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151.
The conjecture of Tuinier (J. Colloid Interface Sci. 258 (2003) 45) for the electrical potentials near a cylindrical surface and near a spherical surface under the conditions of symmetric electrolyte and large scaled radius are derived by solving the corresponding Poisson-Boltzmann equation. The surface charge density-surface potential relations for these surfaces are also derived under the conditions of constant surface potential. We show that the level of surface charge density for planar, cylindrical, and spherical surfaces follows the order spherical surface > cylindrical surface > planar surface. 相似文献
152.
The structures of archaeal glycerophospholipids and glycolipids are unique in that they consist of phytanyl substituents ether linked to the glycerol backbone, imparting stability to the molecules. In this contribution, we described multiple-stage linear ion-trap combined with high resolution mass spectrometry toward structural characterization of this lipid family desorbed as lithiated adduct ions or as the [M−H]− and [M−2H]2− ions by ESI. MSn on various forms of the lithiated adduct ions yielded rich structurally informative ions leading to complete structure identification of this lipid family, including the location of the methyl branches of the phytanyl chain. By contrast, structural information deriving from MSn on the [M−H]− and [M−2H]2− ions is not complete. The fragmentation pathways in an ion-trap, including unusual internal loss of glycerol moiety and internal loss of hexose found for this lipid family were proposed. This mass spectrometric approach provides a simple tool to facilitate confident characterization of this unique lipid family. 相似文献
153.
Determination of Pd,Rh, Pt,Au in road dust by electrothermal vaporization inductively coupled plasma mass spectrometry with slurry sampling 总被引:1,自引:0,他引:1
Inductively coupled plasma mass spectrometry coupled with ultrasonic slurry sampling electrothermal vaporization (USS-ETV-ICP-MS) has been applied to determine Pd, Rh, Pt and Au in 0.5% m/v slurries of several road dust samples. 2% m/v ammonium pyrrolidine dithiocarbamate (APDC) was used as the modifier to enhance the ion count. The influence of instrument operating conditions, slurry preparation and interferences on the ion count was reported. This method has been applied to the determination of Pd, Rh, Pt and Au in BCR 723 Road Dust and NIST SRM 2709 San Joaquin Soil reference materials and two road dust samples collected locally. The analysis results of the standard reference materials agreed with the certified values. Precision between sample replicates was better than 10% for all the determinations. The method detection limits estimated from standard addition curves were 0.9, 0.4, 0.6 and 0.4 ng g−1 for Pd, Rh, Pt and Au, respectively, in original dust samples. 相似文献
154.
155.
Hui-Huang Chen Shih-Bin Lin Chieh-Ping Hsu Li-Chen Chen 《Cellulose (London, England)》2013,20(4):1967-1977
Bacterial cellulose (BC) is a nanoscale and useful biomaterial with a fine fiber network and high water holding capacity. However, dried BC exhibits poor rehydration ability. The present study investigated the rehydration ability of composites of hydrolyzed gelatin peptides (HGP) and hydroxypropylmethyl cellulose-modified BC (HBC). The HGP with molecular weights <9 kDa were obtained by hydrolyzing gelatin with a combination of 1 % alcalase and 1.5 % pronase E at 50 °C for 2 h. The HGP/HBC nanocomposites exhibited higher rehydration ratios than composites prepared with gelatin. According to SEM images, gelatin and HGP successfully penetrated the cellulose network in composite films prepared using both immersion and adsorption (DA) methods. The high hydrophilic property of HGP resulted in a rehydration ratio of approximately 180 % at a HGP/HBC ratio of 4.5:1 (W/W) in DA composites. The 1 min rehydrated HGP/HBC composites possessed similar mechanical properties to the original wet type composites. Overall, results indicated that the HGP/HBC composites prepared using the DA method demonstrated the highest rehydration ability among the composite films evaluated. 相似文献
156.
Ling-Yang Hsu Qiumin Liang Zhiheng Wang Hsin-Hung Kuo Wun-Shan Tai Shi-Jian Su Xiuwen Zhou Yi Yuan Yun Chi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(67):15375-15386
Iridium complexes bearing chelating cyclometalates are popular choices as dopant emitters in the fabrication of organic light-emitting diodes (OLEDs). In this contribution, we report a series of blue-emitting, bis-tridentate IrIII complexes bearing chelates with two fused five-six-membered metallacycles, which are in sharp contrast to the traditional designs of tridentate chelates that form the alternative, fused five-five metallacycles. Five IrIII complexes, Px-21 – 23 , Cz-4 , and Cz-5 , have been synthesized that contain a coordinated dicarbene pincer chelate incorporating a methylene spacer and a dianionic chromophoric chelate possessing either a phenoxy or carbazolyl appendage to tune the coordination arrangement. All these tridentate chelates afford peripheral ligand–metal–ligand bite angles of 166–170°, which are larger than the typical bite angle of 153–155° observed for their five-five-coordinated tridentate counterparts, thereby leading to reduced geometrical distortion in the octahedral frameworks. Photophysical measurements and TD-DFT studies verified the inherent transition characteristics that give rise to high emission efficiency, and photodegradation experiments confirmed the improved stability in comparison with the benchmark fac-[Ir(ppy)3] in degassed toluene at room temperature. Phosphorescent OLED devices were also fabricated, among which the carbazolyl-functionalized emitter Cz-5 exhibited the best performance among all the studied bis-tridentate phosphors, showing a maximum external quantum efficiency (EQEmax) of 18.7 % and CIEx,y coordinates of (0.145, 0.218), with a slightly reduced EQE of 13.7 % at 100 cd m−2 due to efficiency roll-off. 相似文献
157.
Yi-Hao Huang Chung-Cheng Chiang Yet-Pole I Chuen-Tzay Kuo Sheng-Hung Wu Jyh-Ping Hsu Jean-Claude Charpentier 《Journal of Thermal Analysis and Calorimetry》2013,114(3):1225-1229
This article covers the incompatible properties of nitric acid (HNO3) with formic acid (CH2O2), and more generally with various acids such as sulfuric acid (H2SO4), hydrochloric acid (HCl), and acetic acid (C2H4O2). Differential scanning calorimetry (DSC) was employed to determine the thermal hazard such as heat of decomposition (ΔH d), exothermic onset temperature (T 0), etc., in various acids. T 0 of HNO3 and CH2O2 were determined as 50 °C using DSC. Thus it has been observed that HNO3 mixed with CH2O2 should be prohibited during transportation, storage, and use. And more generally, process safety engineers and operator must take care to handle tanker and storage tank of typical acids in the transportation, storage, and manufacturing process. It is clear that there exists a need to follow and enforce in the chemical industries safety data sheets, globally harmonized system of classification and labeling of chemicals of United Nations (UN), education of safety and health, emergency response system, and process safety management. It is the aim of the present study concerning HNO3 with various acids. 相似文献
158.
Der‐Lii M. Tzou Lin‐Kai Ni Mei‐Man Chen Min‐Chuan Chiou Li‐Chou Chen Shan‐Te Hsu Kuo‐Lung Ku Chien‐Chung Cheng 《中国化学会会志》2013,60(9):1107-1112
Solid‐state Nuclear Magnetic Resonance (ss‐NMR) 13C single‐pulse excitation spectroscopy in combination with the magic‐angle spinning (MAS) technique was applied to a series of Phalaenopsis tissues, including the leaf, sheath, stem, and root, at different growth and spiking periods. Compared with{1H}/13C cross‐polarization MAS spectra, the 13C single‐pulse excitation MAS spectra displayed very distinct spectral patterns, recognizable as fingerprints of the tissues studied. 1Here, we demonstrate that solid‐state 13C single‐pulse excitation NMR spectroscopy provides a direct and robust analytical tool for studying the various tissues of Phalaenopsis in different growth and spiking induction periods. 相似文献
159.
Hsiu‐Fu Hsu Corresponding author Shih‐Jay Chien Hsiu‐Hui Chen Chien‐Hsing Chen Li‐Ya Huang Chung‐Hao Kuo 《Liquid crystals》2013,40(6):683-689
Liquid crystalline α,α′‐bis(4‐alkoxyphenylethynyl)oligothiophenes (bi‐ and ter‐thiophene) have been synthesized and their mesogenic behaviour and optical properties investigated. They all exhibited a nematic mesophase, and compounds with long alkoxy chains also showed lamellar phases. Increasing the number of thiophene units increased both the transition temperatures and the mesophase ranges. As for their optical properties, incorporating more thiophene units results in red‐shifted absorption and emission spectra, slightly enhanced quantum efficiency, and a larger Stoke's shift. Most importantly, in terms of the absorption and emission maxima, the incorporation of one 4‐alkoxyphenylethynyl moiety was found to be equivalent to adding one thiophene ring. 相似文献
160.