反相高效液相法测定八角茴香果实中的莽草酸

用反相高效液相法在Waters Symmetry C18柱(5 μm,4.6 mm×150 mm i.d)上测定八角茴香果实中的莽草酸.工作参数为：流速0.5 mL/min;进样体积2 μL;检测波长220 nm;柱温30 ℃±1 ℃;流动相0.01 mol/L　K2HPO4磷酸盐缓冲液(pH值为3,用磷酸调配)和体积分数3%甲醇.平均回收率为97.76 %,RSD为1.937 %(n=5).     

Sodium β-Diketonate Glyme Adducts as Precursors for Fluoride Phases: Synthesis,Characterization and Functional Validation

Very few sodium complexes are available as precursors for the syntheses of sodium-based nanostructured materials. Herein, the diglyme, triglyme, and tetraglyme (CH₃O(CH₂CH₂O)_nCH₃, n = 2–4) adducts of sodium hexafluoroacetylacetonate were synthesized in a single-step reaction and characterized by IR spectroscopy, ¹H, and ¹³C NMR. Single-crystal X-ray diffraction studies provide evidence of the formation of the ionic oligomeric structure [Na₄(hfa)₆]²⁻•2[Na(diglyme₂]⁺ when the diglyme is coordinated, while a mononuclear seven-coordinated complex Na(hfa)•tetraglyme is formed with the tetraglyme. Reaction with the monoglyme (CH₃OCH₂CH₂OCH₃) does not occur, and the unadducted polymeric structure [Na(hfa)]_n forms, while the triglyme gives rise to a liquid adduct, Na(hfa)•triglyme•H₂O. Thermal analysis data reveal great potentialities for their applications as precursors in metalorganic chemical vapor deposition (MOCVD) and sol-gel processes. As a proof-of-concept, the Na(hfa)•tetraglyme adduct was successfully applied to both the low-pressure MOCVD and the sol-gel/spin-coating synthesis of NaF films.     

大气温度起伏谱的测量

用直径1μm和10μm金属丝分别测量了大气温度起伏功率谱,提出了测量湍流外尺度的方法。实测结果表明：在复杂的光传输路径上至少有50%的温度谱不符合Kolmogorov的－5/3定律;用直径1μm丝进行单点测量的C2n和直径10μm丝进行双点测量的C2n较为一致;80%的外尺度不超过7m。     

MOCVD 生长的动力学模式探讨

讨论金属有机化合物气相沉积(MOCVD)方式生长晶体的一种动力学解释．应用分子动力学、化学反应动力学等推导出MOCVD反应过程中晶体生长速度—原材料输运速度有关的公式,并应用这个公式进行了计算,计算结果与实际生长时的参数接近．     

TMIn流量对GaN基蓝光LED外延薄膜的影响

以蓝宝石(Al2O3)为衬底,采用有机金属化学气相沉积(MOCVD)技术生长InGaN/GaN多量子阱结构.本文通过调整外延生长过程中三甲基铟(TMIn)流量,研究了TMIn流量对InGaN/GaN多量子阱结构的合金组分、晶体质量和光学性质的影响.本文采用高分辨X射线衍射(HRXRD)、原子力显微镜(AFM)和光致发光(PL)测试表征其结构和光学性质.HRXRD测试结果表明,随TMIn流量增加,"0"级峰与GaN峰之间角偏离增大,更多的In并入薄膜中.HRXRD与AFM表征结果表明:增大TMIn流量会导致外延薄膜中的位错密度增大,V形坑数量增加,晶体质量严重恶化;PL测试结果表明,随着TMIn流量增加,发光强度逐渐降低,半高宽增大,这是由于晶体质量恶化所导致.因此严格控制铟源流量对于改善量子阱薄膜的晶体质量与光学性质有着至关重要的作用.     

Tin(II) aminoalkoxides and heterobimetallic derivatives: the structures of Sn6(O)4(dmae)4, Sn6(O)4(OEt)4 and [Sn(dmae)2Cd(acac)2]2

Tin(II) methoxide reacts with N,N′‐dimethylaminoethanol (dmaeH) to yield Sn(dmae)₂ ( 1 ) along with small amounts of the hydrolysis product Sn₆(O)₄(dmae)₄ ( 2 ). The geometrically more regular iso‐structural cage Sn₆(O)₄(OEt)₄ ( 3 ) was obtained as the only tractable product isolated from reaction of 2 and Sb(OEt)₃, while 1 reacted with CdX₂ (X = acac, I) to afford Sn(dmae)₂Cd(acac)₂ ( 4 ) and Sn(dmae)₂CdI₂ ( 5 ). The X‐ray structures of 2, 3 and 4 are reported. Decomposition of 4 under aerosol‐assisted chemical vapour deposition conditions leads to amorphous tin oxide films with no detectable cadmium (i.e. ca < 2% cadmium), rather than a stoichiometric Sn:Cd oxide. Copyright © 2006 John Wiley & Sons, Ltd.     

ECR放电中电子能量分布函数的确定

在ECR放电实验中，我们测量了简单镜中捕获的电子能量分布函数，通过测量双延迟势，可获得ECR放电中电子在磁镜装置镜喉区域的电子能量分布函数，利用光谱变分和朗缪尔探针可以确定电子分布函数的某些参数，放电是在氩气中进行的，实验中发现，不同的等离子体态有不同的分布函数，它们呈现出指数分布与幂分布。     

Zinc oxide quantum dots embedded films by metal organic chemical vapor deposition

Zinc oxide (ZnO) quantum dots (QDs) were fabricated on silicon substrates by metal organic chemical vapor deposition. Formation of QDs is due to the vigorous reaction of the precursors when a large amount of precursors was introduced during the growth. The size of the QDs ranged from 3 to 12 nm, which was estimated by high-resolution transmission electron microscopy. The photoluminescence measured at 80 K showed that the emission of QDs embedded film ranged from 3.0 to 3.6 eV. The broad near-band-edge emission was due to the quantum confinement effect of the QDs.     

Properties of ZnO films grown on (0 0 0 1) sapphire substrate using H2O and N2O as O precursors by atmospheric pressure MOCVD

In this paper, we compare the properties of ZnO thin films (0 0 0 1) sapphire substrate using diethylzinc (DEZn) as the Zn precursor and deionized water (H₂O) and nitrous oxide (N₂O) as the O precursors, respectively in the main ZnO layer growth by atmospheric pressure metal–organic chemical vapor deposition (AP-MOCVD) technique. Surface morphology studied by atomic force microscopy (AFM) showed that the N₂O-grown ZnO film had a hexagonal columnar structure with about 8 μm grain diameter and the relatively rougher surface compared to that of H₂O-grown ZnO film. The full-widths at half-maximum (FWHMs) of the (0 0 0 2) and () ω-rocking curves of the N₂O-grown ZnO film by double-crystal X-ray diffractometry (DCXRD) measurement were 260 and 350 arcsec, respectively, indicating the smaller mosaicity and lower dislocation density of the film compared to H₂O-grown ZnO film. Compared to H₂O-grown ZnO film, the free exciton A (FX_A) and its three phonon replicas could be clearly observed, the donor-bound exciton A⁰X (I₁₀):3.353 eV dominated the 10 K photoluminescence (PL) spectrum of N₂O-grown ZnO film and the hydrogen-related donor-bound exciton D⁰X (I₄):3.363 eV was disappeared. The electron mobility (80 cm²/V s) of N₂O-grown ZnO film has been significantly improved by room temperature Hall measurement compared to that of H₂O-grown ZnO film.     

Mass Transport of β-Diketonate Precursors for MOCVD of YBa_2Cu_3O_(7-δ) High T_c Superconducting Thin Films

IntroductionSoonafterthediscoveryofhighT.supercoducting(HTSC)oxides,metalor-ganicchemicalvapourdeposition(MOCVD)wasproposedforpreparingtheirthinfilms[1j.Asgenerallyacceptedtoday['J,thistechniquehasdemonstrateditssuperioradvantagesinmakinglargeareahighqualityHTSCthinfilmsandwillplayamajorroleintheadvanceofdeviceapplicationofHTSCthinfilmsoverthenextfewyears.TheprecursorsusedinMOCVDforpreparinghighT.superconductingthinfilmsaremostlymetalbeta-diketonates.Theyaresolidsatroomtemperatureand…