Illumination with solid state lighting technology

High-power light-emitting diodes (LEDs) have begun to differentiate themselves from their more common cousins the indicator LED. Today these LEDs are designed to generate 10-100 lm per LED with efficiencies that surpass incandescent and halogen bulbs. After a summary of the motivation for the development of the high-power LED and a look at the future markets, we describe the current state of high-power LED technology and the challenges that lay ahead for development of a true "solid state lamp." We demonstrate record performance and reliability for high-power colored and white LEDs and show results from the worlds first 100-plus lumen white LED lamp, the solid state equivalent of Thomas Edison's 20-W incandescent lightbulb approximately one century later     

芝麻油掺伪通用检验方法研究

在系统调查国内流通领域几种主要油脂脂肪酸组成的基础上，对芝麻油掺入其它油品质后脂肪酸组成变化规律进行了详细研究，找出了芝麻油掺伪检验的定性定量依据。     

A flexible graphical user interface for embedding heterogeneousneural network simulators

A graphical user interface (GUI) for heterogeneous neural network simulators proposed in this article is intended to be of use both for the novice and for the experienced neural network user. For the novice, it provides an easy-to-use neural network simulation package that insulates the user from the requirements of knowing the simulator implementation details or the configuration file syntax. For the experienced neural network professional it provides an interface that is easily extensible to include any additional neural network simulator in its binary form. To satisfy both academic and personal computer environments, the GUI has been developed by using the free TCL/TK software package, available on workstations running Unix and on PCs running the free Linux operating system. Although the GUI and the embedded simulators have been successfully tested both in neural network research and training programs, a more extensive testing in undergraduate and graduate level classes is in progress     

Arcjet flow properties determined from laser-induced fluorescence of atomic nitrogen

Flow property measurements that were recently acquired in the Ames Research Center Aerodynamic Heating Facility arcjet using two-photon laser-induced fluorescence (LIF) of atomic nitrogen (N) are reported. The flow properties, which include velocity, translational temperature, and N concentration, were measured simultaneously over a range of facility operating conditions for N(2)-argon test gas flows in the 30-cm-diameter nozzle. A recent measurement of the two-photon excitation cross section for the 3p(4)D degrees <-- 2p(4)S degrees transition of atomic nitrogen is used to convert the relative nitrogen concentration measurements to absolute values, and a nitrogen flow reactor is used to provide a room-temperature, reference-wavelength calibration of the translational temperature and velocity measurements. When combined with information from facility measurements, an analysis of the flow properties obtained using two-photon LIF of N yields the total free-stream flow enthalpy.     

The inverted repeat regions of the simian varicella virus and varicella-zoster virus genomes have a similar genetic organization

Simian varicella virus (SVV) causes a varicella-like disease in nonhuman primates. The DNA sequence and genetic organization of the inverted repeat region (RS) of the SVV genome was determined. The SVV RS is 7559 bp in size with 56% guanine+cytosine (G+C) content and includes 3 open reading frames (ORFs). The SVV RS1 ORF encodes a 1279 amino acid (aa) protein with 58 and 39% identity to the varicella-zoster virus (VZV) gene 62 and herpes simplex virus type 1 (HSV-1) ICP4 homologs, respectively. The predicted 261 aa SVV RS2 polypeptide possesses 52% identity with the VZV gene 63 homolog and 23% identity with the HSV-1 ICP22. The SVV RS3 encodes a 187 aa polypeptide with 56% and 28% identity to the VZV gene 64 and the HSV-1 US10 homologs, respectively, and includes an atypical zinc finger motif. A G+C-rich 16 base-pair (bp) sequence which is repeated 7 times and a putative SVV origin of replication were identified between the RS1 and RS2 ORFs. Comparison with the VZV RS indicates the SVV and VZV RS regions are similar in size and genetic organization.     

The relative efficacy of avoidant and nonavoidant coping strategies: A meta-analysis.

Conducted a series of meta-analyses, involving 43 studies, to ascertain whether there were systematic patterns in the empirical literature that described when attention strategies were more or less effective than avoidant strategies. Results of an overall analysis of studies providing tests of attention vs avoidance indicated little evidence for one strategy's superiority. However, supplementary analyses suggested there were boundary conditions that defined the relative efficacy of a specific strategy. Overall, avoidance was associated with more positive adaptation in the short-run. However, attention was superior to avoidance if the former involved a focus on sensory schemata rather than emotional processing. If attention involved an emotional interpretational set or no explicit set, then it was associated with more negative outcomes than avoidance. In terms of long-term outcomes, avoidance indicated better outcomes initially, but with time, attention was associated with more positive outcomes. A final set of analyses found that both attention and avoidance facilitated adaptation as compared with no instruction controls. The meta-analyses suggested the important role of interpretational set and whether one looks at the immediate or at the long-term effects of coping. (5 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Dorodnitsyn finite element formulation for turbulent boundary layers

The Dorodnitsyn boundary layer formulation is combined with a modified Galerkin finite element formulation and an implicit, non-iterative marching scheme to generate a computational algorithm that is both accurate and very economical. For four representative pressure gradient cases taken from the 1968 Stanford Turbulent Boundary Layer Conference the Dorodnitsyn finite element formulation is compared with a Dorodnitsyn spectral formulation and a representative finite difference package. All methods produce solutions of high accuracy but the Dorodnitsyn finite element formulation is about ten times more economical than the other methods.     

Hydrogen and oxygen from water—III evaluation of a hybrid process

A hybrid process, which simultaneously produces mechanical power and hydrogen and oxygen from water by the use of solar energy, is presented. The performance of the process is evaluated. Realistic constraints on the efficiencies of optical and mechanical components are used. A preliminary estimate of its economics is also presented.     

Temperature dependence of the strength-differential effect in hardened steels

The strength differential (SD) has been measured as a function of temperature in a fully hardened 0.2C, 6 Ni steel, quenched and then tempered at 250°C. It is found appropriate to express the results in terms of the intercept flow stresses as extrapolated back to zero plastic strain. The corresponding SD increases significantly with decreasing temperature below the ambient, and the data are well fitted by separating the SD into an athermal component (~3 pct) and a thermally activated component (up to ~15 pct at the liquid-nitrogen temperature). The latter type of contribution is thought to arise from a dilatation which occurs during the activation process for dislocation motion and which causes an increase in the activation energy under compressive loading and a decrease under tensile loading. The parameters obtained via this treatment are consistent with a double-kink Peierlsbarrier mechanism of plastic flow at low temperatures. This paper is based on a doctoral thesis presented in August 1972 by F. B. Fletcher to the Department of Metallurgy and Materials Science at the Massachusetts Institute of Technology.