[Objective] The study aimed to investigate the changes of water status and different responses of osmoregulants during air-drought stress,to better understand mechanisms of drought resistance in Jatropha Curcas L. [Me...[Objective] The study aimed to investigate the changes of water status and different responses of osmoregulants during air-drought stress,to better understand mechanisms of drought resistance in Jatropha Curcas L. [Methods] The 12-day-old J. curcas seedlings were held in a climate chamber at 25/20 ℃(day/night),16 hours illumination,and 75% of relative humidity for air-drought treatment,and the changes of water potential,osmotic potential and the content of soluble sugar,proline,betaine were measured. [Results] Water potential and osmotic potential in leaves of J. curcas seedlings dropped significantly,pressure potential lost during air-drought stress,and the contents of osmoregulants soluble sugar,proline and betaine rose significantly to different extent in the leaves and stems. [Conclusion] Osmoregulants in the leaves and stems respond differently to air-drought stress,and in general leaves are much more responsive to the drought than stems of J. curcas seedlings.展开更多
In this paper we study the following nonlinear BSDE:y(t) + ∫1 t f(s,y(s),z(s))ds + ∫1 t [z(s) + g 1 (s,y(s)) + εg 2 (s,y(s),z(s))]dW s=ξ,t ∈ [0,1],where ε is a small parameter.The coeffi...In this paper we study the following nonlinear BSDE:y(t) + ∫1 t f(s,y(s),z(s))ds + ∫1 t [z(s) + g 1 (s,y(s)) + εg 2 (s,y(s),z(s))]dW s=ξ,t ∈ [0,1],where ε is a small parameter.The coefficient f is locally Lipschitz in y and z,the coefficient g 1 is locally Lipschitz in y,and the coefficient g 2 is uniformly Lipschitz in y and z.Let L N be the locally Lipschitz constant of the coefficients on the ball B(0,N) of R d × R d×r.We prove the existence and uniqueness of the solution when L N ~ √ log N and the parameter ε is small.展开更多
In this paper, more efficient, low-complexity and reliable region of interest (ROI) image codec for compressing smooth low texture remote sensing images is proposed. We explore the efficiency of the modified RO! cod...In this paper, more efficient, low-complexity and reliable region of interest (ROI) image codec for compressing smooth low texture remote sensing images is proposed. We explore the efficiency of the modified RO! codec with respect to the selected set of convenient wavelet filters, which is a novel method. Such ROI coding experiment analysis representing low bit rate lossy to high quality lossless reconstruction with timing analysis is useful for improving remote sensing ground truth surveillance efficiency in terms of time and quality. The subjective [i.e. fair, five observer (HVS) evaluations using enhanced 3D picture view Hyper memory display technology] and the objective results revealed that for faster ground truth ROI coding applications, the Symlet-4 adaptation performs better than Biorthogonal 4.4 and Biorthogonal 6.8. However, the discrete Meyer wavelet adaptation is the best solution for delayed ROI image reconstructions.展开更多
Small and medium enterprises are the main institutional medium of the European economy. This is also recognized by the government of the Republic of Croatia, which emphasizes their importance and values their dynamism...Small and medium enterprises are the main institutional medium of the European economy. This is also recognized by the government of the Republic of Croatia, which emphasizes their importance and values their dynamism and capability for revitalizing the Croatian economy, and supports this by ways of subsidies. But, for all the effort, the economic position of small and medium enterprises in the terms of globalization is becoming more complex and uncertain, limited by time and more demanding. This does not correspond with the thesis which states that in the environment and conditions of the modem market economy, which is dynamised by progress in science, technology, information and communication, entrepreneurship has manifested a progressive dimension with the character and needs of all economic activity, as well as a tendency to achieve set objectives and generate change. Recently, after the repeated recession, which was encumbered by the effects of the one before, the conditions of doing business and survival for small and medium enterprises have changed significantly in a negative sense. So, there is a justified cause for questioning earlier stances about small and medium enterprises and their capability to be a motor of development of the Croatian economy, as well as to reevaluate their influence in the context of GDP growth, to focus on the importance and prevalence of certain sectors of the economy, to critically evaluate economic measures which do not lead to a reduction in unemployment and to define the requirements for future development of the small and medium enterprises, which implicates the increased economic efficiency, quality and living standards.展开更多
With the proliferation of small and mini drones, Drone Small Cells(DSCs) can cooperative multiple drones to provide communication service for ground users as emergency means or supplementary ones of traditional terres...With the proliferation of small and mini drones, Drone Small Cells(DSCs) can cooperative multiple drones to provide communication service for ground users as emergency means or supplementary ones of traditional terrestrial cellular networks. In this paper, we study the fundamental problem of optimizing the deployment density of DSCs to achieve the maximum coverage performance. Most related works do not consider cumulative inter-cell interference when studying the coverage performance of DSCs. First, we derive an approximate and closed-form expression of the cumulative inter-cell interference which comes from both probabilistic Line-of-Sight(Lo S) and Non-Line-of-Sight(NLo S) links. Then, we analyze the coverage performance of DSCs and derive the transcendental function of optimal deployment density to obtain the maximum coverage. Last, we propose an algorithm to get the optimal deployment density with low complexity. We conduct both field experiments and Matlab simulations to verify the correctness of theoretical analysis. In addition, we show the impact of some factors on the relation between the deployment density and coverage performance through extensive numerical simulations.展开更多
International agencies and scientific research have been calling for the inclusion of children in disaster preparedness and risk reduction, to hear their voices in order to address their specific needs and vulnerabili...International agencies and scientific research have been calling for the inclusion of children in disaster preparedness and risk reduction, to hear their voices in order to address their specific needs and vulnerabilities and harness their capabilities in terms of building community resilience. This article assesses the roles ascribed to children in policy and education for disaster risk reduction in Portugal. The approach is based on a scoping methodology that encompasses document analysis and interviews with national and local stakeholders and policymakers in the disaster risk reduction field. The research is carried out within the scope of a European funded project, CUIDAR Cultures of Disaster Resilience among Children and Young People. More specifically, the article provides an overview of the discourses on the roles ascribed to children in urban disaster risk reduction(DRR). The authors maintain that although children are often taken as a target group in urban disaster prevention and management, they are seldom considered in terms of active participation in disaster risk reduction programs in the Portuguese context. Nevertheless, our analysis shows that there is a growing awareness of the relevance of active participation by children in order to create successful DRR.展开更多
The flow field distribution in centrifugal compressor is significantly affected by the non-axisymmetric geometry structure of the volute.The experimental and numerical simulation methods were adopted in this work to s...The flow field distribution in centrifugal compressor is significantly affected by the non-axisymmetric geometry structure of the volute.The experimental and numerical simulation methods were adopted in this work to study the compressor flow field distribution with different flow conditions.The results show that the pressure distribution in volute is characterized by the circumferential non-uniform phenomenon and the pressure fluctuation on the high static pressure zone propagates reversely to upstream,which results in the non-axisymmetric flow inside the compressor.The non-uniform level of pressure distribution in large flow condition is higher than that in small flow condition,its effect on the upstream flow field is also stronger.Additionally,the non-uniform circumferential pressure distribution in volute brings the non-axisymmetric flow at impeller outlet.In different flow conditions,the circumferential variation of the absolute flow angle at impeller outlet is also different.Meanwhile,the non-axisymmetric flow characteristics in internal impeller can be also reflected by the distribution of the mass flow.The high static pressure region of the volute corresponds to the decrease of mass flow in upstream blade channel,while the low static pressure zone of the volute corresponds to the increase of the mass flow.In small flow condition,the mass flow difference in the blade channel is bigger than that in the large flow condition.展开更多
To reduce the fuel consumption of internal combustion engines, more attention has been paid to the tribological performance of the piston ring pack during the cold start and idle operations. In this research, a numeri...To reduce the fuel consumption of internal combustion engines, more attention has been paid to the tribological performance of the piston ring pack during the cold start and idle operations. In this research, a numerical model considering the cylinder liner deformation and the piston ring conformability is developed to predict the blow-by, lubrication, friction and wear of the piston ring pack under different operating conditions. The gas flow rate, inter-ring gas pressures, minimum oil film thickness, frictional force and wear load during cold start are calculated and compared with those during warm idle operating conditions. The results show that cylinder liner deformation and piston ring conformability together obviously affect blow-by and other tribological performance. Meanwhile, it is found that friction loss is larger during cold start than during warm idle operating conditions. However, the wear process is more severe during warm idle operation than during cold start. From this research, the blow-by and tribological performance of the piston ring pack during cold start and warm idle operations are understood more deeply.展开更多
基金Supported by Special Key R&D Fund from Yunnan Provincial Department of Education (ZD2010004)~~
文摘[Objective] The study aimed to investigate the changes of water status and different responses of osmoregulants during air-drought stress,to better understand mechanisms of drought resistance in Jatropha Curcas L. [Methods] The 12-day-old J. curcas seedlings were held in a climate chamber at 25/20 ℃(day/night),16 hours illumination,and 75% of relative humidity for air-drought treatment,and the changes of water potential,osmotic potential and the content of soluble sugar,proline,betaine were measured. [Results] Water potential and osmotic potential in leaves of J. curcas seedlings dropped significantly,pressure potential lost during air-drought stress,and the contents of osmoregulants soluble sugar,proline and betaine rose significantly to different extent in the leaves and stems. [Conclusion] Osmoregulants in the leaves and stems respond differently to air-drought stress,and in general leaves are much more responsive to the drought than stems of J. curcas seedlings.
文摘In this paper we study the following nonlinear BSDE:y(t) + ∫1 t f(s,y(s),z(s))ds + ∫1 t [z(s) + g 1 (s,y(s)) + εg 2 (s,y(s),z(s))]dW s=ξ,t ∈ [0,1],where ε is a small parameter.The coefficient f is locally Lipschitz in y and z,the coefficient g 1 is locally Lipschitz in y,and the coefficient g 2 is uniformly Lipschitz in y and z.Let L N be the locally Lipschitz constant of the coefficients on the ball B(0,N) of R d × R d×r.We prove the existence and uniqueness of the solution when L N ~ √ log N and the parameter ε is small.
基金Project (No. 2004144013) supported by the Chinese Government Scholarship Council, China
文摘In this paper, more efficient, low-complexity and reliable region of interest (ROI) image codec for compressing smooth low texture remote sensing images is proposed. We explore the efficiency of the modified RO! codec with respect to the selected set of convenient wavelet filters, which is a novel method. Such ROI coding experiment analysis representing low bit rate lossy to high quality lossless reconstruction with timing analysis is useful for improving remote sensing ground truth surveillance efficiency in terms of time and quality. The subjective [i.e. fair, five observer (HVS) evaluations using enhanced 3D picture view Hyper memory display technology] and the objective results revealed that for faster ground truth ROI coding applications, the Symlet-4 adaptation performs better than Biorthogonal 4.4 and Biorthogonal 6.8. However, the discrete Meyer wavelet adaptation is the best solution for delayed ROI image reconstructions.
文摘Small and medium enterprises are the main institutional medium of the European economy. This is also recognized by the government of the Republic of Croatia, which emphasizes their importance and values their dynamism and capability for revitalizing the Croatian economy, and supports this by ways of subsidies. But, for all the effort, the economic position of small and medium enterprises in the terms of globalization is becoming more complex and uncertain, limited by time and more demanding. This does not correspond with the thesis which states that in the environment and conditions of the modem market economy, which is dynamised by progress in science, technology, information and communication, entrepreneurship has manifested a progressive dimension with the character and needs of all economic activity, as well as a tendency to achieve set objectives and generate change. Recently, after the repeated recession, which was encumbered by the effects of the one before, the conditions of doing business and survival for small and medium enterprises have changed significantly in a negative sense. So, there is a justified cause for questioning earlier stances about small and medium enterprises and their capability to be a motor of development of the Croatian economy, as well as to reevaluate their influence in the context of GDP growth, to focus on the importance and prevalence of certain sectors of the economy, to critically evaluate economic measures which do not lead to a reduction in unemployment and to define the requirements for future development of the small and medium enterprises, which implicates the increased economic efficiency, quality and living standards.
基金supported in part by National NSF of China under Grant No.61472445,No.61631020,No.61702525 and No.61702545in part by the NSF of Jiangsu Province under Grant No.BK20140076.5
文摘With the proliferation of small and mini drones, Drone Small Cells(DSCs) can cooperative multiple drones to provide communication service for ground users as emergency means or supplementary ones of traditional terrestrial cellular networks. In this paper, we study the fundamental problem of optimizing the deployment density of DSCs to achieve the maximum coverage performance. Most related works do not consider cumulative inter-cell interference when studying the coverage performance of DSCs. First, we derive an approximate and closed-form expression of the cumulative inter-cell interference which comes from both probabilistic Line-of-Sight(Lo S) and Non-Line-of-Sight(NLo S) links. Then, we analyze the coverage performance of DSCs and derive the transcendental function of optimal deployment density to obtain the maximum coverage. Last, we propose an algorithm to get the optimal deployment density with low complexity. We conduct both field experiments and Matlab simulations to verify the correctness of theoretical analysis. In addition, we show the impact of some factors on the relation between the deployment density and coverage performance through extensive numerical simulations.
基金The CUIDAR project-CUIDAR Cultures of Disaster Resilience among Children and Young People-has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No.653753
文摘International agencies and scientific research have been calling for the inclusion of children in disaster preparedness and risk reduction, to hear their voices in order to address their specific needs and vulnerabilities and harness their capabilities in terms of building community resilience. This article assesses the roles ascribed to children in policy and education for disaster risk reduction in Portugal. The approach is based on a scoping methodology that encompasses document analysis and interviews with national and local stakeholders and policymakers in the disaster risk reduction field. The research is carried out within the scope of a European funded project, CUIDAR Cultures of Disaster Resilience among Children and Young People. More specifically, the article provides an overview of the discourses on the roles ascribed to children in urban disaster risk reduction(DRR). The authors maintain that although children are often taken as a target group in urban disaster prevention and management, they are seldom considered in terms of active participation in disaster risk reduction programs in the Portuguese context. Nevertheless, our analysis shows that there is a growing awareness of the relevance of active participation by children in order to create successful DRR.
基金sponsored by the National Natural Science Foundation of China(No.51276017)
文摘The flow field distribution in centrifugal compressor is significantly affected by the non-axisymmetric geometry structure of the volute.The experimental and numerical simulation methods were adopted in this work to study the compressor flow field distribution with different flow conditions.The results show that the pressure distribution in volute is characterized by the circumferential non-uniform phenomenon and the pressure fluctuation on the high static pressure zone propagates reversely to upstream,which results in the non-axisymmetric flow inside the compressor.The non-uniform level of pressure distribution in large flow condition is higher than that in small flow condition,its effect on the upstream flow field is also stronger.Additionally,the non-uniform circumferential pressure distribution in volute brings the non-axisymmetric flow at impeller outlet.In different flow conditions,the circumferential variation of the absolute flow angle at impeller outlet is also different.Meanwhile,the non-axisymmetric flow characteristics in internal impeller can be also reflected by the distribution of the mass flow.The high static pressure region of the volute corresponds to the decrease of mass flow in upstream blade channel,while the low static pressure zone of the volute corresponds to the increase of the mass flow.In small flow condition,the mass flow difference in the blade channel is bigger than that in the large flow condition.
基金supported by the National Natural Science Foundation of China(Grant No.51375300)the Research Project of State Key Laboratory of Mechanical System and Vibration(Grant No.MSVZD201401)
文摘To reduce the fuel consumption of internal combustion engines, more attention has been paid to the tribological performance of the piston ring pack during the cold start and idle operations. In this research, a numerical model considering the cylinder liner deformation and the piston ring conformability is developed to predict the blow-by, lubrication, friction and wear of the piston ring pack under different operating conditions. The gas flow rate, inter-ring gas pressures, minimum oil film thickness, frictional force and wear load during cold start are calculated and compared with those during warm idle operating conditions. The results show that cylinder liner deformation and piston ring conformability together obviously affect blow-by and other tribological performance. Meanwhile, it is found that friction loss is larger during cold start than during warm idle operating conditions. However, the wear process is more severe during warm idle operation than during cold start. From this research, the blow-by and tribological performance of the piston ring pack during cold start and warm idle operations are understood more deeply.