轻集料混凝土多孔砖砌体基本力学性能试验研究

对在夏热冬冷地区应用达到自保温体系要求的轻集料混凝土多孔砖砌体的基本力学性能进行试验研究,并通过试验分析了块体高度、试件厚度及砌筑形式对砌体抗压强度的影响.试验结果表明,此种自保温墙材可应用于承重结构.     

Properties and Stability of Solid Lipid Particle Dispersions Based on Canola Stearin and Poloxamer 188

Solid lipid particles (SLP) are one strategy for encapsulating lipophilic molecules, including for controlled release and enhanced bioavailability applications. SLP based on fully hydrogenated canola stearin (CaSt, 5, 10, 20, and 30 wt%) and the non-ionic surfactant Poloxamer 188 (P188, 0.0, 0.5, 1.0, 2.5, 5.0 and 10.0 wt%) were produced by high pressure melt homogenization using a microfluidizer. Spherical particles in the region of 140 nm were formed, depending on compostion and processing parameters. Surfactant concentration and pressure had a significant influence on particle diameter (P < 0.05), although number of homogenization cycles did not (P > 0.05). A maximum surfactant surface load of approximately 4 mg m⁻² was observed and, at or above 2.5% P188, excess surfactant was present in the continuous phase after production. P188 had the effect of decreasing particle size and facilitating transitions from the α to the β polymorph (P < 0.05) both through surface nucleation and size reduction effects. A stability study of the 10% CaSt SLP with 0.0, 1.0, or 5.0% P188 revealed particle growth for the 0.0 and 1.0% P188 SLP, especially at 20 versus 4 °C, but no changes in the 5.0% P188 SLP, which were exclusively in the β form, at both temperatures for up to 240 days.     

Monte Carlo Simulation of Massive Absorbers for Cryogenic Calorimeters

There is a growing interest in cryogenic calorimeters with macroscopic absorbers for applications such as dark matter direct detection and rare event search experiments. The physics of energy transport in calorimeters with absorber masses exceeding several grams is made complex by the anisotropic nature of the absorber crystals as well as the changing mean free paths as phonons decay to progressively lower energies. We present a Monte Carlo model capable of simulating anisotropic phonon transport in cryogenic crystals. We have initiated the validation process and discuss the level of agreement between our simulation and experimental results reported in the literature, focusing on heat pulse propagation in germanium. The simulation framework is implemented using Geant4, a toolkit originally developed for high-energy physics Monte Carlo simulations. Geant4 has also been used for nuclear and accelerator physics, and applications in medical and space sciences. We believe that our current work may open up new avenues for applications in material science and condensed matter physics.     

Prediction of Bulk Moduli and Pressure-Volume-Temperature Data for Petroleum Oils

The increasing use of complex hydraulic systems has resulted in an increasing demand for bulk modulus data. Reliable data are difficult and expensive to obtain. The isothermal secant and tangent bulk moduli of petroleum oils and pure hydrocarbons have been studied in detail. Generalizations of the relationships were achieved. Charts are given to enable prediction of these moduli and densities from 0 to 500 F, over a pressure range of more than 100,000 psi with a minimum of calculation. The average error is less than 1.0%. The only required data are the density of the oil at atmospheric pressure and the desired temperature. Oil type or viscosity does not affect the result.     

Construction of measures from many-facet data

An extension to the Rasch model for fundamental measurement is described in which there is parameterization not only for examinee ability and item difficulty but also for judge severity. Variants of this model are discussed and judging plans reviewed. Its use and characteristics are explained by an application of the model to an empirical testing situation. A comparison with Generalizability Theory using a common data set is presented as a contrast in approaches to resolving judge indeterminacy.     

Remote monitoring of the earthquake cycle using satellite radar interferometry

The earthquake cycle is poorly understood. Earthquakes continue to occur on previously unrecognized faults. Earthquake prediction seems impossible. These remain the facts despite nearly 100 years of intensive study since the earthquake cycle was first conceptualized. Using data acquired from satellites in orbit 800 km above the Earth, a new technique, radar interferometry (InSAR), has the potential to solve these problems. For the first time, detailed maps of the warping of the Earth's surface during the earthquake cycle can be obtained with a spatial resolution of a few tens of metres and a precision of a few millimetres. InSAR does not need equipment on the ground or expensive field campaigns, so it can gather crucial data on earthquakes and the seismic cycle from some of the remotest areas of the planet. In this article, I review some of the remarkable observations of the earthquake cycle already made using radar interferometry and speculate on breakthroughs that are tantalizingly close.     

Bacteriorhodopsin crystal growth in reduced gravity - Results under the conditions,given in CPCF on board of a space shuttle,versus the conditions,given in DCAM on board of the Space Station Mir

For the purpose of bio-electronics, bacteriorhodopsin was crystallized into two habits through liquid-liquid-diffusion, namely individual needles of up to 1.9 mm in length and needle bunch-like clusters of up to 4.9 mm in total length. In both the reduced gravity experiments performed, the morphology of the individual needles (crystal form A) had improved in terms of sharp needle edges and compact needle packing, compared to the parallel ground controls. For the long duration wide range low gravity condition in the "Diffusion-controlled Crystallization Apparatus for Microgravity (DCAM)" on Mir (STS-89 up), needle bunches on average were longer there than on the ground, while the compactness of the clusters, i.e. the average ratio of clustered length to clustered width was the reverse. Some exceptionally large individual needles were grown in DCAM. For the "Commercial Protein Crystallization Facility (CPCF)" in short duration high definition microgravity condition during a science mission of the Space Shuttle Discovery (STS-95), size and shape of the individual needles were homogeneous and superior to those of both the parallel ground controls and the results in DCAM. In CPCF, the average volume of the individual needles in suspension was increased by 50 % in microgravity compared to those in the ground control.     

Linking learning goals and educational resources through interactive concept map visualizations

Concept browsing interfaces can help educators and learners to locate and use learning resources that are aligned with recognized learning goals. The Strand Map Service enables users to navigate interactive visualizations of related learning goals and to request digital library resources aligned with learning goals. These interfaces are created using a programmatic Web service interface that dynamically generates interactive visual components. Preliminary findings suggest that these library interfaces appear to help users stay focused on the scientific content of their information discovery task, as opposed to focusing on the mechanics of searching.     

Accessing the spoken word

Spoken-word audio collections cover many domains, including radio and television broadcasts, oral narratives, governmental proceedings, lectures, and telephone conversations. The collection, access, and preservation of such data is stimulated by political, economic, cultural, and educational needs. This paper outlines the major issues in the field, reviews the current state of technology, examines the rapidly changing policy issues relating to privacy and copyright, and presents issues relating to the collection and preservation of spoken audio content .