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Direct and rapid detection of serum amino acid and monoamine neurotransmitters to assist the diagnosis of panic disorder

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Science China Chemistry 2025年第1期68卷 377-384页

作者： Shiwen Liu xuerui Wan Meng Zhao Jiaqi Wang Weilan Wu Linlin You Yonggui Yuan qian xu Rong Gao Key Laboratory of Environmental Medicine Engineering Ministry of Education School of Public Health Southeast University Key Laboratory of Modern Toxicology of Ministry of Education Department of Hygienic Analysis and Detection School of Public HealthNanjing Medical University Department of Psychosomatics and Psychiatry Zhongda Hospital School of Medicine Southeast University

The measurement of amino acid and monoamine neurotransmitters（NTs） in serum plays a central role in the identification and monitoring of clinical panic disorder（PD）. However, the strong polarity and chemical heterogeneity of NTs make direct extraction and rapid detection extremely challenging. Herein, we developed a strategy that integrated solid phase extraction based on magnetic Fe3O4coated with polydopamine（Fe3O4@PDA） and direct analysis of mass spectrometry in real time（DART-MS） for quantification of 10 NTs. We systematically investigated the optimal conditions of this strategy to achieve good accuracy and precision. Compared with existing magnetic solid phase extraction methods for NTs detection in biological samples, this strategy could adsorb more targets while having similar adsorption efficiencies, and the total process time was reduced by an average of 69.42%. We rapidly determined the metabolic abnormality of 6 types of NTs in the serum of PD patients and demonstrated their diagnostic accuracy. In addition, an outstanding feature of PD in which tryptophan was more metabolized by the KYN pathway and the 5-hydroxytryptamine pathway was inhibited could be elucidated by this strategy. Our results highlighted the potential ability of Fe3O4@PDA coupled with DART-MS to assist in the clinical diagnosis of PD.

关键词： neurotransmitters panic disorder magnetic solid phase extraction direct analysis of mass spectrometry in real time

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Detection of Phthalate Esters in Environmental Water Samples -Comparison of Nylon6 Nanofibers Mat-based Solid Phase Extraction and Other Conventional Extraction Methods

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Chinese Journal of Chemistry 2011年第3期29卷 567-574页

作者： xu, qian Ministry of Education Key Laboratory of Environmental Medicine and Engineering Southeast University Nanjing Jiangsu 210009 China State Key Laboratory of Bioelectronics Southeast University Nanjing Jiangsu 210096 China Suzhou Key Laboratory of Environment and Biosafety Suzhou Jiangsu 215123 China

In this article, a new method for simultaneous determination of six phthalate esters was developed by a combination of electrospun nylon6 nanofibers mat-based solid phase extraction with high performance liquid chromatography-ultraviolet detector （HPLC-UV）. The six phthalate esters were dimethyl phthalate （DMP）, diethyl phthalate （DEP）, butyl benzyl phthalate （BBP）, di-n-butyl phthalate （DBP）, di-（2-ethylhexyl） phthalate （DEHP） and dioctyl phthalate （DOP）. Under optimized conditions, all target analytes in 50 mL environmental water samples could be completely extracted by 2.5 mg nylon6 nanofibers mat and eluted by 100 μL solvent. Compared with C18 cartridges solid phase extraction, C 18 disks solid phase extraction and national standard method （China）, nylon6 nanofibers mat-based solid phase extraction was advantageous in aspects of simple and fast operation, low consumption of extraction materials and organic solvents. The four methods were applied to analysis of environment water samples. All the results indicated that the determination values of target compounds with the proposed method were consistent with C18 cartridges and C18 disks solid phase extraction method, and the new method was better than the national standard method in aspects of recovery, LOD and precision. Therefore, nylon6 nanofibers mat has great potential as a novel material for solid phase extraction.

关键词： Nylon6 nanofibers mat C18 cartridges C18 disks national standard method phthalate esters highperformance liquid chromatography-ultraviolet detector

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Revolutionizing photothermal CO_(2)hydrogenation with ceria-based catalysts

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Nano Research 2025年第1期18卷 30-49页

作者： Zhaorui Zhang Xiao Han Junhong Zhang Yunyun Dong Jinsheng Zhao qian xu ingqiang Zhang School of Chemistry and Chemical Engineering Liaocheng UniversityLiaocheng 252059China Institute for Catalysis Hokkaido UniversityN-21W-10Sapporo 001-0021Japan National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China

In the context of achieving carbon neutrality,CO_(2)catalytic conversion technologies are effective in reducing atmospheric CO_(2)concentrations while simultaneously producing renewable *** approach is seen as a viable method for constructing a new carbon cycle,thereby effectively addressing the issue of global *** CO_(2)conversion has recently emerged as a promising research focus due to its high energy utilization efficiency,superior CO_(2)conversion,excellent product selectivity,mild operating conditions,low energy consumption and minimal operating *** oxide(CeO_(2))has been widely used in photothermal catalysis due to its unique chemical properties,particularly when used as a support material with supported metals,creating distinctive interfacial sites for catalytic *** an emerging star support in photothermal CO_(2)conversion,its contributions are equally significant and should not be ***,to our knowledge,there has been no comprehensive review of CeO_(2)applications in catalytic hydrogenation of CO_(2).In this paper,we summarize and discuss CeO_(2)-based materials for photothermal CO_(2)conversion to value-added *** research particularly focuses on the synthesis methods of CeO_(2)-supported catalysts,the history of CeO_(2)in photothermal catalysis,types of photothermal catalytic reactors,unique characterization methods for the photothermal catalysts and the photothermal CO_(2)hydrogenation reactions by CeO_(2)-based *** related to further challenges and future directions for photothermal CO_(2)hydrogenation are also provided.

关键词： CO_(2)neutrality hydrogenation photothermal catalysis ceria C1 chemistry

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Poisson Equation on Some Complete Noncompact Manifolds

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Acta Mathematica Sinica,English Series 2007年第4期23卷 623-638页

作者： xu qian FAN Department of Mathematics Ji'nan University Guangzhou 510632 P. R. China

We study the Poisson equation on some complete noncompact manifolds with asymptotically nonnegative curvature. We will also study the limiting behavior of the nonhomogeneous heat equation on some complete noncompact m... 详细信息

关键词： Poisson equation heat equation Green's function

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The spatial distribution characteristics of shallow fissures of a landslide in the Wenchuan earthquake area

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Journal of Mountain Science 2016年第9期13卷 1544-1557页

作者： xu Xing-qian Key Laboratory of Mountain Hazards and Earth Surface Process Chinese Academy of SciencesChengdu 610041China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Shallow fissures, being the main infiltration paths of fluid on the surface of a slope, played an important role in the whole process of a landslide. However, the spatial distribution characteristics of fissures in the slope are difficult to be determined. In this study, we attempted to characterize the variation pattern of slope fissures along depth in the Wenchuan earthquake area in Sichuan Province by combining engineering geological investigation, geomorphologic analysis and geophysical investigation. The geophysical methods that were used in this study include Multichannel Analysis of Surface Wave(MASW), Ground Penetrating Radar(GPR) and Electrical Resistivity Tomography(ERT). The results suggested that geophysical parameters(shear wave velocity, electromagnetic signals attenuation and resistivity) could provide valuable information for the spatial network of shallow fissures. Through the verification by engineering geological survey and geophysical sensitivity analysis, this work highlighted that MASW was the most appropriate technique to delineate the propagation of shallow fissures in a gravel soil slope.

关键词： Shallow fissures Landslide Wenchuanearthquake Geophysical prospecting

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The Stability of Nontrivial Positive Steady States for the SKT Model with Large Cross Diffusion

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Acta Mathematicae Applicatae Sinica 2020年第3期36卷 657-669页

作者： Qing LI qian xu College of Arts and Sciences Shanghai Maritime UniversityShanghai 201306China Institute of Fundamental and Interdisciplinary Sciences Beijing Union UniversityBeijing 100101China

This paper is concerned with the existence and stability of steady state solutions for the SKT biological competition model with *** applying the detailed spectral analysis and in virtue of the bifurcating direction to the limiting system as the cross diffusion rate tends to infinity,it is proved the stability/instability of the nontrivial positive steady states with some special bifurcating ***,the existence and stability/instability of the corresponding nontrivial positive steady states for the original cross-diffusion system are proved by applying perturbation argument.

关键词： spectral analysis stability cross-diffusion system

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The Existence and Stability of Steady States for a Prey-predator System with Cross Difusion of Quasilinear Fractional Type

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Acta Mathematicae Applicatae Sinica 2014年第1期30卷 257-270页

作者： qian xu Yue GUO Department of Basic Courses Being Union University College of Mathematical Sciences Capital Normal University Beijing No.19 Middle School

This paper is concerned with the existence and stability of steady states for a prey-predator system with cross diffusion of quasilineax fractional type. We obtain a sufficient condition for the existence of positive steady state solutions by applying bifurcation theory and a detailed priori estimate. In virtue of the principle of exchange of stability, we prove the stability of local bifurcating solutions near the bifurcation point.

关键词： global bifurcation stability

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Synthesis of Methyl Glycolate by Hydrogenation of Dimethyl Oxalate over Cu-Ag/SiO_2 Catalyst

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Journal of Natural Gas Chemistry 2007年第1期16卷 78-80页

作者： Baowei Wang qian xu Hua Song Genhui xu School of Chemical Engineering and Technology Key Lab for Green Chemical Technology Tianjin University Tianjin 300072 China

Methyl glycolate is a good solvent and can be used as feedstock for the synthesis of some important organic chemicals. Catalytic hydrogenation of dimethyl oxalate （DMO） over copper-silver catalyst supported on silica was studied. The Cu-Ag/SiO2 catalyst supported on silica sol was prepared by homogeneous deposition-precipitation of the mixture of aqueous euprammonia complex and silica sol. The proper active temperature of Cu-Ag/SiO2 catalyst for hydrogenation of DMO was 523-623 K. The most preferable reaction conditions for methyl glycolate （MG） were optimized： temperature at 468-478 K, 40-60 mesh catalyst diameter, H2/DMO ratio 40, and 1.0 h^-1 of LHSV.

关键词： dimethyl oxalate methyl glycolate ethylene glycol hydrogenation Cu-Ag/SiO2 catalyst

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Design and analysis of firewall-penetrated scheme based on trusted host

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The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 39-44页

作者： ZHANG Deng-yin WANG qian-qian xu Jian Computer Institute Nanjing University of Posts and Telecommunications Nanjing 210003 China

On the basis of various firewall-penetrated technologies, a novel firewall-penetrated technology based on trusted host, which can realize the communication between penetrating host and protected host, is proposed in this paper. Meanwhile, the firewall-penetrated evaluating model and its formalized statement is also proposed by quantizing penetrated level, penetrated quality, and penetrated hiding. Finally, the fuewall-penetrated technology based on trusted host is analyzed under the fuewall-penetrated evaluating model, and the experimental results show that this technology has obvious penetrating effect and high penetrating quality.

关键词： firewall-penetrated trusted host (TH) penetrated host penetrated evaluating model

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Spatial Distribution Characteristics and Influencing Factors of Agricultural Specialized Villages in Guangdong Province,China

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Chinese Geographical Science 2022年第6期32卷 1013-1034页

作者： YANG Ren ZHANG Xin xu qian School of Geography and Planning Sun Yat-sen UniversityGuangzhou 510006China Land Research Center Sun Yat-sen UniversityGuangzhou 510275China School of Public Administration Guangdong University of Finance&EconomicsGuangzhou 510320China

China is vigorously implementing a rural revitalization strategy with the prosperity of rural industries as the primary *** characteristic economy of’One Village One Product’(OVOP)is particularly significant in promoting rural revitalization and increasing farmers’*** identifying the spatial distribution characteristics and influencing factors of agricultural specialized villages(ASVs)under OVOP provides a preliminary research basis for constructing the theoretical framework of specialization and clustering of rural industrial *** study takes Guangdong Province,China as an example,using kernel density estimation,Ripley’s K function,geometric fractals,principal component regression and other methods to identify the spatial distribution characteristics and influencing factors of *** was found that the ASVs in Guangdong Province are dominated by the planting industry,with an uneven number in space and a multi patch ***,ASVs are mainly distributed in the Chaoshan Plain in the eastern Guangdong,the northern mountainous area of Guangzhou,and the eastern part of Maoming *** spatial distribution mode obeys the aggregation distribution pattern at the scale of province,region and municipality(prefecture-level city).In addition,the formation and development of ASVs are affected by multiple internal and external *** influence of basic factors such as natural environmental conditions is gradually weakening,while the influence of social and economic factors such as market demand is gradually *** study can enrich the research results of ASVs and provide guidance and reference for the long-term and high-quality development of rural industry revitalization.

关键词： One Village One Product(OVOP) agricultural specialization spatial distribution rural industry revitalization

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