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Combustion synthesis,structural,magnetic and dielectric properties of Gd3+-doped lead molybdato-tungstates

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Journal of Advanced Ceramics 2020年第2期9卷 255-268页

作者： T.GRON m.mACIEJKOWICZ E.TOmASZEWIC m.GUZIK m.OBOZ B.saWICKI S.PAWLUS A.NOWOK Z.KUKULA Institute of Physics University of Silesia40-007 KatowicePoland Faculty of Chemical Technology and Engineering Department of Inorganic and Analytical ChemistryWest Pomeranian University of Technology in SzczecinAl.PiastOw 4271-065 SzczecinPoland Faculty of Chemistry University of Wrocławul.F.Joliot-Curie 1450-383 WrocławPoland

Gd^3+-doped lead molybdato–tungstates with the chemical formula of Pb1–3x􀀀xGd2x(moO4)1–3x(WO4)3x(where x=0.0455,0.0839,0.1430,corresponding to 9.53,18.32,33.37 mol%of Gd^3+,respectively,as well as􀀀denotes cationic vacancies)were successfully synthesized via combustion *** XRD and SEm results confirmed the formation of single-phase,tetragonal scheelite-type materials(space group I41/a)with the uniform,spherical and oval grains ranging from 5 to *** grains are strongly agglomerated into big clusters with the size even above *** magnetic measurements as well as the Brillouin fitting procedure showed paramagnetic state with characteristic superparamagnetic-like behaviour and the short-range ferromagnetic *** electrical and broadband dielectric spectroscopy studies revealed insulating properties with the residual electrical n-type conduction of 2×10^–9 S/m and low energy loss(tand»0.01)below 300 *** analysis showed that no dipole relaxation processes in the Gd^3+-doped materials were observed.A fit of dielectric loss spectra of Gd^3+-doped samples by sum of the conductivity and the Havriliak–Negami,Cole–Cole,and Cole–Davidson functions confirmed this effect.

关键词： scheelite Gd^3+-substituted PbmoO4 combustion solid solution magnetic properties dielectric properties

A new one-pot neat synthesis of 1,2,4-triazol-3-ones through 4-(N,N-dimethylamino) pyridine (DmAP) catalyzed cyclocondensation of ethyl carbazate with aryl nitriles

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Chinese Chemical Letters 2008年第6期19卷 685-688页

作者： A.Davoodnia m.Bakavoli m.Soleimany H.Behmadi Department of Chemistry School of SciencesIslamic Azad UniversityMashhad BranchMashhad 91735-413Iran

A new one-pot neat synthesis of some 5-aryl-2,4-dihydro-3H- 1,2,4-triazol-3-ones through cyclocondensation of ethyl carbazate with aryl nitriles catalyzed by DmAP as an efficient and basic nucleophilic catalyst is des... 详细信息

关键词： 1,2,4-Triazol-3-ones One-pot synthesis DmAP Aryl nitriles

An Ecological Evaluation of Vinyl Chloride Exposure and Liver Cancer Incidence and mortality in Texas

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Journal of Clinical and Translational Hepatology 2021年第1期9卷 99-105页

作者： Kevin m.Towle Stacey m.Benson Natalie S.Egnot Gary m.marsh Cardno ChemRisk San FranciscoCAUSA Cardno ChemRisk PittsburghPAUSA

The goal of this analysis was to evaluate the association between county-level ambient vinyl chloride(VC)and county-level liver cancer incidence and mortality rates in *** county-level ambient VC data were obtained from the National Air Toxics ***-adjusted county-level liver cancer incidence rates were abstracted from the Texas Cancer Registry and age-standardized county-level liver cancer mortality rates were obtained from the peer-reviewed *** imputation was utilized to impute incidence rates in counties with suppressed liver cancer incidence *** binomial and Poisson regression models were utilized to evaluate the association between county-level ambient VC and county-level liver cancer incidence and mortality rates,respectively,adjusted for county-level heavy drinking prevalence,hepatitis mortality rates,median income,and race(percent Hispanic).County-level ambient VC was not associated with county-level liver cancer incidence or mortality ***,when compared to the lowest tertile of ambient VC,the middle(relative risk[RR]:1.06,95%confidence interval[CI]:0.95-1.19)and highest(RR:1.03,95%CI:0.90-1.17)tertiles of ambient VC were not associated with liver cancer ***,county-level ambient VC in the middle(RR:0.95,95%CI:0.85-1.05)and highest(RR:0.93,95%CI:0.82-1.05)tertiles were not associated with liver cancer *** analysis suggests that county-level ambient VC is not associated with liver cancer incidence or mortality in *** study provides novel results regarding liver cancer risk from low-level non-occupational exposure to ambient VC.

关键词： Vinyl chloride Liver cancer Epidemiology Incidence

Effect of Cerium Doping on microstructure and Dielectric Properties of BaTiO_3 Ceramics

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Journal of materials Science & Technology 2011年第8期27卷 759-763页

作者： sabina Yasmin Shamima Choudhury m.A. Hakim A.H. Bhuiyan m.J. Rahman Department of Physics University of Dhaka materials Science Division Atomic Energy Centre Department of Physics Bangladesh University of Engineering and Technology

A solid state reaction method was used to synthesize barium titanate （BT） and barium cerium titanate （BCT） ceramics at sintering temperature of 1473 K for 4 h. The effect of cerium （Ce） on the structure, microstructure and dielectric properties of BCT was investigated. The scanning electron microscopy （SEm） investigations revealed that the grain size increases with increasing Ce content. The X-ray diffraction （XI^D） patterns showed mostly the BT phase, where the lattice parameter decreased with the addition of Ce. The temperature dependence of dielectric constant showed decrease in the phase transition temperature with higher Ce content. The dielectric constant decreased slightly with increasing frequency. The direct current （dc） density-voltage characteristics of the ceramics showed ohmic behavior for both the BT and BCT. As the temperature increased, the dc resistivity of the ceramics decreased. The activation energy increased with increasing Ce content.

关键词： Cerium doped Ba1-xCexTiO3 Dielectric constant Current density

Resistance and Reactance of monopole Fields Induced by a Test Charge Drifting Off-Axis in a Cold and Collisional Cylindrical Plasma

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Chinese Physics Letters 2018年第8期35卷 49-53页

作者： m.S.Bawa'aneh A.m.Al-Khateeb Y.-c.Ghim Department of Physics Yarmouk University Department of Nuclear and Quantum Engineering KAIST

We study the interaction of a uniform, cold and collisional plasma with a test charged particle moving off-axis at a constant speed down a cylindrical tube with a resistive thick metallic wall. Upon matching the electromagnetic field components at all interfaces, the induced monopole electromagnetic fields in the plasma are obtained in the frequency domain. An expression for the plasma electric resistance and reactance is derived and analyzed numerically for some representative parameters. Near the plasma resonant frequency, the plasma resistance evolves with frequency like a parallel RLC resonator with peak resistance at the plasma frequency pe, while the plasma reactance can be capacitive or inductive in nature depending on the frequency under consideration.

关键词： In Resistance and Reactance of monopole Fields Induced by a Test Charge Drifting Off-Axis in a Cold and Collisional Cylindrical Plasma

Physical Characterization and elaboration Discussion of a Clay-PEG 6000 Composite with Natural Clay matrix

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Engineering（科研） 2014年第7期6卷 338-354页

作者： Iatimad Akhrif mostapha el Jai Laila mesrar Ahmed elkhalfi Abdelhamid Touache Raouf Jabrane Advanced material and Application Team Ecole Nationale Supérieure d’Arts et Métiers de Meknès Moulay Ismail University Meknes Morocco Geosciences and Environment Laboratory Faculty of Sciences and Techniques Sidi Mohammed Ben Abdellah University Fez Morocco mechanical Engineering Department Faculty of Sciences and Techniques Sidi Mohammed Ben Abdellah University Fez Morocco

In this paper, we compare different nanoclay-PEG composites and the influence of the input parameters especially the percentage of PEG and the clay size. Because of the facility of material elaboration, dried state with grinding, we adopted a complete experiments plan to obtain a maximum of robustness of the responses. For each sample, we made an XRD analysis to see if we obtain the intercalation of the PEG 6000 (Polyethylene Glycol 6000) within the clay sheets. The characterization adopted consists on the measurement of the shrinking of some cylinders we made, the liquidity and plasticity limits according to the Casagrande protocol used in geotechnical clays characterizations. We utilize also the methylen blue protocol to estimate the variation of the specific surface of ionic exchange of the clay sheets according to the PEG 6000 percentage and the clay sizes. SEm microscopy permits to visualize some of the phases detected by the XRD analysis. The TEm microscopy permits also to see the amorphous phases created by the grinding protocol which affects significantly the specific surface and the shrinking of the new materials. For each section, we made some conclusions with interpretation in order to integrate these results in civil engineering, classical/artisanal material construction and geotechnical fields.

关键词： Clay Structure PEG 6000/Clay matrix Composite ICP Analysis Atterberg Limits Specific Surface Shrinking microscopy Characterization

ARImA模型与Gm(1,1)模型对丙型病毒性肝炎发病的预测效果比较研究

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预防医学情报杂志 2024年第10期40卷 1187-1192页

作者：张明玉周钰博吴建军吕珍王引弟 Bilembi m.Olivier 李三三甘肃中医药大学公共卫生学院兰州730100

目的通过ARImA模型与Gm(1,1)模型拟合2013—2022年金昌市的丙型病毒性肝炎发病率数据,探索比较两模型在实际应用中的预测效果。方法从中国疾病预防控制信息系统子系统传染病监测收集2013—2022年甘肃省金昌市居民丙肝发病数据,运用SPSS ... 详细信息

目的通过ARImA模型与Gm(1,1)模型拟合2013—2022年金昌市的丙型病毒性肝炎发病率数据,探索比较两模型在实际应用中的预测效果。方法从中国疾病预防控制信息系统子系统传染病监测收集2013—2022年甘肃省金昌市居民丙肝发病数据,运用SPSS 25.0软件与Excel 2016软件建立ARImA模型与Gm(1,1)模型并进行预测,根据两个模型的均方误差(mean square error,mSE)、均方根误差(root mean square error,RmSE)、平均绝对误差(mean absolute error,mAE)、平均绝对百分比误差(mean absolute percentage error,mAPE)比较评价模型预测效果,检验水准α=0.05。结果拟合模型后显示,最优ARImA模型为ARImA(3,1,1)模型,使用该模型预测2023年丙肝发病率为12.59/10万;而使用Gm(1,1)模型预测2023年丙肝发病率为14.78/10万。ARImA(3,1,1)模型与Gm(1,1)模型预测效果评价指标mSE、RmSE、mAE、mAPE分别为0.672、0.809、0.647、10.913%和16.355、4.044、3.656和14.911%。结论ARImA(3,1,1)模型拟合效果优于Gm(1,1)模型,ARImA模型对金昌市丙肝发病率的预测有较明显的优势,能更精准的处理该类时间序列数据。

关键词： ARImA模型 Gm(1,1)模型丙型病毒性肝炎预测

Evaluation of Soil Quality Indicators in Sugarcane management in sandy Loam Soil

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Pedosphere 2009年第3期19卷 312-322页

作者： S.A.C.saNT'ANNA m.F.FERNANDES W.m.P.m.IVO J.L.S.COSTA Brazilian Agricultural Research Corporation (Embrapa Coastal Tablelands) Av. Beira Mar 3250 Aracaju SE 49025- 040 (Brazil) Departament of Physiology Universidade Federal de Sergipe So Cristóvo SE 49100-000 (Brazil) Brazilian Agricultural Research Corporation (Embrapa Coastal Tablelands) Av. Beira Mar 3250 Aracaju SE 49025-040 (Brazil) Brazilian Agricultural Research Corporation (Embrapa) Brasília DF 70770-901 (Brazil)

An important factor for the sustainability of soils highly susceptible to degradation is the use of monitoring tools that promptly and realistically reflect changes imposed on soil by different cropping systems. To select soil quality indicator variables in sugarcane (saccharum officinarum L.) production areas that fulfill the criteria of sensitivity to management practices and between-season consistency in the management discrimination, ten composite soil samples (0–10 cm) were collected in July 2005 (rainy season) and again in march 2006 (dry season) from areas under cultivation of organic sugarcane (OS), green sugarcane (GS), burned sugarcane (BS) and from an adjacent native forest (NF) area at Usina Triunfo, Boca da mata, Alagoas, Brazil. microbial biomass-C (mBC), total organic C (TOC), soil enzyme activity expressed as the rate of fluorescein diacetate (FDA) hydrolysis, mean weight diameter of water-stable soil aggregates (mWD), and percentage of water-stable macroaggregates (PWsa) were analyzed. Although mBC and TOC were higher in NF than in the cultivated areas, no differences were observed in these C pools between the three sugarcane systems. The response of FDA to the site management was dependent on the sampling time. In the rainy period, the activity followed the order: NF > OS > GS > BS, whereas in the dry season, only NF differed from the other treatments. Irrespective of the sampling time, mWD and PWsa decreased in the order NF > OS = GS > BS. The variables mWD and PWsa are quite sensitive for discriminating between site management histories regardless the sampling season.

关键词： fiuorescein diacetate green-sugarcane organic matter management sugarcane (saccharum oJficinarum L.) sustainable agricultural use

蒙药复方森登-4特征图谱及其中6个指标性成分的含量测定

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北京中医药大学学报 2016年第6期39卷 489-493页

作者：白埔萨础拉董玉内蒙古医科大学药学院内蒙古010059 内蒙古医科大学蒙医药学院

目的建立蒙药复方森登-4特征图谱及同时测定其中没食子酸、京尼平-1-β-D-龙胆二糖苷、栀子苷、（2R,3R）-双氢杨梅素、芦丁、杨梅素6个成分含量的方法。方法采用高效液相色谱‘HPLC’法。蒙药复方森登-4特征图谱色谱系统：用Extend-C1... 详细信息

目的建立蒙药复方森登-4特征图谱及同时测定其中没食子酸、京尼平-1-β-D-龙胆二糖苷、栀子苷、（2R,3R）-双氢杨梅素、芦丁、杨梅素6个成分含量的方法。方法采用高效液相色谱‘HPLC’法。蒙药复方森登-4特征图谱色谱系统：用Extend-C18色谱柱（250 mm×4.6 mm,5μm）,以乙腈（A）-0.6%磷酸水溶液（B）为流动相,流速为1 m L/min,检测波长为254 nm,柱温为25℃,进样量为10μL。蒙药复方森登-4中6个成分含量测定色谱系统：用Extend-C18（250 mm×4.6mm,5μm）色谱柱,以乙腈（A）-0.6%磷酸水溶液（B）为流动相,流速为0.5 m L/min,检测波长为254 nm和292 nm,柱温为27℃,进样量为10μL。结果蒙药复方森登-4特征图谱共检出90多个峰,与标准品HPLC图谱比对,共指认出10个峰,其中6个峰可以含量测定。经后续HPLC含量测定,6个成分的含量均在线性范围内,并与其各自峰面积积分值呈良好的线性关系（均r=0.999 9）;平均回收率在98.29%~103.75%之间,RSD为1.44%~2.97%。结论本法准确、简便、重复性好,可作为蒙药复方森登-4的质量控制方法。

关键词：蒙药复方森登-4 特征图谱没食子酸京尼平-1-β-D-龙胆二糖苷栀子苷 (2R,3R)-双氢杨梅素芦丁杨梅素高效液相色谱法