[1,3,4]-噁二唑衍生物的固相合成及其线性、非线性光谱性质

用固相法合成了2个噁二唑衍生物类有机化合物:5-(4-叔丁基苯基)-[1,3,4]噁二唑-2-苯乙烯基-4-苯基-二苯胺 (化合物1)与9-乙基-3,6-双{5-(4-叔丁基苯基)-[1,3,4] 噁二唑-2-苯乙烯基}-咔唑 (化合物2),并测定了它们的吸收光谱、单光子荧光光谱和双光子荧光光谱.化合物1和2在二氯甲烷溶液中单光子荧光发射峰分别位于519和476nm.在锁模Nd∶YAG激光器800nm激光照射下,化合物1和2发射出很强的双光子上转换荧光,其最大波长分别在520和485nm.     

三苯胺多枝化合物的合成及其荧光性质

采用Heck反应合成了2个三苯胺多枝化合物N,N,N-三{5-(4-叔丁基苯基)-1,3,4-噁二唑-2-苯乙烯基-4-苯基}胺(化合物1)和N,N,N-三[4-{2-(3,5-二-[5-(4-叔丁基苯基)-1,3,4-噁二唑-2-]苯基}-1-乙烯基}苯基}胺(化合物2),并测定了它们的吸收光谱、单光子荧光光谱和双光子荧光光谱.化合物1和2在二氯甲烷溶液中单光子荧光发射峰分别位在536和487nm.在锁模Nd:YAG激光器800nm激光照射下,化合物1和2发射出很强的双光子上转换荧光,其最大波长分别在541和518nm.     

单(噁)二唑席夫碱的合成与光谱研究

4-硝基苯甲酸经酯化和肼解后制得4-硝基苯甲酰肼(2),再与苯甲酰氯反应得到N-苯甲酰基-N’-(对硝基苯甲酰基)-肼(3),(3)在SOCl2存在下脱水环化生成2-苯基-5-(对硝基苯基)-1,3,4-(噁)二唑(4),(4)被Zn/CaCl2还原为2-苯基-5-(对氨基苯基)-1,3,4-(噁)二唑(5),(5)与...     

三阶非线性光学材料甲基噁二唑聚炔合成研究

设计合成了一种含甲基噁二唑功能基的聚炔材料聚(2-对甲基苯基-5-对乙炔基苯基-1,3,4-噁二唑)。对制得的聚合物和单体进行FT-IR、~(1)H-NMR、紫外、荧光和热重(TGA)表征及Z扫描(Z-scan)技术评价,结果表明:聚(2-对甲基苯基-5-对乙炔基苯基-1,3,4-噁二唑)在失重5%时,热分解温度为389℃,较之单体(312℃)有较大提高,热性能较好;非线性吸收系数为-1.53×10~(-10)cm/W,非线性折射率为4×10~(-17)cm~2/W,三阶非线性极化率为3.00×10~(-11)esu,三阶非线性光学性能良好,与侧链烷氧基取代的噁二唑聚炔相比性能显著提高。     

新型三苯胺树枝分子的合成及荧光发射性质

采用Wittig-Horner反应合成了一种新型三苯胺树枝分子1,2,4,5-四{4-{N,N-双{4-{4-[5-(4-叔丁基苯基)-1,3,4-噁二唑-2]苯乙烯基}苯基}氨基}苯乙烯基}苯(TPAB-OXA),并测定了化合物TPAB-OXA在不同溶剂中的紫外吸收光谱、荧光发射光谱及量子产率、荧光寿命.在二氯甲烷中...     

新型聚2,4-二乙烯基3-十二烷基噻吩-1,3,4-噁二唑交替共聚物的合成、表征及性能研究

采用Heck偶合法首次合成了新型的含有空穴传输单元3-十二烷基噻吩和电子传输单元1,3,4-噁二唑的低带隙能的聚2,4-二乙烯基-3-十二烷基噻吩-1,3,4-噁二唑共轭聚合物(P3DDTV-OXD).并且通过1H-NMR、FT-IR、凝胶色谱(GPC)、UV-vis光谱、荧光光谱(PL)、循环伏安(CV)法对所合成的共聚物进行了分析表征.与规整的聚3-十二烷基噻吩均聚物(P3DDT)相比,共聚物的UV最大吸收波长和Pl最大发射波长明显蓝移,具有强烈的蓝色荧光,且电子亲和势较高,同时拥有空穴和电子传输能力,实现了电荷在分子内的双向传输.     

二芳烯类光致变色化合物的合成及其性质

本论文合成了三种新的二芳基乙烯类光致变色化合物1-(2,5二甲基噻吩-3-基),2-[2-甲基-5-(4-甲氧苯基噻吩)-3-基]全氟环戊烯(1a),1-(2,5二甲基噻吩-3-基),2-[2-甲基-5-(4-乙氧苯基噻吩)-3-基]全氟环戊烯(2a),1-(2,5二甲基噻吩-3-基),2-[2-甲基-5-(4-氯苯基噻吩)-3-基]全氟环戊烯(3a),并且研究了它们的光电特性.实验结果表明这些二芳烯化合物在溶液和PMMA膜片中均具有良好的光致变色性能.在313nm紫外灯的照射下,这些二芳烯化合物的溶液和PMMA膜片均由无色变为蓝色,在适当波长可见光照射下,它们均从有色态返回到无色态.在不同的溶液和PMMA膜片中,这些化合物在它们各自的激发波长的照射下均显示出较强的荧光.在313nm紫外灯的照射下,二芳烯由开环态变为闭环态,荧光强度逐渐降低.     

一种含铱共聚物及其性能与应用

采用差示扫描量热法(DSC)和热重分析法(TGA)研究了一种含铱配合物的新型共聚物PVKIr的热性能。结果表明,该聚合物的玻璃化转变温度(Tg)为220.04℃,起始分解温度(Td)为454.31℃,具有良好的热稳定性。利用该聚合物为发光材料制备了电致发光器件ITO/聚(3,4-乙撑二氧噻吩)(PEDOT)(45nm)/2-(4-联苯基)-5-(4-叔丁基苯基)-1,3,4-口恶二唑(PBD):25%PVKIr(80nm)/2,9-二甲基-4,7-二苯基-1,10-菲咯啉(BCP)(15nm)/三(8-羟基喹啉)铝(Alq3)(30nm)/LiF(1nm)/Al,其最大发射峰在532nm,起亮电压为13V。该器件在驱动电压为21V时,达到最大亮度86cd/m2,而此时电流密度为192mA/cm2。     

一种共轭有机杂环分子的双光子吸收与电化学性质

实验研究了一种新的共轭杂环化合物9-乙基-3-{5-(4-叔丁基苯基)-[1,3,4]-噁二唑-2-苯乙烯基}-咔唑(VBPOEC)的双光子吸收性质和电化学性质.双光子吸收截面采用非线性透过率法测定,双光子最大吸收波长位于800nm,吸收截面为1350GM.采用紫外光谱的边带吸收法得到带隙为2.77eV,用循环伏安法对其电化学性质进行了初步研究,氧化电位为1.059V,其HOMO能级为-5.80eV,其LUMO轨道能级为-3.03eV.研究了光学、电化学性质与分子电子结构的关系.     

苯并二噁唑系列聚合物的合成及其光电性能的研究

以4,6-二氨基-1,3-苯二酚盐酸盐为原料,分别与对苯二甲酸、1,4-萘二甲酸、2,6-萘二甲酸、2,5-噻吩二甲酸、4,4’-(1,2-二苯基乙烯)二甲酸、反丁烯二甲酸在多聚磷酸介质中反应,合成了单环的聚(1,4-亚苯基)苯并二噁唑(PBO)、稠环的聚(1,4-亚萘基)苯并二噁唑(1,4-PNBO)和聚(2,6-亚萘基)苯并二噁唑(2,6-PNBO)、杂环的聚(2,5-亚噻吩基)苯并二噁唑(PTBO)、含有两个苯环的聚-4,4’-亚(1,2-二苯乙烯基)苯并二噁唑(4,4’-PDPEBO)和直链烯烃的聚亚乙烯基苯并二噁唑(PBOV)。采用傅立叶红外光谱、元素分析对系列聚合物的结构进行了表征。利用电导率仪和荧光光谱仪,对系列聚合物的结构与性能之间的关系进行了分析。研究结果表明,PBO、1,4-PNBO、2,6-PNBO、4,4’-PDPEBO、PTBO和PBOV电导率依次减小;系列聚合物的荧光发射光谱和激发光谱的形状都相近,聚合物的最大发射峰波长是一致的,其中2,6-PNBO的荧光强度最强。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

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.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

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.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

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.……     

Optimum-Simulation von Ernteprozessen

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.     

A study of centrifugal cast high boron high speed steel

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

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 ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

The Influence of Nitrogen and Boron Implant into Silicon Substrate on the Phase and Internal Stress of c-BN Films

Cubic boron nitride(c-BN) film was deposited on a Si (100) substrate by the RF-magnetron sputtering.The mainly problems for fabrication of c-BN films are the low purity and high intrinsic compressive stress. In order to solve the two problems, the c-BN film with the buffer interlayer was deposited on the substrate which had been implanted with nitrogen and/or boron ions. The results show: the implantation of nitrogen ions can obviously increase c-BN content and reduce the internal stress slightly; while the implantation of boron shows no obvious improvement to the content of c-BN, which can reduce the internal stress in the film obviously. In addition, it is suggested that the implantation of nitrogen and boron shows the best result, which not only can increase the content of c-BN, but also reduce the internal stress in the c-BN film obviously.