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1.
In this paper we use the Red-Black method as the data parallel algorithm (CM Fortron to solve Navier-Stokes equations on CM-5 parallel supercomputer.
  • ? The Steady Navier-Stokes Equation
  • ? Linearization of the Navier-Stokes Equation
  • ? Discretization
  • ? Numerical Results
  •   相似文献   

    2.
    Two problems for task schedules in a multiprocessor parallel system are discussed in this paper:
    1. Given a partially ordered set of tasks represented by the vertices of an acyclic directed graph with their corresponding processing times, derive the lower bound on the minimum time(LBMT) needed to process the task graph for a given number of processors.
    2. Determine the lower bound on minimum number of processors(LBMP) needed to complete those tasks in minimum time. It is shown that the proposed LBMT is sharper than previously known values and the computational aspects of these bounds are also discussed.
      相似文献   

    3.
    In this paper, we present a large-update primal-dual interior-point method for symmetric cone optimization(SCO) based on a new kernel function, which determines both search directions and the proximity measure between the iterate and the center path. The kernel function is neither a self-regular function nor the usual logarithmic kernel function. Besides, by using Euclidean Jordan algebraic techniques, we achieve the favorable iteration complexity O( r~(1/2)(log r)~2 log(r/ ε)), which is as good as the convex quadratic semi-definite optimization analogue.  相似文献   

    4.
    Zuo-Hong Li 《科学通报(英文版)》2014,59(29-30):3771-3786
    We report some applications of QCD light cone sum rules (LCSR) to \(B\) meson weak decays. Special emphasis is on estimates of the form factors for \(B\) decays into a pseudoscalar ( \(P\) )/vector ( \(V\) ) meson, with a certain chiral current correlator. The main new ingredient, as compared with the case of the standard correlators, is that in the operator product expansion calculations, the contributions due to the twist-3 distribution amplitudes of the related light mesons, which are less known and would bring a larger uncertainty to the calculations with the standard correlators, cancel out fully in the \(B\rightarrow P\) case and do out partially in the \(B\rightarrow V\) one. An important observation, which is similar to that in soft collinear effective theory, is made in twist-3 approximation: whereas only one independent form factor is needed for parameterizing the hadronic matrix elements for a \(B\rightarrow P\) transition induced by all the relevant heavy-light quark currents, there exist two independent form factors under the condition of neglecting the terms suppressed by a factor of \(m_V^2\) , for the \(B\rightarrow V\) transition. Therefore, the improved LCSR approach could be of stronger predictive power for the weak form factors. Also, this approach is employed to understand the \(B\rightarrow D\) transitions by introducing a leading twist-2 DA for an energetic \(D\) meson, combined with some of other QCD-based approaches. A detailed QCD next-to-leading order calculation of the \(B\rightarrow \pi \) form factors is presented for an illustrative purpose, and the sum rule results are used to extract the Cabibbo–Kobayashi–Maskawa matrix element \(|V_{ub}|\) from the latest BaBar data.  相似文献   

    5.
    In this article, an effective feasible method to synthesize translocator protein 18kDa (TSPO) imidazopyridine ligand 7 is discussed. A new procedure for the synthesis of the key intermediate 17 has been developed in four steps (condensation, diazo reaction, hydrolysis, amidation) from 2-aminopyridine 18. The overall yield was increased from 18% to 31.6%. One of the key steps is using activated copper powder as a catalyst in several cycles. Finally, reduction of 17 with Zn dust completed the synthesis of TSPO imidazopyridine ligand 7 in 86% yield.  相似文献   

    6.
    In Zhang's recent works,a second-order Mehrotra-type predictor-corrector algorithm for linear optimization was extended to semidefinite optimization and derived that the algorithm for semidefinite optimization had O(n~(3/2)log(X~0)~T·S~0/ε) iteration complexity based on the NT direction as Newton search direction. In this paper, we extend the second-order Mehrotra-type predictor-corrector algorithm for linear optimization to semidefinite optimization and discuss the polynomial convergence of the algorithm by modifying the corrector direction and new iterates. It is proved that the iteration complexity is reduced to O(n~(3/2)log(X~0)~T·S~0/ε), which coincides with the currently best iteration bound of Mehrotra-type predictor-corrector algorithm for semidefinite optimization.  相似文献   

    7.
    In this short review, we present the current status about the theoretical and experimental studies for some important semileptonic decays of \(B/B_s\) mesons. We firstly gave a brief introduction for the experimental measurements for \(B/B_s \rightarrow P (l^+l^-, l^-\bar{\nu }_l, \nu \bar{\nu })\) decays, the BaBar’s \(R(D)\) and \(R(D^*)\) anomaly, the \(P_5^\prime \) deviation for \(B^0 \rightarrow K^{*0} \mu ^+ \mu ^-\) decay. We then made a careful discussion about the evaluations for the relevant form factors in the light-cone QCD sum rule, the heavy quark effective theory, and the perturbative QCD factorization approach. By using the form factors calculated in the perturbative (pQCD) approach, we then calculate and show the pQCD predictions for the decay rates of many semileptonic decays of \(B/B_s\) mesons. We also made careful phenomenological analysis for these pQCD predictions and found, in general, the following points: (a) For all the considered \(B/B_s\) semileptonic decays, the next-to-leading order pQCD predictions for their decay rates agree well with the data and those from other different theoretical methods; (b) For \(R(D)\) and \(R(D^*)\) , the pQCD predictions agree very well with the data, the BaBar’s anomaly of \(R(D^{(*)})\) are therefore explained successfully in the standard model by employing the pQCD approach; and (c) We defined several new ratios \(R_D^{l,\tau }\) and \(R_{D_s}^{l,\tau }\) , they may be more sensitive to the QCD dynamics which controls the \(B/B_s \rightarrow (D^{(*)},D_s^{(*)} )\) transitions than the old ratios, we therefore strongly suggest LHCb and the forthcoming Super- \(B\) experiments to measure these new ratios.  相似文献   

    8.
    In order to solve the parallel algorithm of Petri net system with concurrent function, so as to achieve the parallel control and simulation operation of this system, this paper proposes the function partition completeness theory and algorithms of Petri net parallelization, thereby providing the theoretical support for the realization of Petri parallel algorithms. Firstly, according to the concurrent characteristics of Petri net model, we analyze the parallelism of Petri net system; then, by giving the solving process of place invariants and the function partitioning of Petri net, we propose the function partitioning conditions and determination theorem of Petri net parallelization, and conduct its theoretical proof and practical verification. On this basis, we conduct the theoretical study and analysis on the situation that Petri net system has several kinds of parallel function partitioning, propose the completeness theorem of parallelism function partitioning in Petri net system, and verify it. Finally, we give the algorithms, application examples and simulation experiment results of parallel function partitioning of Petri net systems based on place invariant. The theoretical proof and experimental results show that the function partitioning conditions and completeness theory of Petri net parallelization based on place invariant are correct, and the parallel algorithms under such theoretical basis are also correct and effective.  相似文献   

    9.
    Two new sesquiterpenoids,(1S,2R)-dihydroxycycloax-4(15)-ene(1),14-dehydroxyl daucucarotol(2),and one new rhamnofalane diterpenoid,2-hydroxy-3-dehydroxycaniojane(3),together with two known compounds,curcusone D(4) and curcusone C(5),were isolated from the roots of Jatropha curcas.The chemical structures of these compounds were established by chemical methods and extensive 1D-and 2D-NMR spectroscopic data analyses.  相似文献   

    10.
    4-Formyl-2-(2H-benzotriazol-2-yl)-phenol: an ESIPT chromophore   总被引:1,自引:0,他引:1  
    In the present work, excited state intramolecular proton transfer (ESIPT) emission properties of a new benzotriazole derivative 4-formyl-2-(2H-benzotriazol-2-yl)- phenol (C1) were studied. 4-Formyl-2-(2H-benzotriazol-2- yl)-methoxy-benzene (C2), 4-formyl-2-(2H-benzotriazol-2- yl)-phenyl acetate (C3) and 4-methyl-2-(2H-benzotriazol- 2-yl)-phenol (C4) were used as the reference molecules. ^1H NMR chemical shift of hydroxy group in C1 was located at more down field than that of C4 or p-hydroxy-benzaldehyde (C5), respectively. C1 showed two absorption bands in the range of 260-400 nm zones in various solvents, while C2 and C3 exhibited single absorption band. The equal molar mixtures of C2/C5 or C3/C5 showed single absorption band. C2 and C3 displayed single fluorescence emission band in various solvents, while C1 exhibited dual emission bands in some strong polar solvents. Furthermore, the second emission band in these strong polar solvents showed the large Stokes shift. The results show that the second emission band of C1 was produced by ESIPT. C2 and C3 could not undergo ESIPT due to no hydroxy group. The geometry optimization calculation of enol and keto forms in the ground and excited states of C1 provided tough theoretical evidences of ESIPT.  相似文献   

    11.
    Rare decays in flavor physics often suffer from Helicity suppress and Loop suppress. Helicity flip is a direct consequence of chiral \(U(3)\) symmetry breaking and electroweak symmetry breaking. The identical feature is also shared by the mass generation of SM fermions. In this review, we use the Minimal Supersymmetric Standard Model (MSSM) as an example to illustrate an explicit connection between bottom Yukawa coupling and rare decay process of \(b\rightarrow s\gamma \) . We take a symmetry approach to study the common symmetry breaking in supersymmetric correction to bottom quark mass generation and \(b\rightarrow s\gamma \) . We show that Large Peccei-Quinn symmetry breaking effect and \(R\) -symmetry breaking effect required by \(b\rightarrow s\gamma \) inevitably lead to significant reduction of bottom Yukawa \({y}_{b}\) . To compromise the reduction in \(b\bar{b}\) , a new decay is also needed to keep the Higgs total width as the SM value.  相似文献   

    12.
    The lighter chargino three body decays ~χ±1→~χ0 1ff ′ via the W^± boson and the charged Higgs boson H^± were studied in the R-parity conserved Minimal Supersymmetric Standard Model (MSSM). We treat ~χ±1 decays as production and decay of W^± and H^± i.e.,~χ±1→~χ01W^±(H^±) → χ0 1ff ′. Both higgsino- like and wino-like ~χ±1 decays were well investigated. These decays are calculated at 1-loop level and the loop corrections are found to be less than three percent. The signal of the charged Higgs H^± production from ~χ±1 decays is discussed. It will offer important information about the chargino and neutralino sector, as well as the charged Higgs sector in the MSSM.  相似文献   

    13.
    Two 1,3-alternate thiacalix[4]arene derivatives bearing amide groups, 1,3-alternate p-tert-butylthiacalix[4]arene tetraamide (4), and 1,3-alternate p-H-thiacalix[4]arene tetraamide (6) were prepared, and their crystal structures were determined by single-crystal X-ray diffraction method. The steric hindrances posed by tert-butyl groups play an important part in the synthesis and the self-assembly of the two compounds. Compound 6 was synthesized from the corresponding ester, which was obtained by the reaction of acid chloride with ammonia. In the crystal structure, compound 4 presents a highly symmetric molecular structure, while for compound 6, because of absence of tert-butyl groups, it presents a more flexible molecular structure.  相似文献   

    14.
    15.
    A series of iron(III)-containing imidazolium salts of the general formula [DRim][FeX4] (R = 2,6-diisopropylphenyl, IPr, X = Cl, 1; R = IPr, X = Br, 2; R = tertbutyl, t Bu, X = Cl, 3; R = isopropyl, i Pr, X = Cl, 4; R = benzyl, Bn, X = Cl, 5; R = Bn, X = Br, 6) have been prepared in high yields via reactions of anhydrous ferric halides with equivalent of the corresponding N,N-dihydrocarby-limidazolium halides, where 2–6 are novel ones. All of the complexes were characterized by elemental analysis, Raman spectroscopy, electrospray ionization mass spectroscopy, and X-ray crystallography for 1 and 2. All of them were non-hygroscopic and air-stable, with four of them existing as solids (1–4) and two as liquids (5 and 6) at room temperature. A preliminary catalytic study on the coupling of 4-tolylmagnesium bromide with cyclohexyl bromide revealed that 1 and 3 possessed the highest activity. In comparison, 2, 4 and 5 exhibited moderate activity and the least active complex was 6.  相似文献   

    16.
    The nonleptonic two body \(B_{u,d,s,c}\) decays involving a light tensor meson in final states are studied in the perturbative QCD approach based on \(k_{\mathrm{T}}\) factorization. The decay modes with a tensor meson emitted, are prohibited in naive factorization, since the emission diagram with a tensor meson produced from vacuum is vanished. While contributions from the so-called hard scattering emission diagrams and annihilation type diagrams are important and calculable in the perturbative QCD approach. The branching ratios of most decays are in the range of \(10^{-4}\) \(10^{-8}\) , which are bigger by 1 or 2 orders of magnitude than the predictions given by the naive factorization, but consistent with the predictions from the QCD factorization and the recent experimental measurements. We also give the predictions for the direct \(CP\) asymmetries, some of which are large enough for the future experiments to measure. We also find that, even with a small mixing angle, the mixing between \(f_2\) and \(f_2^{\prime }\) can bring remarkable changes to both branching ratios and the direct \(CP\) asymmetries for some decays involving \(f_2^{(\prime )}\) mesons. For decays with a vector meson and a tensor meson in final states, we predict a large percentage of transverse polarization contributions due to the contributions of the orbital angular momentum of the tensor mesons.  相似文献   

    17.
    Along with the running of Large Hadron Collider (LHC) located at CERN in November 2009, a large number of data samples of \(B_c\) meson have been collected and some hadronic \(B_c\) decay modes have been measured by the LHC experiments. In view of the special and important roles of \(B_c\) meson decays playing in the heavy flavor sector, we here give a short review on the status of two body hadronic decays \(B_c \rightarrow M_1 M_2\) at both experimental and theoretical aspects. For the theoretical progresses, specifically, we will show lots of theoretical studies on two body hadronic \(B_c\) decays involving pseudoscalar, vector, scalar, axial-vector, even tensor meson(s) in the final states by employing the perturbative QCD (pQCD) factorization approach. We will present a general analysis about the two-body hadronic decays of the heavy \(B_c\) meson and also provide some expectations for the future developments.  相似文献   

    18.
    The total column-averaged volume mixing ratio of atmospheric carbon dioxide (Xco2) has been retrieved with high spectral resolution solar absorption data obtained from ground-based Fourier transform spectrometer (FTS) measurements at Xichong, a coastal site in the district of Shenzhen in southern China. Based on differential optical absorption spectroscopy (DOAS) theory, the Xco2 was retrieved by finding the best match of observed high spectral resolution solar absorption data and monochromatic radia- tion transfer model calculations. The averaged Xco2 in the whole observation period was about 394.9 ppm. The uncertainty of the retrieval was estimated to be 2.0 ppm (0.51%) by comparing retrievals at two bands. The preliminary results show that Xc% retrieved by this method can be used to validate satellite remote sensing of Xco2.  相似文献   

    19.
    X-ray diffraction (XRD) was employed to analyze the texture evolution of commercial pure (CP) Ti during cold rolling and recrystallization annealing. The texture components were measured by electron backscattered diffraction (EBSD) after recrystallization annealing. The CP Ti tends to form a texture with the basal pole tilted 30°-40° away from the normal direction toward the transverse direction. The texture of the initial hot-rolled plate can be classified into three kinds, i.e., the pyramid texture (1013)[5230] and (2021)[1015], the basal plane texture (0001)[2110], and the stronger prism texture (1120)[0001]. After cold rolling and annealing (700℃, 60 min), the main texture components are the cold-rolled texture (1125)[1123] and the recrystallized texture (1013)[5230]. The texture (2021)[1015] is inherited from the texture of the initial hot-rolled plate with the decrease of orientation density gradually. The volume contents of the cold-rolled texture {2115} <0110> and the recrystallized texture {1013} <1210> are calculated by EBSD. After recrystallization annealing, the specimen is rich in the recrystallized texture and inherits some of texture components from the cold-rolled texture. When the annealing time is prolonged, the anisotropic value decreases.  相似文献   

    20.
    Two novel zinc Schiff-base complexes, bis-(N-(2-hydroxybenzidene)-p-aminodimethylaniline)zinc(II) (2) and bis-(N-(2-hydroxy-1-naphthidene)-p-aminodimethylaniline)zinc(II) (4) were designed and synthesized. Both the complexes exhibit good solubility in organic solvents and excellent thermal stabilities. A single crystal of 2 was grown and its crystalline structure was determined from X-ray diffraction data. Analysis of the electronic structures of both the zinc complexes calculated by density functional theory reveals a localization of orbital. The UV-Vis absorption and photoluminescence profiles of 4 in thin film are similar to those of 2, but the emission for 4 is red-shifted compared to 2. Three-layered devices with a configuration of ITO/NPB/2/Alq 3 /LiF/Al and ITO/NPB/4/Alq 3 /LiF/Al show a yellow and red emission, respectively.  相似文献   

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