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1.
Hui-Ling Li De-Jiang Qi Qing-Quan Jiang Shu-Zheng Yang 《International Journal of Theoretical Physics》2006,45(12):2428-2436
An extension of the Parikh-Wilczek's semi-classical quantum tunneling method, the tunneling radiation of the charged particle from a torus-like black hole is investigated. Difference from the uncharged mass-less particle, the geodesics of the charged massive particle tunneling from the black hole is not light-like, but determined by the phase velocity. The derived result shows that the tunneling rate depends on the emitted particle's energy and electric charge, and takes the same functional form as uncharged particle. It proves also that the exact emission spectrum is not strictly pure thermal, but is consistent with the underlying unitary theory.
PACS Numbers: 04.70.Dy, 97.60.Lf, 05.30.Ch. 相似文献
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Microchip capillary electrophoresis (μCE) with amperometric detection at Cu electrode benefited fast separation and direct detection of carbohydrates. The working electrode of 50-μm Cu wire attached nearly against the channel outlet—4 μm, where it benefited collecting detection current and suppressing overwhelming noise. The use of alkaline medium was essential to separating and detecting carbohydrates, which dissociated into the sensitive alcolate anions. The 10-cm serpentine chip, though lengthening the migration time, it provided better efficiency. Sucrose, cellobiose, glucose, and fructose migrated from the outlet in 400 s +2000 V. The linear calibration plots ranging from 10 to 1000 μM with regression coefficients better than 0.996 were obtained. The injection-to-injection reproducibility of 1.24% (n=7) for glucose in peak current and 0.6% for migration times were excellent. The detection limit was low, down to 2.3 μM for glucose (S/N=3) or 27.6 attomole in mass detection. 相似文献
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Yen YS Lin YC Huang SL Liu YH Sung HL Wang Y 《Journal of the American Chemical Society》2005,127(51):18037-18045
The cationic complex {[Ru]=C=CHCPh2CH2CH=CH2}BF4 (3a, [Ru] = (eta5-C5H5)(PPh3)2Ru) in solution transforms to {[Ru]=C=CHCH2CPh2CH=CH2}BF4 (4a) via a new metathesis process of the terminal vinyl group with the C=C of the vinylidene group which is confirmed by 13C labeling studies. This transformation is irreversible as revealed by deuteration and decomplexation studies. The cationic complex {[Ru]=C=CHCPh2CH2CMe=CH2}BF4 (3b) undergoes a cyclization process yielding 6b containing a eta2-cyclic allene ligand which is fully characterized by single-crystal X-ray diffraction analysis. Analogous complexes 4a' and 6b' ([Ru] = (eta5-C5H5)(dppe)Ru) containing dppe ligands were similarly obtained from protonation of the corresponding acetylide complexes via formation of vinylidene intermediate. Protonation of the acetylide complex containing a terminal alkynyl group [Ru]-CCCPh2CH2CCH (2c) generates the vinylidene complex {[Ru]=C=CHCPh2CH2CCH}BF4 (3c) which again undergoes an irreversible transformation to give {[Ru]=C=CHCH2CPh2CCH}BF4 (4c) possibly via a pi-coordinated alkynyl complex followed by hydrogen and metal migration. No similar transformation is observed for the analogous dppe complex 3c'. With an extra methylene group, complex {[Ru]=C=CHCPh2CH2CH2CH=CH2}BF4 (3d) and complex {[Ru]=C=CHCPh2CH2Ph}BF4 (3e) are stable. The presence of a gem-diphenylmethylene moiety at the vinylidene ligand with the appropriate terminal vinyl or alkynyl group along with the correct steric environment implements such a novel reactivity in the ruthenium vinylidene complexes. 相似文献
6.
反胶束法合成氧化锌微晶及其荧光特性 总被引:1,自引:0,他引:1
0引言材料的结构(微结构)、尺寸和形貌等因素对其特性及其实际应用具有重要的影响。对无机材料特别是氧化物半导体进行结构控制的研究近年来引起了人们极大的关注。氧化锌作为一种宽带隙(3.2eV)半导体材料,可广泛应用于压电材料、气体传感器、橡胶添加剂和光学器件等领域,而且还因其在室温下可产生激射现象使其成为纳米光学材料研究领域中的一大热点[1 ̄6]。目前,除了传统的固相-气相(V S)反应外,用于氧化锌微晶的制备方法主要有共沉淀法[7]、多羟基化合物水解法[8]、有机金属气相沉积法[9 ̄12]和水热法[13]等。通过选择不同的制备方法和… 相似文献
7.
A facile,one-pot synthesis of N-aryl propargylamine from aromatic boronic acid,aqueous ammonia,and propargyl bromide has been achieved under microwave-assisted conditions.The reactions can be smoothly completed within a total 10 min through a two-step procedure,including copper-catalyzed coupling of aromatic boronic acids with aqueous ammonia and following propargylation by propargyl bromide. 相似文献
8.
Chao-Yu Chen Yu-Ting Jhou Hui-Ling Lee Yu-Wen Lin 《Analytical and bioanalytical chemistry》2016,408(23):6295-6306
9.
Abstract A hydrophilic polymer membrane was synthesized with 2-hydroxyethyl methacrylate (HEMA) onto a Nylon 4 polymer backbone, PHEMA-g-N4. The membranes were water permselective because of the hydrophilicity, and the water permselectivity increased with increasing the degree of grafting. Permseparation of water was investigated with respect to the feed aqueous alcohol concentration, feed temperature, size of the alcohols, and degree of grafting. The separation factors of this PHEMA-g-N4 membrane were higher than those of the unmodified Nylon 4 membrane for pervaporation of aqueous ethanol solution, while the permeation rate was slightly lower. A separation factor of 98 and a 194 g/m2·h permeation rate could be obtained. Compared with an unmodified Nylon 4 membrane, the PHEMA-g-N4 membrane effectively increased the pervaporation separation index for the water-ethanol mixtures on pervaporation separation. 相似文献
10.
以CH3COOLi·2H2O、(CH3CO2)2Mn·4H2O、氧化物和柠檬酸为原料,采用流变相法经过2次灼烧后得到了不同氧化态离子掺杂的尖晶石化合物LiMn1.95M0.05O4(M:Li,Mg,Co,Ti,V)。通过X射线衍射测试技术对合成的产物物相进行表征,所得产物均具有纯相尖晶石结构。同时应用软件计算了其晶格常数,结果发现金属离子的掺杂不同程度地减少晶格大小。通过循环伏安法研究发现,在4V区域有2步可逆过程发生,对应于锂离子的脱嵌。掺杂的金属离子对于峰电位以及峰面积都有影响。Mn3 的含量越低,峰的面积越小。金属离子与氧的键能越大,峰电位越高。50次充放电循环测试表明,通过掺杂改性来改善尖晶石LiMn2O4的电化学性能时,在掺杂相同量阳离子的尖晶石化合物中,以选择氧化态为Co3 掺杂的化合物具有最佳的充放电容量和循环性能。 相似文献