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Assessment of the hazard of extreme low-temperature events over China in 2021

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Advances in Climate Change Research 2022年第6期13卷 811-818页

作者： ying-xian ZHANG Guo-Fu WANG China Meteorological Administration Climate Studies Key Laboratory Beijing 100081China National Climate Center China Meteorological AdministrationBeijing 100081China

In January 2021,an impressive extreme low-temperature event(ELTE)occurred in China,bringing record-breaking low temperatures to some *** comprehensive hazard and the overall situation of ELTEs in the whole of 2021 are still ***,the overview of ELTEs over the mainland in 2021 and their hazards were systematically reviewed and comprehensively evaluated by using an improved identification and assessment method,which can objectively determine the hazard levels of ELTEs and distinguish spatial differences in the hazard of a single event.A total of 20 ELTEs occurred in 2021;their intensity was remarkably higher than the climatology,while the impacted area and duration were lower than or near the climatology,indicating a normal *** general,the losses of low-temperature related disasters in 2021 were relatively less than the average loss in the past ten years,which is likely related to the low proportion of higher-than-moderately low events in the whole *** in 2021 had large impacts on Northwest,North and Northeast China and small impacts on the southeastern Qinghai-Tibet Plateau and western parts of Southwest *** and autumn had a higher-than-normal hazard index for ELTEs due to two high-hazard events in early-to-mid January and early-to-mid November,*** two high-hazard events showed different spatial *** former mainly affected central and eastern parts of ***,the latter mostly attacked central and western parts of China,especially resulting in high-hazard in parts of Xinjiang.

关键词： Extreme low-temperature events Hazard assessment China

Identification of winter long-lasting regional extreme low-temperature events in Eurasia and their variation during 1948—2017

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Advances in Climate Change Research 2021年第3期12卷 353-362页

作者： ZHANG ying-xian LIU Yan-Ju DING Yi-Hui Laboratory for Climate Studies National Climate CenterChina Meteorological AdministrationBeijing100081China

Compared with short-duration events,long-lasting regional extreme low-temperature events(RELTEs)often have more severe impacts on human societies due to the induced persistence and large geographic area of related weather and climate ***,an improved objective technique was applied to identify all long-lasting RELTEs in Eurasia from the winter of 1948/1949 to 2017/2018,followed by an in-depth discussion of its variation in terms of the annual frequency,duration,impacted area,mean intensity,maximum intensity,and a comprehensive *** RELTE lasting for 52 d in the winter of 2007/2008 exhibited the longest duration,largest impacted area,and a greatest comprehensive index,which induced extremely low temperatures for more than 20 d in Western Asia,Central Asia,and *** the past 70 winters,the frequency of long-lasting RELTEs decreased,especially after the late ***,the mean and maximum intensities and comprehensive index exhibited distinctly increasing *** indicators of winter long-lasting RELTEs had a similar inter-decadal fluctuation featured by two noticeable peaks occurring around 1970 and 2007,and a remarkable recovery was discovered in the period of late 1990s to mid-2010s,especially for the occurrence of super long-lasting ***,winter long-lasting RELTEs in Eurasia showed distinct trends under various decadal climate backgrounds,i.e.,a strong negative or weak positive trend in the accelerated warming period and conversely,a strong positive or weak negative trend in the wanning slowdown *** findings indicate that we should be alert of the similar future recovery of winter long-lasting RELTEs in Eurasia,which are likely to occur in the slowdown period of global warming.

关键词： Regional extreme low-temperature events Winter Long-lasting Eurasia Climate variation

In the THALES Trial, Past, Present, and Future Meet

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Neuroscience Bulletin 2021年第4期37卷 588-591页

作者： Zi-Xiao Li Xue-Wei Xie ying xian Vascular Neurology Department of NeurologyBeijing Tiantan HospitalCapital Medical UniversityBeijing100070China China National Clinical Research Center for Neurological Diseases Beijing100070China Chinese Institute for Brain Research Beijing100070China Department of Neurology Duke University Medical CenterDurhamNC27701USA

Patients with minor ischemic stroke or a high-risk transient ischemic attack (TIA) face a high risk of recurrent stroke or other vascular events. The risk is particularly high in the first few weeks after the index event. Dual antiplatelet therapy (DAPT),comprising clopidogrel and aspirin, is an effective strategy for reducing recurrence.

关键词： DAPT Patients aspirin

Enhanced formaldehyde sensitivity of two-dimensional mesoporous SnO_(2) by nitrogen-doped graphene quantum dots

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Rare Metals 2021年第6期40卷 1561-1570页

作者： Zhen-Lu Chen Ding Wang xian-ying Wang Jun-He Yang School of Materials Science and Engineering University of Shanghai for Science&TechnologyShanghai 200093China

Formaldehyde(HCHO) is widely known as an indoor air pollutant,and the monitoring of the gas has significant ***,most HCHO sensing materials do not have low detection limits and operate at high ***,two-dimensional(2D) mesoporous ultrathin SnO_(2) modified with nitrogen-doped graphene quantum dots(N-GQDs) was *** N-GQDs/SnO_(2) nanocomposite demonstrated high efficiency for HCHO *** the addition of 1.00 wt%N-GQDs,the response(Ra/Rg) of SnO_(2) gas sensor increased from 120 to 361 at 60℃ for the detection of 10×10^(-6) *** addition,the corresponding detection limit was as low as 10×10^(-9).Moreover,the sensor exhibited excellent selectivity and stability for the detection of *** enhanced sensing performance was attributed to both the large specific surface area of SnO_(2) and electron regulation of ***,this study presents a novel HCHO sensor,and it expands the research and application potential of GQDs nanocomposites.

关键词： Nitrogen-doped graphene quantum dots Formaldehyde sensor Two-dimensional SnO_(2) Nanocomposites

Microstructure and mechanical properties of TiN/AlN multilayers deposited by filtered vacuum arc deposition

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中国有色金属学会会刊：英文版 2004年第z1期14卷 234-237页

作者： ZHANG Xu ZHANG Hui-xing ZHANG Tong-he WU xian-ying Key Laboratory of Beam Technology and Material Modification of Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal UniversityBeijing Radiation Center Beijing 100875 China Key Laboratory of Beam Technology and Material Modification of Ministry of EducationInstitute of Low Energy Nuclear Physics Beijing Normal UniversityBeijing Radiation Center Beijing 100875 China Key Laboratory of Beam Technology and Material Modification of Ministry of EducationInstitute of Low Energy Nuclear Physics Beijing Normal UniversityBeijing Radiation Center Beijing 100875 China Key Laboratory of Beam Technology and Material Modification of Ministry of EducationInstitute of Low Energy Nuclear Physics Beijing Normal UniversityBeijing Radiation Center Beijing 100875 China

Nanometer TiN/AlN multilayers were prepared on silicon substrate by filtered vacuum arc *** structures of the nanometer TiN/AlN multilayer were studied by using X-ray diffraction. The 12 nm TiN/AlN multiplayer is composed of cubic TiN structure and hexagonal wurzite AlN structure, but the 2 nm period multilayer is composed of face centered cubic structure TiN and AlN with strong (200) texture. The surface roughness, hardness and elastic modulus of multilayer are dependent on the period of multilayer. The hardness of the TiN/AlN multilayers is higher than that suggested by a simple rule of mixture. The peaking hardness of nanometer TiN/AlN multilayers at period of 2 nm is about 42 GPa, much higher than that of 12 nm. The wear resistance of the nanometer TiN/AlN multilayers was also studied.

关键词： multilayer filtered arc nanometer wear

Effect of Postharvest UV-C Irradiation on Phenolic Compound Content and Antioxidant Activity of Tomato Fruit During Storage

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Journal of Integrative Agriculture 2012年第1期11卷 159-165页

作者： LIU Chang-hong CAI Lu-yun LU xian-ying HAN Xiao-xu ying Tie-jin Department of Food Science and Nutrition College of Biosystem Engineering and Food ScienceZhejiang UniversityHangzhou 310058P.R.China

Mature-green tomato fruit （Solanum lycopersicum cv. Zhenfen 202） were exposed to different UV-C irradiation at 2, 4, 8, and 16 kJ m-2 and then stored under the dark at 14°C and 95% relative humidity （RH） for 35 d. Of these four doses, UV-C irradiation at 4 and 8 kJ m-2 significantly increased total phenolic contents in present tomato fruit by 21.2 and 20.2%, respectively. Furthermore, UV-C irradiation at 4 or 8 kJ m-2 promoted the accumulation of total flavonoids and increased the antioxidant activity. 2 or 16 kJ m-2 UV-C irradiation also enhanced antioxidant activity, but to a lesser extent. Seven phenolic compounds, viz., gallic acid, （＋）-catechin, chlorogenic acid, cafferic acid, syringic acid, p-coumaric acid, and quercetin in tomato fruit were identified and quantified by HPLC. Gallic acid was the major phenolic compound in tomato fruit and significantly correlated with antioxidant activity. 4 or 8 kJ m-2 UV-C irradiation significantly increased the contents of gallic acid, chlorogenic acid, syringic acid, p-coumaric acid, and quercetin. The optimum dose of UV-C irradiation in terms of increased phenolic compound content and enhanced Antioxidant activity was determined to be 4 or 8 kJ m-2.

关键词： tomato postharvest UV-C irradiation storage antioxidant activity phenolic compounds

Comprehensive evaluation of surface air temperature reanalysis over China against urbanization-bias-adjusted observations

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Advances in Climate Change Research 2021年第6期12卷 783-794页

作者： ZHANG Si-Qi REN Guo-Yu REN Yu-Yu ZHANG ying-xian XUE Xiao-ying Department of Atmospheric Science School of Environmental StudiesChina University of GeosciencesWuhan430074China Laboratory for Climate Studies National Climate CenterChina Meteorological AdministrationBeijing100081China Key Laboratory for Cloud Physics China Meteorological AdministrationBeijing100081China

The reanalysis datasets (CRA40) have now been developed in China Meteorological Administration. We aim to compare the differences in surface air temperature (SAT) between observational that has been adjusted for urbanization bias and reanalysis data (NCEPV1, NCEPV2, ERA5, CFSR, MERRA, JRA55, 20CRV3 and CRA40) over China's Mainland during 1961–2015. The main results are presented as follows. The correlation and standard deviation between the reanalysis data and observations exhibit highly consistent interannual variability and dispersion, with the interannual SAT variability in JRA55 being closest to the observations for 1961–2015 and that of ERA5 for 1979–2015;the dispersions of 20CRV3 is most consistent with the observations for 1961–2015 and that of NCEPV1 for 1979–2015. Although annual mean SAT of the reanalysis is generally 0–2.0 ℃ lower than the observations, the bias in the SAT climatology of 20CRV3 is the least for 1961–2015 in all reanalysis datasets and that of CRA40 is the least for 1979–2015. The trends of NCEPV1 is closer to the observations than other reanalysis for 1961–2015 and that of 20CRV3 for 1979–2015. The biases in terms of interannual variability, dispersion, climatology, and linear trend are increase with altitude. Overall, in terms of the similarity of multiple measures to the urbanization bias-adjusted observations, JRA55 and CRA40 show the best performances for the periods 1961–2015 and 1979–2015 respectively in reproducing various aspects of climatological and climate change features in China's Mainland.

关键词： Temperature Reanalysis data Urbanization bias Adjusted observations Comparison Evaluation China

Determination of jumps for functions via derivative Gabor series

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Applied Mathematics(A Journal of Chinese Universities) 2009年第2期24卷 191-199页

作者： ZHOU ying-ying SHI xian-liang College of Mathematics and Computer Science, Hunan Normal University,Changsha 410081,China College of Mathematics and Computer Science Hunan Normal University Changsha 410081 China

Recently, Shi xianliang and Hu Lan published the method of concentration factors for determination of jumps of functions via MCM conjugate wavelets. Usually, it is difficult to calculate the Hilbert transform of general window functions. The aim of this paper is to discuss determination of jumps for functions based on derivative Gabor series. The results will simplify the calculation of jump values.

关键词： jumps Gabor series derivative

Fluid Model Modulated by an M/M/1 Working Vacation Queue with Negative Customer

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Acta Mathematicae Applicatae Sinica 2018年第2期34卷 404-415页

作者： Xiu-li XU xian-ying WANG Xiao-feng SONG Xiao-qing LI College of Science Yanshan University

This paper investigates a fluid model driven by an M/M/1 queue with working vacations and RCE （Removal of customer in the end） policy of negative customer. In the external environment, the negative customer is not served by the server and only removes the positive customer in the end one-to-one. We establish a fluid flow model based on this stochastic process, and obtain the mean buffer content and the probability of empty buffer for this fluid queue using the LT （Laplace transform） method. Moreover, several special cases of the model here are obtained. Finally, some numerical examples are presented to demonstrate the effects of parameters on the performance indices of the fluid model.

关键词： fluid model negative customer RCE (Removal of customer in the end) policy buffer content LT(Laplace transform)