用MOCVD法在YSZ衬底上制备YBCO膜

用低压ＭＯＣＶＤ多源法在单晶ＹＳＺ和具有双轴取向ＩＢＡＤＹＳＺ的金属基带上沉积了ＹＢＣＯ膜,它们的Ｊｃ（７７．３Ｋ,０Ｔ）分别为～２×１０６Ａ／ｃｍ２和～７×１０４Ａ／ｃｍ２．分析了本试验中的Ｊｃ差别原因．在单晶ＹＳＺ上ＹＢＣＯ高Ｊｃ数值显示了用ＭＯＣＶＤ制备涂层膜导体的潜力     

Ba,Sr,Ca在Co／γ—Al2O3催化剂上CO氧化的作用机制（II）

用硝酸盐水溶液等量共浸法制备了分别在７５０℃和９００℃焙烧的系列催化剂Ｃｏ－Ｍ／γ－Ａｌ２Ｏ３（Ｍ＝Ｃａ，Ｓｒ，Ｂａ，Ｃｏ３Ｏ４／Ａｌ２Ｏ３＝８ｗｔ％，Ｍ／Ｃｏ＝１５ｍｏｌ％）测定了ＣＯ氧化转化率，用ＢＥＴ表面，ＸＲＤ，ＸＰＳ，ＤＴＡ和ＴＰＲ等手段研究了助剂Ｂａ，Ｓｒ，Ｃａ的作用，结果表明，加入助剂后，ＣＯ完全转化温度下降了２０～６０℃左右，助剂的作用顺序为Ｃａ＞Ｓｒ＞Ｂａ，实验表明，７５０℃和９     

MOCVD法在金属基体上制备YBCO超导带

本报道了用ＭＯＣＶＤ静态和动态沉积两种工艺制备ＹＢＣＯ超导带的实验结果。以Ｙ（ＴＭＨＤ）３、Ｂａ（ＴＭＨＤ）２和Ｃｕ（ＴＭＨＤ）２为挥发源，Ｏ２气为反应剂，高纯Ａｒ气为载流气体，在静止和以１０－１５ｃｍ／ｈ带速移动的金属银基体上，制出了有强烈ｃ－轴取向的ＹＢＣＯ超导带。静态沉积样品的Ｊｃ达到１．０４×１０＾４Ａ／ｃｍ＾２，动态沉积样品的Ｊｃ达到１．４×１０＾４Ａ／ｃｍ＾２（７８Ｋ，０Ｔ）。对改…     

GIANT MAGNETO-IMPEDANCE IN Fe-BASED SOFT FERROMAGNETIC RIBBONS

ＧＩＡＮＴＭＡＧＮＥＴＯ－ＩＭＰＥＤＡＮＣＥＩＮＦｅ－ＢＡＳＥＤＳＯＦＴＦＥＲＲＯＭＡＧＮＥＴＩＣＲＩＢＢＯＮＳＣｈｅｎＣｈｅｎＭｅｉＬｉａｎｇｍｏＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，ＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉｔｙ，Ｊｉｎａｎ２５０１００...     

环糊精—表面活性剂包结作用的研究

应用表面张力方法研究了β－环糊精（β－ＣＤ）对十二烷基苯磺酸钠（ＳＤＢＳ）的包结作用，研究了不同温度下β－ＣＤ对ＳＤＢＳ表面活性的影响以及脂肪醇加入β－ＣＤ包结ＳＤＢＳ表面活性的影响，求得了不同温度下β－ＣＤ包结ＳＤＢＳ的平衡常数Ｋ，并用＾１ＨＮＭＲ波谱探讨了包结物β－ＣＤ／ＳＤＢＳ的分子结构模型。     

火焰原子吸收光谱法直接测定蜂蜜制品中锌

本文研究了阴离子表面活性剂十二烷基磺酸钠（ＳＤＳ），阳离子表面活性剂十六烷基三甲基溴化铵（ＣＴＭＡＢ），非离子表面活性ＴｒｉｔｏｎＸ－１００，Ｔｗｅｅｎ－２０，Ｔｗｅｅｎ－８０及铬天菁Ｓ（ＣＡＳ），邻菲罗啉（Ｐｈｅｎ），８－羟基喹啉（Ｏｘｉｎｅ），盐酸羟胺，二乙基二硫代氨基甲酸钠（ＤＤＴＣ）等数种试对锌的增敏作用，初探了其增敏机理和抑制干扰的机理，选用了增敏作用最强的Ｔｒｉｔｏｎ－Ｘ－１００增敏剂     

单源溶液超声波雾化MOCVD法在Ag基体上制备YBCO膜

本报道了用单溶液超声波雾化ＭＯＣＶＤ工艺在金属Ａｇ基体上制备了ＹＢＣＯ超导膜的结果。将Ｙ（ＴＭＨＤ）３、Ｂａ（ＴＭＨＤ）２和Ｃｕ（ＴＭＨＤ）２按要求比例溶于四氢呋喃中，经超声波雾化，通过毛细管送入蒸发室，随即进入沉积室，在Ａｇ基体上沉积ＹＢＣＯ。该技术有效地简化了ＣＶＤ过程，提高了所制样品的再现性。ＸＲＤ分析表明，ＹＢＣＯ膜具有较好的ｃ－轴取和向单相性。     

MBE和MOCVD生长的AlGaAs／GaAsGRIN—SCH SQW激光器深中心的比较

应用深能级瞬态谱（ＤＬＴＳ）技术详细研究分子束外延（ＭＢＥ）和金属有机物化学汽相淀积（ＭＯＣＶＤ）生长的ＡｌＧａＡｓ／ＧａＡｓ ｇｒａｄｅｄ ｉｎｄｅｘ ｓｅｐａｒａｔｅ ｃｏｎｆｉｎｅｍｅｎｔ ｈｅｔｅｒｏｓｔｒｕｃｔｕｒｅ ｓｉｎｇｌｅ ｑｕａｎｔｕｍ ｗｅｌｌ（ＧＲＩＮ－ＳＣＨ ＳＱＷ）激光器的深中心。结果表明，在激光器的ｎ－ＡｌＧａＡｓ层里除众所周知的ＤＸ中心外，还存在着较大浓度和俘获截面     

YBCO/CeO_2/LaAlO_3夹层膜的界面研究

用俄歇电子能谱（ＡＥＳ）结合透射电子显微镜（ＴＥＭ）对磁控溅射法制备的ＹＢＣＯ／ＣｅＯ２／ＬａＡｌＯ３夹层膜中的元素在各层间的扩散行为进行了研究．结果表明，ＣｅＯ２作为一种缓冲层，能够阻挡住基底ＬａＡｌＯ３中元素向ＹＢＣＯ膜的扩散和ＹＢＣＯ膜中元素向基底的扩散，其本身向ＹＢＣＯ膜中的扩散也不多．ＴＥＭ的分析表明，ＣｅＯ２能保持完好的晶格结构，在其上能得到结构完整的高质量ＹＢＣＯ膜     

TBP对部分皂化的DMHPA—正庚烷体系及萃取稀土有机相的影响

研究了部分皂化的二（１甲基庚基）磷酸（ＤＭＨＰＡ）磷酸三丁酯（ＴＢＰ）—正庚烷（Ｃ７Ｈ１６）体系及萃取稀土有机相的聚集状态。结果表明，ＴＢＰ可以扩大ＤＭＨＰＡＣ７Ｈ１６Ｈ２Ｏ微乳状液形成的区间，并且对萃取有机相的存在状态及水的行为有明显的影响，在一定的条件下有凝胶形成。ＦＴＩＲ光谱分析表明，该类凝胶中ＤＭＨＰＡ和ＴＢＰ与稀土离子以多种形式配位，ＴＢＰ与ＤＭＨＰＡ及水的氢键结合对凝胶网状结构的形成也起了一定的作用。     

Engineered doped and codoped polyaniline gas sensors synthesized in N,N,dimethylformamide media

Conducting Polyaniline films (Pani) on Corning glass substrates, produced using either an in-situ doping process or a co-doping process, were prepared by the oxidative polymerization of aniline in N,N,dimethylformamide. Bicyclic aliphatic camphorsulfonic acid (CSA), aromatic toluenesulfonic acid (TSA) and carboxylic trifluoroacetic acid (TFA) were employed as doping agents, and CSA mixed with TSA and CSA mixed with TFA were employed as the co-doping materials. The topography of the Pani films was analyzed by atomic-force microscopy (AFM), and their doping and oxidizing states were characterized by Fourier-transform infrared (FT-IR) spectroscopy and optical (UV-Vis) spectroscopy. Flower-like clusters, microfibers, and nanofibers were obtained by doping with CSA, TSA, and the mix of both (CSATSA), respectively. The flower-like morphology limits the conductivity of the film while the microfiber morphology leads to a highly conductive film. The conductivity of the films increases with the doping level, coil-like conformation of the chain and the protonation of the imine in quinoid units. The codoped process reduces the roughness of the CSA-doped films by 50%, but the conductivity depends on the acid type used for this process (TSA or TFA). The optical gas sensor response of the films is related to both the morphology and the degree of protonation. In this study, Pani with a microfiber morphology obtained from TSA-doping is the most sensitive to ammonia gas sensing, and Pani with flower-like morphology is the least sensitive.     

One-dimensional optical reflectors based on self-organization of polymeric comb-shaped supramolecules

We demonstrate that complexation of dodecylbenzenesulphonic acid, DBSA, to a diblock copolymer of polystyrene- block-poly(4-vinylpyridine), PS- block-P4VP, leads to polymeric supramolecules PS- block-P4VP(DBSA)y (y = 1.0, 1.5, and 2.0), which self-organize with a particularly large lamellar periodicity in excess of 1000 A. The structures consist of alternating PS and P4VP(DBSA)y layers, where the latter contains smaller internal structure, probably lamellar. The DBSA side chains are bonded to the pyridines by protonation and hydrogen bonding and they effectively plasticize the material. In this way relatively well-developed structures are obtained even without annealing or macroscopic alignment. Transmission and reflectance measurements show that a relatively narrow and incomplete bandgap exists for supramolecules of high molecular weight block copolymer at ca. 460 nm.     

Role of mesoscopic morphology in charge transport of doped polyaniline

In doped polyaniline (PANI), the charge transport properties are determined by mesoscopic morphology, which in turn is controlled by the molecular recognition interactions among polymer chain, dopant and solvent, Molecular recognition plays a significant role in chain conformation and charge delocalization. The resistivity of PANI doped by camphor sulfonic acid (CSA)/2-acrylo-amido-1-propane sulfonic acid (AMPSA)/dodecyl benzene sulfonic acid (DBSA) is around 0.02 Ω cm. PANI-CSA and PANI-AMPSA show a metallic positive temperature coefficient of resistivity above 150 K. with a finite value of conductivity at 1.4 K; whereas, PANI-DBSA shows hopping transport at low temperatures. The magnetoresistance is positive (negative) for PANI-CSA (PANI-AMPSA); and PANI-DBSA has a large positive MR. The behavior of MR suggests subtle variations in mesoscopic morphology between PANI-CSA and PANI-AMPSA.     

Structure/Property Relationships for Poly(Vinylidene Fluoride)/Doped Polyaniline Blends

Poly(vinylidene fluoride) (PVDF) and its blends with polyaniline (PANI) doped with dodecylbenzene sulfonic acid (DBSA) were characterized by electrical conductivity, differential scanning calorimetry (DSC) and X‐ray scattering techniques.

The onset of an infinite cluster (InC) of conducting, highly anisometric PANI/DBSA particles in PVDF/(PANI/DBSA) blends was observed at the percolation threshold as low as w*≈3.5 wt.%. The small angle X‐ray scattering (SAXS) data confirmed the expected spatial organization of PANI/DBSA needles into fractal‐like structures above w*. A slight decrease of both the DSC and the wide‐angle X‐ray scattering (WAXS) degrees of crystallinity of PVDF with the PANI/DBSA mass content w was explained by strong interactions at the PVDF/(PANI/DBSA) interface resulting in the loss of crystallizability of a fraction of sterically immobilized chains of PVDF in boundary layers around PANI/DBSA particles. The available data suggest that the conductive paths within InC of PANI/DBSA in PVDF/(PANI/DBSA) blends were formed primarily by the end‐to‐end contacts of PANI/DBSA fibrils.     

Thermal,surface, nanomechanical and electrical properties of epoxidized natural rubber (ENR-50)/ polyaniline composite films

A new composite material from epoxidized natural rubber (ENR-50) and polyaniline have been successfully prepared. Aniline which was polymerized in the presence of dodecylbenzene sulfonic acid (DBSA), then added to ENR-50 for the preparations of ENR-50/Pani.DBSA composite films. The hydrogen bonding which contribute to the formation of ENR-50/Pani.DBSA composites was observed in FT–IR, UV–Visible and DSC. It showed hydrogen bonding interactions between the epoxy groups in ENR-50 and the amine groups in Pani.DBSA. The morphologies of the prepared materials were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM and conductivity measurements revealed that the percolation threshold is at 2.5 w% of Pani.DBSA content. Atomic force microscopy (AFM) micrographs showed that ENR-50 with 5 wt% Pani.DBSA addition has the lowest surface roughness. In addition thermogravimetric analysis indicates improved thermal stability at low Pani.DBSA content. DSC measurements revealed that T_g value increases with increasing Pani.DBSA, indicating that the formation of homogenous composite material. Nanoindentation results show that the hardness (H) and Young's modulus (E_s) increased with higher addition of Pani.DBSA polymer.     

硫代水杨酸在银表面的化学吸附及其表面增强拉曼光谱研究

采用电化学法对Ag电极粗糙活化,进而对含巯基基团的硫代水杨酸(TSA)进行表面增强拉曼光谱(SERS)研究。研究表明,溶液浓度与pH对增强效应影响显著,1×10-3 mol·L-1与pH 4分别为增强效应的最佳浓度与酸度。浓度增大由于空间位阻等因素影响而增强效应急速下降。由TSA化学吸附所产生的S—Ag峰位基本不随pH改变;但pH对峰强度有显著影响。经对TSA在不同pH下的分布和机理研究表明,TSA是通过中性C₆H₄(COOH)SH分子中的硫醇端基脱H后与活化的Ag表面进行吸附,形成S—Ag化学键而产生SERS光谱。在较强碱性条件下负一价的C₆H₄(COO-)SH 可能与OH- 形成竞争吸附而不易产生SERS;同时吸附基团巯基对羧基振动谱峰的变化以及对苯环共轭体系中的电子云分布有很大影响。     

Properties of mesoporous tungstosilicic acid/titania composites prepared by sol-gel method

The tungstosilicic acid/titania composites were prepared by the sol-gel method. Titanium isopropoxide was used as titania precursor, and urea as a low-cost template. The tungstosilicic acid (TSA) was added in the same step as that in which titania hydrogel is formed. The TSA-modified samples only showed the characteristic peaks of anatase phase of titanium oxide in the XRD patterns, indicating that the presence of TSA retarded the crystallization of the anatase phase and its transformation into the rutile phase. Spherical particles with sizes between 200 and 700 nm, formed by aggregation of nanoparticle aggregates (4-50 nm in size), were observed. The particle size increased when the TSA content was raised and also increased slightly with the thermal treatment temperature. Mesoporous materials were obtained, with a mean pore diameter higher than 3.1 nm. Both the increase of the TSA concentration in the solid and the calcination temperature led to a decrease in the specific surface area of the samples. The main heteropolyoxometallate species present in the composites is the [SiW₁₂O₄₀]⁴⁻ anion for the composites calcined up to 500 °C. The band gap energy decreased as a result of the introduction of TSA into the titania matrix, though it remained almost constant with the calcination temperature increase.     

Four-element division algorithm to focus coherent light through a turbid medium

Aiming to overcome the low converging rate and susceptibility to the environment in focusing the coherent light through the turbid medium, four-element division algorithm(FEDA) optimization is proposed. Full levels of comparisons with the currently employed element-based algorithms, stepwise sequential algorithm(SSA), and continuous sequential algorithm(CSA) show that FEDA only takes one third of the measurement time to find the optimized solution, which means that FEDA is promising in practical applications, such as for deep tissue imaging.     

Synthesis of 2-(1,5-diaryl-1,4-pentadien-3-ylidene)-hydrazinecarboximidamide hydrochloride catalyzed by p-dodecylbenzenesulfonic acid in aqueous media under ultrasound irradiation

Amidinohydrazone compounds are very important synthetic intermediates and can serve as versatile precursors in synthesis of many natural products and drug molecules. The use of ultrasound, p-dodecylbenzenesulfonic acid (DBSA) and water as solvent improved the synthesis of different 2-(1,5-diaryl-1,4-pentadien-3-ylidene)-hydrazinecarboximidamide hydrochlorides. The best reaction conditions for the condensation of 1,5-diphenyl-1,4-pentadien-3-one with aminoguanidine hydrochloride were as follows: 1,5-diphenyl-1,4-pentadiene-3-one (1, 1 mmol), aminoguanidine hydrochloride (1.1 mmol), DBSA (0.5 mmol), water 10 mL, reaction temperature 25-27°C, irradiation frequency 25 kHz. 2a was achieved in 94% yield within 2h. The other seven amidinohydrazones were obtained in 84-94% yield within 2-3h under the same conditions. Compared to the method involving catalysis by hydrochloric acid in refluxing EtOH, the advantages of present procedure are milder conditions, shorter reaction times, higher yields, and environmental friendly conditions, which make it a useful strategy for the synthesis of analogues.     

Polypyrrole–montmorillonite nanocomposites synthesized by emulsion polymerization

The structural, electrical, magnetic, and thermal properties were investigated for the nanocomposites of polypyrrole (PPy) and inorganic clay (Na⁺-montmorillonite) prepared by emulsion polymerization. Dodecylbenzenesulfonic acid (DBSA) was used as emulsifier (surfactant) and dopant. The X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images showed that the conducting PPy was intercalated into the clay layers in nanoscale (<10 Å). The dc conductivity (σ_dc) of PPy–DBSA with clay was 6 S/cm, while that of PPy–DBSA without clay was 20 S/cm at room temperature (RT). Temperature dependence of σ_dc of both samples followed the three dimensional variable range hopping (VRH) model. From the g-value and the temperature dependence of EPR linewidth, paramagnetic signals were strongly affected by the partially negatively charged clay layers. The thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) showed that the clay induced the thermal stability of the systems.