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烟草科技 2018年第A1期51卷 38-46页

作者： YANG Fei TANG Gangling FAN Ziyan WANG Ying LIU Shanshan DENG Huimin BIAN Zhaoyang LI Zhonghao Chinn national Tobacco quality supervision and test center No.2 Fengyang Street Zhengzhou 450001 China

The purpose of this study was to develop and validate a novel and sensitive method for simultaneous enantiomeric analysis of quizalofop-ethyl in tobacco using ultra-performance converge nee chromatography with tandem mass spectrometry(UPC-MS/MS).Sample preparation prior to UPC^2-MS/MS analysis followed a QuEChERS(quick,easy,cheap,effective,rugged and safe)*** UPC^2-MS/MS method used an Acquity UPC2 Trefoil CEL2 column with a mobile phase of CO2 and *** injection volume was 2 μL and run-time was 6 min with the mobile phase running at 2.0 mL/min flow *** temperature,auto back pressure regulator pressure(ABPR),and modifier solvent were optimized for separation *** the optimal conditio ns,the recoveries for all the ena ntiomers were 81.3%-94.8% with relative standard deviations(RSD)less than 5.0% at 0.1,1.0 and 2.0 mg/kg levels,*** coefficients of determination(R^2≥0.993 7)were achieved for all the studied enantiomers in the tobacco over the concentration range of 10-250 ng/*** limits of detection(LODs)varied from 0.02 mg/kg to 0.04 mg/kg,and the limits of quantification(LOQs)were ≤ 0.13 mg/*** results confirm that the proposed method is green,convenient and reliable for the enantioselective determination of the enantiomers of quizalofop-ethyl in tobacco.

关键词： Quizalofop-ethyl Stereoselective separation Herbicide Tandem mass spectrometry Ultraperformance convergence chromatography

The structure of XLPE and the distribution of space charge

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Science China(Physics,Mechanics & Astronomy) 2003年第2期46卷 185-190页

作者：李吉晓张冶文郑飞虎吴长顺夏钟福 Pohl Institute of Solid State Physics Tongji UniversityShanghai 200092China China national center for quality supervision and test of Electric Wire and Cable Shanghai 200093China

The formation and accumulation of space charge under charge treatment are investigated using PWP method. The interaction between space charge and the structure of XLPE is measured using infrared spectroscopy (IR) meth... 详细信息

关键词： space charge, cross-linked polyethylene, IR.

Determination of total alkaloid in tobacco by a safe and improved method based on KSCN

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烟草科技 2018年第A1期51卷 57-61页

作者： HE Shengbao ZHANG Wei LUO Anna WANG Yingyuan FENG Xiaomin LIU Nan China national Tobacco quality supervision and test center No.2 Fengyang Street Zhengzhou 450001 China

In this paper,an analytical method based on a chemical reaction between KSCN and sodium dichloroisocyanurate-dihydrate in a buffer system was applied to quantify the total alkaloid in *** proposed method replaced the No.35 Recommended Method of CORESTA(CRM 35)with the advantage that this method is safer compared to the CRM35 which uses KCN,a highly toxic *** addition,compared to the current national standard method YC/T 468一2013,the buffer solution preparation was optimized to improve the detection *** validation results indicated that the new method met the test requirements,and the results were consistent with the ones obtained from the CORESTA CRM 35 and the YC/T 468一2013 methods.

关键词： Total Alkaloid Tobacco Safer Method KSCN KCN

Crystallization Behavior and Mechanical Properties of Poly(vinylidene fluoride)/multi-walled Carbon Nanotube Nanocomposites

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Chemical Research in Chinese Universities 2010年第3期26卷 491-495页

作者： XU Yue ZHENG Wei-tao YU Wen-xue HUA Li-gui ZHANG Yu-jie ZHAO Zhu-di Key Laboratory of automobile Materials of Ministry of Edueation Test Science Experiment Center Jilin University Changchun 130012 P. R. China Jilin Province Product quality supervision test Institute Changchun 130022 P R. China

Poly（vinylidene fluoride）（PVDF）/multi-walled carbon nanotube（MWCNT） nanocomposites were prepared by means of ultrasonic dispersion method. X-ray diffraction（XRD） results indicate that incorporating MWCNTs into PVDF caused the formation of β phase. A thermal annealing at 130 ℃ confirmed that the β phase was stable in the nanocomposites. Differential scanning calorimetry（DSC） results indicate that the melting temperature slightly increased while the heat of fusion markedly decreased with increasing MWCNT content. The tensile strength and modulus of PVDF were improved by loading the MWCNTs. The scanning electron microscopy（SEM） observations showed that MWCNTs were uniformly dispersed in the PVDF matrix and an interfacial adhesion between MWCNT and PVDF was achieved, which was responsible for the enhancement in the tensile strength and modulus of PVDE.

关键词： Multi-walled carbon nanotube Poly(vinylidene fluoride) Composite Crystalline structure Mechanical property

Exploration of High-Harmonic Generation from the CS2 Molecule by the Lewenstein Method in Two-Color Circularly Polarized Laser Field

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Chinese Physics Letters 2017年第1期34卷 65-68页

作者：张宏丹郭静史岩杜慧刘海风黄旭日刘学深景俊 Institute of Atomic and Molecular Physics Jilin UniversityChangehun 130012 Institute of Theoretical Chemistry Jilin UniversityChangchun 130012 national center of quality supervision and Inspection of automobile Spare Parts Changchun 130012

The high harmonic generation (HHG) from the CS2 molecule in intense laser fields is investigated using the extended Lewenstein method. The initial state is the highest-occupied molecular orbital of the CS2 molecule, which can be well described by Gaussian wave packet using GAMESS-UK package. Compared with the case of the elliptical laser, the HHG can be extended in two-color circularly polarized laser field. The time-frequency analysis and classical electron trajectory as well as the ionization yield curve are also presented to further explain the underlying mechanism. After adding a static electric field on the z-direction, the single quantum path control is realized and the supercontinuum spectra are obtained. Moreover, an isolated 110 as pulse can be obtained by superposing the harmonics from 130th to 180th order.

关键词： Exploration of High-Harmonic Generation from the CS2 Molecule by the Lewenstein Method in Two-Color Circularly Polarized Laser Field CS

Microstructure and Hydrogen Absorption/Desorption Behavior of Mg23-xLaxNi10 Alloy

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Journal of Wuhan University of Technology(Materials Science) 2018年第2期33卷 476-484页

作者：董小平杨丽颖 PANG Yanrong WANG Tao WEN Lijuan College of quality and Technical supervision Hebei University Baoding 071002 China Research center of New Energy automobile Hebei University Baoding 071002 China

Induction melting was used as a routine method to synthesize Mg_（23）Ni_（10）, Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloys, and followed by a detailed microstructural characterization which included X-ray diffraction（XRD）, scanning electron microscopy（SEM） with energy dispersive spectrometer（EDS）, high resolution transmission electron microscope（HRTEM） and hydrogen absorption/desorption measurements. XRD analysis results showed that Mg_2Ni and Mg phases were detected in the XRD pattern of the Mg_（23）Ni_（10） alloy, however, the La addition results in conversion from Mg to LaMg_3 and La_2Mg_（17） phases and appearance of crystal defects included dislocations, twin grain boundary and vacancy in the Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloy textures. The total maximum hydrogen absorption capacity was 4.45 wt% for the Mg_（23）Ni_（10） alloy, however, the Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloys with vacancy, dislocations and twin grain boundary, absorbed 3.66 wt% and 3.60 wt%, respectively, indicating that the La addition led to decreasing of the maximum hydrogen absorption capacity. Besides, hydrogen absorption/desorption of 90% of saturated state expended for about 456 and 990 s for pristine Mg_（23）Ni_（10） alloy, by contrast, the time decreased owing to improvement of hydrogen absorption and desorption kinetics in the alloy with La element, with which the uptake time for hydrogen content to 90% of saturated state was 150 and 78 s, and 90% hydrogen can be released in 930 and 804 s for Mg_（22）LaNi_（10） and Mg_（21）La_2Ni_（10） alloys in the experimental condition.

关键词： Mg-based alloy microstructure hydrogen absorption/desorption behavior

Formation and migration of space charge packet in low density polyethylene

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Science China(Technological Sciences) 2005年第3期48卷 354-360页

作者： ZHENG Feihu 1 , ZHANG Yewen 1 , GONG Bin 1 , ZHU Jianwei 1 & WU Changshun 2 1. Pohl Institute of Solid State Physics, Tongji University, Shanghai 200092, China 2. China national center for quality supervision and test of Electric Ware and Cable, Shanghai 200093, China 1. Pohl Institute of Solid State Physics Tongji University 200092 Shanghai China 2. China national center for quality supervision and test of Electric Ware and Cable 200093 Shanghai China

Pressure wave propagation (PWP) method was utilized to observe the space charges packet-like behavior in sheet samples of low-density polyethylene (LDPE) under the relative low electric field. The experimental results show that space charge packets are always generated at the anode and move across the sample to the cathode regardless of the polarity of DC voltage. This paper discusses the migration of space charge packets at 30–40°C, the possible charge resource of space charge packets carriers and trap level of the space charge.

关键词： solid dielectric,low-density polyethylene,space charge packet,trap.

Research on hydraulic-powered roof supports test problems

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Journal of Coal Science & Engineering(China) 2011年第2期17卷 201-206页

作者： SUN Hong-bo JIANG Jin-qiu MA Qiang test Branch China Coal Research Institute Beijing 100013 China China national Coal Mine Support Equipment quality supervision test center Beijing 100013 China

The load-bearing characters of hydraulic-powered roof support with dual telescopic legs were analyzed. With a specific type hydraulic-powered roof support with dual telescopic legs for research object, the inside load test problems in factories was analyzed, and the correct test methods were given, which can enhance the test efficiency and make the factories away from the error design of hydraulic-powered roof supports and legs.

关键词： dual telescopic legs hydraulic-powered roof support load

Simultaneous identification and quantification of tetrodotoxin in fresh pufferfish and pufferfish-based products using immunoaffinity columns and liquid chromatography/quadrupole-linear ion trap mass spectrometry

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Chinese Journal of Oceanology and Limnology 2017年第4期35卷 883-893页

作者：郭萌萌吴海燕江涛谭志军赵春霞郑关超李兆新翟毓秀 Key Laboratory of testing and Evaluation for Aquatic Product Safety and quality Ministry of AgricultureYellow Sea Fisheries Research InstituteChinese Academy of Fishery Sciences national center for quality supervision and test of Aquatic Products Key Laboratory of Food Safety Risk Assessment Ministry of HealthChina National Center for Food Safety Risk Assessment

In this study, we established a comprehensive method for simultaneous identification and quantification of tetrodotoxin （TTX） in fresh pufferfish tissues and pufferfish-based products using liquid chromatography/quadrupole-linear ion trap mass spectrometry （LC-QqLIT-MS）. TTX was extracted by 1% acetic acid-methanol, and most of the lipids were then removed by freezing lipid precipitation, followed by purification and concentration using immunoaffinity columns （IACs）. Matrix effects were substantially reduced due to the high specificity of the IACs, and thus, background interference was avoided. Quantitation analysis was therefore performed using an external calibration curve with standards prepared in mobile phase. The method was evaluated by fortifying samples at 1, 10, and 100 ng/g, respectively, and the recoveries ranged from 75.8%--107%, with a relative standard deviation of less than 15%. The TTX calibration curves were linear over the range of 1-1 000 ~tg/L, with a detection limit of 0.3 ng/g and a quantification limit of 1 ng/g. Using this method, samples can be further analyzed using an information- dependent acquisition （IDA） experiment, in the positive mode, from a single liquid chromatography-tandem mass spectrometry injection, which can provide an extra level of confirmation by matching the full product ion spectra acquired for a standard sample with those from an enhanced product ion （EPI） library. The scheduled multiple reaction monitoring method enabled TTX to be screened for, and TTX was positively identified using the IDA and EPI spectra. This method was successfully applied to analyze a total of 206 samples of fresh pufferfish tissues and pufferfish-based products. The results from this study show that the proposed method can be used to quantify and identify TTX in a single run with excellent sensitivity and reproducibility, and is suitable for the analysis of complex matrix pufferfish samples.

关键词： tetrodotoxin fresh pufferfish pufferfish-based product immunoaffinity column liquidchromatography/quadrupole-linear ion trap mass spectrometry

A rapid protein sample preparation method based on organic-aqueous microwave irradiation technique

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Science China Chemistry 2015年第3期58卷 526-531页

作者： Shuaibin Wu Hongfei Zhang Kaiguang Yang Junfeng Ma Zhen Liang Lihua Zhang Yukui Zhang Key Laboratory of Separation Sciences for Analytical Chemistry National Chromatographic R&A CenterDalian Institute of Chemical Physics Chinese Academy of Sciences China national Tobacco quality supervision and test center College of Chemistry and Chemical Engineering Hubei Normal University Department of Biological Chemistry the Johns Hopkins University School of Medicine

Fast and efficient sample preparation methods are a prerequisite for protein identification in bottom-up proteomics. Here, an innovative microwave irradiation sample preparation method was developed based on an optimized organic-aqueous solvent system for protein identification. Specifically, protein solutions containing high-concentration acetonitrile were subjected to 5 min microwave irradiation. After cooling down, trypsin was added and the digestion was performed with 30 s microwave irradiation, and the resulting peptides were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS). A shortened processing time of only 5.5 min is needed with this method(more than 12 h is necessary in the traditional overnight protein sample preparation). Moreover, due to the absence of urea and other chaotropic reagents, the digests can be readily identified by MALDI-TOF MS. When an assessment of this method was performed by digesting a model protein BSA, 69% ± 3% sequence coverage corresponding to 47 ± 3 peptides was obtained, which shows better protein identification than that from the standard overnight protein sample preparation method(51% ± 2% sequence coverage and 23 ± 1 peptides). Another model protein α-casein was used for the analysis of protein phosphorylation with the newly developed method that yielded 4 phosphopeptides with 8 phosphorylation sites, whereas 3 phosphopeptides with 2 phosphorylation sites were obtained from the traditional overnight approach. Moreover, the organic-aqueous microwave irradiation method provides effective digestion for proteins down to fmol.

关键词： MALDI-TOF MS microwave organic-aqueous solvent protein identification digestion