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Iterative Methods for Solving the Nonlinear Balance Equation with Optimal Truncation

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Advances in Atmospheric Sciences 2021年第5期38卷 755-770页

作者： qin xu Jie CAO NOAA/National Severe Storms Laboratory NormanOklahoma 73069USA Cooperative Institute for Mesoscale Meteorological Studies University of OklahomaNormanOklahoma 73072USA Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China

Two types of existing iterative methods for solving the nonlinear balance equation(NBE)are *** the first type,the NBE is rearranged into a linearized equation for a presumably small correction to the initial guess or the subsequent updated *** the second type,the NBE is rearranged into a quadratic form of the absolute vorticity with the positive root of this quadratic form used in the form of a Poisson equation to solve NBE *** two methods are rederived by expanding the solution asymptotically upon a small Rossby number,and a criterion for optimally truncating the asymptotic expansion is proposed to obtain the super-asymptotic approximation of the *** each rederived method,two iterative procedures are designed using the integral-form Poisson solver versus the over-relaxation scheme to solve the boundary value problem in each *** testing with analytically formulated wavering jet flows on the synoptic,sub-synoptic and meso-αscales,the iterative procedure designed for the first method with the Poisson solver,named M1a,is found to be the most accurate and *** the synoptic wavering jet flow in which the NBE is entirely elliptic,M1a is extremely *** the sub-synoptic wavering jet flow in which the NBE is mostly elliptic,M1a is sufficiently *** the meso-αwavering jet flow in which the NBE is partially hyperbolic so its boundary value problem becomes seriously ill-posed,M1a can effectively reduce the solution error for the cyclonically curved part of the wavering jet flow,but not for the anti-cyclonically curved part.

关键词： nonlinear balance iterative method optimal truncation

The simple synthesis of quinazoline-2,4-dione derivatives using Boc strategy

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Chinese Chemical Letters 2009年第10期20卷 1201-1203页

作者： xu qin Li School of Applied Science University of Science and Technology Beijing Beijing 100083 China

Quinazolinediones are particularly attractivc pharrnacophores because of theix wide range of bioactivities. A convenient synthetic pathway to three-substituted quinazolinc-2,4-dionc derivatives was developed from substituted anthranilamide via carbonylation with Boc anhydride and then cyclization in the presence of the base sodium mcthoxidc. Good to cxceUcnt yields have bccn achieved.

关键词： Quinazolinediones Carbonylation Cyclization Boc strategy

Computing Streamfunction and Velocity Potential in a Limited Domain of Arbitrary *** I:Theory and Integral Formulae

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Advances in Atmospheric Sciences 2011年第6期28卷 1433-1444页

作者： qin xu 高守亭曹洁 NOAA/National Severe Storms Laboratory Norman Oklahoma USA Cooperative Institute for Mesoscale Meteorological Studies University of Oklahoma USA Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 （Received 15 October 2010 revised 9 March 2011）

The non-uniqueness of solution and compatibility between the coupled boundary conditions in computing velocity potential and streamfunction from horizontal velocity in a limited domain of arbitrary shape are revisited theoretically with rigorous mathematic *** integral formulas and their variants are used to formulate solutions for the coupled *** the absence of data holes,the total solution is the sum of two integral *** is the internally induced solution produced purely and uniquely by the domain internal divergence and vorticity,and its two components（velocity potential and streamfunction） can be constructed by applying Green＇s function for Poisson equation in unbounded domain to the divergence and vorticity inside the *** other is the externally induced solution produced purely but non-uniquely by the domain external divergence and vorticity,and the non-uniqueness is caused by the harmonic nature of the solution and the unknown divergence and vorticity distributions outside the *** setting either the velocity potential（or streamfunction） component to zero,the other component of the externally induced solution can be expressed by the imaginary（or real） part of the Cauchy integral constructed using the coupled boundary conditions and solvability conditions that exclude the internally induced *** streamfunction（or velocity potential） for the externally induced solution can also be expressed by the boundary integral of a double-layer（or singlelayer） density *** the presence of data holes,the total solution includes a data-hole-induced solution in addition to the above internally and externally induced solutions.

关键词： integral formulae streamfunction velocity potential domain of arbitrary shape

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Retrieving Soil Water Contents from Soil Temperature Measurements by Using Linear Regression

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Advances in Atmospheric Sciences 2003年第6期20卷 849-858页

作者： qin xu Binbin ZHOU NOAA NationalSevereStormsLaboratoryNormanOklahomaUSA NOAAJNWSflNationalCentersforEnvironmentalPrediction CampSpringsMarylandUSA

A simple linear regression method is developed to retrieve daily averaged soil water content from diurnal variations of soil temperature measured at three or more depths. The method is applied to Oklahoma Mesonet soil temperature data collected at the depths of 5, 10, and 30 cm during 11–20 June 1995. The retrieved bulk soil water contents are compared with direct measurements for one pair of nearly collocated Mesonet and ARM stations and also compared with the retrievals of a previous method at 14 enhanced Oklahoma Mesonet stations. The results show that the current method gives more persistent retrievals than the previous method. The method is also applied to Oklahoma Mesonet soil temperature data collected at the depths of 5, 25, 60, and 75 cm from the Norman site during 20–30 July 1998 and 1–31 July 2000. The retrieved soil water contents are verified by collocated soil water content measurements with rms differences smaller than the soil water observation error (0.05 m3 m−3). The retrievals are found to be moderately sensitive to random errors (±0.1 K) in the soil temperature observations and errors in the soil type specifications.

关键词： retrieval soil water content

Effect of glucose on the soil bacterial diversity and function in the rhizosphere of Cerasus sachalinensis

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Horticultural Plant Journal 2021年第4期7卷 307-317页

作者： Wenjie Zhou xu qin Deguo Lyu Sijun qin College of Horticulture Shenyang Agricultural UniversityShenyang 110866China Small Fruit Institute Eastern Liaoning University/Key Laboratory of Blueberry Breeding and Postharvest HandlingLiaoning ProvinceDandongLiaoning 118003China School of Garden Science and Engineering Shandong Agriculture and Engineering UniversityJinanShandong 250100China

Most cherry orchards in China have low organic carbon content,though carbon is very important for plant *** changes in soil carbon and bacterial diversity were determined after different amounts of 12C-glucose were added to the rhizosphere of Cerasus *** bacteria diversity was measured using high throughput sequencing,and bacteria containing 13C-glucose were identified using DNA-SIP *** results demonstrated that soil microbial biomass carbon(MBC)content and the soil respiratory rate were increased at 3 and 7 days after adding *** soil organic carbon(SOC)content was decreased on the 7th day in the treatment where the added glucose-C was equivalent to the MBC *** content was decreased on the 15th day after adding glucose-C equivalent to five times that of the soil *** to the controls,the relative abundance of taxa at the phylum level displayed no significant change in the treatments with glucose-C added as 10%and equal amount of soil MBC 3–30 days after ***,the relative abundance of Proteobacteria increased significantly in the treatment with the addition of glucose-C equivalent to five times of soil *** main changes were observed in the bacteria in several genera including A4,Flavisolibacter,Aquicella,and Candidatus ***-SIP results indicated that the relative abundance of the Proteobacteria and Pseudomonas was the highest;these were the primary bacteria phylum and genus,respectively,from day 3 to day *** conclusion,the changing pattern demonstrated that with the addition of more glucose,the range of the bacterial communities changed *** and Pseudomonas may be the bacteria promoting priming effect.

关键词： Cerasus sachalinensis Soil respiration Soil organic carbon High throughput sequencing DNA-SIP Priming effect

Lighting up rotaxanes with AIEgens

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Chinese Chemical Letters 2023年第3期34卷 122-133页

作者： Xiao-qin xu xu-qing Wang Wei Wang School of Chemistry and Molecular Engineering East China Normal UniversityShanghai 200062China Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices South China University of TechnologyGuangzhou 510640China

Aiming at the construction of novel rotaxanes with desired luminescent properties for practical applications, recently the rapid development of rotaxanes decorated with aggregation-induced emission(AIE) luminogens(i.e., AIEgens) has been witnessed. The combination of AIEgens and rotaxanes leads to the successful construction of a novel type of luminescent rotaxanes with many attractive features. In particular, the unique controllable dynamic feature of rotaxanes endows the resultant AIEgen-based rotaxanes precisely tunable emissions under external stimuli, leading to the construction of a novel type of smart luminescent materials. In this minireview, the recent progress of AIEgen-based rotaxanes has been summarized, with an emphasis on the design strategy and potential applications.

关键词： Mechanically interlocked molecules Aggregation-induced emission Molecular shuttles F?rster resonance energy transfer Light harvesting Aggregate

Quasiprobability Distribution of Squeezed Thermal Spin States in Ferromagnet

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Communications in Theoretical Physics 2008年第3期49卷 777-782页

作者： xu qin-Feng CHENG Ze Department of Physics Huazhong University of Science and Technology Wuhan 430074 China

We study squeezed properties of magnon squeezed thermal spin states by using the distribution of Q function in the ferromagnet. It is found that the distribution of Q function strongly depends on the temperature T and coupling parameter γ. Below the transition temperature Tc, the distribution Q function in the squeezed thermal spin state presents a richer structure than in the normal state. Non-classical effects have been observed. In the transition from the normal to the squeezed thermal spin state, the phase symmetry of the magnon system is spontaneously broken.

关键词： squeezed thermal spin state ferromagnon quasiprobability distribution function

Application of Xenopus laevis in ecotoxicology （Ⅰ）--Introduction and quality control of laboratory animal

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Chinese Science Bulletin 2006年第11期51卷 1273-1280页

作者： qin Zhanfen xu Xiaobai State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-environmental Sciences Chinese Academy ofSciences Beijing 100085 China

The aim of the series of papers is to discuss the application of Xenopus laevis, as model animal in biology, in ecotoxicology. X. laevis as model animal is wildly used in biological study and has pro- vided a lot of relating data because of many advan- tages, such as living in water and being easily main- tained, laying eggs in the whole year, and externally fertilizing and developing. Embryos and larvae of X. laevis like other amphibians are directly exposed in the aquatic environment and sensitive to pollutants. In addition, sex differentiation and sex organ devel- opment of X. laevis are sensitive to sex hormones and endocrine disruptors with sex hormone activities, which enable X. laevis to be used in studies on sex hormone disruption and reproductive toxicity of en- docrine disruptors. Metamorphic development of X. laevis is very sensitive to thyroid hormones and thy- roid disruptors, which enables X. laevis to be used for evaluating thyroid disruptors. Also, X. laevis ecotoxi- cology can be linked with amphibian population de- clines and malformed frog occurrence, being one of the hotspots in ecology. Thus, more and more labo- ratories have introduced X. laevis to ecotoxicological study. The quality of laboratory animals correlates with scientificity and reliability of results from animal experiments. It is especially important for toxicology. Quality control of X. laevis involving several factors such as water and food is discussed in this paper.

关键词：有爪蟾蜍生态毒理学实验动物质量控制

Covalent organic frameworks functionalized carbon fiber paper for the capture and detection of hydroxyl radical in the atmosphere

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Chinese Chemical Letters 2020年第9期31卷 2495-2498页

作者： Zhiling Huang qin xu Xiaoya Hu School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China Guangling College Yangzhou UniversityYangzhou 225002China

Developing a fast,sensitive and convenient method for the detection of hydroxyl radicals(·OH) in the atmosphere could help us know the precursor levels of atmospheric species and control air *** this work,the carbon fiber paper(CFP) functionalizing with a kind of covalent organic frameworks(COFs),formed from 1,3,5-triformylphloroglucinol(Tp) and benzidine(BD)(COF(TpBD)),was firstly used a new platform for ·OH trapping and *** COF(TpBD) modified CFP was acted as a filter to impregnate salicylic acid(SA) and a detector to detect 2,5-dihydroxybenzoic acid(2,5-DHBA) which was produced from the reaction between the impregnated SA and ’OH in the *** method provided a linearity for 2,5-DHBA from 5.0×10^-14 mol/L 1.0×10^-9 mol/L with a detection limit of 6.9×10^-15 mol/L,which is corresponding to the amount of ·OH from 3.0×10^7 to 6.0×10^11 molecules/cm3 with the detection limit of 4.1×10^6 molecules/*** COF(TpBD)-CFP platform has been successfully applied for the detection of ·OH concentration under different conditions of Yangzhou when the sampling time was shortened to 30 *** work has provided a new method for atmospheric·OH detection with excellent sensitivity,simplicity,and high speed.

关键词： Covalent organic frameworks Hydroxyl radical Electrochemical Detection