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31.
S. J. Blundell I. M. Marshall B. W. Lovett F.L. Pratt W. Hayes M. Kurmoo S. Takagi T. Sugano 《Hyperfine Interactions》2001,133(1-4):169-177
Positive muons can be implanted into organic and molecular magnets in order to study their internal magnetic field distribution and any associated dynamics. The muon behaves essentially as a microscopic magnetometer, sensitive to local magnetic order and magnetic fluctuations. We describe some recent experiments using this technique which were performed on a variety of organic systems, including nitronyl nitroxide magnets and materials with spin-Peierls ground states, MEM(TCNQ)2 and DEM(TCNQ)2, and demonstrate how the technique can give information concerning their ground states. 相似文献
32.
Sandro Gail Roger F. Cracknell Dáire Corrigan Andrea Festa Varun Shankar Benoit Poulet Guy Lovett Rene D. Büttgen Karl A. Heufer Roberto Mariconti Matteo Cucchi Fabio Mortellaro 《Proceedings of the Combustion Institute》2021,38(4):5643-5653
Simple surrogate formulations for gasoline are useful for modelling purposes and for comparing experimental results using a carefully designed fuel. Simple three-component surrogates based on primary reference fuels (PRF) and Toluene (TPRF) are frequently used to match the antiknock properties of actual gasoline fuels through the RON and MON. However, using PRF or TPRFs to test or to calibrate gasoline engines is still challenging, with the main difficulty being the capabilities of PRF fuels to match the physical properties of the road fuel such density, volatility (DVPE) and the distillation curve. To overcome such issues, an alternative to TPRF is presented in this work with a focus on premium fuel (RON98 EN228). This alternative consists of replacing some or all of isooctane by isopentane. In the event of total replacement, a three-component “THIP” (Toluene, Heptane, IsoPentane) surrogate fuel is produced. The physical and combustion properties of isopentane makes it easier to create surrogates that can match the DVPE, RON, MON and distillation characteristics of a real fuel. Furthermore, the use of isopentane allows the definition of a wider range of surrogate fuel compositions that can replicate the RON and MON of a given fuel. Surrogate formulations were developed at Shell Global Solutions that matched the RON, MON and selected physical properties of a reference premium gasoline (RPG). A Rapid Compression Machine (RCM) in PCFC was used to demonstrate that those surrogates can reproduce the essential autoignition characteristics of the selected RPG. Two mechanisms were used to predict RCM data and showed reasonable agreement, opening some perspective for further investigations. Finally, an engine test performed at Ferrari test facilities demonstrated that simple surrogates containing isopentane can be used to closely match the knock-limited combustion phasing of an RPG. In this paper, it is demonstrated such surrogates have advantages compared to TPRFs in being able to match the properties of a real fuel and that the surrogate approach is consistent with RCM data and engine results. 相似文献
33.
Formal synthesis of angiogenesis inhibitor NM-3 总被引:1,自引:0,他引:1
We report the formal synthesis of angiogenesis inhibitor NM-3 (1) in six steps from either of the 2,4-dimethoxyhalobenzenes 13a,b or 3,5-dimethoxychlorobenzene (13c). The first key reaction is the regiospecific alkylation/rearrangement between the aryne derived from 13a-c with sodium diethylmalonate in THF to produce diester 11, which after hydrolysis and cyclization affords homophthalic anhydride 3. The second is the reaction of anhydride 3 with either ethyl 2-methylmalonate (28a), in the presence of 1,1'-carbonyldiimidazole, or ethyl-2-methylmalonyl chloride (28b) under basic conditions to afford key isocoumarin 27. The conversion of 27 constitutes a formal synthesis of NM-3. 相似文献
34.
Motivated by the Beck‐Fiala conjecture, we study discrepancy bounds for random sparse set systems. Concretely, these are set systems (X,Σ), where each element x ∈ X lies in t randomly selected sets of Σ, where t is an integer parameter. We provide new bounds in two regimes of parameters. We show that when |Σ| ≥ |X| the hereditary discrepancy of (X,Σ) is with high probability ; and when |X| ? |Σ|t the hereditary discrepancy of (X,Σ) is with high probability O(1). The first bound combines the Lovász Local Lemma with a new argument based on partial matchings; the second follows from an analysis of the lattice spanned by sparse vectors. 相似文献
35.
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37.
Watt AA Sambrook MR Porfyrakis K Lovett BW El Mkami H Smith GM Briggs GA 《Chemical communications (Cambridge, England)》2006,(18):1944-1946
In this communication we demonstrate a directly-bonded crystalline fullerene superlattice and show that the incorporation of spin-active N@C60 endohedral fullerenes is readily achieved to give an atomic-molecular hybrid spin-active superlattice material. 相似文献
38.
R.D. Ehrlich B. Lovett M. Mishina P.A. Souder J. Snyder M.E. Zeller D.M. Lazarus I. Nakano 《Physics letters. [Part B]》1977,71(2):455-459
The polarization parameter has been measured in K?p elastic scattering at eight incident beam momenta between 650 MeV/c and 1071 MeV/c throughout a center of mass angular range of . Experimental results and coefficients of Legendre polynomial fits to the data are presented and compared with other measurements and partial wave analysis. 相似文献
39.
A.R. Forster D.L. Anderson R.J. Lovett M.L. Parsons 《Spectrochimica Acta Part B: Atomic Spectroscopy》1981,36(10):1023-1027
In a recent publication it was predicted that either or both the In 252.137 nm or Co 252.136 nm transitions were misassigned. An experimental evaluation of these transitions was made with a scanning echelle monochromator system. The In 252.137 nm transition has been reassigned at 252.134 nm and the Co 252.136 nm was verified. 相似文献
40.
We present a novel scheme for performing a conditional phase gate between two spin qubits in adjacent semiconductor quantum dots through delocalized single exciton states, formed through the interdot F?rster interaction. We consider two resonant quantum dots, each containing a single excess conduction band electron whose spin embodies the qubit. We demonstrate that both the two-qubit gate and arbitrary single-qubit rotations may be realized to a high fidelity with current semiconductor and laser technology. 相似文献