A novel purification process based on mixer-settlers for high-purity NdClwas developed. Acidic solution and pure NdClsolution were compared to scrub the less-extractable rare earths(REs)(La, Ce, and Pr)from loaded org...A novel purification process based on mixer-settlers for high-purity NdClwas developed. Acidic solution and pure NdClsolution were compared to scrub the less-extractable rare earths(REs)(La, Ce, and Pr)from loaded organic phase. The extractant with low-degree saponification was evaluated to remove the more-extractable element(Sm). Then the RE impurities(La, Ce, Pr, and Sm) in Nd were purified by an integrated process. Furthermore, effect of smuggling behavior on the purification of NdClin mixersettlers was studied. Based on the investigation mentioned above, the pilot-scale purification process for NdClwith a purity of 99.999% was developed, and the total recovery was about 99%.展开更多
1 Introduction Today’s world has become volatile,uncertain,complex,and ambiguous(VUCA).In such a world,supply chains not only are embedded in VUCA environments but also increasingly exhibit VUCA features.A widely rec...1 Introduction Today’s world has become volatile,uncertain,complex,and ambiguous(VUCA).In such a world,supply chains not only are embedded in VUCA environments but also increasingly exhibit VUCA features.A widely recognized description of the characteristics of VUCA was developed by Bennett and Lemoine(2014),outlined in the following.Volatility:An event encountered by a supply chain is unexpected or unstable;however,information on such an event is available and its impact is generally predictable.Uncertainty:The cause and effect of an event encountered by a supply chain are known;however,other information about the event is unavailable.Complexity:Both the environment and the supply chain itself have many interconnected parts and variables;hence,connecting the cause and effect of an event is very difficult.Ambiguity:An event encountered by a supply chain is unexpected.展开更多
Governments at all levels are increasingly motivating the private sector to participate in infrastructure development using alternative project delivery methods to relieve financial burden. When designing contracts, g...Governments at all levels are increasingly motivating the private sector to participate in infrastructure development using alternative project delivery methods to relieve financial burden. When designing contracts, governments usually offer incentives while requiring cost or time guarantee to balance project attractiveness to the private sector and fair protection of public interest. However, a practical and critical problem is how to properly design these provisions. Although previous studies have investigated the value of these provisions, a knowledge gap still exists with respect to methods of fairly and effectively designing such provisions. This study fills this gap by developing a methodology that analyzes the appropriateness of guarantee or warranty provisions for contracts. In this study, a contract reliability index is constructed, and a process of evaluating contract reliability is proposed. The New Mexico Highway 44 project, in which three warranty provision arrangements are investigated, is used as a case study to illustrate the analysis process. Results show that although a ceiling clause can effectively motivate the private sector to participate in the project, it sacrifices a significant amount of public benefits. By contrast, although a warranty option can protect public benefits, it cannot effectively incentivize the private sector. A combination of the ceiling clause and the warranty option will therefore result in improved contract provision design. The proposed methodology in this study is especially useful for governments in properly determining contract clauses in infrastructure development.展开更多
基金Project supported by'Hundreds Talents Program' from Chinese Academy of Sciences,Science and Technology Major Project of Fujian Province(2015HZ0001-3)National Natural Science Foundation of China(21571179)Science and Technology Major Project of Ganzhou(2017-8)
文摘A novel purification process based on mixer-settlers for high-purity NdClwas developed. Acidic solution and pure NdClsolution were compared to scrub the less-extractable rare earths(REs)(La, Ce, and Pr)from loaded organic phase. The extractant with low-degree saponification was evaluated to remove the more-extractable element(Sm). Then the RE impurities(La, Ce, Pr, and Sm) in Nd were purified by an integrated process. Furthermore, effect of smuggling behavior on the purification of NdClin mixersettlers was studied. Based on the investigation mentioned above, the pilot-scale purification process for NdClwith a purity of 99.999% was developed, and the total recovery was about 99%.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.72031008,71901161,and 71702020).
文摘1 Introduction Today’s world has become volatile,uncertain,complex,and ambiguous(VUCA).In such a world,supply chains not only are embedded in VUCA environments but also increasingly exhibit VUCA features.A widely recognized description of the characteristics of VUCA was developed by Bennett and Lemoine(2014),outlined in the following.Volatility:An event encountered by a supply chain is unexpected or unstable;however,information on such an event is available and its impact is generally predictable.Uncertainty:The cause and effect of an event encountered by a supply chain are known;however,other information about the event is unavailable.Complexity:Both the environment and the supply chain itself have many interconnected parts and variables;hence,connecting the cause and effect of an event is very difficult.Ambiguity:An event encountered by a supply chain is unexpected.
文摘Governments at all levels are increasingly motivating the private sector to participate in infrastructure development using alternative project delivery methods to relieve financial burden. When designing contracts, governments usually offer incentives while requiring cost or time guarantee to balance project attractiveness to the private sector and fair protection of public interest. However, a practical and critical problem is how to properly design these provisions. Although previous studies have investigated the value of these provisions, a knowledge gap still exists with respect to methods of fairly and effectively designing such provisions. This study fills this gap by developing a methodology that analyzes the appropriateness of guarantee or warranty provisions for contracts. In this study, a contract reliability index is constructed, and a process of evaluating contract reliability is proposed. The New Mexico Highway 44 project, in which three warranty provision arrangements are investigated, is used as a case study to illustrate the analysis process. Results show that although a ceiling clause can effectively motivate the private sector to participate in the project, it sacrifices a significant amount of public benefits. By contrast, although a warranty option can protect public benefits, it cannot effectively incentivize the private sector. A combination of the ceiling clause and the warranty option will therefore result in improved contract provision design. The proposed methodology in this study is especially useful for governments in properly determining contract clauses in infrastructure development.
