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STUDY ON OPTIMUM OF LASER-ShOCkING PARAMETERS FOR IMPROVING FATIGUE LIFE OF AIRCRAFT ALUMINUM　ALLOY

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Acta Metallurgica Sinica(English Letters) 1998年第1期11卷 61-67页

作者： Y.k.Zhang G.R.hua X.h.Lu Jiangsu Univ of Science and Technology Zhenjiang China

The aircraft aluminum 2024-T62 is shock-treated by pulsed laser with the same wavelength and different pulse durations. The laser parameters, arrangements of laser optics and strengthening effects are investigated. The optimal laser-shocking parameters, i.e., a pulse durotion (FWhM) of 30ns, shot spot 7 to 10mm in diameter and pulse energy of 15-20J are obtained under the condition that the Q modulation crystal is kD*P and the laser optical system has three amplification stages. Therefore, the fatigue life of aluminum specimens is increased greatly and the maximum increasement is 23. 7 times.

关键词： Al-Cu-Mg alloy fatigue life laser treatment

A Preliminary Research on a Plasma Spout-Fluid Bed Reactor

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Energy and Power Engineering 2013年第4期5卷 287-290页

作者： L. tang h. huang X. Yang h. hao k. Zhao Department of Civil Engineering Guangzhou University Waihuanxi Road Guangzhou China Department of Environmental Engineering Guangdong University of Technology Waihuanxi Road Guangzhou China

A laboratory-scale plasma spout-fluid bed reactor with a 10 kW DC plasma torch was developed and tested using quartz sand particle and rice hull. The preliminary experimental results including particle recirculation and attrition, bed temperature distribution and stability, as well as biomass gasification system energy balance were presented in this paper. Research results indicated that plasma spout-fluid bed reactor may be a technically feasible reactor for carbonaceous organic material gasification.

关键词： Thermal Plasma Spout-fluid Bed Gasification

A novel method to prepare metal oxide electrode:Spin-coating with thermal decomposition

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Chinese Chemical Letters 2011年第3期22卷 354-357页

作者： hao Xu Wei Yan Cheng Li tang Department of Environmental Science and Technology Xi'an Jiaotong University Xi'an 710049 China

In this work,we propose a new spin-coating method coupling with high thermal decomposition,to prepare the tin-antimony（Sn-Sb） oxide *** character of the spin-coating electrode was compared with the dip-coating electrode through X-ray diffraction（XRD）,scanning electron microscopy（SEM）,accelerated life test,cyclic voltammetry,and electrolytic degradability. The results showed that the spin-coating electrode had a better defined crystal form,a smoother and more compact surface than that of the dip-coating *** time of the spin-coating electrode was determined to be longer than 15 h,and it was less than 2 min for the dip-coating *** characterization analysis showed that the electrolytic degradability of the spin-coating electrode is better than that of the dip-coating electrode.

关键词： Spin-coating Dip-coating Thermal decomposition Electro properties

In-situ interaction of nano-PbS with gelatin

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Science China Chemistry 2013年第11期56卷 1593-1600页

作者： WANG Jun tang Shihua WANG BaiYang LI YouQun Guangxi key Laboratory of Chemistry and Engineering of Forest Products School of Chemistry and chemical Engineering Guangxi University for Nationalities

Water-soluble gelatin-PbS bionanocomposites （BNCs） were synthesized via a facile one-pot chemical reaction method at ph 7.40. The samples were characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD）, UV-vis absorption spectra （UV-vis）, Fourier transform infrared spectra （FT-IR） and circular dichroism （CD）. FT-IR data were used to envis- age the binding of PbS particles with oxygen atoms of carbonyl groups of gelatin molecule. The possible integration mechanism between gelatin and PbS was discussed in detail. The effect of Pb2＋ and PbS on the conformations of gelatin has also been analyzed by means of UV-vis, CD and FT-IR spectra, resulting in less c^-helix content and more open structures （[3-sheet, r-turn, or expanded）. A new formula to calculate the association constant was proposed according to the relationship between the absorbance of gelatin-PbS BNCs and the free concentration of PbS, and apparent association constants k （298/303/308 k： 3.11/2.00/1.60 × 10^6 tool/L） at three different temperatures were calculated based on this formula. Thermodynamic parameters such as AG^θ, △hθ and △S^θ were also determined. The results of the thermodynamic investigations indicated that the reaction was spontaneous （AG^θ 〈 0）, and enthalpy-driven （△h^8 〈 0）.

关键词： gelatin PbS nanoparticle integration mechanism UV-vis spectroscopy thermodynamic parameter

Assessment of major ions and heavy metals in groundwater： a case study from Guangzhou and Zhuhai of the Pearl River Delta, China

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Frontiers of Earth Science 2016年第2期10卷 340-351页

作者： Yintao LU Changyuan tang Jianyao ChEN hong YAO School of Civil Engineering Beijing Jiaotong University Beijing 100044 China Faculty of horticulture Chiba University Chiba 271-8510 Japan School of Geography and planning Sun Yat-sen University Guangzhou 510275 China

Anthropogenic activities in the Pearl River Delta （PRD） have caused a deterioration of groundwater quality over the past twenty years as a result of rapid urbanization and industrial development. In this study, the hydrochemical characteristics, quality, and sources of heavy metals in the groundwater of the PRD were investigated. Twenty-five groundwater samples were collected and analyzed for ph, electrical conductivity （EC）, total dissolved solids （TDS）, δ18O,δ~2h, major ions, and heavy metals. The groundwater was slightly acidic and presented TDS values that ranged from 35.5 to 8,779.3 mg.L-1. The concentrations of the major ions followed the order Cl- 〉 hCO3-〉 Na＋〉 SO24- 〉 NO3 〉 Nh4＋〉 Ca2＋〉 k＋〉 Mg2＋〉 Fe2＋/3＋〉 Al3＋. Ca-Mg- hCO3 and Na-k.hCO3 were the predominant types of facies, and the chemical composition of the groundwater was primarily controlled by chemical weathering of the basement rocks, by mixing of freshwater and seawater and by anthropogenic activities. The heavy metal pollution index （hPI） indicated that 64% of the samples were in the low category, 16% were in the medium category and 20% were in the high category, providing further evidence that this groundwater is unsuitable for drinking. Lead, arsenic, and manganese were mainly sourced from landfill leachate; cadmium from landfill leachate and agricultural wastes; mercury from the discharge of leaehate associated with mining activities and agricultural wastes; and chromium primarily from industrial wastes. According to the irrigation water quality indicators, the groundwater in the PRD can be used for irrigation in most farmland without strong negative impacts. however, approximately9 million people in the Guangdong Province are at risk due to the consumption of untreated water. Therefore, we suggest that treating the groundwater to achieve safer levels is necessary.

关键词： Pearl River Delta groundwater quality,hydrochemical type sodium salts accumulation heavymetal pollution

ThE LEAST SQUARES ESTIMATOR FOR AN ORNSTEIN-UhLENBECk PROCESS DRIVEN BY A hERMITE PROCESS WITh A PERIODIC MEAN

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Acta Mathematica Scientia 2021年第2期41卷 517-534页

作者： Guangjun ShEN Qian YU Zheng tang Department of Mathematics Anhui Normal UniversityWuhu 241000China School of Statistics East China Normal UniversityShanghai 200062China School of Mathematics and Finance Chuzhou UniverstyChuzhou 239012China

We consider the least square estimator for the parameters of Ornstein-Uhlenbeck processes dY_(s)=(∑_(j=1)^(k)μ_(j)φ_(j)(s)-βY_(s))ds+dZ_(s)^(q,h),driven by the hermite process Z_(s)^(q,h)with order q≥1 and a hurst index h∈(1/2,1),where the periodic functionsφ_(j)(s),,j=1,...,κare bounded,and the real numbersμ_(j),,j=1,...,κtogether withβ>0 are unknown *** establish the consistency of a least squares estimation and obtain the asymptotic behavior for the *** also introduce alternative estimators,which can be looked upon as an application of the least squares *** terms of the fractional Ornstein-Uhlenbeck processes with periodic mean,our work can be regarded as its non-Gaussian extension.

关键词： Least squares estimator consistency asymptotic distribution Ornstein-Uhlenbeck processes hermite processes

kinetic study on reactive extraction for chiral separation of phenylsuccinic acid enantiomers

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Science China Chemistry 2010年第11期53卷 2399-2406页

作者： tang keWen MIAO JiaBing ZhOU Tao SONG LiTao Department of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414006China College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China

The kinetics of the extraction of phenylsuccinic acid(PSA) enantiomers by hydroxypropyl-β-cyclodextrin(hP-β-CD) in a modified Lewis cell was studied,in which hP-β-CD dissolved in 0.1 mol L-1 Nah2PO4/h3PO4 buffer solution(ph = 2.5) was selected as the chiral *** enantiomers were extracted from organic phase to aqueous phase in the extraction *** theory of extraction accompanied by a chemical reaction has been used to obtain the intrinsic kinetics of this extraction *** different parameters affecting the extraction rate such as agitation speed,interfacial area,initial concentration of PSA enantiomers in organic phase as well as hP-β-CD concentration in aqueous phase were separately *** experimental results demonstrate that the extraction reactions are *** reactions were found to be first order with respect to PSA and second order with respect to hP-β-CD with forward rate constants of 3.4 × 10-2 m6 mol-2 s-1 for R-PSA and 9.96 × 10?3 m6 mol-2 s-1 for *** data will be useful in the design of extraction processes.

关键词： kinetics reactive extraction chiral separation Lewis cell phenylsuccinic acid enantiomers

A Time Series Short-Term Prediction Method Based on Multi-Granularity Event Matching and Alignment

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Computers, Materials & Continua 2024年第1期78卷 653-676页

作者： haibo Li Yongbo Yu Zhenbo Zhao Xiaokang tang College of Computer Science and Technology Huaqiao UniversityXiamen361021China

Accurate forecasting of time series is crucial across various *** prediction tasks rely on effectively segmenting,matching,and time series data *** instance,regardless of time series with the same granularity,segmenting them into different granularity events can effectively mitigate the impact of varying time scales on prediction ***,these events of varying granularity frequently intersect with each other,which may possess unequal *** minor differences can result in significant errors when matching time series with future ***,directly using matched events but unaligned events as state vectors in machine learning-based prediction models can lead to insufficient prediction ***,this paper proposes a short-term forecasting method for time series based on a multi-granularity event,MGE-SP(multi-granularity event-based short-termprediction).First,amethodological framework for MGE-SP established guides the implementation *** framework consists of three key steps,including multi-granularity event matching based on the LTF(latest time first)strategy,multi-granularity event alignment using a piecewise aggregate approximation based on the compression ratio,and a short-term prediction model based on *** data from a nationwide online car-hailing service in China ensures the method’s *** average RMSE(root mean square error)and MAE(mean absolute error)of the proposed method are 3.204 and 2.360,lower than the respective values of 4.056 and 3.101 obtained using theARIMA(autoregressive integratedmoving average)method,as well as the values of 4.278 and 2.994 obtained using k-means-SVR(support vector regression)*** other experiment is conducted on stock data froma public data *** proposed method achieved an average RMSE and MAE of 0.836 and 0.696,lower than the respective values of 1.019 and 0.844 obtained using the ARIMA method,as well as the values of 1.350 and 1.172 obtained usin

关键词： Time series short-term prediction multi-granularity event alignment event matching

Matthew effect:General design strategy of ultra-fluorogenic nanoprobes with amplified dark–bright states in aggregates

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Aggregate

Aggregate 2024年第2期5卷 482-492页

作者： Shinsuke Segawa Xinwen Ou Tianruo Shen Tomohiro Ryu Yuki Ishii herman h.Y.Sung Ian D.Williams Ryan T.k.kwok ken Onda kiyoshi Miyata Xuewen he Xiaogang Liu Ben Zhong tang Translational and Advanced Bioimaging Laboratory Department of Chemical and Biological EngineeringSchool of EngineeringThe Hong Kong University of Science and TechnologyKowloonHong KongChina Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction and Institute for Advanced StudyThe Hong Kong University of Science and TechnologyKowloonHong KongChina Science Mathematics and Technology ClusterSingapore University of Technology and DesignSingaporeSingapore Department of Chemistry Graduate School of ScienceKyushu UniversityNishi-kuFukuokaJapan The key Lab of health Chemistry and Molecular Diagnosis of Suzhou College of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhouJiangsuChina School of Science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhenGuangdongChina

Fluorescence imaging,a key technique in biological research,frequently utilizes fluorogenic probes for precise imaging in living *** is an effective emission quencher in fluorogenic probe designs,which can be selectively damaged upon bioorthogonal click reactions,leading to considerable emission *** significant efforts to increase the emission enhancement ratio(I_(AC)/I_(BC))of tetrazine-functionalized fluorogenic probes,the influence of molecular aggregation on the emission properties has been largely overlooked in these probe *** this study,we reveal that an ultrahigh I_(AC)/I_(BC)can be realized in the aggregate system when tetrazine is paired with aggregation-induced emission(AIE)*** amplifies its quenching efficiency upon aggregation and drastically reduce background *** click reactions damage tetrazine and trigger significant AIE,leading to considerably enhanced I_(AC)/I_(BC).We further showcase the capability of these ultra-fluorogenic systems in selective imaging of multiple organelles in living *** term this unique fluorogenicity of AIE luminogen-quencher complexes with amplified dark-bright states as“Matthew effect”in aggregate emission,potentially providing a universal approach to attain ultrahigh I_(AC)/I_(BC)in diverse fluorogenic systems.

关键词： aggregation-induced emission bioorthogonal chemistry click chemistry fluorescence imaging tetrazine