Coordination Effect Enabled Palladium-Catalyzed Regioselective O-Alkylation of 2-Pyridones

A novel tactic for regioselective O-alkylation of 2-pyridones has been realized through palladium catalysis in moderate to high yields. The coordination effect between palladium and nitrogen on pyridine ring plays...

Coordination Effect and Dynamic Relationship of Green Governance and Corporate Performance

This paper uses entropy method and coupling coordination model to empirically analyze the coupling coordination effect and dynamic relationship between green governance and corporate performance of listed manufacturing companies. The results show: (1) Green governance has shown a steady growth from 2009 to 2019, but it is still in its infancy. The overall governance index is low, and there is more room for improvement. (2) The relationship between green governance and corporate performance is fluctuating in the short term, but from a long-term perspective, they have a balanced development. With the improvement of green governance, the positive effects continue to expand, bringing more obvious economic effects in the long run. (3) The degree of coupling coordination between green governance and corporate performance has fluctuated upwards, and the coordinated development has been continuously optimized. However, green governance and corporate performance have not yet reached high coupling, showing a state of primary coordination.

The coordination effect of B2B digital process capabilities on competitive performance: balancing or complementing

PurposeThe purpose of this paper is to investigate the consequences of two strategies of coordinating the online procurement capability and the online channel management capability on competitive performance.Design/methodology/approachA research model is presented to examine the performance impacts of these two coordination strategies, namely the balancing strategy (achieving a close match relationship) and the complementing strategy (maintaining the synergy effect), and tested using firm-level data collected from 196 manufacturing firms in China. Garen's two-stage econometric technique was used to identify the impacts of two coordination strategies on competitive performance.FindingsOur study discusses and compares two different coordination strategies of mitigating the operational tensions across processes and deploying resource configurations for improving competitive performance. Our results show that while the balancing strategy can mitigate the risks resulted, the complementing strategy does not create synergistic effects on the focal firms' competitive performance.Originality/valueThe results extend our understanding of the nature of B2B digital process coordination both in IS management and supply chain operations.

Switchable Structure Promoted Leaching Free Atomically Dispersed Pt Catalyst for Low Carbon Biomass Polyol Oxidation

Achieving efficient catalytic conversion over heterogeneous catalyst with excellent resistance against leaching is still a grand challenge for sustainable chemical synthesis in aqueous solution. Herein, we devised a leaching free atomically dispersed Pt1/hydroxyapatite (HAP) catalyst with unique switchable structure via a simple and green in-situ anchoring strategy. Gratifyingly, this robust Pt1/HAP catalyst exhibits remarkable catalytic selectivity and catalyst stability for the selective oxidation of C2-C4 bio-polyols (e.g., ethylene glycol, propanediol, glycerol and butanediol) to corresponding primary hydroxy acids. X-ray absorption spectroscopy, in-situ Fourier Transform infrared spectroscopy, density functional theory calculation and kinetics study elucidated that the switchable Pt-(O-P) linkages with strong electronic-withdrawing function of PO43− (Pt1-OPO43− active site) not only realize the activation of C-H bond, but also destabilize the transition state from adsorbed hydroxy acids toward the C-C cleavage, resulting in the sharply increased selectivity of hydroxy acids. Moreover, the strong PO43−-coordination effect, originating from the enhanced interaction between positively charged Pt1 and negatively charged OPO43−, provides electrostatic stabilization for the atomically dispersed Pt, ensuring the highly efficient catalysis of Pt1/HAP for over 160 hours without metal leaching. This finding opens up new opportunities for efficient upgrading of bio-polyols over atomically dispersed catalysts.

Adaptive Coordinated Motion Constraint Control for Cooperative Multi-manipulator Systems

A cooperative multi-manipulator system is a nonlinear, time-varying, strong coupling system with multiple inputs and outputs. Because of external disturbance, load change and other factors, a cooperative multi-manipulator system needs to address the problems of uncertain environment interaction, feasible control methods and coordinated planning. In this study, the coordinated motion of a multi-manipulator is divided into two types: coupling and superposition motions. An adaptive coordinated motion constraint scheme is proposed for the two different motion forms. The coupled and superposition motions were investigated by coordinating a carrying task and a circle drawing task, respectively, and the effectiveness of the adaptive coordinated motion scheme was verified. Based on the adaptive kinematics constraint algorithm of the multi-manipulator, co-simulation analysis of the multi-manipulator coordinated motion is conducted. Simulation results show that the multi-manipulator preserves the coordination relationship at all points of the trajectory planning path and has a good motion effect. Finally, an experimental platform for a cooperative multi-manipulator system was built to conduct experimental research on the coordinated motion of the multi-manipulator. Experimental results show that the proposed adaptive motion constraint control scheme for cooperative multi-manipulator systems has a good coordination effect, strong adaptivity and high-control precision.

Effective Removal of Calcium and Magnesium Ions from Water by a Novel Alginate–Citrate Composite Aerogel

In this work, a novel alginate/citrate composite aerogel (CA–SC) was synthesized by chemical grafting technology combined with vacuum freeze-drying method, and CA–SC was used for removing calcium (Ca2+) and magnesium (Mg2+) ions from water. The experimental results indicate that the as-prepared CA–SC has a high affinity for Ca2+ and Mg2+ and can remove 96.5% of Ca2+ (or 96.8% of Mg2+) from the corresponding solution. The maximum adsorption capacities of CA–SC for Ca2+ and Mg2+ are 62.38 and 36.23 mg/g, respectively. These values are higher than those of the most reported Ca2+-sorbents and Mg2+-sorbents. The CA–SC adsorbent can be regenerated through a simple pickling step, and its adsorption performance keeps stable after repeated use. Analysis of the adsorption mechanism shows that the CA–SC combines Ca2+ and Mg2+ in water mainly through coordination effect.