Integrated water and fertilizer management is important for promoting sustainable development of facility agriculture,and biochar plays an important role in guaranteeing food production,as well as alleviating water sh...Integrated water and fertilizer management is important for promoting sustainable development of facility agriculture,and biochar plays an important role in guaranteeing food production,as well as alleviating water shortages and the overuse of fertilizers.The field experiment had twelve treatments and a control(CK)trial including two irrigation amounts(I1,100%ETm;I2,60%ETm;where ETm is the maximum evapotranspiration),two nitrogen applications(N1,360 kg ha^(−1);N2,120 kg ha^(−1))and three biochar application levels(B1,60 t ha^(−1);B_(2),30 t ha^(−1)and B3,0 t ha^(−1)).A multi-objective synergistic irrigation-nitrogen-biochar application system for improving tomato yield,quality,water and nitrogen use efficiency,and greenhouse emissions was developed by integrating the techniques of experimentation and optimization.First,a coupled irrigation-nitrogen-biochar plot experiment was arranged.Then,tomato yield and fruit quality parameters were determined experimentally to establish the response relationships between irrigation-nitrogen-biochar dosage and yield,comprehensive quality of tomatoes(TCQ),irrigation water use efficiency(IWUE),partial factor productivity of nitrogen(PFPN),and net greenhouse gas emissions(NGE).Finally,a multi-objective dynamic optimization regulation model of irrigation-nitrogen-biochar resource allocation at different growth stages of tomato was constructed which was solved by the fuzzy programming method.The results showed that the application of irrigation and nitrogen to biochar promoted increase in yield,IWUE and PFPN,while it had an inhibitory effect on NGE.In addition,the optimal allocation amounts of water and fertilizer were different under different scenarios.The yield of the S1 scenario increased by 8.31%compared to the B_(1)I_(1)N_(2) treatment;TCQ of the S2 scenario increased by 5.14%compared to the B_(2)I_(2)N_(1) treatment;IWUE of the S3 scenario increased by 10.01%compared to the B1I2N2 treatment;PFPN of the S4 scenario increased by 9.35%compared to the B_(1)I_(1)N_(2) treatment;and NGE of the S5 scenario decreased by 11.23%compared to the B_(2)I1N1 treatment.The optimization model showed that the coordination of multiple objectives considering yield,TCQ,IWUE,PFPN,and NGE increased on average from 4.44 to 69.02%compared to each treatment when the irrigation-nitrogen-biochar dosage was 205.18 mm,186 kg ha^(−1)and 43.31 t ha^(−1),respectively.This study provides a guiding basis for the sustainable management of water and fertilizer in greenhouse tomato production under drip irrigation fertilization conditions.展开更多
The motivation in public-private partnerships （PPPs） is to harness the strengths of public and private partners to deliver essential public services. The ability to transfer risk to the private sector in PPP has bee...The motivation in public-private partnerships （PPPs） is to harness the strengths of public and private partners to deliver essential public services. The ability to transfer risk to the private sector in PPP has been one of the reasons why the public sector relies on the private sector to participate in the development of infrastructure projects. In most instances, the public sector also believes that the private sector can fund the project at a lower cost. The private sector on the other hand, believes that they could achieve a strong financial return based on the concessions that the public sector will provide. If the sectors feel altruistic empathy to each other, they will realize that their original goals are not achievable. However, having understood the other sector＇s needs and constraints, collaborative negotiation will yield a set of common goals. There are no commonly agreed frameworks on collaborative negotiation before PPP is formally established. The objective of this paper is to use deductive analysis to develop a conceptual framework for inquiring into the motivations of the public and private sectors during negotiation. This framework will provide insights on the extent of altruistic empathy of both sectors at the onset and how this altruistic empathy frames collaborative negotiation. This paper shows that collaborative negotiation will influence the success of partnerships and altruistic empathy is an important preamble to collaborative negotiation. This paper provides a frame of reference for future study using other research methods for further validation.展开更多
The public-private partnership has been in use in the world for over 40 years, and has been growing at a varying rate and with mixed success in different countries. Based on the experience gained in selected countries...The public-private partnership has been in use in the world for over 40 years, and has been growing at a varying rate and with mixed success in different countries. Based on the experience gained in selected countries, this article shows key success factors of the public-private partnership.展开更多
Comprehensive river regulation in the new era is a series of construction procedures from planning,scheme generation and engineering design to commercial pattern,construction and operation,etc.,which is a comprehensiv...Comprehensive river regulation in the new era is a series of construction procedures from planning,scheme generation and engineering design to commercial pattern,construction and operation,etc.,which is a comprehensive project coordinated and managed by multiple departments.Different industry departments measure the feasibility of scheme design according to the standards of their own departments in the examination of river regulation,but due to the lack of understanding of other industry standards,some unnecessary scheme contradictions are often caused in the cross-industry cooperation.The study integrates and sorts out specifi cations of various departments involved in river regulation,and performs analogy study of standards of various contents in multi-industry cooperation with contents of comprehensive river regulation as the scale,so as to promote cross-industry communication of comprehensive river regulation and promote construction of integrated river regulation platform.展开更多
基金supported by the National Natural Science Foundation of China(52222902 and 52079029)。
文摘Integrated water and fertilizer management is important for promoting sustainable development of facility agriculture,and biochar plays an important role in guaranteeing food production,as well as alleviating water shortages and the overuse of fertilizers.The field experiment had twelve treatments and a control(CK)trial including two irrigation amounts(I1,100%ETm;I2,60%ETm;where ETm is the maximum evapotranspiration),two nitrogen applications(N1,360 kg ha^(−1);N2,120 kg ha^(−1))and three biochar application levels(B1,60 t ha^(−1);B_(2),30 t ha^(−1)and B3,0 t ha^(−1)).A multi-objective synergistic irrigation-nitrogen-biochar application system for improving tomato yield,quality,water and nitrogen use efficiency,and greenhouse emissions was developed by integrating the techniques of experimentation and optimization.First,a coupled irrigation-nitrogen-biochar plot experiment was arranged.Then,tomato yield and fruit quality parameters were determined experimentally to establish the response relationships between irrigation-nitrogen-biochar dosage and yield,comprehensive quality of tomatoes(TCQ),irrigation water use efficiency(IWUE),partial factor productivity of nitrogen(PFPN),and net greenhouse gas emissions(NGE).Finally,a multi-objective dynamic optimization regulation model of irrigation-nitrogen-biochar resource allocation at different growth stages of tomato was constructed which was solved by the fuzzy programming method.The results showed that the application of irrigation and nitrogen to biochar promoted increase in yield,IWUE and PFPN,while it had an inhibitory effect on NGE.In addition,the optimal allocation amounts of water and fertilizer were different under different scenarios.The yield of the S1 scenario increased by 8.31%compared to the B_(1)I_(1)N_(2) treatment;TCQ of the S2 scenario increased by 5.14%compared to the B_(2)I_(2)N_(1) treatment;IWUE of the S3 scenario increased by 10.01%compared to the B1I2N2 treatment;PFPN of the S4 scenario increased by 9.35%compared to the B_(1)I_(1)N_(2) treatment;and NGE of the S5 scenario decreased by 11.23%compared to the B_(2)I1N1 treatment.The optimization model showed that the coordination of multiple objectives considering yield,TCQ,IWUE,PFPN,and NGE increased on average from 4.44 to 69.02%compared to each treatment when the irrigation-nitrogen-biochar dosage was 205.18 mm,186 kg ha^(−1)and 43.31 t ha^(−1),respectively.This study provides a guiding basis for the sustainable management of water and fertilizer in greenhouse tomato production under drip irrigation fertilization conditions.
文摘The motivation in public-private partnerships （PPPs） is to harness the strengths of public and private partners to deliver essential public services. The ability to transfer risk to the private sector in PPP has been one of the reasons why the public sector relies on the private sector to participate in the development of infrastructure projects. In most instances, the public sector also believes that the private sector can fund the project at a lower cost. The private sector on the other hand, believes that they could achieve a strong financial return based on the concessions that the public sector will provide. If the sectors feel altruistic empathy to each other, they will realize that their original goals are not achievable. However, having understood the other sector＇s needs and constraints, collaborative negotiation will yield a set of common goals. There are no commonly agreed frameworks on collaborative negotiation before PPP is formally established. The objective of this paper is to use deductive analysis to develop a conceptual framework for inquiring into the motivations of the public and private sectors during negotiation. This framework will provide insights on the extent of altruistic empathy of both sectors at the onset and how this altruistic empathy frames collaborative negotiation. This paper shows that collaborative negotiation will influence the success of partnerships and altruistic empathy is an important preamble to collaborative negotiation. This paper provides a frame of reference for future study using other research methods for further validation.
文摘The public-private partnership has been in use in the world for over 40 years, and has been growing at a varying rate and with mixed success in different countries. Based on the experience gained in selected countries, this article shows key success factors of the public-private partnership.
基金Interdisciplinary Research Projects of the Fundamental Research Funds for the Central Universities(DUT19JC55)High-level Talents Innovation Support Project of Dalian City(2017RQ076).
文摘Comprehensive river regulation in the new era is a series of construction procedures from planning,scheme generation and engineering design to commercial pattern,construction and operation,etc.,which is a comprehensive project coordinated and managed by multiple departments.Different industry departments measure the feasibility of scheme design according to the standards of their own departments in the examination of river regulation,but due to the lack of understanding of other industry standards,some unnecessary scheme contradictions are often caused in the cross-industry cooperation.The study integrates and sorts out specifi cations of various departments involved in river regulation,and performs analogy study of standards of various contents in multi-industry cooperation with contents of comprehensive river regulation as the scale,so as to promote cross-industry communication of comprehensive river regulation and promote construction of integrated river regulation platform.
