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Asymmetrically coordinated main group atomic In-S_(1)N_(3)interface sites for promoting electrochemical CO_(2)reduction

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Nano Research 2024年第6期17卷 5011-5021页

作者： Yan Gao Jinlong Ge Jingqiao Zhang Ting Cao Zhiyi Sun Wensheng Yan Yu Wang Jie Lin Wenxing Chen Zheng Liu Anhui Provincial Engineering Laboratory of Silicon-based Materials Bengbu UniversityBengbu 233030China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China SEPA Key Laboratory of Eco-Industry Chinese Research Academy of Environmental SciencesBeijing 100012China Ningbo institute of Materials Technology and Engineering Chinese Academy of ScienceNingbo 315201China Energy&Catalysis Center School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China Shanghai Synchrotron Radiation Facilities Shanghai Institute of Applied PhysicsChinese Academy of ScienceShanghai 201204China

Designing catalysts with highly active,selectivity,and stability for electrocatalytic CO_(2)to formate is currently a severe ***,we developed an electronic structure engineering on carbon nano frameworks embedded with nitrogen and sulfur asymmetrically dual-coordinated indium active sites toward the efficient electrocatalytic CO_(2)reduction *** expected,atomically dispersed In-based catalysts with In-S_(1)N_(3)atomic interface with asymmetrically coordinated exhibited high efficiency for CO_(2)reduction reaction(CO_(2)RR)to *** achieved a maximum Faradaic efficiency(FE)of 94.3%towards formate generation at−0.8 V *** hydrogen electrode(RHE),outperforming that of catalysts with In-S2N2 and In-N4 atomic *** at a potential of−1.10 V ***,In-S_(1)N_(3)achieves an impressive Faradaic efficiency of 93.7%in flow *** catalytic performance of In-S_(1)N_(3)sites was confirmed to be enhanced through in-situ X-ray absorption near-edge structure(XANES)measurements under electrochemical *** discovery provides the guidance for performance regulation of main group metal catalysts toward CO_(2)RR at atomic scale.

关键词： indium single-site catalyst main group metal asymmetrical coordination CO_(2)reduction reaction structure-activity relationship

A comparison of statistical learning of naturalistic textures between DCNNs and the human visual hierarchy

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Science China(Technological Sciences) 2024年第8期67卷 2310-2318页

作者： LU XinCheng YUAN ZiQi ZHANG YiChi AI HaiLin CHENG SiYuan GE YiRan FANG Fang CHEN NiHong Department of Psychological and Cognitive Sciences Tsinghua UniversityBeijing 100084China IDG/McGovern institute for Brain Research Tsinghua UniversityBeijing 100084China Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health Peking UniversityBeijing 100871China Key Laboratory of Machine Perception(Ministry of Education) Peking UniversityBeijing 100871China Peking-Tsinghua Center for Life Sciences Peking UniversityBeijing 100871China IDG/McGovern institute for Brain Research Peking UniversityBeijing 100871China State Key Laboratory of Brain and Cognitive Science Institute of PsychologyChinese Academy of SciencesBeijing 100101China

The visual system continuously adapts to the statistical properties of the environment. Existing evidence shows a close resemblance between deep convolutional neural networks(CNNs) and primate visual stream in neural selectivity to naturalistic textures above the primary visual processing stage. This study delves into the mechanisms of perceptual learning in CNNs,focusing on how they assimilate the high-order statistics of natural textures. Our results show that a CNN model achieves a similar performance improvement as humans, as manifested in the learning pattern across different types of high-order image statistics. While L2 was the first stage exhibiting texture selectivity, we found that stages beyond L2 were critically involved in learning. The significant contribution of L4 to learning was manifested both in the modulations of texture-selective responses and in the consequences of training with frozen connection weights. Our findings highlight learning-dependent plasticity in the mid-to-high-level areas of the visual hierarchy. This research introduces an AI-inspired approach for studying learning-induced cortical plasticity, utilizing DCNNs as an experimental framework to formulate testable predictions for empirical brain studies.

关键词： CNN perceptual learning naturalistic texture psychophysics

A polynomial resultant approach to algebraic constructions of extremal graphs

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Science China Mathematics 2024年

作者： Tao Zhang Zixiang Xu Gennian Ge institute of Mathematics and Interdisciplinary Sciences Xidian University School of Mathematical Sciences Capital Normal University

The Turan problem asks for the largest number of edges ex（n, H） in an n-vertex graph not containing a fixed forbidden subgraph H, which is one of the most important problems in extremal graph theory. However,the order of magnitude of ex（n, H） for bipartite graphs is known only in a handful of cases. In particular,giving explicit constructions of extremal graphs is very challenging in this field. In this paper, we develop a polynomial resultant approach to the algebraic construction of explicit extremal graphs, which can efficiently decide whether a specified structure exists. A key insight in our approach is the multipolynomial resultant, which is a fundamental tool of computational algebraic geometry. Our main results include the matched lower bounds on the Turan number of 1-subdivision of K3,t1and the linear Turan number of the Berge theta hypergraphΘ3B,t2, where t1= 25 and t2= 217. Moreover, the constant t1 improves the random algebraic construction of Bukh and Conlon（2018） and makes the known estimation better on the smallest value of t1 concerning a problem posed by Conlon et al.（2021） by reducing the value from a magnitude of 1056 to the number 25, while the constant t2improves a result of He and Tait（2019）.

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Study on the Impact of Imbalance between Transmission Lines on Crosstalk: a Novel Perspective of Displacement Current

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Chinese Journal of Electronics 2024年

作者： Xiaozhu LU Lingnan SONG Hui XU Donglin SU School of Electronics and Information Engineering Beihang University Research institute for Frontier Science Beihang University

This paper systematically studies the impact of imbalances between adjacent lines and effects on crosstalk. A novel perspective of displacement current is introduced to analyze and explain the simulated observations. The imbalances caused by coupling between single-single, single-differential, and differential-differential lines are studied and analyzed by considering the near-field coupling through the generated displacement currents. Measurements are conducted for various cases of coupled adjacent lines. An equivalent model considering the variation of displacement current with geometrical parameters is also proposed, and the corresponding coupling coefficients are extracted based on simulations to characterize the impact of imbalances. The methods and results presented in this paper provide useful guidelines for designing high-speed circuit layouts with closely spaced transmission lines.

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Pump pulse characteristics of quasi-continuous-wave diode-side-pumped Nd:YAG laser

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Chinese Physics B 2022年第5期31卷 355-359页

作者： Zexin Song Qi Bian Yu Shen Keling Gong Nan Zong Qingshuang Zong Yong Bo Qinjun Peng Key Laboratory of Solid State Laser Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Key Laboratory of Function Crystal and Laser Technology Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China Southwest institute of technical Physics Chengdu 610041China

The influence of pumping laser pulse on the property of quasi-continuous-wave(QCW)diode-side-pumped Nd:YAG laser is investigated theoretically and *** remaining a fixed duty cycle,the average output power increases,and the corresponding thermal focal length shorten with the increase of the pump pulse duration,which attributes to the decrease of the ratio of pulse buildup time to the pulse *** a pump power of 146 W,the laser output power changes from 65.1 W to 81.2 W when the pulse duration is adjusted from 150μs to 1000μs,confirming a significant enhancement of 24.7%.A laser rate equation model incorporating the amplified spontaneous emission is also utilized and numerically solved,and the simulated results agree well with the experimental data.

关键词： pump pulse duration diode-side-pumped pulsed Nd:YAG laser laser rate equation amplified spontaneous emission

An Improved Z-buffer Accelerated PO Method for EM Scattering from Electrically Large Targets

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Chinese Journal of Electronics 2024年

作者： Jiangfei BAI Shunchuan YANG Donglin SU School of Electronics and Information Engineering Beihang University Research institute for Frontier Science Beihang University

The physical optical(PO) method is widely used to solve the electromagnetic scattering problems involved electrically large structures, in which each surface element is required to determine whether it is blocked by others. It may suffer from the computational efficiency issue through elementwise shadowing testing. In this paper, an efficient Z-buffer based shadowing testing method is proposed to accelerate this procedure. In the proposed method,all triangular facets are first mapped to a grid plane as the Z-buffer method, and for each grid cell, all projected triangles intersecting it are recorded. Then, rigorous shadowing testing is made for all facets recorded in the grid where the centroid of each triangle is projected. It can avoid a large number of redundant operations for pairs of triangles with no occlusion relation, which lead to the same accuracy as the traditional rigorous shadowing testing method with significantly efficiency improvement. Four numerical examples are carried out to validate its accuracy and efficiency.

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Understanding Why People Complain: Using Spatial Embeddedness to Explore Residents' Satisfaction in China's Danwei Neighborhood Renovation

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China City Planning Review 2024年第3期33卷 51-61页

作者： Li Yue Zhou Peiling Li Min School of Architecture Chang'an University Department of Urban and Rural Planning Harbin Institute of Technology Shenzhen

Against the backdrop of China's socio-economic transition, there is a growing imperative to examine neighborhood renovation initiatives in addressing the emerging needs of residents. Developing Granovetter's classic work on embeddedness, this paper proposes a conceptual framework of spatial embeddedness to understand changes in the physical space brought about by neighborhood renovation, in order to explore how it affects residents' satisfaction in a dynamic temporal and spatial process. It presents whether and why residents' real feelings produced from their interaction with neighborhood renovation are(un)different, and how their feelings are shaped based on six months of fieldwork in a danwei neighborhood in Xi'an, China. The paper conceptualizes the relationship between the neighborhood space and embeddedness by adopting spatial embeddedness to capture the interplay of temporal, spatial, and social factors in the process of danwei neighborhood renovation. This framework not only integrates multiple perspectives and scales, but also reflects different levels of residents' satisfaction, trying to establish a connection between the abstract space and the renovation space. It suggests that spatial embeddedness should be considered as a response to the negative social impacts resulting from changes in the physical space in neighborhood renovation.

关键词： spatial embeddedness danwei neighborhood renovation residents'satisfaction abstract space China

Energy consumption mechanism simulation and experimental study of reciprocating vibration for Chinese wolfberry picking

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International Journal of Agricultural and Biological Engineering 2024年第4期17卷 146-155页

作者： Song Mei Dunbing Tang Zhigang Shi Zhiyu Song Cheng Shen College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Nanjing institute of Agricultural Mechanization Ministry of Agriculture and Rural AffairsNanjing 210014China institute of Chinese Wolfberry Science Ningxia Academy of Agriculture and Forestry SciencesYinchuan 750002China

In order to find out the matching principle of excitation force and energy consumption of reciprocating vibrating Chinese wolfberry picking device,the energy consumption mechanism of reciprocating vibrating Chinese wolfberry picking device is *** to the structural characteristics and operating principle of the picking device,the no-load and load movement and force characteristics of the crank bearing and vibrating component are analyzed,and the theoretical model of energy consumption of the reciprocating vibration picking device is jointly constructed,and the simulation analysis is carried *** results show that the vibrating component and load mass have a significant influence on torque,the load air resistance phase has a significant effect on torque,and the load air resistance and friction coefficient have no significant influence on ***,by building an AC servo motor torque detection system and a torque sensing detection system,verification experiments are carried out,the maximum torque of the preset system is 1.3 N∙m,the rated power is 400 W,the motor frequency is 20 Hz,the amplitude is 15 mm,and the total mass of the vibrating component is 0.143 *** results show that,the no-load operation,the change trend of detected torque is consistent with simulation,the torque model is verified to be *** maximum torque of simulation and detection are 0.52 N∙m and 0.57 N∙m respectively,and the error between test and simulation is 9.6%.For load operation,the maximum torque of five groups of branch loads of 20 g,60 g,100 g,140 g,180 g and 220 g are detected to be 0.73 N∙m,0.74 N∙m,0.75 N∙m,0.82 N∙m and 0.83 N∙m,respectively,and the relationship model between load and torque is obtained by *** research results can provide a theoretical basis which can configure a suitable motor in the reciprocating vibration Chinese wolfberry picking device with a certain load limit.

关键词： Chinese wolfberry branches vibration component load torque power

Target localization for deep-sea vertical line array in the direct-arrival zone using deconvolution method

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Chinese Journal of Acoustics 2024年第3期43卷 290-310页

作者： LYU Jiahui LUO Zailei SHEN Tongsheng National Innovation institute of Defense Technology Advanced Interdisciplinary Technology Research CenterBeijing100071

The conventional method of deep-sea acoustic source localization usually uses the multi-path arrival information of the acoustic source signals received by hydrophone arrays to match with the simulation results to achieve *** at the problem that it is difficult to extract the similar multi-path arrival angle directly by the conventional method,a deconvolution positioning method for deep-sea vertical array underwater target is *** using this method,not only the adaptive iterative frequency-domain Richardson-Lucy algorithm is used to directly estimate the multipath angle of arrival of deep-sea acoustic targets,but also the ranging and depth fixing are realized by matching the sound field angle of arrival feature *** and experimental results show that this positioning method has higher localization accuracy and applicability than the conventional method,and has high computational efficiency.

关键词： method angle template