Surface relief resonant Brewster niters with multiple channels

In this paper, a new type of resonant Brewster filters (RBF) with surface relief structure for the multiple channels is first presented by using the rigorous coupled-wave analysis and the S-matrix method. By tuning the depth of homogeneous layer which is under the surface relief structure, the multiple channels phenomenon is obtained. Long range, extremely low sidebands and multiple channels are found when the RBF with surface relief structure is illuminated with Transverse Magnetic incident polarization light near the Brewster angle calculated with the effective media theory of sub wavelength grating. Moreover, the wavelengths of RBF with surface relief structure can be easily shifted by changing the depth of homogeneous layer while its optical properties such as low sideband reflection and narrow band are not spoiled when the depth is changed. Furthermore, the variation of the grating thickness does not effectively change the resonant wavelength of RBF, but have a remarkable effect on its line width, which is very useful for designing such filters with different line widths at desired wavelength.

Determination of phthalate acid esters plasticizers in plastic by ultrasonic solvent extraction combined with solid-phase microextraction using calix[4]arene fiber

Ultrasonic solvent extraction combined with solid-phase microextraction (SPME) with calix[4]arene/hydroxy-terminated silicone (C[4]/OHTSO) oil coated fiber was used to extract phthalate acid esters (PAEs) plasticizers in plastic, such as blood bags, transfusion tubing, food packaging bag, and mineral water bottle for analysis by gas chromatography (GC). Both extraction parameters (i.e. extraction time, extraction temperature, ionic strength) and conditions of the thermal desorption in a GC injector were optimized by analysis of eight phthalates. The fiber shows wonderful sensitivity and selectivity to the tested compounds. Owing to its high thermal stability (380 degreesC), the carryover effect that often encountered when using conventional fibers can be reduced by appropriately enhancing the injector temperature. The method showed linear response over two to four orders of magnitude with correlation coefficients (r) better than 0.996, and limits of detection (LOD) ranged between 0.006 and 0.084 mug l(-1). The relative standard deviation values obtained were less than or equal to 10%. bis-2-Ethylhexyl phthalate (DEHP) was the sole analyte detected in these plastics and recoveries were in the ranges 95.5-101.4% in all the samples. (C) 2004 Elsevier B.V. All rights reserved.

Structural and optical characterization of InAs nanostructures grown on high-index InP substrates

The structural and optical properties of InAs layers grown on high-index InP surfaces by molecular beam epitaxy are investigated in order to understand the self-organization of quantum dots and quantum wires on novel index surfaces. Four different InP substrate orientations have been examined, namely, (1 1 1)B, (3 1 1)A, and (3 1 1)B and (1 0 0). A rich variety of InAs nanostructures is formed on the surfaces. Quantum wire-like morphology is observed on the (1 0 0) surface, and evident island formation is found on (1 1 1)A and (3 1 1)B by atomic force microscopy. The photoluminescence spectra of InP (1 1 1)A and (3 1 1)B samples show typical QD features with PL peaks in the wavelength range 1.3-1.55 mu m with comparable efficiency. These results suggest that the high-index substrates are promising candidates for production of high-quality self-organized QD materials for device applications. (C) 1999 Elsevier Science B.V. All rights reserved.

基于RS和GIS的县域土地利用变化特征分析

基于RS和GIS技术,结合土地利用变化指数模型定量分析了江西省新建县1991—2000年(分两个时段)的土地利用变化时空特征。结果表明,研究期间耕地面积减少2199.181hm2,林地面积增加1655.375hm2,建设用地面积增加1880.467hm2,未利用地减少1290.016hm2,草地和水域面积变化不大。6种土地利用类型中建设用地变化动态度最大,其次为未利用地,再次为林地和耕地,且研究区1991—2000年区域综合土地利用动态度为0.165%。土地利用程度综合指数1991年、1996年、2000年分别为243.687、244.084、244.868,呈上升趋势。土地利用空间动态度仍以建设用地为最大,其次为未利用地和草地,耕地最小。同时,研究得出了各土地利用类型在研究时段的“涨势”或“落势”状态。新建县1996—2000年区域土地利用变化空间动态度比1991—1996年有所下降,且土地利用变化逐渐由双向转移向单向不平衡转移转化。

Investigation of sandwiched gadolinium(III) complexes with tungstosilicates as potential MRI contrast agents

Two gadolinium-sandwiched complexes with tungstosilicates, K-13[Gd(SiW11O39)(2)] (Gd(SiW11)(2)) and K11H6[Gd2O3(SiW9O34)(2)] (Gd-3(SiW9)(2)), have been investigated by in vitro and in vivo experiments as potential contrast agents for magnetic resonance imaging (MRI). T-1-relaxivity of Gd(SiW11)(2)was 6.59 mM(-1) . s(-1) in aqueous solution and 6.85 mM(-1) . s(-1) in 0.725 mmol . L-1 bovine serum albumin solution at 25degreesC and 9.39 T, respectively. The corresponding T-1-relaxivity of Gd-3(SiW9)(2) was 12.6 and 19.3 mM(-1) . s(-1) per Gd, respectively. MRI for Sprague-Dawley rats showed longer and more remarkable enhancement in rat liver after i.v. injection of these two complexes: 39.4 +/- 3.9% and 57.4 +/- 11.6% within the first 30 min after injection, 31.2 +/- 2.6% and 39.9 +/- 7.6% in the next 60 min for Gd(SiW11)(2) and Gd-3(SiW9)(2) at doses of 0.081 and 0.084 mmol Gd/kg, respectively. Our preliminary in vitro and in vivo study indicates that Gd(SiW11)(2) and Gd-3(SiW9)(2) are favorable candidates for hepatic contrast agents for MRI. However, the two complexes exhibit higher acute toxicity and need to be modified and studied further before clinical use.

近红外光谱法快速测定多组分混合物中乳糖和玉米淀粉的含量

采用近红外光谱法测量了由对乙酰氨基苯酚、乙水杨胺、乳糖、玉米淀粉四种材料混合粉末的50个样品中乳糖和淀粉的含量,并由布奇NIRCalV4.21软件计算得到定量分析模型.发现对于乳糖,校正集和验证集的标准偏差分别为0.203和0.213.对于淀粉而言,校正集和验证集的标准偏差分别为0.084和0.081.表明利用近红外光谱建立的模型可以快速准确预测混合物中淀粉和乳糖的含量.

A two-dimensional molybdenum (V) phosphate with covalently bonded transition metal coordination complexes: hydrothermal synthesis and structure characterization of Na-2[{Mn(phen)(2)(H2O)}{Mn(phen)(2)}(3){Mn (Mo12O24)-O-V (HPO4)(6)(PO4)(2)(OH)(6)}] center dot 4H(2)O (phen=1,10-phenanthroline)

An organic-inorganic hybrid molybdenum phosphate, Na-2[{Mn(phen)(2)(H2O)} {Mn(phen)(2)}(3){(MnMo12O24)-O-v (HPO4)(6)(PO4)(2) (OH)(6)}] . 4H(2)O (phen=1,10-phenanthroline), involving molybdenum present in V oxidation state and covalently bonded transition metal coordination complexes, has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Deep brown-red crystals are formed in the triclinic system, space group P (1) over bar, a=16.581(l)Angstrom, b=18.354(1)Angstrom, c=24.485(2)Angstrom, alpha=80.589(l)degrees, beta=71.279(1)degrees, gamma=67.084(1)degrees, V=6493.8(8)Angstrom(3), Z=2, lambda(MoKalpha)=0.71073Angstrom (R(F)=0.0686 for 29,053 reflections). Data were collected on a Bruker Smart Apex CCD diffractometer at 293 K in the range of 1.76 < theta < 28.06degrees using omega-2theta scans technique. The structure of the title compound may be considered to be based on {Mo6O12(HPO4)(3)(PO4)(OH)(3)} units bonded together with {Mn(phen)(2)} subunits into a two-dimensional network. Two types of tunnels are observed in the solid of the title compound.

Studies on the interaction of porphyrin with antibody with fluorescent spectrum and UV-Vis differential spectra

After meso-tetra (alpha, alpha, alpha, alpha-O-phenylacetyl benzene)porphyrin combined with McAb 1F2, there was a significant hyperchromic effect, indicating that the combination of porphyrin and antibody is rigid and compact, aromatic amino acids exist at the combining sites of antigen in antibody. These aromatic amino acids are Trys and Trps, but the numbers of Trp are more than that found for Trys. The stochiometric ratio of porphyrin to 1F2 is 1:1, the disassociation constant was determined as(2.084+/-0.216) x 10(-10) mol/L by a method of fluorescence quenching, showing that both have a high affinity.

SYNTHESIS, THERMAL-STABILITY AND X-RAY CRYSTAL-STRUCTURE OF THE BIS(CYCLOPENTADIENYL)YTTERBIUM NAPHTHOXIDE DERIVATIVE (C5H5)2YB(OC10H7)(THF)

Cp3Yb (Cp = C5H5) reacts with a-naphthol (HNP) in THF to form Cp2Yb(NP)(THF) (1), which crystallizes in the space group P2(1)/n with unit cell dimensions a = 8.084(2), b = 15.996(6), c = 15.973(7) angstrom, beta = 98.95(3), V = 2040.3 angstrom and D(calc.) = 1.69 g cm-3 for Z = 4. Least-squares refinement based on 2242 observed reflections converged to a final R value of 0.081. The average Yb-C(Cp) distance is 2.60(2) angstrom and Yb-O(THF) and Yb-O(NP) distances are 2.30(1) and 2.06(1) angstrom, respectively. The title compound loses the coordinated THF molecule readily by heating under vacuum to give dimeric [Cp2Yb(NP)]2 (2), which undergoes disproportionation to give Cp3Yb and Yb(NP)3 on heating above 230-degrees-C.

渤海湾和胶州湾表层沉积物中甾醇的分布和来源

甾醇及其成岩作用过程中生成的衍生物普遍存在于沉积物中，由于该类化合物的特定来源及其分子结构中的不同特征结构反应了在不同生物体体内合成过程的差异，因此常将其作为一类重要的生物化学标志物用于指示与许多海洋及陆 地生物有关的有机物质的来源和输入，以及用于生物地球化学的研究和环境质量及环境污染的评价。该类化合物在近海环境中已得到广泛应用，然而对中国北部陆海相互作用强烈，受人类活动影响显著的近海沉积物中甾醇的研究尚未见报道。 本研究以渤海湾和胶州湾为目标，系统研究了甾醇类化合物在渤海湾和胶州湾22 个表层沉积物样品中含量和组成，并分析了其分布特征和来源。 通过测定沉积物有机物C/N 比值，表明渤海湾和胶州湾 两海区沉积物中的有机物主要来自陆源植物和人为源的输入。所测定的8 种甾醇类化合物在两海区表层沉积物中的含量和分布具有很大的区域差异，其浓度范围在0~4.303 μg/g，渤海湾甾醇总浓度为0.287~18.579 μg/g，高于胶州湾0.084~10.584 μg/g。8种化合物中只有谷甾醇在全部样品中检出，而粪便甾醇仅存在于受人类活动影响较大和有生活污水输入的近岸区域。而代表陆源高等植物来源的特征甾醇化合物豆甾醇和谷甾醇则在河口区表层沉积物中分布较高。研究表明根据表层沉积物中不同甾醇化合物的组成、含量和分布特征，可以很好地指示河流输入以及大量生活废水的排放对近岸海区的污染状况, 从而可以作为近岸环境污染监测和评价的重要指标。