Nonequilibrium microstructures and their evolution in a Fe-Cr-W-Ni-C laser clad coating

The laser-solidified microstructural and compositional characterization and phase evolution during tempering at 963 K were investigated using an analytical transmission electron microscope with energy dispersive X-ray analysis. The cladded alloy, a powder mixture of Fe, Cr, W, Ni, and C with a weight ratio of 10:5:1:1:1, was processed with a 3 kW continuous wave CO2 laser. The processing parameters were 16 mm/s beam scanning speed, 3 mm beam diameter. 2 kW laser power, and 0.3 g/s feed rate. The coating was metallurgically bonded to the substrate, with a maximum thickness of 730 mu m, a microhardness of about 860 Hv and a volumetric dilution ratio of about 6%. Microanalyses revealed that the cladded coating possessed the hypoeutectic microstructure comprising the primary dendritic gamma-austenite and interdendritic eutectic consisted of gamma-austenite and M7C3 carbide. The gamma-austenite was a non-equilibrium phase with extended solid solution of alloying elements and a great deal of defect structures, i.e. a high density of dislocations, twins, and stacking faults existed in gamma phase. During high temperature aging, in situ carbide transformation occurred of M7C3 to M23C6 and M6C. The precipitation of M23C6, MC and M2C carbides from austenite was also observed.

Microcracks Propagation in One Al/SiCp under Impact Loading

Numerous microcracks propagation in one metal matrix composite, Al/SiCp under impact loading was investigated. The test data was got with a specially designed impact experimental approach. The analysis to the density, nucleating locations and distributions of the microcracks as well as microstructure effects of the original composite was received particular emphasis. The types of microcracks or debonding nucleated in the tested composite were dependent on the stress level and its duration. Distributions of the microcracks were depended on that of microstructures of the tested composite while total number of microcracks in unit area and unit duration, was controlled by the stress levels. Also, why the velocity was much lower than theoretical estimations for elastic solids and why the microcracks propagating velocities increased with the stress levels' increasing in current experiments were analysed and explained.

Application of Optical Protein-chip in Detecting Phage M13KO7

Abstract: Avidin layer was bound on the substrate surface of Silicon wafer modified with aldehyde. The interaction between avidin and biotin was adopted for the immobilization of mouse monoclonal biotin-anti-M13 (antibody GP3)-labeled biotin. The surface was incubated in a solution containing phage M13KO7, which was trapped by the antibody GP3 with the interaction between phage M13KO7 and antibody GP3, resulting in a variation of layer thickness that was detected by imaging ellipsometry. The results showed a saturated layer of antibody GP3 with a thickness about 6.9 nm on the surface of the silicon wafer. The specific interaction between phage M13KO7 and antibody GP3 resulted in a variation of layer thickness. The layer of phage M13KO7 bound with antibody GP3 was 17.5 nm in the concentration of 1.1×1010 pfu/mL. Each variation of the layer thickness corresponded to a concentration of phage M13KO7 in the range of 0.1×1010–2.5×1010 pfu/mL, with the sensitivity of 109 pfu/mL. Compared with other methods, the optical protein-chip, requiring only short measurement time, label free, is a quantitative test, and can be visualized. This study could be significant on the interactions between the antibody and the virus, showing potential in the early diagnosis of virosis.

Experimental Investigation On The Holdup Distribution Of Oil-Water Two-Phase Flow In Horizontal Parallel Tubes

An experimental investigation was conducted to study the holdup distribution of oil and water two-phase flow in two parallel tubes with unequal tube diameter. Tests were performed using white oil (of viscosity 52 mPa s and density 860 kg/m(3)) and tap water as liquid phases at room temperature and atmospheric outlet pressure. Measurements were taken of water flow rates from 0.5 to 12.5 m(3)/h and input oil volume fractions from 3 to 94 %. Results showed that there were different flow pattern maps between the run and bypass tubes when oil-water two-phase flow is found in the parallel tubes. At low input fluid flow rates, a large deviation could be found on the average oil holdup between the bypass and the run tubes. However, with increased input oil fraction at constant water flow rate, the holdup at the bypass tube became close to that at the run tube. Furthermore, experimental data showed that there was no significant variation in flow pattern and holdup between the run and main tubes. In order to calculate the holdup in the form of segregated flow, the drift flux model has been used here.

The magnetohydrostatic equilibrium of horizontal prominence of torus configuration

There are several examples of horizontal ringlike prominences in the observations of Ha monochromatic image of the sun. In the present paper the statie equilibrium of the plasma loop is discussed. The analytic solutions to magnetic field and density are obtained for the axisymmetrie case under the closed boundary condition. Results show the great influence of the gravity and different force-free factors on the configurations of magnetic surfaces and the distributions of thermodynamical quantities for the prominence.

THE FORMATION MECHANISM OF THE VITRIFIED SLAG IN A PLASMA ARC REACTOR FOR HAZARDOUS WASTE TREATMENT

Various hazardous wastes with additives have been vitrified to investigate the formation mechanism of the glassy slag by a 30 kW DC plasma-arc reactor developed by the Institute of Mechanics, Chinese Academy of Sciences. The average temperature in the reaction area is controlled at 1500°C. The chemical compositions of three sorts of fly ashes are analyzed by XRF (X-Ray Fluorescence). Fly ashes with vitrifying additives can be vitrified to form glassy slag, which show that the ratio of the whole oxygen ions to the whole network former ions in glass (R) is appropriate in the range of 2~3 to form durable vitrified slag. In this experiment, the arc power is controlled below 5 kW to inhibit waste evaporation. To enhance the effects of heat transfer to wastes, ferrous powder has been added into the graphite crucible, which aggregates as ingot below the molten silicate after vitrification. The slag fails to form glass if the quenching rate is less than 1 K/min. Therefore, the slag will break into small chips due to the sharp quenching rate, which is more than 100 K/sec.

Temporal characteristic simulation for stimulated emission depletion microscopy

The imaging technology of stimulated emission depletion (STED) utilizes the nonlinearity relationship between the fluorescence saturation and the excited state stimulated depletion. It implements three-dimensional (3D) imaging and breaks the diffraction barrier of far-field light microscopy by restricting fluorescent molecules at a sub-diffraction spot. In order to improve the resolution which attained by this technology, the computer simulation on temporal behavior of population probabilities of the sample was made in this paper, and the optimized parameters such as intensity, duration and delay time of the STED pulse were given.

Intensity-modulating characteristics of a laser diode subjected to optical injection

We have found that the optical power of a laser diode (LD) does not change with the injected light intensity that is modulated when its injection current is at some specific values. The amplitude of optical power change of the LD varies periodically with the increase of the injection current. It is made clear through theoretical analysis that these phenomena are caused by gain compression and interband carrier absorption of the LD that depend on longitudinal mode competition, bandgap-shrinkage effects, thermal conduction, and so on. Our experimental results make it easy to eliminate optical power change of LDs. We only need to choose a proper value of the injection current. (c) 2005 Optical Society of America.

Ti：Al2O3透明多晶陶瓷光谱特性分析

采用传统无压烧结工艺制备出透明性良好的掺Ti氧化铝陶瓷；测定了该陶瓷的吸收光谱、荧光光谱和激发光谱。结果表明，掺Ti氧化铝透明陶瓷样品在Mg与Ti掺入离子的摩尔比（NMg／NTi）较小时，表现出Ti^3＋离子的490nm特征吸收峰，即^2T2→^2E跃迁产生的宽带吸收；NMg／NTi较大时，陶瓷样品吸收光谱中不存在Ti^3＋离子吸收，其250nm处吸收为O^2-→Ti^4＋的转移吸收。掺Ti氧化铝透明陶瓷样品Ti^3＋离子的发射谱线与单晶的相吻合，同时Ti^3＋在氧化铝陶瓷中分布很均匀，且Ti^3＋浓度较

Effects of gamma-irradiation and air annealing on Yb-doped Y3Al5O12 single crystal

The effects of gamma-irradiation on the air-annealed 10 at.% Yb:Y3Al5O12 (YAG) and air annealing on the gamma-irradiated 10at.% Yb:YAG have been studied by the difference absorption spectra before and after treatment. The gamma-irradiation and air annealing led to opposite changes of the absorption properties of the Yb:YAG crystal. After air annealing, the gamma-irradiation induced centers were totally removed and the concentration of Fe3+ and Yb3+ were lightly increased. For the first time, the gamma-irradiation induced valence changes between Yb3+ and Yb2+ ions in Yb:YAG crystals have been observed. (C) 2007 Elsevier B.V. All rights reserved.

Study of thin-film SO2 gas sensors by photometric and ellipsometric methods

Pt-, Pd-, and Zr-doped SnO2 thin films and dopant-free VOx films were fabricated by planar magnetron sputtering. Tests for sensitivity to SO2 for all samples were conducted at 180 degreesC, and the sensitivities were investigated ex situ with photometric and ellipsometric methods at room temperature. It was found that the optical sensitivities as well as the sensitive wavelength region for SnO2 films could be tuned by doping. The Pd-doped SnO2 films had good sensitivity in the visible range, and the Zr-doped in the near IR. The dominant sensitive wavelength region for VOx films fell into the visible range, and the ratio of the sensitivity in the visible to that in the near IR increased with O-2/Ar in the depositing atmosphere. (C) 2001 society of Photo-Optical instrumentation Engineers .

山东山旺中新世古气候的定量研究

本论文研究的创新之处是在高分辨率的地层层序上选定3米X3米的工作剖面，逐层采集标本，定量研究山旺中新世古气候的变化过程。主要有以下新的认识和结论： 植物化石的数量和种类在地层层序上的变化很大。第5层、第6层、第7层、第13层、第15层和第16层的标本丰富，可以进行CLAMP分析。 第5层、第6层和第7层的泥岩中保存有丰富的植物化石，运用荧光显微分析技术可以清晰地观察到泥岩中植物的气孔和表皮细胞形态。 山旺地区中新世年均温（MAT）在9.5℃和11.3℃之间。较热月份平均温度（WMMT）在19.9 ℃和22.4 ℃之间。生长季月数（GSL）为5.9－－6.9个月。生长季节平均降水量（MGSP）为860－－1770 mm。生长季月平均降水量（MMGSP）为152－－253mm，生长季三个连续最湿的月份降水量（3－WET）为530－－920mm，三个连续最旱的月份的降水量（3－DRY）为286－－687mm。相对湿度（Rel. Hum）在73％以上，高达80％。特殊湿度（q-Specific Humidity）在5.9－－6.7之间，热熵值（H－Enthalpy）为298.5－－304.5。 气候参数在地层层序上存在变化。CLAMP分析的结论与最近亲缘种分析（NLR）的结论相似。CLAMP分析的年均温比现在山旺的年均温12.5℃低，比同层的线性分析结果低3℃。与海底有孔虫氧同位素的研究结论一致。山东山旺中新世古气候的研究可以作为中中新世全球气候变化研究的一个标尺。

绣球族的系统学研究

绣球科绣球族包含9属：草绣球属、叉叶蓝属、Broussaisia、常山属、绣球属、蛛网萼属、赤壁木属、冠盖藤属和钻地风属。到目前为止，绣球族内的属间关系还不清楚，族内的系统发育关系还有争论。本研究的目的是在前人研究的基础上，进一步发现新的系统学性状，为绣球族乃至绣球科补充新的证据;并综合多学科的研究结果进行分析，探讨绣球族的系统学关系。 本文研究了绣球族的外部形态学、花发育形态学、解剖学、分子系统学和分支系统学。 主要内容包括： 1. 形态学 通过标本室研究和野外观察，对绣球族植物的形态分化进行了分析。发现习性、地上茎的生存期限、花冠卷叠式、花瓣联合与否、花柱的联合程度、雄蕊的数目及排列具有系统学价值;放射花和果实是很好的分类性状，但并非可靠的系统学性状。 2. 花发育形态学 在扫描电子显微镜下，研究了绣球族常山属、绣球属、冠盖藤属、蛛网萼属共4种植物花器官发生和发育的全过程。发现它们的花萼均为螺旋式相继发生，花瓣的发生近乎同时。冠盖藤、马桑绣球及常山具两轮雄蕊，第一轮雄蕊发生于花瓣内轮正对萼片中部的位置，随后第二轮雄蕊发生于正对花瓣中部的位置。在第一轮雄蕊略靠内的位置形成第二轮雄蕊的时候，多数情况下，相邻的对萼雄蕊之间只形成1个对瓣雄蕊，但有时却形成2个对瓣雄蕊，使雄蕊群的数目略多于花被的数目。对萼雄蕊与对瓣雄蕊的分化方式基本一致，但它们在花芽中空间取向不同。 蛛网萼雄蕊数目极多，雄蕊群的发生式样较为独特，并不始于对萼三联体。最早的雄蕊于杯状体近基部发生，之后雄蕊的发生大致沿杯状体壁向上，具离心趋势。在雄蕊发生过程中杯状体继续伸长，为众多雄蕊的发生提供了空间。蛛网萼雌蕊的发生明显早于雄蕊，其它3种植物雌蕊的发生晚于雄蕊。4种植物的雌蕊在发生上较为相似，发育却不同。在常山、马桑绣球和蛛网萼中，花柱从开始到发育成熟始终分离，柱头在每个花柱的顶端形成;而冠盖藤属的花柱裂片从开始就是联合的，最终形成单一的花柱，柱头从合生花柱顶端远轴面分化形成。 3. 解剖学 在光学显微镜和扫描电子显微镜下，观察了绣球族9属42种1变种及近缘8属11种共53种1变种的叶表皮特征。发现气孔的分布、气孔器的类型、表皮细胞的形状及其垂周壁式样、毛被等具有一定的系统学意义和分类价值。绣球族各属的气孔仅散生于下表皮;而在绣球族的几个近缘属中，上下表皮均有气孔分布。气孔器在多数类群中为无规则型，仅常山属和绣球属离瓣组的成员为平列型。气孔多为椭圆形，稀近圆形;外拱盖表面通常光滑，仅在钻地风属中具条状纹饰;外拱盖内缘具环状加厚，近全缘、不规则波状或浅波状。表皮细胞在多数种中为不规则形，垂周壁波状、浅波状或深波状;在有些种中为（近）多边形，垂周壁平直或弓形。叶表皮细胞形状、垂周壁式样在绣球族寡种属属级水平比较稳定，但在绣球属中变化较大。表皮角质膜纹饰形态多样，有网纹、粗网纹、浅波状条纹、波状条纹、条纹、粗条纹及丝状条纹;在钻地风属及绣球属的少数种中，角质膜条纹有时汇集呈球形或玫瑰型。表皮毛状附属物有单细胞2分枝毛（黄山梅属）、多细胞星状毛（星毛冠盖藤）、单细胞星状毛（溲疏属）和单细胞不分枝毛四种。对钻地风属所有种的观察结果表明，仅在椭圆钻地风的下表皮细胞中央观察到乳突状结构，而在白背钻地风和圆叶钻地风中并未观察到前人描述的附属物。 4. 叶绿体DNA trnL-F序列的分析 首次对绣球族9属23种及近缘类群3属3种的trnL-F序列进行了测定。序列长度在860 bp~970 bp范围内变化。在以山梅花属、溲疏属和黄山梅属为外类群，基于trnL-F序列构建的系统树上，绣球族作为一个单系群得到很高的支持率。绣球属的种出现在不同的分支上，表明该属不是一个单系群。绣球族被分为两大支：第一支由绣球属离瓣组的中国绣球、绣球、以及常山和Broussaisia arguta组成;第二支由绣球属另外的9个种与草绣球属、叉叶蓝属、蛛网萼属、赤壁木属、冠盖藤属以及钻地风属组成。在第二支中，下列类群的近缘关系得到支持：① 草绣球与叉叶蓝属;② 绣球属挂苦子组的东陵绣球、圆锥绣球和挂苦绣球。③ 钻地风属、赤壁木属和冠盖藤属;④ 蜡莲绣球、莼兰绣球、马桑绣球、粗枝绣球。 5. 分支分析 以山梅花属为外类群，基于形态、解剖、花发育、孢粉等32个性状（或性状状态）对绣球族9属的系统发育关系进行了分支分析。结果表明：草绣球属和叉叶蓝属为基出类群，这两个属有多个共同特征;绣球族其余的成员聚成一支，该支又有5个分支。其中蛛网萼属和绣球属冠盖组各为单独的分支，它们有多个自衍征，可能有各自独立的演化线;绣球属离瓣组与常山属聚成一分支，二者的密切关系得到解剖学证据的支持;绣球属绣球组和星毛组聚成一分支，这两个组包含了绣球属的多数种类;钻地风属、赤壁木属、冠盖藤属、Broussaisia和绣球属挂苦子组聚成一分支。其中钻地风属、赤壁木属与冠盖藤属具多个近裔衍征，表明它们是绣球族的晚出类群。 通过对绣球族植物外部形态、花器官发生、叶表皮微形态特征、叶绿体DNA trnL-F区的研究以及基于形态性状的分支分析，并综合已有的研究结果，我们认为： 1. 绣球族是一个单系群;绣球属不是一个单系群。 2. 在绣球族中，草绣球属和叉叶蓝属关系密切，它们可能是绣球族其余成员的姐妹群。 3. 绣球组和星毛组可能是绣球属的核心成员;离瓣组和常山属关系密切;冠盖组有单独的演化线。 4. 赤壁木属、冠盖藤属和钻地风属为单系群，它们在绣球族处于较高的演化位置。 5. 绣球属需重新界定。