一种分布式吴方法计算模型

吴方法是由我国科学家吴文俊院士开创的一个新兴研究领域.考虑到吴方法"分而治之"的思想非常适合分布式计算,将分布式计算技术引入到该方法的计算过程中,给出一种既可以在集群环境下,也可以在网格环境下实现的分布式吴方法计算框架.首先分析了吴方法分布式计算需求,并以特征列计算为例来说明吴方法分布式计算算法,然后讨论了符号计算基本数据类型:大整数和多项式的消息传递方法,最后简单给出了在网格环境下基于符号计算软件系统ELIMINO和网格中件间Globus Toolkits 3的分布式吴方法计算环境的设计、实现与实验结果.

The design and operation of a new clapboard-type internal circulating fluidized-bed gasifier

The design and operation of a new clapboard-type internal circulating fluidized-bed gasifier is proposed in this article. By arranging the clapboard in the bed, the gasifier is thus divided into two regions, which are characterized by different fluidization velocities. The bed structure is designed so that it can guide the circulating flow passing through the two regions, and therefore the feedstock particles entrained in the flow experience longer residence time. The experimental results based on the present new design, operating in the temperature range of 790 degrees C-850 degrees C, indicate that the gas yield is from 1.6-1.9 Nm(3)/kg feedstock, the gas enthalpies are 5,345 kJ/Nm(3) for wood chip and 4,875 kJ/m(3) for rice husk, and a gasification efficiency up to 75% can be obtained.

Experimental investigation of production behavior of methane hydrate under ethylene glycol injection in unconsolidated sediment

This article investigates the gas production behavior from methane hydrate (MH) in porous sediment by injecting ethylene glycol (EG) solution with the different concentrations and the different injection rates in an one-dimensional experimental apparatus. The results suggest that the gas production process can be divided into the four stages: (1) the initial injection, (2) the EG diluteness, (3) the hydrate dissociation, and (4) the remained gas output. Nevertheless, the water production rate keeps nearly constant during the whole production process. The production efficiency is affected by both the EG concentration and the EG injection rate, and it reaches a maximum with the EG concentration of 60 wt %.

Thermomechanical and Optical Properties of Biodegradable Poly(L-lactide)/Silica Nanocomposites by Melt Compounding

Poly(L-lactide) (PLA)/silica (SiO2) nanocomposites containing 1, 3, 5, 7, and 10 Wt % SiO2 nanoparticles were prepared by melt compounding in a Haake mixer. The phase morphology, thermomechanical properties, and optical transparency were investigated and compared to those of neat PLA. Scanning electron microscopy results show that the SiO2 nanoparticles were uniformly distributed in the PLA matrix for filler contents below 5 wt %, whereas some aggregates were detected with further increasing filler concentration. Differential scanning calorimetry analysis revealed that the addition Of SiO2 nanoparticles not only remarkably accelerated the crystallization speed but also largely improved the crystallinity of PLA. An initial increase followed by a decrease with higher filler loadings for the storage modulus and glass-transition temperature were observed according to dynamic mechanical analysis results. Hydrogen bonding interaction involving C=O of PLA with Si-OH Of SiO2 was evidenced by Fourier transform infrared analysis for the first time.

贵州喀斯特高原湖泊物质循环过程中的铜锌同位素地球化学－以红枫湖、阿哈湖为例

近年来铜、锌同位素地球化学研究已经进入了快速发展时期。作为新兴的同位素技术手段，铜锌同位素工具已普遍应用于地球化学、矿床学、古海洋学和生物学等多种领域，然而铜、锌同位素在湖泊生态系统中的研究却相对较少。湖泊生态系统中，重金属的迁移、循环与转化一直是地球科学家们关注的焦点，但研究手段仅局限于含量与形态的测定。因此本论文旨在通过对湖泊生态系统中铜、锌同位素的研究，揭示影响铜、锌同位素组成的主要因素，为铜、锌同位素成为湖泊系统中新的重金属示踪工具奠定基础。 本论文通过一系列条件实验，确定了用于MC-ICP-MS测定环境样品中铜、锌同位素时最佳的化学分离条件。随后选取红枫湖和阿哈湖为主要研究对象，用此实验流程对湖泊水体及其主要支流悬浮物中的铜、锌同位素的季节及剖面变化进行了初步研究。除此之外，对水体中重金属如Cu、Zn、Mn、Ni、Co、Cr、Cd和Pb的形态分布特征及物质循环进行了研究。主要得出以下几点认识： 1、环境样品中铜锌的最佳分离条件是，采用AG MP-1(100-200目)阴离子交换树脂，分别以7 mol/L HCl + 0.001% H2O2，2 mol/L HCl+ 0.001% H2O2，0.5 mol/L HNO3作为淋洗液，并分别在适当的体积接收淋洗液，可以有效地分离沉积物、植物和悬浮物等样品中的铜和锌。化学分离过程中回收率接近100％，同位素比值的变化均在误差范围以内。 2、红枫湖、阿哈湖水体及主要支流悬浮物和红枫湖生物样品中的δ65Cu分布范围为-2.64‰~1.11‰，可达到3.75‰的变化。红枫湖夏季水体悬浮物的δ65Cu变化为-0.08‰~0.25‰，入湖河流水体悬浮物δ65Cu的变化范围为0.13‰~ 1.11‰；阿哈湖夏季水体悬浮物δ65Cu的变化范围为-0.62‰~0.37‰，入湖河流水体悬浮物δ65Cu的变化范围为-1.08‰~0.60‰。两湖冬季水体悬浮物的δ65Cu值均较负。红枫湖生物样品中δ65Cu较负（-1.54‰~ 0.03‰）。 红枫湖水体悬浮物中δ65Cu的随水深的变化趋势主要受到藻类吸收作用的控制，而阿哈湖δ65Cu的随水深的变化趋势主要受到其物源的控制。说明在贫营养化湖泊中，铜同位素组成可以示踪物源；而在富营养化湖泊中，铜同位素组成则可以示踪生物活动。同时水温的垂直变化也可能是其影响因素之一。 3、红枫湖水体及其主要支流水体悬浮物中的δ66Zn变化范围分别为-0.29‰~0.26‰和-0.04‰~0.48‰，阿哈湖水体及其主要支流水体悬浮物中的δ66Zn变化范围分别为-0.18‰~0.27‰和-0.17‰~0.46‰，均表现出支流中的锌同位素组成较重的趋势。而生物样品中的δ66Zn变化范围较大，为-0.35‰~0.57‰。说明湖泊生态系统中各端元的锌同位素组成存在明显差异。 红枫湖夏季δ66Zn随着湖水深度的变化，与Chla（叶绿素）呈极显著的正相关(R=0.97)。说明锌同位素组成与藻类生物量有一定的响应关系，主要是藻类对锌的有机吸附或是吸收过程改变了锌同位素组成。阿哈湖的锌同位素组成主要受到其源区的控制作用，从而可利用锌同位素示踪源区；此外，红枫湖和阿哈湖悬浮物中的锌同位素比值均表现出夏季小于冬季，说明大气的干湿沉降可能是一个较负的锌同位素源。生物样品中的δ66Zn变化范围较大，说明由于生物作用过程导致的锌同位素分馏大于非生物过程。 4、红枫湖重金属Mn、Ni、Co、Cr、Cd和Pb的含量在南湖高于北湖，主要是羊昌湖的输入所导致；重金属入湖通量的季节性变化，直接导致了重金属含量的季节性变化。沉积物－水界面在冬夏季节，由于“富氧”和“贫氧”状态的改变，导致了溶解态Mn、Ni和Cr的季节性变化；水粒相互作用过程中，溶解有机碳（DOC）、氧化铁胶体、氧化锰胶体和水生藻类的生长繁殖，影响了重金属不同结合形态的变化。

Temperature and strain rate dependence of syntactic foam under tensile and shear loads

The behaviour of syntactic foam is strongly dependent on temperature and strain rate. This research focuses on the behaviour of syntactic foam made of epoxy and glass microballoons in the glassy, transition and rubbery regions. Both epoxy and epoxy foam are investigated separately under tension and shear loadings in order to study the strain rate and temperature effects. The results indicate that the strength and strain to failure data can be collapsed onto master curves depending on temperature reduced strain rate. The highest strain to failure occurs in the transition zone. The presence of glass microballoons reduces the strain to failure over the entire range considered, an effect that is particularly significant under tensile loading. However, as the microballoons increase the elastic modulus significantly in the rubbery zone but reduce it somewhat in the glassy zone, the effect on the strength is more complicated. Different failure mechanisms are identified over the temperature-frequency range considered. As the temperature reduced strain rate is decreased, the failure mechanism changes from microballoon fracture to matrix fracture and debonding between the matrix and microballoons. © IMechE 2012.

Multi-wavelength observations of Proxima Centauri

Aims: We report simultaneous observations of the nearby flare star Proxima Centauri with VLT/UVES and XMM-Newton over three nights in March 2009. Our optical and X-ray observations cover the star's quiescent state, as well as its flaring activity and allow us to probe the stellar atmospheric conditions from the photosphere into the chromosphere, and then the corona during its different activity stages. Methods: Using the X-ray data, we investigate variations in coronal densities and abundances and infer loop properties for an intermediate-sized flare. The optical data are used to investigate the magnetic field and its possible variability, to construct an emission line list for the chromosphere, and use certain emission lines to construct physical models of Proxima Centauri's chromosphere. Results: We report the discovery of a weak optical forbidden Fe xiii line at 3388 Å during the more active states of Proxima Centauri. For the intermediate flare, we find two secondary flare events that may originate in neighbouring loops, and discuss the line asymmetries observed during this flare in H i, He i, and Ca ii lines. The high time-resolution in the Hα line highlights strong temporal variations in the observed line asymmetries, which re-appear during a secondary flare event. We also present theoretical modelling with the stellar atmosphere code PHOENIX to construct flaring chromospheric models. Based on observations collected at the European Southern Observatory, Paranal, Chile, 082.D-0953A and on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member states and NASA.Full Table 6 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/534/A133

A influência das condições de cura nas propriedades das argamassas de cal para revestimentos antigos

Dissertação elaborada no Laboratório Nacional de Engenharia Civil (LNEC) para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Edificações no âmbito do protocolo de cooperação entre o ISEL e o LNEC

L'Écho de Paris

1893/08/27 (Numéro 3388).

Shui hua er da.

Double.

Resolución N° 46154 - SIC: Por la cual se resuelve un recurso de apelación

Servicios registrales

TIME COURSE OF SIGNALING PROCESSES INVOLVED WITH EXTRACELLULAR OSMOTIC - INDUCED GLUCOSE UPTAKE IN MAMMALIAN SKELETAL MUSCLE

Extracellular hyper-osmotic (HYPER) stress increases glucose uptake to defend cell volume, when compared to iso-osmotic (ISO) conditions in skeletal muscle. The purpose of this study was to determine a time course for changes in common signaling proteins involved in glucose uptake during acute hyper-osmotic stress in isolated mammalian skeletal muscle. Rat extensor digitorum longus (EDL) muscles were excised and incubated in a media formulated to mimic ISO (290 ± 10 mmol/kg) or HYPER (400 ± 10 mmol/kg) extracellular condition (Sigma Media-199). Signaling mechanisms were investigated by determining the phosphorylation states of Akt, AMPK, AS160, cPKC and ERK after 30, 45 and 60 minutes of incubation. AS160 was found to be significantly more phosphorylated in HYPER conditions compared to ISO after 30 minutes (p<0.01). It is speculated that AS160 phosphorylation increases glucose transporter 4 (GLUT4) content at the cell surface thereby facilitating an increase in glucose uptake under hyper-osmotic stress.