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Biomedical and Environmental Sciences 2021年第9期34卷 729-733页

作者： Tahir Yaqub Muhammad Nawaz Muhammad Z.Shabbir Muhammad A.Ali Imran Altaf sohail Raza Muhammad A.B.Shabbir Muhammad A.Ashraf Syed Z.Aziz sohai l q.cheema Muhammad B.Shah Saira Rafique sohail Hassan Nageen Sardar Adnan Mehmood Muhammad W.Aziz Sehar Fazal Nadir Hussain Muhammad T.Khan Muhammad M.Atique Ali Asif Muhammad Anwar Nabeel A.Awan Muhammad U.Younis Muhammad A.Bhattee Zarfishan Tahir Nadia Mukhtar Huda Sarwar Maaz S.Rana Omair Farooq Institute of Microbiology University of Veterinary and Animal SciencesLahorePakistan Water and Sanitation Agency LahorePunjabPakistan Specialized Healthcare&Medical Education Department PunjabPakistan Primary and Secondary Healthcare Department PunjabPakistan Institute of Public Health LahorePakistan Farooq Hospital LahorePakistan

In 2019,the newly emerged SARS-CoV-2 virus caused pneumonia-like *** disease rapidly spread globally,leading to a worldwide outbreak referred to as the COVID-19 pandemic.

关键词： globally Strategy Smart

Viscosity and structure relationship with equimolar substitution of CaO with MgO in the CaO–MgO–Al_(2)O_(3)–SiO_(2)slag melts

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 70-79页

作者： Yong Hou Shuo Zhang Jie Dang Jia Guo Hanghang Zhou Xuewei lü College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this *** most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina *** results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO *** transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO *** of the Raman spectra showed that the average number of bridging oxygens per Si atom and the X_(q^(3))/X_(q^(2))(X_(q^(i))is the molar fraction of q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents *** analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO ***,bond strength is another important factor affecting the slag *** occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.

关键词： aluminosilicate viscosity structure spectroscopy

Stochastic averaging of quasi integrable and resonant Hamiltonian systems excited by fractional Gaussian noise with Hurst index 1/2

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Acta Mechanica Solida Sinica 2017年第1期30卷 11-19页

作者： q.F.lü M.l.Deng W.q.Zhu Department of Mechanics State Key Laboratory of Fluid Power and Mechatronic SystemsKey Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang University

A stochastic averaging method of quasi integrable and resonant Hamiltonian systems under excitation of fractional Gaussian noise （fGn） with the Hurst index 1/2 〈 H 〈 1 is proposed. First, the definition and the basic property of fGn and related fractional Brownian motion （iBm） are briefly introduced. Then, the averaged fractional stochastic differential equations （SDEs） for the first integrals and combinations of angle variables of the associated Hamiltonian systems are derived. The stationary probability density and statistics of the original systems are then obtained approximately by simulating the averaged SDEs numerically. An example is worked out to illustrate the proposed stochastic averaging method. It is shown that the results obtained by using the proposed stochastic averaging method and those from digital simulation of original system agree well.

关键词： quasi integrable and resonant Hamiltonian system Fractional Brownian motion Fractional Gaussian noise Stochastic averaging method Internal resonant

Kinetics of the reaction of OH radical with ethylfluoroacetate,ethyl 4,4,4-trifluorobutyrate,and butylfluoroacetate

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Journal of Environmental Sciences 2025年第5期151卷 273-283页

作者： Pedro l.lugo Vianni Straccia Mariano A.Teruel María B.Blanco laboratorio Universitario de química y Contaminación del Aire(l.U.q.C.A) Institute for Research in Physical Chemistry of Córdoba(I.N.F.I.Q.C.)Department of Physical ChemistryFaculty of Chemical SciencesNational University of CórdobaUniversity CityCórdoba 5000Argentina Institute for Atmospheric and Environmental Research University of WuppertalWuppertal DE-42097Germany

Kinetics of the gas-phase reactions of•OH radicals with a series of fluoroesters were studied for the first time at 298±3 K and atmospheric *** rate coefficients were determined by in situ FTIR spectroscopy in nitrogen and GC-FID in air to monitor the decay of reactants and *** following coefficient values(in 10^(−12)cm^(3)/(molecule•sec))were obtained for ethyl fluoroacetate(EFA),ethyl 4,4,4-trifluorobutyrate(ETB),and butyl fluoroacetate(BFA),respectively:k_(1)(EFA+OH)=1.15±0.25 by FTIR and 1.34±0.23 by GC-FID;k_(2)(ETB+OH)=1.61±0.36 by FTIR and 2.02±0.30 by GC-FID;k_(3)(BFA+OH)=2.24±0.37 by *** trends were developed and correlated with the number of CH_(3)and F substituents in the fluoroester,and structure-activity relationships(SARs)calculations were *** addition,the tropospheric lifetimes of EFA,ETB,and BFA upon degradation by OH radicals were calculated to be 9,6,and 5 days,respectively,indicating that these fluorinated compounds could have a possible regional effect from the emission *** small photochemical ozone creation potentials of 9,7,and 19 were estimated for EFA,ETB,and BFA,*** GlobalWarming Potentials(GWPs)for EFA,ETB,and BFA were calculated for different time *** a 20-year time horizon,the GWPs were 1.393,0.063,and 0.062,*** the case of a 100-year time horizon,the GWPs were 0.379,0.017,and 0.017,and for a 500-year time horizon,the GWPs were 0.108,0.005,and 0.005 for EFA,ETB,and BFA.

关键词： CFC replacements sinks in situ FTIR SAR Acidification potentials Greenhouse gases

Reliability of quasi integrable and non-resonant Hamiltonian systems under fractional Gaussian noise excitation

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Acta Mechanica Sinica 2020年第4期36卷 902-909页

作者： q.F.lu W.q.Zhu M.l.Deng Department of Mechanics State-Key Laboratory of Fluid Power and Mechatronic SystemsZhejiang UniversityHangzhou 310027China

The reliability of quasi integrable and non-resonant Hamiltonian system under fractional Gaussian noise(fGn)excitation is *** rather flat fGn power spectral density(PSD)in most part of frequency band,the fGn is innovatively regarded as a wide-band ***,the stochastic averaging method for quasi integrable Hamiltonian systems under wide-band noise excitation is applied to reduce 2n-dimensional original system into n-dimensional averaged ltd stochastic differential equations(SDEs).Reliability function and mean first passage time are obtained by solving the associated backward Kolmogorov equation and Pontryagin *** validity of the proposed procedure is tested by applying it to an example and comparing the numerical results with those from Monte Carlo simulation.

关键词： Reliability Fkst passage time quasi integrable and non-resonant Hamiltonian systems Fractional Gauss noise

Searching Radio Signals from Two Magnetars and a High-magnetic Field Pulsar and the Serendipitous Discovery of a New Radio Pulsar PSR J1935+2200

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Research in Astronomy and Astrophysics 2025年第1期25卷 110-115页

作者： lang Xie J.l.Han Z.l.Yang W.C.Jing D.J.Zhou W.q.Su Yi Yan Tao Wang Nan-Nan Cai P.F.Wang Chen Wang National Astronomical Observatories Chinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences National Key laboratory for Radio Astronomy Chinese Academy of Sciences

Magnetars are slowly rotating, highly magnetized young neutron stars that can show transient radio phenomena for radio pulses and fast radio bursts. We conducted radio observations from two magnetars SGR J1935+2154 and3XMM J185246.6+003317 and a high-magnetic field pulsar PSR J1846–0258 using the Five-hundred-meter Aperture Spherical radio Telescope（FAST）. We performed single pulse and periodicity searches and did not detect radio signals from them. From the piggyback data recorded by other FAST telescope beams when we observed the magnetar SGR 1935+2154, we serendipitously discovered a new radio pulsar, PSR J1935+2200. We carried out the follow-up observations and obtained the timing solution based on these new observations and the archive FAST data. PSR J1935+2200 is an isolated old pulsar, with a spin period of 0.91 s, a spin-period derivative of9.19 × 10-15s s-1, and a characteristic age of 1.57 Myr. It is a weak pulsar with a flux density of 9.8 μJy at1.25 GHz. Discovery of a new pulsar from the long FAST observations of 30 minutes implies that there may be more weak older pulsars in the Galactic disk to be discovered.

关键词： (stars:) pulsars: individual (PSR J1935+2200) stars: neutron

Deep view of composite SNR CTA1 with lHAASO in γ-rays up to 300 TeV

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Science China(Physics,Mechanics & Astronomy) 2025年

作者： Zhen Cao F.Aharonian Axikegu Y.X.Bai Y.W.Bao D.Bastieri X.J.Bi Y.J.Bi W.Bian A.V.Bukevich q.Cao W.Y.Cao Zhe Cao J.Chang J.F.Chang A.M.Chen E.S.Chen H.X.Chen liang Chen lin Chen long Chen M.J.Chen M.l.Chen q.H.Chen S.Chen S.H.Chen S.Z.Chen T.l.Chen Y.Chen N.Cheng Y.D.Cheng M.C.Chu M.Y.Cui S.W.Cui X.H.Cui Y.D.Cui B.Z.Dai H.l.Dai Z.G.Dai Danzengluobu X.q.Dong K.K.Duan J.H.Fan Y.Z.Fan J.Fang J.H.Fang K.Fang C.F.Feng H.Feng l.Feng S.H.Feng X.T.Feng Y.Feng Y.l.Feng S.Gabici B.Gao C.D.Gao q.Gao W.Gao W.K.Gao M.M.Ge T.T.Ge l.S.Geng G.Giacinti G.H.Gong q.B.Gou M.H.Gu F.l.Guo J.Guo X.l.Guo Y.q.Guo Y.Y.Guo Y.A.Han O.A.Hannuksela M.Hasan H.H.He H.N.He J.Y.He Y.He Y.K.Hor B.W.Hou C.Hou X.Hou H.B.Hu q.Hu S.C.Hu C.Huang D.H.Huang T.q.Huang W.J.Huang X.T.Huang X.Y.Huang Y.Huang Y.Y.Huang X.l.Ji H.Y.Jia K.Jia H.B.Jiang K.Jiang X.W.Jiang Z.J.Jiang M.Jin M.M.Kang I.Karpikov D.Khangulyan D.Kuleshov K.Kurinov B.B.li C.M.li Cheng li Cong li D.li F.li H.B.li H.C.li Jian li Jie li K.li S.D.li W.l.li W.l.li X.R.li Xin li Y.Z.li Zhe li Zhuo li E.W.liang Y.F.liang S.J.lin B.liu C.liu D.liu D.B.liu H.liu H.D.liu J.liu J.l.liu M.Y.liu R.Y.liu S.M.liu W.liu Y.liu Y.N.liu q.luo Y.luo H.K.lv B.q.Ma l.l.Ma X.H.Ma J.R.Mao Z.Min W.Mitthumsiri H.J.Mu Y.C.Nan A.Neronov K.C.Y.Ng l.J.Ou P.Pattarakijwanich Z.Y.Pei J.C.qi M.Y.qi B.q.qiao J.J.qin A.Raza D.Ruffolo A.Sáiz M.Saeed D.Semikoz l.Shao O.Shchegolev X.D.Sheng F.W.Shu H.C.Song Yu.V.Stenkin V.Stepanov Y.Su D.X.Sun q.N.Sun X.N.Sun Z.B.Sun J.Takata P.H.T.Tam q.W.Tang R.Tang Z.B.Tang W.W.Tian l.H.Wan C.Wang C.B.Wang G.W.Wang H.G.Wang H.H.Wang J.C.Wang Kai Wang Kai Wang l.P.Wang l.Y.Wang P.H.Wang R.Wang W.Wang X.G.Wang X.Y.Wang Y.Wang Y.D.Wang Y.J.Wang Z.H.Wang Z.X.Wang Zhen Wang Zheng Wang D.M.Wei J.J.Wei Y.J.Wei T.Wen C.Y.Wu H.R.Wu q.W.Wu S.Wu X.F.Wu Y.S.Wu S.q.Xi J.Xia G.M.Xiang D.X.Xiao G.Xiao Y.l.Xin Y.Xing D.R.Xiong Z.Xiong D.l.Xu R.F.Xu R.X.Xu W.l.Xu l.Xue D.H.Yan J.Z.Yan T.Yan C.W.Yang C.Y.Yang F.Yang F.F.Yang l.l.Yang M.J.Yang R.Z.Yang W.X.Yang Y.H.Yao Z.G.Yao l.q.Yin N.Yin X.H.You Z.Y.You Y.H Southwest Jiaotong University School of Astronomy and Space Science Nanjing University Center for Astrophysics Guangzhou University Tsung-Dao lee Institute & School of Physics and Astronomy Shanghai Jiao Tong University Institute for Nuclear Research of Russian Academy of Sciences Hebei Normal University University of Science and Technology of China lHAASO Collaboration State Key laboratory of Particle Detection and Electronics Key laboratory of Dark Matter and Space Astronomy & Key laboratory of Radio Astronomy Purple Mountain Observatory Chinese Academy of Sciences Research Center for Astronomical Computing Zhejiang laboratory Key laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences School of Physics and Astronomy Key laboratory of Particle Astrophysics & Experimental Physics Division & Computing Center Yunnan University Key laboratory of Cosmic Rays (Tibet University) Ministry of Education Department of Physics The Chinese University of Hong Kong Key laboratory of Radio Astronomy and Technology National Astronomical Observatories Chinese Academy of Sciences School of Physics and Astronomy (Zhuhai) & School of Physics (Guangzhou) & Sino-French Institute of Nuclear Engineering and Technology (Zhuhai) Sun Yat-sen University Institute of High Energy Physics Institute of Frontier and Interdisciplinary Science Shandong University APC Université Paris Cité CNRS/IN2P3 CEA/IRFU Observatoire de Paris Department of Engineering Physics & Department of Astronomy Tsinghua University School of Physics and Microelectronics Chinese Academy of Sciences Zhengzhou University Yunnan Observatories Chinese Academy of Sciences China Center of Advanced Science and Technology College of Physics Sichuan University School of Physics Peking University Guangxi Key laboratory for Relativistic Astrophysics School of Physical Science and Technology University of Chinese Academy of Sciences Guangxi University Department of Physics Faculty of Science Mahidol University Moscow Institute

The ultra-high-energy（UHE） gamma-ray source 1lHAASO J0007+7303u is positionally associated with the composite SNR CTA1 that is located at high Galactic latitude b ≈ 10.5°. This provides a rare opportunity to spatially resolve the component of the pulsar wind nebula（PWN） and supernova remnant（SNR） at UHE. This paper conducted a dedicated data analysis of 1lHAASO J0007+7303u using the data collected from December 2019 to July 2023. This source is well detected with significances of 21σ and 17σ at 8-100 TeV and >100 TeV, respectively. The corresponding extensions are determined to be 0.23°±0.03°and 0.17°±0.03°. The emission is proposed to originate from the relativistic electrons accelerated within the PWN of PSR J0007+7303. The energy spectrum is well described by a power-law with an exponential cutoff function dN/dE =（42.4 ± 4.1）(E/（20 TeV）)-2.31±0.11exp(-E/（110±25 TeV）) TeV-1cm-2s-1in the energy range from 8 to 300 TeV, implying a steady-state parent electron spectrum dNe/dEe∝(Ee/（100 TeV）)-3.13±0.16exp[(-Ee/（373±70 TeV）)2] at energies above ≈ 50 TeV. The cutoff energy of the electron spectrum is roughly equal to the expected current maximum energy of particles accelerated at the PWN terminal shock. Combining the X-ray and gamma-ray emission, the current space-averaged magnetic field can be limited to≈ 4.5 μG. To satisfy the multi-wavelength spectrum and the γ-ray extensions, the transport of relativistic particles within the PWN is likely dominated by the advection process under the free-expansion phase assumption.

关键词：

lHAASO detection of very-high-energy γ-ray emission surrounding PSR J0248+6021

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Science China(Physics,Mechanics & Astronomy) 2025年

We report the detection of an extended very-high-energy(VHE) γ-ray source coincident with the location of middle-aged(62.4 kyr) pulsar PSR J0248+6021, by using the lHAASO-WCDA data of live 796 d and lHAASO-KM2A data of live 1216d. A significant excess of γ-ray induced showers is observed both by WCDA in energy bands of 1-25 Te V and KM2A in energy bands of >25 TeV with 7.3σ and 13.5σ, respectively. The best-fit position derived through WCDA data is R.A. = 42.06°± 0.12°and Dec. = 60.24°± 0.13°with an extension of 0.69°±0.15°and that of the KM2A data is R.A.= 42.29°± 0.13°and Dec. =60.38°± 0.07°with an extension of 0.37°±0.07°. No clear extended multiwavelength counterpart of this lHAASO source has been found from the radio band to the GeV band. The most plausible explanation of the VHE γ-ray emission is the inverse Compton process of highly relativistic electrons and positrons injected by the pulsar. These electrons/positrons are hypothesized to be either confined within the pulsar wind nebula or to have already escaped into the interstellar medium, forming a pulsar halo.

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Observation of the γ-ray emission from W43 with lHAASO

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Science China(Physics,Mechanics & Astronomy) 2025年

In this paper, we report the detection of the very-high-energy (VHE, 100 Ge V100 TeV) γ-ray emissions from the direction of the young star-forming region W43, observed by the large High Altitude Air Shower Observation (lHAASO). The extended γ-ray source was detected with a significance of～16σby KM2A and～17σby WCDA, respectively. The angular extension of this γ-ray source is about 0.5 degrees, corresponding to a physical size of about 50pc. We discuss the origin of the γ-ray emission and possible cosmic ray acceleration in the W43 region using multi-wavelength data. Our findings suggest that W43 is likely another young star cluster capable of accelerating cosmic rays (CRs) to at least several hundred TeV.

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Influence of Fe Addition on Products of Self-Propagating High-Temperature Synthesis Reaction in 3Ti-Si-2C System

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稀有金属材料与工程 2009年第A03期38卷 113-118页

作者： Guan q l Wang H Y li S l Si W P Jiang q C Key laboratory of Automobile Materials of Ministry of Education Jilin University Changchun 130025 China

Influence of Fe addition on products of self-propagating high-temperature synthesis (SHS) reaction in 3Ti-Si-2C system was investigated in the present study. Without Fe addition, Ti5Si3 and TiC are the dominant phases along with a small amount of Ti3SiC2 phase and unreacted C left in the final products. As Fe content ranges from 10% to 30%, the products consist of TiC, Ti5Si3, Fe2Ti and unreacted C, but no trace of Ti3SiC2 phase is detected. Furthermore, the amounts of both Fe2Ti and C phases increase with Fe content increasing. Addition of Fe has a great effect on the reaction route and significantly restrains the formation of Ti3SiC2 during the combustion synthesis process, and therefore, the SHS is not an effective fabrication technique to synthesize the ternary Ti3SiC2 ceramic in either 3Ti-Si-2C or Fe-3Ti-Si-2C system. Besides, without Fe addition, Ti5Si3 presents as the coarse irregular appearance with an obviously sintered morphology. In contrast, the shape of Ti5Si3 exhibits more and more spherical (cobblestone-like) and the surface becomes increasingly smooth, because the amount of liquids formed during the SHS reaction increases with the increase of Fe content. On the other hand, with Fe content increasing from 0 to 30 wt.%, the particulate size of TiC decreases from more than 5 μm to 1 μm or less, mainly due to the fact that the combustion temperature decreases with the increase of Fe content in the preforms.

关键词：复合材料铁含量燃烧过程物理性能