第二代太空胡芦巴种子的FTIR研究

采用傅立叶变换红外光谱法(FTIR)对第二代太空胡芦巴与地面组进行对比分析。结果表明,经航空诱变后的胡芦巴种子红外光谱的主要吸收峰的峰位、峰形与地面组的胡芦巴种子基本相同,表明其主要成分和基本结构并未发生变化。但1745cm~(-1)处羰基(C=O)的伸缩振动和1074cm~(-1)处的C-O伸缩振动明显强于地面组,说明太空胡芦巴种子中油脂类及皂苷有效成分含量明显增加;2927cm~(-1)和2855 cm~(-1)处亚甲基CH_2的伸缩振动吸收峰明显强于地面组,说明经太空搭载后亚甲基的振动增强。此外,二阶导数谱显示在1658cm~(-1),1544cm~(-1)处的吸收峰也较地面组的高,说明太空胡芦巴组的蛋白质和氨基酸物质的含量也较高。     

三种紫苏子的红外光谱分析与鉴定

采用红外光谱三级鉴定法和整体解析法对来源地均为河北的三种紫苏子进行分析研究。结果显示:三种紫苏子样品红外光谱中,都有2927,2854,1745,1160 cm~(-1)附近表征油脂类的主要特征峰以及1655和1535 cm~(-1)附近表征蛋白质的主要特征峰。但三种紫苏子油脂与蛋白质特征峰的相对高度差异较大,说明二者在三种紫苏子中的相对含量不同。二阶导数红外光谱中,出现了1709 cm~(-1)附近属于有机酸类的特征峰;此外,三种紫苏子样品在1720~1530 cm~(-1)、1400~1020 cm~(-1)波段的谱峰有显著差异。二维相关红外光谱中,三种紫苏子样品在1400~1800 cm~(-1)、900~1300 cm~(-1)两个波段主要自动峰位置差异不大,不同之处在于自动峰间的相对强度。运用红外光谱三级鉴定和整体解析法可快速、全面分析鉴定三种紫苏子,为紫苏子种质鉴别和紫苏资源的开发利用提供研究思路和方法。     

热输入对X120管线钢焊接接头粗晶热影响区组织和冲击韧性的影响

采用Gleeble-3800型热模拟试验机对X120管线钢进行了焊接热模拟试验,研究了不同焊接热输入下X120管线钢焊接接头粗晶热影响区(CGHAZ)的显微组织和冲击韧性。结果表明:热输入为10kJ·cm~(-1)时,粗晶热影响区组织主要由贝氏体和少量低碳马氏体组成,晶粒间的晶界为小角度晶界;热输入为20kJ·cm~(-1)时,粗晶热影响区的组织由细小的板条贝氏体组成,板条束间为大角晶界;随着热输入的进一步增加,粗晶热影响区的组织主要为粗大的贝氏体,大角度晶界的占比降低;当热输入由10kJ·cm~(-1)增加到40kJ·cm~(-1)时,粗晶热影响区的冲击韧性先增后降,当热输入为20kJ·cm~(-1)时,冲击韧性最好,断裂方式为韧性断裂;热输入为30kJ·cm~(-1)时,断裂方式为脆性解理断裂和韧性断裂共存的混合断裂;热输入为10,40kJ·cm~(-1)时,断裂方式为脆性解理断裂。     

采用计算化学方法解析苯和甲苯红外谱图

本研究应用量子计算化学软件Gaussian 03W HF方法中的3-21G基组优化苯和甲苯分子结构,预测苯和甲苯分子的红外光谱。找到苯环振动吸收峰分别是苯红外图中的1658 cm~(-1)与甲苯红外图中的1667 cm~(-1)。与苯和甲苯文献检索红外谱图相对应(特征吸收峰分别是1478和1485 cm~(-1)),符合较好。还找到苯环C-H拉伸振动吸收峰3080cm~(-1)(苯)和3040 cm~(-1)(甲苯)。能够实用于红外法检测环境中苯和甲苯。     

葡萄酒的红外光谱快速分析

运用一维红外光谱结合其二阶导数谱对5种不同类型的葡萄酒样品进行了快速分析。在葡萄酒的一维红外谱图上,干型和甜型葡萄酒的主要区别是酒精特征峰1 044和1 085 cm~(-1)处峰强度和峰位置的不同。在二阶导数谱上,细微差别被放大,1 250～950 cm~(-1)之间糖类特征峰变得明显,且随着含糖量的提高,1 158、1 131、1 107、1 065、1 014、992、965和921 cm~(-1)等位置糖类C-O键的特征峰的数量和强度亦相应增加。根据上述特征,可直接对葡萄酒进行定性和半定量的分析。结果表明,对于葡萄酒的分析鉴定,红外光谱是一种快速、直接、有效的方法。     

真伪天麻二维相关红外光谱法的鉴别研究

本文采用红外光谱法并结合二维相关(Two-Dimensional Correlation Spectroscopy)分析技术,对药用天麻和伪品天麻(芭蕉芋)进行了无损快速鉴别研究。天麻和芭蕉芋在外观上很相似,都是成椭圆或扁卵圆形的块茎,皱缩而稍弯曲,并且在一维谱图上差别很细微,而在二维谱图上显示出较大的差别。在800～1500cm~(-1)波段范围内,天麻在同步图上有二个较强的自动峰,分别在1237cm~(-1)和1415cm~(-1)附近,而芭蕉芋有四个较强的自动峰,在1024、1055、1194、1225cm~(-1)附近,1400cm~(-1)处也有相关峰,但是较微弱,二维相关谱可以提高谱图的分辨率,增加谱图的识别能力,可用于药材真伪品的鉴别。该法快速、准确,为客观评价中药材的来源提供了一种新的方法和手段。     

系列讲座:德国蔡司公司光学仪器的使用与保养(2)

<正> 1.3.关于狭缝系统 狭缝系统是保证分光光度计分辩率和能量的关键部件。SPECORD 75IR采用双光路光学零位平衡原理进行测量,光路安排如图1所示: 入射狭缝和出射狭缝按照预置的狭缝程序变化,该程序由一块与主轴联动的凸轮确定,在4000cm~(-1)和400cm~(-1)时开启到最大,在2000cm~(-1)～800cm~(-1)时关到最小,这样确保能量在整个光谱区域内分布均匀。同时狭缝的初始宽     

热输入对双相钢药芯焊丝电弧焊接头组织和性能的影响

对2205双相不锈钢板进行了药芯焊丝电弧焊,研究了不同热输入(8.32,11.02,14.04,17.39kJ·cm~(-1))对焊接接头显微组织、铁素体含量、冲击性能、显微硬度和耐点腐蚀性能的影响。结果表明:2205双相不锈钢接头焊缝、熔合区及热影响区均由奥氏体和铁素体组成,铁素体含量随着热输入的增加而逐渐降低;焊接热输入在14.04kJ·cm~(-1)时,接头区域铁素体体积分数基本满足40%～60%的要求;随着焊接热输入的增加,接头焊缝和热影响区的硬度略有降低,焊缝金属的冲击吸收功先升高后下降,热影响区的点腐蚀速率变化不大,焊缝的点腐蚀速率则先下降后升高;焊接热输入在14.04kJ·cm~(-1)时,2205双相不锈钢焊接接头的耐点腐蚀性能最好。     

硅基BiFe_(0.95)Mn_(0.05)O_3/Pb(Zr_(0.4)Ti_(0.6))O_3/BiFe_(0.95)Mn_(0.05)O_3集成薄膜的结构及其铂电极电容器的性能

用溶胶-凝胶法在Pt/Ti/SiO_2/Si(001)基片上制备了BiFe_(0.95)Mn_(0.05)O_3/Pb(Zr_(0.4)Ti_(0.6))O_3/BiFe_(0.95)Mn_(0.05)O_3(BFMO/PZT/BFMO)集成薄膜,采用X射线衍射仪分析了其物相结构;采用铁电测试仪考察了该集成薄膜与铂极构成的铁电电容器的性能。结果表明:该集成薄膜结晶较好,除BFMO、PZT及基片的衍射峰外没有其它衍射峰存在;当电场强度为0.7 MV·cm~(-1)时,Pt/BFMO/PZT/BFMO/Pt电容器的电滞回线对称性良好,剩余极化强度为17.9μC·cm~(-2),矫顽力为0.12 MV·cm~(-1);在电场强度为0.4 MV·cm~(-1)下测得的铁电电容器漏电流密度为2×10~(-5)A·cm~(-2),电容器在经过10~(10)次反转后未出现明显的疲劳现象。     

小型巡回检测仪与计算机的接口

微计算机的应用日益广泛,许多已在现场运行的小型巡回检测仪需要作为输入通道接入微计算机。一般对原巡回检测仪不做大的变动,附加必要的接口电路完成与计算机的连接。由于各巡回检测仪采用的元器件不同,与微计算机的接口也就不同。下面介绍一种巡回检测仪与计算机的接口电路。巡回检测仪的组成用集成电路CH_(7555)、SCL_(402)、CH_(4051)、CC_(4052)和CH_(7106)可方便地组成巡回检测仪,XSW-10数字式温度巡测仪就是其中一例,原理图如图1所示。     

原油分离物的红外光谱分析

本文利用红外光谱对大庆原油分离物进行分析,研究各分离物可能存在的官能团及其分离物的相对极性,研究了各分离物CH_2/CH_3比值,为原油的改性研究奠定了基础。     

范德华力对硅基微悬臂梁抗粘附稳定性的影响

通过在硅微悬臂梁与基底表面上涂覆低表面能的憎水性OTS(CH3(CH2)17SiCl3)膜,以除去接触面间的表面张力;把梁与基底均接地,以除去接触面间的静电力,研究仅有范德华力作用时,硅微悬臂梁结构的抗粘附稳定性.根据两接触面均为粗糙表面的微观实际接触模型,在接触表面产生塑性变形的情况下,计算范德华粘附能大小,并分析表面形貌对其影响,得到粗糙表面接触的微梁抗粘附临界长度.     

表面修饰剂的亲油链长度对纳米氟化镧摩擦学性能的影响

以亲油基链长度不同的十二酸二乙醇胺、十四酸二乙醇胺、十六酸二乙醇胺及十八酸二乙醇胺为表面修饰剂,在醇-水体系中制备了4种纳米氟化镧粒子,通过透射电镜（TEM）、红外光谱（FTIR）、热重仪（TG）研究了纳米氟化镧粒子的形貌及表面修饰情况,利用四球机研究了亲油链长度对纳米氟化镧粒子的摩擦学性能及对基础油感受性的影响。结果表明：随着表面修饰剂烷基链长度的增长,纳米LaF3粒子在基础油中摩擦学性能呈现出逐渐增强的趋势;亲油链越长,纳米粒子在液体石蜡中的摩擦学感受性比500SN基础油中更好。这主要是因为亲油基链的长度影响了纳米粒子的界面活性,而且同系有机酸皂类物质,亲油基碳链越长,其减摩作用也越好;基础油的性质影响了纳米粒子的界面活性。     

Chemical force microscopy of self-assembled monolayers on sputtered gold films patterned by phase separation

Patterned self-assembled monolayers (SAMs) were formed on gold films and observed by friction force microscopy (FFM) and adhesive force mapping with pulsed-force mode atomic force microscopy (PFM-AFM). The substrate gold films were prepared by sputtering gold on flat surfaces of osmium-coated cover glass with surface roughness, Ra, of 0.3 nm. The patterned samples with the CH3 and COOH terminated regions were prepared using the Langmuir-Blodgett (LB) method, partial removal of the LB film by ultrasonication, and SAM formation. The CH3 and COOH terminated regions of the patterned SAMs in air and in water were observed by mapping friction and adhesive forces with FFM and PFM-AFM, respectively, using gold-coated AFM tips chemically modified with a thiol compound terminating in CH3 or COOH. The adhesive forces measured in air increased in the order of CH3/CH3, CH3/COOH (or COOH/CH3) and COOH/COOH, while those in water increased in reverse order. The enormous high adhesive force observed in water for CH3/CH3 was attributed to hydrophobic interaction between the CH3 tip and the CH3 terminated sample surface. With CH3 tip, the lower friction force was observed, however, in water on the CH3 terminated region than on the COOH terminated region. This experimental finding raises a question as to what is the effective normal load in friction measurements in water.     

油酸在齿轮切削加工润滑油中的应用研究

以油酸和正丁醇、乙二醇为原料合成的油酸丁酯、油酸乙二醇酯混合物,具有优良的润滑性和良好的耐磨性,添加 在齿轮切削油中,不仅可使工件的加工质量显著提高,同时延长了齿轮刀具的使用寿命。     

A rigid, monolithic but still scannable cavity ring-down spectroscopy cell

A novel cell for continuous wave cavity ring-down spectroscopy (cw-CRDS) is described and tested. The cell is monolithic and maintains a rigid alignment of the two cavity mirrors. Two high-resolution and high-force piezoelectric transducers are used to sweep the length of the cell by elastic deformation of the 2.86 cm outer diameter stainless steel tube that makes up the body of the cell. The cavity length is scanned more than 1/2 wavelength of the near-IR light used, which ensures that at least one TEM(00) mode of the cavity will pass through resonance with the laser. This allows the use of a frequency-locked-laser cw-CRDS technique, which increases the precision of the measurements compared to the alternative of sweeping the laser more than one free spectral range of the cavity. The performance of the cell is demonstrated by using it to detect the absorption spectrum of methane (CH(4)) at the wavenumber regions of around 6051.8-6057.7 cm(-1).     

Fiber optic sensing technology for detecting gas hydrate formation and decomposition

A fiber optic-based distributed sensing system (DSS) has been integrated with a large volume (72 l) pressure vessel providing high spatial resolution, time-resolved, 3D measurement of hybrid temperature-strain (TS) values within experimental sediment-gas hydrate systems. Areas of gas hydrate formation (exothermic) and decomposition (endothermic) can be characterized through this proxy by time series analysis of discrete data points collected along the length of optical fibers placed within a sediment system. Data are visualized as an animation of TS values along the length of each fiber over time. Experiments conducted in the Seafloor Process Simulator at Oak Ridge National Laboratory clearly indicate hydrate formation and dissociation events at expected pressure-temperature conditions given the thermodynamics of the CH(4)-H(2)O system. The high spatial resolution achieved with fiber optic technology makes the DSS a useful tool for visualizing time-resolved formation and dissociation of gas hydrates in large-scale sediment experiments.     

Acetonitrile (CH3CN) and methyl isocyanide(CH3NC)adsorption on Pt(111) surface: a DFT study

The adsorption of CH3CN and CH3NC on the Pt(111)surface at the 1/4 monolayer(ML)coverage has been carried out at the level of density functional theory for understanding hydrogenation processes of nitriles.The most favored adsorption structure for CH3CN is the C-N bond almost parallel to the surface with the C-N bond interaction with adjacent surface Pt atoms.For CH3NC,the most stable configuration is the CH3NC locates at the face center cubic(fcc)site with the C-atom bonded to three Pt atoms.In addition,the HCN and HNC adsorption has been computed,and the adsorption pattern is nearly similar to the CH3CN and CH3NC,respectively.The adsorbed molecules rehybridize on the surface,becoming non-linear with a bent C-C-N or C-N-C angle.Furthermore,the binding mechanism of these molecules on the Pt(111)surface is also analyzed.     

Determination of polychlorinated dibenzo-p-dioxins,dibenzofurans, and biphenyls by gas chromatography/mass spectrometry in the negative chemical ionization mode with different reagent gases

Reagent gases that are used in mass spectrometry in the NCI mode for the determination of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) are discussed. Ion-molecule reactions and respective characteristic ions that form while using reagent gases (CH(4), O(2), i-C(4)H(10), NH(3), H(2), He, Ar, Xe, SF(6)) or gas mixtures (CH(4)/O(2), Ar/CH(4), CH(4)/H(2)O, Ar/O(2), i-C(4)H(10)/CH(2)Cl(2)/O(2)) are reviewed. It is shown that only CH(4), O(2), CH(4)/O(2), and CH(4)/N(2)O are widely used and well studied, even though-in the case of these reagent gases-there are contradictions between the publications of various authors. Such reagent gases as NH(3) and He are not well studied, but further investigations of their use for the determination of organochlorine pollutants could be of interest. The possibilities of more sensitive and selective determination of PCDDs, PCDFs, and PCBs are discussed.     

Measurement of three-dimensional flame structure by combined laser diagnostics

To investigate three-dimensional flame structures of turbulent premixed flame experimentally, dual-plane planar laser induced fluorescence (PLIF) of CH radical has been developed. This dual-plane CH PLIF system consists of two independent conventional CH PLIF measurement systems and laser beam from each laser system are led to parallel optical pass using the difference of polarization, and CH PLIF is conducted in two parallel two-dimensional cross sections. The newly-developed dual-plane CH PLIF is combined with single-plane OH PLIF and stereoscopic particle image velocimetry (PIV) to clarify the relation between flame geometry and turbulence characteristics. The laser sheets for single-plane OH PLIF and stereoscopic PIV measurement are located at the center of two planes for CH PLIF. The separation between these two planes is selected to 500 μm. The measurement was conducted in relatively high Reynolds number methane-air turbulent jet premixed flame. The experimental results show that various three-dimensional flame structures such as the handgrip structure, which has been shown by three-dimensional direct numerical simulations (DNS), are included in high Reynolds number turbulent premixed flame. It was shown that the simultaneous measurement containing newly-developed dual-plane CH PLIF is useful for investigating the three-dimensional flame structures. To analyze the flame structures quantitatively, the flame curvature was estimated by using the CH and OH PLIF images, and the probability density function (pdf) of the curvatures was compared with the results of DNS. It was revealed that the minimum radius of curvature of the flame front coincides with Kolmogorov length. However, the feature of pdf of the flame curvature is slightly different from result of DNS, if the curvature was estimated from experimental results in two-dimensional cross section. On the other hand, the feature of pdf of mean curvature that calculated from triple-plane PLIF results is similar to that obtained from three-dimensional DNS. This paper was presented at the 7th JSME-KSME Thermal and Fluids Engineering Conference, Sapporo, Japan, October 2008. Takashi Ueda received his B.S. degree in Mechano-Aerospace Engineering from Tokyo Institute of Technology, Japan, in 2008. Mr. Ueda is currently in Master course at Department of Mechanical and Aerospace Engineering, Tokyo Institute of Technology, Tokyo, Japan. Mr. Ueda’s research interests include turbulent combustion. Masayasu Shimura received his B.S. degree in Mechano-Aerospace Engineering from Tokyo Institute of Technology, Japan, in 2005. He then received his M.S. from Tokyo Institute of Technology in 2006. Mr. Shimura is currently in Ph.D candidate at Department of Mechanical and Aerospace Engineering, Tokyo Institute of Technology, Tokyo, Japan. Mr. Shimura’s research interests include noise control of turbulent combustion. Mamoru Tanahashi received his B.S. degree in Mechanical Engineering, Science from Tokyo Institute of Technology, Japan, in 1990. He then received his M.S. and Dr. Eng. from Tokyo Institute of Technology in 1992 and 1996, respectively. Prof. Tanahashi is currently an Associate Professor of Department of Mechanical and Aerospace Engineering, Tokyo Institute of Technology, Tokyo, Japan. Prof. Tanahashi’s research interests include turbulence and combustion. Toshio Miyauchi received his B.S. degree in Mechanical Engineering from Tokyo Institute of Technology, Japan, in 1971. He then received his M.S. and Ph.D. degrees from Tokyo Institute of Technology in 1973 and 1981, respectively. Prof. Miyauchi is currently a Professor of Department of Mechanical and Aerospace Engineering, Tokyo Institute of Technology, Tokyo, Japan. Prof. Miyauchi’s research interests include turbulence and combustion.