吉林球粒陨石（H5）的高压声速实验研究

 叙述了以透明材料作窗口，用辐射法测量吉林陨石的高压声速的原理、实验技术和实验结果，实验压力范围为42.2~113.2 GPa，得到了吉林陨石的高压声速随冲击压力的变化关系，并由此判断出吉林陨石在约65 GPa时发生相变。     

南丹铁陨石冲击绝热线和状态方程的研究

 用二级轻气炮作为加载工具，对南丹铁陨石进行了冲击压缩线测量，压力范围为62~208 GPa。用阻抗匹配法得出的南丹铁陨石冲击波速度D与粒子速度u之间的关系为：D=3.884+1.840u-0.12267u²（km/s），还据此确定了考虑到晶格非谐振项贡献的南丹铁陨石的三项式Grüneisen状态方程。     

激光拉曼谱仪氩离子激光器的更换与维修

激光拉曼谱仪氩离子激光器的更换与维修温为佑（中山大学测试中心广州５１０２７５）ＴｈｅＣｈａｎｇｅａｎｄＳｅｒｖｉｃｅｏｆＬａｓｅｒＲａｍａｎＳｐｅｃｔｒｏｍｅｔｅｒ￥ＷｅｎＷｅｉｙｏｕ（ＺｈｏｎｇＳｈａｎＵｎｉｖｅｒｓｉｔｙＧｕａｎｇｚｏｕ５１０２７...     

月球陨石的来源

2002年1月在阿曼发现的Say al Uhaymir(SaU)169陨石重206克，由碰撞熔化的角砾岩组成，含有极丰富的钾、稀土、磷等元素．瑞士伯尔尼地质研究所的Edwin Gnos和他的美国、英国、德国及瑞典的同事们分析了这颗陨石的钍、铀和钾的成分．发现它很可能是来自Imbrium陨石坑．这是至今发现的30颗月球陨石中惟一获得其原来在月球上的位置信息的一颗陨石．     

拉曼光谱在医学上的应用（Ⅱ）

拉曼光谱在医学上的应用（Ⅱ）余国滔（北京大学生命科学学院北京１００８７１）ＢｉｏｍｅｄｉｃａｌＡｐｐｌｉｃａｔｉｏｎｓｏｆＲａｍａｎＳｐｅｃｔｒｏｓｃｏｐｙ（Ⅱ）ＹｕｅＫｗｏｋｔｏ（ＣｏｌｅｇｅｏｆＬｉｆｅＳｃｉｅｎｃｅｓ，ＰｅｋｉｎｇＵｎｉｖｅｒｓ...     

原卟啉（PP）和血卟啉（HP）对DNA空间结构微观光敏损伤的特征

原卟啉（ＰＰ）和血卟啉（ＨＰ）对ＤＮＡ空间结构微观光敏损伤的特征许以明，张志义（中国科学院生物物理研究所北京１００１０１）ＣｈａｒａｃｔｅｒｏｆＭｉｃｒｏｃｏｓｍｉｃａｎｄＰｈｏｔｏｓｅｎｓｉｔｖｅＤａｍａｇｅｏｆＰＰａｎｄＨＰｔｏＴｈｅｓｐａｃｅＳ...     

200 nm Supercontinuum Generated by Subpicosecond Optical Pulses and its Evolution Process Observation

Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｗｈｅｎｕｌｔｒａｓｈｏｒｔｏｐｔｉｃａｌｐｕｌｓｅｓｗｉｔｈｈｉｇｈｉｎｔｅｎｓｉｔｙ（ｐｕｍｐｉｎｇｌｉｇｈｔ）ａｒｅｉｎｊｅｃｔｅｄｉｎｔｏｄｉｓｐｅｒｓｉｏｎｓｈｉｆｔｅｄｆｉｂｅｒ（ＤＳＦ）,ｄｕｅｔｏｔｈｅｎｏｎｌｉｎｅａｒｅｆｆｅｃｔｓｉｎｆｉｂｅｒｓｕｃｈａｓｓｅｌｆｐｈａｓｅｍｏｄｕｌａｔｉｏｎ（ＳＰＭ）,ｆｏｕｒｗａｖｅｍｉｘｉｎｇ（ＦＷＭ）,ｃｒｏｓｓｐｈａｓｅｍｏｄｕｌａｔｉｏｎ（ＸＰＭ）ａｎｄｓｔｉｍｕｌａｔｅｄＲａｍａｎｓｃａｔｔｅｒｉ…     

拉曼光活性(ROA)经典理论模型研究

拉曼光活性（ＲＯＡ）经典理论模型研究马树国吴国祯（清华大学物理系北京１０００８４）ＡＣｌａｓｉｃａｌＴｈｅｏｒｙｆｏｒｔｈｅＲａｍａｎＯｐｔｉｃａｌＡｃｔｉｖｉｔｙＭａＳｈｕｇｕｏ，ＷｕＧｕｏｚｈｅｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，Ｔｓｉｎ...     

Phase Modulation in Multiline Raman Amplification

１ＩｎｔｒｏｄｕｃｔｉｏｎＢｒｏａｄｂａｎｄｓｔｉｍｕｌａｔｅｄＲａｍａｎｓｃａｔｅｒｉｎｇ（ＳＲＳ）ｈａｓｂｅｅｎｕｓｅｄｉｎａｎｕｍｂｅｒｏｆｆｉｅｌｄｓ，ｉｎｃｌｕｄｉｎｇｗａｖｅｌｅｎｇｔｈｃｏｎｖｅｒｓｉｏｎ，ｂｅａｍｃｌｅａｎｕｐａｎｄｐ...     

Optical Associative Memory Based on Double Phase Conjugation Using Bi_（12）TiO_（20） Photorefractive Fi

ＯｐｔｉｃａｌＡｓｓｏｃｉａｔｉｖｅＭｅｍｏｒｙＢａｓｅｄｏｎＤｏｕｂｌｅＰｈａｓｅＣｏｎｊｕｇａｔｉｏｎＵｓｉｎｇＢｉ＿（１２）ＴｉＯ＿（２０）ＰｈｏｔｏｒｅｆｒａｃｔｉｖｅＦｉｂｅｒ￥ＬＩＵＳｈｕｔｉａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，...     

Granular Leidenfrost effect in vibrated beds with bumpy surfaces

The effects of subjecting a bed of granular materials to horizontal vibrations by a bumpy oscillating surface have been investigated computationally in this study. The behaviour of the granular bed is determined by the vibration conditions applied which include the vibrating frequency and amplitude as well as the bumpiness of the oscillating surface. Under sufficiently vigorous vibration conditions, the granular Leidenfrost effect whereby the entire granular bed is levitated above the vibrating base by a layer of highly energetic particles may be observed. Granular temperature profiles of systems that exhibit the granular Leidenfrost effect indicate an unequal distribution of energy between particles near the vibrating base and those in the bulk. A bumpy oscillating surface was also observed to be more effective at introducing perturbations and transferring energy into a granular bed. The granular Leidenfrost effect can be induced by the application of larger grain sizes of particles constituting the bumpy vibrating base under vibration conditions that are normally insufficient for the onset of the effect. Lastly, a phase diagram which can be utilized for predicting the behaviours of granular beds that are subjected to oscillations by various types of bumpy surfaces has been constructed based on the simulation results obtained.     

Mössbauer Method for Studying Vibrations in a Granular Medium Excited by Ultrasound

JETP Letters - Vibrations of a granular medium immersed in epoxy resin without a hardener have been studied by Mössbauer spectroscopy. The granular medium consists of small potassium...     

Temperature Properties in Polydisperse Granular Mixtures

Numerical simulations are employed to consider the problem of determining the granular temperatures of the species of a homogeneous heated granular mixture with a power-law size distribution. The partial granular temperature ratios are studied as functions of the fractal dimension D, the restitution coefficient e, the rescaled viscosity time, the average occupied area fraction φ, the total particle number N and the number fraction. Different species of particles in a power-law system typically do not have the same mean kinetic energy, namely the granular temperature. It is found that the extent of nonequipartition of kinetic energy is determined by the fractal dimension D, the restitution coefficient e and the rescaled viscosity time, while is insensitive to the total particle number N , the area fraction φ and the number fraction.     

Granular cooling of hard needles

We have developed a kinetic theory of hard needles undergoing binary collisions with loss of energy due to normal and tangential restitution. In addition, we have simulated many particle systems of granular hard needles. The theory, based on the assumption of a homogeneous cooling state, predicts that granular cooling of the needles proceeds in two stages: An exponential decay of the initial configuration to a state where translational and rotational energies take on a time independent ratio (different from unity), followed by an algebraic decay of the total kinetic energy of approximately t(-2). The simulations support the theory very well for low and moderate densities. For higher densities, we have observed the onset of the formation of clusters and shear bands.     

Granular flow: Dry and wet

Granular material is a collection of macroscopic particles that are visible with naked eyes. The non-equilibrium nature of the granular materials makes their rheology quite different from that of molecular systems. In this minireview, we present the unique features of granular materials focusing on the shear flow of dry granular materials and granule-liquid mixture.     

Evolution of Energy in Submerged Granular Column Collapse

The evolution of energy in subaerial and subaqueous granular column collapses is studied.Employing the refractive index matching method and planar laser-induced fluorescence technique,we obtain granular and liquid images simultaneously in a single experiment of subaqueous flow.Particle image velocimetry and particle tracking velocimetry are used to process the data for the fluid and granular phase.We find stepwise decreases in the total kinetic energy of the granular material.The stage of rapidly falling energy corresponds to large transverse changes in the direction of the massive granular particles.Moreover,in this stage,a major fraction of the granular kinetic energy transferred from the granular potential energy is lost or transferred.Interestingly,compared with dry granular flow,the existence of an ambient liquid seems to reduce the total dissipated energy,which may be the reason why previous studies observed similar granular runout distances in subaqueous and dry granular collapses.     

Granular packing as model glass formers

Static granular packings are model hard-sphere glass formers. The nature of glass transition has remained a hotly debated issue. We review recent experimental progresses in using granular materials to study glass transitions. We focus on the growth of glass order with five-fold symmetry in granular packings and relate the findings to both geometric frustration and random first-order phase transition theories.     

Granular flows

We review both experimental and theoretical works concerning granular flows. We successively address the regime of slow deformations, which is mainly governed bystericinteractions and frictionforces, thenthe rapid flow regime, whichdeals with inelastic collisions, and lastly the regime of intermittent avalanches.