sys-tem development based on system dynamics is established.The system dynamics analysis software Vensim PLE is used to carry out the risk influencing factors analysis,risk consequences ana-lysis,risk feedback loop identification and corresponding pre-control measures,and achieves a good risk identification effect.展开更多
With the social and economic development,conflict among the shortage of resources,environmental destruction and economic development is ever more pronounced.In this context,the circular economy was gradually accepted....With the social and economic development,conflict among the shortage of resources,environmental destruction and economic development is ever more pronounced.In this context,the circular economy was gradually accepted.Guided by sustainable development concept and promoted by six external forces,tourism circular economy take tourism micro-cycle model as the core,implement in corporate and social levels,improve resource utilization efficiency,reduce tourism's adverse impacts on the surrounding environment through recycling,reducing and reusing resources,achieve economic,social and environmental development of the organic unity.展开更多
Currently, traditional development issues, such as economic stagnation, as well as new challenges like environmental degradation and globalization, need attention. Sustainable development, including economic, environm...Currently, traditional development issues, such as economic stagnation, as well as new challenges like environmental degradation and globalization, need attention. Sustainable development, including economic, environmental, and social elements, is a main goal of decision-makers. The key to sustainable decision-making is to evaluate and forecast the status quo of sustainable development. Policy makers need a tool based on scientific information to forecast the effects of future actions on sustainability and make policies for sustainable development. This paper analyzes the relation of the economy, environment and social welfare by the grey dynamic model. The proposed method uses time series and basic indicators of ecological system, including economic, environmental and social sub-systems. It is applied to Heilongjiang Province and Jiangsu Province. The results have proved different status quo of sustainable development in these two regions, and suggestions are proposed, such as optimization of industrial structure and eco-industrial development. The conclusion is that there is no unique sustainable path, and accordingly, policy makers should choose different criteria and strategies to make efficient sustainable decisions for each region.展开更多
Fertilised eggs of the devil stringer (Inimicusjaponicus) were incubated at different salinity levels (21, 25, 29, 33, and 37), and then the hatching performances, morphological parameters, and biochemical composi...Fertilised eggs of the devil stringer (Inimicusjaponicus) were incubated at different salinity levels (21, 25, 29, 33, and 37), and then the hatching performances, morphological parameters, and biochemical composition (protein, lipid and carbohydrate) of the larvae were assayed to determine the influence of salinity on the early development ofl.japonicus. The tested salinity levels did not affect the times of hatching or mouth opening for yolk-sac larvae. However, the salinity significantly influenced the hatching and survival rates of open-mouthed larvae, as well as the morphology of yolk-sac larvae. The data indicated that 30.5 to 37.3 and 24.4 to 29.8 were suitable salinity ranges for the survival of embryos and larvae ofl.japonicus, respectively. Larvae incubated at a salinity level of 29 had the greatest full lengths, and decreasing yolk volume was positively correlated with the environmental salinity. With increasing salinity, the individual dry weights of newly hatched larvae or open-mouthed larvae decreased significantly. Newly hatched larvae incubated at a salinity level of 29 had the greatest metabolic substrate contents and gross energy levels, while the open- mouthed larvae's greatest values occurred at a salinity level of 25. Larvae incubated in the salinity range of 33 to 37 had the lowest nutritional reserves and energy values. Thus, the I.japonicus yolk-sac larvae acclimated more readily to the lower salinity level than the embryos, and higher salinity levels negatively influenced larval growth and development. In conclusion, the environmental salinity level should be maintained at 29-33 during embryogenesis and at 25-29 during early larval development for this species. Our results can be used to provide optimum aquaculture conditions for the early larval development of I.japonicus.展开更多
The smart low-carbon development of modern cities has become one of the academic hotspots.However,the dynamics is rarely involved.Therefore,TOPSIS method was used to take a quantitative study on the dynamics of smart ...The smart low-carbon development of modern cities has become one of the academic hotspots.However,the dynamics is rarely involved.Therefore,TOPSIS method was used to take a quantitative study on the dynamics of smart low-carbon development for major Chinese cities.The results showed that:(1) 3 main dynamics of smart lowcarbon city development in China are institution and culture conditions,facility and function conditions and economy and industry conditions,but the overall utility is relatively low;(2) the level of dynamic operation mechanism of smart low-carbon development for major Chinese cities is distinct between regions,indicating a spatial law of diminishing from the east to the west and differing within regions;(3) the imbalance of comprehensive dynamic mechanism and operation state between major cities is prominent,showing an urban scale law of decreasing from big to small and differing within each scale and an administration hierarchy law of descending from high to low and differing within each class;(4) 7 basic development patterns can be obtained,and most of the cities take the external strong internal weak mode,which basically matches with its development realities.展开更多
To achieve the goals of carbon peaking and carbon neutrality and maintain high-quality economic growth,China is currently striving to improve the quality of development of its power sector.In this regard,revealing the...To achieve the goals of carbon peaking and carbon neutrality and maintain high-quality economic growth,China is currently striving to improve the quality of development of its power sector.In this regard,revealing the regional differences and evolutionary trends in the development quality of China’power sector has a high value to inspire the next improvement direction toward how to integrate regional power recourses to an overall optimization level.Motived by this purpose,this paper uses the entropy method to evaluate the com‐prehensive and subsystem indices of the development quality of the power industry,and reveals their re‐gional differences and evolutionary trends with the help of the Dagum Gini coefficient and Kernel density es‐timation methods.The findings show that:There are obvious regional differences in the development quality of China’s power industry,and the differences are steadily declining in all regions except the West.Regional differences are mainly derived from inter-regional differences,with the largest inter-regional differences in the East-Northeast region.Intra-regional differences show a distribution pattern of East>West>North‐east>Center.展开更多
A project entitled‘Development of a Global High-resolution Marine Dynamic Environmental Forecasting System’has been funded by‘The Program on Marine Environmental Safety Guarantee’of The National Key Research and D...A project entitled‘Development of a Global High-resolution Marine Dynamic Environmental Forecasting System’has been funded by‘The Program on Marine Environmental Safety Guarantee’of The National Key Research and Development Program of China.This project will accomplish its objectives through basic theoretical research,model development and expansion,and system establishment and application,with a focus on four key issues separated into nine tasks.A series of research achievements have already been obtained,including datasets,observations,theories,and model results.展开更多
Microglia are the resident immune cells of the central nervous system (CNS), In the normal state, microglia have a ramified shape and con- tinuously survey the conditions of the brain.
文摘The extant literature has produced mixed evidence on the relationship between finan-cial development and ecological sustainability.This work addresses this conundrum by investigating financial development’s direct and indirect consequences on ecologi-cal quality utilizing the environmental Kuznets curve(EKC)methodological approach.Our empirical analysis is based on the novel dynamic autoregressive distributed lag simulations approach for South Africa between 1960 and 2020.The results,which used five distinct financial development measures,demonstrate that financial develop-ment boosts ecological integrity and environmental sustainability over the long and short terms.In the instance of South Africa,we additionally confirm the validity of the EKC theory.More importantly,the outcomes of the indirect channels demonstrate that financial development increases energy usage’s role in causing pollution while attenuating the detrimental impacts of economic growth,trade openness,and foreign direct investment on ecological quality.Moreover,the presence of an inadequate financial system is a requirement for the basis of the pollution haven hypothesis(PHH),which we examine using trade openness and foreign direct investment variables.PHH for both of these variables disappears when financial development crosses specified thresholds.Finally,industrial value addition destroys ecological quality while tech-nological innovation enhances it.This research provides some crucial policy recom-mendations and fresh perspectives for South Africa as it develops national initiatives to support ecological sustainability and reach its net zero emissions goal.
基金Supported by Jiangsu Self-innovation Fund for Agricultural Science and Technology[CX(12)2008]~~
文摘The growth and development of Jingjiang Taro [Colocasia esculenta(L.) Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germination of the second taro happened from 46 d after sprouting (7-8 leaves); the first taro began to expand, from 125 d after sprouting (12 leaves) when the the second taro was been formed; the third taro began to form from 141 to 150 d after sprouting (15-16 leaves). The fresh weight of the second and third taros quickly increased from the time of 15 leaves to harvest. Early September is a transformation term of Xiangsha taro from vegetative body dominant to corm growth dominant.
文摘With the deepening of the market economy and the big step of urbaniza- tion, the spatial restricted effect of the development of the riverside cities in China is becoming more and more obvious. The river-crossing development of cities is imperative. The Riverside New Area has gradually become the key area of urban development and the new economy growth pole. Based on the development history of Nanchang, the evolution of the river-crossing development of Nanchang city was analyzed systematically, and river-crossing development of Nanchang was divided into 3 stages of initial river-crossing development stage, slow river-crossing develop- ment stage and rapid river-crossing development stage. In-depth discussion was made to the dynamic mechanism of the river-crossing development in Nanchang.
基金Under the auspices of Fundamental Research Funds for the Central University(No.310827171012)National Natural Science Foundation of China(No.41971178+4 种基金3167054931170664)National Key Research&Development Program of China(2017YFC0504705)Open Fund of Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity(No.SKLESS201807)Key Research&Development Program of Shaanxi Province(No.2019SF-245)
文摘The change in land development intensity is an important perspective to reflect the variation in regional social and economic development and spatial differentiation.In this paper,spatial statistical analysis,Ordinary Least Squares(OLS),and Geographically weighted regression(GWR)methods are used to systematically analyse the spatial-temporal characteristics and driving forces of land development intensity for 131 spatial units in the western China from 2000 to 2015.The findings of the study are as follows:1)The land development intensity in the western China has been increasing rapidly.From 2000 to 2015,land development intensity increased by 3.4 times on average.2)The hotspot areas have shifted from central Inner Mongolia,northern Shaanxi and the Beibu Gulf of Guangxi to the Guanzhong Plain and the Chengdu-Chongqing urban agglomeration.The areas of cold spots were mainly concentrated in the Qinghai-Tibet Plateau,Yunnan,and Xinjiang.3)Investment intensity and the natural environment have always been the main drivers of land development intensity in the western China.Investment played a powerful role in promoting land development intensity,while the natural and ecological environment distinctly constrained such development.The effect of the economic factors on land development intensity in the western China has changed,which is reflected in the driving factor of construction land development shifting from economic growth in 2000 to economic structure,especially industrial structure,in 2015.
文摘The assessment of sustainable development is crucial for constituting sustainable development strategies. Assessment methods that exist so far usually only use an indicator system for making sustainable judgement. These indicators rarely reflect dynamic characteristics. However, sustainable development is influenced by changes in the social\|economic system and in the eco\|environmental system at different times. Besides the spatial character, sustainable development has a temporal character that can not be neglected; therefore the research system should also be dynamic. This paper focuses on this dynamic trait, so that the assessment results obtained provide more information for judgements in decision\|making processes. Firstly the dynamic characteristics of sustainable development are analyzed, which point to a track of sustainable development that is an upward undulating curve. According to the dynamic character and the development rules of a social, economic and ecological system, a flexible assessment approach that is based on tendency analysis, restrictive conditions and a feedback system is then proposed for sustainable development.
文摘Miyun Reservoir was designated as the water source of Beijing City in 1982. Since that time, socio economic development in Miyun Area has been slowing due to the restriction of severe environmental standards. More and more attention from the public and government has been paid to the regional sustainable development. And an effective planning for the local society management system is urgently desired. In this study, a regional sustainable development system dynamics model, named MiyunSD, is developed for supporting this planning task. MiyunSD consists of dynamic simulation models that explicitly consider information feedback that governs interactions in the system. Such models are capable of simulating the system′s behavior and predicting its developing situation of the future. For the study case, interactions among a number of system components within a time frame of fifteen years are examined dynamically. Three planning alternatives are carefully considered. The base run is based on an assumption that the existing pattern of human activities will prevail in the entire planning horizon, and the other alternatives are based on previous and present planning studies. The different alternatives will get different system′s environmental and socio economic results. Through analyzing these dynamic results, local authorities may find an optimal way to realize the objectives that the regional environment will be well protected and at the same time the economy will be rapidly developed.
基金supported by the Program for Guangdong Introducing Innovative and Enterpreneurial Teams(Grant No.2019ZT08G315)the National Natural Science Foundation of China(Grant No.51827901)
文摘With the continuous development of deep oil and gas,minerals,geothermal resources,and other resources,there are increasingly more stringent requirements for equipment.In particular,the ultra-highpressure dynamic seals of deep mining device need to be developed.Therefore,considering the use of dynamic seals in unique deep mining environments,an ultra-high-pressure rotating combined dynamic seal was designed and developed and its sealing performance was experimentally measured and analyzed.The results show that the experimental device can operate stably under a pressure of up to150 MPa and a rotating speed of 76 r/min,and can also operate normally under a rotating speed of up to 140 r/min and a sealing pressure of 120 MPa.During the operation of the ultra-high-pressure rotating combined dynamic seal,the sealing ring does not show obvious damage,which vouches for its sealing performance.No leakage of flow and pressure was detected in the all seal structures within the sealing pressure range of 0-150 MPa.Therefore,the dynamic sealing performance of the device is intact under ultra-high-pressure conditions and can be applied in deep mining environments at a certain depth.The research and development of this device can aid future deep energy exploration and exploitation.
基金supported by the Heilongjiang Philosophy and Social Science Research Project (19GLB087)。
文摘This paper employs system dynamics to explore how the synergy between technology management and technological capability affects new product development.The results show that the synergy between technology management and technological capability has positive impact on new product development.Moreover, the leading synergy processes between technology management and technological capability in different new product development stages are different.This paper deepens the theoretical understanding of how to achieve new product development, and also provides useful guidance for firms to implement new product development.
文摘The dynamics of blood lead (Pb-B) and blood zinc protoporphyrin (ZPP-B) of women in early pregnancy and parturient women with lead exposure and the effects on fetus development were investigated. Pb-B of lead-exposed women was high: 0.984 μmol/L (20.38 μg/dl) and ZPP was 84.52μg/dl. Cord blood Pb-B was 0.896 μmol/L(18.56μg/dl)and cord blood ZPP was 69.24μg/dl. In the control group, Pb-B was 0.261μmol/L(5.41μg/dl), ZPP-B, 37.59 μg/dl, cord blood, Pb-B 0.34 μmol/L (7.93 μg/dl), and cord ZPP-B 49.0μg/dl. There was a significant correlation between blood lead and blood ZPP, maternal Pb-B and cord Pb-B, maternal Pb-B and cord ZPP-B. The significance of the consistency of high level Pb-B and the effects on fetus development is discussed.
基金supported by the Royal Netherlands Academy of Arts and Sciences(KNAW)(Grant No.PSA-SA-E-02)the Province of Zeeland,the Netherlands(Grant No.CoE-Buitendijks)。
文摘Understanding the sensitivity of tidal flats to environmental changes is challenging.Currently,most studies rely on process-based models to systematically explain the morphodynamic evolution of tidal flats.In this study,we proposed an alternative empirical approach to explore tidal flat dynamics using statistical indices based on long-term time series of daily surface elevation development.Surface elevation dynamic(SED)indices focus on the magnitude and period of surface elevation changes,while morphodynamic signature(MDS)indices relate sediment dynamics to environmental drivers.The statistical analyses were applied to an intervention site in the Netherlands to determine the effect of recently constructed groynes on the tidal flat.Using these analyses,we were able to(1)detect a reduction in the daily SED and(2)determine that the changes in the daily SED were predominantly caused by the reduction in wave impact between the groynes rather than the reduction in tidal currents.Overall,the presented results showed that the combination of novel statistical indices provides new insights into the trajectories of tidal flats,ecosystem functioning,and sensitivity to physical drivers(wind and tides).Finally,we suggested how the SED and MDS indices may help to explore the future trajectories and climate resilience of intertidal habitats.
基金Project 2005CB221501 supported by the National Basic Research Program of China
文摘The Pan-1 coal mine located in Huainan municipality, Anhui province, is abundant in coal resources. In order to discover the natural conditions of gas in its coal seams, we inverted the burial history of these coal seams using the software of Easy%Ro method and simulated the development process of gas volumes and pressure of the major coal seams using CBM History Simulation Software. Our analysis shows that the devolution of gas volumes and levels of pressure can be divided into four stages: i.e., a biogas stage (P1-P3), a pyrolysis gas stage (T1-T2), an active gas enrichment stage (T3-K1) and a gas dissipating stage (K2-present). Currently, the average amounts of gas and gas pressure in coal seams Nos. 13-1, 11-2 and 8 of the Pan-1 coal mine are 8.18 m3/t and 2.20 MPa; 3.89 m3/t and 2.47 MPa and 6.35 m3/t and 2.89 MPa, respectively. This agrees very well with current mining data.
文摘This survey is concerned with the new developments on existence and uniqueness of solutions of some basic models in atmospheric dynamics, such as two-and three-dimensional quasi-geostrophic models and three-dimensional balanced model. The main aim of this paper is to introduce some results about the global and local (with respect to time) existence of solutions given by the authors in recent years, but others' important contributions and the literature on this subject are also quoted. We discuss briefly the relationships among the existence and uniqueness, physical instability and computational instability. In the appendixes, some key mathematical techniques in obtaining our results are presented, which are of vital importance to other problems in geophysical fluid dynamics as well.
文摘Strategic management of equipment system develop-ment must attach importance to effective strategic risk manage-ment.Aiming at the identification of strategic risk of equipment system development,firstly,the source of strategic risk of equip-ment system development is analyzed and classified.Based on this,a causal loop diagram of strategic risk of equipment sys-tem development based on system dynamics is established.The system dynamics analysis software Vensim PLE is used to carry out the risk influencing factors analysis,risk consequences ana-lysis,risk feedback loop identification and corresponding pre-control measures,and achieves a good risk identification effect.
文摘With the social and economic development,conflict among the shortage of resources,environmental destruction and economic development is ever more pronounced.In this context,the circular economy was gradually accepted.Guided by sustainable development concept and promoted by six external forces,tourism circular economy take tourism micro-cycle model as the core,implement in corporate and social levels,improve resource utilization efficiency,reduce tourism's adverse impacts on the surrounding environment through recycling,reducing and reusing resources,achieve economic,social and environmental development of the organic unity.
文摘Currently, traditional development issues, such as economic stagnation, as well as new challenges like environmental degradation and globalization, need attention. Sustainable development, including economic, environmental, and social elements, is a main goal of decision-makers. The key to sustainable decision-making is to evaluate and forecast the status quo of sustainable development. Policy makers need a tool based on scientific information to forecast the effects of future actions on sustainability and make policies for sustainable development. This paper analyzes the relation of the economy, environment and social welfare by the grey dynamic model. The proposed method uses time series and basic indicators of ecological system, including economic, environmental and social sub-systems. It is applied to Heilongjiang Province and Jiangsu Province. The results have proved different status quo of sustainable development in these two regions, and suggestions are proposed, such as optimization of industrial structure and eco-industrial development. The conclusion is that there is no unique sustainable path, and accordingly, policy makers should choose different criteria and strategies to make efficient sustainable decisions for each region.
基金Supported by the Innovation Project of the Shanghai Education Commission,China(No.12ZZ166)the Shanghai Universities First-Class Disciplines Project of Fisheries
文摘Fertilised eggs of the devil stringer (Inimicusjaponicus) were incubated at different salinity levels (21, 25, 29, 33, and 37), and then the hatching performances, morphological parameters, and biochemical composition (protein, lipid and carbohydrate) of the larvae were assayed to determine the influence of salinity on the early development ofl.japonicus. The tested salinity levels did not affect the times of hatching or mouth opening for yolk-sac larvae. However, the salinity significantly influenced the hatching and survival rates of open-mouthed larvae, as well as the morphology of yolk-sac larvae. The data indicated that 30.5 to 37.3 and 24.4 to 29.8 were suitable salinity ranges for the survival of embryos and larvae ofl.japonicus, respectively. Larvae incubated at a salinity level of 29 had the greatest full lengths, and decreasing yolk volume was positively correlated with the environmental salinity. With increasing salinity, the individual dry weights of newly hatched larvae or open-mouthed larvae decreased significantly. Newly hatched larvae incubated at a salinity level of 29 had the greatest metabolic substrate contents and gross energy levels, while the open- mouthed larvae's greatest values occurred at a salinity level of 25. Larvae incubated in the salinity range of 33 to 37 had the lowest nutritional reserves and energy values. Thus, the I.japonicus yolk-sac larvae acclimated more readily to the lower salinity level than the embryos, and higher salinity levels negatively influenced larval growth and development. In conclusion, the environmental salinity level should be maintained at 29-33 during embryogenesis and at 25-29 during early larval development for this species. Our results can be used to provide optimum aquaculture conditions for the early larval development of I.japonicus.
基金the funding support from the Project supported by the State Key Program of National Natural Science of China(71433008)
文摘The smart low-carbon development of modern cities has become one of the academic hotspots.However,the dynamics is rarely involved.Therefore,TOPSIS method was used to take a quantitative study on the dynamics of smart low-carbon development for major Chinese cities.The results showed that:(1) 3 main dynamics of smart lowcarbon city development in China are institution and culture conditions,facility and function conditions and economy and industry conditions,but the overall utility is relatively low;(2) the level of dynamic operation mechanism of smart low-carbon development for major Chinese cities is distinct between regions,indicating a spatial law of diminishing from the east to the west and differing within regions;(3) the imbalance of comprehensive dynamic mechanism and operation state between major cities is prominent,showing an urban scale law of decreasing from big to small and differing within each scale and an administration hierarchy law of descending from high to low and differing within each class;(4) 7 basic development patterns can be obtained,and most of the cities take the external strong internal weak mode,which basically matches with its development realities.
基金supported by National Natural Science Foundation of China[Grant number.71673034]Postdoctoral Research Founda‐tion of China[Grant number.2021M692654]+1 种基金Natural Science Basic Research Program of Shaanxi Province[Grant number.2020JQ282]Social Science Foundation of Shaanxi Province[Grant number.2020R042].
文摘To achieve the goals of carbon peaking and carbon neutrality and maintain high-quality economic growth,China is currently striving to improve the quality of development of its power sector.In this regard,revealing the regional differences and evolutionary trends in the development quality of China’power sector has a high value to inspire the next improvement direction toward how to integrate regional power recourses to an overall optimization level.Motived by this purpose,this paper uses the entropy method to evaluate the com‐prehensive and subsystem indices of the development quality of the power industry,and reveals their re‐gional differences and evolutionary trends with the help of the Dagum Gini coefficient and Kernel density es‐timation methods.The findings show that:There are obvious regional differences in the development quality of China’s power industry,and the differences are steadily declining in all regions except the West.Regional differences are mainly derived from inter-regional differences,with the largest inter-regional differences in the East-Northeast region.Intra-regional differences show a distribution pattern of East>West>North‐east>Center.
基金funded by "The Program on Marine Environmental Safety Guarantee" of "The National Key Research and Development Program of China"[grant number2016YFC1401409]
文摘A project entitled‘Development of a Global High-resolution Marine Dynamic Environmental Forecasting System’has been funded by‘The Program on Marine Environmental Safety Guarantee’of The National Key Research and Development Program of China.This project will accomplish its objectives through basic theoretical research,model development and expansion,and system establishment and application,with a focus on four key issues separated into nine tasks.A series of research achievements have already been obtained,including datasets,observations,theories,and model results.
文摘Microglia are the resident immune cells of the central nervous system (CNS), In the normal state, microglia have a ramified shape and con- tinuously survey the conditions of the brain.