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Strong metal-support interactions between highly dispersed Cu^(+) species and ceria via mix-MOF pyrolysis toward promoted water-gas shift reaction

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Journal of Energy Chemistry 2024年第4期91卷 475-483页

作者： Xiao-chen Sun Xing-Chi Li Ze-Wei Xie chen-Yue Yuan De-Jiu Wang Qian Zhang Xiao-Yu guo Hao Dong Hai-Chao {3. Ya-Wen Zhang beijing National Laboratory for Molecular sciences(BNLMS) State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic ChemistryCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China beijing National Laboratory for Molecular sciences(BNLMS) College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China beijing National Laboratory for Molecular sciences(BNLMS) State Key Laboratory for Structural Chemistry of Stable and Unstable SpeciesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

The modulation of metal-support interfacial interaction is significant but challenging in the design of high-efficiency and high-stability supported ***,we report a synthetic strategy to upgrade Cu-CeO_(2)interfacial interaction by the pyrolysis of mixed metal-organic framework(MOF)*** obtained highly dispersed Cu/CeO_(2)-MOF catalyst via this strategy was used to catalyze water-gas shift reaction(WGSR),which exhibited high activity of 40.5μmolCOgcat^(-1).s^(-1)at 3.0℃and high stability of about 120 *** on comprehensive studies of electronic structure,pyrolysis strategy has significant effect on enhancing metal-support interaction and then stabilizing interfacial Cu^(+)species under reaction *** Cu^(+)species and generated oxygen vacancies over Cu/CeO_(2)-MOF catalyst played a key role in CO molecule activation and H2O molecule dissociation,*** collaborated closely and then promoted WGSR catalytic performance in comparison with traditio nal supported *** study shall offer a robust approach to harvest highly dispersed catalysts with finely-tuned metal-support interactions for stabilizing the most interfacial active metal species in diverse heterogeneous catalytic reactions.

关键词： Cu-based catalyst MOF derivative Water-gas shift reaction Metal-support interaction

Source Enrichment Control on the Scale of Magmatic-Hydrothermal W-Sn Mineralization:Insights from Triassic and Jurassic Magma Reservoirs in the Continental Crust,Xitian,South china

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 132-149页

作者： guo Chunli Simon AWILDE Coralie SIEGEL chen Zhenyu WU Shichong MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China SinoProbe Laboratory Chinese Academy of Geological SciencesBeijing 100094China school of earth and Planetary sciences Curtin UniversityPerth 6845Australia Discovery Program Mineral ResourcesCommonwealth Scientific and Industrial Research OrganisationAustralian Resources Research CentrePerth 6151Australia No.416 Geological Group Hunan Bureau of Mineral Exploration and DevelopmentZhuzhouHunan 412007China

There are two factors,source composition and magmatic differentiation,potentially controlling W-Sn *** one is more important is widely debated and may need to be determined for each individual *** Xitian granite batholith located in South china is a natural laboratory for investigating the above *** consists essentially of two separate components,formed in the Triassic at ca.226 Ma and Jurassic at ca.152 Ma,*** Triassic and Jurassic rocks are both composed of porphyritic and fine-grained *** latter resulted from highlydifferentiated porphyritic ones but they have similar textural characteristics and mineral assemblages,indicating that they reached a similar degree of crystal *** both fine-grained phases are highly differentiated with elevated rare metal contents,economic W–Sn mineralization is rare in the Triassic granitoids and this can be attributed to less fertile source materials than their Jurassic counterparts,with a slightly more enriched isotopic signature and whole-rockεNd(226 Ma)of−10.4 to−9.2(2σ=0.2)compared withεNd(152 Ma)of−9.2 to−8.2(2σ=0.2)for the Jurassic *** initial W-Sn enrichment was derived from the metasedimentary rocks and strongly enhanced by reworking of the continental crust,culminating in the Jurassic.

关键词： W-Sn mineralization magma reservoir geometry crystal fractionation Xitian Triassic-Jurassic granitic batholith Nanling Range South china

Multiple time scale evaluation of the energy balance during the maize growing season,and a new reason for energy imbalance

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Science china earth sciences 2009年第1期52卷 108-117页

作者： guo JianXia1,2,BIAN LinGen3.& DAI YongJiu2 1 Meteorological Observation Center of china Meteorological Administration,beijing 100081,china 2 State Key Laboratory of Remote Sensing Science,school of Geography and Remote Sensing Science,beijing Normal university,beijing 100875,china 3.Chinese Academy of Meteorological sciences,beijing 100081,china Meteorological Observation Center of china Meteorological Administration Beijing China State Key Laboratory of Remote Sensing Science School of Geography and Remote Sensing Science Beijing Normal University Beijing China Chinese Academy of Meteorological sciences Beijing China

Energy imbalance is a common problem associated with the measurement of surface energy using the eddy covariance *** the evaluation of the energy balance,people usually pay more attention to the statistical result that the effective energy(the sum of sensible and latent heat) is systematically lower than the available energy(the difference of net radiation and ground heat flux).However,little attention has been paid to the existence of the reversed situation when the effective energy is larger than the available energy or their contribution to the overall energy closure *** this paper,based on the analysis of the energy balance on multiple time scales across the maize growth season,we conclude that the non-synchronization of energy components is the main reason for the existence of the reversed *** shifting the phase of the effective energy components half an hour ahead,the rates of energy closure over all time scales are improved and dramatically reduce the number of the half-hourly samples when the energy ratio exceeds 1 or is below *** to the characteristics of the energy distribution and transformation over multiple time scales,latent heat is always the main type of energy cost,and the residual of the energy balance increases with the growth of the maize plant surpassing the sensible heat for seventy *** is suggested that the heat storage and photosynthetic energy play an important role in the energy balance during the growing period of maize.

关键词： maize energy balance multiple time scale energy hysteresis

The Roadmap of 2D Materials and Devices Toward Chips

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Nano-Micro Letters 2024年第6期16卷 343-438页

作者： Anhan liu Xiaowei Zhang Ziyu liu Yuning Li Xueyang Peng Xin Li Yue Qin chen Hu Yanqing Qiu Han Jiang Yang Wang Yifan Li Jun Tang Jun liu Hao guo Tao Deng Songang Peng He Tian Tian‑Ling Ren school of Integrated Circuits and beijing National Research Center for Information Science and Technology(BNRist) Tsinghua UniversityBeijing 100049People’s Republic of China school of Microelectronics Fudan UniversityShanghai 200433People’s Republic of China State Key Laboratory of Dynamic Measurement Technology Shanxi Province Key Laboratory of Quantum Sensing and Precision MeasurementNorth University of ChinaTaiyuan 030051People’s Republic of China High‑Frequency High‑Voltage Device and Integrated Circuits R&D Center Institute of MicroelectronicsChinese Academy of SciencesBeijing 100029People’s Republic of China school of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044People’s Republic of China school of Integrated Circuits University of Chinese Academy of SciencesBeijing 100049People’s Republic of China IMECAS-HKUST-Joint Laboratory of Microelectronics Beijing 100029People’s Republic of China

Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s ***-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation ***,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given *** 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are ***,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are ***,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked.

关键词： Two-dimensional materials Roadmap Integrated circuits Post-Moore era

Identification and removal of block ambiguities in sea surface wind field with scatterometers

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Science china earth sciences 2009年第2期52卷 242-249页

作者： chen KeHai1,2, XIE XueTong3.& FANG Yu4 1 South china Sea Institute of Oceanology, Chinese Academy of sciences, Guangzhou 5103.1, china 2 Graduate university of Chinese Academy of sciences, beijing 100049, china 3.school of Electronic Science and Engineering, National university of Defense Technology, Changsha 410073. china 4 The Institute of Remote Sensing and GIS, Peking university, beijing 100871, china South china Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou China Graduate university of Chinese Academy of sciences Beijing China school of Electronic Science and Engineering National University of Defense Technology Changsha China The Institute of Remote Sensing and GIS Peking University Beijing China

The solution of the current wind retrieval algorithm for scatterometers has several wind vector ambi-guities, due to the bi-harmonic relationship between normalized backscattering cross section and the relative wind direction and the existence of the measurement error. In order to remove the ambiguities for a unique wind field, a circular median filter approach (CMF) is usually adopted. But under the con-dition for clustering distribution of the false ambiguities in some local areas, the CMF fails and thus engenders block ambiguities, which degrade the precision of the retrieved wind field. For such a situation, a technique of identification and removal of the block ambiguities is presented to further optimize the retrieved wind field after CMF. It is demonstrated in experiment that this technique can identify and remove most of the block ambiguities.

关键词： scatterometer block ambiguity identification and removal

The binding and structural basis of fox ACE2 to RBDs from different sarbecoviruses

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Virologica Sinica 2024年第4期39卷 609-618页

作者： Junsen chen Junqing Sun Zepeng Xu Linjie Li Xinrui Kang Chunliang Luo Qi Wang Xueyang guo Yan Li Kefang liu Ying Wu State Key Laboratory of Virology and Hubei Province Key Laboratory of Allergy and Immunology Institute of Medical VirologyTaiKang Medical School(School of Basic Medical Sciences)Wuhan UniversityWuhan430071China CAS Key Laboratory of Pathogen Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing100101China beijing Life Science Academy Beijing102209China Faculty of Health sciences University of MacaoMacaoSAR999078China

Foxes are susceptible to SARS-CoV-2 in laboratory settings,and there have also been reports of natural infections of both SARS-CoV and SARS-CoV-2 in *** this study,we assessed the binding capacities of fox ACE2 to important sarbecoviruses,including SARS-CoV,SARS-CoV-2,and animal-origin SARS-CoV-2 related *** findings demonstrated that fox ACE2 exhibits broad binding capabilities to receptor-binding domains(RBDs)of *** further determined the cryo-EM structures of fox ACE2 complexed with RBDs of SARS-CoV,SARS-CoV-2 prototype(PT),and Omicron *** structural analysis,we identified that the K417 mutation can weaken the ability of SARS-CoV-2 sub-variants to bind to fox ACE2,thereby reducing the susceptibility of foxes to SARS-CoV-2 *** addition,the Y498 residue in the SARS-CoV RBD plays a crucial role in forming a vital cation-πinteraction with K3.3.in the fox ACE2 *** interaction is the primary determinant for the higher affinity of the SARS-CoV RBD compared to that of the SARS-CoV-2 PT *** results indicate that foxes serve as potential hosts for numerous sarbecoviruses,highlighting the critical importance of surveillance efforts.

关键词： Sarbecoviruses SARS-CoV SARS-CoV-2 Fox ACE2 Omicron Cryo-EM structure

Very long wave infrared quantum cascade detector based on modular band structure

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CHINESE OPTICS LETTERS 2024年第8期22卷 083701-083701页

作者： guo, Kai chen, Yu Zhu, Yixuan Li, Kun Zhai, Shenqiang liu, Fengqi Tang, Jilong Wang, Xiaohua Wei, Zhipeng liu, Junqi Changchun Univ Sci & Technol Sch Phys State Key Lab High Power Semicond Lasers Changchun 130022 Peoples R China Chinese Acad Sci Key Lab Semicond Mat Sci Inst Semicond Beijing 100083 Peoples R China Univ Chinese Acad Sci Ctr Mat Sci & Optoelect Technol Beijing 101408 Peoples R China

The optoelectronic performance of quantum cascade detectors (QCDs) is highly sensitive to the design of the energy level structure, leading to the inability of a single structure to achieve broad wavelength tuning. To address this issue, we propose and demonstrate a modular concept for very long wave infrared (VLWIR) QCDs based on a miniband diagonal transition scheme. The modular design makes the wavelength tuning only need to be adjusted for the absorption quantum well module rather than for the whole active region. Theoretical simulation shows that the wavelength tuning range is 3..6 meV (similar to 14-3. similar to 14-3. mu m). To prove the feasibility of the scheme, three samples with different absorption well widths were fabricated and characterized. At 10 K, the response wavelengths of the three QCDs are 14, 16, and 18 mu m, respectively, corresponding to responsivities and detectivities exceeding 2 mA/W and 1 x 1010 10 Jones.

关键词： quantum cascade detector very long wave infrared modular band structure miniband diagonal transition wide tuning range

Flexible assistance strategy of lower limb rehabilitation exoskeleton based on admittance model

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Science china(Technological sciences) 2024年第3期67卷 823-834页

作者： KOU JianGe WANG YiXuan chen ZhenLei SHI Yan guo Qing XU Meng school of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China school of Aeronautics and Astronautics University of Electronic Science and Technology of ChinaChengdu 611731China Department of Musculoskeletal Tumor Senior Department of Orthopedicsthe Fourth Medical Centerof PLA GeneralHospitalBeijing 100853China

Exercise training based on exoskeleton is an effective rehabilitation method for stroke patients. However, some rehabilitation exoskeletons still have poor wearable performance and obvious human-robot impedance during training, which easily cause secondary injuries to the patients. In this study, a variable admittance control strategy is proposed to improve the operator's wearable comfort, which can adapt to different operators by regulating admittance parameters. The admittance controller has two feedback loops: the position inner-loop and the admittance outer-loop. Meanwhile, the exoskeleton Lagrange model is constructed with unknown friction disturbance. By using Lyapunov technique and backstepping with state observer, the joint position error of exoskeleton is convergence into a zero neighborhood. The effectiveness of the proposed admittance controller is verified by both simulation and experiment. The tracking error of hip and knee joint is less than 4 degrees while the human-robot interaction torque is constrained in a tolerable range of the operator.

关键词： human-robot interaction exoskeleton backstepping admittance control

Cone-beam computed tomography noise reduction method based on U-Net with convolutional block attention module in proton therapy

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Nuclear Science and Techniques 2024年第7期35卷 89-100页

作者： Xing-Yue Ruan Xiu-Fang Li Meng-Ya guo Mei chen Ming Lv Rui Li Zhi-Ling chen Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai201800China university of Chinese Academy of sciences Beijing100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai201210China Department of Radiation Oncology Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghai200025China Shanghai Key Laboratory of Proton therapy Shanghai201801China

Cone-beam computed tomography(CBCT) is mostly used for position verification during the treatment process. However,severe image artifacts in CBCT hinder its direct use in dose calculation and adaptive radiation therapy re-planning for proton therapy. In this study, an improved U-Net neural network named CBAM-U-Net was proposed for CBCT noise reduction in proton therapy, which is a CBCT denoised U-Net network with convolutional block attention modules. The datasets contained 20 groups of head and neck images. The CT images were registered to CBCT images as ground truth. The original CBCT denoised U-Net network, sCTU-Net, was trained for model performance comparison. The synthetic CT(SCT) images generated by CBAM-U-Net and the original sCTU-Net are called CBAM-SCT and U-Net-SCT images, respectively. The HU accuracies of the CT, CBCT, and SCT images were compared using four metrics: mean absolute error(MAE), root mean square error(RMSE), peak signal-to-noise ratio(PSNR), and structure similarity index measure(SSIM). The mean values of the MAE, RMSE, PSNR, and SSIM of CBAM-SCT images were 23.80 HU, 64.63.HU, 52.27 dB, and 0.9919, respectively,which were superior to those of the U-Net-SCT images. To evaluate dosimetric accuracy, the range accuracy was compared for a single-energy proton beam. The γ-index pass rates of a 4 cm × 4 cm scanned field and simple plan were calculated to compare the effects of the noise reduction capabilities of the original U-Net and CBAM-U-Net on the dose calculation results. CBAM-U-Net reduced noise more effectively than sCTU-Net, particularly in high-density tissues. We proposed a CBAM-U-Net model for CBCT noise reduction in proton therapy. Owing to the excellent noise reduction capabilities of CBAM-U-Net, the proposed model provided relatively explicit information regarding patient tissues. Moreover, it maybe be used in dose calculation and adaptive treatment planning in the future.

关键词： Proton therapy Cone-beam CT CBAM-U-Net γ-index