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111.
《Pramana》2003,60(5):921-931
The PHOBOS detector has been used to study Au + Au collisions at√sNN = 56,130, and 200 GeV Several global observables have been measured and the results are compared with theoretical models.
These observables include the charged-particle multiplicity measured as a function of beam energy, pseudo-rapidity, and centrality
of the collision. A unique feature of the PHOBOS detector is its almost complete angular coverage such that these quantities
can be studied over a pseudo-rapidity interval of |η|≤5.4. This allows for an almost complete integration of the total charged
particle yield, which is found to be about N
ch
tot
= 4200 ±470 at √sNN = 130 GeV and N
ch
tot
= 5300 ±530 at √sNN = 200 GeV.
The ratio of anti-particles to particles emitted in the mid-rapidity region has also been measured using the PHOBOS magnetic
spectrometer. Of particular interest is the ratio of anti-protons to protons in the mid-rapidity region, which was found to
be (i.e.921-1) at √sNN = 130 GeV. This high value suggests that an almost baryon-free region has been produced in the collisions. 相似文献
112.
用扩散模型研究了壳对幻数附近的核,即204Pb,208Pb,212Pb和128Sn,132Sn,136Sn,在裂变过程中蒸发轻粒子多重性的影响.发现壳能够影响粒子发射的同位旋依赖性,并且该影响的大小与复合系统的自旋和激发能有关.计算表明角动量在壳影响同位旋相关的粒子发射中起到了显著的作用,而高激发能弱化了壳的影响. 相似文献
113.
Wojciech Chojnacki 《Letters in Mathematical Physics》1991,22(1):7-10
We prove that every eigenvalue of a Schrödinger operator with an almost periodic potential acting in the space of all square Haar-integrable functions on the Bohr compactification of has multiplicity not greater than 2. 相似文献
114.
The excitation functions of the evaporation residue formation probability of three heavy nuclei 194Pb, 200Pb and 206Pb are calculated by using a Langevin equation coupled with a statistical decay model.The results show that the neutron-to-proton ratio (N/Z) of a compound nucleus has an effect on survival probability and this effect becomes larger with increasing N/Z. This is because the fission barrier and the pre-saddle particle emission depend on the N/Z ratio of the system. 相似文献
115.
116.
An Ambrosetti-Prodi type exact multiplicity result is proved for a diffusive logistic equation with harvesting. We show that a modified diffusive logistic mapping has exactly either zero, or one, or two pre-images depending on the harvesting rate. It implies that the original diffusive logistic equation with harvesting has at most two positive steady state solutions. 相似文献
117.
118.
《代数通讯》2013,41(5):2053-2065
Abstract We consider the group G of C-automorphisms of C(x, y) (resp. C[x, y]) generated by s, t such that t(x) = y, t(y) = x and s(x) = x, s(y) = ? y + u(x) where u ∈ C[x] is of degree k ≥ 2. Using Galois's theory, we show that the invariant field and the invariant algebra of G are equal to C. 相似文献
119.
Karlheinz Hafner 《Numerical Functional Analysis & Optimization》2013,34(3-4):415-433
This paper focusses on quasilinear second order differential operators. Concerning their strong monotonicity and Lipschitz continuity sufficient conditions are stated which are both explicit and easy to show. Applying these functional analytic properties to nonlinear obstacle problems we prove error estimates in energy norm for the finite element method with linear trial functions. 相似文献
120.
Raffaele Chiappinelli 《Journal of Mathematical Analysis and Applications》2009,354(1):263-3777
We prove upper and lower bounds on the eigenvalues and discuss their asymptotic behaviour (as the norm of the eigenvector tends to zero) in bifurcation problems from the line of trivial solutions, considering perturbations of linear self-adjoint operators in a Hilbert space. The proofs are based on the Lyapounov-Schmidt reduction. The results are applied to a class of semilinear elliptic operators in bounded domains of RN and in particular to Sturm-Liouville operators. 相似文献