Farmers are both the producers and consumers of food, and as such have a dual role in food safety： they both generate risks and are exposed to them. Based upon a survey of the food production and consumption habits o...Farmers are both the producers and consumers of food, and as such have a dual role in food safety： they both generate risks and are exposed to them. Based upon a survey of the food production and consumption habits of 140 farm households and long-term research in two villages in Yunnan province, this study found that rural families are highly dependent on the market for food production and consumption. In their role as consumers, farmers are aware of food safety risks and concerned about them, but their ability to protect themselves is limited. They do so primarily by avoiding certain products and growing as much of their own food as possible. At the same time, in their role as producers, farmers engage in practices, primarily the overuse and inappropriate use of fertilizer and pesticides, that are damaging to food safety and the environment. There is therefore a disconnect in their roles as consumers and producers that needs to be addressed if policy goals for improving food safety and reducing the use of agricultural chemicals are to be achieved. Farmers need more information about food safety risks related to the products they consume themselves, and technical guidance on the safe use of farm chemicals when growing food for market. However, such measures will not be effective unless the external pressures on farmers are also addressed, through consideration of market incentives to use farm chemicals and the impact of consumer demand.展开更多
Herein we summarized some clean preparation examples to emphasize the concept of dual roles design(or named as "two birds one stone strategy") in green and sustainable chemistry.In those examples,the reactan...Herein we summarized some clean preparation examples to emphasize the concept of dual roles design(or named as "two birds one stone strategy") in green and sustainable chemistry.In those examples,the reactants and/or solvent play dual roles rendering a cleaner organic preparation process.Consequently,both the chemical waste and manufacturing cost could be reduced.展开更多
Traditional data envelopment analysis（DEA） theory assumes that decision variables are regarded as inputs or outputs,and no variable can play the roles of both an input and an output at the same time.In fact,there ex...Traditional data envelopment analysis（DEA） theory assumes that decision variables are regarded as inputs or outputs,and no variable can play the roles of both an input and an output at the same time.In fact,there exist some variables that work as inputs and outputs simultaneously and are called dual-role variables.Traditional DEA models cannot be used to appraise the performance of decision making units containing dual-role variables.The paper analyzes the structure and properties of the production systems comprising dual-role variables,and proposes a DEA model integrating dual-role variables.Finally the proposed model is illustrated to evaluate the efficiency of university departments.展开更多
本文选用 1998 年以前上市的所有 A 股公司作为样本,对样本公司的股权特征与董事会领导结构之间的关系进行了研究。研究结果表明:(1)董事长和总经理两职合一模式的公司比例在逐年下降;(2)含有国家股和国家股比例越高的公司越倾向于总经...本文选用 1998 年以前上市的所有 A 股公司作为样本,对样本公司的股权特征与董事会领导结构之间的关系进行了研究。研究结果表明:(1)董事长和总经理两职合一模式的公司比例在逐年下降;(2)含有国家股和国家股比例越高的公司越倾向于总经理和董事长两个职位由同一个人担任;(3)由母公司控股以及中央和部委所属的公司更倾向于由大股东董事长同时担任上市公司董事长;(4)控股股东持股比例越高,控股股东董事长担任上市公司董事长的可能性就越大。展开更多
基金FORHEAD with funding from the Rockefeller Brothers Fund(RBF)
文摘Farmers are both the producers and consumers of food, and as such have a dual role in food safety： they both generate risks and are exposed to them. Based upon a survey of the food production and consumption habits of 140 farm households and long-term research in two villages in Yunnan province, this study found that rural families are highly dependent on the market for food production and consumption. In their role as consumers, farmers are aware of food safety risks and concerned about them, but their ability to protect themselves is limited. They do so primarily by avoiding certain products and growing as much of their own food as possible. At the same time, in their role as producers, farmers engage in practices, primarily the overuse and inappropriate use of fertilizer and pesticides, that are damaging to food safety and the environment. There is therefore a disconnect in their roles as consumers and producers that needs to be addressed if policy goals for improving food safety and reducing the use of agricultural chemicals are to be achieved. Farmers need more information about food safety risks related to the products they consume themselves, and technical guidance on the safe use of farm chemicals when growing food for market. However, such measures will not be effective unless the external pressures on farmers are also addressed, through consideration of market incentives to use farm chemicals and the impact of consumer demand.
基金financial support from the National Natural Science Foundation of China(Nos.21545010 and 31527803)Hunan Provincial Natural Science Foundation of China(No. 2019JJ20008)
文摘Herein we summarized some clean preparation examples to emphasize the concept of dual roles design(or named as "two birds one stone strategy") in green and sustainable chemistry.In those examples,the reactants and/or solvent play dual roles rendering a cleaner organic preparation process.Consequently,both the chemical waste and manufacturing cost could be reduced.
基金supported by the National Natural Science Foundation of China (7082100170801056)
文摘Traditional data envelopment analysis（DEA） theory assumes that decision variables are regarded as inputs or outputs,and no variable can play the roles of both an input and an output at the same time.In fact,there exist some variables that work as inputs and outputs simultaneously and are called dual-role variables.Traditional DEA models cannot be used to appraise the performance of decision making units containing dual-role variables.The paper analyzes the structure and properties of the production systems comprising dual-role variables,and proposes a DEA model integrating dual-role variables.Finally the proposed model is illustrated to evaluate the efficiency of university departments.
文摘本文选用 1998 年以前上市的所有 A 股公司作为样本,对样本公司的股权特征与董事会领导结构之间的关系进行了研究。研究结果表明:(1)董事长和总经理两职合一模式的公司比例在逐年下降;(2)含有国家股和国家股比例越高的公司越倾向于总经理和董事长两个职位由同一个人担任;(3)由母公司控股以及中央和部委所属的公司更倾向于由大股东董事长同时担任上市公司董事长;(4)控股股东持股比例越高,控股股东董事长担任上市公司董事长的可能性就越大。
