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Fidelity of the APHRODITE Dataset in Representing Extreme Precipitation over Central Asia

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Advances in Atmospheric Sciences 2020年第12期37卷 1405-1416页

作者： Sheng LAI zuowei xie Cholaw BUEH Yuanfa GONG College of Atmospheric Science Chengdu University of Information TechnologyChengdu 610225China International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Using rain-gauge-observation daily precipitation data from the Global Historical Climatology Network(V3.25)and the Chinese Surface Daily Climate Dataset(V3.0),this study investigates the fidelity of the AHPRODITE dataset in representing extreme precipitation,in terms of the extreme precipitation threshold value,occurrence number,probability of detection,and extremal dependence index during the cool(October to April)and warm(May to September)seasons in Central Asia during 1961–*** distribution of extreme precipitation is characterized by large extreme precipitation threshold values and high occurrence numbers over the mountainous *** APHRODITE dataset is highly correlated with the gauge-observation precipitation data and can reproduce the spatial distributions of the extreme precipitation threshold value and total occurrence ***,APHRODITE generally underestimates the extreme precipitation threshold values,while it overestimates the total numbers of extreme precipitation events,particularly over the mountainous *** biases can be attributed to the overestimation of light rainfall and the underestimation of heavy rainfall induced by the rainfall distribution–based *** deficits are more evident for the warm season than the cool season,and thus the biases are more pronounced in the warm season than in the cool *** probability of detection and extremal dependence index reveal that APHRODITE has a good capability of detecting extreme precipitation,particularly in the cool season.

关键词： APHRODITE extreme precipitation Central Asia Xinjiang fidelity

One-Pot Process to Carborano-Coumarin via Catalytic Cascade Dehydrogenative Cross-Coupling

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Chinese Journal of Chemistry 2020年第4期38卷 383-388页

作者： Yik Ki Au Hairong Lyu Yangjian Quan zuowei xie Deportment of Chemistry and State Key Laboratory of Synthetic Chemistry The Chinese University of Hong KongShatinN.T.Hong KongChina

Summary of main observation and conclusion Ir-catalyzed cascade dehydrogenative CH/BH and BH/OH cross-coupling of carboranyl carboxylic acid with readily available benzolc acid has been achieved,leading to the facile synthesis of previously unavailable carborano-coumarin in a simple one-pot *** cage B-H,one aryl C--H and one 0-H bonds are activated to construct eficiently new B-C and B-0 *** cascade cyclization can stop at the first B-H/C-H cross-coupling step by tuning the reaction conditions,resulting in a series of a-carboranyl benzoic acid and aryl carborane *** experiments indicate that B-H/C-H dehydrocoupling proceeds preferentially over B-H/O-H dehydrocoupling,and both directing groups and oxidants are crucial for this *** iridium(V)intermediate is proposed to be involved in the catalytic cycle.

关键词： reaction. process. coupling

A Novel Identification of the Polar/Eurasia Pattern and Its Weather Impact in May

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Journal of Meteorological Research 2019年第5期33卷 810-825页

作者： Ni GAO Cholaw BUEH zuowei xie Yuanfa GONG College of Atmosphere Science Chengdu University of Information TechnologyChengdu 610225 International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029

The Polar/Eurasia(POL) pattern was previously identified based on the empirical orthogonal function method and monthly mean data, in which the positive and negative phases are anti-symmetric in spatial distribution. This paper identifies the positive(POL+) and negative(POL-) phases of the POL pattern through applying a novel approach, i.e.,self-organizing maps, to daily 500-h Pa geopotential height fields in May over 1948–2017. The POL+, POL1-, and POL2-patterns defined by this method represent actual physical modes. The POL+ pattern features a wave train from the northeastern Atlantic/northern Europe via the subarctic regions of Eurasia to Lake Baikal. The POL1-pattern is characterized by a planetary-scale dipole pattern with a positive anomaly band over subarctic Eurasia and a negative anomaly band from central Asia to the Sea of Okhotsk. The anomaly centers of the POL2-pattern are basically antisymmetrical to those of the POL+ pattern. The POL+ pattern increases the blocking frequency over the northeastern Atlantic/northern Europe and northeastern Asia, where high-frequency transient eddies are highly recurrent in the north. Accordingly, precipitation increases apparently in the subarctic Asian continent and western Siberia, and decreases around Europe and Lake Baikal. A mimic wave train is also observed in the surface air temperature anomaly field. During the POL1-period, the blocking frequency is abnormally high over Eurasia, whereas high-frequency transient eddies are apparently suppressed over northern Eurasia. Correspondingly, significant precipitation deficits are observed in northern Eurasia. The POL1-pattern also causes a remarkable temperature increase in the subarctic seas of Eurasia and a considerable temperature drop in the midlatitude Asian continent. As the POL2-pattern prevails, the blocking frequency decreases over the North Atlantic/Europe but strengthens over the Asian continent. The POL2-pattern also causes wavelike anomalies of precipitation a

关键词： Polar/Eurasia(POL) pattern self-organizing maps blocking transient eddy

Wave-Breaking Features of Blocking over Central Siberia and Its Impacts on the Precipitation Trend over Southeastern Lake Baikal

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Advances in Atmospheric Sciences 2020年第1期37卷 75-89页

作者： Dorina CHYI zuowei xie Ning SHI Pinwen GUO Huijun WANG Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing 210044China International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Nansen-Zhu International Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Precipitation over southeastern Lake Baikal features a significant decreasing trend in July and August over 1979–2018 and is closely related to blocking occurrence over central Siberia(45°–70°N,75°–115°E).This study investigates the formation and maintenance of anticyclonic and cyclonic wave-breaking(AWB and CWB)blocking events and their climate impacts on precipitation in the southeastern Lake Baikal *** AWB and CWB blocking events are characterized by a cold trough deepening from the sub-Arctic region and a ridge amplifying toward its north over central Siberia,as well as an evident Rossby wave train over midlatitude *** AWB blocking events,the ridge and trough pair tilts clockwise and the wave train exhibits a zonal *** contrast,ridge and trough pair associated with CWB blocking events leans anticlockwise with larger-scale,meridional,and more anisotropic ***,the incoming Rossby wave energy associated with CWB blocking events is more evident than for AWB blocking ***,CWB blocking events are more *** blocking events produce more extensive and persistent precipitation over the southeastern Lake Baikal area than CWB blocking events,in which moderate above-normal rainfall is seen in the decaying periods of blockings.A significant decreasing trend is found in terms of AWB blocking occurrence over central Siberia,which may contribute to the downward trend of precipitation over southeastern Lake Baikal.

关键词： Rossby wave-breaking blocking Siberia precipitation Lake Baikal

Synthesis of carborane-fused cyclobutenes and cyclobutanes

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Science China Chemistry 2014年第8期57卷 1157-1163页

作者： YUAN YingGen REN ShiKuo QIU ZaoZao WANG ShaoWu xie zuowei Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Laboratory of Functional Molecular Solids Ministry of EducationAnhui Laboratory of Molecule-Based MaterialsInstitute of Organic Chemistry School of Chemistry and Materials Science Anhui Normal Universit Department of Chemistry The Chinese University of Hong Kong Shatin Shatin

Transmetalation of carborane-fused zirconacycles to Cu（II） induces the C-C coupling reaction to form four-membered rings. This serves as a new efficient and general methodology for the generation of a series of carborane-fused cyclobutenes and cyclobutanes. A reaction mechanism involving transmetalation to Cu（II） and reductive elimination is proposed.

关键词： carborane cyclobutene cyclobutane zirconacycle copper

Copper Catalyzed Asymmetric [4＋2] Annulations of D-A Cyclobutanes with Aldehydes

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Chinese Journal of Chemistry 2018年第1期36卷 47-50页

作者： Jiang-Lin Hu Li Zhou Lijia Wang zuowei xie Yong Tang The State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis Shanghai Institute of Organic Chemistry Chinese Academy of Sciences 345 Lingling RoadShanghai 200032 China Collaborative Innovation Center of Chemical Science and Engineering Tianjin China

Copper catalyzed enantioselective [4＋2] annulations of D-A cyclobutanes and aldehydes have been developed. In the presence of a side arm modified chiral bisoxazoline （SaBOX） ligand, the [4＋2] annulations proceeded smoothly with a broad substrate scope. 22 examples were studied, leading to the corresponding products with various functional groups in 41%-99% yields with 〉99/1 dr and 90%-96% ee. The resulting product with two ester groups was mono-reduced, giving the corresponding product in excellent diastereoselectivity without loss of the enantiopurity.

关键词： [4+2] annulation cyclobutane enantioselective copper bisoxazoline

The development of a powerful Mongolian cyclone on 14-15 March 2021:Eddy energy analysis

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Atmospheric and Oceanic Science Letters 2022年第6期15卷 42-49页

作者： Cholaw Bueh Anran Zhuge zuowei xie Mei Yong Gomboluudev Purevjav International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina College of Geographical Science Inner Mongolia Normal University HohhotChina Inner Mongolia Key Laboratory of Remote Sensing&Geography Information System Inner Mongolia Normal UniversityHohhotChina Information and Research Institute of Meteorology Hydrology and EnvironmentNational Agency for Meteorology and Environmental MonitoringJuulchinhy gudamj-5UlaanbaatarMongolia

Intense and extensive dust,caused by a strong Mongolian cyclone,hit Mongolia and northern China on 14-15 March *** this study,the development process of this cyclone is analysed from the perspective of highfrequency eddy *** the low-frequency circulation field of early March of 2021,an amplified polar vortex intruding towards central Asia and a ridge straddling eastern and northeastern Asia worked in concert to comprise a strong baroclinic zone from central Asia to Lake *** these favourable conditions,on 13 March,a migratory trough triggered the Mongolian cyclone by crossing over the Sayan *** downwards transfer of kinetic energy from the eddy at 850 hPa played a key role in the intensification and mature stage of the *** mechanism was primarily completed by the cold air sinking behind the cold *** frontal cyclone wave mechanism became crucial once the cyclone started to rapidly *** authors emphasize that the anomalously large growth of high-frequency available potential energy,which characterized this super strong cyclone,was obtained by extracting energy first from the time-mean available potential energy and then from the low-frequency available potential *** interannual temperature anomaly pattern of"north cold south warm"facilitated the additional time-mean available potential energy,and the temperature anomaly pattern of"northwest cold southeast warm"conditioned the extra low-frequency available potential *** analysis results suggest that the interaction between high-and low-frequency waves was also important in the development of the intense cyclone.

关键词： Mongolian cyclone Dust weather Kinetic energy Available potential energy Frontal cyclone wave

Highly regio- and enantioselective synthesis of chiral polysubstituted 2H-pyrroles

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Science China Chemistry 2014年第8期57卷 1058-1058页

作者： xie zuowei The Chinese University of Hong Kong

As one of the most important five-member heterocyclic aromatic rings, pyrrole is widely distributed in numerous natural products and pharmaceutical agents. Asymmetric dearomatization of pyrroles is very attractive in organic synthesis given the fact that highly functionalized chira pyrrolines and pyrrolidines could be easily accessed from the readily available pyrroles. However, the reported asymmetric dearomatization reactions of pyrroles are limited to transition-metal-catalyzed [4＋3] cycloaddition and hydrogenation reactions.

关键词：对映选择性合成区域选择性吡咯手性过渡金属催化加氢反应环加成反应五元杂环

Reaction of [η~5:σ-Me_2C(C_5H_4)(C_2B_(10)H_(10))]Ru(NCCH_3)_2 with internal alkynes:Synthesis and structural characterization of ruthenium-cyclobutadiene and ruthenacyclopentatriene complexes

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Science China Chemistry 2010年第10期53卷 2123-2128页

作者： QIU ZaoZao, SUN Yi & xie zuowei Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China Department of Chemistry The Chinese University of Hong Kong Hong Kong China

Reaction of [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(NCCH3)2 (1) with R1C≡CR1(R1 = Et, Ph) in toluene at 80 °C yielded organoruthenium cyclobutadiene complexes [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(-4-C4R14) in >80% yield. Treatment of 1 with diynes R2C≡C(CH2)3C≡CR2 (R2 = Me, Et) in toluene at room temperature yielded ruthenacyclopentatrienes [η5:σ-Me2C (C5H4)(C2B10H10)]Ru[=C2(R2)2C2(CH2)3] in >85% yield. These new complexes were fully characterized by various spectroscopic techniques, elemental analyses and single-crystal X-ray diffraction studies. The possible reaction mechanism was proposed.

关键词： alkyne carborane diyne ruthenacyclopentatriene ruthenium ruthenium-cyclobutadiene