151,170 research outputs found
Measurements of K S 0 - K L 0 asymmetries in the decays Λ c + → p K L , S 0 , p K L , S 0 π + π − and p K L , S 0 π 0
No full textAbstract Using e + e − annihilation data sets corresponding to an integrated luminosity of 4.5 fb −1, collected with the BESIII detector at center-of-mass energies between 4.600 and 4.699 GeV, we report the first measurements of the absolute branching fractions B Λ c + → p K L 0 = (1.67 ± 0.06 ± 0.04)%, B Λ c + → p K L 0 π + π − = (1.69 ± 0.10 ± 0.05)%, and B Λ c + → p K L 0 π 0 = (2.02 ± 0.13 ± 0.05)%, where the first uncertainties are statistical and the second systematic. Combining with the known branching fractions of Λ c + → p K S 0 , Λ c + → p K S 0 π + π − , and Λ c + → p K S 0 π 0 , we present the first measurements of the K S 0 - K L 0 asymmetries R Λ c + K S , L 0 X = B Λ c + → K S 0 X − B Λ c + → K L 0 X B Λ c + → K S 0 X + B Λ c + → K L 0 X in charmed baryon decays: R Λ c + p K S , L 0 = − 0.025 ± 0.031 , R Λ c + p K S , L 0 π + π − = − 0.027 ± 0.048 and R Λ c + p K S , L 0 π 0 = − 0.015 ± 0.046 . No significant asymmetries with statistical significance are observed
Tour to China, Concert Nanjing, Concert Xi'an; recitals with Ma, L. (cellist), Yin, N. (violinist), Ju, Y. (pianist) Dong, L. (flautist), Ma Li, L. (flautist), Qiao Liang, Q. (flautist) in Nanjing performing Beethoven: Symphony No 1 arr Hummel ( Edition Grodd), Taira:Synchcronie, Bozza: Jour d ete Quartet; Koechlin: Sonata, Hosokawa: Kuroda Bushi Flute and in Xi'an with Dong, L. (flautist),, Gao, Q. (Flautist), Gao, Y. (Flautist), Zhang, K. (Flautist) .
No full textRecitals with Ma, L. (cellist), Yin, N. (violinist), Ju, Y. (pianist) Dong, L. (flautist), Ma Li, L. (flautist), Qiao Liang, Q. (flautist) in Nanjing performing Beethoven: Symphony No 1 arr Hummel ( Edition Grodd), Taira:Synchcronie, Bozza: Jour d ete Quartet; Koechlin: Sonata, Hosokawa: Kuroda Bushi Flute and in Xi'an with Dong, L. (flautist),, Gao, Q. (Flautist), Gao, Y. (Flautist), Zhang, K. (Flautist) .Public concerts including world premier of Beethoven Symphony No 1 arr Hummel Edition Grodd, with Head of Strings Prof Ma and colleagues in Nanjing. In Xi'an performance with Head of Flutes Professor Gao. Repertoire: Beethoven: Symphony No 1 arr Hummel ( Edition Grodd), Taira:Synchcronie, Bozza: Jour d ete Quartet; Koechlin: Sonata, Hosokawa: Kuroda Bushi Flutehttp://www.xacom.edu.cn/info/1055/18653.ht
Synthesis of Co(3)O(4) nanowire arrays supported on Ni foam for removal of volatile organic compounds
No full textCrystalline Co3O4 nanowire arrays freely supported on Ni foam are successfully synthesized using a template-free method. The effects of reaction time, concentration of reactants, and temperature on the morphology of the nanowires are studied. The results indicate that uniform Co3O4 nanowires could be synthesized at 90 degrees C, and a transformation of the samples' morphology from nanoparticles to nanowires to microrods is observed by controlling the concentration of the reactants. The well-ordered nanowires synthesized under the selected reaction conditions are composed of spinel Co3O4 with diameters of 500-580 nm and lengths of 6-8 microm. These nanowires show good catalytic activity for the ozone catalytic oxidation of toluene.Hui, K. N.; Yin, Cui-Lei; Hui, K. S.; Lee, J. Y.; Li, M.; Lee, S. K.; Tsui, K. L.; Chao, Christopher Y H; Kwong, C. W
K- And L-theory of graph products of groups
No full textWe compute the group homology, the algebraic K- and L-groups, and the topological K-groups of right-angled Artin groups, right-angled Coxeter groups, and more generally, graph products
ljt-uiuc/H-k-c: H-k-c
No full textH-k-c package:
Generalized H-k after harmonic correction on receiver functions
a modification of H-k method by Zhu and Kanamori (2000)
by Jiangtao Li, Xiaodong Song, Pan Wang, and Lupei Zhu
Reference: Li, J., Song, X., Wang, P., & Zhu, L. (2019). A generalized H-k method with harmonic corrections on Ps and its crustal multiples in receiver functions. J. Geophys. Res. Solid Earth, 124(4), 3782-3801
Contact: [email protected]; [email protected]
Geochemical characterisation of the thermo-mineral waters of Greece
No full textGeothermal areas of Greece are located in regions affected by recent volcanism and in continental basins characterised by elevated heat flow. Many of them are found along the coast, and thus, water is often saline due to marine intrusion. In the current study, we present about 300 unpublished and literature data from thermal and cold mineral waters collected along Greece. Samples were analysed for major ions, Li, SiO2 and isotopes in water. Measured temperatures range from 6.5 to 98 °C, pH from 1.96 to 11.98, while Total Dissolved Solutes (TDS) from 0.22 to 51 g/L. Waters were subdivided into four main groups: (1) thermal; (2) cold; (3) acidic (pH < 5); and (4) hyperalkaline (pH > 11). On statistical basis, thermal waters were subdivided into subgroups according to both their temperature [warm (< 29 °C), hypothermal (29–48 °C), thermal (48–75 °C) and hyperthermal (> 75 °C)] and TDS [low salinity (< 4 g/L), brackish (4–30 g/L) and saline (> 30 g/L)]. Cold waters were subdivided based on their pCO2 [low (< 0.05 atm), medium (0.05–0.85 atm) and high (> 0.85 atm)]. δ18O–H2O ranges from − 12.7 to + 2.7‰ versus SMOW, while δ2H–H2O from − 91 to + 12‰ versus SMOW being generally comprised between the Global Meteoric Water Line and the East Mediterranean Meteoric Water Line. Positive δ18O shifts with respect to the former are mostly related to mixing with seawater, while only for a few samples these shifts point to high-temperature water–rock interaction processes. Only a few thermal waters gave reliable geothermometric estimates, suggesting reservoir temperatures between 80 and 260 °C
A Study of the Thermodynamics and Kinetics of LiₓFePO₄ as a Cathode Material for Li Batteries
No full textOlivine-type LiFePO4 has been recognized as one of the most promising cathode materials for rechargeable Li batteries. Its advantages include high capacity, high stability, nontoxicity, and low cost. Our methods for synthesizing nanocrystalline LixFePO4 with the olivine structure are described. Solid-state reactions and precipitation reactions were both successful, and ball milling was especially effective at reducing crystallite sizes. Diffractometry and microscopy were used to characterize these materials, and results of impurity phases, excess Fe3+, and internal stresses are reported for the different types of synthesis.
Applications of lithium-ion batteries, including automotive applications, require fast kinetics and high conductivity of ions and electrons. Unfortunately, LixFePO4 has the electronic structure of an insulator, an entirely unsatisfactory situation if it is to be used as a battery electrode. Electrical conductivity in LixFePO4 occurs by the motion of small polarons, which are valence electrons at Fe atoms plus their distorted local environments. Electrical conductivity of LixFePO4 is interpreted in terms of small polaron hopping. There are other factors of importance in these measurements, such as impurities or defects that block the one-dimensional conduction channels of the olivine structure of LixFePO4.
We studied the polaron hopping directly, which allows us to understand the intrinsic electrical conductivity, and how it depends on microstructure and composition of LixFePO4. The experimental technique was Mossbauer spectrometry, which has been used for many years as a means for determining the fractions of Fe2+ and Fe3+ in a material. Usually the spectral signatures of Fe2+ and Fe3+ are distinct. When valence electrons hop between Fe2+ and Fe3+ at a frequency of 108 Hz or higher, however, the valence changes during the timescale of the Mossbauer measurement and the spectrum is blurred. By measuring Mossbauer spectra at elevated temperatures, we can determine the fractions of Fe atoms participating in polaron hopping, and determine the activation energy of the process. From this we estimate intrinsic electrical conductivities of 10-7S/cm at room temperature for nanocrystalline Li0.5FePO4, for example. We find a comparable conductivity for LixFePO4 prepared as a solid solution, but the conductivity of conventional LixFePO4 is much lower.
There has been much discussion about how surface area might thermodynamically stabilize the solid solution phase of nanocrystalline LixFePO4. In a series of X-ray diffraction measurements, some at elevated temperatures, we found the solid solution phase of LixFePO4 to be especially robust at room temperature when the material was prepared in nanocrystalline form. Moreover, the consistent phase transition temperature around 200°C was observed, as evidence for the unchanged equilibrium phase diagram by crystallite size. This is consistent with our evaluation on the boundaries of the two-phase mixture of triphylite and heterosite during Li insertion and extraction. Profiles of entropy and enthalpy changes were evaluated by open-circuit voltage measurements. The boundaries were found at x=0.05 and 0.95 in the LixFePO4 with crystal size of 70 nm, similar to the reported values on bulk-LixFePO4. These are important in practice, because electrochemical lithiation and delithiation at room temperature should remain as a two-phase transformation, even if a solid solution of lithium is present in the initial electrode material.</p
K-LLVM: A Relatively Complete Semantics of LLVM IR
No full textLLVM [Lattner and Adve, 2004] is designed for the compile-time, link-time and run-time optimization of programs written in various programming languages. The language supported by LLVM targeted by modern compilers is LLVM IR [llvm.org, 2018]. In this paper we define K-LLVM, a reference semantics for LLVM IR. To the best of our knowledge, K-LLVM is the most complete formal LLVM IR semantics to date, including all LLVM IR instructions, intrinsic functions in the LLVM documentation and Standard-C library functions that are necessary to execute many LLVM IR programs. Additionally, K-LLVM formulates an abstract machine that executes all LLVM IR instructions. The machine allows to describe our formal semantics in terms of simulating a conceptual virtual machine that runs LLVM IR programs, including non-deterministic programs. Even though the K-LLVM memory model in this paper is assumed to be a sequentially consistent memory model and does not include all LLVM concurrency memory behaviors, the design of K-LLVM’s data layout allows the K-LLVM abstract machine to execute some LLVM IR programs that previous semantics did not cover, such as the full range of LLVM IR behaviors for the interaction among LLVM IR casting, pointer arithmetic, memory operations and some memory flags (e.g. readonly) of function headers. Additionally, the memory model is modularized in a manner that supports investigating other memory models. To validate K-LLVM, we have implemented it in [Roşu, 2016], which generated an interpreter for LLVM IR. Using this, we ran tests including 1,385 unit test programs and around 3,000 concrete LLVM IR programs, and K-LLVM passed all of them
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