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The characteristics and future projections of fire danger in the areas around mega-city based on meteorological data–a case study of Beijing

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Frontiers of Earth Science 2024年第3期18卷 637-648页

作者： Mengxin BAI Wupeng DU Zhixin HAO Liang ZHANG pei XING Beijing Municipal Climate Center Beijing Meteorological ServiceBeijing 100089China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

It is crucial to investigate the characteristics of fire danger in the areas around Beijing to increase the accuracy of fire danger monitoring,forecasting,and *** meteorological data from 17 national meteorological stations in the areas around Beijing from 1981−2021,this study calculated the fire weather index(FWI)and analyzed its spatiotemporal *** was found that the high and low fire danger periods were in April−May and July−August,with spatial patterns of“decrease in the northwest−increase in the southeast”and a significant increase throughout the areas around Beijing,***,the contributions of different meteorological factors were quantified by the multiple regression *** found that during the high fire danger period,the northern and southern parts were affected by precipitation and minimum relative humidity,***,most areas were influenced by wind speed during the low fire danger ***,comparing with the FWI characteristics under different SSP scenarios,we found that the FWI decreased during high fire danger period and increased during low fire danger period under different SSP scenarios(i.e.,SSP245,SSP585)for periods of 2021−2050,2071−2100,2021−2100,except for SSP245 in 2071−2100 with an increasing trend both in high and low fire danger *** study implies that there is a higher probability of FWI in the low fire danger period,threatening the ecological environment and human ***,it is necessary to enhance research on fire danger during the low fire danger period to improve the ability to predict summer fire danger.

关键词： meteorological data-based fire danger areas around Beijing climate characteristics SSP scenarios

A Novel Ni‑Free Zr‑Based Bulk Metallic Glass with High Glass Forming Ability,Corrosion Resistance and Thermal Stability

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Chinese Journal of Mechanical Engineering 2020年第4期33卷 168-174页

作者： yu Luo yidong Jiang pei Zhang Xin Wang Haibo Ke Pengcheng Zhang Institute of Materials China Academy of Engineering PhysicsJiangyou 621907China

Zr-based Bulk metallic glasses exhibit incredible corrosion resistance and glass forming ability,however,these properties need further enhancement to meet the practical *** this study,Zr63Fe2.5Cu23Al11.5,a new type of Zr-based bulk metallic glass was *** polarization techniques were used to measure the corrosion resistance of this ***,crystallization behavior and kinetics of Zr63Fe2.5Cu23Al11.5 bulk metallic glass were investigated by using differential scanning calorimetry of non-isothermal *** and Ozawa methods were used for calculating activation energies of crystallization and the mechanism of crystallization was analyzed by Johnson-Mehl-Avrami-Kolmogorow *** results suggest that this specified metallic glass system possesses a relatively high thermal stability and glass forming ***,the crystallization procedure is mainly dominated by nucleation with an increasing *** study demonstrates that the slight composition adjustment of Zr-Fe-Cu-Al system bulk metallic glass can make a considerable contribution to higher glass forming and thermal stability as well as corrosion resistance.

关键词： Zr-based BMG Glass forming ability Corrosion resistance Thermal stability Crystallization behavior

Separation of galena and chalcopyrite using the difference in their surface acid corrosion characteristics

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International Journal of Minerals,Metallurgy and Materials 2023年第11期30卷 2157-2168页

作者： Haiyun Xie Jialing Chen pei Zhang Likun Gao Dianwen Liu Luzheng Chen Faculty of Land and Resources Engineering Kunming University of Science and TechnologyKunming 650093China yunnan Key Laboratory of Green Separation and Enrichment of Strategic Mineral Resources Kunming 650093China

Galena(PbS)and chalcopyrite(CuFeS_(2))are sulfide minerals that exhibit good floatability ***,efficiently separating them via common flotation is ***,a new method of surface sulfuric acid corrosion in conjunction with flotation separation was proposed,and the efficient separation of galena and chalcopyrite was successfully *** angle test results showed a substantial decrease in surface contact angle and a selective inhibition of surface floatability for corroded ***,the contact angle and floatability of corroded chalcopyrite remained almost *** electron microscope results confirmed that sulfuric acid corrosion led to the formation of a dense oxide layer on the galena surface,whereas the chalcopyrite surface remained unaltered.X-ray photoelectron spectroscopy results showed that the chemical state of S^(2-)on the surface of corroded galena was oxidized to SO_(4)^(2-).A layer of hydrophilic PbSO4was formed on the surface,leading to a sharp decrease in galena ***,new hydrophobic CuS_(2),CuS,and Cu_(1-x)Fe_(1-y)S_(2-z)species exhibiting good floatability were generated on the chalcopyrite ***,theoretical analysis results were further verified by corrosion–flotation separation *** galena–chalcopyrite mixture was completely separated via flotation separation under appropriate corrosion acidity,corrosion temperature,and corrosion time.A novel approach has been outlined in this study,providing potential applications in the efficient separation of refractory copper–lead sulfide ore.

关键词： surface acid corrosion galena chalcopyrite flotation separation efficiency

Breakdown of Energy Equipartition in Vibro-Fluidized Granular Media in Micro-Gravity

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Chinese Physics Letters 2012年第7期29卷 160-163页

作者： CHEN yan-pei Pierre Evesque HOU Mei-ying Key Laboratory of Soft Matter Physics Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190 Lab MSSMat Ecole Centrale de ParisUMR 8579 CNRS92295 Châtenay-Malabry CedexFrance

We present a micro-gravity experimental study of intermediate number density vibro-fluidized inelastic spheres in a rectangular *** velocity distributions are investigated,and are found to deviate measurably from a symmetric distribution for the velocity component of the vibrating direction when dividing particles along the vibration direction into several *** feature does not exist in the molecular *** further study the hydrodynamic profiles of pressures p and temperatures T in positive and negative components,such as p+y and p-y and T+y and T-y,in accordance with the sign of velocity components of the vibrating *** vibration direction,granular media are found to be not only inhomogeneous and anisotropic,but also different greatly in positive and negative *** equipartition breaks down in this case.

关键词： partition vibrating dividing

Mrakia psychrophila ***.,a new species isolated from Antarctic soil

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2007年第4期8卷 260-265页

作者： XIN Ming-xiu ZHOU pei-jin College of Life Sciences Beijing Normal University Beijing 100875 China Institute of Microbiology Academia Sinica Beijing 100080 China

The yeast strain （y18） was isolated from a soil sample collected from Fildes Peninsula, Antarctica. The strain is a psychrophilic yeast with optimum and maximum growth temperatures of 10 ℃ and 18 ℃, respectively. Teliospores were formed after 7 d on malt agar, when the germination of teliospores was observed. Both inositol and D-glucuronate were assimilated. Positive results of the DBB （diazonium blue B） color reaction, urease test, and starch formation were observed. The major CoQ is Qs. All results indicated that y18 belongs to the genes of Mrakia. The 18S rDNA sequence analyses showed that y18 is closely related to Mrakiafrigida. DNA-DNA relatedness study, and some biochemistry characteristics indicated that y18 represents a new species for which Mrakia psychrophila sp. nov. is proposed.

关键词： Mrakiapsychrophila Psychrophilic yeast 18S rDNA sequence Teliospores

Computational Model of Edge Effects in Graphene Nanoribbon Transistors

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Nano Research 2008年第5期1卷 395-402页

作者： pei Zhao Mihir Choudhury Kartik Mohanram Jing Guo Department of Electrical and Computer Engineering University of FloridaGainesvilleFL 32611USA Department of Electrical and Computer Engineering Rice UniversityHoustonTX 77005USA

We present a semi-analytical model incorporating the effects of edge bond relaxation,the third nearest neighbor interactions,and edge scattering in graphene nanoribbon fi eld-effect transistors(GNRFETs)with armchair-edge GNR(AGNR)*** carbon nanotubes(CNTs)which do not have edges,the existence of edges in the AGNRs has a signifi cant effect on the quantum capacitance and ballistic I V characteristics of *** an AGNR with an index of m=3p,the band gap decreases and the ON current increases whereas for an AGNR with an index of m=3p+1,the quantum capacitance increases and the ON current *** effect of edge scattering,which reduces the ON current,is also included in the model.

关键词： Graphene nanoribbon field-effect transistor edge bond relaxation third nearest neighbor interaction edge scattering

An Enhanced Adaptive Differential Evolution Approach for Constrained Optimization Problems

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Computer Modeling in Engineering & Sciences 2023年第9期136卷 2841-2860页

作者： Wenchao yi Zhilei Lin yong Chen Zhi pei Jiansha Lu College of Mechanical Engineering Zhejiang University of TechnologyHangzhou310023China

Effective constrained optimization algorithms have been proposed for engineering problems *** is common to consider constraint violation and optimization algorithm as two separate *** this study,a pbest selection mechanism is proposed to integrate the current mutation strategy in constrained optimization *** on the improved pbest selection method,an adaptive differential evolution approach is proposed,which helps the population jump out of the infeasible *** all the individuals are infeasible,the top 5%of infeasible individuals are *** addition,a modified truncatedε-level method is proposed to avoid trapping in infeasible *** proposed adaptive differential evolution approach with an improvedεconstraint processmechanism(IεJADE)is examined on CEC 2006 and CEC 2010 constrained benchmark function ***,a standard IEEE-30 bus test system is studied on the efficiency of the Iε*** numerical analysis verifies the IεJADE algorithm is effective in comparisonwith other effective algorithms.

关键词： pbest selection mechanism adaptive differential evolution εconstrained method

Hepatitis C virus-induced prion protein expression facilitates hepatitis C virus replication

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Virologica Sinica 2017年第6期32卷 503-510页

作者： Huixia Zhang Shanshan Gao Rongjuan pei Xinwen Chen Chaoyang Li State Key Laboratory of Virology Center for Molecular Virology Wuhan Institute of VirologyChinese Academy of SciencesWuhan 430071China University of the Chinese Academy of Sciences Beijing 100000China

Hepatitis C virus(HCV) infects approximately 180 million people worldwide. Significant progress has been made since the establishment of in vitro HCV infection models in cells. However, the replication of HCV is complex and not completely understood. Here, we found that the expression of host prion protein(Pr P) was induced in an HCV replication cell model. We then showed that increased Pr P expression facilitated HCV genomic replication. Finally, we demonstrated that the KKRPK motif on the N-terminus of Pr P bound nucleic acids and facilitated HCV genomic replication. Our results provided important insights into how viruses may harness cellular protein to achieve propagation.

关键词： hepatitis C virus(HCV) NS3 NS5B prion protein(PrP)

Removing phosphorus from aqueous solutions by using iron- modified corn straw biochar

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Frontiers of Environmental Science & Engineering 2015年第6期9卷 1066-1075页

作者： Fenglin LIU Jiane ZUO Tong CHI pei WANG Bo yANG State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing 100084 China

Iron-modified corn straw biochar was used as an adsorbent to remove phosphorus from agricultural runoff. When agricultural runoffs with a total phosphorus （TP） concentration of 1.86 mg.L-1 to 2.47 mg.L-1 were filtered at a hydraulic retention time of 2 h through a filtration column packed with the modified biochar, a TP removal efficiency of over 99% and an effluent TP concentration of less than 0.02mg.L-1 were achieved. The isotherms of the phosphorus adsorption by the modified biochar fitted the Freundlich equation better than the Langmuir equation. The mechanism of the phosphorus adsorbed by the modified biochar was analyzed by using various technologies, i.e. scanning electron microscopy （SEM）, X-ray diffraction （XRD） analysis, X-ray photoelectron spectroscopy （XPS）, and Fourier transform infrared spectroscopy （FTIR）. The results indicated that the surface of the modified biochar was covered by small iron granules, which were identified as Fe304. The results also showed that new iron oxides were formed on the surface of the modified biochar after the adsorption of phosphorus. Moreover, new bonds of Fe- O-P and P-C were found, which suggested that the new iron oxides tend to be Fe5（PO4）4（OH）3. Aside from removing phosphorus, adding the modified biochar into soil also improved soil productivity. When the modified biochar-to-soil rate was 5%, the stem, root, and bean of broad bean plants demonstrated increased growth rates of 91%, 64%, and 165%, respectively.

关键词： iron-modified biochar phosphorus removal,agricultural waste agricultural runoff