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A general cocatalyst strategy for performance enhancement in nickel catalyzed ethylene(co)polymerization

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Chinese Chemical Letters 2022年第9期33卷 4363-4366页

作者： Quan wang Zhao Zhang Chen Zou changle Chen CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

The tuning of olefin-polymerization catalyst properties through ligand modifications is efficient but requires complicated and costly syntheses.In this contribution,a simple Bu_(2)Mg-based cocatalyst strategy is designed that can simultaneously enhance the catalytic properties(activity,thermal stability,polymer molecular weight,branching density,melting point,etc.)of various nickel catalysts(α-diimine nickel,pyridine imine nickel and iminopyridine-N-oxide nickel)in ethylene polymerization,and enable great product morphology control.For example,a simpleα-diimine nickel catalyst can demonstrate polymerization activity of up to 1.29×10^(7)g mol^(−1)h^(−1)and molecular weight of up to 1.90×10^(6)g/mol in the presence of Bu_(2)Mg cocatalyst.The resulting polyethylenes exhibit excellent mechanical properties,with tensile stress of up to 47.4 MPa and strain of up to 1020%.This cocatalyst strategy is generally applicable to different nickel catalysts,and can lead to property enhancement in ethylene copolymerization with a series of polar comonomers such as methyl 10-undecylenate,10-undecylenic acid and 10-undecenol.

关键词： Nickel Cocatalyst Magnesium Ethylene polymerization

A“Catalyst+Support”Strategy for Salicylaldimine Nickel Catalyzed Ethylene Polymerization and Copolymerization with Polar Monomers

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Chemical Research in Chinese Universities 2023年第5期39卷 726-730页

作者： wang Zihao YANG Lei XU Mengli TAN Chen CHEN changle Key Laboratory of Precision and Intelligent Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026P.R.China Institutes of Physical Science and Information Technology Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationKey Laboratory of Environment-Friendly Polymeric Materials of Anhui ProvinceAnhui UniversityHefei 230601P.R.China School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003P.R.China

Polyolefins,as one of the most productive synthetic polymer materials,have been widely used in industry and daily life[1-2].However,due to their"non-polar"nature,polyolefins have poor compatibility and adhesion to pol... 详细信息

关键词： Nickel Salicylaldimine Polar monomer Polyolefin Heterogeneous

Plasma-enabled synthesis of ordered PtFe alloy nanoparticles encapsulated with ultrathin N-doped carbon shells for efficient methanol electrooxidation

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Nano Research 2023年第2期16卷 2065-2075页

作者： Xuxu Sun Zhijian Mao Ruiqi wang Xiaohu Pi changle Chen Junbo Zhong Qi wang Kostya(Ken)Ostrikov Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Rutgers Preparatory School New Jersey1345 Easton AveSomersetNJ 08873USA Institute of Intelligent Machines Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China College of Chemical Engineering Sichuan University of Science and EngineeringZigong 643000China School of Chemistry and Physics and QUT Centre for Materials Science Queensland University of Technology(QUT)BrisbaneQLD 4000Australia

Methanol oxidation reaction(MOR),the key reaction for clean energy generation in fuel cells,is kinetically sluggish and short-lasting because of insufficient catalytic activity and stability of the common Pt-based electrocatalysts.Ordered Pt alloy structures which promise to surmount these issues,are challenging and impractical to fabricate using common high-temperature annealing.To address the urgent need for simple and rapid synthesis methods for such alloys,here we report the versatile plasma-assisted thermal annealing synthesis of a robust electrocatalyst with PtFe alloys supported on N-doped carbon nanotubes(denoted as PtFe@NCNT-P).Benefiting from the reactive plasma-specific effects,the PtFe@NCNT-P electrocatalyst features ultrafine PtFe alloy nanoparticles(mean size~2.88 nm,ordered degree~87.07%)and ultrathin N-doped carbon(NC)shells(0.3–0.7 nm),leading to the excellent catalytic activity and stability toward MOR.The catalyst shows the specific and mass activities of 3.99 mA/cm^(2)and 2,148.5 mA/mg,which are 7.82 and 7.41 times higher than those for commercial Pt/C(0.51 mA/cm^(2),290 mA/mg),and 2.18 and 2.59 times higher compared to the plasma-untreated PtFe@NCNT(1.83 mA/cm2,829.5 mA/mg),respectively.The PtFe@NCNT-P further exhibits extraordinary stability during the long-term chronoamperometry test and 1,000-cycle cyclic voltammetry scanning,much better compared to PtFe@NCNT samples even after the longer thermal annealing.These findings show great potential of the plasma-enabled synthesis of high-performance carbon-supported metallic electrocatalysts for the emerging clean energy technologies.

关键词： methanol oxidation reaction highly ordered PtFe alloy nanoparticles ultrathin N-doped carbon shell N-doped carbon support plasma nanotechnology

A biological fluid fiber Sagnac sensor based on SPF-PCF-SPF structure

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Optoelectronics Letters 2023年第4期19卷 210-214页

作者： GUO Junqi wang changle DI Ke LI Zhehao LI Renpu LIU Yu Chongqing Key Laboratory of Autonomous Navigation and Microsystem Chongqing University of Post and TelecommunicationsChongqing 400065China Chongqing Engineering Research Center of Intelligent Sensing Technology and Microsystem Chongqing University of Posts and TelecommunicationsChongqing 400065China

A biological solution concentration sensor based on a side-polished fiber(SPF)assisted fluid system is presented.The birefringence properties of the asymmetrically filled fluid in this structure and the relationship between the concentration of the biological solution and the refractive index are theoretically analyzed.It was found that the interference peaks had red-shifted with increasing concentration.A sensing sensitivity of 1.3871×10^(4)nm·mL/mol at 14.68×10^(-4)mol/mL was achieved within the experimental range after different concentrations of arginine solutions were injected into the sensing system.This sensing system can also be applied to measure the concentration of other biological solutions,providing the feasibility of real-time detection of biological solutions.

关键词： fiber fluid structure

Baicalin inhibits inflammation of lipopolysaccharide-induced acute lung injury via toll like receptor-4/myeloid differentiation primary response 88/nuclear factor-kappa B signaling pathway

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Journal of Traditional Chinese Medicine 2022年第2期42卷 200-212页

作者： ZHU changle FENG Cuiling FENG Feng Yao Xiaoqin wang Guishu SHI Liangtian ZHENG Jiakun Department of respiration Dongzhimen Hospital Affiliated to Beijing University of Chinese MedicineBeijing 100000China Department of traditional Chinese Medicine Peking University People's HospitalBeijing100000China Department of Traditional Chinese Medicine Peking University International HospitalBeijing 100000China

OBJECTIVE:To explore the effect and mechanism of baicalin in the treatment of acute lung injury(ALI)by in vivo and in vitro experiments.METHODS:ALI was induced by instilling 10 mg/m L lipopolysaccharide(LPS)into the airway of rats.Different doses of baicalin(50 and 100 mg·kg^(-1)·d^(-1 ))were administered by gavage one day before modeling.RESULTS:Baicalin significantly reduced the permeability of the alveolocapillary membrane,alleviated tissue injury and inflammatory infiltration,and inhibited the secretion of inflammatory factors and the infiltration of neutrophils.The decline in these inflammations was related to the inhibition of the toll like receptor-4(TLR4)/myeloid differentiation factor 88(My D88)/nuclear factor-kappa B(NF-κB)/nod-like receptor pyrin containing 3(NLRP3)signaling pathway and the mitogen-activated protein kinase(MAPK)signaling pathway.CONCLUSIONS:Baicalin inhibits the secretion of inflammatory factors by inhibiting the TLR4-My D88-NF-κB/NLRP3 pathway and the MAPK signaling pathway.Thus,it reduces lung bronchial epithelial layer,alveolar damage,and pulmonary edema as detected in the in vivo and in vitro experiments.Therefore,baicalin may be a potential preventive and therapeutic drug for ALI.

关键词： baicalin acute lung injury epithelial cells lipopolysaccharides inflammation

Dual roles of trifluoroborate in nickel-catalyzed ethylene polymerization:Electronic perturbation and anchoring for heterogenization

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中国化学快报:英文版 2023年第8期34卷 352-355页

作者： Changwen Hong Zihao wang Hui Jiang Guifu Si Maoping Song changle Chen CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China College of Chemistry Zhengzhou UniversityZhengzhou 450001China

Brookhart-typeα-diimine nickel and palladium catalysts have been extensively studied over the past several decades;however,the heterogenization of these metal complexes has received much less attention.In this contribution,we installed a trifluoroborate potassium substituent on anα-diimine framework.The ionic nature of trifluoroborate potassium endowed theα-diimine nickel complex with a strong affinity for the SiO_(2)support,while its electron-donating nature enhanced the catalyst stability and polyethylene molecular weight.In the presence of only 100 equiv.of Et2AlCl cocatalyst,the SiO_(2)-supported catalyst demonstrated significantly better performance than its homogeneous analog during ethylene polymerization,with extremely high activity(1.42–6.53×10^(7)g mol^(−1)h^(−1))and high thermal stability.The heterogeneous system led to the formation of high-molecular-weight polyethylenes(Mn 142,500–732,800 g/mol),narrow polydispersities(2.18–3.00),tunable branching densities(21–64 per 1000 carbon atoms),and great mechanical properties.Moreover,the efficient copolymerization of ethylene with comonomers such as methyl 10-undecenoate,6-chloro-1-hexene or 5-hexenylacetate was achieved.These superior properties enabled by the trifluoroborate potassium moiety may inspire its applications in other polymerization catalyst systems.

关键词： Nickel catalysts Heterogeneous catalysts Olefin polymerization Polar monomer Copolymerization

Robust adaptive fault-tolerant control of a tandem coaxial ducted fan aircraft with actuator saturation

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Chinese Journal of Aeronautics 2018年第6期31卷 1298-1310页

作者： Xiaoliang wang changle XIANG Homayoun NAJJARAN Bin XU Vehicle Research Center School of Mechanical Engineering Beijing Institute of Technology Okanagan School of Engineering The University of British Columbia

This paper is concerned with the robust adaptive fault-tolerant control of a tandem coaxial ducted fan aircraft under system uncertainty, mismatched disturbance, and actuator saturation.For the proposed aircraft, comprehensive controllability analysis is performed to evaluate the controllability of each state as well as the margin to reject mismatched disturbance without any knowledge of the controller. Mismatched disturbance attenuation is ensured through a structured Hinfinity controller tuned by a non-smooth optimization algorithm. Embedded with the H-infinity controller, an adaptive control law is proposed in order to mitigate matched system uncertainty and actuator fault. Input saturation is also considered by the modified reference model. Numerical simulation of the novel ducted fan aircraft is provided to illustrate the effectiveness of the proposed method. The simulation results reveal that the proposed adaptive controller achieves better transient response and more robust performance than classic Model Reference Adaptive Control（MRAC） method, even with serious actuator saturation.

关键词： Comprehensive controllability Ducted fan aircraft Fault-tolerant Input saturation Robust adaptive control

A multi-objective power flow optimization control strategy for a power split plug-in hybrid electric vehicle using game theory

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Science China(Technological Sciences) 2021年第12期64卷 2718-2728页

作者： wang WeiDa wang WeiQi YANG Chao LIU Cheng YANG LiuQuan SUN XiaoXia XIANG changle School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Vehicle Transmission Beijing 100081China China North Vehicle Research Institute Beijing 100072China

Power flow optimization control,which governs the energy flow among engine,battery,and motor,plays a very important role in plug-in hybrid electric vehicles(PHEVs).Its performance directly affects the fuel economy of PHEVs.For the purpose of improving fuel economy,the electric system including battery and motor will be frequently scheduled,which would affect battery life.Therefore,a multi-objective optimization mechanism taking fuel economy and battery life into account is necessary,which is also a research focus in field of hybrid vehicles.Motivated by this issue,this paper proposes a multi-objective power flow optimization control strategy for a power split PHEV using game theory.Firstly,since the demand power of driver which is necessary for the power flow optimization control,cannot be known in advance,the demand power of driver can be modelled using a Markov chain to obtain predicted demand power.Secondly,based on the predicted demand power,the multi-objective optimization control problem is transformed into a game problem.A novel non-cooperative game model between engine and battery is established,and the benefit function with fuel economy and battery life as the optimization objective is proposed.Thirdly,under the premise of satisfying various constraints,the participants of the above game maximize their own benefit function to obtain the Nash equilibrium,which comprises of optimal power split scheme.Finally,the proposed strategy is verified compared with two baseline strategies,and results show that the proposed strategy can reduce equivalent fuel consumption by about 15%compared with baseline strategy 1,and achieve similar fuel economy while greatly extend battery life simultaneously compared with baseline strategy 2.

关键词： power split PHEV power flow optimization control multi-objective game theory battery life

Interplay of Supramolecular Chemistry and Photochemistry with Palladium-Catalyzed Ethylene Polymerization

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CCS Chemistry 2021年第7期3卷 2025-2034页

作者： Guohong wang Dan Peng Yao Sun changle Chen CAS Key Laboratory of Soft Matter Chemistry Hefei National Laboratory for Physical Sciences at the MicroscaleDepartment of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026

Metal–metal cooperativity effects have been extensively explored in olefin polymerization,along with the design and preparation of many binuclear transition metal catalysts.However,their synthesis and the tuning of metal–metal distance are complicated and time-consuming.In this contribution,a supramolecular chemistry strategy was used to construct multinuclear olefin polymerization catalysts.Urea functional groups were installed into severalα-diimine palladium catalysts to enable hydrogenbonding-induced self-assembly.

关键词： ethylene polymerization polyolefin supramolecular chemistry photochemistry palladium