300,306 research outputs found
A new bound for the smallest x with ?(x) > li(x)
No full textWe reduce the leading term in Lehman's theorem. This improved estimate allows us to refine the main theorem of Bays and Hudson [2]. Entering 2,000,000 Riemann zeros, we prove that there exists x in the interval [exp (727.951858), exp (727.952178)] for which ?(x) - li(x) > 3.2 × 10151. There are at least 10154 successive integers x in this interval for which ?(x) > li(x). This interval is strictly a sub-interval of the interval in Bays and Hudson, and is narrower by a factor of about 12
Structural and electrochemical characterization of xLi[Li1/3Mn2/3]O2·(1 - x)Li[Ni1/3Mn1/3Co1/3]O2 (0 ≤ x ≤ 0.9) as cathode materials for lithium ion batteries
No full textA series of cathode materials with molecular notation of xLi[Li1/3Mn2/3]O2·(1 - x)Li[Ni1/3Mn1/3Co1/3]O2 (0 ≤ x ≤ 0.9) were synthesized by combination of co-precipitation and solid state calcination method. The prepared materials were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques, and their electrochemical performances were investigated. The results showed that sample 0.6Li[Li1/3Mn2/3]O2·0.4Li[Ni1/3Mn1/3Co1/3]O2 (x = 0.6) delivers the highest capacity and shows good capacity-retention, which delivers a capacity ∼250 mAh g-1 between 2.0 and 4.8 V at 18 mA g-1. © 2008 Elsevier B.V. All rights reserved
Assessment of Self-Archiving in Institutional Repositories: Depositorship and Full-Text Availability
No full textThis research evaluates the success of open access self-archiving in several well-known institutional repositories. Two assessment factors have been applied to examine the current practice of self-archiving: depositorship and the availability of full text. This research discovers that the rate of author self-archiving is low and that the majority of documents have been deposited by a librarian or administrative staff. Similarly, the rate of full-text availability is relatively low, except for Australian repositories. By identifying different practices of self-archiving, repository managers can create new strategies for the operation of their repositories and the development of archiving policies
Generalized Marshall-Olkin Distributions, and Related Bivariate Aging Properties
Full text linkNational Natural Science Foundation of China [10771090]A class of generalized bivariate Marshall-Olkin distributions, which includes as special cases the Marshall-Olkin bivariate exponential distribution and the Marshall-Olkin type distribution due to Muliere and Scarsini (1987) [19] are examined in this paper. Stochastic comparison results are derived, and bivariate aging properties, together with properties related to evolution of dependence along time, are investigated for this class of distributions. Extensions of results previously presented in the literature are provided as well. (C) 2011 Elsevier Inc. All rights reserved
Zhou yi lüe li
No full text王弼, 韓康伯注 ; 孔穎達正義.綫裝, 1函.框19.7x13.1公分, 9行21字, 小字雙行同. 白口, 無魚尾, 四周單邊. 版心中鐫"易疏"及卷次, 下記刻工.分上,下經 ; 卷一至三為上經, 卷四至九為下經.出版項據《明代版本圖錄初編》推定.卷一至六由王弼注, 卷七至九由韓康伯注.With: 經典釋文 : 周易音義 / 陸德明撰 -- 周易略例 / 王弼撰.鈐有"呂氏樂房藏書", "得良館藏書記"印.Xian zhuang, 1 han.Kuang 19.7 x 13.1 gong fen, 9 hang 21 zi, xiao zi shuang hang tong. Bai kou, wu yu wei, si zhou dan bian. Ban xin zhong juan "Yi shu" ji juan ci, xia ji ke gong.Fen shang, xia jing ; juan yi zhi san wei shang jing, juan si zhi jiu wei xia jing.Chu ban xiang ju "Ming dai ban ben tu lu chu bian" tui ding.Juan yi zhi liu you Wang Bi zhu, juan qi zhi jiu you Han Kangbo zhu.Wang Bi, Han Kangbo zhu ; Kong Yingda zheng yi.With: Jing dian shi wen : Zhou yi yin yi / Lu Deming zhuan -- Zhou yi lüe li / Wang Bi zhuan.Qian you "Lü shi Le fang cang shu", "De liang guan cang shu ji" yin
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
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New Findings on the Phase Transitions in Li(sub 1-x)CoO(sub 2) and Li(sub 1-x)NiO(sub 2) Cathode Materials During Cycling: In Situ Synchrotron X-Ray Diffraction Studies
No full textThe authors have utilized synchrotron x-ray radiation to perform ''in situ'' x-ray diffraction studies on Li{sub 1-x}CoO{sub 2} and Li{sub 1-x}NiO{sub 2} cathodes. A C/10 charging rate was used for a Li/Li{sub 1-x}CoO{sub 2} cell. For the Li/Li{sub 1-x}NiO{sub 2} cells, C/13 and C/84 rates were applied. The in situ XRD data were collected during the first charge from 3.5 to 5.2 V. For the Li{sub 1-x}CoO{sub 2} cathode, in the composition range of x = 0 to x = 0.5, a new intermediate phase H2a was observed in addition to the two expected hexagonal phases H1 and H2. In the region very close to x = 0.5, some spectral signatures for the formation of a monoclinic phase M1 were also observed. Further, in the x = 0.8 to x = 1 region, the formation of a CdI{sub 2} type hexagonal phase has been confirmed. However, this new phase is transformed from a CdCl{sub 2} type hexagonal phase, rather than from a monoclinic phase M2 as previously reported in the literature. For the Li{sub 1-x}NiO{sub 2} system, by taking the advantage of the high resolution in 2{theta} angles through the synchrotron based XRD technique, they were able to identify a two-phase coexistence region of hexagonal phase H1 and H2, which has been mistakenly indexed as a single phase region for monoclinic phase M1. Interesting similarities and differences between these two systems are also discussed
Spintronic and plasmonic applications of electrodeposition on semiconductors
No full textIn this thesis, metal electrodeposition on semiconductor substrates is investigated. We show that electrodeposition of metals on n-type Si and Ge is an excellent method
to create Schottky barriers and that this method has a number of unique advantages over other (physical) deposition methods. These advantages can be used to improve the prospects of applications in the area of Spintronics and Plasmonics.Firstly, the excellent current-voltage and capacitance-voltage characteristics of electrodeposited Schottky barriers indicate that they have an ideality factor close to unity and that the reverse bias leakage is orders of magnitude smaller than in
evaporated Schottky barriers. These characteristics can be used to make highly doped Schottky barriers in which all reverse bias current is due to tunnelling. For magnetic metals, these Schottky barriers hence allow spin-conserved conduction which is a necessary step towards semiconductor spin valves and spin transistors.Secondly, electrodeposition is not a line-of-sight-technique and can hence be used to grow three dimensional structures when an appropriate pattern is created. Self assembly of latex spheres is shown to change both qualitative and quantitatively
upon using a lithographically defined pattern. By using electrodeposition of gold around this latex sphere pattern nano-void array photonic crystals are created. We show that plasmonic modes are detectable in these arrays opening up the path to on-chip optical communication
Si(Li) X-ray astronomical spectroscopy
Full text linkThe general considerations involved in the choice of Si(Li) as a non-dispersive spectrometer for X-ray astronomy are discussed. In particular, its adaptation to HEAO-B is described as an example of the space-borne application of Si(Li) technology
Wang Li (1900-1986)
No full textWang Li (Wang Liaoyi) was one of the three most prominent linguists in China in the 20th century. He was born August 10, 1900, in what is now Bobai County of the Guangxi Zhuang Autonomous Area
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