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81.
Brodie-Linder N Le Caër S Alam MS Renault JP Alba-Simionesco C 《Physical chemistry chemical physics : PCCP》2010,12(42):14188-14195
Measurement of H(2) production from electron irradiation (10 MeV) on SBA-15 materials has shown that adsorbed water is attacked preferentially. Silanol groups are only attacked when they are in the majority with respect to adsorbed water, however they are much less efficient at producing H(2). The comparison between water content before and after electron irradiation and the corresponding H(2) production indicates that water desorption is the main route to adsorbed water loss for SBA-15 materials. On the other hand, surface silanol groups are more susceptible to attack, leading to H(2) production when SBA-15 samples have undergone extensive thermal treatment. Electron irradiation of SBA-15-Cu materials has shown that the presence of Cu(II) on the surface reduces and inhibits the production of H(2.) This inhibiting power affects adsorbed water bonded to grafted copper but not surface silanol groups. 相似文献
82.
Search for a standard model Higgs boson in the H→ZZ→ℓ(+)ℓ(-)νν decay channel with the ATLAS detector
Aad G Abbott B Abdallah J Abdelalim AA Abdesselam A Abdinov O Abi B Abolins M Abramowicz H Abreu H Acerbi E Acharya BS Adams DL Addy TN Adelman J Aderholz M Adomeit S Adragna P Adye T Aefsky S Aguilar-Saavedra JA Aharrouche M Ahlen SP Ahles F Ahmad A Ahsan M Aielli G Akdogan T Åkesson TP Akimoto G Akimov AV Akiyama A Alam MS Alam MA Albert J Albrand S Aleksa M Aleksandrov IN Alessandria F Alexa C Alexander G Alexandre G Alexopoulos T Alhroob M Aliev M Alimonti G Alison J Aliyev M Allport PP 《Physical review letters》2011,107(22):221802
A search for a heavy standard model Higgs boson decaying via H→ZZ→→?(+)?(-)νν, where ?=e, μ, is presented. It is based on proton-proton collision data at √s=7 TeV, collected by the ATLAS experiment at the LHC in the first half of 2011 and corresponding to an integrated luminosity of 1.04 fb(-1). The data are compared to the expected standard model backgrounds. The data and the background expectations are found to be in agreement and upper limits are placed on the Higgs boson production cross section over the entire mass window considered; in particular, the production of a standard model Higgs boson is excluded in the region 340相似文献
83.
S.D. Gopal Ram G. Ravi MR. Manikandan T. Mahalingam M. Anbu Kulandainathan 《Superlattices and Microstructures》2011,50(4):296-302
In the present work, a controlled growth of ZnO nanostructures by manipulating Zn metal ion concentration by the chelating action of ethylene diaminetetra acetic acid in hydrothermal method is studied. EDTA produces metal–chelate complex by the formation of bidentate ligand with Zn2+ in the solution and diminishes the reactivity of Zn metal cations. Concentration of EDTA in the mother solution was varied in different ranges like 3, 5 and 10 mM while retaining the zinc metal salt and the NaOH concentration the same. Three different morphologies of wurtzite structured ZnO nanostructures such as nanorods-bunch, separate/discrete uniformly sized hexagonal nanorods and tapered flower petals like shapes are achieved by 3, 5 and 10 mM strengths of EDTA, respectively. The medium concentration 5 mM of EDTA is found to have moderate control over producing ZnO nanostructures of uniform diameter and a high aspect (length to diameter) ratio. An array of vertically aligned free standing ZnO nanorods with uniform spacing is successfully achieved by the addition of 5 mM of EDTA in the mother solution and the same is studied for its fluorescence property at an excitation of 325 nm and it has exhibited a characteristic UV emission of ZnO around 383 nm. 相似文献
84.
Reza Shams Alam Masoud Kavosh TehraniMahmood Moradi Ehsaneh HosseinpourAli Sharbati 《Journal of magnetism and magnetic materials》2011,323(8):1040-1043
The effect of Mg2+, Co2+and Ti4+ substitution on microwave absorption has been studied for BaMg0.5Co0.5Ti1.0Fe10O19 ferrite-acrylic resin composite in frequency range from 13 to 20 GHz. X-ray diffraction (XRD), scanning electron microscopy (SEM), vector network analysis and vibrating sample magnetometry (VSM) were employed to analyze structure, electromagnetic and microwave absorption properties of prepared ferrite. The obtained results of reflectivity demonstrate that by varying matching thickness along with weight percentage of ferrite to acrylic resin, the bandwidth coupled with reflection loss values of prepared composites can be easily tuned. Based on microwave measurement on reflectivity, it is found that BaMg0.5Co0.5Ti1.0Fe10O19 is a good candidate for wideband electromagnetic compatibility and other practical applications at high frequency. 相似文献
85.
The recently proposed criteria for naked blackholes are conveniently rephrased. It is shown that twosolutions of dilaton-Maxwell gravity, satisfying weakenergy conditions, represent naked blackholes. 相似文献
86.
Alqasoumi Saleh I. Alam Prawez Al-Rehaily Adnan J. Shakeel Faiyaz Abdel-Kader Maged S. 《平面色谱法杂志一现代薄层色谱法》2011,24(1):48-52
JPC – Journal of Planar Chromatography – Modern TLC - A densitometric high-performance thin-layer chromatographic (HPTLC) method for analysis of hydroquinone has been developed and... 相似文献
87.
88.
D. Kilburn D. Bamford G. Dlubek J. Pionteck M. A. Alam 《Journal of Polymer Science.Polymer Physics》2003,41(23):3089-3093
The temperature dependence of the mean size of local free volumes in an amorphous atactic (aPP) and a semicrystalline syndiotactic polypropylene (sPP), and an amorphous ethylene‐propylene copolymer (E‐co‐P48) has been studied. Pressure‐volume‐temperature (PVT) experiments were performed for aPP, from which the hole fraction h of the Simha‐Somcynsky theory and the number density of holes were estimated. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 3089–3093, 2003 相似文献
89.
Teppei Yoshioka Md Zahangir Alam Tomonari Ogata Takamasa Nonaka Seiji Kurihara 《Liquid crystals》2004,31(9):1285-1291
Several chiral azobenzene compounds having different chiral substituents were synthesized. A cholesteric phase was induced by mixing each chiral azobenzene compound with a host non-chiral nematic liquid crystal (E44). The helical twisting power (HTP) as well as the change in HTP by trans-cis photoisomerization of the chiral azobenzene compound was dependent on the structure of the chiral substituents. A compensated nematic phase was induced by combination of E44, a chiral azobenzene compound and a non-photochromic chiral compound. Reversible switching between the compensated nematic phase and cholesteric phase was brought about by trans-cis photoisomerization of the chiral azobenzene compound in the liquid crystalline systems. An azobenzene compound substituted with a menthyl group showed the highest efficiency as the trigger for the switching; this efficiency was related to the compactness of the chiral group substituted within the azobenzene core moiety. 相似文献
90.
Optical shadow-casting (OSC) technique has shown excellent potential for optically implementing two-operand parallel logic gates and array logic operations. The 16 logic functions for two binary patterns (variables) are optically realizable in parallel by properly configuring an array of 2×2 light emitting diodes. In this paper, we propose an enhanced OSC technique for implementing four-operand parallel logic gates. The proposed system is capable of performing 216 logic functions by simply programming the switching mode of an array of 4×4 light emitting diodes in the input plane. This leads to an efficient and compact realization scheme when compared to the conventional two-operand OSC system. 相似文献