Iron‐catalyzed carbon–sulfur bond formation: Atom‐economic construction of thioethers with diaryliodonium salts

Diaryliodonium salts are characterized by poor atom economy with the formation of one equivalent of an iodoarene as waste. We have developed an atom‐economic iron‐catalyzed protocol for the synthesis of a variety of thioethers with diaryliodonium salts. Not only cyclic diaryliodonium salts but also linear diaryliodonium salts were found to perform well in the reactions.     

海洋科技投入与海洋经济增长:中国沿海地区面板数据实证研究

开发海洋资源、发展海洋经济对于拓展国民经济和社会发展空间、加快转变经济发展方式、全面建设小康社会具有重大战略意义.加大海洋科技投入,促进海洋科技进步和创新是加快转变海洋经济发展方式的重要举措.根据海洋经济双对数生产函数模型,对我国11个沿海地区2001-2011年海洋经济面板数据的计量分析表明:海洋资本、海洋科技和海洋劳动的弹性系数均为正数;当3个要素投入每增长1个标准差,将引致海洋产出平均增长1.0412、0.1633、0.6837个标准差;海洋资本对海洋经济增长的贡献度最大,而海洋科技的经济增长贡献度最小,我国沿海地区海洋经济增长仍然表现为资本、劳动双要素投入驱动型.从优化主要海洋产业比重、调整海洋经济要素投入构成、提高海洋科技成果转化效益、发挥海洋科技人才主体作用等4个方面提出加快发展海洋经济的对策和措施.     

厂商低碳产品管理决策行为分析

在发展低碳经济的时代背景下,企业将面临低碳产品的管制,为符合低碳产品标准,企业将增加低碳产品的投资,对其生产工艺、技术或产品性能进行改造,势必增加企业经营成本,冲击产业发展.本文主要建立一个代表性厂商面临碳管制时低碳产品管理决策模型,期望通过厂商行为分析,掌握影响厂商低碳产品管理决策行为的关键因子,提供政府管理与厂商经营策略的参考意见.     

“Beyond an acronym,STEM is…”: Perceptions of STEM

Although STEM is at the forefront of many educational initiatives, little is known about various professionals’ perceptions of STEM. This mixed‐methods study surveyed 164 preservice teachers, inservice teachers, administrators, informal educators, and STEM professionals. Quantitative and qualitative questions on the survey elicited participants’ perceptions of STEM, STEM support, and STEM careers. Quantitative analysis revealed that profession influenced understandings of STEM, importance of STEM, support for STEM, and perceptions of STEM career opportunities. Qualitative analysis provided rich explanations for the differences in perceptions among professions. This study suggests that science teacher educators need to ensure preservice teachers have understandings of STEM and STEM careers, K‐16 educators need to emphasize the current importance of STEM, and administrators and policymakers need to align visions of STEM with curriculum and pacing guides so teachers feel supported in their STEM endeavors.     

城市轨道交通运营规模与经济发展的耦合协调性分析

城市轨道交通运营规模与经济协调发展是城市轨道交通健康发展的基础.为研究城市轨道交通运营规模与经济发展的耦合协调性,采用了物理学的耦合模型对2007-2019年城市轨道交通和经济发展数据进行了实证分析,对城市轨道交通运营规模和经济发展的综合水平、耦合度、耦合协调度进行了测算.研究表明:城市轨道交通运营规模和经济发展综合水平持续上升,城市轨道交通运营规模滞后于经济发展水平;城市轨道交通运营规模与经济发展两者具有较高的耦合度;城市轨道交通运营规模—经济发展耦合协调度是逐年提高的,2016年以后城市轨道交通运营规模和经济发展进入一个较好互动影响阶段.     

Hydrogen energy currency: Beyond state-of-the-art transition metal oxides for oxygen electrocatalysis

In this opinion piece, we highlight and discuss beyond state-of-the-art transition metal oxide materials for the oxygen evolution reaction and oxygen reduction reaction, which are essential for the renewable energy conversion and storage of H₂ to electricity. We pinpoint some of the synthetic routes taken and discuss essential measurements required in the highlighted works, which others should undertake to achieve highly active and stable oxygen evolution reaction and oxygen reduction reaction catalysts in both acidic and alkaline media.     

Direct Metal‐Catalyzed Regioselective Functionalization of Enamides

Enamides are stable enamine surrogates and provide key intermediates for the synthesis of small but complex nitrogen‐containing compounds. Metal‐catalyzed regioselective functionalization of enamides provides a rapid method to synthesize useful nitrogen containing heterocycles. This review discloses the recent progress made in the development of the C?H functionalization of enamides involving efficient and atom‐economical routes. Syntheses of different heterocycles are classified based on the site reactivity of enamides and key mechanistic insights are given for each transformation.     

Suspension Fertilizers Based on Waste Phosphates from the Production of Polyols

Phosphorus raw materials are non-renewable, and their resources are shrinking faster and faster as a result of increased fertilizer production. This is due to the increasing population and the need to produce more food. Phosphorus, on the other hand, is one of the main nutrients of plants, without which it is impossible to conduct intensive agricultural production. There are no economically significant phosphate resources in Europe, so they must be imported. That is why it is so important to reduce losses and recover this element from waste streams, which was reflected in the new EU Regulation 2019/1009. A prospective option is to use waste phosphates from the production of polyether polyols. Previous studies show that they contain about 20% phosphorus. Due to their high water content, the most advantageous form of their application is the production of fertilizers in the form of a suspension. The aim of the study is to assess the possibility of using waste phosphates from the production of polyols as raw materials for the production of suspension fertilizers.     

从开放资源到基础服务：平台监管的新视角

数字经济研究者往往忽视了推动生产要素背后的力量,即那些汇集众人之力产生大量交易和相关数据,通过智能算法进行分析,使生产/交易更加自动化和高效的力量,这种力量来自不断演进生成的“平台”。有必要探讨（特别是中国语境下）互联网平台的一般性理论,将资源、数据、算法和基础服务视为构成平台经济的核心要素,希望加深对平台经济的理解。除了传统上讨论较多的资源、数据、算法外,应将平台基础服务放在重要位置,这是推动创新的引擎,也是影响互联网治理规则和监管的重要要素。监管的目标是使整个经济具有活力,不仅涉及为市场主体减轻负担,还包括在平台之间推动资源的有序自由流动。因此,未来互联网监管政策的重点应放在推动资源有序流动和增强平台基础服务能力上面。