Archeological optics: the very first known mirrors and lenses

The primary objective of the paper is to review histories of early known mirrors and lenses. Squinting/pinholes/slit apertures provided initial visual enhancements; quiet pools of water served as early mirrors. Manufactured mirrors appeared during the Stone Age 8000 years ago in Çatal Höyük in Anatolia within modern Turkey. The next generation mirrors were Mesopotamian and Egyptian. Oldest lenses, extraordinary in quality and complexity with built-in illusion, were in use in Egypt 4575 years ago. Simpler lens forms appeared between 3932(?)–3500 years ago, probably in the Levant/Eastern Mediterranean basin. The main outcomes are: (1) civilized societies had mirrors by about 4000 years ago, including China, India (e.g. Lothal) and New World societies. (2) Siberia and China had different mirror designs than Western areas. (3) Only crystalline materials were used in New World mirrors. (4) The author located an Egyptian lens in Boston having original lens design, this extended this lens' utilization by ca. 800 years to 3070–2656 years ago. These histories are fascinating!     

Microstructure,Hardness, and Wear Assessment of Spark-Plasma-Sintered Ti-xAl-1Mo Alloy

Metallurgical and Materials Transactions A - Alloys from the Ti-Al-Mo ternary system are of high importance in aerospace applications due to their excellent specific strength-to-density ratio,...     

Second-harmonic specular and scattered generated light: application to the experimental study of zinc-sulfide thin films

We present measurements of second-harmonic generation with zinc-sulfide thin films. Both scattered light and specular light are investigated in linear optics as well as in second-harmonic generation. We show that second-harmonic generation is a powerful tool for understanding the nonlinear properties of thin films; it allows the study of the anisotropy found in the scattered and specular second harmonic. Using the symmetry of susceptibility tensors, we show that the films cannot be considered homogeneous when the crystallites are large. Finally, we outline nonlinear scattering measurements, which bring out the usefulness of second-harmonic light in probing the structure of thin films.     

轻松修改BIOS，提升显卡性能 800SP 4830完美变身4850

毫无疑问,目前800个流处理器（800SP）的RadeonHD4830显卡深受玩家追捧．除了设备ID和频率以外．它的主要硬件规格和RadeonHD4850显卡非常相似。那么有没有方法让RadeonHD4830的频率和设备ID完全和RadeonHD4850显卡保持一致．即将RadeonHD4830完美改造成RadeonHD4850呢？     

Estradiol Protects against Noise-Induced Hearing Loss and Modulates Auditory Physiology in Female Mice

Recent studies have identified sex-differences in auditory physiology and in the susceptibility to noise-induced hearing loss (NIHL). We hypothesize that 17β-estradiol (E₂), a known modulator of auditory physiology, may underpin sex-differences in the response to noise trauma. Here, we gonadectomized B6CBAF1/J mice and used a combination of electrophysiological and histological techniques to study the effects of estrogen replacement on peripheral auditory physiology in the absence of noise exposure and on protection from NIHL. Functional analysis of auditory physiology in gonadectomized female mice revealed that E₂-treatment modulated the peripheral response to sound in the absence of changes to the endocochlear potential compared to vehicle-treatment. E₂-replacement in gonadectomized female mice protected against hearing loss following permanent threshold shift (PTS)- and temporary threshold shift (TTS)-inducing noise exposures. Histological analysis of the cochlear tissue revealed that E₂-replacement mitigated outer hair cell loss and cochlear synaptopathy following noise exposure compared to vehicle-treatment. Lastly, using fluorescent in situ hybridization, we demonstrate co-localization of estrogen receptor-2 with type-1C, high threshold spiral ganglion neurons, suggesting that the observed protection from cochlear synaptopathy may occur through E₂-mediated preservation of these neurons. Taken together, these data indicate the estrogen signaling pathways may be harnessed for the prevention and treatment of NIHL.     

洗牌在即DirectX 11显卡市场现状分析

一直以来,DirectX11显卡市场都是AMD在唱主角。虽然NVIDIA发布了GeForce GTX 480／470产品,但由于定位于高端,并未对市场销售造成实质的影响。随着GeForceGTX460．GeForceGTS 450产品的发布,DirectX11显卡市场风云突变。市场格局洗盘在即。     

Investigation of Extracting Photonic Crystal Lattices for Guided Modes of GaAs-Based Heterostructures

The issue of extracting guided modes from a standard light-emitting heterostructure similar to those of visible or near-infrared light-emitting diodes is considered with respect to the role of lattices and of the amount of omnidirectionality in the extraction performances. Triangular lattices are first-order natural candidates. We examine first whether they can be made omnidirectional thanks to a grating + coupler combination initially proposed by Fehrembach et al (2001), whereby the short periodicity concentrates emission in few in-plane modes, and the double periodicity extracts it. We then examine lattices that directly extract, for a Ga(Al)As system on a GaAs substrate, with a specific 3-D mode decay calculation. We compare triangular and Archimedean lattices experimentally and point out the role of photonic strength also through a spectrally and angularly resolved experiment.     

Dynamic generalized fast initial response for EWMA control schemes for monitoring processes with startup and post-startup problems

The exponentially weighted moving average (EWMA) control schemes have been proven to be very effective at monitoring random shifts or disturbances in a given process. However, EWMA is somewhat insensitive to the shifts at the process startup. Consequently, fast initial response feature (FIR) or headstart has often been used to increase the sensitivity of EWMA at the process startup. Although FIR feature significantly increases the sensitivity of the EWMA at the startup, its effects diminished after few observations thereby making FIR-based schemes less sensitive compared to the classical EWMA at the process post-startup. In this paper, we proposed the dynamic generalized fast initial response for the EWMA control schemes for monitoring processes with startup and post-startup problems. The proposed scheme is highly sensitive at the startup and has a sensitivity equal to that of the classical EWMA at the process post-startup. The average run length based performance comparisons of the proposed chart and its counterparts are presented. Real-life examples are offered to demonstrate the applications of the proposed scheme.