论微极弹性动力学的一类守恒律

本文用无穷小变换群使作用量不变的思想,直接导出线性微极弹性动力学的一类守恒律,对线性均匀微极弹性固体证明了在纯量变换下不可能有守恒律,对线性微极弹性动力学而言,可看出守恒律(4.7)式是新的和独特的。     

Effects of Substrate Temperature on Helium Content and Microstructure of Nanocrystalline Titanium Films

Helium-charged nanocrystalline titanium films have been deposited by HeAr magnetron co-sputtering. The effects of substrate temperature on the helium content and microstructure of the nanocrystalline titanium films have been studied. The results indicate that helium atoms with a high concentration are evenly incorporated in the deposited titanium films. When the substrate temperature increases from 60℃ to 350℃ while the other deposition＇parameters are fixed, the helium content decreases gradually from 38.6 at.% to 9.2at.%, which proves that nanocrystalline Ti films have a great helium storage capacity. The 20 angle of the Bragg peak of （002） crystal planes of the He-charged Ti film shifts to a lower angle and that of （100） crystal plane is unchanged as compared with that of the pure Ti film, which indicates that the lattice parameter c increases and a keeps at the primitive value. The grain refining and helium damage result in the diffraction peak broadening.     

电子辐照诱发固态相变导致的氮化硼纳米结构生长

报道了N+离子轰击产生的氮化硼(BN)纳米结构,及在电子辐照时结构演化的高分辨透射电子显微镜的原位测定结果.应当强调的是,这种类富勒烯和发夹结构的演化,实际上是电子辐照诱发固态相变的发展,观察中发现的一些BN颗粒、卷曲物,可以被认为是类富勒烯等纳米结构形成的前体或早期阶段.提出了一种类富勒烯等结构的电子辐照动力学模型,并进行了讨论. 关键词： 氮化硼 电子辐照 透射电子显微镜 氮化硼纳米形成物     

含色散介质的一维光子晶体微腔的透射谱

研究了含色散介质的一维光子晶体微腔的透射谱,对色散介质采用Lorentz振子模型,腔模的频率设置在光子晶体带隙中心。发现当吸收可以忽略时,色散效应将导致在腔模附近有很高的态密度,与此相应地在透射谱中出现一个较宽的透射带。当吸收存在时透射带中心的透射峰消失,但带尾的透射峰依然存在。     

B物理中的难题

讨论单举B介子衰变中的难题, 包括直接CP非对称性及纵向极化分支比, 这些难题可能皆归因于量子色动力学的不准确度, 并非新物理的讯号.     

Influence of Yb-Doped Nanoporous TiO2 Films on Photovoltaic Performance of Dye-Sensitized Solar Cells

Yb-doped TiO2 pastes with different Yb/TiO2 weight ratios are prepared in the sol-gel process to obtain dyesensitized solar cells （DSCs）. The nanocrystalline size of Yb-TiO2 becomes smaller and the lattice parameters change. Lattice distortion is observed and dark current is detected. It is found that a part of Yb existing as insulating oxide Yb2O3 state acts as barrier layers at the electrode-electrolyte interface to suppress charge recombination. A Yb-doped TiO2 electrode applied in DSCs leads to a higher open-circuit voltage and a higher fill factor. How the Yb-doped TiO2 films affect the photovoltaic response of DSCs is discussed.     

第一届掺杂纳米材料发光性质学术会议

该会议为中国物理学会发光分会、中国稀土学会发光专业委员主办的国内首次纳米材料发光性质专题学术研讨会，旨在通过大会报告、专题研讨等活动，总结、交流近年来掺杂纳米发光材料及其相关应用领域所取得的研究进展和成果。在此基础上凝练科学目标、探讨和规划未来的学科发展方向并集中国内的优势资源攻克难点的科学问题，使我国在该研究领域更具国际竞争力。会议诚邀请该领域知名的专家和学者参加；在探索纳米世界之余，也将带您领略海南美丽而独特的自然景观和人文奇迹。     

微极各向同性弹性板中的Rayleigh-Lamb波

研究了无应力作用条件下，均匀、各向同性、圆柱形微极结构弹性板中波的传播．导出了对称和斜对称模式下波传播的特征方程．对短波这一极端情况，无应力圆板中对称和斜对称模态波的特征方程退化为Pmyle曲表面波频率方程．并得到薄板的计算结果．给出了位移和微转动分量，并绘制了相应图形．给出了若干特殊情况的研究结果及对称和斜对称模态特征方程的图示．     

Paper-like Microfibrous Nickel Catalyst for Hydrogen Production via NH3 Decomposition in Fuel Cell Applications

Recently, miniature H2 generator to power fuel cells for portable/micro electronic devices and passenger propulsion has been the focus of intense research activities1-3. One of the strategies is to find simple CO-free H2 production with novel microreactor…     

MORPHOLOGY OF BLACK CARBON AEROSOLS AND UBIQUITY OF 50-NANOMETER BLACK CARBON AEROSOLS IN THE ATMOSPHERE

Different-sized aerosols were collected by an Andersen air sampler to observe the detailed morphology of the black carbon （BC） aerosols which were separated chemically from the other accompanying aerosols, using a Scanning Electron Microscope equipped with an Energy Dispersive X-ray Spectrometer （SEM-EDX）. The results indicate that most BC aerosols are spherical particles of about 50 nm in diameter and with a homogeneous surface. Results also show that these particles aggregate with other aerosols or with themselves to form larger agglomerates in the micrometer range. The shape of these 50-nm BC spherical particles was found to be very similar to that of BC particles released from petroleum-powered vehicular internal combustion engines. These spherical BC particles were shown to be different from the previously reported fullerenes found using Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry （MALDI-TOF-MS）.