A New Method for the Analysis of Relative Permeability in Porous Media

By combining three-dimensional digital microtomography techniques with the lattice Boltzmann method,a new methodology is used to analyse the relative permeability of multiphase flow in porous media.The results indicate that the two coupling coefficients K12 and K21 have the same magnitude,therefore the Onsager reciprocity still holds,the results also agree well with the results of pipe flow numerical experiments.     

Fabrication of Dendrimer－like PAMAM Based on Silica Nanoparticles

A G 4.0 dendrimer-like poly (amido amine) (PAMAM) based on silica nanoparticles was fabricated via a divergent approach.It was built from γ-aminopropyi silica nanoparfides (APSN) core via repetitive addition of acrylate (MA) and hexylenediamine (HDA). FT-IR and EA were used to monitor the progress of dendrimer during each step. The amino group content of the resulting product increased from 0.49 to 3.72 mmol/g after the 4th generation. In addition, the percentage of grafting increased with increasing generation and reached to 65.9% after 4th generation. It was found that the resulting silica nanoparticles could be dispersed in methanol with a mean hydrodynamic particle diameter of 152.7 nm although the silica nanoparticles had agglomerated during the storage period.     

双预脉冲驱动X射线激光实验研究

 在“星光-Ⅱ”激光装置上进行了双预脉冲驱动类氖铬X射线激光实验，介绍了实验方法和实验结果，并对结果进行了简短讨论。由于目前“星光”装置输出能量较低，所进行的双预脉冲驱动未能显著提高X射线激光强度，改变预脉冲幅度时X射线激光强度也未有显著变化。利用MED103程序进行了模拟计算，其结果与实验结果一致。     

BIN PACKING中γm≤1.20的直接证明

ＢＩＮＰＡＣＫＩＮＧ中γ_ｍ≤１．２０的直接证明刘明堂，越民义（中国科学院应用数学研究所，北京１０００８０）ＡＤＩＲＥＣＴＰＲＯＯＦＯＦＴＨＥＩＮＥＱＵＡＬＩＴＹγ_ｍ≤１．２０ＩＮＭＵＬＴＩＰＲＯＣＥＳＳＯＲＳＣＨＥＤＵＬＩＮＧ￥ＬＩＵＭＩＮＧＴＡＮ...     

绝缘层上半导体多晶膜激光再结晶临界条件

从理论的角度分析了绝缘衬底对其上面半导体多晶膜激光熔化再结晶过程的影响, 发现低导热的绝缘层使产生固一液相变的临界激光功率有明显的降低.用喇曼光谱测量了激光再结晶SOI层中的应力. 应力的出现是多晶膜内曾经发生过固一液相的佐证.从这一思想出发, 对LPCVD方法制备的大量SOI 样品进行激光再结晶临界条件的研究, 证明了忽略绝缘层低热导影响的模型不能解释实验结果, 而经过修正的公式则可以较好地拟合实验结果, 关键词：     

Compact Single-Stage Femtosecond Multipass Ti：Sapphire Amplifier at 1 kHz with High Beam Quality

A compact femtosecond Ti：sapphire amplifier system is reported using single-stage multipass configuration with high beam quality. A high dispersion glass stretcher and a pair of double prisms for compression are introduced based on broadband femtosecond seed pulses. The non-grating-based pulse stretcher and compressor are advantageous to increase high beam quality and to reduce the high-order dispersion. A Gaussian filter is used to reduce the gain narrowing effect in amplification. The compact femtosecond Ti：sapphire nine-pass amplifier delivers pulses with a duration of 26 fs and an energy of 800μJ at 7mJ pumping pulses energy at I kHz. The 1-kHz femtosecond amplifier with high beam quality and high stability is very suitable for ultrafast physics research applications, such as attosecond science, ultra-precision micromachining, and THz wave generation.     

第32届国际数学奥林匹克试题及解答

1.(苏联提供)已给△ABC,设I是它的内心,角A,B,C的内角平分线分别与其对边交于A′,B′,C′。求证     

Average Property of Isospin Effects Induced by Neutron-Halo Nuclei

We study the average property of the isospin effects of reaction mechanism induced by neutron-halo nuclei within the isospin-dependent quantum molecular dynamics model. We find that the extended neutron density distribution for the neutron-halo projectile brings an important isospin effect into the reaction mechanism, which induces the decrease of nuclear stopping R; however, it induces the obvious increases of the neutron-proton ratio of nucleon emissions （n/p）nucl for all of the beam energies in this work, compared to the same mass stable colliding system.     

气密性碳涂覆光纤筛选强度与电阻关系研究

通过实验分析确立了把光纤电阻作为衡量气密性碳涂覆光纤通过２％应变筛选的过渡标准。要拉制２％应变筛选的碳涂覆光纤，其电阻值应小于３０ｋΩ／ｃｍ。     

三硼酸锂晶体的生长形态

用自由生长系统研究了三硼酸锂ＬｉＢ_３Ｏ_５（ＬＢＯ）晶体的实际生长形态。实验表明，它的各晶面簇的重要性的顺序为：｛１１０｝＞｛０１１｝＞｛２０１｝＞｛１１１｝。讨论了ＬＢＯ晶体的生长习性与内部结构之间的关系并应用负离子配位多面体理论模型解释了ＬＢＯ晶体的生长形态。