以Dirac测度为源的拟线性退化抛物方程

本文讨论拟线性退化抛物方程 ut-△um=δ(x), (A)(x,t)∈Q带有初值条件 u(x,0)=u0(x), (A)x∈Rn 的Cauchy问题,其中δ(x)是Dirac测度,m＞1,Q≡Rn×(0,+∞),u0(x)≥0,u0(x)∈Cβ(Rn),β∈(0,1)且0∈suppu0=-Ω,Ω是Rn中的一个有界开集,证明了弱解的存在性.此外,还讨论了自由边界的Holder连续性.     

IRIS／AP－ICP－AES法测定BaBPO_5晶体中Ba、B、P的含量

本文使用美国ＴｈｅｒｍｏＪａｒｒｅｌｌＡｓｈ公司先进的ＩＲＢ／ＡＰ全谱直读等离子体光谱仪，用酸溶样和碱熔样两种方法测定了ＢａＢＰＯ_５晶体中Ｂａ、Ｂ、Ｐ的含量，得到了良好的精密度和准确度，相对标准偏差均小于１％，回收率在９８％─１０３％之间。     

On Bounded Positive (m,p)-Circle Domains

Let D be a bounded positive (m, p)-circle domain in ?². The authors prove that if dim(Iso(D)⁰) = 2, then D is holomorphically equivalent to a Reinhardt domain; if dim(Iso(D)⁰) = 4, then D is holomorphically equivalent to the unit ball in ?². Moreover, the authors prove the Thullen’s classification on bounded Reinhardt domains in ?² by the Lie group technique.     

On Bounded Positive(m,p)-Circle Domains

Let D be a bounded positive(m, p)-circle domain in C~2. The authors prove that if dim(Iso(D)~0) = 2, then D is holomorphically equivalent to a Reinhardt domain; if dim(Iso(D)~0) = 4, then D is holomorphically equivalent to the unit ball in C~2. Moreover,the authors prove the Thullen's classification on bounded Reinhardt domains in C~2 by the Lie group technique.     

对奥运会中越轨行为的研究

在全球变暖日益加剧的背景下,人们对环境问题的关注度越来越高,世界各国都在为推进低碳经济发展努力减少碳足迹．对于初中学生进行低碳环保教育也同样引起人们的重视．不少教师认为,低碳在学校教育中的应用,主要表现在无纸化办公、自制教具、培养学生的环保、节约意识等;而通过一段时间的实践研究后,大家发现低碳教学的核心在于更深层次的“严谨从容,惜时高效”,即一般意义上所说的：轻负担、高效率．由此,课题研究从形式走向本质．具体到初中数学课堂教学上,低碳课堂的“高效性”主要有三个方面的特点．     

Fabrication of an Anti-Reflective Microstructure on ZnS by Femtosecond Laser Bessel Beams

As an important mid-infrared to far-infrared optical window, ZnS is extremely important to improve spectral transmission performance, especially in the military field. However, on account of the Fresnel reflection at the interface between the air and the high-strength substrate, surface optical loss occurs in the ZnS optical window. In this study, the concave antireflective sub-wavelength structures (ASS) on ZnS have been experimentally investigated to obtain high transmittance in the far-infrared spectral range from 6 μm to 10 μm. We proposed a simple method to fabricate microhole array ASS by femtosecond Bessel beam, which further increased the depth of the microholes and suppressed the thermal effects effectively, including the crack and recast layer of the microhole. The influence of different Gaussian and Bessel beam parameters on the microhole morphology were explored, and three ASS structures with different periods were prepared by the optimized Bessel parameters. Ultimately, the average transmittance of the sample with the ASS microhole array period of 2.6 μm increased by 4.1% in the 6 μm to 10 μm waveband, and the transmittance was increased by 5.7% at wavelength of 7.2 μm.     

Finite Velocity of the Propagation of Perturbations for a Class of Non-Newtonian Fluids

In this paper, we consider the initial boundary value problem of a class of non-Newtonian fluids. We obtain that finite velocity of the propagation of perturbations.     

Adsorption of 4,4′‐thiobisbenzenethiol on silver surfaces: surface‐enhanced Raman scattering study

Adsorption of 4,4′‐thiobisbenzenethiol (4,4′‐TBBT) on a colloidal silver surface and a roughened silver electrode surface was investigated by means of surface‐enhanced Raman scattering (SERS) for the first time, which indicates that 4,4′‐TBBT is chemisorbed on the colloidal silver surface as dithiolates by losing two H‐atoms of the S H bond, while as monothiolates on the roughened silver electrode. The different orientations of the molecules on both silver surfaces indicate the different adsorption behaviors of 4,4′‐TBBT in the two systems. It is inferred from the SERS signal that the two aromatic rings in 4,4′‐TBBT molecule are parallel to the colloidal silver surface as seen from the disappearance of ν_{C H} band (3054 cm⁻¹), which is a vibrational mode to be used to determine the orientation of a molecule on metals according to the surface selection rule, while on the roughened silver electrode surface they are tilted to the surface as seen from the enhanced signal of ν_{C H}. The orientation of the C‐S bond is tilted with respect to the silver surface in both cases as inferred from the strong enhancement of the ν_{C S}. SERS spectra of 4,4′‐TBBT on the roughened silver electrode with different applied potentials reveal that the enhancement of 4,4′‐TBBT on the roughened silver electrode surface may be related to the chemical mechanism (CM). More importantly, the adsorption of 4,4′‐TBBT on the silver electrode is expected to be useful to covalently adsorb metal nanoparticles through the free S H bond to form two‐ or three‐ dimensional nanostructures. Copyright © 2007 John Wiley & Sons, Ltd.     

Hopf–Hopf bifurcation analysis based on resonance and non-resonance in a simplified railway wheelset model

Nonlinear Dynamics - This paper mainly investigates the dynamics of the non-resonant and near-resonant Hopf–Hopf bifurcations caused by the interaction of the lateral and yaw motion in a...     

Hydration-Facilitated Fine-Tuning of the AIE Amphiphile Color and Application as Erasable Materials with Hot/Cold Dual Writing Modes

Hydration water greatly impacts the color of inorganic crystals, but it is still unknown whether hydration water can be utilized to systematically manipulate the emission color of organic luminescent groups. Now, metal ions with different hydration ability allow fine-tuning the emission color of a fluorescent group displaying aggregation induced emission (AIE). Because the hydration water can be removed easily by gentle heating or mechanical grinding and re-gained by solvent fuming, rewritable materials can be fabricated both in the hot-writing and cold-writing modes. This hydration-facilitated strategy will open up a new vista in fine-tuning the emission color of AIE molecules based on one synthesis and in the design of smart luminescent devices.