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Optical Transient Source AT2021lfa:A Possible“Dirty Fireball”

Research in Astronomy and Astrophysics 2024年第4期24卷 124-133页

作者： Xue-Mei Ye Da-Ming Wei Yi-Ming zhu zhi-Ping Jin 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 National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China

AT2021lfa,also known as ZTF21aayokph,was detected by the Zwicky Transient Facility on 2021 May 4,a 05:34:48 ***-up observations were conducted using a range of ground-based optical telescopes,as wel as Swift/XRT and VLA ***2021lfa is classified as an“orphan afterglow”candidate due to its rapid flux decline and its reddened color(g-r=0.17±0.14 mag).For an optical transient source without promp gamma-ray detection,one key point is to determine its burst *** we measure the burst time through fitting the initial bump feature of AT2021lfa and obtain its burst time as 2021 May 3,at 22:09:50 *** afterglowpy,we model the multi-band afterglow of AT2021lfa and find that the standard model canno reproduce the late radio observations *** that the microphysical parameters ε_(e),ε_(B)(the energy fraction given to electrons and magnetic field),andξN(the fraction of accelerated electrons)may vary with time we then model the afterglow of AT2021lfa taking into account the temporal evolution of the physical parameters ε_(e),ε^(B),and ξ_(N) and find in this case the multi-wavelength observations can be reproduced *** initial Lorentz factor of AT2021lfa can be estimated from the peak time of the early afterglow,which yields a value of about 18 suggesting that AT2021lfa should be classified as a“dirty fireball.”From the upper limit for the prompt emission energy of AT2021lfa,we obtain that the radiation efficiency is less than 0.02%,which is much smaller than that of ordinary gamma-ray bursts(GRBs).It is also interesting that the fitted values of jet angle and viewing angle are very large,θ_(c)~0.66 rad,θ_(v)~0.53 rad,which may lead to the low Lorentz factor and radiation *** compared with GRB afterglow samples,it is evident that the onset bump timescale of AT2021lfa satisfies the empirical relationships observed in GRB ***,the luminosity of AT2021lfa falls within the range of observations for GRB samples;howeve

关键词： gamma-rays:ISM methods:numerical radiation mechanisms:non-thermal

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A Low Cost, Green Sustainable and Biodegradable Biomass-based Fluorine-free Water and Oil Repellent

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Chinese Journal of Polymer Science 2024年第4期42卷 480-491页

作者： zhi-Wei Shen Shu-Feng Hu Chen Zeng Wei-Qing Kong Mei-Fang zhu State Key Laboratory for Modification of Chemical Fibers&Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China State Key Laboratory of Pulp and Paper Engineering School of Light Industry and EngineeringSouth China University of TechnologyGuangzhou510630China

With the global ban on plastics intensifying, the substitution of plastic with paper has garnered increasing attention. However, the inadequate water and oil repellency of pulp molding hinders its practical applications. Currently, the common method to enhance the oil and water repellency of pulp molding is by adding fluorinated water and oil repellents. Nevertheless, fluorinated compounds are environmentally and physiologically harmful. Therefore, the development of fluorine-free, water and oil repellent alternatives is crucial. In this study, chitosan and stearic acid were utilized as the first and second layers of the oil and water repellent coatings, respectively. The coated samples exhibited favorable water repellency, with a water contact angle of 116.4°, and excellent oil repellency, achieving a 12/12 rating on the kit scale. Importantly, the samples did not exhibit any leakage after being soaked in hot water and hot oil at 95±5℃ for 30 min, demonstrating remarkable performance as a barrier against hot water and oil. Moreover, the coated samples displayed outstanding mechanical properties, thermal stability, biodegradability, and recyclability. The approach presented in this study is simple, cost-effective, environmentally friendly, and represents a promising technique for producing fluoride-free, oil-and water-resistant pulp molding products.

关键词： Biomass Fluoride-free Oil-andwater-resistant Plasticfree

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Elevated nitrogen and co-evolution history with competitors shape the invasion process of Galinsoga quadriradiata

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Journal of Plant Ecology 2024年第4期17卷 9-22页

作者： Wen-Gang Zhang Xing-jiang Song Laís Petri Gang Liu Xiao-Yan Chen Rui-Ling Liu Fang-Fang Huang jia-Bin Zou zhi-Hong zhu College of Life Sciences Shaanxi Normal UniversityXi’an 710119China School for Environment and Sustainability University of MichiganAnn ArborMI 48109USA Research Center for UAV Remote Sensing Shaanxi Normal UniversityXi’an 710119China Changqing Teaching&Research Base of Ecology Shaanxi Normal UniversityXi’an 710119China Guangdong Provincial Key Laboratory of Silviculture Protection and UtilizationGuangdong Academy of ForestryGuangzhou 510520China

Invasive plants usually experience population differentiation as they expand from their initial invasive range to the ***,invasive plants usually encounter competitors which shared different co-evolutionary histories with *** factors may lead to varying responses of invasive plant populations to elevated nitrogen deposition during ***,this issue has received limited attention in prior *** address these challenges,we conducted a greenhouse experiment to investigate how population differentiation of Galinsoga quadriradiata interacts with the presence of various competitors in response to increased nitrogen *** types(new or old that shared short or long co-evolutionary history with the invader,respectively)were set to compete with the invasive central and edge populations under different nitrogen addition *** from the central population of ***,originating from the initial invasion range,showed greater total mass,reproduction and interspecific competitiveness compared with the edge *** addition improved growth and reproductive performance in both populations,and the central population had a stronger response compared with the edge *** performance of *** was inhibited more effectively by old competitors than new *** results indicate that population differentiation occurs in terms of growth and competitiveness during the range expansion of ***,with the central population exhibiting superior ***-evolutionary history with competitors is considered unfavorable for invasive plants in this *** results highlight the combined effects of population differentiation in invasive species and their co-evolution history with competitors in the context of global change factors.

关键词： Galinsoga quadriradiata central population edge population interspecific competition population differentiation elevated nitrogen

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A function-based behavioral modeling method for air combat simulation

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Journal of Systems Engineering and Electronics 2024年第4期35卷 945-954页

作者： WANG Tao zhu zhi ZHOU Xin JING Tian CHEN Wei College of Systems Engineering National University of Defense TechnologyChangsha 410073China Institute of Communication and Navigation Air Force Research AcademyBeijing 100085China

Today’s air combat has reached a high level of uncertainty where continuous or discrete variables with crisp values cannot be properly represented using fuzzy sets. With a set of membership functions, fuzzy logic is well-suited to tackle such complex states and actions. However, it is not necessary to fuzzify the variables that have definite discrete ***, the aim of this study is to improve the level of model abstraction by proposing multiple levels of cascaded hierarchical structures from the perspective of function, namely, the functional decision tree. This method is developed to represent behavioral modeling of air combat systems, and its metamodel,execution mechanism, and code generation can provide a sound basis for function-based behavioral modeling. As a proof of concept, an air combat simulation is developed to validate this method and the results show that the fighter Alpha built using the proposed framework provides better performance than that using default scripts.

关键词： air combat behavioral modeling intelligent agent

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Molecular mechanism for the unusual enhancement of the second-step chemiluminescence production from the carcinogenic tetrabromohydroquinone and H2O_(2)

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Journal of Environmental Sciences 2024年第7期141卷 330-342页

作者： Zi-Han Wang Chun-Hua Huang zhi-Sheng Liu Li Mao Ben-Zhan zhu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Environment and Resources University of Chinese Academy of SciencesBeijing 100049China

We have found recently that two-step intrinsic hydroxyl radical(·OH)-dependent chemiluminescence(CL)could be produced by carcinogenic tetrahaloquinone and H_(2)O_(2).However,the first-step CL was too fast to clearly detect the stepwise generation of·OH and CL,and to distinguish the exact dividing point between the first-step and second-step *** we found that,extremely clear two-step intrinsic CL could be produced by the relative slow reaction of tetrabromohydroquinone(TBHQ)with H_(2)O_(2),which was directly dependent on the two-step·OH ***,the second-step,but not the first-step CL production of TBHQ/H_(2)O_(2)(CRET donor)was markedly enhanced by fluorescein(a typical xanthene dye,CRET acceptor)through a unique chemiluminescence resonance energy transfer(CRET)*** novel CRET system of TBHQ/H_(2)O_(2)/fluorescein was successfully applied for the sensitive detection of TBHQ with the detection limit as low as 2.5μmol/*** findings will help to develop more sensitive and highly efficient CL or CRET systems and specific CL sensor to detect the carcinogenic haloquinones,which may have broad environmental applications.

关键词： Two-step chemiluminescence Bromohydroquinone Hydrogen peroxide Hydroxyl radical CRET

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Dynamic coupling of ferrihydrite transformation and associated arsenic desorption/redistribution mediated by sulfate-reducing bacteria

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Journal of Environmental Sciences 2024年第1期135卷 39-50页

作者： Wenjing Zhou Huiyan zhu Shiwen Hu Bowei Zhang Kun Gao zhi Dang Chongxuan Liu State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSouth China University of TechnologyGuangzhou 510006China

Sulfate-reducing bacteria play an important role in the geochemistry of iron(oxyhydr)oxide and arsenic(As)in natural environments;however,the associated reaction processes are yet to be fully *** this study,batch experiments coupled with geochemical,spectroscopic,microscopic,and thermodynamic analyses were conducted to investigate the dynamic coupling of ferrihydrite transformation and the associated As desorption/redistribution mediated by Desulfovibrio vulgaris(***).The results indicated that *** could induce ferrihydrite transformation via S^(2-)-driven and direct reduction *** the absence of SO_(4)^(2-),*** directly reduced ferrihydrite,and As desorption and re-sorption occurred simultaneously during the partial transformation of ferrihydrite to *** increase in SO_(4)^(2-)loading promoted the S^(2-)-driven reduction of ferrihydrite and accelerated the subsequent mineralogical *** the low and medium SO_(4)^(2-)treatments,ferrihydrite was completely transformed to a mixture of magnetite and mackinawite,which increased the fraction of As in the residual phase and stabilized *** the high SO_(4)^(2-)treatment,although the replacement of ferrihydrite by only mackinawite also increased the fraction of As in the residual phase,22.1%of the total As was released into the solution due to the poor adsorption affinity of As to mackinawite and the conversion of As^(5+)to As^(3+).The mechanisms of ferrihydrite reduction,mineralogy transformation,and As mobilization and redistribution mediated by sulfate-reducing bacteria are closely related to the surrounding SO_(4)^(2-)*** results advance our understanding of the biogeochemical behavior of Fe,S,and As,and are helpful for the risk assessment and remediation of As contamination.

关键词： Sulfate-reducing bacteria Arsenic Ferrihydrite Transformation Redistribution

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反相高效液相色谱法测定对羟基苯海因的研究

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理化检验（化学分册） 2005年第3期41卷 190-191页

作者：朱智甲东华大学化学化工学院上海200051

建立了测定对羟基苯海因(HPHT)的反相高效液相色谱法。固定相为 Spherigel ODSC18柱,流动相为乙睛水四氢呋喃冰乙酸,体积比为 70∶30∶05∶0.5,检测波长为 254nm。方法的线性范围为0.1~17.5 mg,回归方程 A=2 062.3 m-293.3,相关系数... 详细信息

建立了测定对羟基苯海因(HPHT)的反相高效液相色谱法。固定相为 Spherigel ODSC18柱,流动相为乙睛水四氢呋喃冰乙酸,体积比为 70∶30∶05∶0.5,检测波长为 254nm。方法的线性范围为0.1~17.5 mg,回归方程 A=2 062.3 m-293.3,相关系数为 0.999 5,相对标准偏差为0.86%,检出限为4.3μg,加标回收率为99.3%~102.0%。

关键词：反相高效液相色谱法对羟基苯海因 C18柱

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Identification of Early Warning Signals of Infectious Diseases in Hospitals by Integrating Clinical Treatment and Disease Prevention

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Current Medical Science 2024年第2期44卷 273-280页

作者： Lei ZHANG Min-ye LI Chen zhi Min zhu Hui MA Sixth Medical Center Chinese PLA General HospitalBeijing100048China The Nursing Department Chinese PLA General HospitalBeijing 100853China

The global incidence of infectious diseases has increased in recent years,posing a significant threat to human *** typically serve as frontline institutions for detecting infectious ***,accurately identifying warning signals of infectious diseases in a timely manner,especially emerging infectious diseases,can be ***,there is a pressing need to integrate treatment and disease prevention data to conduct comprehensive analyses aimed at preventing and controlling infectious diseases within *** paper examines the role of medical data in the early identification of infectious diseases,explores early warning technologies for infectious disease recognition,and assesses monitoring and early warning mechanisms for infectious *** propose that hospitals adopt novel multidimensional early warning technologies to mine and analyze medical data from various systems,in compliance with national strategies to integrate clinical treatment and disease ***,hospitals should establish institution-specific,clinical-based early warning models for infectious diseases to actively monitor early signals and enhance preparedness for infectious disease prevention and control.

关键词： infectious disease disease prevention and control medical data warning signals

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氧化钨薄膜对发光二极管特性的影响研究

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光电子．激光 2021年第4期32卷 344-348页

作者：肖和平朱志佳华灿光电(苏州)有限公司江苏苏州215600

氧化钨薄膜具有适中的光学带隙、折射率及高功函数等半导体特性,本文采用溅射法(Sputtering)制备氧化钨薄膜测试其光电特性,使用AFM、XRD观察薄膜外观结构与晶体状态,应用XPS、UPS表征薄膜的化学计量组分及薄膜功函数,并将此薄膜应用于A... 详细信息

氧化钨薄膜具有适中的光学带隙、折射率及高功函数等半导体特性,本文采用溅射法(Sputtering)制备氧化钨薄膜测试其光电特性,使用AFM、XRD观察薄膜外观结构与晶体状态,应用XPS、UPS表征薄膜的化学计量组分及薄膜功函数,并将此薄膜应用于AlGaInP发光二极管器件中,以增加与p-GaP欧姆接触特性,增加载流子注入效率;测试结果表明:采用合适厚度的氧化钨虚设层与ITO形成的复合膜层可有效增加电子注入效率,使AlGaInP发光二极管的出光强度提高4%,同时正向电压降低0.01V。

关键词：氧化钨函数等 AlGaInP发光二极管出光效率

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Robust asymmetric Cherenkov radiation in tilted anisotropic medium

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 46-51页

作者： Shuwen Xue Yadong Xu Linkang Han zhi Ning Chen Qiaoliang Bao Shan zhu Huanyang Chen Institute of Electromagnetics and Acoustics and Department of Physics College of Physical Science and TechnologyJiujiang Research InstituteXiamen UniversityXiamen 361005China School of Physical Science and Technology Institute of Theoretical and Applied PhysicsSoochow UniversitySuzhou 215006China Department of Electrical and Computer Engineering National University of SingaporeSingapore 8117583Singapore Institute of Energy Materials Science(IEMS) University of Shanghai for Science and TechnologyShanghai 200093China

Cherenkov radiation(CR)is available for a wide variety of terahertz(THz)radiation sources,but its efficiency is deeply affected by intrinsic *** find that if the tilted angle(α)of anisotropic material and radiation angle(θ)meet the condition ofθ+α=π/2,the intensity of radiation fields for the charged particle bunch(CPB)moving from left to right cannot be influenced by intrinsic losses,which means long-distance radiation can be ***,we observe an asymmetric CR when the CPB moves from the opposite *** addition,we select natural van der Waals(vd W)materialα-MoO3as an example,further confirming that the radiation field can reach the far field and the asymmetric CR radiation can also be *** wonderful properties with long-distance radiation will extend the application of CR to a certain extent for future design and fabrication.

关键词： asymmetric Cherenkov radiation intrinsic losses long-distance radiation

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