铈对2090铝锂合金织构和力学性能的影响

为了解Ｃｅ对铝锂合金力学性能各向异性的影响,对不同Ｃｅ含量２０９０铝锂合金织构进行了ＯＤＦ（取向分布函数）测算,对合金不同方向性能进行了测量,分析了Ｃｅ对合金 构和力学性能的影响。２０９０铝锂合金主织构类型为（２２５〈５５４〉,Ｃｅ不改变合金主织构类型,但造成主织构类型分布漫散;由于Ｃｅ降低了蛔屈服强度各向异性织构成分的含量,故Ｃｅ可改变２０００铝锂合金理想织构成分的体积分数,减小屈服强度各向异性     

Cu－Zn－A1形状记忆合金板材的织构与弹性各向异性研究

本研究采用织构分析的三维取向分布函数法（ＯＤＦ）研究了Ｃｕ－Ｚｎ－Ａ１形状记忆合金的织构与弹性各向异性。研究结果表明：１．两相Ｃｕ－Ｚｎ－Ａｌ合金板材β－相的构与钢板相似，它在欧拉空间系由Ａ－管和Ｂ－管纤维织构组成的；而α－相的织构与冷轧黄铜板的织构相似。２．板材表面与内部的织构具有一定的差别，对于β－相的织构，这种差异明显；而对于α－相的织构只是强弱之差。３．弹性模量随与轧向偏离的角度而变，对于具有β－相的板材，在与轧向４５°方向的板材的弹性模量呈极小值，这与β－相合金具有较大的弹性各向异性因子有关，但对于α－相弹性模量随角度的变化不明显。该合金具有较大的弹性各向异性有利于马氏体相变。     

表面氧化外延制备钇系涂层导体隔离层

采用表面氧化外延(SOE)方法, 在金属基底上研制NiO隔离层. 通过研究温度、时间等工艺参数对形成立方织构NiO的影响, 摸索出一套可获得单一、尖锐的立方织构NiO, 重复性好, 适合于长带发展的工艺技术. 同时研究了金属基带的表面状态、织构取向对NiO(100)表面的影响. X射线极图观测可直观地看到单一的立方织构, φ扫描检测其半高宽(FWHM)均为7.5°. 扫描电镜观察NiO(100)膜层表面形貌, 无裂纹且较为致密.     

反应溅射法在立方织构镍基底上制备CeO2缓冲层

采用反应溅射的方法在具有立方织构的Ni基底上制备了 CeO2缓冲层.以Ar/H2混合气体为预沉积气体,有效地抑制了基底的氧化.在基片温度为650 ℃,气压为26 Pa的条件下沉积的CeO2薄膜具有纯c轴取向.X射线θ-2θ扫描、极图分析、Φ扫描结果表明,CeO2薄膜有良好的立方织构,其Φ扫描半高宽(FWHM)为9.0°.扫描电镜观察表明,薄膜致密且没有裂纹.     

早期复极综合征与锌的关系：附20例分析

分析了２０例早期复极综合征患者血锌，发现比正常值偏低。早期复极综合征可能与植物神经功能系统的微量元素平衡障碍有关。     

芳香共聚酯B-N多种向列织构的形态研究

从一种聚芳酯B-N得到了丝状(包括细丝和粗丝)、纹影状和大理石纹状等与小分子向列液晶相似的多种织构。由于样品淬火后晶片装饰在织构上而不影响分子取向矢的分布,因而可以用化学刻蚀和电镜技术揭示其向错和取向矢图。电镜和光学显微镜的结果相互补充,表明了细丝和粗丝状织构的分子取向矢分布很不相同,是两种不同的织构,而粗化始于第二熔融降温。在这些向列织构中分别发现了S=±(1/2)和s=+1的向错的例子和平面内微区转向壁的证据。     

芳香共聚酯B-N多种向列织构的形态研究

 从一种聚芳酯B-N得到了丝状(包括细丝和粗丝)、纹影状和大理石纹状等与小分子向列液晶相似的多种织构。由于样品淬火后晶片装饰在织构上而不影响分子取向矢的分布,因而可以用化学刻蚀和电镜技术揭示其向错和取向矢图。电镜和光学显微镜的结果相互补充,表明了细丝和粗丝状织构的分子取向矢分布很不相同,是两种不同的织构,而粗化始于第二熔融降温。在这些向列织构中分别发现了S=±(1/2)和s=+1的向错的例子和平面内微区转向壁的证据。     

在多晶金属基片上制备双轴织构YSA膜

采用调制偏压射频控溅射技术在多晶Ｈａｓｔｅｌｌｏｙ－Ｃ金属基带上制备钇稳定的ＺｒＯ２薄膜（ＹＳＺ），得到了ｃ－轴织构和部分平面内双轴织构的ＹＳＺ薄膜。用Ｘ射线衍射θ－２θ扫描、ω扫描和φ扫描对ＹＳＺ薄膜的织构进行了测量，并研究了沉积条件对织构形成的影响。     

FRS-XRSA表征双轴取向聚对苯二甲酸乙二酯薄膜的取向分布

Ｘ－射线散射理论分析（ＦＲＳ－ＸＲＳＡ）是作者为了研究和表征取向高聚物结晶度与晶粒取向分布（ＯＤＣ）的一种新方案．在表征ＯＤＣ方面应用分峰法（ＣＰＲ）消除了传统极图法（ＰＦＭ）中高重叠峰相互干扰的困难，克服了取向分布函数分析（ＯＤＦＡ）中出现虚织构的困难，并且经一次系统的ＦＲＳ－ＸＲＳ测定，可以得到几乎所有主要（ｈｋｌ）晶面法向的ＯＤＣ．作者应用ＦＲＳ－ＸＲＳＡ对二类双轴取向ＰＥＴ磁带薄膜进行了ＯＤＣ的研究。基于结晶几何学原理（ＣＧＰ），建立了三斜晶系晶粒坐标系与试样坐标系的关系，并用于推演未测定方位角（αｉ，βｉ）（ｈｋｌ）的晶面散射以及未测（ｈ′ｋ′ｌ′）晶面的ＯＤＣ．作者关系建立了双轴取向函数〈ｃｏｓ２φｈｋｌ，ｉ〉，ｉ＝Ｎ、Ｍ、Ｔ的计算公式．按照ＦＲＳ－ＸＲＳＡ获得了反映取向分布的１０个晶面的双轴极图、三个主晶面（１００）、（０１０）、（１０５）的总极图，以及反映平均取向的各种取向函数，如〈ｃｏｓ２φｈｋｌ，ｉ〉、ｆｃｈｋｌ，ｉ等，结果十分令人满意．     

在多晶金属基片上制备双轴织构YSZ膜

采用调制偏压射频磁控溅射技术在多晶ＨａｓｔｅｌｏｙＣ金属基带上制备钇稳定的ＺｒＯ２薄膜（ＹＳＺ），得到了ｃ轴织构和部分平面内双轴织构的ＹＳＺ薄膜。用Ｘ射线衍射θ２θ扫描、ω扫描和扫描对ＹＳＺ薄膜的织构进行了测量，并研究了沉积条件对织构形成的影响。     

Growth mechanism of textured MgO thin films via SSCVD

Magnesium oxide thin films have been deposited with use of single source chemical vapor deposition (SSCVD). The resultant films were examined by using transmission electron microscopy, X-ray texture analysis, and pole figure analysis. Due to the nature of the chemical reactions occurring at the surface during SSCVD growth, which result in a high growth rate/low flux environment, films of (111) orientation have been achieved without an amorphous underlayer, an unusual result for films of this orientation. Moreover the films have a strong degree of biaxial texturing in the x-y plane as found with X-ray texture analysis. These findings have important implications for buffer layers in perovskite thin film devices. The mechanism producing these structures has been revealed by using TEM and is discussed here.     

Texture development in polyethylene II. Unidirectional rolling

The effect of degree of strain on texture development in high-density polyethylene has been studied by pole figure analysis for unidirectional rolling. The crystallite orientation distribution in rolling textures has been quantified with an efficient technique which fits three-parameter, two-dimensional Gaussian-type distributions to pole figure intensity data around ideal single crystal orientations. During flat rolling of polyethylene a texture consisting of a strong (100) [001] component and a weak (110) [001] component develops continuously from the lowest true strain of 0.24 (21% reduction) up to the highest true strain of 1.36 (74% reduction). The peak intensity of the Gaussian distributions of both (100) [001] and (110) [001] components increase continuously to the highest strain. The maximum angular breadth of both component distributions, which are roughly perpendicular to the strain direction, remains constant with increasing strain. The minimum angular breadth of both component distributions, which are roughly parallel to the strain direction, decreases continuously owing to gradual alignment of the covalently bonded chain backbone parallel to the strain direction. The development of the (100) [001] component is explained by slip on (100) planes while the weak (110) [001] component is explained by slip on (110) planes. Although the latter component was previously attributed to (110) or (310) relaxation twinning, this seems unlikely because of the lateral constraint during plane strain deformation conditions used in this study.     

热轧对涂层导体用镍基带立方织构形成的影响

热机械加工制备的立方织构Ni及其合金带材广泛用于YBCO涂层导体的基带。涂层导体的制备要求基带具有强的立方织构和小的晶界角。通过在冷轧前进行热轧制备了强立方织构的镍基带。用三维取向分布函数（ODF）研究了轧制织构和再结晶织构，通过扫描电镜EBSD的观测，分析了晶粒取向分布和立方织构晶界微取向角分布。结果表明，冷轧前进行热轧有利于形成很强的立方织构和小的晶界微取向角。     

Rheological behavior of fiber suspensions in a turbulent channel flow

Rheological behavior of fiber suspensions in a turbulent channel flow was investigated theoretically and numerically. A model of turbulent fiber suspensions was proposed to predict the orientation distribution of fibers. The fluctuating equation for the orientation distribution function (ODF) of fibers was theoretically solved using the method of characteristics. The self-governed mean equation for orientation distribution function (ODF) was derived by relating the fluctuating ODF and angular velocities-correlated terms to the gradient of mean ODF. Then the ODF of fibers was predicted by numerically solving the mean equation for ODF. Finally the shear stress and first normal stress difference of suspensions were obtained. The results, some of which agree with the available relevant experimental data, show that the orientation distribution of fibers in the vicinity of the center of the flow is relatively broad in turbulent regime, and becomes broader with the increase of Reynolds number. The shear stress of fiber suspensions increases, while the first normal stress difference decreases, from the wall to the center of the flow for varying Reynolds number.     

Low density polyethylene-montmorillonite nanocomposites for film blowing

Low density polyethylene nanocomposites were prepared using differently modified montmorillonite (MMT) and different compatibilizers. The best results were obtained for MMT with largest gallery distance. The most exfoliated system was further optimized for superior mechanical properties by varying the compounding condition. The criteria were mechanical properties of nanocomposites and X-ray proofs of exfoliation. The optimized nanocomposites were used for film blowing. The effect of blow ratio on mechanical properties and oxygen permeation of films was evaluated for two best nanocomposites and two films blown from pristine polyethylene. The texture of crystalline phase of blown films was analyzed by X-ray pole figure technique, SAXS and AFM. Two components of texture were detected, the first component related to the molecular orientation of polyethylene by film blowing and take-up and the second connected with the formation of free surfaces of the film. The crystallinity degree from DSC and long period determined from SAXS of polyethylene component were nearly independent of the additives. It indicated that the compatibilizer was preferentially located around clay platelets and did not enter the amorphous layers of polyethylene. Also the orientation of clay platelets was determined by FTIR using 1080 cm⁻¹ band characteristic for Si-O bonds. A clear correlation of oxygen permeativity of blown films with clay platelets orientation and degree of exfoliation was evidenced.     

Crystalline orientation of the InN films prepared by atmospheric pressure halide chemical vapor deposition

The structural analysis of the hexagonal InN film prepared on a Si(100) substrate by the AP-HCVD technique using InCl₃ and NH₃ as starting materials were carried out by the X-ray pole figure analysis. The deposited films consist of the hexagonal InN pillar crystals. It was found that the pillar crystals, which have random rotation around the 100 axis, were grown at an angle of 70–90° to the substrate.     

Proton field-cycling nuclear magnetic resonance relaxometry in the smectic A mesophase of thermotropic cyanobiphenyls: Effects of sonication

Proton field-cycling nuclear magnetic resonance relaxometry is used to study the spin-lattice relaxation dispersion of selected standard smectic A liquid crystals at different temperatures. Relaxation features at both, in the presence and absence of a monochromatic ultrasonic field are considered. We show that the laboratory-frame spin-lattice relaxation time is mainly governed by translational diffusion. Order director fluctuations (ODF) are less important while rotational diffusion seems to be only relevant near the clearing point. Our study suggests that sonication enhances the ODF contribution in the SmA mesophase. Within the framework of the approach we have outlined, different features associated with the ODF mechanism can be investigated.     

Pattern‐Based Detection of Toxic Metals in Surface Water with DNA Polyfluorophores

Heavy metal contamination of water can be toxic to humans and wildlife; thus the development of methods to detect this contamination is of high importance. Here we describe the design and application of DNA‐based fluorescent chemosensors on microbeads to differentiate eight toxic metal ions in water. We developed and synthesized four fluorescent 2′‐deoxyribosides of metal‐binding ligands. A tetramer‐length oligodeoxy‐fluoroside (ODF) library of 6561 members was constructed and screened for sequences responsive to metal ions, of which seven sequences were selected. Statistical analysis of the response patterns showed successful differentiation of the analytes at concentrations as low as 100 nM . Sensors were able to classify water samples from 13 varied sites and quantify metal contamination in unknown specimens. The results demonstrate the practical potential of bead‐based ODF chemosensors to analyze heavy metal contamination in water samples by a simple and inexpensive optical method.     

Enantiospecific electrodeposition of chiral CuO films on single-crystal Cu(111)

Epitaxial films of monoclinic CuO have been electrodeposited on single-crystal Cu(111) from solutions containing either (S,S)- or (R,R)-tartrate. X-ray pole figure analysis reveals that the CuO film grown from (S,S)-tartrate exhibits a (1) out-of-plane orientation while the film grown from (R,R)-tartrate has a (11) orientation. Even though CuO does not crystallize within a chiral space group, the orientations obtained exhibit a surface chirality similar to that obtained from high index fcc metal surfaces. The films were shown to be enantioselective toward the catalytic oxidation of tartrate molecules by cyclic voltammetry. The technique should prove to be applicable to the electrodeposition of chiral surfaces of other low-symmetry materials on achiral substrates and should prove to be of use to those interested in the synthesis, separation, and detection of chiral molecules.