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Effect of valence and spin state on ethane dehydrogenation in Fe-S-1 catalyst

Journal of Energy Chemistry 2024年第10期97卷 677-686页

作者： Liusai Huang Yumeng Fo Peng zhang Shaojia song Xinxin zhang Xueqiu Wu Saeed Soltanali Jian Liu Weiyu song State Key Laboratory of Heavy Oil Processing China University of Petroleum (Beijing) China Petrochemical Research Institute PetroChina Company Limited Catalysis Technologies Development Division Research Institute of Petroleum Industry (RIPI)

Light alkanes non-oxidative dehydrogenation is an attractive non-oil route for olefins *** alkane dehydrogenation reaction is limited by thermodynamic equilibrium,and the C-H bond cleavage is commonly considered as the rate-determined *** valence state of metal sites in catalysts will influence the stabilization of the vital intermediate(i.e.,CxHy...Mδ+...H) during the C-H bond cleavage process,which in turn affects the catalytic ***,we explicitly investigated the effect of different valence states of framework-Fe in silicate-1 zeolite on ethane dehydrogenation reaction through the combination of experimental and theoretical ***（Ⅱ）-S-1 and Fe（Ⅲ）-S-1 catalysts are successfully synthesized by ligand-assisted in situ crystallization method,In-situ C2H6-FTIR shows the higher coverage of hydrocarbon intermediates on Fe（Ⅱ）-S-1,Under the same evaluation co nditio n,Fe（Ⅱ）-S-1 exhibits a higher space time yield of *** functional theory（DFT） results reveal that the more coordinate-unsaturated and electron-enriched Fe（Ⅱ） sites boost the first C-H bond activation by slight deformation and efficient electron donation with C2H5****,the second C-H bond cleavage on Fe（Ⅱ）-S-1 undergoes a spin-crossing process from quintet state to triplet state,which involves a two-electro n-two-orbital interaction,further promoting the formation of *** analysis is consistent with the experimental and DFT *** work could provide methodology for elucidating the effect of metal valence states on catalytic performance as well as offer guidance for designing more efficient Fe-zeolite catalysts.

关键词： DFT Electron-enriched Ethane dehydrogenation Iron Spin crossover

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Constructions of optimal binary locally repairable codes via intersection subspaces

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Science China(Information Sciences) 2024年第6期67卷 418-432页

作者： Wenqin zhang Deng TANG Chenhao YING yuan LUO School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University

Locally repairable codes（LRCs）, which can recover any symbol of a codeword by reading only a small number of other symbols, have been widely used in real-world distributed storage systems, such as Microsoft Azure Storage and Ceph Storage Cluster. Since binary linear LRCs can significantly reduce coding and decoding complexity, constructions of binary LRCs are of particular interest. The aim of this paper is to construct dimensional optimal binary LRCs with disjoint local repair groups. We introduce a method to connect intersection subspaces with binary LRCs and construct dimensional optimal binary linear LRCs with locality 2b（b 3） and minimum distance d 6 by employing intersection subspaces deduced from the direct sum. This method will sufficiently increase the number of possible repair groups of dimensional optimal LRCs, thus efficiently expanding the range of the construction parameters while keeping the largest code rates compared with all known binary linear LRCs with minimum distance d 6 and locality 2b.

关键词： locally repairable codes disjoint local repair groups distributed storage systems intersection subspaces direct sum

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Capacity Market Mechanism Design,Considering Network Optimization and Energy Transition

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1676-1687页

作者： Nan Shang Yihang song Xiang zhang You Lin China Southern Power Grid Co. Ltd.Guangzhou 510663China Southern Methodist University Junkins 3086251 Airline Road DallasTX 75205US

The coordination of enrgy transition,fixed cost recovery,and sufficient generation supply leads to a new challenge for a traditional capacity market ***,in order to better match network expansion at the same time,it is crucial to redesign the capacity market mechanism considering system *** this paper,a novel capacity market mechanism is proposed considering spot market operations,network expansion,and energy transition,which can minimize the total cost of capacity investment,network expansion,and generation operations,while satisfying the energy transition constraints and topology ***,the capacity market mechanism co-ordinated with spot market operations is illustrated,in which the energy transition and network constraints are ***,a bi-level optimization model is established where the trade organizers minimize the total cost of both investment and operations,subject to the spot power market simultaneously minimizing the local dispatching *** numerical results of a test system show that more economical capacity portfolios can be obtained by constructing reasonable transmission lines,thereby obtaining a more optimal market cost.A detailed multi-scenario simulation is further analyzed to verify the effectiveness of the proposed market mechanism.

关键词： Capacity market energy transition network expansion spot market operation

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Biological soil crusts and their potential applications in the sand land over Qinghai-Tibet Plateau

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Research in Cold and Arid Regions 2024年第1期16卷 20-29页

作者： yuan zhang BenLi Liu Key Laboratory of Desert and Desertification/Research Station of Gobi Desert Ecology and Environment in Dunhuang of Gansu Province(Dunhuang) Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China University of Chinese Academy of Sciences Beijing 100049China Academy of Plateau Science and Sustainability Qinghai Normal UniversityXiningQinghai 810008China

The Qinghai-Tibet Plateau is now experiencing ecological degradation risks as a result of climate change and human *** alpine grassland ecology in permafrost zones is fragile and susceptible to deterioration due to its high altitude,low temperature,and limited oxygen,which complicates the repair of damaged *** soil crusts(BSCs)are crucial for land restoration in plateau regions because they can thrive in harsh conditions and have environmentally beneficial *** biological soil crust(IBSC)has shown success in low-altitude desert regions,but may not be easily duplicated to the plateau ***,it is essential to do a comprehensive and multifaceted analysis of the basic theoretical comprehension and practical application of BSCs on the Tibetan *** review article aims to provide a brief summary of the ecological significance and the mechanisms related to the creation,growth,and progression of *** discusses the techniques used for cultivating BSCs in laboratories and using them in the field,focusing on the Qinghai-Tibet Plateau *** thoroughly discussed the potential and the required paths for further *** study may be used as a basis for selecting suitable microbial strains and accompanying supplemental actions for implementing IBSCs in the Qinghai-Tibet Plateau.

关键词： Biological soil crusts Qinghai-Tibet Plateau Alpine sand areas Inoculated biological soil crusts technology Algae Cyanobacteria

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Photonic neuromorphic architecture for tens-of-task lifelong learning

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Light(Science & Applications) 2024年第3期13卷 519-530页

作者： yuan Cheng Jianing zhang Tiankuang Zhou Yuyan Wang Zhihao Xu Xiaoyun yuan Lu Fang Sigma Laboratory Department of Electronic EngineeringTsinghua UniversityBeijing 100084China Beijing National Research Center for Information Science and Technology(BNRist) Beijing 100084China Institute for Brain and Cognitive Science Tsinghua University(THUIBCS)Beijing 100084China

Scalable,high-capacity,and low-power computing architecture is the primary assurance for increasingly manifold and large-scale machine learning *** electronic artificial agents by conventional power-hungry processors have faced the issues of energy and scaling walls,hindering them from the sustainable performance improvement and iterative multi-task *** to another modality of light,photonic computing has been progressively applied in high-efficient neuromorphic ***,we innovate a reconfigurable lifelong-learning optical neural network(L2 ONN),for highly-integrated tens-of-task machine intelligence with elaborated algorithm-hardware *** from the inherent sparsity and parallelism in massive photonic connections,L2 ONN learns each single task by adaptively activating sparse photonic neuron connections in the coherent light field,while incrementally acquiring expertise on various tasks by gradually enlarging the *** multi-task optical features are parallelly processed by multi-spectrum representations allocated with different *** evaluations on freespace and on-chip architectures confirm that for the first time,L2 ONN avoided the catastrophic forgetting issue of photonic computing,owning versatile skills on challenging tens-of-tasks(vision classification,voice recognition,medical diagnosis,etc.)with a single ***,L2 ONN achieves more than an order of magnitude higher efficiency than the representative electronic artificial neural networks,and 14×larger capacity than existing optical neural networks while maintaining competitive performance on each individual *** proposed photonic neuromorphic architecture points out a new form of lifelong learning scheme,permitting terminal/edge AI systems with light-speed efficiency and unprecedented scalability.

关键词： life neural versatile

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Oxidation behavior of 4774DD1 Ni-based single-crystal superalloy at 980℃ in air

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China Foundry 2024年第2期21卷 116-124页

作者： Yu Fang Ya-zhou Li Qiang Yang Qun-gong He Xiu-fang Gong Qian Duan Hai-yang song Fu Wang Qiong-yuan zhang Hong Zeng State Key Laboratory of Long-Life High Temperature Materials Dongfang Turbine Co.Ltd.Deyang 618000SichuanChina State Key Laboratory for Manufacturing System Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049China

The oxidation behavior of a novel Ni-based single-crystal 4774DD1 superalloy for industrial gas turbine applications was investigated by the isothermal oxidation at 980℃ and discontinuous oxidation weight gain *** phase constitution and morphology of surface oxides and the characteristics of the crosssection oxide film were analyzed by XRD,SEM and *** show that the oxidation kinetics of the 4774DD1 superalloy follows the cubic law,indicating its weak oxidation resistance at this *** the oxidation time increases,the composition of the oxide film evolves as following:One layer consisting of a bottom Al_(2)O_(3)sublayer and an upper(Al_(2)O_(3)+NiO)mixture sublayer after oxidized for 25 ***,two layers composed of an outermost small NiO discontinuous grain layer and an internal layer for 75 *** internal layer is consisted of the bottom Al_(2)O_(3)sublayer,an intermediate narrow CrTaO_(4)sublayer,and an upper(Al_(2)O_(3)+NiO)mixture *** two layers comprising an outermost relative continuous NiO layer with large grain size and an internal layer as the oxidation time increases to 125 *** internal layer is composed of the upper(Al_(2)O_(3)+NiO)mixture sublayer,an intermediate continuous(CrTaO_(4)+NiWO_(4))mixture sublayer,and a bottom Al_(2)O_(3)***,three layers consisting of an outermost(NiAl2O_(4)+NiCr2O_(4))mixture layer,an intermediate(CrTaO_(4)+NiWO_(4))mixture layer,and a bottom Al_(2)O_(3)layer for 200 h.

关键词： nickel-base single crystal superalloy oxidation kinetics oxide film microstructure mechanism

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CuInS_(2)quantum-dot-modified g-C_(3)N_(4)S-scheme heterojunction photocatalyst for hydrogen production and tetracycline degradation

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Journal of Materials Science & Technology 2024年第5期172卷 145-155页

作者： Jingjing zhang Yue Zhao Kezhen Qi Shu-yuan Liu College of Pharmacy Dali UniversityDali 671000China Department of Pharmacology Shenyang Medical CollegeShenyang 110034China

CuInS_(2)quantum-dot(CIS QD)-modified g-C_(3)N_(4)(CN)catalysts(CIS/CN)were prepared with the aid of an in-situ growth *** as-obtained photocatalysts were explored by measuring their crystallinity,surface morphology,binding energy and light absorption *** photocatalytic efficiency of the pho-tocatalysts was evaluated through photocatalytic water splitting for hydrogen production and tetracycline(TC)antibiotic degradation under the simulated solar light and visible light *** optimized sample(10CIS/CN)showed the best photocatalytic activity:producing 102.4μmol g^(-1)h^(-1)of hydrogen in 1 h,or degrading 52.16%of TC in 120 min,which were respectively 48 or 3.4 times higher than the photocatalytic activity of CN *** enhancement in the efficiency of the composite system was prin-cipally accredited to the enlargement of light absorption,the more effective in charge transfer and the dropping of the charge carrier pair recombination through a formed S-scheme heterojunctional *** work is an effort to adjust CN-based polysulfide QD for speedy *** enriched photo-catalytic activity grants a new sense for adjusting the optical properties of CN.

关键词： CuInS_(2)QDs g-C_(3)N_(4) Photocatalysis Hydrogen production S-scheme heterojunction

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Imide-based covalent organic framework with excellent cyclability as an anode material for lithium-ion battery

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Chinese Chemical Letters 2024年第6期35卷 206-210页

作者： Yue Qian Zhoujia Liu Haixin song Ruize Yin Hanni Yang Siyang Li Weiwei Xiong Saisai yuan Junhao zhang Huan Pang School of Environmental&Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Chemistry&Chemical Engineering Yangzhou UniversityYangzhou 225009China Shandong Key Laboratory of Biochemical Analysis College of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdao 266042China

Covalent organic frameworks(COFs)exhibiting reversible redox behaviors have been identified as promising candidates for constructing electrode materials in lithium-ion batteries(LIBs).However,their extensive application has been limited due to finite redox sites and poor structural *** this study,we design and synthesize a novel polyimide covalent organic framework(PI-COF)using the traditional solvothermal method and successfully apply it as an anode material for *** large conjugated structure of PI-COF accelerates charge transfer,while its large surface area provides more active sites,making PI-COF an attractive anode material for ***,the PI-COF anode material demonstrates high reversible specific capacity and excellent long-term cycling stability due to its COF ***,the PI-COF electrodes deliver a specific capacity of 800 m Ah/g at a current density of 200 m A/g after 200 cycles,while a specific capacity of 450 m Ah/g at a current density of 1000 m A/g is sustained after 800 *** outstanding lithium storage capacity,particularly the satisfactory long-term cycling stability,establishes PI-COF as a promising material for LIBs.

关键词： Ethylenediaminetetraacetic dianhydride Covalent organic frameworks Polyimide Lithium-ion battery Anode material

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Mesoporous molecular sieve confined phase change materials with high absorption,enhanced thermal conductivity,and cooling energy charging/discharging capacity

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Frontiers of Materials Science 2024年第1期18卷 1-14页

作者： Qi zhang Chongyang Liu Xuehong Wu Xueling zhang Jun song School of Energy and Power Engineering Zhengzhou University of Light IndustryZhengzhou 450007China

The biggest challenge for organic phase change materials(PCMs)used in cold energy storage is to maintain high heat storage capacity while reducing the leakage risk of PCMs during the phase transition *** is crucial for expanding their applications in the more demanding cold storage *** this study,novel formstable low-temperature composite PCMs are prepared with mesoporous materials,namely SBA-15 and CMK-3(which are prepared using the template method),as supporting matrices and dodecane as the *** to the combined effects of capillary forces within mesoporous materials and interactions among dodecane molecules,both dodecane/SBA-15 and dodecane/CMK-3 exhibit outstanding shape stability and thermal cycling stability even after 200 heating/cooling *** comparison to those of dodecane/SBA-15,dodecane/CMK-3 exhibits superior cold storage performance and higher thermal ***,the phase transition temperature of dodecane/CMK-3 is-8.81℃ with a latent heat of 122.4 J·g^(-1).Additionally,it has a thermal conductivity of 1.21 W·m^(-1)·K^(-1),which is 9.45 times that of dodecane *** these highlight its significant potential for applications in the area of cold energy storage.

关键词： cold energy storage phase change material mesoporous molecular sieve CMK-3 SBA-15 cooling energy charging/discharging capacity

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Taiji-TianQin-LISA network:Precisely measuring the Hubble constant using both bright and dark sirens

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 59-77页

作者： Shang-Jie Jin Ye-Zhu zhang Ji-Yu song Jing-Fei zhang Xin zhang Key Laboratory of Cosmology and Astrophysics(Liaoning)&College of Sciences Northeastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern UniversityShenyang 110819China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China

In the coming decades,the space-based gravitational-wave(GW)detectors such as Taiji,TianQin,and LISA are expected to form a network capable of detecting millihertz GWs emitted by the mergers of massive black hole binaries(MBHBs).In this work,we investigate the potential of GW standard sirens from the Taiji-TianQin-LISA network in constraining cosmological *** the optimistic scenario in which electromagnetic(EM)counterparts can be detected,we predict the number of detectable bright sirens based on three different MBHB population models,i.e.,popⅢ,Q3d,and *** results show that the TaijiTianQin-LISA network alone could achieve a constraint precision of 0.9%for the Hubble constant,meeting the standard of precision ***,the Taiji-TianQin-LISA network could effectively break the cosmological parameter degeneracies generated by the CMB data,particularly in the dynamical dark energy *** combined with the CMB data,the joint CMB+Taiji-TianQin-LISA data offerσ(w)=0.036 in the wCDM model,which is close to the latest constraint result obtained from the CMB+SN *** also consider a conservative scenario in which EM counterparts are not *** to the precise sky localizations of MBHBs by the Taiji-TianQin-LISA network,the constraint precision of the Hubble constant is expected to reach 1.2%.In conclusion,the GW standard sirens from the Taiji-TianQin-LISA network will play a critical role in helping solve the Hubble tension and shedding light on the nature of dark energy.

关键词： space-based gravitational wave detection standard sirens the Taiji-TianQin-LISA network the Hubble constant dark energy

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