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Asymmetric configuration activating lattice oxygen via weakening d-p orbital hybridization for efficient C/N separation in urea overall electrolysis

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Journal of Energy Chemistry 2024年第5期92卷 233-239页

作者： Chongchong Liu Peifang wang Bin Hu Xiaoli Liu rong Huang Gang Zhou Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education College of EnvironmentHohai UniversityNanjing 210098JiangsuChina

Urea oxidation reaction(UOR)is proposed as an exemplary half-reaction in renewable energy applications because of its low thermodynamical ***,challenges persist due to sluggish reaction kinetics and complex by-products *** this end,we introduce the lattice oxygen oxidation mechanism(LOM),propelling a novel UOR route using a modified CoFe layered double hydroxide(LDH)catalyst termed *** calculations and in-situ characterizations highlight the activated lattice oxygen(O_(L))within CFRO-7 as pivotal sites for UOR,optimizing the reaction pathway and accelerating the *** the urea overall electrolysis application,the LOM route only requires a low voltage of 1.54 V to offer a high current of 100 mA cm^(-2) for long-term utilization(>48 h).Importantly,the by-product NCO^(-)−is significantly suppressed,while the CO_(2)2/N_(2) separation is efficiently *** work proposed a pioneering paradigm,invoking the LOM pathway in urea electrolysis to expedite reaction dynamics and enhance product selectivity.

关键词： Lattice oxygen Urea oxidation reaction Overall electrolysis Products selectivity

Applying heteroatom co-doped carbon nanotube for manifesting high performance in the electrochemical reduction of aqueous nitrogen oxide by gold nanoparticles

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Nano Research 2024年第3期17卷 1151-1164页

作者： Jane Chung Haibo Yin rong wang Yunlong wang Junyang Zhang Yue Peng Joung Woo Han Seongyun Ryu Junhua Li State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China EHS Research Center Samsung Electronics Co.Ltd.Gyeonggi-do 18448Republic of Korea

Electrochemical NO-to-NH_(3) under ambient conditions could be a viable alternative having advantages in terms of energy consumption and exhaust gas recycling of NO,replacing a traditional ammonia synthesis method of the Haber–Bosch *** synthesizing boron(B-)and nitrogen(N-)co-doped carbon nanotube(CNT)based gold(Au)catalysts,B-dopants elevate the conductivity of carbon nanotube by sp2 hybridization on graphene and implant B–N domains within the graphene layer,and result in facilitating the embedding amount of Au accompanied by high dispersibility with low particle *** density functional theory(DFT)calculations elucidate that the electron cloud transmitted from B-dopant to the active site of Au induces the Lewis acidic site,and the O-distal pathway occurs following a spontaneous *** of the electron-deficient B-doping area accompanied by N-defects and B–O edges retains the major valence state of Au as Au^(δ+),and suppresses hydrogen evolution reaction(HER)by repulsing the hindrance of H*.This record exhibits the highest faradaic efficiency(FE)of 94.7%,and NH_(3) yield rate of 1877.4μg·h^(-1)·mg_(cat)^(-1),which is the optimal yield over energy consumption in the field of the ambient reduction of aqueous NO.

关键词： boron heteroatom nitrogen defect gold nanoparticles valence states of gold electrochemical NO-to-NH3

Recent advances in visible light-mediated chemical transformations of enaminones

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Chinese Chemical Letters 2024年第2期35卷 4-15页

作者： Yu Han Liyun Zhou Chengyu wang Shangti Feng rong Ma Jie-Ping Wan College of Chemistry and Chemical Engineering Jiangxi Normal UniversityNanchang 330022China School of Chemistry and Chemical Engineering Linyi UniversityLinyi 276000China Linyi Sanfeng Chemical Co. Ltd.Linyi 276000China

Enaminones,which possesses both the nucleophilic enamine as well as electrophilic enone structures,are well known versatile building blocks in organic ***,visible light-mediated reactions have emerged as useful synthetic strategy with enhanced *** the last decade,various photochemical transformations of enaminones have been developed to construct cyclic or acyclic *** this review,we describe the recent advances in visible light-mediated chemical transformations of *** discussion on the reaction mechanism of the related reactions is given to provide guide to the ***,a summary on the existing challenges and the future outlook towards the development of practical photocatalytic reactions of enaminones is also presented.

关键词： Enaminone Visible light C-H functionalization C=C bond cleavage Cyclization Multicomponent reactions

Recent progress on electro-sorption technology for lithium recovery from aqueous sources

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Nano Research 2024年第4期17卷 2563-2573页

作者： Qichen Lu Peng Liu Tianyi Zhou Ruling Huang Kexin Zhang Lin Hu rong Liu Zhibo Ren Jinyi wang Xiaolong wang Huaneng Clean Energy Research Institute Beijing 102209China

Lithium is known as the“white petroleum”of the electrification era,and the global demand for lithium grows rapidly with the quick development of new energy *** aqueous solutions,such as salt lake brine,underground brine,and seawater,have large lithium reserves,thus this kind of lithium resource has become a research hotspot *** with other lithium extraction technologies,electro-sorption method shows good prospects for practical applications with advantages in the aspects of efficiency,recovery ratio,cost,and ***,this review covers recent progress on electro-sorption technology for lithium recovery from aqueous solutions,including the concept illustration,research progress of the applied working electrodes and counter electrodes,and the evaluation indicators of electro-sorption ***,some prospects for the development of this technology are also *** hope this review is beneficial for the construction of high-efficient electrochemical lithium recovery system to achieve an adequate lithium supply in the future.

关键词： lithium extraction electro-sorption technology lithium selective electrode counter electrode system evaluation method

High speed laser cladding as a new approach to prepare ultra-high temperature ceramic coatings

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Journal of Advanced Ceramics 2024年第2期13卷 143-154页

作者： Qiyao Deng Pengfei He chuan Sun Yang Li Yue Xing Yujie wang Jinglong Li Xiubing Liang Xin wang Yujie Zhou Yujun Cai National-Local Joint Engineering Laboratory of Intelligent Manufacturing Oriented Automobile Die&Mould Tianjin University of Technology and EducationTianjin 300222China Defense Innovation Institute Academy of Military ScienceBeijing 100071China School of mechanical engineering Tianjin University of Technology and EducationTianjin 300222China Scientific and Technological Innovation Center Beijing 100012China

Ultra-high temperature ceramic(UHTC)coatings are used to protect the hot-end components of hypervelocity aerocrafts from thermal *** study provides a new approach to fabricate UHTC coatings with high speed laser cladding(HSLC)technology,and places more emphasis on investigating the formation mechanism,phase compositions,and mechanical properties of HSLC-UHTC *** show that a well-bonded interface between the coating and the tantalum alloy substrate can be *** coating is mainly composed of(Zr,Ta)C ceramic solid solution phase with a content of higher than 90% by volume and Ta(W)metal solid solution *** a relatively high powder feeding rate,the ZrC ceramic phase appears in the coating while a dense ZrC UHTC top layer with a thickness of up to~50μm is successfully *** for the mechanical properties of the HSLC coatings,the fracture toughness of the coating decreases with the increase of powder feeding *** increase of carbide solid solution phase can significantly improve the high temperature microhardness(552.7±1.8 HV0.5@1000℃).The innovative design of HSLC ZrC-based coatings on refractory alloys accomplishes continuous transitions on microstructure and properties from the substrate to the UHTC top layer,which is a very promising candidate scheme for thermal protection coating.

关键词： high speed laser cladding(HSLC) ultra-high temperature ceramic(UHTC) thermal protection coating microstructure mechanical properties

Urban growth scenario projection using heuristic cellular automata in arid areas considering the drought impact

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Journal of Arid Land 2024年第4期16卷 580-601页

作者： TANG Xiaoyan FENG Yongjiu LEI Zhenkun CHEN Shurui wang Jiafeng wang rong TANG Panli wang Mian JIN Yanmin TONG Xiaohua College of Surveying&Geo-Informatics Tongji UniversityShanghai 200092China Shanghai Key Laboratory of Space Mapping and Remote Sensing for Planetary Exploration Tongji UniversityShanghai 200092China

Arid areas with low precipitation and sparse vegetation typically yield compact urban pattern,and drought directly impacts urban site selection,growth processes,and future *** simulation and projection based on cellular automata(CA)models is important to achieve sustainable urban development in arid *** developed a new CA model using bat algorithm(BA)named bat algorithm-probability-of-occurrence-cellular automata(BA-POO-CA)model by considering drought constraint to accurately delineate urban growth patterns and project future scenarios of Urumqi City and its surrounding areas,located in Xinjiang Uygur Autonomous Region,*** calibrated the BA-POO-CA model for the drought-prone study area with 2000 and 2010 data and validated the model with 2010 and 2020 data,and finally projected its urban scenarios in *** results showed that BA-POO-CA model yielded overall accuracy of 97.70%and figure-of-merits(FOMs)of 35.50%in 2010,and 97.70%and 26.70%in 2020,*** inclusion of drought intensity factor improved the performance of BA-POO-CA model in terms of FOMs,with increases of 5.50%in 2010 and 7.90%in 2020 than the model excluding drought intensity *** suggested that the urban growth of Urumqi City was affected by drought,and therefore taking drought intensity factor into account would contribute to simulation *** BA-POO-CA model including drought intensity factor was used to project two possible scenarios(i.e.,business-as-usual(BAU)scenario and ecological scenario)in *** the BAU scenario,the urban growth dominated mainly in urban fringe areas,especially in the northern part of Toutunhe District,Xinshi District,and Midong *** exceptional and extreme drought areas as a spatial constraint,the urban growth was mainly concentrated in the"main urban areas-Changji-Hutubi"corridor urban pattern in the ecological *** results of this research can help to adjust urban planning and development *** mode

关键词： bat algorithm cellular automata(CA) probability-of-occurrence drought intensity algorithm-probability-of-occurrence-cellular automata(BA-POO-CA)model arid areas

Optimization of resource allocation in FDD massive MIMO systems

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Digital Communications and Networks 2024年第1期10卷 117-125页

作者： Jun Cai chuan Yin Youwei Ding School of Artificial Intelligence and Information Technology Nanjing University of Chinese MedicineNanjing 210046China School of Electronic and Information Hangzhou Dianzi UniversityHangzhou 310018ZhejiangChina

The performance of massive MIMO systems relies heavily on the availability of Channel State Information at the Transmitter(CSIT).A large amount of work has been devoted to reducing the CSIT acquisition overhead at the pilot training and/or CsI feedback *** fact,the downlink communication generally includes three stages,i.e.,pilot training,CsI feedback,and data *** three stages are mutually related and jointly determine the overall system ***,there exist few studies on the reduction of csIT acquisition overhead from the global point of *** this paper,we integrate the Minimum Mean Square Error(MMSE)channel estimation,Random Vector Quantization(RVQ)based limited feedback and Maximal Ratio Combining(MRC)precoding into a unified framework for investigating the resource allocation *** particular,we first approximate the covariance matrix of the quantization error with a simple expression and derive an analytical expression of the received Signal-to-Noise Ratio(SNR)based on the deterministic equivalence *** the three performance metrics(the spectral efficiency,energy efficiency,and total energy consumption)oriented problems are formulated *** practical system requirements,these three metrics can be collaboratively ***,we propose an optimization solver to derive the optimal partition of channel coherence *** results verify the benefits of the proposed resource allocation schemes under three different scenarios and illustrate the tradeoff of resource allocation between three stages.

关键词： Massive MIMO FDD CSIT Resource allocation

Triggering triplet excitons of carbon nanodots through nanospace domain confinement for multicolor phosphorescence in aqueous solution

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Nano Research 2024年第7期17卷 6534-6543页

作者： Ya-chuan Liang Qing Cao Yuan Deng Yong wang Kai-Kai Liu Chong-Xin Shan School of Electronics and Information Zhengzhou University of Light IndustryZhengzhou 450002China Henan Key Laboratory of Diamond Optoelectronic Material and Devices Key Laboratory of Material PhysicsMinistry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450001China Academy for Quantum Science and Technology Zhengzhou University of Light IndustryZhengzhou 450002China Institute of Quantum Materials and Physics Henan Academy of SciencesZhengzhou 450046China

Easy non-radiative decay property of long-lived triplet excitons in aqueous solution obstructs their applications in aquatic *** reported phosphorescence phenomena in aqueous solution have excited researchers enormously but achieving full-color water-soluble phosphorescent carbon nanodots(CNDs)is still a challenging ***,full-color phosphorescence of water-soluble CNDs has been demonstrated by triggering their triplet excitons through nanospace domain confinement,and Förster energy resonance transfer is used for further tuning phosphorescence *** phosphorescence spans across most of the visible spectrum,ranging from 400 to 700 *** an aqueous solution,the CNDs exhibits blue,green,and red phosphorescence,lasting for approximately 6,10,and 7 s,***,the phosphorescence quantum yields are 11.85%,8.6%and 3.56%,making them readily discernible to the naked eyes and laying a solid foundation for practical ***,phosphorescence flexible optical display and bioimaging have been demonstrated by using the multicolor CNDs-based nanomaterials,showing distinct superiority for accuracy and complete display and imaging in complex emission background.

关键词： carbon nanodots triplet excitons multicolor aqueous solution

Fracture behavior and mechanism of highly fragmented steel cylindrical shell under explosive loading

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Defence Technology（防务技术） 2024年第6期36卷 122-132页

作者： Kang wang Peng Chen Xingyun Sun Yufeng Liu Jiayu Meng Xiaoyuan Li Xiongwei Zheng chuan Xiao Xi'an Modern Chemistry Research Institute Xi'an 710065China Shanxi Jiangyang Chemical Company Limited Taiyuan 030051China Central Iron&Steel Research Institute Company Limited Beijing 100081China China Research and Development Academy of Machinery Equipment Beijing 100089China

An in-depth understanding of the fracture behavior and mechanism of metallic shells under internal explosive loading can help develop material designs for warheads and regulate the quantity and mass distribution of the fragments *** study investigated the fragmentation performance of a new high-carbon silicon-manganese(HCSiMn)steel cylindrical shell through fragment recovery *** with the conventional 45Cr steel shell,the number of small mass fragments produced by the HCSi Mn steel shell was significantly increased with a scale parameter of 0.57 g fitted by the Weibull distribution *** fragmentation process of the HCSi Mn shell exhibited more brittle tensile fracture characteristics,with the microcrack damage zone on the outer surface being the direct cause of its high *** the one hand,the doping of alloy elements resulted in grain refinement by forming metallographic structure of tempered sorbite,so that microscopic intergranular fracture reduces the characteristic mass of the fragments;on the other hand,the distribution of alloy carbides can exert a"pinning"effect on the substrate grains,causing more initial cracks to form and propagate along the brittle carbides,further improving the shell *** the killing power radius for light armored vehicles was slightly reduced by about 6%,the dense killing radius of HCSiMn steel projectile against personnel can be significantly increased by about 26%based on theoretical *** results provided an experimental basis for high fragmentation warhead design,and to some extent,revealed the correlation mechanism between metallographic structure and shell fragmentation.

关键词： Projectile fragmentation Fragment mass distribution Fracture mode Metallographic structure Damage power