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Interannual Variability of Summertime Outgoing Longwave Radiation over the Maritime Continent in Relation to East Asian Summer Monsoon Anomalies

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Journal of Meteorological Research 2017年第4期31卷 665-677页

作者： qi xu Zhaoyong GUAN Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science &Technology Nanjing 210044

The Maritime Continent（MC） is under influences of both the tropical Pacific and the Indian Ocean. Anomalous convective activities over the MC have significant impacts on the East Asian summer monsoon（EASM） and climate in China. In the present study, the variation in convective activity over the MC in boreal summer and its relationship to EASM anomalies are investigated based on regression analysis of NCEP–NCAR reanalysis and CMAP [Climate Prediction Center（CPC） Merged Analysis of Precipitation] data, with a focus on the impacts of ENSO and the Indian Ocean Dipole（IOD）. The most significant interannual variability of convective activity is found over 10°S–10°N, 95°–145°E, which can be roughly defined as the key area of the MC（hereafter, KMC）. Outgoing longwave radiation anomaly（OLRA） exhibits 3- to 7-yr periodicities over the KMC, and around 70% of the OLRA variance can be explained by the ENSO signal. However, distinct convection and precipitation anomalies still exist over this region after the ENSO and IOD signals are removed. Abnormally low precipitation always corresponds to positive OLRA over the KMC when negative diabatic heating anomalies and anomalous cooling of the atmospheric column lead to abnormal descending motion over this region. Correspondingly, abnormal divergence occurs in the lower troposphere while convergence occurs in the upper troposphere, triggering an East Asia–Pacific/Pacific–Japan（EAP/PJ）-like anomalous wave train that propagates northeastward and leads to a significant positive precipitation anomaly from the Yangtze River valley in China to the islands of Japan. This EAP/PJ-like wave pattern becomes even clearer after the removal of the ENSO signal and the combined effects of ENSO and IOD, suggesting that convective anomalies over the KMC have an important impact on EASM anomalies. The above results provide important clues for the prediction of EASM anomalies and associated summer precipitation anomalies in China.

关键词： Maritime Continent convective activity ENSO Indian Ocean Dipole (IOD) East Asian summer monsoon (EASM)

The mechanism of stiffness increase phenomenon of a rubbing disk

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Acta Mechanica Sinica 2010年第3期26卷 441-448页

作者： Shimin Wang Jieqiong xu qi Wang Division of General Mechanics Beihang University 100191 Beijing China

The phase characteristic of a disk rubbing with a ring supported elastically is investigated and used to explain the mechanism of stiffness increase phenomenon. As long as the rubbing is maintained, the averaged phase difference between the disk and the rotating mass on the disk is defi- nitely less than π/2. When the rubbing finishes, the phase difference quickly approaches to 7r. This behavior is inde- pendent of the physics parameters of the rubbing system. The theoretical results are qualitatively verified with experiments.

关键词： Stiffness increase phenomenon Phasecharacteristic Rubbing rotor

Leaching of the residue from the dry off-gas de-dusting and desulfurization process of an iron ore sinter plant

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International Journal of Minerals,Metallurgy and Materials 2015年第2期22卷 116-121页

作者： Christof Lanzerstorfer qi xu Robert Neuhold School of Engineering/Environmental Sciences University of Applied Sciences Upper Austria Siemens VAI Metals Technologies GmbH

The residue from a second-stage dry sinter plant off-gas cleaning process contains both the fine dust from the sinter plant and the sorbent used. Recycling of the material that is usually handled by landfills to the sinter plant feed is not possible because of its chloride con- tent. Leaching of the chlorides allow the recycling of remaining solids. The saline leachate produced contains some heavy metals and must be treated before it is discharged into the sea. In laboratory experiments, leaching tests with the subsequent treatment of the leachate were con- ducted. After the process was optimized, all heavy-metal concentrations were below the permissible values. The optimum treatment condi- tions for heavy-metal precipitation were observed to be the filtration of the suspended solids followed by the dosing of liquid with lime milk （pH 10） and the subsequent precipitation using sodium sulfide.

关键词： heavy metals off-gas cleaning recycling residues leaching sinter plants

Dynamic modeling and simulation of a pressurized system used in flight vehicle

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Chinese Journal of Aeronautics 2018年第6期31卷 1232-1248页

作者： Bing SUN qi xu Yang CHEN School of Astronautics Beihang University

For a typical pressurized system with a novel dual-stage gas pressure reducing regulator,a system model is established with modular models of various typical components. The simulation study on the whole working period shows that the general trends and magnitudes of simulation curves are in agreement with experimental measured curves. As the key component in the pressurized system, the regulator is studied by a series of numerical simulations to reveal the influences of various structure parameters on its stability. Furthermore, the variable ranges which can guarantee the stability of regulator and system are obtained to provide guidance for design. The modeling and analysis approach can be applied to other systems and components.

关键词： Dual-stage gas pressure reducing regulator Dynamic characteristics Finite volume method Numerical simulation Pressurized system Stability

Postzygotic mosaic mutations in autism spectrum disorder and other neuropsychiatric disorders

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Science Bulletin 2017年第24期62卷 1624-1625页

作者： Longze Sha qi xu State Key Laboratory of Medical Molecular Biology & Neuroscience center Institute of Basic Medical Sciences Chinese Academy of Medical Sciences School of Basic Medicine Peking Union Medical College Beijing 100005 China

Autism, or autism spectrum disorder （ASD）, refers to a range of neurodevelopmental disorders characterized by：（1） impaired social interaction, （2） impaired verbal and non-verbal communication, and （3） restricted and repetitive behavior. Although Wpically not diagnosed until the age of 3, symptoms can present during infancy. Early intervention with behavioral therapies has been shown to improve learning, communication, and social skills. This means it is essential to find a method for evaluating characteristics associated with ASD as early as possible .

关键词： Postzygotic mosaic mutations autism spectrum disorder other neuropsychiatric disorders

Thermodynamics and microstructures of Euler–Heisenberg black hole in a cavity

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Communications in Theoretical Physics 2023年第9期75卷 91-103页

作者： qin Yu qi xu Jun Tao Center for Theoretical Physics College of PhysicsSichuan UniversityChengdu610065China

Euler–Heisenberg black holes with quantum electrodynamics(QED) correction are embraced by a cavity in this paper, which serves as a boundary of the black hole spacetime and contributes to the equilibrium of the system. We explore the thermodynamic properties of the black hole, including the phase transitions and phase structures. The small/large black hole phase transition occurs for a negative QED parameter, while the reentrant phase transition can be observed for a small positive QED parameter. Then the thermodynamic geometry is investigated to diagnose microscopic interactions of black hole thermodynamic systems. For the reentrant phase transition, the small black holes are dominated by repulsion for the first-order coexistence curve, while the interaction between the small black hole molecules could be attractive or repulsive for the small/large black hole phase transition.

关键词： black hole thermodynamics phase transition microstructure

Aero-engine fault diagnosis applying new fast support vector algorithm

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航空动力学报 2012年第7期27卷 1604-1612页

作者： xu qi-hua GENG Shuai SHI Jun College of Electronic Engineering Huaihai Institute of Technology Lianyungang Jiangsu 222005 China No. 365 Institute Northwestern Polytechnical University Xi'an 710072 China

A new fast learning algorithm was presented to solve the large-scale support vector machine ( SVM ) training problem of aero-engine fault *** relative boundary vectors ( RBVs ) instead of all the original training samples were used for the training of the binary SVM fault *** pruning strategy decreased the number of final training sample significantly and can keep classification accuracy almost *** , the training time was shortened to 1 / 20compared with basic SVM *** , owing to the reduction of support vector number , the classification time was also *** sample aliasing existed , the aliasing sample points which were not of the same class were eliminated before the relative boundary vectors were *** , the samples near the relative boundary vectors were selected for SVM training in order to prevent the loss of some key sample points resulted from *** can improve classification accuracy effectively.A simulation example to classify 5classes of combination fault of aero-engine gas path components was finished and the total fault classification accuracy reached 96.1%.Simulation results show that this fast learning algorithm is effective , reliable and easy to be implemented for engineering application.

关键词： aero-engine support vector machines fault diagnosis large-scale training set relative boundary vector sample pruning

Synthesis and Reactivity of Trifluoromethylthiophosphonium Salts

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Chinese Journal of Chemistry 2023年第21期41卷 2779-2787页

作者： Wen-qi xu Xiu-Hua xu Feng-Ling qing Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academyof Sciences345 LinglingLuShanghai 200032China

This article described an unprecedented synthesis of trifluoromethylthiophosphonium salts from allyl trifluoromethyl sulfoxide and phosphines in the presence of trimethylsilyl trifluoromethanesulfonate(TMSOTf)through Mislow-Evans-type *** resulting trifluoromethylthiophosphonium salts were firstly isolated and fully *** fluoroalkylphosphonium salts,as exemplified by trifluoromethylthio triphenylphosphonium salt(6a),exhibited unique and versatile reaction with nucleophiles and deoxygenative trifluoromethylthiolation reaction of carboxylic ***,the photoredox catalytic tunable radical hydrotrifluoromethylation and hydrotrifluoromethythiolation of unactivated alkenes with 6a was successfully.

关键词： Phosphonium salts Fluorine Rearrangement Trifluoromethylthiolation Synthetic methods

Synthesis and Properties of CF3(OCF3)CH-Substituted Arenes and Alkenes

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Chinese Journal of Chemistry 2020年第8期38卷 847-854页

作者： Wen-qi xu Xiu-Hua xu Feng-Ling qing Key Laboratory of Organofluorine Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of ScienceChinese Academy of Science345 Lingling LuShanghai 200032China Key Laboratory of Science and Technology of Eco-Textiles Ministry of EducationCollege of ChemistryChemical Engineering and BiotechnologyDonghua University2999 North Renmin LuShanghai 201620China

A silver-mediated oxidative trifluoromethylation of easily accessibleαα-trifluoromethyl alcohols with TMSCF3 was developed to access novel CF3(OCF3)CH-containing *** of CF3(OCF3)CH-substituted arenes afforded synthetically useful CF3O-substituted ***,evaluation of the lipophilicities(log P)indicated that CH(OCF3)CF3 is more lipophilic than the common fluorinated motifs such as CF3,OCF3,and SCF3,thus rendering the CH(OCF3)CF3 motif appealing in drug discovery.

关键词： compounds substituted rendering