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Pion-induced K^* production with Σ^* baryon off proton target

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Communications in Theoretical Physics 2020年第11期72卷 74-79页

作者： Jie xiang Xiao-yun Wang Hao Xu Jun He Lanzhou University of Technology Lanzhou 730050China Department of Physics Lanzhou University of TechnologyLanzhou 730050China Department of Applied Physics School of ScienceNorthwestern Polytechnical UniversityXi’an 710129China Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjingJiangsu 210097China

In this work,the reactionπ-p→K^*Σ^*is investigated with an effective Lagrangian *** contributions from the Born terms,including the s,t,and u channel,are considered,and the Regge model and the Feynman model are applied to treat the t-channel *** existing experimental data can be reproduced with the best-fittedχ^2 being 2.38 and 1.54 for the Feynman and Regge models,***,it is found that the contribution from the t channel is dominant in the *** contribution of the u channel is mainly distributed at backward angles,and the contribution from the s channel is small and *** the Feynman model,the contribution of the t-channel K exchange is much larger than the contribution of the K^*exchange,while in the Regge model the contribution of the t-channel K exchange is comparable to that of the K^**** about the differential crosssection of theπ-p→K^*Σ^*reaction is also presented,which is helpful for clarifying the role of the Regge *** current results suggest high-precision experimental measurements which can be performed at J-PARC and COMPASS.

关键词： effective Lagrangian approach Regge model hadron states

Parameterizing Stellar Spectra Using Deep Neural Networks

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Research in Astronomy and Astrophysics 2017年第4期17卷 49-56页

作者： xiang-Ru Li Ru-Yang pan Fu-Qing Duan School of Mathematical Sciences South China Normal University College of Information Science and Technology Beijing Normal University

Large-scale sky surveys are observing massive amounts of stellar spectra. The large number of stellar spectra makes it necessary to automatically parameterize spectral data, which in turn helps in statistically exploring properties related to the atmospheric parameters. This work focuses on designing an automatic scheme to estimate effective temperature （Tee）, surface gravity （log g） and metallicity [Fe/H] from stellar spectra. A scheme based on three deep neural networks （DNNs） is proposed. This scheme consists of the following three procedures： first, the configuration of a DNN is initialized using a series of autoencoder neural networks; second, the DNN is fine-tuned using a gradient descent scheme; third, three atmospheric parameters Tefr, log 9 and [Fe/H] are estimated using the computed DNNs. The constructed DNN is a neural network with six layers （one input layer, one output layer and four hidden layers）, for which the number of nodes in the six layers are 3821, 1000, 500, 100, 30 and 1, respectively. This proposed scheme was tested on both real spectra and theoretical spectra from Kurucz＇s new opacity distribution function models. Test errors are measured with mean absolute errors （MAEs）. The errors on real spectra from the Sloan Digital Sky Survey （SDSS） are 0.1477, 0.0048 and 0.1129 dex for log 9, log Tefr and [Fe/H] （64.85 K for Teff）, respectively. Regarding theoretical spectra from Kurucz＇s new opacity distribution function models, the MAE of the test errors are 0.0182, 0.0011 and 0.0112 dex for log 9, log Teff and [Fe/H] （14.90 K for Tdf）, respectively.

关键词： methods: statistical - methods data analysis - stars fundamental parameters - stars atmospheres - stars abundances - techniques spectroscopic

First-principles Study of Electron Transport Through Oligoacenes

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Chinese Journal of Chemical Physics 2009年第1期22卷 7-12页

作者： Zhen pan Qun-xiang Li Qin-wei Shi Xiao-ping Wang Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of China Hefei 230026 China

The electronic transport properties of oligoacenes sandwiched between two Au（111） surfaces with serial and parrallel configurations were investigeted by using a fully self-consistent nonequilibrium Green＇s function method combined with density functional calculations. This theoretical results show that the conductivity of oligoacenes with both sandwiched configurations at low bias voltage is mainly determined by the tail of the transmission peak from the perturbed highest occupied molecular orbital. When the molecular length increases, the zero-bias voltage conductance G（0） of oligoacenes with serial configuration neither follows Magoga＇s exponential law nor displays the even-odd oscillation effect, while the G（O） of the oligoacenes sandwiched with parallel configuration monotonically increases. The reduction of energy gaps, the alignment of the Fermi level, and the spatial distribution of the perturbed molecular orbitals are used to self-consistently explore the transport mechanism through oligoacenes.

关键词： Transport property Oligoacene Zero-bias voltage conductance First-principles calculation

Neutron diffraction studies of permanent magnetic materials

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Rare Metals 2020年第1期39卷 13-21页

作者： Wen-yun Yang Dong Liang xiang-Dong Kong Jin-Bo Yang State Key Laboratory for Mesoscopic Physics School of PhysicsPeking UniversityBeijing100871China Collaborative Innovation Center of Quantum Matter Beijing100871China Beijing Key Laboratory for Magnetoeletric Materials and Devices Beijing100871China Department of Micro-nano Fabrication Technology Institute of Electrical EngineeringChinese Academy of SciencesBeijing100871China

Neutron diffraction technology as an advanced material research technique has special advantages in studying magnetic materials compared to the conventional techniques such as X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).In this review,the applications of neutron diffraction technology on permanent magnetic materials were briefly reviewed:(1)the determination of the crystal structure and magnetic structure of the typical permanent magnet material,(2)in situ neutron diffraction study of the crystal structure evolution of the permanent magnets,and(3)phase transition in permanent magnetic materials.

关键词： Neutron diffraction Permanent magnetic materials Crystal structure Magnetic structure Structure evolution Phase transition

Responses of Plant Community and Soil Properties to Inter-Annual Precipitation Variability and Grazing Durations in a Desert Steppe in Inner Mongolia

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Journal of Integrative Agriculture 2014年第6期13卷 1171-1182页

作者： WANG Zhen yun xiang-jun WEI Zhi-jun Michael P Schellenberg WANG yun-feng YANG Xia HOU xiang-yang Grassland Research Institute Chinese Academy of Agricultural Sciences Department of Grassland Science College of Ecology and Environmental ScienceInner Mongolia Agricultural University Semiarid Prairie Agricultural Research Center (SPARC) Agriculture and Agri-Food Canada

Grazing can dramatically affect arid grassland communities that are very vulnerable to environmental changes due to its relatively short and sparse ground coverage, low biomass, sandy soil and inter-annual precipitation found in the desert steppe. The study investigates the effects of different grazing durations on vegetation and soil properties of a desert steppe community. The experiment was conducted in Xisu Banner in Inner Mongolia with ifve treatments：CG （continuous grazing）, 40UG （40 d ungrazed）, 50UG （50 d ungrazed）, 60UG （60 d ungrazed） and UG （ungrazed）. The biomass of both shrub and annual-biennial plant communities were signiifcantly decreased by CG. Continuous grazing and 40UG signiifcantly reduced the ANPP （aboveground net primary productivity） by the end of the three year study. 60UG treatment increased soil organic carbon （OC）, total nitrogen concentration （TN） and total phosphorus concentration （TP） concentrations and 50UG increased the TN and total phosphorus concentration （TK） concentrations, whereas CG, 40UG and 50UG decreased soil OC, TP and available phosphorus concentration （AP） concentrations. The perennial plant species of the desert steppe were generally tolerant for grazing. The annual-biennial plant species had large variability in ANPP because of the inter-annual precipitation. Our results highlight that inter-annual precipitation variations could strongly modify the community responses to grazing in arid ecosystems.

关键词： ANPP plant species plant fimctional group soil nutrient

Efficacy of arbidol in COVID-19 patients:A retrospective study

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World Journal of Clinical Cases 2021年第25期9卷 7350-7357页

作者： Shuo Wei Sha Xu yun-Hu pan Department of Infectious Diseases Fujian Provincial HospitalFujian Medical UniversityFuzhou 350000Fujian ProvinceChina Department of Infectious Diseases Jinyintan HospitalWuhan 430000Hubei ProvinceChina Department of Respiratory Medicine 907 Hospital of the Joint Logistics TeamNanping 353000Fujian ProvinceChina

To date,no treatment has proven to be absolutely effective for coronavirus disease 2019(COVID-19)patients,and further research is *** a traditional antiviral drug,arbidol was widely used in Wuhan at the beginning of the COVID-19 epidemic and is of increasing interest for treating COVID-19 based on in vitro data suggesting activity against severe acute respiratory syndrome(SARS).Although arbidol has been widely used in China to treat COVID-19 patients,clinical trials to date have not clearly substantiated this *** To evaluate the efficacy of arbidol for *** A retrospective study was conducted on 132 moderate and severe COVID-19 patients admitted to Jinyintan Hospital and Huoshenshan Hospital(officially designated for COVID-19 treatment)from February to March 2020 in Wuhan,*** study mainly evaluated the efficacy of arbidol in patients with COVID-19 in the early stage of the SARS coronavirus 2 *** was administered at a dose of 200 mg,three times a day,with a 10-d course to adults not receiving any other *** to the shortage of beds at the time,not every patient could be admitted *** looked for the early stages of the sudden outbreak,places of limited medical resources,limited ward beds,and delayed admission;thus,some patients naturally fit into the control group who did not receive any antiviral *** of the 132 patients,72 received arbidol treatment,and 60 did *** compared the disease course of the two groups and explored the predictors of extended disease *** Seventy-two patients commenced arbidol,and 60 patients did not receive arbidol *** disease duration in the former group was shorter(23.42±6.92 vs 29.60±6.49,P483.0 ng/mL and lactate dehydrogenase(LDH)>237.5 U/L were found to be independent risk factors for

关键词： COVID-19 SARS-CoV-2 Arbidol Treatment Antiviral

Trace element compositions of pyrite and stibnite:implications for the genesis of antimony mineralization in the Yangla Cu skarn deposit,Northwestern yunnan,China

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Acta Geochimica 2024年第3期43卷 535-554页

作者： Ping pan Xinfu Wang Bo Li Guo Tang Zuopeng xiang Faculty of Land and Resource Engineering Kunming University of Science and TechnologyKunming 650093China Kunming Metallurgy College Kunming 650033China School of Earth Science Yunnan UniversityKunming 650500China Kunming Prospecting Design Institute of China Nonferrous Metals Industry Co. LtdKunming 650051China

The Yangla Cu skarn deposit is located in the central part of the Jinshajiang Suture Zone,southwest China,with a total reserve of 150 Mt Cu@1.03%.The newly discovered antimony orebodies at the depth of Yangla are strictly controlled by the stratum,structure,and lithology,which are lenticular and vein-like within the marble fracture zone,which can provide a window into multistage miner-alization and ore genesis at *** can be divided into three types,Cu–Pb–Zn(skarn)pyrite,galena,and sphalerite,Cu(porphyry)chalcopyrite and pyrite,and Sb(hydrothermal)stibnite and *** mineral assem-blages were stibnite+pyrite+calcite+quartz±minor scheelite in antimony *** study presents quantitative measurements of the trace element compositions of pyrite and stibnite from the Yangla antimony *** of pyrite with electron probe microanalysis(EPMA)showed enrichment in Co,Ni,Sb,As,and Mo,and deficit in its S and Fe contents when compared to the stoichiometric con-centrations of S and Fe in *** Sb-related pyrite may belong to sedimentary-reworked genesis and may be modi-fied by hydrothermalfluids,thereby presenting a certain dif-ference(i.e.,crystal morphology,texture,and chemical com-position)compared to the skarn and porphyry Cu-related pyrite in the Yangla Cu skarn *** of stibnite with EPMA and inductively coupled plasma-mass spectrom-etry showed enrichment in As,Pb,Sn,Pb,Cu,and Zn,and presented much higher Sb contents and slightly lower S con-tents when compared to the stoichiometric concentrations of Sb and S in *** analysis of the stibnite trace elements showed correlations for the elemental pairs Cu–Pb,As–Sb,and Sn–Pb,and the coupled substitution equations Sb^(3+)↔Cu^(+)+Pb^(2+),Sb^(3+)↔As^(3+),and Sn^(2+)↔Pb^(2+)may be the major factors governed the incorporating Cu,Pb,As and Sn within the ***,this study preliminary shows that the antimony mineralization may belong to a car-bonate replacement h

关键词： Trace elements Pyrite Stibnite Substitution mechanisms Antimony mineralization Yangla Cu skarn deposit

Effects of starvation and hormones on DNA synthesis in silk gland cells of the silkworm, Bombyx moil

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Insect Science 2016年第4期23卷 569-578页

作者： Yao-Feng Li xiang-yun Chen Chun-Dong Zhang Xiao-Fang Tang La Wang Tai-Hang Liu Min-Hui pan Cheng Lu State Key Laboratory of Silkworm Genome Biology Southwest University Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry Southwest University Chongqing Department of Biochemistry and Molecular Biology Chongqing Medical University Chongqing China

Silk gland cells of silkworm larvae undergo multiple cycles of endomitosis for the synthesis of silk proteins during the spinning phase. In this paper, we analyzed the endomitotic DNA synthesis of silk gland cells during larval development, and found that it was a periodic fluctuation, increasing during the vigorous feeding phase and being gradually inhibited in the next molting phase. That means it might be activated by a self- regulating process after molting. The expression levels of cyclin E, cdtl and pcna were consistent with these developmental changes. Moreover, we further examined whether these changes in endomitotic DNA synthesis resulted from feeding or hormonal stimulation. The results showed that DNA synthesis could be inhibited by starvation and re-activated by re-feeding, and therefore appears to be dependent on nutrition. DNA synthesis was suppressed by in vivo treatment with 20-hydroxyecdysone （20E）. However, there was no effect on DNA synthesis by in vitro 20E treatment or by either in vivo or in vitro juvenile hormone treatment. The levels of Akt and 4E-BP phosphorylation in the silk glands were also reduced by starvation and in vivo treatment with 20E. These results indicate that the activation of endomitotic DNA synthesis during the intermolt stages is related to feeding and DNA synthesis is inhibited indirectly by 20E.

关键词： Bombyx mori DNA synthesis endomitosis silk gland starvation 20-hydroxyecdysone

Improving naive Bayes classifier by dividing its decision regions

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第8期12卷 647-657页

作者： Zhi-yong YAN Gong-fu XU yun-he pan Institute of Artificial Intelligence Zhejiang University Hangzhou 310027 China

Classification can be regarded as dividing the data space into decision regions separated by decision *** this paper we analyze decision tree algorithms and the NBTree algorithm from this ***,a decision tree can be regarded as a classifier tree,in which each classifier on a non-root node is trained in decision regions of the classifier on the parent ***,the NBTree algorithm,which generates a classifier tree with the C4.5 algorithm and the naive Bayes classifier as the root and leaf classifiers respectively,can also be regarded as training naive Bayes classifiers in decision regions of the C4.5 *** propose a second division (SD) algorithm and three soft second division (SD-soft) algorithms to train classifiers in decision regions of the naive Bayes *** four novel algorithms all generate two-level classifier trees with the naive Bayes classifier as root *** SD and three SD-soft algorithms can make good use of both the information contained in instances near decision boundaries,and those that may be ignored by the naive Bayes ***,we conduct experiments on 30 data sets from the UC Irvine (UCI) *** results show that the SD algorithm can obtain better generali-zation abilities than the NBTree and the averaged one-dependence estimators (AODE) algorithms when using the C4.5 algorithm and support vector machine (SVM) as leaf *** experiments indicate that our three SD-soft algorithms can achieve better generalization abilities than the SD algorithm when argument values are selected appropriately.

关键词： Naive Bayes classifier Decision region NBTree C4.5 algorithm Support vector machine (SVM)