Reissner-Nordstr(o)m de Sitter黑洞的量子隧穿效应

运用Parikh的量子隧穿模型,研究了Reissner-Nordstr(o)m de Sitter黑洞的量子隧穿效应.结果表明,在能量守恒的条件下,黑洞外视界和宇宙视界处的粒子出射率与Bekenstein-Hawking熵有关,辐射谱不再是严格的纯热谱.     

Tunneling Radiation of a Torus-Like Black Hole in Anti-de Sitter Space-Time

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.     

多项式理想准素分解的算法

讨论了多项式理想准素分解的算法,对于理想坐标变换中关键的“一般位置”的计算,给出了一个确定算法,并建立了特别规范Groebner基的概念,利用这一概念及文中提供的相应算法,可以方便地计算理想的维数,进而使用降维的方法来得到高维理想的准素分解。     

Hawking Radiation of Charged Particles via Tunne ling from a Cylindrically Symmetric Black Hole in Anti-de Sitter Space-Time

Applying Parikh-Wilzcek‘s semi-classical quantum tunneling model, we study the Hawking radiation of charged particles as tunneling from the event horizon of a cylindrically symmetric black hole in anti-de Sitter space-time.The derived result shows that the tunneling rate of charged particles is related to the change of Bekenstein-Hawking entropy and that the radiation spectrum is not strictly pure thermal after taking the black hole background dynamical and self-gravitation interaction into account, but is consistent with the underlying unitary theory.     

Microchip capillary electrophoresis with amperometric detection for several carbohydrates

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.     

超声波作用下芳亚甲基丙二酸亚异丙酯的合成

在超声波辐射下，以芳香醛、丙二酸亚异丙酯为原料，乙醇作溶剂，无催化剂 作用下合成了芳亚甲基丙二酸亚异丙酯。该方法操作简便，不污染环境，产率较高 ，为该类化合的合成提供了一种有效的新方法。     

Fe3O4/TiO2 纳米材料靶上脱盐的基质辅助激光解析/电离质谱新方法研究

建立了一种简便、高效的靶上脱盐新方法。利用Fe3O4/TiO2磁性纳米材料对肽段的吸附作用,将其作为载体用于靶上肽段富集和脱盐。在对纳米材料使用量、浸洗条件进行优化的基础上,成功地鉴定了溶于10mol/L尿素溶液的100fmol的肌红蛋白样品,也对溶于3mol/L尿素溶液中的10fmol的肌红蛋白样品进行了成功地分析鉴定。通过对肌红蛋白样品进行预处理和质谱分析重复实验,表明该方法重现性好,且简便、高效,所需时间短,一次可同时处理多个样品,易于实现通量化,为有效地解决目前蛋白质组分析中所面临的基质辅助激光解析/离子化飞行时间质谱耐盐性差的问题提供了一种新的手段。     

聚苯胺/二氧化钛复合薄膜的制备及其气敏性能

室温条件下, 运用静电力自组装和原位化学氧化聚合相结合的方法制备了聚苯胺/纳米二氧化钛(PANI/TiO2)复合薄膜和聚苯胺(PANI)薄膜, 并通过XPS和SEM对薄膜进行了分析表征. 采用平面叉指电极式器件制备了PANI/TiO2复合薄膜和PANI薄膜气体传感器, 研究了其在常温下对有毒气体NH3和CO 的敏感性能. 结果表明, PANI/TiO2复合薄膜较PANI薄膜具有更优的灵敏度和响应恢复特性.     

Intramolecular metathesis of a vinyl group with vinylidene C=C double bond in Ru complexes

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.     

反胶束法合成氧化锌微晶及其荧光特性

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…