N-(苯并环丁烯-4-基)马来酰亚胺的制备及热稳定性

对N-(苯并环丁烯-4-基)马来酰亚胺原有文献的合成方法进行了改进,在温和条件下使该单体产率有所提高。研究了该单体分别与苯乙烯和N-苯基马来酰亚胺在溶液中的二元共聚反应,对所得的共聚物进行表征,并对其热性能进行了分析。结果表明,N-(苯并环丁烯-4-基)马来酰亚胺的均聚物具有很高的热分解温度,初始分解温度为400℃,480℃的热失重仅为10%,将其与苯乙烯共聚可显著提高苯乙烯的耐热性,有望用于高性能复合材料的树脂基体。     

两种有机化合物DMAHAS和DMANHAS的合成、表征和非线性光学性质

合成了两个有机化合物：反式-4-(N-羟乙基-N-乙基胺基)-4′(二甲基胺基)二苯乙烯(简称DMAHAS)和反式-4-[N-(乙基4″-硝基苯甲酰基)-N-乙基胺基]-4′-(二甲基胺基)二苯乙烯(简称DMANHAS)。用核磁、红外光谱以及元素分析进行了表征。测试了紫外吸收光谱、单光子荧光光谱和双光子荧光光谱。在800nm的飞秒脉冲激光的激发下，DMAHAS发出较强的蓝紫色上转换荧光。荧光峰位于430nm。而在相同条件下DMANHAS的荧光淬灭。     

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...     

4-马来酰亚胺基取代邻苯二甲酰亚胺的合成研究

以4-氨基邻苯二甲酰亚胺和马来酸酐为原料,分别采用两步法和一步法合成了4-马来酰亚胺基取代邻苯二甲酰亚胺,探索了两种合成方法的最佳工艺条件,并通过红外光谱(FT-IR)、核磁共振氢谱(~1 H-NMR)对中间产物和目标产物进行了结构表征。分别采用两步法和一步法合成了4-马来酰亚胺基取代邻苯二甲酰亚胺,并对两种合成方法的工艺条件进行了优化。实验结果表明:采用一步法合成4-马来酰亚胺基取代邻苯二甲酰亚胺的最佳工艺条件为:甲苯与N,N-二甲基甲酰胺(DMF)为共溶剂的体积配比为1∶1,4-氨基邻苯二甲酰亚胺用量0.005mol,马来酸酐用量0.006mol,快速加热到120℃下反应,制得的4-马来酰亚胺基取代邻苯二甲酰亚胺的产率可达60.3%。由于一步法可对反应溶剂甲苯进行回收,相比两步法生产成本低。     

溶剂效应对Cycl[3,2,2]azine类化合物光谱性能的影响

合成了4个不同取代基的Cycl[3,2,2]azine类化合物,首次研究了溶剂效应对其紫外光谱和荧光光谱的影响,发现这4种化合物在极性较大的乙醇和DMF溶剂中的紫外吸收峰值都比较大,而在乙醇和DMF溶剂中的荧光也都比较强.溶剂效应对这些化合物的紫外吸收波长扣荧光发射波长无明显的影响,表明这些化合物对环境有这良好的适应性.这些化舍物在蓝光区均能发射强烈的荧光,有望作为难得的蓝光区荧光材料.     

用飞秒Ti：sapphire激光测定对称型化合物的双光子吸收和上转换荧光

用800nm波长的飞秒Ti:sapphire激光测定了2个对称型噁二唑衍生物2,5-二[4-(2-N,N-二苯氨基苯乙烯基)苯基]-1,3,4-噁二唑(PASPO)与2,5-二[4-{2-N,N-二(4-溴代苯)氨基苯乙烯基]苯基}-1,3,4-噁二唑(BrPASPO)的双光子吸收和双光子激发荧光光谱,其飞秒双光子吸收截面为20.6和9.91GM,双光子泵浦上转换荧光最大波长分别在535和545nm.测定了紫外吸收、荧光光谱,研究了化合物在不同溶剂中的溶致变色效应.化合物PASPO和Br-PASPO在二氯甲烷溶液中的吸收峰分别位于412和403nm,荧光发射峰分别位于511和495nm,荧光量子产率分别为0.73和0.70.     

马来酸酐——苯乙烯交替共聚物氨解产物膜表面性质研究

测定了Ｎ－对本基马来酰亚胺与苯乙烯、乙酸乙烯酯、甲基丙烯酸甲酯共聚物膜的动态接触角（ＤＣＡ），得出表面的极性顺序为ｃｏｐｏｌｙｍｅｒＩ〈ｃｏｐｏｌｙｍｅｒⅡ〈ｃｏｐｏｌｙｍｅｒⅢ。这与其共聚单体的侧基的极性顺序一致，另外，将马来酸酐与苯乙烯共聚物与５种不同取代芳胺进行氨解反应，成膜后用ＤＣＡ法并结合ＥＳＣＡ测定膜的表面性质。实验结果表明，氨解产物在ＤＭＦ中成膜后，膜表面Ｎ／Ｃ含量比明显高于本体，由     

1,2,4,5-四取代苯的合成与荧光性质

通过Wittig-Horner反应合成了两个四取代苯:1,2,4,5-四(4-N,N-二苯氨基苯乙烯基)苯 (TDASB)和1,2,4,5-四[4-N,N-二(4-溴苯基)氨基苯乙烯基]苯(TDBSB).目标化合物结构经过红外光谱、核磁共振谱、质谱和熔点确证,测定了它们在不同溶剂中的紫外光谱和荧光光谱.TDASB 和TDBSB在二氯甲烷中的最大吸收峰分别位于400和396nm,最大发射峰分别为493和491nm,荧光寿命分别为1.7022、3.633和1.2810、4.8473ns,讨论了Stokes位移与溶剂极性的关系.     

一种含磺酸基席夫碱荧光探针的合成及性质

合成了一种含磺酸基席夫碱。通过核磁、红外光谱对其结构进行了表征,研究了其在不同溶剂中的紫外可见吸收光谱和荧光发射光谱及对过渡金属离子的识别。结果表明:在不同溶剂中紫外最大吸收波长发生红移,荧光最大发射波长发生蓝移,在丙酮和DMF(N,N-二甲基甲酰胺)溶剂中荧光发生猝灭;该席夫碱作为荧光探针分子对Fe~(3+)和Cu~(2+)有良好的识别作用。     

含柔性酯基的N-取代马来酰亚胺的合成及溶液聚合

以马来酸酐(MA)、氨基丙酸(Aln)、直链醇为原料,选择合适的溶剂、催化剂,通过三步两釜法合成了侧链含柔性酯基的N-取代马来酰亚胺单体(RAM);以自由基溶液聚合法进行了均聚和共聚;利用IR、TG、DTA对产物(PRAM)进行了表征;并讨论了侧链长度对均聚物溶解性能、热性能的影响,结果表明柔性链长度对溶解性、起始热分解温度影响不大,但玻璃化温度(Tg)随柔性链增长而明显下降。     

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.     

Brainstorming for ISO Strategy 2016-2020

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