基于半像素错位的多幅图像重建高分辨率图像技术研究

介绍了一种基于半像素错位的多幅图像重建高分辨率图像技术。分析了半像素错位的多幅图像与高分辨率图像各像素灰度值的对应关系 ,并从CCD数字化采样的角度进行了论证。同时 ,结合实际摄像机CCD结构 ,求出了高分辨率图像重建的计算公式 ,并通过实验进行了验证和完善。重建的本质是以原高分辨率图像的 4邻域平均图像为基础 ,增加一定比例的边缘细节信息 ,去接近原高分辨率图像。CCD的动态范围越大 ,图像的灰度级越多 ,那么计算误差就越小 ,图像的边缘细节信息就可以利用更多 ,重建的图像就越接近原高分辨率图像。通过实验和分析表明 ,利用半像素错位的多幅低分辨率图像重建高分辨率图像的原理是正确的 ,方案是可行的     

流动注射在线阴离子树脂预富集火焰原子吸收测定痕量铜

研究了以阴离子交换树脂作吸附剂的流动注射在线微柱预富集火焰原子吸收测定铜的新方法。在最佳条件下富集１５０ｓ，富集２３倍，检出限０．２μｇ／Ｌ，ＲＳＤ为１．６％，分析速度２０次／ｈ。天然水样中可能存在的离子不干扰铜的测定。所建立的方法已用于水样中痕量铜的测定。     

流动注射在线共沉淀预富集火焰原子吸收法测定痕量铜

研究了以Ｎｉ＾２＋－ＤＤＴＣ为共沉淀载体，流动注射在线共沉淀预富集－火焰原子吸收光谱法测定痕量铜的体系，在０．３ｍｏｌ．Ｌ＾－１的硝酸介质中，铜离子在编织反应器中与Ｎｉ＾２＋－ＤＤＴＣ（产生共沉淀，并被收集在编织器内壁上，用甲基异丁基酮（ＭＩＢＫ）在线洗脱沉积物并引入火争原子化器中测定。当富集时间为４０ｓ时，４０μｇ．Ｌ＾－１的铜１０次测定的相对标准偏差为３．０％，灵敏度提高６０倍，检出限（３σ）     

Pt-Sn脱氢催化剂浸渍状态的Sn-119和Pt-195的多核NMR研究

测定了Ｐｔ－Ｓｎ型催化剂浸渍状态下的Ｓｎ－１１９、Ｐｔ－１９５的多核核磁共振。当ＳｎＣｌ２／ＤＣｌ溶液体系中加入Ｈ２ＰｔＣｌ６以后，出现了Ｓｎ（Ⅳ）和另外一种Ｓｎ（Ⅱ）的构型，Ｓｎ－１１９峰向高场位移，说明部分Ｓｎ（Ⅱ）被氧化成Ｓｎ（Ⅳ），Ｈ２ＰｔＣｌ６的量对这种氧化性影响较小。而Ｈ２ＰｔＣｌ６／Ｄ２Ｏ溶液体系中加入ＳｎＣｌ２以后部分Ｐｔ（Ⅳ）被还原成Ｐｔ（Ⅱ），随着ＳｎＣｌ２量的增加，Ｐｔ（Ⅱ）     

Elucidating dominant factors of PO43-, Cd2+ and nitrobenzene removal by biochar: A comparative investigation based on distinguishable biochars

Four distinct biochars were employed to remove three typical pollutants, meanwhile, path analysis, a multi-statistical regression method, was performed to elucidate the dominant factors of biochar adsorption. This work can provide a new insight to prepare a targeted biochar as adsorbents.     

二硫化钼基复合材料的合成及光催化降解与产氢特性

随着环境污染和能源短缺的加剧,无污染环境修复技术及清洁能源替代工程已成为一项重要而紧迫的任务。作为层状结构的过渡金属硫化物,二硫化钼带隙较窄,边缘具有高的反应活性,容易与其他物质形成复合结构,是近年来光催化环境修复及清洁能源领域的研究热点。本文详细介绍了半导体二硫化钼及其复合物的合成方法和光催化降解与产氢行为,重点阐述了二硫化钼及其复合物的具体复合方式、光催化降解污染物活性、光催化产氢活性以及具体的降解与产氢机理等方面的内容,并举例说明。二硫化钼及其复合物在光催化降解污染物和光催化产氢方面具有绿色、廉价、高效等优点,在环境修复及清洁能源领域具有巨大的潜力和应用发展前景。     

Liquid chromatographic analysis of nucleosides and their mono-, di- and triphosphates using porous graphitic carbon stationary phase coupled with electrospray mass spectrometry

Analysis of nucleosides and nucleotides is desirable in many biological studies, but the task is analytically challenging due to the high polarity of the analytes. In this study, resolution of mixtures containing nucleosides and their mono-, di- and triphosphates was achieved using a porous graphitic carbon (PGC) stationary phase, Hypercarb, under conditions suitable for liquid chromatography/mass spectrometry (LC/MS). Different organic mobile phases and modifiers were evaluated and the separation of 16 nucleosides and nucleotides was optimized using gradient elution with a water/acetonitrile mobile phase containing ammonium acetate and diethylamine as modifiers. The ammonium acetate concentration proved to be critical for retention and diethylamine was found to improve the peak shapes of di- and triphosphates for mass spectrometric detection. A variety of silica-based columns designed for polar compound separation were also tested using optimized LC conditions and compared with results obtained with the Hypercarb column. Only the Hypercarb column provided separations suitable for accurate quantitation of mixed nucleosides and their phosphates.     

Coupling of flow injection wetting-film extraction without segmentation and phase separation to flame atomic absorption spectrometry for the determination of trace copper in water samples

A flow injection wetting-film extraction system without segmentor and phase separator has been coupled to flame atomic absorption spectrometry for the determination of trace copper. Isobutyl methyl ketone (MIBK) was selected as coating solvent and 8-hydroxyquinoline (oxine) as the chelating reagent. By switching of a 8-channel valve and alternative initiation of two peristaltic pumps, MIBK, sample solution containing copper chelate of oxine, and air-segment sandwiched eluting solution (1.0 mol l⁻¹ nitric acid) were sequentially aspirated into an extraction coil made of PTFE tubing of 360 cm length and 0.5 mm i.d. The formation of organic film in the wall of the extraction coil, extraction of the copper chelate into the organic film and back-extraction of the analyte into the eluting solution occurred consecutively when these zones aspirated into the extraction coil were propelled down the extraction coil by a carrier solution at a flow rate of 2 ml min⁻¹. After leaving the extraction coil, the concentrated zone was transported to the nebulizer at its free uptake rate for atomization. Under the optimized conditions, an enrichment factor of 43 and a detection limit of 0.2 μg l⁻¹ copper were achieved at a sample throughput rate of 30 h⁻¹. Eleven determinations of a standard copper solution of 60 μg l⁻¹ gave a relative standard deviation of 1.5%. Foreign ions possibly present in tap water and natural water did not interfere with the copper determination. The developed method has been successfully used to the determination of copper content of tap water and river water.     

Room-temperature multiferroic properties of Co-doped KNbO3 ceramics

KNb_0.95Co_0.05O₃ (KN–Co) ceramic was prepared via a solid-state reaction method, and the effect of cobalt dopant on the structural, electric, and magnetic properties was studied. The KN–Co ceramic with polycrystalline perovskite structure exhibited ferromagnetic and ferroelectric properties simultaneously at room temperature, and the coupling of them was confirmed by a large magnetocapacitance effect (about 13%) near the Curie temperature. The possible causes for the magnetism and magnetoelectric properties are discussed.