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固相萃取-超高效液相色谱-串联质谱法测定蜂蜜中39种植物源性毒素

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食品科学 2025年第2期46卷 231-239页

作者：刘川陈燕秋林浩汪璐瑶石培育刘蓉王义吴文林毛锐肖全伟宋娟戴琴成都市食品检验研究院四川成都611130 国家市场监督管理总局重点实验室(新食品原料监测与评价) 四川成都611130 国家市场监督管理总局重点实验室(营养与健康化学计量及应用) 北京100029 辐照保藏四川省重点实验室四川成都611130

为有效评估蜂蜜中可能残留多种植物源性毒素的食品安全风险,建立和验证固相萃取-超高效液相色谱-串联质谱测定蜂蜜中39种植物源性毒素的检测方法。试样经0.1%甲酸水提取,HLB小柱净化,多反应监测模式检测,基质匹配外标法定量。本方法中3... 详细信息

为有效评估蜂蜜中可能残留多种植物源性毒素的食品安全风险,建立和验证固相萃取-超高效液相色谱-串联质谱测定蜂蜜中39种植物源性毒素的检测方法。试样经0.1%甲酸水提取,HLB小柱净化,多反应监测模式检测,基质匹配外标法定量。本方法中39种植物源性毒素在各自浓度范围内线性关系良好,平均回收率介于78.7%~112.8%,相对标准偏差介于1.6%~15.2%(n=6)。该方法具有操作简单、检测通量大、灵敏度高等特点,能够满足蜂蜜中该类毒素监测的应用需求。在实际36批次样品的检测过程中,部分样品分别检出了不同含量的吡咯里西啶生物碱和闹羊花毒素III,证明蜂蜜中确具有残留该类植物毒素的风险。

关键词：固相萃取超高效液相色谱-串联质谱蜂蜜植物源性毒素

Dynamic Compression Behavior of Ultra-high Performance Cement-based Composite with Hybrid Steel Fiber Reinforcements

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Journal of wuhan University of Technology(Materials Science) 2020年第5期35卷 900-907页

作者： rong Zhidan wang Yali wu Shenping School of Materials Science and Engineering Southeast UniversityNanjing 211189China Jiangsu Key Laboratory of Construction Materials Southeast UniversityNanjing 21189China

Ultra-high performance cement-based composites (UHPCC) is promising in construction of concrete structures that suffer impact and explosive *** this study,a reference UHPCC mixture with no fiber reinforcement and four mixtures with a single type of fiber reinforcement or hybrid fiber reinforcements of straight smooth and end hook type of steel fibers were *** Hopkinson pressure bar (SHPB) was performed to investigate the dynamic compression behavior of UHPCC and X-CT test and 3D reconstruction technology were used to indicate the failure process of UHPCC under impact *** show that UHPCC with 1% straight smooth fiber and 2% end hook fiber reinforcements demonstrated the best static and dynamic mechanical *** the hybrid steel fiber reinforcements are added in the concrete,it may need more impact energy to break the matrix and to pull out the fiber reinforcements,thus,the mixture with hybrid steel fiber reinforcements demonstrates excellent dynamic compressive performance.

关键词： ultra-high performance cement-based composite dynamic compression behavior hybrid fiber reinforcements split Hopkinson pressure bar

Interplay of Crosslinking Structures and Segmental Dynamics in Solid-Liquid Elastomers

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Chinese Journal of Polymer Science 2022年第10期40卷 1297-1306,I0012页

作者： Hao wang Wan-Su Peng Qi wu Yan Zhao Shi-Tai wang Yi Yang Jin-rong wu Xiao-Liang wang rong-Chun Zhang South China Advanced Institute for Soft Matter Science and Technology(AISMST) School of Emergent Soft MatterSouth China University of TechnologyGuangzhou 510640China Key Laboratory of High-Performance Polymer Materials and Technology of Ministry of Education Department of Polymer Science and EngineeringSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210093China State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu 610065China Suzhou Niumag Analytical Instrument Corporation Chengdu 610065China Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices South China University of TechnologyGuangzhou 510640China

There have been significant interests in recent years for incorporating dynamic bonds into polymer materials for achieving multiple functionalities,such as self-healing,recycling,stimuli-responsiveness,and so ***,the impact of dynamic bonds on the polymer dynamics is actually less *** this study,we investigate a self-healing solid-liquid elastomer(SLE),which is a dual-crosslinked network made by coupling a permanently crosslinked polydimethylsiloxane(PDMS)network with polyborosiloxane(PBS)via abundant dynamic boron/oxygen dative *** double-quantum(DQ)NMR reveals that the crosslinking degree is reduced while the structural heterogeneity of network is enhanced with increasing PBS content,i.e.,increasing the content of dynamic boron/oxygen dative *** experiments clearly reveal two chain relaxation modes in the SLE samples with a characteristic relaxation time of around 2.1 s and 11.8 s,corresponding to the relaxation of coupled PBS and PDMS chains,*** master curves obtained from variable-temperature frequency-dependent rheological experiments also reveal enhanced heterogeneity of chain relaxation with increasing PBS ***,the impact of boron/oxygen dative bonds on the Rouse dynamics is further revealed by fast-field-cycling(FFC)NMR experiments,where the spinlattice relaxation rate(R_(1))of all SLE samples follows the same power law of R_(1)(ω)∝ω^(-0.33).Nevertheless,the incorporation of PBS did slightly increase the energy barrier of Rouse *** study well demonstrates a combined use of rheology and solid-state NMR spectroscopy can provide piercing insights into the interplay of crosslinking structures and dynamics of polymer materials.

关键词： Fast-field-cycling NMR Multiple-quantum NMR Rheology Dynamics Dynamic bonds

Tribological analysis of the surface layer coated by sintered serpentine-reinforced composites

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Acta Metallurgica Sinica(English Letters) 2018年第6期31卷 615-622页

作者： Xiao wang Jun-Wei wu Lu-Hai Zhou Xi-Cheng Wei wu-rong wang School of Materials Science and Engineering Shanghai University

In this work,the serpentine powders were sintered to make the serpentine-reinforced Al-matrix composites,and the microstructures of which were characterized by differential scanning calorimetry,thermal gravimetric analyzer,and X-ray *** electron microscopy equipped with energy dispersive *** show that the sintered serpentine powders were deeply absorbed on the worn surface and embedded in the furrows and scratches of the matrix,forming a self-repairing surface layer which reduces the friction *** surface layer coated by serpentine was compact,dense,and uniform with the friction time prolonged,compensating the worn loss and increasing the matrix mass.

关键词： Serpentine Friction Wear Surface layer

Smoothness of Certain Functions in Two Kinds of Risk Models with a Barrier Dividend Strategy

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Acta Mathematicae Applicatae Sinica 2010年第4期26卷 661-668页

作者： Wei wang Jing-min He rong wu School of Mathematical Sciences and LPMC Nankai UniversityTianjin 300071China College of Science Tianjin University of TechnologyTianjin 300191China

In this paper,we study the smoothness of certain functions in two kinds of risk models with a barrier dividend *** using technique from the piecewise deterministic Markov processes theory,we prove that the function is continuously differentiable in the first risk *** the weak infinitesimal generator method of Markov processes,we prove that the function is twice continuously differentiable in the second risk ***-differential equations satisfied by them are derived.

关键词： Piecewise deterministic Markov process weak infinitesimal generator barrier strategy

Simulation of Urban Land Expansion Under Ecological Constraints in Harbin-Changchun Urban Agglomeration,China

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Chinese Geographical Science 2022年第3期32卷 438-455页

作者： GUO rong wu Tong wu Xiaochen LUIGI Stendardo wang Yueqin Key Laboratory of Cold Region Urban and Rural Human Settlement Environment Science and Technology Ministry of Industry and Information Technology/School of ArchitectureHarbin Institute of TechnologyHarbin 150006China Department of Civil Architectural and Environmental EngineeringPadova UniversityPadova 35131Italy School of Economics and Management Northeast Forestry UniversityHarbin 150040China

Under the demand of urban expansion and the constraints of China’s’National Main Functional Area Planning’policy,urban agglomerations are facing with a huge contradiction between land utilization and ecological protection,especially for HarbinChangchun urban agglomeration who owns a large number of land used for the protection of agricultural production and ecological *** alleviate this contradiction and provide insight into future land use patterns under different ecological constraints’scenarios,we introduced the patch-based land use simulation(PLUS)model and simulated urban expansion of the Harbin-Changchun urban *** verifying the accuracy of the simulation result in 2018,we predicted future urban expansion under the constraints of three different ecological scenarios in *** morphological spatial pattern analysis(MSPA)method and minimum cumulative resistance(MCR)model were also introduced to identify different levels of ecological security pattern(ESP)as ecological *** predicted result of the optimal protection(OP)scenario showed less proportion of water and forest than those of natural expansion(NE)and basic protection(BP)scenarios in *** conclusions are that the PLUS model can improve the simulation accuracy at urban agglomeration scale compared with other cellular automata(CA)models,and the future urban expansion under OP scenario has the least threat to the ecosystem,while the expansion under the natural expansion(NE)scenario poses the greatest threat to the *** with the MSPA and MCR methods,PLUS model can also be used in other spatial simulations of urban agglomerations under ecological constraints.

关键词： urban land expansion patch-based land use simulation(PLUS)model Harbin-Changchun urban agglomeration scenario simulation ecological constraints China

Synthesis of Tin Oxide Through Thermal Decomposition of Sn_2(NH_4)_2(C_2O_4)_3 and Its Gas Sensing Property

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Chemical Research in Chinese Universities 2005年第6期21卷 641-645页

作者： SHI Juan wu Shi-hua wang Shu-rong School of Materials Science and Chemical Engineering Tianjin Polytechnic University Tianjin 300160 P. R. China Department of Chemistry Nankai University Tianjin 300071 P. R. China

Nanocrystalline tin oxide samples were prepared by using Sn2 （NH4 ）2 （C2O4）3 as the precursor. The thermal decompositions were respectively conducted at 250,450 and 650 ℃. TG-DTA, XRD, TEM, FTIR were used to characterize the samples. The indirect heating sensors by using these materials as sensitive bodies were fabricated on an alumina tube with Au electrodes and platinum wires. Sensing properties of these sensors were investigated. It was found that the tin oxide sample obtained by thermal decomposition at 450 ℃ has a higher sensitivity to C2H5OH and a higher selectivity to hexane and ammonia than those obtained via the conventional precipitate method and the working temperatures needed were greatly decreased.

关键词： Tin dioxide Thermal decomposition Gas sensing property Selectivity

Steady thermocapillary-buoyant convection in a shallow annular pool. Part 1:Single layer fluid

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Acta Mechanica Sinica 2011年第5期27卷 360-370页

作者： You-rong Li Shuang-Cheng wang Chuan-Mei wu College of Power Engineering Chongqing University 400044 Chongqing China Key Laboratory of Low-grade Energy Utilization Technologies and Systems Ministry of Education400044 Chongqing China

This paper examines the steady thermocapillarybuoyant convection in a shallow annular pool subjected to a radial temperature gradient. A matched asymptotic theory is used to obtain the asymptotic solutions of the flow and thermal fields in the case of small aspect ratios,which is defined as the ratio of the layer thickness to the gap width. The flow domain is divided into the core region away from the cylinder walls and two end regions near each cylinder wall. Asymptotic solutions are obtained in the core region by solving the core and end flows separately and then joining them through matched asymptotic expansions. For the system of silicon melt,the asymptotic solutions are compared with the results of numerical simulations. It is found that the two kinds of solutions have a good agreement in the core region for a small aspect ratio. With the increase of aspect ratio,the applicability of the present asymptotic solutions decreases gradually.

关键词： Thermocapillary-buoyant flow. Annular shallow pool. Single layer fluid. Asymptotic solution

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A universal pipeline for mobile mRNA detection and insights into heterografting advantages under chilling stress

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Horticulture Research 2020年第1期7卷 2575-2584页

作者： Ying wang Lingping wang Nailin Xing Xiaohua wu Xinyi wu Baogen wang Zhongfu Lu Pei Xu Ye Tao guojing Li Yuhong wang Institute of Vegetables Zhejiang Academy of Agricultural SciencesHangzhou 310021China Institute of Vegetables Ningbo Academy of Agricultural SciencesNingbo 315040China State Key Laboratory for Quality and Safety of Agroproducts Zhejiang Academy of Agricultural SciencesHangzhou 310021China Biozeron Biotechnology Co. Ltd.Shanghai 201800China Present address:College of Life Sciences China Jiliang UniversityHangzhou 310018China

Heterografting has long been used to enhance the chilling tolerance of temperature-sensitive crops,including watermelon,whose mechanism is known to involve bidirectional long-distance mRNA *** several studies reporting on mobile mRNA(mb-mRNA)profiles in plants,accurate identification of mb-mRNAs is challenging owing to an array of technical ***,we developed a bioinformatical pipeline that took most of the known technical concerns into consideration and is considered to be a universal tool for mb-mRNA detection in *** applying this pipeline to a commercial watermelon–bottle gourd heterografting system,we detected 130 and 1144 mb-mRNAs upwardly and 167 and 1051 mb-mRNAs downwardly transmitted under normal and chilling-stress conditions,*** real-time PCR indicated a high accuracy rate(88.2%)of mb-mRNA prediction with our *** further revealed that the mobility of mRNAs was not associated with their *** annotation and classification implied that scions may convey the stress signal to the rootstock,subsequently triggering energy metabolism reprogramming and abscisic acid-mediated stress responses by upward movement of effective mRNAs,ultimately leading to enhanced chilling *** study provides a universal tool for mb-mRNA detection in plant heterografting systems and novel insights into heterografting advantages under chilling stress.

关键词： metabolism grafting stress