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131.
The density of two initially independent condensates which are allowed to expand and overlap can show interferences as a function of time due to interparticle interaction. Two situations are separately discussed and compared: (1) all atoms are identical and (2) each condensate consists of a different kind of atoms. Illustrative examples are presented. 相似文献
132.
Elish Eyal Brandis Michal Haquin Gustavo Hershko Itzhak Yungrais Zohar Aviv Ofer Moyal Amiram Assulin Maor Nawi Yehuda Solomon Oren Zakon Yevgeni Rubinshtein Arnon Astrachan Boaz 《Journal of Radioanalytical and Nuclear Chemistry》2021,329(1):51-60
Journal of Radioanalytical and Nuclear Chemistry - An orphan radium-beryllium (Ra–Be) neutron source (Nuclear Chicago Corporation) detected inside a scrap metal shipping container, was seized... 相似文献
133.
Yehuda Pinchover 《Mathematische Annalen》1999,314(3):555-590
In this paper we discuss some new results concerning perturbation theory for second order elliptic partial differential equations
related to positivity properties of such equations. We continue the study of some different notions of “small” perturbations
and discuss their relations to comparisons of Green's functions, refined maximum and anti-maximum principles, ground state,
and the decay of eigenfunctions.
In particular, we show that if V is a positive function which is a semismall perturbation of a subcritical Schr?dinger operator H defined on a domain , and are the (Dirichlet) eigenfunctions of the equation , then for any , the function is bounded and has a continuous extension up to the Martin boundary of the pair , where is the ground state of H with a principal eigenvalue .
Received: 29 November 1998 相似文献
134.
Volatile organic compounds generated by cultures of bacteria and viruses associated with respiratory infections
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Amir Abd El Qader David Lieberman Yonat Shemer Avni Natali Svobodin Tsilia Lazarovitch Orli Sagi Yehuda Zeiri 《Biomedical chromatography : BMC》2015,29(12):1783-1790
Respiratory infections (RI) can be viral or bacterial in origin. In either case, the invasion of the pathogen results in production and release of various volatile organic compounds (VOCs). The present study examines the VOCs released from cultures of five viruses (influenza A, influenza B, adenovirus, respiratory syncitial virus and parainfluenza 1 virus), three bacteria (Moraxella catarrhalis, Haemophilus influenzae and Legionella pneumophila) and Mycoplasma pneumoniae isolated colonies. Our results demonstrate the involvement of inflammation‐induced VOCs. Two significant VOCs were identified as associated with infectious bacterial activity, heptane and methylcyclohexane. These two VOCs have been linked in previous studies to oxidative stress effects. In order to distinguish between bacterial and viral positive cultures, we performed principal component analysis including peak identity (retention time) and VOC concentration (i.e. area under the peak) revealing 1‐hexanol and 1‐heptadecene to be good predictors. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
135.
The crystal structure of U6Fe5Al8Si9 was re-determined by electron crystallography, using selected area electron diffraction (SAED) and high resolution (HRTEM) images, taken along the [0 0 1] direction. The obtained results are very similar to those found previously by X-ray powder diffraction. The differences between the atomic positions found by SAED and HRTEM images and those found by X-ray powder diffraction were 0.11 and 0.08 Å, respectively. 相似文献
136.
137.
Boris Bazanov Dr. Uzi Geiger Dr. Raanan Carmieli Dr. Dan Grinstein Dr. Shmuel Welner Prof. Yehuda Haas 《Angewandte Chemie (International ed. in English)》2016,55(42):13233-13235
Compelling evidence has been found for the formation and direct detection of the cyclopentazole anion (cyclo‐N5?) in solution. The anion was prepared from phenylpentazole in two steps: reduction by an alkali metal to form the phenylpentazole radical anion, followed by thermal dissociation to yield cyclo‐N5?. The reaction solution was analyzed by HPLC coupled with negative mode mass spectrometry. A signal with m/z 70 was eluted about 2.1 min after injection of the sample. Its identification as N5 was supported by single and double labeling with 15N, which yielded signals at m/z=71 and 72, respectively, with identical retention times in the HPLC column. MS/MS analysis of the m/z=70 signal revealed a dissociation product with m/z=42, which can be assigned to N3?. To our knowledge this is the first preparation of cyclo‐N5? in the bulk. The compound is indefinitely stable at temperatures below ?40 °C, and has a half‐life of a few minutes at room temperature. 相似文献
138.
We study the discreteness of the spectrum of Schrödinger operators which are defined on a class of radial N-dimensional rooted trees of a finite or infinite volume, and are subject to a certain mixed boundary condition. We present a method to estimate their eigenvalues using operators on a one-dimensional tree. These operators are called width-weighted operators, since their coefficients depend on the section width or area of the N-dimensional tree. We show that the spectrum of the width-weighted operator tends to the spectrum of a one-dimensional limit operator as the sections width tends to zero. Moreover, the projections to the one-dimensional tree of eigenfunctions of the N-dimensional Laplace operator converge to the corresponding eigenfunctions of the one-dimensional limit operator. 相似文献
139.
Nine novel compounds designated negombins A-I (1-9) were isolated, together with latrunculin, from the Tanzanian sponge Negombata sp. The nine are sacculatane type diterpenes, previously only known from liverworts. The structures of the compounds were elucidated by interpretation of MS and 1D and 2D NMR spectra. A possible biogenesis initiated by the naturally rare chloronium ion is suggested, possibly hinting to a guest microorganism as the source of the compounds. Compound 4 is toxic to brine shrimp larvae. 相似文献
140.
Yehuda Pinchover Kyril Tintarev 《Calculus of Variations and Partial Differential Equations》2007,28(2):179-201
Let Ω be a domain in , d ≥ 2, and 1 < p < ∞. Fix . Consider the functional Q and its Gateaux derivative Q′ given by If Q ≥ 0 on, then either there is a positive continuous function W such that for all, or there is a sequence and a function v > 0 satisfying Q′ (v) = 0, such that Q(u
k
) → 0, and in . In the latter case, v is (up to a multiplicative constant) the unique positive supersolution of the equation Q′ (u) = 0 in Ω, and one has for Q an inequality of Poincaré type: there exists a positive continuous function W such that for every satisfying there exists a constant C > 0 such that . As a consequence, we prove positivity properties for the quasilinear operator Q′ that are known to hold for general subcritical resp. critical second-order linear elliptic operators. 相似文献