Shock-Induced Near-Wall Two-Phase Flow Structure Over a Micron-Sized Particles Bed

The present paper studies numerical modelling of near-wall two-phase flows induced by a normal shock wave moving at a constant speed, over a micronsized particles bed. In this two-fluid model, the possibility of particle trajectory intersection is considered and a full Lagrangian formulation of the dispersed phase is introduced. The finiteness of the Reynolds and Mach numbers of the flow around a particle as well as the fineness of the particle sizes are taken into account in describing the interactions between the carrier- and dispersed- phases. For the small mass-loading ratio case, the numerical simulation of flow structure of the two phases is implemented and the profiles of the particle number density are obtained under the constant-flux condition on the wall. The effects of the shock Mach number and the particle size and material density on particle entrainment motion are discussed in detail.The obtained results indicate that interphase non-equilibrium in the velocity and temperature is a common feature for this type of flows and a local particle accumulation zone may form near the envelope of the particle trajectory family.

Nonvolatile holograms in LiNbO3 : Fe : Cu by use of the bleaching effect

We report our observation of a bleaching effect under an ultraviolet exposure in LiNbO3:Fe:Cu crystals. Two three-step recording-transferring-fixing schemes are proposed to record nonvolatile photorefractive holograms in such crystals. In the schemes two red laser beams and an ultraviolet illumination are used selectively to write the charge grating in the shallow-level Fe centers, to develop the charge grating in the deep-level Cu centers by transferring the charge grating in the Fe centers, and to fix only the charge grating in the Cu centers for unerasable read-out. Experimental results, verifications, and an optimal recording scheme are given. A comparison of the lithium niobate crystals of the same double-doping system of Fe:Mn, Ce:Mn, Ce:Cu, and Fe:Cu is outlined. (C) 2002 Optical Society of America.

Fabrication and spectral properties of Nd3+-doped yttrium lanthanum oxide transparent ceramics

Transparent 1 at% Nd3+:Y1.9La0.1O3 ceramics were fabricated with nanopowders prepared by carbonate coprecipitation method. The powder compacts were sintered in H-2 atmosphere at 1550 degrees C for 30 h. The Nd3+:Y1.9La0.1O3 ceramics display uniform grains of about 50 mu m and high transparency. The highest transmittance of the ceramics reaches 67%. The strongest absorption peak is in the wavelength of 820 nm with absorption cross section of 2.48 x 10(-20) cm(2). The absorption is still high at LD wavelength 806 nm with absorption cross section of 1.78 x 10(-20) cm(2) and broad full width at half maximum (FWHM) of about 6.3 nm. The strongest emission peak was centered at 1078 nm with large stimulated emission cross section of 9.63 x 10(-20) cm(2) and broad FWHM of about 7.8 nm. The broad absorption and emission bandwidth of Nd3+:y(1.9)La(0.1)O(3) transparent ceramics are favorable to achieve the miniaturized LD pumping apparatus and ultrashort modelocked pulse laser output, respectively. (c) 2007 Elsevier B.V. All rights reserved.

云南文山黄牛和迪庆黄牛的遗传多样性比较研究

本文通过细胞遗传学、mtDNARFLP（线粒体DNA、限制性片段长度多态性）和血液蛋白及同工酶3个方面的研究，分析了云南文山黄牛和迪庆黄牛的遗传多样性和遗传分化关系。结果：（1）细胞遗传学云南两个地方黄牛品种的Y染色体形态及其C一带具有显著多态性。文山黄牛和迪庆黄牛分别为一小的近端部和亚申部（或中部）着丝位Y染色体，并分别在Y染色体的臂端部和短臂的臂端部显示弱阳性C一带，说明文山黄牛的父系起源可能是瘤牛（Bosindicus），而迪庆黄牛是普遍牛（Bostaurus）。推测两种Y染色体可能是臂问倒位的结果。（2）mtD－NARFLP两个黄牛品种的111个个体的mtDNA经8种限制性内切酶酶切后，有个酶表现出多态，共检测到17种限制性态型。归结出的3种基因单倍型，分别是A－A－A－A－A－A－A型（瘤斗）、B－B－B－B－B—B－B型（普通型）和A－C－B－B－C－A－A型（耗半Bosgrunniens）。从基因单倍型在群体中的表现可看出，文山黄牛和迪庆黄牛都具有瘤牛和普通牛两种母系起源。但文山黄牛以瘤牛血统为主，迪庆黄牛以普通牛血统为主，而且还可能含有部价耗牛的血统。（3）血液蛋白及同工酶分析了两个黄牛品种的...

湖南烙铁头蛇毒中一个新的舒缓激肤增强肤( TmF)

通过70%冷甲醇抽提、Sephadex C i-15分子筛和反相高效液相色谱G8层析，从湖南产烙铁头蛇毒(Trineresurus muqua nwtus)冻干粉中纯化得到一个新的舒缓激肤增强肤(BPP)，命名为TmF。该小肤的氨基酸序列为p(irr (iy Arg Pro, Leti (iy Pro, Pro, Ile- Pro, Pro ( pau表示焦谷氨酸)。序列结果分析表明，TmF和已经分离得到的BPPs有很高的序列同源性。MSI- MS 测定其分子量为1 .1107 kD o TmF的生物学活性和药理学活性检测的结果表明，它增强舒缓激肤(BK)(1 mg/L)诱导的离体豚 鼠回肠纵行肌收缩的活性为(1 .13士0 .3)单位(mg/ L) ; TmF (5 .0 x 10- 0 mg/ kg)可以增强约(14士2) mmHg的由BK(5 . Ox 10-' mg/ kg)诱导的舒张压下降;在抑制剂试验中，不同剂量的TmF和5x1。一zmg的血管紧张素转化酶保温30 min，结果表明大约 2.0x10一3mg的TmF表现出对ACE水解活性的半数抑制率(IQo )。

底栖藻类对氮、磷去除效果研究

通过模拟实验探讨了污水处理中底栖藻类的群落结构、生长状况及其对氮(N)、磷(P)的去除能力。实验期间,被试藻类(丝状绿藻占优势)在污水中生长良好,培养5 d后收获的藻类生物量可达14.36±0.72 g;污水总氮(TN)、总磷(TP)含量分别由36.97±0.26 m g.L-1、2.88±0.02 m g.L-1降至1.44±0.09 m g.L-1、0.07±0.01 m g.L-1,对氨氮(NH4-N)和硝氮(NO3-N)的去除率亦达95%以上;藻体总凯氏氮(TKN)和TP含量分别为5.75±0.2

Mitochondrial 16S rRNA sequence variations and phylogeny of the Chinese sisorid catfishes

Partial sequences of mitochondrial 16S rRNA gene were obtained by PCR amplification for comparisons among nine species of glyptosternoid fishes and six species of non-glyptosternoids representing 10 sisorid genera. There are compositional biases in the A-rich impaired regions and G-rich paired regions. A-G transitions are primarily responsible for the Ts/Tv bias in impaired regions. The overall substitution rate in impaired regions is almost two times higher than that in the paired regions. Saturation plots at comparable levels of sequence divergence demonstrate no saturation effects. Phylogenetic analyses using both maximum likelihood and Bayesian methods support the monophyly of Sisoridae. Chinese sisorid catfishes are composed of two major lineages, one represented by (Gagata (Bagarius, Glyptothorax)) and the other by "glyptosternoids + Pseudecheneis". The glyptosternoids may not be a monophyletic group. A previous hypothesis referring to Pseudecheneis as the sister group of monophyletic glyptosternoids, based on morphological evidence, is not supported by the molecular data. Pseudecheneis is shown to be a sister taxon of Glaridoglanis. Pareuchiloglanis might be paraphyletic with Pseudexostoma and Euchiloglanis. Our results also support the hypothesis that Pareuchiloglanis anteanalis might be considered as the synonyms of Pareuchiloglanis sinensis, and genus Euchiloglanis might have only one valid species, Euchiloglanis davidi.

双源电子束蒸发制备Si/SiO2光学薄膜的工艺

用双源电子束蒸发的方法,在K9玻璃基片上蒸镀Si和SiO2的混合膜.通过改变两种膜料蒸发速率的比例,得到的各个膜层,其折射率大小在两种膜料折射率之间的范围内变化.从实验上得出了混合膜层的折射率随Si和SiO2蒸发速率比变化的规律,并讨论了这种淀积方法的优越性.