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60篇 您的检索式:作者名="Xiangwen Liu"
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1Performance of the Seasonal Forecasting of the Asian Summer Monsoon by BCC_CSM1.1(m)显示文摘This paper provides a comprehensive assessment of Asian summer monsoon prediction skill as a function of lead time and its relationship to sea surface temperature prediction using the seasonal hindcasts of the Beijing Climate Center Climate System Model, BCC CSM1.1(m). For the South and Southeast Asian summer monsoon, reasonable skill is found in the model's forecasting of certain aspects of monsoon climatology and spatiotemporal variability. Nevertheless, deficiencies such as significant forecast errors over the tropical western North Pacific and the eastern equatorial Indian Ocean are also found. In particular, overestimation of the connections of some dynamical monsoon indices with large-scale circulation and precipitation patterns exists in most ensemble mean forecasts, even for short lead-time forecasts.Variations of SST, measured by the first mode over the tropical Pacific and Indian oceans, as well as the spatiotemporal features over the Ni no3.4 region, are overall well predicted. However, this does not necessarily translate into successful forecasts of the Asian summer monsoon by the model. Diagnostics of the relationships between monsoon and SST show that difficulties in predicting the South Asian monsoon can be mainly attributed to the limited regional response of monsoon in observations but the extensive and exaggerated response in predictions due partially to the application of ensemble average forecasting methods. In contrast, in spite of a similar deficiency, the Southeast Asian monsoon can still be forecasted reasonably, probably because of its closer relationship with large-scale circulation patterns and El Nino–Southern Oscillation.LIU Xiangwen WU Tongwen YANG Song JIE Weihua NIE Suping LI Qiaoping CHENG Yanjie LIANG Xiaoyun 2015Advances in Atmospheric Sciences2015,32,8:25
2Au/LaVO_(4)Nanocomposite:Preparation,Characterization,and Catalytic Activity for CO Oxidation显示文摘The size of the gold particles is a very important parameter to get active catalysts.This paper reports a novel colloidal deposition method to prepare Au/LaVO_(4)nanocomposite catalyst with monodispersed Au colloids and uniform LaVO_(4)nanoplates in nonpolar solvent.Monodispersed Au colloids with tunable size(such as 2,5,7,11,13,and 16 nm)and LaVO_(4)nanocrystals with well-defi ned shapes were pre-synthesized assisted with oleic acid/amine.During the following immobilization process,the particle size and shape of Au and LaVO_(4)were nearly preserved.As-prepared Au/LaVO_(4)nanocomposite showed high catalytic activity for CO oxidation at room temperature.Since sizes of gold particles were well-defi ned before the immobilization process,size effect of gold particles was easy to be investigated and the results show that 5-nm Au/LaVO_(4)nanocomposite has the highest activity for CO oxidation.This synthetic method can be extended further for the preparation of other composite nanomaterials.Junfeng Liu Wei Chen Xiangwen Liu Kebin Zhou Yadong Li 2008Nano Research2008,1,1:16
3Effect of Process Parameters of Microwave Assisted Extraction (MAE) on Polysaccharides Yield from Pumpkin显示文摘Process parameters of microwave assisted extraction (MAE) of the polysaccharides from pumpkin viz. extraction temperature, time and liquid-solid ratio were studied by using single factor and response surface methodology method. The results showed that the liquid-solid ratio was the most important factor in polysaccharides yield, followed by extraction time, and the extraction temperature was the least important factor. The optimum microwave assisted extraction conditions for the highest polysaccharides yield from pumpkin (16.76%±0.38%) were obtained by using the response surface methodology with extraction time of 29 min, an extraction temperature of 79℃ and a liquid-solid ratio of 22 mL · g-1. Validation experiment result well agreed with predicted value.ZHENG Xianzhe YIN Fangping LIU Chenghai XU Xiangwen 2011Journal of Northeast Agricultural University(English Edition)2011,18,2:13
4Generation and Photocatalytic Activities of Bi@Bi2O3 Microspheres显示文摘合成 Bi@Bi2O3 microspheres 经由一条帮助微波的 solvothermal 线路被综合了。Bi@Bi2O3 microspheres 在范围有狭窄的尺寸分布 1.22.8 公里。葡萄糖作为 reductant 被选择,是的 BiCl3 铋来源,和乙烯乙二醇(例如) 作为在合成系统的溶剂。同样综合的样品被X光检查衍射( XRD )描绘,拉曼光谱学,X光检查光电子光谱学( XPS ),扫描电子显微镜学( SEM ),传播电子显微镜学( TEM ),粒子直径分发,精力散X光检查光谱学(版本),紫外可见(紫外力)光谱学,并且光致发光( PL )光谱学。Bi@Bi2O3 microspheres 的 photocatalytic 活动被玫瑰精 B (RhB ) 和甲基橘子(瞬间) 染料的 photodegradation 在紫外轻照耀下面评估。降级面对同样综合的 Bi@Bi2O3 microspheres 在 4 h 反应以后为瞬间为 RhB 和 100% 到达了 96.6% 。Xiangwen Liu Huaqiang Cao Jiefu Yin 2011Nano Research2011,4,5:11
5Application of artificial neural networks in global climate change and ecological research:An overview显示文摘Fields that employ artificial neural networks(ANNs)have developed and expanded continuously in recent years with the ongoing development of computer technology and artificial intelligence.ANN has been adopted widely and put into practice by research-ers in light of increasing concerns over ecological issues such as global warming,frequent El Nio-Southern Oscillation(ENSO)events,and atmospheric circulation anomalies.Limitations exist and there is a potential risk for misuse in that ANN model pa-rameters require typically higher overall sensitivity,and the chosen network structure is generally more dependent upon individ-ual experience.ANNs,however,are relatively accurate when used for short-term predictions;despite global climate change re-search favoring the effects of interactions as the basis of study and the preference for long-term experimental research.ANNs remain a better choice than many traditional methods when dealing with nonlinear problems,and possesses great potential for the study of global climate change and ecological issues.ANNs can resolve problems that other methods cannot.This is especially true for situations in which measurements are difficult to conduct or when only incomplete data are available.It is anticipated that ANNs will be widely adopted and then further developed for global climate change and ecological research.LIU ZeLin PENG ChangHui XIANG WenHua TIAN DaLun DENG XiangWen ZHAO MeiFang 2010Chinese Science Bulletin2010,55,34:9
6Relationships between Interannual and Intraseasonal Variations of the Asian–Western Pacific Summer Monsoon Hindcasted by BCC CSM 1.1(m)显示文摘Using hindcasts of the Beijing Climate Center Climate System Model, the relationships between interannual variability(IAV) and intraseasonal variability(ISV) of the Asian–western Pacific summer monsoon are diagnosed. Predictions show reasonable skill with respect to some basic characteristics of the ISV and IAV of the western North Pacific summer monsoon(WNPSM) and the Indian summer monsoon(ISM). However, the links between the seasonally averaged ISV(SAISV) and seasonal mean of ISM are overestimated by the model. This deficiency may be partially attributable to the overestimated frequency of long breaks and underestimated frequency of long active spells of ISV in normal ISM years, although the model is capable of capturing the impact of ISV on the seasonal mean by its shift in the probability of phases.Furthermore, the interannual relationships of seasonal mean, SAISV, and seasonally averaged long-wave variability(SALWV; i.e., the part with periods longer than the intraseasonal scale) of the WNPSM and ISM with SST and low-level circulation are examined. The observed seasonal mean, SAISV, and SALWV show similar correlation patterns with SST and atmospheric circulation, but with different details. However, the model presents these correlation distributions with unrealistically small differences among different scales, and it somewhat overestimates the teleconnection between monsoon and tropical central-eastern Pacific SST for the ISM, but underestimates it for the WNPSM, the latter of which is partially related to the too-rapid decrease in the impact of El Nino–Southern Oscillation with forecast time in the model.LIU Xiangwen WU Tongwen YANG Song LI Qiaoping CHENG Yanjie LIANG Xiaoyun FANG Yongjie JIE Weihua NIE Suping 2014Advances in Atmospheric Sciences2014,31,5:9
7Solute-homogenization model and its experimental verification in Mg-Gd-based alloys显示文摘Composition homogenization in solid solution is important for industrial alloys. In the present work, a solute homogenization model is proposed based on the chemical short-range-order tendency in Mg-Gdbased alloys. After a calculation using the cluster-plus-glue-atom model, the stable Mg-Gd structural unit is derived, [Gd-Mg12]Mg6, where one solute Gd is nearest-neighbored with twelve Mg atoms to form the characteristic hcp cluster [Gd-Mg12] and this cluster is matched with six Mg glue atoms. Such a local unit is then mixed with [Mg-Mg12]Mg3, the stable unit for pure Mg. Assuming that the Gd-containing units are arranged in fcc-or bcc-like lattice points and the Mg units in their octahedral interstices, three proportions between the two units are obtained, 1:1, 2:3, and 1:3, which constitute three solute homogenization modes. The prevailing Mg-Gd-based alloys are consequently classified into three groups, respectively exemplified by GW103 K(Mg-10 Gd-3 Y-0.4 Zr, wt%), GW83 K(Mg-8 Gd-3 Y-0.4 Zr), and GW63 K(Mg-6 Gd-3 Y-0.4 Zr). Mg-Gd-Y-Zr alloys were designed following the model(where Y and Zr were also added in substitution for Gd) and prepared by permanent-mould casting. According to their mechanical properties,the 1:3 alloy(Mg-5.9 Gd-1.6 Y-0.4 Zr) shows the best comprehensive properties(ultimate tensile strength305 MPa, yield strength 186 MPa, elongation 9.0%) in solution plus ageing state.Shengnan Qian Chuang Dong Tianyu Liu Ying Qin Qing Wang Yujuan Wu Lidong Gu Jianxin Zou Xiangwen Heng Liming Peng Xiaoqin Zeng 2018Journal of Materials Science & Technology2018,34,7:6
8Review on the Relationship Between Liquid Aerospace Fuel Composition and Their Physicochemical Properties显示文摘The development of advanced air transportation has raised new demands for high-performance liquid hydrocarbon fuels.However,the measurement of fuel properties is time-consuming,cost-intensive,and limited to the operating conditions.The physicochemical properties of aerospace fuels are directly infl uenced by chemical composition.Thus,a thorough investigation should be conducted on the inherent relationship between fuel properties and composition for the design and synthesis of high-grade fuels and the prediction of fuel properties in the future.This work summarized the eff ects of fuel composition and hydrocarbon molecular structure on the fuel physicochemical properties,including density,net heat of combustion(NHOC),low-temperature fl uidity(viscosity and freezing point),fl ash point,and thermal-oxidative stability.Several correlations and predictions of fuel properties from chemical composition were reviewed.Additionally,we correlated the fuel properties with hydrogen/carbon molar ratios(n H/C)and molecular weight(M).The results from the least-square method implicate that the coupling of H/C molar ratio and M is suitable for the estimation of density,NHOC,viscosity and eff ectiveness for the design,manufacture,and evaluation of aviation hydrocarbon fuels.Xiaoyu Wang Tinghao Jia Lun Pan Qing Liu Yunming Fang Ji-Jun Zou Xiangwen Zhang 2021Transactions of Tianjin University2021,27,2:6
9Improvement of 6–15 Day Precipitation Forecasts Using a Time-Lagged Ensemble Method显示文摘A time-lagged ensemble method is used to improve 6–15 day precipitation forecasts from the Beijing Climate Center Atmospheric General Circulation Model, version 2.0.1. The approach averages the deterministic predictions of precipitation from the most recent model run and from earlier runs, all at the same forecast valid time. This lagged average forecast(LAF) method assigns equal weight to each ensemble member and produces a forecast by taking the ensemble mean. Our analyses of the Equitable Threat Score, the Hanssen and Kuipers Score, and the frequency bias indicate that the LAF using five members at time-lagged intervals of 6 h improves 6–15 day forecasts of precipitation frequency above 1 mm d-1and 5 mm d-1in many regions of China, and is more effective than the LAF method with selection of the time-lagged interval of 12 or 24 h between ensemble members. In particular, significant improvements are seen over regions where the frequencies of rainfall days are higher than about 40%–50% in the summer season; these regions include northeastern and central to southern China, and the southeastern Tibetan Plateau.JIE Weihua WU Tongwen WANG Jun LI Weijing LIU Xiangwen 2014Advances in Atmospheric Sciences2014,31,2:4
10Induction of Wnt signaling antagonists and p21-activated kinase enhances cardiomyocyte proliferation during zebrafish heart regeneration显示文摘Heart regeneration occurs by dedifferentiation and proliferation of pre-existing cardiomyocytes(CMs).However,the signaling mechanisms by which injury induces CM renewal remain incompletely understood.Here,we find that cardiac injury in zebrafish induces expression of the secreted Wnt inhibitors,including Dickkopf 1(Dkkl),Dkk3,secreted Frizzled-related protein 1(sFrpl),and sFrp2,in cardiac tissue adjacent to injury sites.Experimental blocking of Wnt activity via Dkkl overexpression enhances CM proliferation and heart regeneration,whereas ectopic activation of Wnt8 signaling blunts injury-induced CM dedifferentiation and proliferation.Although Wnt signaling is dampened upon injury,the cytoplasmic β-catenin is unexpectedly increased at disarrayed CM sarcomeres in myocardial wound edges.Our analyses indicated that p21-activated kinase 2(Pak2)is induced at regenerating CMs,where it phosphorylates cytoplasmic β-catenin at Ser 675 and increases its stability at disassembled sarcomeres.Myocardial-specific induction of the phospho-mimeticβ-catenin(S675E)enhances CM dedifferentiation and sarcomere disassembly in response to injury.Conversely,inactivation of Pak2 kinase activity reduces the Ser 675-phosphorylatedβ-catenin(pS675-β-catenin)and attenuates CM sarcomere disorganization and dedifferentiation・Taken together,these findings demonstrate that coordination of Wnt signaling inhibition and Pak2/pS675-βYatenin signaling enhances zebrafish heart regeneration by supporting CM dedifferentiation and proliferation.Xiangwen Peng Kaa Seng Lai Peilu She Junsu Kang Tingting Wang Guobao Li Yating Zhou jianjian Sun Daqing Jin Xiaolei Xu Lujian Liao Jiandong Liu Ethan Lee Kenneth D.Poss Tao P.Zhong 2021Journal of Molecular Cell Biology2021,13,1:3
11A Strategy for Merging Objective Estimates of Global Daily Precipitation from Gauge Observations, Satellite Estimates, and Numerical Predictions显示文摘This paper describes a strategy for merging daily precipitation information from gauge observations, satellite estimates(SEs), and numerical predictions at the global scale. The strategy is designed to remove systemic bias and random error from each individual daily precipitation source to produce a better gridded global daily precipitation product through three steps.First, a cumulative distribution function matching procedure is performed to remove systemic bias over gauge-located land areas. Then, the overall biases in SEs and model predictions(MPs) over ocean areas are corrected using a rescaled strategy based on monthly precipitation. Third, an optimal interpolation(OI)–based merging scheme(referred as the HL-OI scheme)is used to combine unbiased gauge observations, SEs, and MPs to reduce random error from each source and to produce a gauge—satellite–model merged daily precipitation analysis, called BMEP-d(Beijing Climate Center Merged Estimation of Precipitation with daily resolution), with complete global coverage. The BMEP-d data from a four-year period(2011–14) demonstrate the ability of the merging strategy to provide global daily precipitation of substantially improved quality.Benefiting from the advantages of the HL-OI scheme for quantitative error estimates, the better source data can obtain more weights during the merging processes. The BMEP-d data exhibit higher consistency with satellite and gauge source data at middle and low latitudes, and with model source data at high latitudes. Overall, independent validations against GPCP-1DD(GPCP one-degree daily) show that the consistencies between BMEP-d and GPCP-1DD are higher than those of each source dataset in terms of spatial pattern, temporal variability, probability distribution, and statistical precipitation events.Suping NIE Tongwen WU Yong LUO Xueliang DENG Xueli SHI Zaizhi WANG Xiangwen LIU Jianbin HUANG 2016Advances in Atmospheric Sciences2016,33,7:3
12Sub-seasonal to Seasonal Hindcasts of Stratospheric Sudden Warming by BCC_CSM1.1(m):A Comparison with ECMWF显示文摘This study focuses on model predictive skill with respect to stratospheric sudden warming(SSW) events by comparing the hindcast results of BCC_CSM1.1(m) with those of the ECMWF's model under the sub-seasonal to seasonal prediction project of the World Weather Research Program and World Climate Research Program. When the hindcasts are initiated less than two weeks before SSW onset, BCC_CSM and ECMWF show comparable predictive skill in terms of the temporal evolution of the stratospheric circumpolar westerlies and polar temperature up to 30 days after SSW onset. However, with earlier hindcast initialization, the predictive skill of BCC_CSM gradually decreases, and the reproduced maximum circulation anomalies in the hindcasts initiated four weeks before SSW onset replicate only 10% of the circulation anomaly intensities in observations. The earliest successful prediction of the breakdown of the stratospheric polar vortex accompanying SSW onset for BCC_CSM(ECMWF) is the hindcast initiated two(three) weeks earlier. The predictive skills of both models during SSW winters are always higher than that during non-SSW winters, in relation to the successfully captured tropospheric precursors and the associated upward propagation of planetary waves by the model initializations. To narrow the gap in SSW predictive skill between BCC_CSM and ECMWF, ensemble forecasts and error corrections are performed with BCC_CSM. The SSW predictive skill in the ensemble hindcasts and the error corrections are improved compared with the previous control forecasts.Jian RAO Rongcai REN Haishan CHEN Xiangwen LIU Yueyue YU Yang YANG 2019Advances in Atmospheric Sciences2019,36,5:3
13High-energy-density gelled fuels with high stability and shear thinning performance显示文摘Gelled fuels are the very promising propellants for new-generation rocket and ramjet propulsion.Here we report a new type of low-molecular mass organic gellant(Z),and prepared four kinds of stable gelled fuels based on HD-01,HD-03,RP-3 and QC liquid fuels,with the critical gellant concentration less than 1%(mass).The characterizations show that the gellant can form 3D network structure,via hydrogen bonding,π-πstacking and van der Waals forces,to fix fuel molecules during the formation of gelled fuels.So,the gelled fuels show high stability,with the remaining gel mass of 0.25%(mass)Z/HD-01 more than 90%even at high centrifugal speed of 7500 r·min^(-1),but the rheological property test shows that all gelled fuels have obvious shear thinning property,which benefits its storage in gelled state while supply in liquid state.The gelation of liquid fuels by gellant Z can increase the volumetric net heat of combustion(for HD-01,it increases from 39.58 MJ·L^(-1) to 40.76 MJ·L^(-1) with 1%(mass)Z),and liquefied gelled fuels show the comparable ignition delay time with the pristine liquid fuels.So,the gelled fuels made by gellant Z have better stability,shear thinning and combustion performances,which have great potential for the practical application.Yang Liu Hongzhi Zhang Lun Pan Kang Xue Xiangwen Zhang Ji-Jun Zou 2022Chinese Journal of Chemical Engineering2022,35,3:2
14Theoretical design and preparation of high thermal-stable jet fuel显示文摘A high thermal-stable jet fuel design method was developed using composition-properties relations and basic specification properties of jet fuel. Tannery diagrams were provided to visualize relationships among three main components (n-paraffins, iso-paraffins, cycloparaffins, or aromatics) with four major specification properties (density, flash point, freezing point, net heat of combustion) and thermal sta- bility. An optimum chemical composition was established to meet performance requirements: n-paraffins 25%-45%, iso-paraffins 15%-30%, cycloparaffins 30%-50%, and aromatics 5%. The thermal stability test on four fuel samples with and without optimal composition indicated that the thermal stabilities of fuel samples with optimal composition are higher than RP-3 jet fuel, and that the theoretical design method is a reliable method to screen the basic oil for the high thermal-stable jet fuel.LIU GuoZhu QU HaiJie SHEN HuiMing ZHANG XiangWen MI ZhenTao 2008Science China Chemistry2008,51,2:2
15A case of scalp avulsion with prolonged ischemic time:indocyanine green angiography can aid in predicting replant survival显示文摘Background:Microsurgical replantation has become the most favorable treatment option for scalp avulsion.However,the accurate prediction of postoperative replant viability remains challenging.Case presentation:In this article,we showed that(indocyanine green angiography,ICGA)can provide a much more precise prediction of replant necrosis than conventional clinical assessment in a rare case of complete scalp avulsion with prolonged ischemia time.Conclusion:Clinical assessment of replant survival may be misleading in cases of complex tissue injuries and prolonged ischemic stress.This case provides insight into the promising utility of ICGA as an important adjuvant tool to better assess tissue perfusion and viability in scalp avulsion and possibly other types of replantation.Xin Huang Zhichao Wang Caiyue Liu Shuchen Gu Yashan Gao Xiangwen Xu Tao Zan 2019Burns & Trauma2019,7,1:2
16Microstructures and Phase Transition in Omphacite: Constraints on the P-T Path of Shuanghe Eclogite (Dabie Orogen)显示文摘Omphacite microstructures are important to decipher the metamorphic pressuretemperature(P-T)conditions of eclogite during subduction and exhumation processes.Here we present a systematic microstructural investigation of omphacite using transmission electron microscopy(TEM)in an ultrahigh-pressure(UHP)eclogite sample from Shuanghe,Dabie orogen,China.The omphacite can be divided into two phases:(1)Omp-1,exhibits as the main part of omphacite with P2/n space group containing small amount of dislocations and numerous antiphase domains(APDs).(2)Omp-2,shows as banded subgrains with C2/c space group containing large amount of dislocations.These two phases of omphacite have almost the same crystallography orientation and bounded by dislocation walls.Along these dislocation walls,we found some barroisite and albite microcrystals.The barroisite microcrystals contain large amount of dislocations and show a topological relation with host omphacite.While the albite microcrystals contain small amount of dislocations and does not show topological relation with host.These microstructures could give us the following metamorphic information to constrain the P-T path of eclogite:Firstly,this two omphacite space groups should be evolved from the same precursor C2/c omphacite,which had been underwent strongly plastic deformation during the syn-to late-peak metamorphic stage.Secondly,the precursor C2/c omphacite began to be retrograded and altered by small amount of barroisite microcrystals along its dislocation walls under the P-T condition of 2.2–2.6 GPa and 650–700℃ at the early amphibole eclogite stage.Thirdly,large amount of Na and other elements were exsolved from some precursor C2/c omphacite subgrains and crystallized numerous albite microcrystals at their boundaries,which is the necessary for the space group of C2/c surviving under the lower P-T conditions(1.7–1.9 GPa and 630–690 C)during the middle amphibole eclogite stage.Lastly,the rest of precursor C2/c omphacite subgrains were transformed into P2/n polymorph and formed the APDs structures under the P-T condition of^1.5 GPa and 650–680℃ during the late amphibole eclogite stage.Zhanjun Xie Xiangwen Liu Zhenmin Jin Zhuoyue Li 2020Journal of Earth Science2020,31,2:2
17General allometric equations and biomass allocation ofPinus massoniana trees on a regional scale in southern China显示文摘Xian Wenhuag Liu Shaohui Deng Xiangwen 2011Ecological Research2011,26,:1
18Constructing the separation pathway for photo-generated carriers by diatomic sites decorated on MIL-53-NH2(Al)for enhanced photocatalytic performance显示文摘High yield production of phenol from hydroxylation of benzene with low energy consumption is of paramount importance,but still challenging.Herein,a new strategy,consisting of using diatomic synergistic modulation(DSM)to effectively control the separation of photo-generated carriers for an enhanced production of phenol is reported.The atomic level dispersion of Fe and Cr respectively decorated on Al based MIL-53-NH_(2)photocatalyst(Fe1/Cr:MIL-53-NH_(2))is designed,in which Cr single atoms are substituted for Al3+while Fe single atoms are coordinated by N.Notably,the Fe1/Cr:MIL-53-NH_(2)significantly boosts the photooxidation of benzene to phenol under visible light irradiation,which is much higher than those of MIL-53-NH_(2),Cr:MIL-53-NH_(2),Fe1/MIL-53-NH_(2),and Fe nanoparticles/Cr:MIL-53-NH_(2)catalysts.Theoretical and experimental results reveal that the Cr single atoms and Fe single atoms can act as electron acceptor and electron donor,respectively,during photocatalytic reaction,exhibiting a synergistic effect on the separation of the photo-generated carriers and thereby causing great enhancement on the benzene oxidation.This strategy provides new insights for rational design of advanced photocatalysts at the atomic level.Gang Wang Yan Liu Ning Zhao Huimei Chen Wenjie Wu Yueyue Li Xiangwen Liu Ang Li Wenxing Chen Junjie Mao 2022Nano Research2022,15,8:1
19Factors Limiting the Forecast Skill of the Boreal Summer Intraseasonal Oscillation in a Subseasonal-to-Seasonal Model显示文摘In this study,we evaluate the forecast skill of the subseasonal-to-seasonal(S2S)prediction model of the Beijing Climate Center(BCC)for the boreal summer intraseasonal oscillation(BSISO).We also discuss the key factors that inhibit the BSISO forecast skill in this model.Based on the bivariate anomaly correlation coefficient(ACC)of the BSISO index,defined by the first two EOF modes of outgoing longwave radiation and 850-hPa zonal wind anomalies over the Asian monsoon region,we found that the hindcast skill degraded as the lead time increased.The ACC dropped to below 0.5for lead times of 11 days and longer when the predicted BSISO showed weakened strength and insignificant northward propagation.To identify what causes the weakened forecast skill of BSISO at the forecast lead time of 11 days,we diagnosed the main mechanisms responsible for the BSISO northward propagation.The same analysis was also carried out using the observations and the outputs of the four-day forecast lead that successfully predicted the observed northward-propagating BSISO.We found that the lack of northward propagation at the 11-day forecast lead was due to insufficient increases in low-level cyclonic vorticity,moistening and warm temperature anomalies to the north of the convection,which were induced by the interaction between background mean flows and BSISO-related anomalous fields.The BCC S2S model can predict the background monsoon circulations,such as the low-level southerly and the northerly and easterly vertical shears,but has limited capability in forecasting the distributions of circulation and moisture anomalies.Zheng HE Pangchi HSU Xiangwen LIU Tongwen WU Yingxia GAO 2019Advances in Atmospheric Sciences2019,36,1:1
20Enhanced upconversion luminescence in NaYF 4 : Er nanoparticles with multi-wavelength excitation显示文摘Ping Chen Shaoliang Yu Beibei Xu Juechen Wang Xiangwen Sang Xiaofeng Liu Jianrong Qiu 2014Materials Letters2014,,:1
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