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991.
Mitra Ghassemzadeh Majid M. Heravi Rahim Hekmat‐Shoar Bernhard Neumüller 《无机化学与普通化学杂志》2003,629(14):2438-2439
The reaction of 4‐Amino‐6‐methyl‐1, 2, 4‐triazine‐3(2H)‐thione‐5‐one (HAMTTO) with n‐butyl lithium in dimethoxyethane (DME) gives the complex [Li(DME)(AMTTO)] ( 1 ). 1 was characterized by elemental analysis, IR‐ and mass‐spectrometry and an X‐ray structure analysis [space group P21/n, Z = 4, lattice dimensions at —80 °C: a = 867.6(1), b = 1721.5(2), c = 931.8(1) pm, β = 112.81(1)°, R1 = 0.0315. The complex is a coordination polymer along [001] with a zig‐zag arrangement. 相似文献
992.
Wolfrum S Pinzón JR Molina-Ontoria A Gouloumis A Martín N Echegoyen L Guldi DM 《Chemical communications (Cambridge, England)》2011,47(8):2270-2272
Electron accepting Sc(3)N@C(80) promotes long-range charge transfer events evolving from photoexcited metalloporphyrins to afford radical ion pair states with lifetimes in the range of μs. 相似文献
993.
994.
995.
Abazov VM Abbott B Acharya BS Adams M Adams T Alexeev GD Alkhazov G Alton A Alverson G Alves GA Aoki M Arov M Askew A Åsman B Atramentov O Avila C BackusMayes J Badaud F Bagby L Baldin B Bandurin DV Banerjee S Barberis E Baringer P Barreto J Bartlett JF Bassler U Bazterra V Beale S Bean A Begalli M Begel M Belanger-Champagne C Bellantoni L Beri SB Bernardi G Bernhard R Bertram I Besançon M Beuselinck R Bezzubov VA Bhat PC Bhatnagar V Blazey G Blessing S Bloom K Boehnlein A Boline D Boos EE 《Physical review letters》2011,107(12):121802
We present a measurement of the ratio of top quark branching fractions R=B(t→Wb)/B(t→Wq), where q can be a d, s, or b quark, in the lepton+jets and dilepton tt final states. The measurement uses data from 5.4 fb(-1) of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider. We measure R=0.90±0.04, and we extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |V(tb)| as |V(tb)|=0.95±0.02, assuming unitarity of the 3×3 CKM matrix. 相似文献
996.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Agelou M Agram JL Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Andeen T Anderson S Andrieu B Arnoud Y Askew A Asman B Jesus AC Atramentov O Autermann C Avila C Badaud F Baden A Bagby L Baldin B Balm PW Banerjee P Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Begalli M Begel M Bellavance A Beri SB Bernardi G Bernhard R Bertram I Besançon M 《Physical review letters》2005,95(16):161602
We present the results of a search for the effects of large extra spatial dimensions in pp collisions at sqrt[s] = 1.96 TeV in events containing a pair of energetic muons. The data correspond to 246 pb(-1) of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider. Good agreement with the expected background was found, yielding no evidence for large extra dimensions. We set 95% C.L. lower limits on the fundamental Planck scale between 0.85 and 1.27 TeV within several formalisms. These are the most stringent limits achieved in the dimuon channel to date. 相似文献
997.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Agelou M Agram JL Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Andeen T Anderson S Andrieu B Anzelc MS Arnoud Y Arov M Askew A Asman B Jesus AC Atramentov O Autermann C Avila C Ay C Badaud F Baden A Bagby L Baldin B Bandurin DV Banerjee P Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Begalli M Begel M Belanger-Champagne C Bellavance A Benitez JA Beri SB 《Physical review letters》2006,97(24):241801
We report a measurement of the Bs(0) lifetime in the semileptonic decay channel Bs(0) --> Ds- mu+ nuX (and its charge conjugate), using approximately 0.4 fb(-1) of data collected with the D0 detector during 2002-2004. Using 5176 reconstructed Ds- mu+ signal events, we have measured the Bs(0) lifetime to be tau(Bs(0))=1.398+/-0.044(stat)(-0.025)(+0.028)(syst) ps. This is the most precise measurement of the Bs(0) lifetime to date. 相似文献
998.
Andreas F. Molisch Bernhard P. Oehry Walter Schupita Gottfried Magerl 《Optics Communications》1992,90(4-6):245-250
We derive a new, simplified method for the computation of trapping effects in coupled three-level atomic systems. The linearity of the Holstein radiation trapping equation allows the reduction of the general rate equation to the solution of the basic two-level Holstein equation and to an algebraic eigenvalue problem. The method is applied to the numerical simulation of the quantum efficiency and the signal bandwidth of thallium atomic line filters. With a pumping scheme that achieves population inversion between the ground state and the metastable state, 90% quantum efficiency and 10 MHz signal bandwidth can be achieved, while in noninverting pumping schemes, even quite high pump intensities result in less than 60% quantum efficiency and 8 MHz signal bandwidth. A tradeoff between quantum efficiency, signal bandwidth and pump power is possible. 相似文献
999.
Crystal Structure and Vibrational Spectrum of (H2NPPh3)2[SnCl6]·2CH3CN Single crystals of (H2NPPh3)2[SnCl6]·2CH3CN ( 1 ) were obtained by oxidative addition of tin(II) chloride with N‐chloro‐triphenylphosphanimine in acetonitrile in the presence of water. 1 is characterized by IR and Raman spectroscopy as well as by a single crystal structure determination: Space group , Z = 2, lattice dimensions at 193 K: a = 1029.6(1), b = 1441.0(2), c = 1446.1(2) pm, α = 90.91(1)°, β = 92.21(1)°, γ = 92.98(1)°, R1 = 0.0332. 1 forms an ionic structure with two different site positions of the [SnCl6]2? ions. One of them is surrounded by four N‐hydrogen atoms of four (H2NPPh3)+ ions, four CH3CN molecules form N–H···N≡C–CH3 contacts with the other four N‐hydrogen atoms of the cations. Thus, 1 can be written as [(H2NPPh3)4(CH3CN)4(SnCl6)]2+[SnCl6]2?. 相似文献
1000.