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801.
In contrast to the binary liquids, the order-parameter relaxation rates in the pure fluids are greatly affected by a large non-critical component. With the appropriate crossover correction to dynamic scaling, we restore universality and demonstrate that the ultrasonic data for both the one- and two-component fluids fall on the same scaling plot. 相似文献
802.
We study the unzipping of double stranded DNA by applying a pulling force at a fraction s (0< or =s < or =1) from the anchored end. From exact analytical and numerical results, the complete phase diagram is presented. The phase diagram shows a strong ensemble dependence for various values of s. In addition, we show the existence of an eye phase and a triple point. 相似文献
803.
Abazov VM Abbott B Abolins M Acharya BS Adams DL Adams M Adams T Agelou M Agram JL Ahmed SN Ahn SH Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anderson S Andrieu B Arnoud Y Askew A Asman B Autermann C Avila C Babukhadia L Bacon TC Baden A Baffioni S Baldin B Balm PW Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Beaudette F Begel M Beri SB Bernardi G Bertram I Besançon M Besson A Beuselinck R Bezzubov VA Bhat PC Bhatnagar V 《Physical review letters》2004,93(16):162002
We report the observation of the X(3872) in the J/psipi(+)pi(-) channel, with J/psi decaying to mu(+)mu(-), in pp collisions at sqrt[s]=1.96 TeV. Using approximately 230 pb(-1) of data collected with the Run II D0 detector, we observe 522+/-100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9+/-3.1(stat)+/-3.0(syst) MeV/c(2). We have investigated the production and decay characteristics of the X(3872) and find them to be similar to those of the psi(2S) state. 相似文献
804.
B. Bhattacharjee P. Lemonidis W.H. Green Jr. P.I. Barton 《Mathematical Programming》2005,103(2):283-307
Optimization problems involving a finite number of decision variables and an infinite number of constraints are referred to as semi-infinite programs (SIPs). Existing numerical methods for solving nonlinear SIPs make strong assumptions on the properties of the feasible set, e.g., convexity and/or regularity, or solve a discretized approximation which only guarantees a lower bound to the true solution value of the SIP. Here, a general, deterministic algorithm for solving semi-infinite programs to guaranteed global optimality is presented. A branch-and-bound (B&B) framework is used to generate convergent sequences of upper and lower bounds on the SIP solution value. The upper-bounding problem is generated by replacing the infinite number of real-valued constraints with a finite number of constrained inclusion bounds; the lower-bounding problem is formulated as a convex relaxation of a discretized approximation to the SIP. The SIP B&B algorithm is shown to converge finitely to –optimality when the subdivision and discretization procedures used to formulate the node subproblems are known to retain certain convergence characteristics. Other than the properties assumed by globally-convergent B&B methods (for finitely-constrained NLPs), this SIP algorithm makes only one additional assumption: For every minimizer x* of the SIP there exists a sequence of Slater points xn for which (cf. Section 5.4). Numerical results for test problems in the SIP literature are presented. The exclusion test and a modified upper-bounding problem are also investigated as heuristic approaches for alleviating the computational cost of solving a nonlinear SIP to guaranteed global optimality. 相似文献
805.
806.
Abazov VM Abbott B Abolins M Acharya BS Adams DL Adams M Adams T Agelou M Agram JL Ahmed SN Ahn SH Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anderson S Andrieu B Arnoud Y Askew A Asman B Atramentov O Autermann C Avila C Babukhadia L Bacon TC Baden A Baffioni S Baldin B Balm PW Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Beaudette F Begel M Bellavance A Beri SB Bernardi G Bernhard R Bertram I Besançon M Besson A 《Physical review letters》2005,94(4):041801
We report the results of a search for supersymmetry (SUSY) with gauge-mediated breaking in the missing transverse energy distribution of inclusive diphoton events using 263 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2004. No excess is observed above the background expected from standard model processes, and lower limits on the masses of the lightest neutralino and chargino of about 108 and 195 GeV, respectively, are set at the 95% confidence level. These are the most stringent limits to date for models with gauge-mediated SUSY breaking with a short-lived neutralino as the next-to-lightest SUSY particle. 相似文献
807.
Indranil?Chakraborty Satya?P.?MoulikEmail author 《Journal of nanoparticle research》2005,7(2-3):237-247
Colloidal nanodispersion of lead sulfide has been prepared in the aqueous compartments of water/AOT/n-heptane. Compartmentalization has prevented growth and coagulation of particles in the dispersion. The uv–vis and fluorescence spectral measurements of the colloidal PbS dispersion were taken. Particle size has been determined by laser light scattering, transmission electron microscopy and absorption spectroscopy. The effects of temperature, ω (water/AOT mole ratio), [AOT], and [PbS] on the particle size have been examined. The nanodispersed particles in microemulsion capped with thiophenol and dodecanethiol were isolated and characterized by the TEM and FTIR methods.This revised version was published online in August 2005 with a corrected issue number. 相似文献
808.
809.
We study the local density of vibrational states of a disordered binary chain using a renormalization approach suitable for the alloy problem. We include isotopic and spring constant disorder. Short range order effects in the alloy are taken into account in the pair approximation. We present some numerical results for the case of spring constant disorder and discuss their relevance for the interpretation of neutron scattering experiments in some metallic amorphous systems. 相似文献
810.
Let X be an irreducible smooth projective curve over an algebraically closed field k of positive characteristic and G a simple linear algebraic group over k. Fix a proper parabolic subgroup P of G and a nontrivial anti-dominant character λ of P. Given a principal G-bundle EG over X, let EG(λ) be the line bundle over EG/P associated to the principal P-bundle EG→EG/P for the character λ. We prove that EG is strongly semistable if and only if the line bundle EG(λ) is numerically effective. For any connected reductive algebraic group H over k, a similar criterion is proved for strongly semistable H-bundles. 相似文献