Weld microstructure refinement in a 1441 grade aluminium-lithium alloy

Clad 2 mm thick sheets of Russian 1441 grade Al-Li alloys were welded using a gas tungsten arc welding process (GTAW). Comparisons were made between the weld beads obtained under (i) continuous current (CC), (ii) pulsed current (PC), and (iii) arc oscillation (AO) conditions for their macro- and microstructural details. In the case of CC GTAW, sound welds could be produced only under a narrow range of welding parameters. Centre line cracks, which occurred in CC GTAW welds under certain conditions, were halted by switching to PC or AO conditions while the welding was in progress. Microstructural refinement was significant in the case of PC and AO GTA welding. This revised version was published online in November 2006 with corrections to the Cover Date.     

Novel hybrid solar cells based on α-copper phthalocyanine–cadmium sulfide planar heterojunction

Cadmium sulfide (CdS) has been employed as an alternative acceptor for planar heterojunction solar cell based on copper phthalocyanine (CuPc). Spin-coated poly-3,4-ethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS) on indium tin oxide (ITO)-coated glass substrates was used for the vacuum deposition of CuPc and CdS planar heterojunction. In the present study, we have fabricated two different architectures of CuPc/CdS devices: (1) ITO/PEDOT:PSS/CuPc/CdS/Al and (2) ITO/PEDOT:PSS/CuPc/CdS/LiF/Al. Our results indicate that the CdS could effectively facilitate charge transport in the nanostructured network, and be a good acceptor. The fabricated bare CuPc/CdS device shows 0.13 % conversion efficiency while incorporation of LiF layer between CuPc/CdS and Al contact facilitates low-recombination rate results ~43 % enhancement in efficiency. The ITO/PEDOT:PSS/CuPc/CdS/LiF/Al device shows 0.30 % power conversion efficiency.     

Novel synthesis of interconnected nanocubic PbS thin films by facile aqueous chemical route

In the present investigation, we have successfully synthesized lead sulfide (PbS) thin films by using simple, cost effective and facile aqueous chemical route. The effect of deposition time on optical, structural and morphological properties of PbS thin films were investigated by using UV–Vis–NIR absorption spectroscopy, X-ray diffraction (XRD), photoluminescence, field emission scanning electron microscopy (FESEM), high-resolution-transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The optical band gap energy was varied in the range of 0.96–1.56 eV. The XRD patterns revealed the formation of pure cubic crystal structure. FESEM micrographs demonstrated the conversion of morphology from pyramidal to interconnected nanocubic. HRTEM and selected area electron diffraction (SAED) pattern illustrated that nanoparticles are compact, well interconnected and single crystalline in nature. EDS spectrum confirms that deposited PbS thin films are in good stoichiometry.     

日本当代前卫艺术家村上隆作品探析

日本当代前卫艺术家村上隆在继承日本传统文化的基础上,模仿与借鉴西方文化,在他的作品中东方传统与西方文明达到了完美融合.在日益浮躁的现代社会中,艺术趋媚于大众趣味,村上隆将精英文化融入通俗文化创作中,为通俗文化与高雅艺术的结合找到了沟通的桥梁.同时,在艺术作品被认为必须崇高与纯粹的时候,村上隆则以商业态度进行艺术创作,实现了艺术创作与商业时尚的交集.     

Distributed topology management for wireless multimedia sensor networks: exploiting connectivity and cooperation

In this paper, we propose a distributed topology management algorithm, named T‐Must, which orchestrates coalition formation game between camera and scalar sensor (SS) nodes, for use in wireless multimedia sensor networks. In the proposed solution, connectivity among the peer camera sensor (CS) nodes is maintained, and coverage is ensured between them. Only the scalar data are not sufficient to describe an event in a particular monitored area. In many cases, multimedia data (specifically, video data) are required to provide more precise information about the event. As the CS nodes, which sense and transmit multimedia data, are costlier than the SS nodes, the former are deployed in the monitored area in lesser numbers compared to the latter ones. In case of CS nodes, power consumption due to sensing is also significant, similar to power consumption for the transmission and reception of packets. Therefore, in this work, in order to increase the network lifetime, topology is controlled by forming coalition between the CS and SS nodes. Upon occurrence of an event, the SS nodes send scalar data to their associated CS nodes. If the scalar data received from SS nodes cross a preconfigured threshold, the associated CS node in the coalition starts sensing the event, captures the video data, and forwards the video data toward other coalitions or sink. Copyright © 2014 John Wiley & Sons, Ltd.     

车床夹具的平衡设计

介绍了一种车夹具,对车夹具中各元件质量所产生的力进行了静平衡计算,消除了因惯性力而产生的机械振动。使用后表明,该夹具操作方便,安全可靠,效率大大提高。     

Low temperature aqueous chemical synthesis of CdS sensitized ZnO nanorods

Cadmium sulfide nanoparticles (CNPs) sensitized zinc oxide nanorod arrays (ZNRs) were synthesized in the two step deposition process at relatively low temperature. The vertically aligned ZNRs were grown on the conducting glass substrates (FTO) using aqueous chemical method, followed by the deposition of CNPs at 70 °C using chemical bath deposition (CBD) technique. The samples were characterized by optical absorption, X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL). Further, the photoelectrochemical (PEC) performance of ZNRs with and without CNPs sensitization was tested in Na₂S-NaOH-S and Na₂SO₄ electrolyte, respectively. When the CNPs are coated on the ZNRs, the optical absorption is enhanced and band edge is shifted towards visible region (525 nm) as compared with ZNRs (375 nm). The sample sensitized with CNPs shows higher photoelectrochemical (PEC) performance with maximum short circuit current of (I_sc) 2.60 mA/cm².     

CTA-based angle selection for diagnostic and interventional angiography of saccular intracranial aneurysms

Coil embolization is a safe treatment for cerebral aneurysms only if the width of the neck in relation to the fundus of the aneurysm is small. Therefore, accurate visualization of the aneurysmal neck is required both in the diagnostic process and during the intervention. Conventional digital subtraction angiography (DSA) is still the preferred modality for the examination of cerebrovascular abnormalities like aneurysms, but it often does not provide the required morphological characteristics due to the suboptimal selection of projection angles and resulting overprojections of surrounding vasculature. This paper presents a method for performing a computer-assisted calculation of the optimal projection angles for DSA by post-processing computed tomographic angiography (CTA) volume data using ray-casting techniques and a combination of image processing algorithms. By means of phantom studies, retrospective simulations of angiograms, and in vivo applications of calculated optimal viewing angles, it is demonstrated that the proposed method results in better angiographic projections of the neck of saccular aneurysms with small neck-fundus ratio than those acquired at standard angles prescribed by clinical protocols.     

用厚透镜实现分数阶付里叶变换

本文给出了厚透镜实现分数阶付里变换的光学结构；定量分析了阊最透镜和双厚秀镜结构中分数付里叶变换和透镜参数之间的关系。计算表明用厚透镜可以实现分类阶付时变换。