简介:Wemeasurethecurrent–voltage(I–V)characteristicsforthesinglecrystalofTl0.4K0.41Fe1.71Se2withthesuperconductingtransitiontemperature(TC)around30.5K,undera10Tmagneticfieldappliedperpendicularandparalleltotheabplane.WefindthattheshapesoftheI–Visothermsareverydifferentfromthedescriptionbythevortex-glass(VG)model.CombiningtheoreticalcalculationsandanalysisoftheρH⊥ab–TandρHab–Tdata,wegiveanexplicitdiscussionoverthesuitabilityoftheVGmodelfortheA0.8Fe2Se2superconductors,andpointoutthepossibilityofthematerialactingasaconvenientplatformforre-examinationandfurtherstudyofthecomplexvortexbehaviorsinthelayeredsuperconductors.
简介:摘要:为了加快建设安全高效、绿色智能的干散货港口码头,于是建立一套集现场设备、控制系统、管理系统于一体的管控一体化系统是非常有必要的, 本文基于唐山港曹妃甸港区煤码头三期工程着重介绍了FactoryTalk平台中SE10.0在管控一体化系统中的应用,并对多种不同的管控数据交互接口进行了多次的测试与研究分析,通过对比不同接口的实现方式,最终选择了更适合本工程的多种交互方式相结合的管控一体化接口系统,以更好的实现本工程的建设要求。
简介:背景:激素性股骨头坏死发病率高,预后差,发病机制尚不明确。氧化应激治疗与股骨头坏死的发生发展密切相关。纳米Se具有良好的抗氧化作用。目的:观察多孔纳米复合材料Se@SiO2通过抗氧化应激抑制活性氧对软骨细胞的保护作用,进一步探索抗氧化应激效应在治疗激素性股骨头坏死中的机制。方法:(1)体外实验:提取、培养并鉴定大鼠软骨细胞,采用多孔纳米复合材料Se@SiO2进行干预培养抑制活性氧产生;(2)体内动物实验:将36只大鼠随机分为3组,激素诱导组和实验组均采用腹腔注射脂多糖联合肌注甲强龙诱导股骨头坏死,实验组在诱导后第7天给予腹腔注射多孔Se@SiO2干预治疗,对照组为空白对照。诱导坏死后第8周取双侧股骨头行MicroCT扫描分析,苏木精-伊红染色观察。结果与结论:(1)活性氧检测和TUNEL实验显示:Se@SiO2干预后大鼠软骨细胞中活性氧水平明显降低(P〈0.05);(2)MicroCT扫描分析:与对照组相比,激素诱导组及实验组骨密度、骨体积、骨表面积/骨体积、骨小梁数、骨小梁分离度、骨小梁厚度差异均有显著性意义(P〈0.05);(3)苏木精-伊红染色显示,对照组股骨头表面光滑,骨细胞、软骨细胞、骨小梁正常,空骨陷窝和脂肪细胞少见;激素诱导组骨小梁断裂、脂肪细胞肥大融合、出现大量空骨陷窝,有明显骨坏死表现;实验组较激素诱导组股骨头坏死明显好转;(4)结果表明多孔纳米复合材料Se@SiO2具有良好的抗氧化应激能力,能够抑制活性氧的产生并治疗早期激素性股骨头坏死。
简介:利用Protel99SE进行印刷电路板设计时,在进行网络表加载时经常会出现节点标记出错的问题,对此笔者通过实例,提出了解决的办法。
简介:Broadband(1.6–18THz)terahertztime-domainspectroscopy(THz-TDS)andtime-resolvedterahertzspectroscopy(TRTS)wereperformedona54μmthickchalcogenideglass(As30Se30Te40)samplewithatwo-colorlaser-inducedairplasmaTHzsystemintransmissionandreflectionmodes,respectively.Twoabsorptionbandsat2–3and5–8THzwereobserved.TRTSrevealsanultrafastrelaxationprocessofthephotoinducedcarrierresponse,welldescribedbyarateequationmodelwithafiniteconcentrationofmid-bandgaptrapstatesforself-trappedexcitons.ThephotoinducedconductivitycanbewelldescribedbytheDrude–Smithconductivitymodelwithacarrierscatteringtimeof12–17fs,andweobservesignificantcarrierlocalizationeffects.Afastrefractiveindexchangewasobserved100fsbeforetheconductivityreacheditsmaximum,with2ordersofmagnitudelargeramplitudethanexpectedfortheopticallyinducedTHzKerreffect,indicatingthatfreecarriersareresponsibleforthetransientindexchange.
简介:Chalcopyrite-typeCuInSe2nanoparticlesaresuccessfullypreparedbyusingIn2Se3nanoparticlesasaprecursorreactedwithcopperchloride(CuCl)solutionviaaphasetransformationprocessinlowtemperature.Thereactiontimeisakeyparameter.Afterthereactiontimeincreasingfrom0.5hto8h,In2Se3andCuClreactwitheachothergraduallyviaphasetransformationintoCuInSe2withoutanyintermediatephase.ThecrystallinestructureandmorphologyoftheCuInSe2nanoparticlesarecharacterizedbyX-raydiffraction(XRD)andfieldemissionscanningelectronmicroscopy(FESEM).ThediameterofCuInSe2nanoparticleswithgooddispersibilityrangesfrom10nmto20nm.ThebandgapoftheCuInSe2nanoparticlesis1.04eVcalculatedfromtheultraviolet-visible(UV-VIS)spectrum.
简介:根据刺五加鲨烯合酶基因2(squalenesynthase,SS2)和鲨烯环氧酶基因1(squaleneepoxidase,SE1)的DNA序列,通过Southern杂交和qRT-PCR法确定SS2和SE1的拷贝数。以actin为内参照基因,利用qRT-PCR法和分光光度法确定不同SS2和SE1拷贝数下的基因表达量和皂苷含量。结果表明,刺五加的SS2存在1和2拷贝,SE1存在1、2和3拷贝的类型及其相互组合的6种拷贝数组合基因型。刺五加SS2和SE1的表达量与皂苷含量均随拷贝数的增加而显著提高(p〈0.05),两者间存在极显著的正相关关系(P〈0.01)。SS2和SE1每增加1个拷贝可使皂苷含量分别提高0.57和0.42倍。研究结果为进一步揭示刺五加皂苷含量差异形成的分子机理奠定了基础。
简介:Inthiswork,asimpleandfacileone-potoleylaminesolvothermalsyntheticmethodwasdevelopedtosynthesizeCu_2ZnSnS_4(CZTS)nanocrystals.AndtheCu_2ZnSn(S,Se)_4(CZTSSe)thinfilmswerepreparedbyselenizingCZTSnanocrystals.TheobtainedCZTSnanocrystalsandCZTSSefilmswerestudiedusingX-raydiffraction(XRD),transmissionelectronmicroscopy(TEM),scanningelectronmicroscopy(SEM),energy-dispersiveX-rayspectroscopy(EDX),andultraviolet–visiblespectrophotometer(UV–Vis).TEMresultsshowthatthesphere–likeCZTSnanoparticleswithdiameterbetween12and35nmarepolydispersed.XRDstudiesindicatethatthepreparedCZTSnanocrystalsformkesteritecrystalstructure,andtheCZTSSefilmswithkesteritecrystalstructurearealsoobtainedattheannealingtemperaturesof500and550°C.Inparticularafterannealingat500°Cfor20min,theCZTSSefilmexhibitsasmooth,uniform,crack-free,andlarge-grainedtopographyandpossessesCu-poorandSn-richcomposition.Moreover,itshowsstrongopticalabsorptionfromvisibletonear-infrared(IR)region,anditsopticalbandgap(Eg)isfoundtobeabout1.44eV.