408 research outputs found

    Китай: на пути к новой налоговой реформе

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    В результате налоговой реформы 1994 г. в Китае была создана современная налоговая система, обеспечившая плавный переход от старой налоговой системы к рыночной. В настоящее время значительные изменения внутренней и внешней среды ставят перед налоговой системой новые, серьезные задачи. Если прежде основной целью было «создание базовой структуры налоговой системы, соответствующей социалистической рыночной экономике», то спустя 20 лет это «движение к современной налоговой системе в рамках модернизации национальной административной системы». В статье подробно описываются причины и направления современных преобразований в налоговой системе. Анализ сложившейся структуры доходов бюджета позволил сделать выводы о сохранившемся влиянии принципов плановой экономики, так как значительную часть составляют неналоговые доходы и отчисления от прибыли государственных предприятий, а в налоговых доходах преобладают налоги на потребление. Кроме того, до настоящего времени налоговое бремя зависит не от налогового законодательства, а от ежегодно формируемых планов по сбору налогов. Таким образом, выявлены основные предпосылки современной налоговой реформы: обеспечение социальной справедливости становится приоритетной целью государственной политики; меняется структура экономики и тип экономического развития; продолжается рост налогового бремени; уровень налогового администрирования отстает от современных требований к управлению. Основными целями проводимых реформ являются: поддержание стабильности налогового бремени на макроуровне; снижение доли косвенных налогов путем расширения круга плательщиков НДС, упрощение ставок и изменение порядка распределения налога между бюджетами различных уровней; значительное увеличение доли прямых налогов за счет личного подоходного налога и налога на квартиры. Однако все эти изменения требуют адекватного совершенствования налогового администрирования, так как переход к налогообложению индивидуальных налогоплательщиков не возможен без изменения строения и функций налоговых органов.China’s existing tax system was established via the famous comprehensive fiscal reform conducted in 1994. In the next 20 years a series of incremental measures have been taken to improve this tax system framework. However, along with the increasingly deepened economic reform process, both outside and inside environments and the constrain condition facing the tax system have changed greatly. People have new adequate expectations for the tax policy. Responding to this changing circumstance, the direction of the tax system reform has undergone a fundamental change with its goal switching from «establishing the basic framework of the tax system suitable to the socialist market economy» to «establishing the modern tax regime in line with the modernization of the national administration system and administration capability» since the Third Plenary Session of the 18th Central Committee of the Communist Party of China (CCCPC) on November 12, 2013. Against this background, we comprehensively analyze the causes, main contents, focuses, supporting measures and enforcement roadmaps of this fundamental tax reform

    Dilepton production in proton-proton collisions at BEVALAC energies

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    The dilepton production in elementary ppe+eX{pp\to e^{+}e^{-}X} reactions at BEVALAC energies Tlab=1÷5T_{lab}=1\div 5 GeV is investigated. The calculations include direct e+e{e^{+}e^{-}} decays of the vector mesons ρ0\rho ^{0}, ω\omega , and ϕ\phi , Dalitz decays of the π0\pi ^{0}-, η\eta -, % \rho -, ω\omega -, and ϕ\phi -mesons, and of the baryon resonances % \Delta (1232),N(1520), ...... . The subthreshold vector meson production cross sections in pppp collisions are treated in a way sufficient to avoid double counting with the inclusive vector meson production. The vector meson dominance model for the transition form factors of the resonance Dalitz decays Re+eNR\to e^{+}e^{-}N is used in an extended form to ensure correct asymptotics which are in agreement with the quark counting rules. Such a modification gives an unified and consistent description of both RNγR\to N\gamma radiative decays and RNρ(ω)R\to N\rho (\omega) meson decays. The effect of multiple pion production on the experimental efficiency for the detection of the dilepton pairs is studied. We find the dilepton yield in reasonable agreement with the experimental data for the set of intermediate energies whereas at the highest energy Tlab=4.88T_{lab}=4.88 GeV the number of dilepton pairs is likely to be overestimated experimentally in the mass range M=300÷700M=300\div 700 MeV.Comment: 25 pages (IOP style), 5 figures, revised manuscript accepted for publication in JP

    Phase-space dependence of particle-ratio fluctuations in Pb+Pb collisions from 20A to 158A GeV beam energy

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    A novel approach, the identity method, was used for particle identification and the study of fluctuations of particle yield ratios in Pb+Pb collisions at the CERN Super Proton Synchrotron (SPS). This procedure allows to unfold the moments of the unknown multiplicity distributions of protons (p), kaons (K), pions (π\pi) and electrons (e). Using these moments the excitation function of the fluctuation measure νdyn\nu_{\text{\text{dyn}}}[A,B] was measured, with A and B denoting different particle types. The obtained energy dependence of νdyn\nu_{\text{dyn}} agrees with previously published NA49 results on the related measure σdyn\sigma_{\text{dyn}}. Moreover, νdyn\nu_{\text{dyn}} was found to depend on the phase space coverage for [K,p] and [K,π\pi] pairs. This feature most likely explains the reported differences between measurements of NA49 and those of STAR in central Au+Au collisions

    Production of deuterium, tritium, and 3^3He in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV at the CERN SPS

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    Production of dd, tt, and 3^3He nuclei in central Pb+Pb interactions was studied at five collision energies (sNN=\sqrt{s_{NN}}= 6.3, 7.6, 8.8, 12.3, and 17.3 GeV) with the NA49 detector at the CERN SPS. Transverse momentum spectra, rapidity distributions, and particle ratios were measured. Yields are compared to predictions of statistical models. Phase-space distributions of light nuclei are discussed and compared to those of protons in the context of a coalescence approach. The coalescence parameters B2B_2 and B3B_3, as well as coalescence radii for dd and 3^3He were determined as a function of transverse mass at all energies.Comment: 22 pages, 29 figures, 8 tables, for submission to Phys. Rev.

    Measurement of event-by-event transverse momentum and multiplicity fluctuations using strongly intensive measures Δ[PT,N]\Delta[P_T, N] and Σ[PT,N]\Sigma[P_T, N] in nucleus-nucleus collisions at the CERN Super Proton Synchrotron

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    Results from the NA49 experiment at the CERN SPS are presented on event-by-event transverse momentum and multiplicity fluctuations of charged particles, produced at forward rapidities in central Pb+Pb interactions at beam momenta 20AA, 30AA, 40AA, 80AA, and 158AA GeV/c, as well as in systems of different size (p+pp+p, C+C, Si+Si, and Pb+Pb) at 158AA GeV/c. This publication extends the previous NA49 measurements of the strongly intensive measure ΦpT\Phi_{p_T} by a study of the recently proposed strongly intensive measures of fluctuations Δ[PT,N]\Delta[P_T, N] and Σ[PT,N]\Sigma[P_T, N]. In the explored kinematic region transverse momentum and multiplicity fluctuations show no significant energy dependence in the SPS energy range. However, a remarkable system size dependence is observed for both Δ[PT,N]\Delta[P_T, N] and Σ[PT,N]\Sigma[P_T, N], with the largest values measured in peripheral Pb+Pb interactions. The results are compared with NA61/SHINE measurements in p+pp+p collisions, as well as with predictions of the UrQMD and EPOS models.Comment: 12 pages, 14 figures, to be submitted to PR

    Proton -- Lambda Correlations in Central Pb+Pb Collisions at sqrt(s_{NN}) = 17.3 GeV

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    The momentum correlation between protons and lambda particles emitted from central Pb+Pb collisions at sqrt(s_{NN}) = 17.3 GeV was studied by the NA49 experiment at the CERN SPS. A clear enhancement is observed for small relative momenta (q_{inv} < 0.2 GeV). By fitting a theoretical model, which uses the strong interaction between the proton and the lambda in a given pair, to the measured data a value for the effective source size is deduced. Assuming a static Gaussian source distribution we derive an effective radius parameter of R_G = 3.02 \pm 0.20$(stat.)^{+0.44}_{-0.16}(syst.) fm.Comment: 14 pages, 9 figures, submitted to Phys. Rev.

    Antideuteron and deuteron production in mid-central Pb+Pb collisions at 158AA GeV

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    Production of deuterons and antideuterons was studied by the NA49 experiment in the 23.5% most central Pb+Pb collisions at the top SPS energy of sNN\sqrt{s_{NN}}=17.3 GeV. Invariant yields for dˉ\bar{d} and dd were measured as a function of centrality in the center-of-mass rapidity range 1.2<y<0.6-1.2<y<-0.6. Results for dˉ(d)\bar{d}(d) together with previously published pˉ(p)\bar{p}(p) measurements are discussed in the context of the coalescence model. The coalescence parameters B2B_2 were deduced as a function of transverse momentum ptp_t and collision centrality.Comment: 9 figure

    Energy dependence of kaon-to-proton ratio fluctuations in central Pb+Pb collisions from sNN\sqrt{s_{NN}} = 6.3 to 17.3 GeV

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    Kaons and protons carry large parts of two conserved quantities, strangeness and baryon number. It is argued that their correlation and thus also fluctuations are sensitive to conditions prevailing at the anticipated parton-hadron phase boundary. Fluctuations of the (K++K)/(p+pˉ)(\mathrm{K}^+ + \mathrm{K}^-)/(\mathrm{p}+\bar{\mathrm{p}}) and K+/p\mathrm{K}^+/\mathrm{p} ratios have been measured for the first time by NA49 in central Pb+Pb collisions at 5 SPS energies between sNN\sqrt{s_{NN}}= 6.3 GeV and 17.3 GeV. Both ratios exhibit a change of sign in σdyn\sigma_{\mathrm{dyn}}, a measure of non-statistical fluctuations, around sNN\sqrt{s_{NN}} = 8 GeV. Below this energy, σdyn\sigma_{\mathrm{dyn}} is positive, indicating higher fluctuation compared to a mixed event background sample, while for higher energies, σdyn\sigma_{\mathrm{dyn}} is negative, indicating correlated emission of kaons and protons. The results are compared to UrQMD calculations which which give a good description at the higher SPS energies, but fail to reproduce the transition to positive values.Comment: 5 pages, 4 figure

    Search for the QCD critical point in nuclear collisions at the CERN SPS

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    Pion production in nuclear collisions at the SPS is investigated with the aim to search, in a restricted domain of the phase diagram, for power-laws in the behavior of correlations which are compatible with critical QCD. We have analyzed interactions of nuclei of different size (p+p, C+C, Si+Si, Pb+Pb) at 158AA GeV adopting, as appropriate observables, scaled factorial moments in a search for intermittent fluctuations in transverse dimensions. The analysis is performed for π+π\pi^+\pi^- pairs with invariant mass very close to the two-pion threshold. In this sector one may capture critical fluctuations of the sigma component in a hadronic medium, even if the σ\sigma-meson has no well defined vacuum state. It turns out that for the Pb+Pb system the proposed analysis technique cannot be applied without entering the invariant mass region with strong Coulomb correlations. As a result the treatment becomes inconclusive in this case. Our results for the other systems indicate the presence of power-law fluctuations in the freeze-out state of Si+Si approaching in size the prediction of critical QCD.Comment: 31 pages, 11 figure
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