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An aqueous magnesium-ion hybrid supercapacitor operated at-50℃

Green Energy & Environment 2024年第4期9卷 702-712页

作者： Guoshen Yang Gangrui Qu Chi Fang Jie Deng Xianqi Xu Yinghao xie Tian Sun Yachao Zhu Jiaxin Zheng hang Zhou School of Electronic and Computer Engineering Peking University Shenzhen Graduate SchoolShenzhen518055China School of Advanced Materials Peking University Shenzhen Graduate SchoolShenzhenChina College of Food and Biological Engineering Chengdu UniversityChengdu610106China Institute Charles Gerhardt Montpellier UMR 5253Universitae MontpellierMontpellierCC 1502France

The recent advances in aqueous magnesium-ion hybrid supercapacitor(MHSC)have attracted great attention as it brings together the benefits of high energy density,high power density,and synchronously addresses cost and safety issues.However,the freeze of aqueous electrolytes discourages aqueous MHSC from operating at low-temperature conditions.Here,a low-concentration aqueous solution of 4 mol L^(-1) Mg(ClO_(4))_(2) is devised for its low freezing point(-67℃)and ultra-high ionic conductivity(3.37 mS cm^(-1) at-50℃).Both physical characterizations and computational simulations revealed that the Mg(ClO_(4))_(2) can effectively disrupt the original hydrogen bond network among water molecules via transmuting the electrolyte structure,thus yielding a low freezing point.Thus,the Mg(ClO_(4))_(2) electrolytes endue aqueous MHSC with a wider temperature operation range(-50℃–25℃)and a higher energy density of 103.9 Wh kg^(-1) at 3.68 kW kg^(-1) over commonly used magnesium salts(i.e.,MgSO_(4) and Mg(NO_(3))_(2))electrolytes.Furthermore,a quasi-solid-state MHSC based on polyacrylamide-based hydrogel electrolyte holds superior low-temperature performance,excellentﬂexibility,and high safety.This work pioneers a convenient,cheap,and eco-friendly tactic to procure low-temperature aqueous magnesium-ion energy storage device.

关键词： Low-concentration aqueous electrolyte Anti-freezing property Magnesium-ion hybrid supercapacitor High energy density

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Water-soluble brown carbon in atmospheric aerosols from the resource-dependent cities:Optical properties,chemical compositions and sources

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Journal of Environmental Sciences 2024年第4期138卷 74-87页

作者： Haoji Wang yue Su Yangzheng Liu Fei xie Xingjun Zhou Ruihong yu Changwei Lü Jiang He School of Ecology and Environment Inner Mongolia UniversityHohhot 010021China Institute of Environmental Geology Inner Mongolia UniversityHohhot 010021China Environmental Monitoring Center of Inner Mongolia Hohhot 010011China

As a vital type of light-absorbing aerosol,brown carbon(BrC)presents inherent associations with atmospheric photochemistry and climate change.However,the understanding of the chemical and optical properties of BrC is limited,especially in some resource-dependent cities with long heating periods in northwest China.This study showed that the annual average abundances of Water-soluble BrC(WS-BrC)were 9.33±7.42 and 8.69±6.29μg/m^(3)in Baotou and Wuhai and the concentrations,absorption coefficient(Abs_(365)),and mass absorption efficiency(MAE365)of WS-BrC presented significant seasonal patterns,with high values in the heating season and low values in the non-heating season;while showing opposite seasonal trends for the Absorption Angstr?m exponent(AAE_(300-400)).Comparatively,the levels of WS-BrC in developing regions(such as cities in Asia)were higher than those in developed regions(such as cities in Europe and Australia),indicating the significant differences in energy consumption in these regions.By combining fluorescence excitation-emission matrix(EEM)spectra with the parallel factor(PARAFAC)model,humic-like(C1 and C2)and proteinlike(C3)substances were identified,and accounted for 61.40%±4.66%and 38.6%±3.78%at Baotou,and 60.33%±6.29%and 39.67%±4.17%at Wuhai,respectively.The results of source apportionment suggested that the potential source regions of WS-BrC varied in heating vs.non-heating seasons and that the properties of WS-BrC significantly depended on primary emissions(e.g.,combustion emissions)and secondary formation.

关键词： Water-soluble brown carbon Atmospheric aerosols Optical properties PARAFAC Source apportionment

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Combining graph neural network with deep reinforcement learning for resource allocation in computing force networks

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Frontiers of Information Technology & Electronic Engineering 2024年第5期25卷 701-712页

作者： Xueying HAN Mingxi xie Ke yu Xiaohong HUANG Zongpeng DU Huijuan YAO School of Computer Science Beijing University of Posts and TelecommunicationsBeijing 100876China School of Artificial Intelligence Beijing University of Posts and TelecommunicationsBeijing 100876China Department of Infrastructure Network Technology Research China Mobile Research InstituteBeijing 100032China

Fueled by the explosive growth of ultra-low-latency and real-time applications with specific computing and network performance requirements,the computing force network(CFN)has become a hot research subject.The primary CFN challenge is to leverage network resources and computing resources.Although recent advances in deep reinforcement learning(DRL)have brought significant improvement in network optimization,these methods still suffer from topology changes and fail to generalize for those topologies not seen in training.This paper proposes a graph neural network(GNN)based DRL framework to accommodate network trafic and computing resources jointly and efficiently.By taking advantage of the generalization capability in GNN,the proposed method can operate over variable topologies and obtain higher performance than the other DRL methods.

关键词： Computing force network Routing optimization Deep learning Graph neural network Resource allocation

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Atomically dispersed Ni electrocatalyst for superior urea-assisted water splitting

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Journal of Energy Chemistry 2024年第3期90卷 1-6,I0002页

作者： Fang Luo Shuyuan Pan yuhua xie Chen Li Yingjie yu Zehui Yang College of Materials Science and Engineering State Key Laboratory of New Textile Materials&Advanced Processing TechnologyWuhan Textile UniversityWuhan 430200China Hubei Hydrogen Energy Technology Innovation Center Faculty of Materials Science and ChemistryChina University of GeosciencesWuhan 430074HubeiChina

Urea oxidation reaction(UOR) has been selected as substitution for oxygen evolution reaction ascribing to its low thermodynamic voltage as well as utilization of nickel as electrocatalyst.Herein,we report the formation of nickel single atoms(Ni-SAs) as exceptional bifunctional electrocatalyst toward UOR and hydrogen evolution reaction(HER) in urea-assisted water splitting.In UOR catalysis,Ni-SAs perform a superior catalytic performance than Ni-NP/NC and Pt/C ascribing to the formation of HOO-Ni-N_(4) structure evidenced by in-situ Raman spectroscopy,corresponding to a boosted mass activity by 175-fold at 1.4 V vs.RHE than Ni-NP/NC.Furthermore,Ni-SAs requires only 450 mV overpotential to obtain HER current density of 500 mA cm^(-2).136 mA cm^(-2) is achieved in urea-assisted water splitting at1.7 V for Ni-SAs,boosted by 5.7 times than Pt/C-IrO_(2) driven water splitting.

关键词： Urea oxidation reaction Hydrogen evolution reaction Nickel single atoms Water splitting

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Adaptive detection of range-spread targets in homogeneous and partially homogeneous clutter plus subspace interference

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Journal of Systems Engineering and Electronics 2024年第1期35卷 43-54页

作者： JIAN Tao HE Jia WANG Bencai LIU yu XU Congan xie Zikeng Research Institute of Information Fusion Naval Aviation UniversityYantai 264001China Air Force Early Warning Academy Wuhan 430019China

Adaptive detection of range-spread targets is considered in the presence of subspace interference plus Gaussian clutter with unknown covariance matrix.The target signal and interference are supposed to lie in two linearly independent subspaces with deterministic but unknown coordinates.Relying on the two-step criteria,two adaptive detectors based on Gradient tests are proposed,in homogeneous and partially homogeneous clutter plus subspace interference,respectively.Both of the proposed detectors exhibit theoretically constant false alarm rate property against unknown clutter covariance matrix as well as the power level.Numerical results show that,the proposed detectors have better performance than their existing counterparts,especially for mismatches in the signal steering vectors.

关键词： adaptive detection subspace interference constant false alarm rate Gradient test partially homogeneous environment

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Sulfated Cyclocarya paliurus polysaccharides exert immunomodulatory potential on macrophages via Toll-like receptor 4 mediated MAPK/NF-κB signaling pathways

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Food Science and Human Wellness 2024年第1期13卷 115-123页

作者： yue yu Haibin Zhu Mingyue Shen Qiang yu Yi Chen Shiru Mo Jianhua xie State Key Laboratory of Food Science and Technology Nanchang UniversityNanchang 330047China International Institute of Food Innovation Nanchang UniversityNanchang 330200China

The biological activity of plant polysaccharides can be enhanced by sulfated modification.In this study,the immunomodulatory effect of sulfated Cyclocarya paliurus polysaccharides(SCP3)on macrophages RAW264.7 and its potential molecular mechanism were investigated.Results showed that SCP3 at 25-100μg/m L increased viability and improved phagocytosis of RAW264.7 cells.Meanwhile,SCP3 could activate mitogen-activated protein kinase(MAPK)and nuclear factor kappa B(NF-κB)signaling pathways,which increased the phosphorylation of Erk1/2,JNK,p38 and NF-κB p65,promoting secretion of cytokines tumor necrosis factorα(TNF-α),interleukin 6(IL-6)and nitric oxide(NO)as well as the production of reactive oxygen species(ROS).In addition,Toll-like receptor 4(TLR4)receptor inhibitors were able to block the production of NO and TNF-αby SCP3-stimulated macrophages.Based on Western blot analysis and validation using specific inhibitors against MAPK and NF-κB signaling pathways,the results demonstrated that SCP3 induced macrophages activation and enhanced TNF-αand NO production via TLR4-mediated MAPK and NF-κB pathways.In summary,SCP3 has significant immunomodulatory potential.The underlying molecular mechanism was that SCP3 activates macrophages via TLR4 receptors to promote ROS production,which in turn activates the downstream MAPK/NF-κB signaling pathway and then increases the secretion levels of cytokines and NO.

关键词： Cyclocarya paliurus Sulfated polysaccharides Macrophages Immunomodulatory Mechanism

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An effective'salt in dimethyl sulfoxide/water'electrolyte enables high-voltage supercapacitor operated at-50℃

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Journal of Energy Chemistry 2024年第6期93卷 361-367,I0009页

作者： Yingbin Liu Chang yu Xuedan Song Siyi Hou Shuqin Lan Jinhe yu yuanyang xie Jieshan Qiu State Key Lab of Fine Chemicals Frontier Science Center for Smart MaterialsSchool of Chemical EngineeringLiaoning Key Lab for Energy Materials and Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina School of Chemistry Frontier Science Center for Smart MaterialsLiaoning Key Lab for Energy Materials and Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina College of Chemical Engineering State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Compared with organic electrolytes,aqueous electrolytes exhibit significantly higher ionic conductivity and possess inherent safety features,showcasing unique advantages in supercapacitors.However,challenges remain for low-salt aqueous electrolytes operating at high voltage and low temperature.Herein,we report a low-salt(0.87 m,m means mol kg^(-1))'salt in dimethyl sulfoxide/water'hybrid electrolyte with non-flammability via hybridizing aqueous electrolyte with an organic co-solvent of dimethyl sulfoxide(hydrogen bond acceptor).As a result,the 0.87 m hybrid electrolyte exhibits enhanced electrochemical stability,a freezing temperature below-50℃,and an outstanding ionic conductivity of 0.52mS cm~(-1)at-50℃.Dimethyl sulfoxide can anchor water molecules through intermolecular hydrogen bond interaction,effectively reinforcing the stability of water in the hybrid electrolyte.Furthermore,the interaction between dimethyl sulfoxide and water molecules diminishes the involvement of water in the generation of ordered ice crystals,finally facilitating the low-temperature performance of the hybrid electrolyte.When paired with the 0.87 m'salt in dimethyl sulfoxide/water'hybrid electrolyte,the symmetric supercapacitor presents a 2.0 V high operating voltage at 25℃,and can operate stably at-50℃.Importantly,the suppressed electrochemical reaction of water at-50℃further leads to the symmetric supercapacitor operated at a higher voltage of 2.6 V.This modification strategy opens an effective avenue to develop low-salt electrolytes for high-voltage and low-temperature aqueous supercapacitors.

关键词： Dimethyl sulfoxide Co-solvent High voltage Low temperature Supercapacitors

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Fully spin-polarized, valley-polarized and spin-valley-polarized electron beam splitters utilizing zero-line modes in a three-terminal device

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Chinese Physics B 2024年第6期33卷 596-603页

作者：吕小龙杨加恩谢航 College of Science Guangxi University of Science and TechnologyLiuzhou 545006China College of Physics Chongqing UniversityChongqing 401331China Chongqing Key Laboratory for Strongly-Coupled Physics Chongqing UniversityChongqing 401331China

Topological zero-line modes(ZLMs) with spin and valley degrees of freedom give rise to spin, valley and spinvalley transport, which support a platform for exploring quantum transport physics and potential applications in spintronic/valleytronic devices. In this work, we investigate the beam-splitting behaviors of the charge current due to the ZLMs in a three-terminal system. We show that with certain combinations of ZLMs, the incident charge current along the interface between different topological phases can be divided into different polarized currents with unit transmittance in two outgoing terminals. As a result, fully spin-polarized, valley-polarized and spin-valley-polarized electron beam splitters are generated. The mechanism of these splitters is attributed to the cooperative effects of the distribution of the ZLMs and the intervalley and intravalley scatterings that are modulated by the wave-vector mismatch and group velocity mismatch. Interestingly, half-quantized transmittance of these scatterings is found in a fully spin-valley-polarized electron beam splitter.Furthermore, the results indicate that these splitters can be applicable to graphene, silicene, germanene and stanene due to their robustness against the spin–orbit coupling. Our findings offer a new way to understand the transport mechanism and investigate the promising applications of ZLMs.

关键词： topological zero-line modes spin polarization valley polarization quantum transport

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Mass extinctions, their causes and consequences: an interview with Douglas H.Erwin and Shuzhong Shen

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National Science Review 2024年第1期11卷 66-70页

作者： Shucheng xie State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences at Wuhan

‘Mass extinctions’ have been a hot topic for several decades. What triggers a mass extinction? How does a mass extinction impact the evolution of life? How does our ecosystem recover after a mass extinction? These questions attracted the interest of both scientists and the public alike.NSR spoke to two renowned researchers in the field of mass extinctions: Prof. Douglas H. Erwin from the National Museum of Natural History of the USA, and Prof. Shuzhong Shen from Nanjing University, China.

关键词： Stratigraphy

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Synthesis of Planar-Chiral[2.2]Paracyclophane-Based Oxazole-Pyrimidine Ligands and Application in Nickel-Catalyzed 1,2-Reduction ofα,β-Unsaturated Ketones

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Chinese Journal of Chemistry 2024年第7期42卷 705-710页

作者： Juan Wang Qing-Xian xie Xiang Li Chang-Bin yu Yong-Gui Zhou School of Chemistry Dalian University of Technology2 Linggong RoadDalianLiaoning 116024China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning 116023China

The planar-chiral ligands have been widely applied as a class of unique and significant ligands in asymmetric catalysis.Among them,chiral[2.2]paracycyclophane has emerged as a privileged type of planar-chiral framework and has been utilized as an important toolbox due to their structural stability.Herein,we design and synthesize[2.2]paracyclophane-derived oxazole-pyrimidine ligands(abberviated as PYMCOX).These N,N-ligands with stable properties,rigid structure and large steric hindrance performed successfully in nickel-catalyzed asymmetric 1,2-reduction ofα,β-unsaturated ketones,affording the chiral allylic alcohols with up to 99%yield and 99%ee.Meanwhile,this reduction reaction could be conducted on gram-scale without loss of activity and enantioselectivity,and the chiral ligand could be conveniently recovered with high yield.

关键词： Oxazole-pyrimidine ligands Planar chirality Nickel Hydroboration Asymmetric synthesis

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