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Optimization of inter-seasonal nitrogen allocation increases yield and resource-use efficiency in a water-limited wheat-maize cropping system in the North China Plain

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The Crop Journal 2024年第3期12卷 907-914页

作者： Xiaonan Zhou Chenghang du Haoran li zhencai Sun Yifei Chen Zhiqiang Gao Zhigan Zhao Yinghua Zhang Zhimin Wang Ying liu College of Agronomy and Biotechnology China Agricultural UniversityBeijing 100193China College of Information and Electrical Engineering China Agricultural UniversityBeijing 100193China Ministerial and Provincial Co-Innovation Centre for Endemic Crops Production with High-Quality and Efficiency in Loess Plateau Taigu 030801ShanxiChina

Winter wheat–summer maize cropping system in the North China Plain often experiences droughtinduced yield reduction in the wheat season and rainwater and nitrogen(N)fertilizer losses in the maize *** study aimed to identify an optimal interseasonal water-and N-management strategy to alleviate these *** ratios of allocation of 360 kg N ha^(-1)between the wheat and maize seasons under one-time presowing root-zone irrigation(W0)and additional jointing and anthesis irrigation(W2)in wheat and one irrigation after maize sowing were set as follows:N1(120:240),N2(180:180),N3(240:120)and N4(300:60).The results showed that under W0,the N3 treatment produced the highest annual yield,crop water productivity(WPC),and nitrogen partial factor productivity(PFPN).Increased N allocation in wheat under W0 improved wheat yield without affecting maize yield,as surplus nitrate after wheat harvest was retained in the topsoil layers and available for the subsequent *** W2,annual yield was largest in the N2 *** risk of nitrate leaching increased in W2 when N application rate in wheat exceeded that of the N2 treatment,especially in the wet *** to W2N2,the W0N3 maintained 95.2%grain yield over two *** WPCwas higher in the W0 treatment than in the W2 ***,following limited total N rate,an appropriate fertilizer N transfer from maize to wheat season had the potential of a“triple win”for high annual yield,WPCand PFPN in a water-limited wheat–maize cropping system.

关键词： Cropping system Water-saving irrigation North China Plain Nitrogen optimization Sustainable intensification

Delving into the dissimilarities in electrochemical performance and underlying mechanisms for sodium and potassium ion storage in N-doped carbon-encapsulated metallic Cu_(2)Se nanocubes

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Journal of Energy Chemistry 2024年第8期95卷 336-347,I0008页

作者： Xinyu Wang Yanan Xu Xiaofeng liu Lei tan Huaiqiang Gu Xin du Dan li College of Chemistry Zhengzhou UniversityZhengzhou 450001HenanChina Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou 450001HenanChina Institute of Theoretical Physics Lanzhou UniversityLanzhou 730000GansuChina School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000GansuChina Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071China State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources College of ChemistryXinjiang UniversityUrumqi 830046XinjiangChina

The large volumetric variations experienced by metal selenides within conversion reaction result in inferior rate capability and cycling stability,ultimately hindering the achievement of superior electrochemical ***,metallic Cu_(2)Se encapsulated with N-doped carbon(Cu_(2)Se@NC)was prepared using Cu_(2)O nanocubes as templates through a combination of dopamine polymerization and hightemperature *** unique nanocubic structure and uniform N-doped carbon coating could shorten the ion transport distance,accelerate electron/charge diffusion,and suppress volume variation,ultimately ensuring Cu_(2)Se@NC with excellent electrochemical performance in sodium ion batteries(SIBs)and potassium ion batteries(PIBs).The composite exhibited excellent rate performance(187.7 mA h g^(-1)at 50 A g^(-1)in SIBs and 179.4 mA h g^(-1)at 5 A g^(-1)in PIBs)and cyclic stability(246,8 mA h g^(-1)at 10 A g^(-1)in SIBs over 2500 cycles).The reaction mechanism of intercalation combined with conversion in both SIBs and PIBs was disclosed by in situ X-ray diffraction(XRD)and ex situ transmission electron microscope(TEM).In particular,the final products in PIBs of K_(2)Se and K_(2)Se_(3)species were determined after discharging,which is different from that in SIBs with the final species of Na_(2)*** density functional theory calculation showed that carbon induces strong coupling and charge interactions with Cu_(2)Se,leading to the introduction of built-in electric field on heterojunction to improve electron ***,the theoretical calculations discovered that the underlying cause for the relatively superior rate capability in SIBs to that in PIBs is the agile Na~+diffusion with low energy barrier and moderate adsorption *** findings offer theoretical support for in-depth understanding of the performance differences of Cu-based materials in different ion storage systems.

关键词： Cu_(2)Se nanocubes DFT calculations Ion storage mechanism Potassium ion batteries Sodium ion batteries

Improving pixel-based regional landslide susceptibility mapping

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Geoscience Frontiers 2024年第4期15卷 196-216页

作者： Xin Wei Paolo Gardoni Lulu Zhang lin tan Dongsheng liu Chunlan du Hai li State Key Laboratory of Ocean Engineering Department of Civil EngineeringShanghai Jiao Tong University800 Dongchuan RoadShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration(CISSE) Shanghai 200240China Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure Shanghai 200240China Department of Civil and Environmental Engineering MAE Center:Creating a Multi-Hazard Approach to EngineeringUniversity of Illinois at Urbana-Champaign205 N.Mathews AveUrbana IL 61801United States Chongqing Bureau of Geology and Minerals Exploration Chongqing 401121China Hydrogeology&Engineering Team 208 Chongqing Bureau of Geology and Minerals Exploration(Chongqing Reconnaissance and Design Academy of Geological Disasters Prevention and Treatment Engineering)Chongqing 400700China

Regional landslide susceptibility mapping(LSM)is essential for risk *** deep learning algorithms are increasingly used in LSM,their extensive parameters and scarce labels(limited landslide records)pose training *** contrast,classical statistical algorithms,with typically fewer parameters,are less likely to overfit,easier to train,and offer greater ***,integrating physics-based and data-driven approaches can potentially improve *** paper makes several contributions to enhance the practicality,interpretability,and cross-regional generalization ability of regional LSM models:(1)Two new hybrid models,composed of data-driven and physics-based modules,are proposed and *** ModelⅠcombines the infinite slope stability analysis(ISSA)with logistic regression,a classical statistical *** ModelⅡintegrates ISSA with a convolutional neural network,a representative of deep learning *** physics-based module constructs a new explanatory factor with higher nonlinearity and reduces prediction uncertainty caused by incomplete landslide inventory by pre-selecting non-landslide *** data-driven module captures the rela-tion between explanatory factors and landslide inventory.(2)A step-wise deletion process is proposed to assess the importance of explanatory factors and identify the minimum necessary factors required to maintain satisfactory model performance.(3)Single-pixel and local-area samples are compared to understand the effect of pixel spatial neighborhood.(4)The impact of nonlinearity in data-driven algorithms on hybrid model performance is *** landslide-prone regions in the Three Gorges Reservoir,China,are used as the study *** results show that,in the testing region,by using local-area samples to account for pixel spatial neighborhoods,Hybrid ModelⅠachieves roughly a 4.2%increase in the ***,models with 30 m resolution land-cover data surpass those using 1

关键词： Landslide susceptibility mapping Logistic regression Convolutional neural network Hybrid model Interpretability Cross-regional generalization

Design of digital calibration based on variable step size of sub-binary SAR ADC

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The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 62-71页

作者： liu Wei Zhao yanke Shang Shiguang School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China

Addressing the impact of capacitor mismatch on the conversion accuracy of successive approximation register analog-to-digital converter(SAR ADC),a 12-bit 1 MS/s sub-binary SAR ADC designed using variable step size digital calibration was *** least mean square(LMS)calibration algorithm was employed with a ramp signal used as the calibration *** errors,extracted under injected disturbances,underwent iterative training to optimize weight *** address the trade-off between conversion accuracy and speed caused by a fixed step size,a novel variable step size algorithm tailored for SAR ADC calibration was *** core circuit and layout of the SAR ADC were implemented using the Taiwan Semiconductor Manufacturing Company(TSMC)0.35μm complementary metal-oxide-semiconductor(CMOS)commercial *** of the SAR ADC calibration algorithm was conducted using Simulink,demonstrating quick convergence and meeting conversion accuracy requirements compared to fixed step size *** results indicated that the convergence speed of the LMS digital calibration algorithm with variable step size was approximately eight times faster than that with a fixed step size,also yielding a lower mean square error(MSE).After calibration,the simulation results for the SAR ADC exhibited an effective number of bit(ENOB)of 11.79 bit and a signal-to-noise and distortion ratio(SNDR)of 72.72 dB,signifying a notable enhancement in the SAR ADC performance.

关键词： successive approximation register analog-to-digital converter(SAR ADC) variable step size digital calibration disturbance technique

Visible-light-Mediated Photocatalyst-Free Hydroacylation of Azodicarboxylic Acid Derivatives with 4-Acyl-1,4-dihydropyridines

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Chinese Journal of Chemistry 2024年第11期42卷 1230-1236页

作者： li liu Jing Wang Xiaoying Feng Kun Xu Wei liu Xia Peng Hongguang du Jiajing tan Department of Organic Chemistry College of ChemistryBeijing University of Chemical TechnologyBeijing100029 China Sinopec Beijing Research Institute of Chemical Industry Beijing100013 China Faculty of Environment and life Beijing University of TechnologyBeijing100124 China

A visible-light-enabled,photocatalyst-free hydroacylation reaction of azodicarboxylic acid derivatives was *** radical conjugate addition(RCA)protocol relied on the dual role of 4-acyl-1,4-dihydropyridine(acyl-DHP)reagents that besides being as radical reservoirs,they also enabled the conversion of radical adducts to anion intermediates via ***“catalyst-oxidant-additive free”conditions,a wide range of structurally different acyl hydrazide products were readily obtained in 56%—99%*** utility of this transformation was further demonstrated by the scale-up synthesis and downstream derivatization.

关键词： Azo compounds Radicals Acylation 4-Acyl-1,4-dihydropyridine Photochemistry

Sequential Propagation of Chaos for Mean-Field BSDE Systems

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Chinese Annals of Mathematics,Series B 2024年第1期45卷 11-40页

作者： Xiaochen li Kai du Shanghai Center for Mathematical Sciences Fudan UniversityShanghai 200433China. Shanghai Artificial Intelligence Laboratory 701 Yunjin RoadShanghai 200433China

A new class of backward particle systems with sequential interaction is proposed to approximate the mean-field backward stochastic differential *** is proven that the weighted empirical measure of this particle system converges to the law of the McKean-Vlasov system as the number of particles *** on the Wasserstein met-ric,quantitative propagation of chaos results are obtained for both linear and quadratic growth ***,numerical experiments are conducted to validate our theoretical results.

关键词： Backward propagation of chaos Particle system Sequential interaction McKean-Vlasov BSDE Convergence rate

Higher-order expansions of powered extremes of logarithmic general error distribution

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 47-54页

作者： tan Xiao-feng li li-hui School of Mathematics and Statistics Southwest UniversityChongqing 400715China

In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥***-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of normalizing *** is shown that M_(n)^(p),when v=1,converges to the Frechet extreme value distribution at the rate of 1/n,and if v>1 then M_(n)^(p)converges to the Gumbel extreme value distribution at the rate of(loglogn)^(2)=(log n)^(1-1/v).

关键词： logarithmic general error distribution convergence rate higher-order expansion powered ex-treme

An Improved Method for Approximating the Infinite-Horizon Value Function of the Discrete-Time Switched LQR Problem

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Journal of Systems Science & Complexity 2024年第1期37卷 22-39页

作者： HOU tan li Yuanlong liN Zongli Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of System Control and Information Processing Ministry of Education of ChinaShanghai 200240China Shanghai Engineering Research Center of Intelligent Control and Management Shanghai 200240China Charles L.Brown Department of Electrical and Computer Engineering University of VirginiaCharlottesvilleVA 22904-4743USA

This paper considers the problem of approximating the infinite-horizon value function of the discrete-time switched LQR *** particular,the authors propose a new value iteration method to generate a sequence of monotonically decreasing functions that converges exponentially to the value *** method facilitates us to use coarse approximations resulting from faster but less accurate algorithms for further value iteration,and thus,the proposed approach is capable of achieving a better approximation for a given computation time compared with the existing *** numerical examples are presented in this paper to illustrate the effectiveness of the proposed method.

关键词： Optimal control switched linear systems switched LQR problem.

Cathodic corrosion as a facile and universal method for scalable preparation of powdery single atom electrocatalysts

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Nano Research 2024年第6期17卷 4943-4950页

作者： Rui li Xiayan Yan Meng liu Qingkai Zhao Jie du Xinxin tan Jingwen Ba Rongguang Zeng Wenhua Luo Jingsong Xu Institute of Materials China Academy of Engineering PhysicsJiangyou 621907China Science and Technology on Surface Physics and Chemistry Laboratory Jiangyou 621908China

Top-down strategy has been widely applied for synthesis of metal single atom catalysts(SACs)via converting metal nanoparticles or bulk metals into atomically dispersed ***,we report a simple electrochemical atomic migration strategy for top-down synthesis of SACs via a facile cathodic corrosion process without involving high temperature or harsh *** of metal nanoparticles on cathode are firstly disbanded under high negative voltage,and emitted into the electrolyte in the form of atomic metal anions in Zintl *** escaped atomically dispersed metal species are then oxidized by water molecules and captured by the defects on the pre-added nitrogen doped carbon carriers in the *** cathodic corrosion strategy is confirmed to be suitable for scalable synthesis of kinds of metal SACs(e.g.,Pt,Pd,and Ir)on doped carbon ***,the as-prepared nitrogen doped carbon powder supported Pt SACs exhibit superior catalytic activity toward hydrogen evolution reaction(HER)with a low overpotential of 0.024 V at 10 mA·cm^(−2)and a low Tafel slope of 29.7 mV·dec^(−1)as well as a long-term durability.

关键词： cathodic corrosion top-down strategy powdery single atom catalysts hydrogen evolution reaction scalable synthesis