共查询到20条相似文献,搜索用时 46 毫秒
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采用表面压-面积(π-A)等温曲线和紫外-可见吸收光谱研究了三明治型酞菁铽(TbPcPc*)分子在langmuir膜及其langmuir-blodgett(LB)膜中分子的存在状态和光谱特性.实验结果发现TbPcPc*分子在亚相表面可以形成稳定的langmuir膜,在langmuir中以edge-on方式面对面的排列,且具有较好的成膜性能,可以制成多层X型LB膜。TbPcPc*分子在氯仿溶液和LB膜中形成了H-聚集体,形成LB膜后,由于双酞菁分子之间排列紧密,相互作用加强,使得薄膜中分子聚集体的吸收峰相对于溶液中聚集体的吸收峰发生了一定的红移。 相似文献
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本文通过wittig反应合成出了具有两亲性的聚对苯乙撑(PPV)类衍生物,通过核磁和红外对其进行了相关鉴定,并将其铺展上水面上,制得了稳定的单分子膜,并通过计算其单分子面积,研究了其分子在空气/水界面上的取向排列。在对多层LB膜的紫外光谱研究中发现,紫外吸光强度和层数成正比,说明该聚合物的单分子膜在转移过程中膜内分子的取向、构象及堆积方式没有随层数的增加而改变。 相似文献
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采用固相研磨法合成了铕(Ⅲ)-乙酰丙酮配合物,对掺杂聚乙二醇-聚丙烯酸共聚物与铕(Ⅲ)-乙酰丙酮配合物的相互作用及荧光强度的变化进行了对比研究;实验结果表明,掺杂聚乙二醇-聚丙烯酸共聚物的铕(Ⅲ)-乙酰丙酮配合物其荧光强度有了显著地提高。 相似文献
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利用“原住法”合成技术,在EA(双酚A环氧丙烯酸酯树脂)中,合成了稀土荧光配合物Eu(TTA)(AA)2Phen(TTA:噻吩甲酰基三氟丙酮;AA:丙烯酸;Phen:邻菲咯啉),利用红外光谱、紫外一可见光谱和荧光光谱对体系进行了表征。红外光谱的研究表明,配合物在EA体系中的特征吸收峰被基质树脂所掩盖,主要表现为基质树脂的特征吸收;紫外一可见光谱的研究表明,该体系在350nm附近出现配体TTA的强特征吸收,在低于300nm时,吸收峰被基质树脂掩盖;荧光光谱的研究表明,配合物在EA体系中能发出强的铕离子的特征荧光.并且低于铕质量分数为0.4%的范围内,荧光强度与稀土离子含量接近线性关系。 相似文献
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采用表面压-分子面积(π一A)等温曲线和紫外-可见吸收谱的方法研究了一种新型喹吖啶酮衍生物材料LB膜的制备及其光谱特性.实验表明,这种新型喹吖啶酮衍生物能够在水面上形成稳定的单分子膜,它与花生酸(AA)混合后不仅可以形成很好的单分子膜,而且可以较好地转移到固体基片上制备成LB膜多层膜.这种新型喹吖啶酮衍生物LB膜的紫外-可见吸收谱的吸收峰位较稀溶液发生了红移,这是由极性溶剂分子与其相互作用的结果.它在溶液和LB膜中都是以单体的形式存在. 相似文献
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制备了一种含巯基的时间分辨荧光配体BSPDA(4,7-二巯基苯基1,10-菲罗啉-2,9-二羧酸)及其铕(Ⅲ)配合物,研究了铕配合物的荧光性质.结果表明,该巯基配体可与铕(Ⅲ)形成1:1和2:1具有时间分辨荧光特性的配合物,能发射出铕的特征谱线,其1:1与2:1的配合物具有数百微秒以上的荧光寿命,在相关的发射特征峰位处后者的寿命稍长于前者.这表明,在后者铕配合物中存在更强的配位作用和更有效配体对中心离子(即BSPDA到Eu^3+)能量传递. 相似文献
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Eu(1-X)LnX(TTA)3Phen荧光配合物的原位合成和光固化荧光防伪油墨的性能研究 总被引:1,自引:0,他引:1
在EA基质中,合成了Eu(1-X)LnX(TTA)3Phen配合物(Ln=G d、Y和L a,TTA=噻吩甲酰三氟丙酮,Phen=1,10邻-菲咯啉,X=掺杂元素的摩尔分数)。红外光谱的分析表明,配合物的吸收峰被EA(EA=双酚A-环氧丙烯酸酯)基质掩盖,表现为EA的特征吸收;荧光激发光谱、荧光发射光谱的研究表明,在EA基质中Eu(1-X)LnX(TTA)3Phen配合物已经形成,并且表现出强的铕离子特征荧光。荧光体系经固化后的荧光强度明显低于固化前的荧光强度,并讨论了荧光猝灭机理。 相似文献
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SiO_2/稀土Eu(Ⅲ)配合物核-壳复合粒子的制备及发光性能研究 总被引:1,自引:0,他引:1
采用St ber法制备了粒径为40~60nm的单分散纳米SiO2微球,以氧化铕为原料、α-噻吩甲酰三氟丙酮和邻菲啰啉为配体制备了稀土铕的三元配合物,并将其成功包覆在SiO2微球表面,形成核-壳复合粒子。采用红外光谱和元素分析表征配合物的结构。透射电镜照片表明,稀土有机配合物在SiO2微球表面形成了致密的纳米级包覆层,包覆层厚度随配合物用量的增加而增加。复合粒子呈现出很强的Eu配合物发光,纳米SiO2核对配合物有荧光增强作用,但配合物浓度较高时荧光增强效应有所减弱。 相似文献
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《International journal for numerical methods in engineering》2018,113(9):1488-1506
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method. 相似文献
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Standards are the basis for production enterprises to organize production ex-factory inspection trade 《中国标准化(英文版)》2008,25(1):24-25
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.…… 相似文献
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A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa. 相似文献
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On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.…… 相似文献
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Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß. 相似文献
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C. Qihong W. Zhan‐Wen J. Yi J. Yehua L. Fei F. Hanguang 《Materialwissenschaft und Werkstofftechnik》2014,45(7):582-590
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill. 相似文献
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Dimiter Hadjistamov 《材料科学与工程:中英文B版...》2019,(2):56-65
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ... 相似文献
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《中国标准化(英文版)》2014,(4)
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from 相似文献
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《中国标准化(英文版)》2014,(5)
正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively. 相似文献