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Applications of in-situ solid-state nuclear magnetic resonance in methanol to olefins reaction

Science China Chemistry 2025年第1期68卷 134-151页

作者： Jing Niu Shutao Xu Yingxu Wei Zhongmin Liu national engineering research center of Lower-Carbon catalysis Technology Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China State Key Laboratory of catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

The methanol-to-olefins(MTO)reaction offers an alternative pathway for the production of low-carbon olefins from non-oil *** research has been impeded by a lack of comprehensive understanding of its underlying mechanism,despite the significant progress made in ***-situ solid-state nuclear magnetic resonance(ss NMR)spectroscopy has emerged as a pivotal tool,offering crucial insights into key species under real-time operando ***,the host–guest interaction between zeolites or surface species residing on zeolites and the reactant/active intermediates is revealed by the combination of in-situ^(13)C MAS NMR and 2D correlation ***,recent technological advancements in hyperpolarization(HP)methods,including HP^(129)Xe NMR and dynamic nuclear polarization(DNP),have significantly improved the sensitivity of ssNMR,enabling detailed structural and kinetic analysis as well as the detection of trace *** this feature article,we summarized recent advancements in(in-situ)ssNMR spectroscopy applied to MTO reaction processes,encompassing mechanistic investigations at various stages and the intricate host–guest *** theoretical insights into the dynamic evolution of MTO reactions lay a solid foundation for the optimization of catalytic processes and the development of efficient catalysts,thereby advancing the techniques towards more sustainable and economical production route for olefins.

关键词： MTO zeolites in-situ ssNMR reactive intermediates reaction mechanism

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Ce-doped TiO_(2)supported RuO_(2)as efficient catalysts for the oxidation of HCl to Cl_(2)

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Journal of Environmental Sciences 2025年第3期149卷 234-241页

作者： Jiahui Liu Fangyuan Dong Yaqi Huang Yanghe Fu Xinqing Lu Rui Ma Fumin Zhang Shuhua Wang Weidong Zhu Key Laboratory of the Ministry of Education for Advanced catalysis Materials Zhejiang Engineering Laboratory for Green Syntheses and Applications of Fluorine-Containing Specialty ChemicalsZhejiang Normal UniversityJinhua 321004China national engineering Technology research center of Fluoro-Materials Zhejiang Juhua Technology Center Co.Ltd.Quzhou 324004China

Reducing the cost of RuO_(2)/TiO_(2)catalysts is still one of the urgent challenges in catalytic HCl *** the present work,a Ce-doped TiO_(2)supported RuO_(2)catalyst with a low Ru loading was developed,showing a high activity in the catalytic oxidation of HCl to Cl_(2).The results on some extensive characterizations of both Ce-doped TiO_(2)carriers and their supported RuO_(2)catalysts show that the doping of Ce into TiO_(2)can effectively change the lattice parameters of TiO_(2)to improve the dispersion of the active RuO_(2)species on the carrier,which facilitates the production of surface Ru species to expose more active sites for boosting the catalytic performance even under some harsh reaction *** work provides some scientific basis and technical support for chlorine recycling.

关键词： Deacon reaction RuO_(2)/TiO_(2) chlorine recycling HCl oxidation Ce doping

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A review of over-discharge protection through prelithiation in working lithium-ion batteries

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Journal of Energy Chemistry 2025年第2期101卷 437-452页

作者： Hanchen Wang Yingtian Liu Mingze Jiang Qiang Zhang School of Aerospace engineering National Engineering Research Center of Neuromodulation Tsinghua University Tsinghua center for Green Chemical engineering Electrification Department of Chemical Engineering Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Tsinghua University

The demand for high safety and high reliability lithium-ion batteries(LIBs) is strongly considered for practical ***,due to their inherent self-discharge properties or abuse,LIBs face the threat of over-discharge,which induces premature end of life and increased risk of thermal *** addition,a strong demand for batteries with zero-volt storage is strongly considered for aerospace and implantable medical *** this review,we firstly introduce the necessity and the importance of over-discharge and zero-volt protection for *** mechanism of damage to the Cu current collectors and SEI induced by potential changes during over-discharge is *** current over-discharge protection strategies based on whether the zero-crossing potential of the electrodes is ***,the fresh insights into the material design of cathode prelithiation additives are presented from the perspective of over-discharge protection.

关键词： Electrode potential regulation Electrode prelithiation Li-ion batteries Over-discharge protection Zero-volt storage

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Oscillatory flow reactor facilitates fast photochemical Wolff rearrangement toward synthesis of α-substituted amides in flow

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Chinese Chemical Letters 2025年第2期36卷 389-393页

作者： Huashan Huang Jingze Chen Luyun Zhang Hong Yan Siqi Li Fen-Er Chen Institute of Pharmaceutical Science and Technology College of Chemistry Fuzhou University Key Laboratory of Natural Medicines of the Changbai Mountain Ministry of Education Molecular Medicine Research Center College of Pharmacy Yanbian University engineering center of catalysis and Synthesis for Chiral Molecules Department of Chemistry Fudan University Shanghai engineering center of Industrial catalysis for Chiral Drugs

A visible light-promoted fast photochemical Wolff rearrangement was developed toward synthesis of α-substituted amides in continuous flow with the use of a photochemical oscillatory flow reactor(POFR).The control experiment indicates that a fast process of the Wolff rearrangement(<40 s) is involved. Notably, this protocol does not require excess use of any reactants, and the resulting α-substituted amides could be isolated by recrystallization in good to excellent yields.

关键词： Flow photochemistry Ketene Oscillatory flow reactor Wolff rearrangement α-Substituted amides

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Secure beamforming and deployment design for rate-splitting multiple access-based UAV communications

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Science China(Information Sciences) 2025年第1期68卷 342-356页

作者： Bing WANG Xiaofeng TAO Shujun HAN Huici WU Kai YANG Zhu HAN national engineering research center of Mobile Network Technologies Beijing University of Posts and Telecommunications Peng Cheng Laboratory Department of Electrical and Computer engineering University of Houston

Rate-splitting multiple access(RSMA) has recently gained attention as a potential robust multiple access(MA)scheme for upcoming wireless networks. Given its ability to efficiently utilize wireless resources and design interference management strategies, it can be applied to unmanned aerial vehicle(UAV) networks to provide convenient services for large-scale access ground users. However, due to the line-of-sight(LoS) broadcast nature of UAV transmission, information is susceptible to eavesdropping in RSMA-based UAV networks. Moreover, the superposition of signals at the receiver in such networks becomes complicated. To cope with the challenge, we propose a two-user multi-input single-output(MISO) RSMA-based UAV secure transmission framework in downlink communication networks. In a passive eavesdropping scenario, our goal is to maximize the sum secrecy rate by optimizing the transmit beamforming and deployment location of the UAV-base station(UAV-BS),while considering quality-of-service(QoS) constraints, maximum transmit power, and flight space limitations. To address the non-convexity of the proposed problem, the optimization problem is first decoupled into two subproblems. Then, the successive convex approximation(SCA) method is employed to solve each subproblem using different propositions. In addition, an alternating optimization(AO)-based location RSMA(L-RSMA) beamforming algorithm is developed to implement joint optimization to obtain the suboptimal solution. Numerical results demonstrate that(1) the proposed L-RSMA scheme yields a28.97% higher sum secrecy rate than the baseline L-space division multiple access(SDMA) scheme;(2) the proposed L-RSMA scheme improves the security performance by 42.61% compared to the L-non-orthogonal multiple access(NOMA) scheme.

关键词： rate-splitting multiple access UAV communication precoding optimization deployment location physical layer security

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Green innovation unleashed: Harnessing tungsten-based nanomaterials for catalyzing solar-driven carbon dioxide conversion

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Chinese Chemical Letters 2025年第2期36卷 136-145页

作者： Weidan Meng Yanbo Zhou Yi Zhou State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process East China University of Science and Technology national engineering research center of Industrial Wastewater Detoxication and Resource Recovery East China University of Science and Technology Shanghai Institute of Pollution Control and Ecological Security Shanghai engineering research center for Multi-media Environmental catalysis and Resource Utilization East China University of Science and Technology

Carbon dioxide photocatalytic reduction (CO2-PR) is an efficient method for controlling CO2emissions and generating cleaner energy while mitigating global warming. Tungsten oxides (WxOy) have attracted considerable attention for CO2-PR due to their excellent spectral absorbance. However, comprehensive reviews are lacking on the use of WxOyfor CO2-PR. Therefore, this review provides a detailed summary of t research progress made with WxOy-based catalysts in CO2-PR. It also explains the fundamental principles of CO2-PR and evaluates key performance indicators that affect the activity of WxOy-based photocatalysts,including yield, selectivity, stability, and apparent quantum yield. Additionally, this review explores opportunities for synthesizing high-performance WxOy-based photocatalysts and highlights their potential for the green preparation of C1/C2 products through CO2-PR. These innovative strategies aim to address the challenges and pressures associated with energy and environmental issues, particularly by enhancing artificial photosynthesis efficiency.

关键词： Carbon dioxide photoreduction Mechanism Performance evaluation Selectivity Tungsten-based nanocatalyst

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Subsection cooling system of hot rolling silicon steel and its industrial application

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Journal of Iron and Steel research International 2025年第1期32卷 159-170页

作者： Qiu-na Wang Ji-quan Sun Li-po Yang Hai-shen Wang Li-jie Dong Jie-ming Li Zhen-yang Zhi Yan-wen Bi national engineering research center of Flat Rolling Equipment University of Science and Technology BeijingBeijing100083China Hot Rolling Department of Qian’an Iron and Steel Corporation Shougang Company LimitedTangshan064404HebeiChina national engineering research center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina

An online subsection cooling method for hot rolling silicon steel was designed to achieve local adjustment of transverse roll ***,it was able to meet the requirements of edge drop of the strip by using the features of online thermal ***,after the new subsection spray beam was installed at the exit of mill,the special local cooling rules were analyzed for altering the thermal crown of roll according to rolling process ***,the dynamic impact of subsection cooling on the local thermal crown could just be obtained according to the measured ***,the heat transfer coefficient was determined by different subsection cooling curves under varied rolling ***,the rolling rhythm and variable conditions were important dynamic factors of transient roll temperature in practical rolling ***,real-time calculation and presetting of the thermal crown were carried out to maximize special requirements of load roll gap on local strip *** this new method,the transient temperature and the thermal crown of roll could be quantitatively controlled *** the practical results showed that the predicted temperature was able to match the measured value by more than 95%.Meanwhile,the adjustable range of thermal crown increased by more than 2.5 ***,the qualification rate of strip edge crown has increased from the original 30%to over 70%.

关键词： Subsection cooling Thermal roll crown Multi-parameter coupling Hot rolling Silicon steel

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Substrate bias effects in p-channel GaN-on-Si transistors

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Science China(Information Sciences) 2025年第1期68卷 404-405页

作者： Mengyao ZHAO Jie MA Lanlan YANG Chuanqi PAN Denggui WANG Jianjun ZHOU Sheng LI Jiaxing WEI Long ZHANG Siyang LIU Weifeng SUN national ASIC System engineering research center School of Integrated Circuits Southeast University national center of Technology Innovation for Electronic Design Automation Southeast University national Key Laboratory of Solid-State Microwave Devices and Circuits

The drain current （ID） of the n-channel GaN field-effecttransistor （n-FET） is influenced by the substrate-to-source bias voltage (VBS)（substrate bias effect）[1].Actually,nonzero VBSis also likely to occur in p-FET in real application,because the source electrode of p-FET is usually connected to high *** study reports the dependency between IDand VBSin p-FET for the first time,and analyzes the underlying mechanisms from the perspective of vertical electric field （EF） distribution.

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A Multifunctional Hydrogel with Multimodal Self-Powered Sensing Capability and Stable Direct Current Output for Outdoor Plant Monitoring Systems

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Nano-Micro Letters 2025年第4期17卷 1-24页

作者： Xinge Guo Luwei Wang Zhenyang Jin Chengkuo Lee Department of Electrical&Computer engineering National University of Singapore4 Engineering Drive 3Singapore 117576Singapore center for Intelligent Sensors and MEMS(CISM) National University of Singapore5 Engineering Drive 1Singapore 117608Singapore NUS Graduate School-Integrative Sciences and engineering Program(ISEP) National University of SingaporeSingapore 119077Singapore research center for Sustainable Urban Farming(SUrF) National University of SingaporeSingapore 117558Singapore

Smart farming with outdoor monitoring systems is critical to address food shortages and sustainability *** systems facilitate informed decisions that enhance efficiency in broader environmental *** outdoor systems equipped with energy harvesters and self-powered sensors often struggle with fluctuating energy sources,low durability under harsh conditions,non-transparent or non-biocompatible materials,and complex ***,a multifunctional hydrogel is developed,which can fulfill all the above requirements and build selfsustainable outdoor monitoring systems solely by *** can serve as a stable energy harvester that continuously generates direct current output with an average power density of 1.9 W m^(-3)for nearly 60 days of operation in normal environments(24℃,60%RH),with an energy density of around 1.36×10^(7)J m^(-3).It also shows good self-recoverability in severe environments(45℃,30%RH)in nearly 40 days of continuous ***,this hydrogel enables noninvasive and self-powered monitoring of leaf relative water content,providing critical data on evaluating plant health,previously obtainable only through invasive or high-power consumption *** potential extends to acting as other self-powered environmental *** multifunctional hydrogel enables self-sustainable outdoor systems with scalable and low-cost production,paving the way for future agriculture.

关键词： Self-powered sensor Hydrogel Energy harvester Outdoor farming Self-sustainable IoT

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Vacuum ammonia stripping from liquid digestate:Effects of pH,alkalinity,temperature,negative pressure and process optimization

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Journal of Environmental Sciences 2025年第3期149卷 638-650页

作者： Qiuhong Chen Donghai Yang Xiang Chen Xiankai Wang Bin Dong Xiaohu Dai State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China YANGTZE Eco-Environment engineering research center National Engineering Research Center of Eco-environment Protection for Yangtze River Economic BeltChina Three Gorges CorporationWuhan 430010China

High ammonia-nitrogen digestate has become a key bottleneck limiting the anaerobic digestion of organic solid *** ammonia stripping can simultaneously remove and recover ammonia nitrogen,which has attracted a lot of attention in recent *** investigate the parameter effects on the efficiency and mass transfer,five combination conditions(53℃ 15 kPa,60°C 20 kPa,65°C 25 kPa,72°C 35 kPa,and 81°C 50 kPa)were conducted for ammonia stripping of sludge *** results showed that 80%of ammonia nitrogen was stripped in 45 min for all experimental groups,but the ammonia transfer coefficient varied under different conditions,which increased with the rising of boiling point temperature,and reached the maximum value(39.0 mm/hr)at 81°C 50 *** ammonia nitrogen removal efficiency was more than 80%for 30 min vacuum stripping after adjusting the initial pH to above 9.5,and adjustment of the initial alkalinity also affects the pH value of liquid *** was found that pH and alkalinity are the key factors influencing the ammonia nitrogen dissociation and removal efficiency,while temperature and vacuum mainly affect the ammonia nitrogen mass transfer and removal *** terms of the mechanism of vacuum ammonia stripping,it underwent alkalinity destruction,pH enhancement,ammonia nitrogen dissociation,and free ammonia *** this study,two-stage experiments of alkalinity destruction and ammonia removal were also carried out,which showed that the two-stage configuration was beneficial for ammonia *** provides a theoretical basis and practical technology for the vacuum ammonia stripping from liquid digestate of organic solid waste.

关键词： Liquid digestate Vacuum ammonia stripping Alkalinity Mass transfer Process optimization

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