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Ultrahigh spatiotemporal resolution beam signal reconstruction with bunch phase compensation

Nuclear Science and Techniques 2024年第5期35卷 99-108页

作者： You-Ming Deng yong-Bin Leng Xing-Yi xu Jian Chen Yi-mei Zhou Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of the Chinese Academy of Sciences Beijing 100049China Shanghai Synchrotron Radiation Facility Chinese Academy of SciencesShanghai 201204China University of Science and Technology of China Hefei 230026China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

Various electromagnetic signals are excited by the beam in the acceleration and beam-diagnostic elements of a particle accelerator.It is important to obtain time-domain waveforms of these signals with high temporal resolution for research,such as the study of beam–cavity interactions and bunch-by-bunch parameter measurements.Therefore,a signal reconstruction algorithm with ultrahigh spatiotemporal resolution and bunch phase compensation based on equivalent sampling is proposed in this paper.Compared with traditional equivalent sampling,the use of phase compensation and setting the bunch signal zero-crossing point as the time reference can construct a more accurate reconstructed signal.The basic principles of the method,simulation,and experimental comparison are also introduced.Based on the beam test platform of the Shanghai Synchrotron Radiation Facility(SSRF)and the method of experimental verification,the factors that affect the reconstructed signal quality are analyzed and discussed,including the depth of the sampled data,quantization noise of analog-to-digital converter,beam transverse oscillation,and longitudinal oscillation.The results of the beam experiments show that under the user operation conditions of the SSRF,a beam excitation signal with an amplitude uncertainty of 2%can be reconstructed.

关键词： Turn-by-turn bunch phase compensation technique Equivalent sampling Signal reconstruction algorithm Ultrahigh spatiotemporal resolution SSRF

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Molecular Generation and Optimization of Molecular Properties Using a Transformer Model

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Big Data Mining and Analytics 2024年第1期7卷 142-155页

作者： Zhongyin xu Xiujuan Lei mei Ma Yi Pan School of Computer Science Shaanxi Normal UniversityXi'an 710119China Faculty of Computer Science and Control Engineering Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Generating novel molecules to satisfy specific properties is a challenging task in modern drug discovery,which requires the optimization of a specific objective based on satisfying chemical rules.Herein,we aim to optimize the properties of a specific molecule to satisfy the specific properties of the generated molecule.The Matched Molecular Pairs(MMPs),which contain the source and target molecules,are used herein,and logD and solubility are selected as the optimization properties.The main innovative work lies in the calculation related to a specific transformer from the perspective of a matrix dimension.Threshold intervals and state changes are then used to encode logD and solubility for subsequent tests.During the experiments,we screen the data based on the proportion of heavy atoms to all atoms in the groups and select 12365,1503,and 1570 MMPs as the training,validation,and test sets,respectively.Transformer models are compared with the baseline models with respect to their abilities to generate molecules with specific properties.Results show that the transformer model can accurately optimize the source molecules to satisfy specific properties.

关键词： molecular optimization transformer Matched Molecular Pairs(MMPs) logD solubility

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Anoctamin 4 defines glucose-inhibited neurons in the ventromedial hypothalamus

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Neural Regeneration Research 2024年第6期19卷 1177-1178页

作者： Longlong Tu Yanlin He yong xu Children's Nutrition Research Center Department of Pediatrics Baylor College of Medicine Department of Molecular and Cellular Biology Section of Endocrinology Diabetes and Metabolism Department of Medicine Baylor College of Medicine Brain Glycemic and Metabolism Control Department Pennington Biomedical Research Center Louisiana State University

Glucose is the primary fuel source of the brain,and therefore glucose levels need to be tightly regulated and maintained within a small physiological range.Certainly,the body necessitates a stable supply of energy mainly provided by glucose for various bodily functions.High or low blood glucose levels would impair the physiological functions of various organs of the body.Prolonged high blood glucose(i.e.,

关键词： HYPOGLYCEMIA

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Barrier Option Pricing in Regime Switching Models with Rebates

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 849-861页

作者： Yue-xu ZHAO Jia-yong BAO School of Economics Hangzhou Dianzi UniversityHangzhou 310018China School of Sciences Hangzhou Dianzi UniversityHangzhou 310018China

This paper is concerned with the valuation of single and double barrier knock-out call options in a Markovian regime switching model with specific rebates.The integral formulas of the rebates are derived via matrix Wiener-Hopf factorizations and Fourier transform techniques,also,the integral representations of the option prices are constructed.Moreover,the first-passage time density functions in two-state regime model are derived.As applications,several numerical algorithms and numerical examples are presented.

关键词： option pricing Markovian regime switching Wiener-Hopf factorization Fourier transform

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Effect of short neuropeptide F signaling on larval feeding in Mythimna separata

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Insect Science 2024年第2期31卷 417-434页

作者： mei-mei Li Qi Yang Li-Hui Chen Yan-Ying Li Jun-Xiang Wu Xiang-Li xu State Key Laboratory of Crop Stress Biology in Arid Areas College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi ProvinceChinaand School of Agricultural Sciences Jiangxi Agricultural UniversityNanchangChina

Mythimna separata is a notorious phytophagous pest which poses serious threats to cereal crops owing to the gluttony of the larvae.Because short neuropeptide F(sNPF)and its receptor sNPFR are involved in a diversity of physiological functions,especially in functions related to feeding in insects,it is a molecular target for pest control.Herein,an sNPF and 2 sNPFRs were identified and cloned from M.separata.Bioinformatics analysis revealed that the sNPF and its receptors had a highly conserved RLRFamide C-terminus and 7 transmembrane domains,respectively.The sNPF and its receptor genes were distributed across larval periods and tissues,but 2 receptors had distinct expression patterns.The starvation-induced assay elucidated that sNPF and sNPFR expression levels were downregulated under food deprivation and recovered with subsequent re-feeding.RNA interference knockdown of sNPF,sNPFR1,and sNPFR2 by injection of double-stranded RNA into larvae not only suppressed food consumption and increased body size and weight,but also led to decrease of glycogen and total lipid contents,and increase of trehalose compared with double-stranded green fluorescent protein injection.Furthermore,molecular docking was performed on the interaction mode between sNPFR protein and its ligand sNPF based on the 3-dimensional models constructed by AlphaFold;the results indicated that both receptors were presumably activated by the mature peptide sNPF-2.These results revealed that sNPF signaling played a considerably vital role in the feeding regulation of M.separata and represents a potential control target for this pest.

关键词： feeding regulation Mythimna separata pest control target RNA interference short neuropeptide F sNPF receptors

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Tunable quantum anomalous Hall effects in ferromagnetic van der Waals heterostructures

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National Science Review 2024年第3期11卷 100-107页

作者： Feng xue Yusheng Hou Zhe Wang Zhiming xu Ke He Ruqian Wu yong xu Wenhui Duan Beijing Academy of Quantum Information Sciences State Key Laboratory of Low Dimensional Quantum Physics Department of Physics Tsinghua University Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices Center for Neutron Science and Technology School of Physics Sun Yat-sen University State Key Laboratory of Surface Physics Key Laboratory of Computational Physical Sciences and Department of PhysicsFudan University Frontier Science Center for Quantum Information Department of Physics and Astronomy University of California-Irvine Tencent Quantum Laboratory Tencent Technology(Shenzhen)Co.Ltd RIKEN Center for Emergent Matter Science(CEMS) Institute for Advanced Study Tsinghua University

The quantum anomalous Hall effect（QAHE） has unique advantages in topotronic applications, but it is still challenging to realize the QAHE with tunable magnetic and topological properties for building functional devices. Through systematic first-principles calculations, we predict that the in-plane magnetization induced QAHE with Chern numbers C = ±1 and the out-of-plane magnetization induced QAHE with high Chern numbers C = ±3 can be realized in a single material candidate, which is composed of van der Waals（vdW）coupled Bi and MnBi2Te4monolayers. The switching between different phases of QAHE can be controlled in multiple ways, such as applying strain or（weak） magnetic field or twisting the vdW materials. The prediction of an experimentally available material system hosting robust, highly tunable QAHE will stimulate great research interest in the field. Our work opens a new avenue for the realization of tunable QAHE and provides a practical material platform for the development of topological electronics.

关键词： quantum anomalous Hall effect topological quantum phase transition van der Waals heterostructures tunable Chern number high Chern number

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Capturability-based Fuzzy Footstep Planner for a Biped Robot with Centroidal Compliance

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Journal of Bionic Engineering 2024年第1期21卷 84-100页

作者： Zihan xu Qin Fang yong Ren Chengju Liu Robot and Artificial Intelligence Lab(RAIL) College of Electronic and Information EngineeringTongji UniversityShanghai 201804China Applied Technology College Soochow UniversitySuzhou 215000China

Compliance motion and footstep adjustment are active balance control strategies from learning human subconscious behaviors.The force estimation without direct end-actuator force measurement and the optimal footsteps based on complex analytical calculation are still challenging tasks for elementary and kid-size position-controlled robots.In this paper,an online compliant controller with Gravity Projection Observer(GPO),which can express the external force condition of perturbations by the estimated Projection of Gravity(PoG)with estimation covariance,is proposed for the realization of disturbance absorption,with which the robustness of the humanoid contact with environments can be maintained.The fuzzy footstep planner based on capturability analysis is proposed,and the Model Predictive Control(MPC)is applied to generate the desired steps.The fuzzification rules are well-designed and give the corresponding control output responding to complex and changeable external disturbances.To validate the presented methods,a series of experiments on a real humanoid robot are conducted.The results verify the effectiveness of the proposed balance control framework.

关键词： Biped walking Centroidal compliance Gravity projection observer Fuzzy footstep planner

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Enhanced photocatalytic hydrogen production from Co-MOF/CN by nitrogen and sulfur co-doped coal-based carbon quantum dots

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Journal of Rare Earths 2024年第5期42卷 838-850,I0002页

作者： Shiyong xu mei Li Yijun Wang Caiyun Gao Rongsheng xu Zhiliang jin School of Chemistry and Chemical Engineering North Minzu UniversityYinchuan750021China Ningxia Key Laboratory of Solar Chemical Conversion Technology.North Minzu University.Yinchuan 750021China State Key Laboratory of National Ethnic Affairs Commission Chemical Technology.North Minzu University Yinchuan750021China

A novel composite photocatalyst for photocatalytic decomposition of water for hydrogen evolution was successfully synthesized by in-situ growth of nitrogen and sulfur co-doped coal-based carbon quantum dots(NSCQDs)nanoparticles on the surface of sheet cobalt-based metal-organic framework(Co-MOF)and graphitic carbon nitride(g-C_(3)N_(4),CN).The structure and properties of the obtained catalysts were systematically analyzed.NSCQDs effectively broaden the absorption of Co-MOF and CN in the visible region.The new composite photocatalyst has high hydrogen production activity and the hydrogen production rate reaches 6254μmol/(g·h)at pH=9.At the same time,NSCQDs synergy Co-MOF/CN composites have good stability.After four cycles of hydrogen production,the performance remains relatively stable.The tran sient photocurrent response and Nyquist plot experimental results further demonstrate the improvement of carrier separation efficiency in composite catalysts.The semiconductor type(n-type semico nductor)of the single-phase catalyst was determined by the Mott-Schottky test,and the band structure was analyzed.The conductive and valence bands of CN are-0.99 and 1.72 eV,respectively,and the conduction and valence bands of Co-MOF are-1.85 and 1.33 eV,respectively.Th e mechanism of the photocatalytic reaction can be inferred,that is,Z-type heterojunction is formed between CN an d Co-MOF,and NSCQDs was used as cocatalyst.

关键词： Nitrogen and sulfur co-doped Coal-based carbon quantum dots Co-MOF CN Photocatalytic hydrogen evolution Rare earths

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Black tea markets worldwide: Are they integrated?

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Journal of Integrative Agriculture 2022年第2期21卷 552-565页

作者： xu yong-mei QIAO Fang-bin HUANG Ji-kun School of Economics Zhejiang Gongshang UnviersityHangzhou 310018P.R.China China Economics and Management Academy Central University of Finance and EconomicsBeijing 100081P.R.China China Center for Agricultural Policy Peking UniversityBeijing 100871P.R.China

Global tea consumption has risen significantly alongside rapid expansion of international trade in recent years.However,few studies have systematically examined the relationship among the major tea markets worldwide.Using weekly data from 2012-2019,this study empirically analyzed the price series of the world’s major black tea auction markets.The estimation results showed that these markets are connected,even though heterogeneities vary.This finding holds not only for regional markets but also for international markets.The findings offer important implications for tea-producing countries with millions of smallholder farmers.

关键词： black tea market price integration VECM

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Effects of operating conditions on iron(hydr)oxides evolution and ciprofloxacin degradation in potassium ferrate-ozone stepwise oxidation system

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Journal of Environmental Sciences 2024年第1期135卷 367-378页

作者： Xiaochen Li Yifan Wang Ning Wang mei Li Maomao Bai Jingtao xu Hongbo Wang School of Municipal and Environmental Engineering Shandong Jianzhu UniversityJinan 250101China Resources and Environment Innovation Institute Shandong Jianzhu UniversityJinan 250101China

In this study,a stepwise oxidation system of potassium ferrate(K_(2)FeO_(4))combined with ozone(O+3)was used to degrade ciprofloxacin(CIP).The effects of pH and pre-oxidation time of K_(2)FeO_(4) on the evolution of K_(2)FeO_(4) reduction products(iron(hydr)oxides)and CIP degradation were investigated.It was found that in addition to its own oxidation capacity,K_(2)FeO_(4) can also influence the treatment effect of CIP by changing the catalyst content.The presence of iron(hydr)oxides effectively enhanced the mineralization rate of CIP by catalyzing ozonation.The pH value can influence the content and types of the components with catalytic ozonation effect in iron(hydr)oxides.The K_(2)FeO_(4) pre-oxidation stage can produce more iron(hydr)oxides with catalytic components for subsequent ozonation,but the evolution of iron(hydr)oxides components was influenced by O_(3) treatment.It can also avoid the waste of oxidation capacity owing to the oxidation of iron(hydr)oxides by O_(3) and free radicals.The intermediate degradation products were identified by Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS).Besides,the degradation pathways were proposed.Among the degradation products of CIP,the product with broken quinolone ring structure only appeared in the stepwise oxidation system.

关键词： Potassium ferrate reduction products Catalytic ozonation Ciprofloxacin Potassium ferrate pre-oxidation time

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