IR STUDIES ON SURFACE CHEMISTRY OF RHODIUM IN HYDROFORMYLATION CATALYSTS

lntroductionRhodiummctalandrh0dlumcompoundsarcvery'extcnsivclystudiedandappllcdlnthcfieldofhctcrogcncousClcatalysis,bccauseofthcirmultifuncti0naIactivationtowardC0andhighcatal}ticactivityRegardingthenatureofintcractionofrhodiumwiththcsuffocesofoxidesandC0,manyinvcstigatorshavedescribcdtheiravailableexperimcntalresultsonthebasis0fspcctroscopicobscrvationsAInbiguityanddebateexist,concerningtheformationofsurfaccffo (C0)2BascdonIRstudieswithRh/Al2O3,earlierinvcstlgatorshavcprop0scdrcspcctivcl}…     

选拔赛规则“40进16”的合理性证明和推广

论证了"40进16"选拔赛规则的合理性,将"40进16"选拔赛规则推广到了"一般形式",使之成为适于大型赛事的晋级规则.提出了该项晋级规则施用于大型选拔赛全赛程的积极意义."一般形式"的比赛规则对今后赛事规则的制定具有重要参考价值.     

An Exploration of Seaweed Polysaccharides Stimulating Denitrifying Bacteria for Safer Nitrate Removal

Excessive use of nitrogen fertilizer in intensively managed agriculture has resulted in abundant accumulation of nitrate in soil, which limits agriculture sustainability. How to reduce nitrate content is the key to alleviate secondary soil salinization. However, the microorganisms used in soil remediation cause some problems such as weak efficiency and short survival time. In this study, seaweed polysaccharides were used as stimulant to promote the rapid growth and safer nitrate removal of denitrifying bacteria. Firstly, the growth rate and NO₃⁻-N removal capacity of three kinds of denitrifying bacteria, Bacillus subtilis (BS), Pseudomonas stutzeri (PS) and Pseudomonas putida (PP), were compared. The results showed that Bacillus subtilis (BS) had a faster growth rate and stronger nitrate removal ability. We then studied the effects of Enteromorpha linza polysaccharides (EP), carrageenan (CA), and sodium alginate (AL) on growth and denitrification performance of Bacillus subtilis (BS). The results showed that seaweed polysaccharides obviously promoted the growth of Bacillus subtilis (BS), and accelerated the reduction of NO₃⁻-N. More importantly, the increased NH₄⁺-N content could avoid excessive loss of nitrogen, and less NO₂⁻-N accumulation could avoid toxic effects on plants. This new strategy of using denitrifying bacteria for safely remediating secondary soil salinization has a great significance.     

化学青年教师实验素养的问题表现与提升路径—基于 2020年江苏省高中化学青年教师教学基本功大赛

江苏省高中化学青年教师教学基本功大赛突出了对教师实验素养的考查。大赛中对教师实验素养考查的内容有6个项目。通过观摩大赛,发现部分选手实验素养较弱,表现在化学实验安全知识“口是心非”,化学基础原理知识“似是而非”,化学实验内容设计未能体现“以生为本”,化学实验操作未能“精益求精”。分析青年教师实验素养问题的原因,提出青年教师实验素养提升的路径有:落实教师实验素养提升培训活动,开展实验创新研讨活动,突出基于实验内容的教学设计。     

Promotion Systems and Organizational Performance: A Contingency Model

This study explores the organizational impact of a variety of important promotion systems commonly practiced in organizations including up-or-out systems, absolute merit-based systems, relative merit-based systems, and seniority-based systems. Through the computer simulation of organizations in a distributed decision making setting, the results indicate that the effectiveness of any promotion system is dependent on a range of factors including the nature of the task environment, the design of the organizational structure, the frequency of monitoring, the criteria of performance, and the transferability of task knowledge. This study has implications not only for understanding organizational promotion systems from the contingency perspective, but also for bridging the fields of strategic human resource management and computational organization theory.     

Review and Perspectives of the Use of Alginate as a Polymer Matrix for Microorganisms Applied in Agro-Industry

Alginate is a polysaccharide with the property of forming hydrogels, which is economic production, zero toxicity, and biocompatibility. In the agro-industry, alginate is used as a super absorbent polymer, coating seeds, fruits, and vegetables and as a carrier of bacteria and fungi as plant-growth promoters and biocontrol. The latter has a high impact on agriculture since the implementation of microorganisms in a polymer matrix improves soil quality; plant nutrition, and is functional as a preventive measure for the appearance of phytopathogenic. Additionally, it minimizes losses of foods due to wrong post-harvest handling. In this review, we provide an overview of physicochemical properties of alginate, some methods for preparation and modification of capsules and coatings, to finally describe its application in agro-industry as a matrix of plant-growth-promoting microorganisms, its effectiveness in cultivation and post-harvest, and its effect on the environment, as well as the prospects for future agro-industrial applications.     

Behavior Variations and Their Implications for Popularity Promotions: From Elites to Mass on Weibo

The boom in social media with regard to producing and consuming information simultaneously implies the crucial role of online user influence in determining content popularity. In particular, understanding behavior variations between the influential elites and the mass grassroots is an important issue in communication. However, how their behavior varies across user categories and content domains and how these differences influence content popularity are rarely addressed. From a novel view of seven content domains, a detailed picture of the behavior variations among five user groups, from the views of both the elites and mass, is drawn on Weibo, one of the most popular Twitter-like services in China. Interestingly, elites post more diverse content with video links, while the mass possess retweeters of higher loyalty. According to these variations, user-oriented actions for enhancing content popularity are discussed and testified. The most surprising finding is that the diverse content does not always bring more retweets, and the mass and elites should promote content popularity by increasing their retweeter counts and loyalty, respectively. For the first time, our results demonstrate the possibility of highly individualized strategies of popularity promotions in social media, instead of a universal principle.     

配体促进的过渡金属催化芳烃远程meta-C—H键官能化反应研究进展

过渡金属催化C—H活化反应中,配体能够对催化中心的空间及电子效应进行调控,从而实现芳烃C—H键的选择性官能化.近年来,配体促进芳烃远程C—H键官能化反应研究有了新的进展.对近几年来配体促进的过渡金属催化芳烃远程meta-C—H键选择性官能化反应进行了系统总结,并对该研究领域的局限性和未来的发展前景进行总结和展望.     

Highly Active Catalysis of Cobalt Tetrakis(pentafluorophenyl)porphyrin Promoted by Chitosan for Cyclohexane Oxidation in Response-Surface-Methodology-Optimized Reaction Conditions

We aimed at elevating catalytic performances of cobalt tetrakis(pentafluorophenyl)porphyrin (Co TPFPP) through axial coordination, nanocavities, and covalently grafting action. The Co TPFPP was immobilized onto nanoporous and nonporous chitosan, forming Co TPFPP/np- and nonp-CTS catalysts, respectively. The catalysts were characterized by various spectroscopic techniques. The catalytic performances of these catalysts for cyclohexane oxidation under response-surface-methodology-optimized oxidation reaction conditions were estimated and compared. Co TPFPP/np-CTS was an excellent catalyst at aspect of catalytic activity, exhibiting the considerable potential reusability, 24.2 mol % yields (KA oil : cyclohexanone and cyclohexanol) in average, and total turnover frequencies (TOFs) of 3.25×10⁶ h⁻¹. This is attributed to the structural characteristics of the Co TPFPP/np-CTS catalyst: the cobalt porphyrin molecules could be highly scattered on CTS, forming the independent active sites, and were not leached. The axial coordination exerted the most important effect on the catalytic activity, and the covalent grafting action had a decisive effect on the increase of the total TOFs and on the reusability of the catalyst.     

供应链协同视角的联合促销演化博弈分析

制造商和零售商联合促销产生协同效应影响供应链成员的策略选择.利用演化博弈模型研究了制造商和零售商联合促销互动进程中的演化路径,并仿真了初始意愿、协同效应、促销补助等参数对演化系统的影响.研究表明:协同效应高于一定值才能形成制造商和零售商稳定的联合促销;如果制造商对零售商的处罚收入小于促销投入且零售商促销额外收益不能弥补...