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Injection Spectra of Different Species of Cosmic Rays from AMS-02, ACE-CRIS and Voyager-1

Research in Astronomy and Astrophysics 2023年第11期23卷 7-13页

作者： xu pan Qiang Yuan Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China

Precise measurements of energy spectra of different cosmic ray(CR) species have been obtained in recent years, by particularly the AMS-02 experiment on the International Space Station. It has been shown that apparent differences exist in different groups of the primary CRs. However, it is not straightforward to conclude that the source spectra of different particle groups are different since they will experience different propagation processes(e.g., energy losses and fragmentations) either. In this work, we study the injection spectra of different nuclear species using the measurements from Voyager-1 outside the solar system, and ACR-CRIS and AMS-02 on the top of atmosphere, in a physical framework of CR transportation. Two types of injection spectra are assumed, the broken power-law(BPL) form and the non-parametric spline interpolation form. The non-parametric form fits the data better than the BPL form, implying that potential structures beyond the constrained spectral shape of BPL may exist. For different nuclei the injection spectra are overall similar in shape but do show some differences among each other. For the non-parametric spectral form, the helium injection spectrum is the softest at low energies and the hardest at high energies. For both spectral shapes, the low-energy injection spectrum of neon is the hardest among all these species, and the carbon and oxygen spectra have more prominent bumps in 1–10 GV in the R2 d N *** differences suggest the existence of differences in the sources or acceleration processes of various nuclei of CRs.

关键词： (ISM:)cosmic rays acceleration of particles astroparticle physics

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Management of Colorado potato beetle in invasive frontier areas

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Journal of Integrative Agriculture 2020年第2期19卷 360-366页

作者： WANG Cong xu Han pan xu-bin Institute of Plant Quarantine Chinese Academy of Inspection and Quarantine

Colorado potato beetle(CPB)is one of the most devastating invasive insects and it is native to North *** feeds on several wild species of the genus Solamum,such as *** and *** Dunal,and is one of the major pests of potato and *** in the early 19 th century,CPB has rapidly spread across North America,Europe,and Central *** was first reported to invade Xinjiang of China in 1993 and it was effectively controlled in Mori *** 2013,CPB has also been found in Jilin and Heilongjiang in Northeast China,and it likely migrated to these provinces from ***,China has become the frontier for the global CPB spread,and risk management and monitoring systems for this pest are urgently ***,we summarize pest management methods that are used in areas at the frontier of the CPB invasion,and put forward frameworks for further preventing and controlling of the spread of *** management methods for CPB can also serve as an example for the control of invasive species mitigation in frontier areas.

关键词： potential geographical distribution monitoring strategies host management

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Interpretation of the DAMPE 1.4 Te V peak according to the decaying dark matter model

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Science China(Physics,Mechanics & Astronomy) 2018年第10期61卷 36-42页

作者： xu pan Cun Zhang Lei Feng Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences School of Physics Nanjing University

Highly accurate measurements of cosmic ray electron flux by the dark matter particle explorer （DAMPE） ranging between 25 GeV and 4.6 TeV have recently been published. A sharp peak structure was found at - 1.4 TeV. This unexpected peak structure can be reproduced by the annihilation/decay of a nearby dark matter （DM） halo. In this study, we adopt the decaying-DM model to interpret the - 1.4 TeV peak. We found that the decay products of the local DM subhalo could contribute to the DMAPE peak with mDM = 3 TeV and r - 10^28 s. We also obtain constraints on DM lifetime and the distance of the local DM subhalo by comparison with DAMPE data.

关键词： dark matter cosmic ray DAMPE

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Highly efficient and stable perovskite solar cells with strong hydrophobic barrier via introducing poly(vinylidene fluoride)additive

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Journal of Energy Chemistry 2021年第6期30卷 593-600,I0014页

作者： Haiying Zheng Guozhen Liu Weiwei Wu Huifen xu xu pan Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601AnhuiChina Key Laboratory of Photovoltaic and Energy Conservation Materials Institute of Solid State PhysicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031AnhuiChina

Perovskite solar cells(PSCs)have become the promising next-generation photovoltaic devices due to their excellent photoelectric performances,and the power conversion efficiencies(PCEs)have experienced unprecedented rapid increase in recent ***,to realize the practical application of PSCs,high performance and long-term stability are required and the preparation of high-quality perovskite film is the ***,we adopt a simple and effective method to prepare high-quality perovskite films by introducing the poly(vinylidene fluoride)(PVDF)polymer additive with abundant hydrophobic *** the growth template,the PVDF promotes the growth of perovskite crystal,improves the crystallinity and film morphology,thus reducing defect density and inhibiting carrier *** results show that the photovoltaic performances of the perovskite device with PVDF are meaningfully improved,and a high PCE of 21.42%is achieved with an improvement of 10.87%,More importantly,the PVDF-based perovskites display greatly enhanced humidity and heat stability due to the protection of strong hydrophobic barrier from F and PVDF long *** at 45%±5%relative humidity(RH)for 2400 h and 850 C for300 h,respectively,the unsealed PVDF devices can maintain over 90%of the initial *** indicates that suitable polymer additives can improve the film quality to acquire high-performance and stable PSCs and lay a foundation to design new perovskite light absorption layer with different polymers for the further development of PSCs.

关键词： Perovskite solar cells Poly(vinylidene fluoride) Polymer additive Hydrophobic barrier Long-term stability

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The Law of Logarithm for Arrays of Random Variables under Sub-linear Expectations

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Acta Mathematicae Applicatae Sinica 2020年第3期36卷 670-688页

作者： Jia-pan xu Li-xin ZHANG School of Mathematical Sciences Zhejiang UniversityHangzhou310027China

Under the framework of sub-linear expectation initiated by Peng,motivated by the concept of extended negative dependence,we establish a law of logarithm for arrays of row-wise extended negatively dependent random variables under weak ***,the law of logarithm for independent and identically distributed arrays is derived more precisely and the sufficient and necessary conditions for the law of logarithm are obtained.

关键词： sub-linear expectation capacity exponential inequality extended negative dependence the law of logarithm

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Three Series Theorem for Independent Random Variables under Sub-linear Expectations with Applications

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Acta Mathematica Sinica,English Series 2019年第2期35卷 172-184页

作者： Jia pan xu Li Xin ZHANG School of Mathematical Sciences Zhejiang University

In this paper, motived by the notion of independent and identically distributed random variables under the sub-linear expectation initiated by Peng, we establish a three series theorem of independent random variables under the sub-linear expectations. As an application, we obtain the Marcinkiewicz's strong law of large numbers for independent and identically distributed random variables under the sub-linear expectations. The technical details are different from those for classical theorems because the sub-linear expectation and its related capacity are not additive.

关键词： Sub-linear expectation capacity Rosenthal's inequality Kolmogorov's three series theorem Marcinkiewicz's strong law of large numbers

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Regulating the mesogenic properties of imidazolium salts by modifying N3-substituents

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Science China Chemistry 2015年第12期58卷 1884-1890页

作者： Meng Wang xu pan Jian Chen Songyuan Dai Anhui Electric Power Design Institute Key Laboratory of Novel Thin Film Solar Cells Institute of Plasma Physics Chinese Academy of Sciences Beijing Key Laboratory of Novel Thin Film Solar Cells North China Electric Power University

In this study, a series of imidazolium salts with different N3-substituents(3-position: methyl, vinyl, ethyl, n-propyl, n-butyl)-based ionic-liquid crystals with iodide as counterion(ILCs) are synthesized and characterized, with the aim of regulating the mesogenic properties of imidazolium salts. The imidazolium salts-based ionic-liquid crystals are characterized by thermal analysis, polarized optical microscopy, X-ray powder diffraction, and single-crystalline diffraction. Liquid crystalline phase with a Smectic A phase interdigitated bilayer structure is observed. The mesophase temperature range decreases with the increase of the alkyl chain length of N3-substituent. While when vinyl is attached to the N3 position, intermolecular ?-? interactions are formed in adjacent layers, which exert a positive effect on the formation of mesophase. The layer-spacing of imidazolium salts keeps increasing with the increase of the alkyl chain length attached to both the N1 and N3 positions, and gradually decreases with the increasing temperature in liquid crystalline phase. The 1-alkyl-3-vinylimidazolium salt has the smallest layer-spacing, due to the intermolecular ?-? interactions between the vinyl and imidazolium rings in adjacent layers.

关键词： ionic liquid crystals mesogenic properties regulate N3-substituents

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Optimization of large capacity six-strand tundish with flow channel for adapting situation of fewer strands casting

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Journal of Iron and Steel Research International 2021年第9期28卷 1114-1124页

作者： Cheng Yao Min Wang Ming-xu pan Yan-ping Bao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China Daye Special Steel Co. Ltd.Huangshi435000HubeiChina

Closing a single nozzle or multiple nozzles for a temporary casting operation(fewer strands casting)was common in a tundish due to insufficient molten steel or equipment ***,nozzle clogging usually happens under the situation of fewer strands ***,a temperature deviation index was introduced to characterize the temperature stratification of molten steel for a large capacity tundish,and a new calculation method of residence time curve was used to describe the different flow types of molten steel at each *** on hydraulics experiment and numerical simulation,important parameters of present case and modified case were *** the situation of fewer strands casting,the proportion of internal-recycle flow after modification decreased from 30.68%to 24.55%;the standard deviation of the response time reduced from 27.59 to 13.16,and the interquartile range of temperature deviation index changed from 0.89 to 0.27.

关键词： Large capacity tundish Fewer strands casting Internal-recycle flow Strands consistency Temperature deviation index

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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)

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Emission-Tunable Nanofluorophores through Self-assembly of Amphiphilic Block Copolymers:toward Application in Cell Imaging

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Chinese Journal of Chemistry 2023年第8期41卷 931-938页

作者： Shensong Zhang Shuang Qi Xiongfei He pan xu Bo Song College of Chemistry Chemical Engineering and Materials ScienceSoochow UniversitySuzhouJiangsu215123 China Physical Chemistry I&Research Center of Micro-and Nanochemistry and(Bio)Technology(Cμ) Department of Chemistry and BiologySchool of Science and TechnologyUniversity of SiegenAdolf-Reichwein-Str.257076 SiegenGermany

Comprehensive Summary Nanofluorophores based on aggregation-induced emission(AIE)dyes have recently received considerable attention because of their unique optical properties and *** this work,we report an emission-tunable nanofluorophore constructed by the self-assembly of an amphiphilic block copolymer(denoted by PTN).The diblock copolymer was synthesized by RAFT polymerization.A polyethylene glycol-based trithiocarbonate was employed as the macromolecular chain transfer agent,and a near-infrared emitting tetraphenylethylene derivative with a vinyl terminal group was designed as the *** block copolymers self-assembled in an aqueous solution to form nanospheres,which showed near-infrared emission at approximately 720 nm with a significant Stokes shift of approximately 260 ***,nanofluorophores have excellent biocompatibility,photostability,and pH-independent emission-tunable properties,and were successfully applied to label HeLa cells for fluorescence imaging.

关键词： Block copolymers Nanoparticles Fluorescent probes Aggregation-induced emission Twisted intramolecular charge transfer

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