6,938 research outputs found

    Effects of land incremental value allocation on rural operational construction land (ROCL) under market mechanism: case study in China

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    The use of the market mechanism to convert the rural operational construction land (ROCL) into urban construction land without ownership changes is currently being introduced into reform pilot projects in China, changing the only form of governmental expropriation in the past. The new system allows rural collective economic organizations and members of the rural collective economy to directly participate in the allocation of land incremental value increases due to changes in land use. This replaces the previous way of allocating only the original use compensation from the government. This paper investigates the collectively owned new system, to establish the positive effects and shortcoming of the new model. Three cases are applied for the analysis using inductive-deductive reasoning methodology based on the property right and landrent theories. We have found that local government land adjustment charges on the transactions of rural construction land are suggested to be from 16 to 20 percent. The share ownership quantification model (SOQM) of land incremental value allocation between the collective economic organizations and members is effective and beneficial to the development of the rural collective economy and its members

    Longitudinal Schottky spectra of a bunched Ne10+ ion beam at the CSRe

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    The longitudinal Schottky spectra of a radio-frequency (RF) bunched and electron cooled 22Ne10+ ion beam at 70 MeV/u have been studied by a newly installed resonant Schottky pick-up at the experimental cooler storage ring (CSRe), at IMP. For an RF-bunched ion beam, a longitudinal momentum spread of has been reached with less than 107 stored ions. The reduction of momentum spread compared with coasting ion beam was observed from Schottky noise signal of the bunched ion beam. In order to prepare the future laser cooling experiment at the CSRe, the RF-bunching power was modulated at 25th, 50th and 75th harmonic of the revolution frequency, effective bunching amplitudes were extracted from the Schottky spectrum analysis. Applications of Schottky noise for measuring beam lifetime with ultra-low intensity of ion beams are presented, and it is relevant to upcoming experiments on laser cooling of relativistic heavy ion beams and nuclear physics at the CSRe.Comment: to be published in Chinese Physics

    Descending motor circuitry required for NT-3 mediated locomotor recovery after spinal cord injury in mice

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    Locomotor function, mediated by lumbar neural circuitry, is modulated by descending spinal pathways. Spinal cord injury (SCI) interrupts descending projections and denervates lumbar motor neurons (MNs). We previously reported that retrogradely transported neurotrophin-3 (NT-3) to lumbar MNs attenuated SCI-induced lumbar MN dendritic atrophy and enabled functional recovery after a rostral thoracic contusion. Here we functionally dissected the role of descending neural pathways in response to NT-3-mediated recovery after a T9 contusive SCI in mice. We find that residual projections to lumbar MNs are required to produce leg movements after SCI. Next, we show that the spared descending propriospinal pathway, rather than other pathways (including the corticospinal, rubrospinal, serotonergic, and dopaminergic pathways), accounts for NT-3-enhanced recovery. Lastly, we show that NT-3 induced propriospino-MN circuit reorganization after the T9 contusion via promotion of dendritic regrowth rather than prevention of dendritic atrophy

    Emergence of non-centrosymmetric topological insulating phase in BiTeI under pressure

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    The spin-orbit interaction affects the electronic structure of solids in various ways. Topological insulators are one example where the spin-orbit interaction leads the bulk bands to have a non-trivial topology, observable as gapless surface or edge states. Another example is the Rashba effect, which lifts the electron-spin degeneracy as a consequence of spin-orbit interaction under broken inversion symmetry. It is of particular importance to know how these two effects, i.e. the non-trivial topology of electronic states and Rashba spin splitting, interplay with each other. Here we show, through sophisticated first-principles calculations, that BiTeI, a giant bulk Rashba semiconductor, turns into a topological insulator under a reasonable pressure. This material is shown to exhibit several unique features such as, a highly pressure-tunable giant Rashba spin splitting, an unusual pressure-induced quantum phase transition, and more importantly the formation of strikingly different Dirac surface states at opposite sides of the material.Comment: 5 figures are include

    Syphilis-attributable adverse pregnancy outcomes in China: a retrospective cohort analysis of 1187 pregnant women with different syphilis treatment.

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    BACKGROUND: Syphilis is responsible for a substantial burden of preventable adverse outcomes in pregnancy. The purpose of this study was to compare the frequency of adverse pregnancy outcomes among syphilis-seropositive women who received different treatment regimens at different times in Guangzhou, China. METHODS: Pregnant women with syphilis infection who received prenatal and delivery services in Guangzhou between January 2014 and December 2016 were included. Association between treatment status and the composite adverse outcomes (preterm birth, infant smaller than gestational age, stillbirth, and spontaneous abortion) was estimated. RESULTS: Of 1187 syphilis-seropositive pregnant women included in the analysis, 900 (75.8%) syphilis-seropositive pregnant women received treatment, and 287(24.2%) did not receive treatment. Adverse pregnancy outcomes were observed among 16.3% (147/900) of women with treatment and 33.8% (97/287) of women without treatment. Syphilis-seropositive pregnant women treated with one or two courses of penicillin had a similar risk of adverse pregnancy outcomes (adjusted RR = 1.36, 95% CI: 0.94-1.96). Adverse outcomes were more common among women whose non-treponemal serum test titer was >1:8 and received treatment after 28 weeks compared to before 28 weeks (adjusted RR = 2.34, 95% CI: 1.22-4.48). CONCLUSIONS: Women who received one course of penicillin and women who received two courses of penicillin had a similar risk of adverse pregnancy outcomes. Syphilis treatment before 28 weeks of pregnancy is critical. Strategies to promote high-quality prenatal services are needed

    Study of J/ψJ/\psi and ψ(3686)Σ(1385)0Σˉ(1385)0\psi(3686)\rightarrow\Sigma(1385)^{0}\bar\Sigma(1385)^{0} and Ξ0Ξˉ0\Xi^0\bar\Xi^{0}

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    We study the decays of J/ψJ/\psi and ψ(3686)\psi(3686) to the final states Σ(1385)0Σˉ(1385)0\Sigma(1385)^{0}\bar\Sigma(1385)^{0} and Ξ0Ξˉ0\Xi^0\bar\Xi^{0} based on a single baryon tag method using data samples of (1310.6±7.0)×106(1310.6 \pm 7.0) \times 10^{6} J/ψJ/\psi and (447.9±2.9)×106(447.9 \pm 2.9) \times 10^{6} ψ(3686)\psi(3686) events collected with the BESIII detector at the BEPCII collider. The decays to Σ(1385)0Σˉ(1385)0\Sigma(1385)^{0}\bar\Sigma(1385)^{0} are observed for the first time. The measured branching fractions of J/ψJ/\psi and ψ(3686)Ξ0Ξˉ0\psi(3686)\rightarrow\Xi^0\bar\Xi^{0} are in good agreement with, and much more precise, than the previously published results. The angular parameters for these decays are also measured for the first time. The measured angular decay parameter for J/ψΣ(1385)0Σˉ(1385)0J/\psi\rightarrow\Sigma(1385)^{0}\bar\Sigma(1385)^{0}, α=0.64±0.03±0.10\alpha =-0.64 \pm 0.03 \pm 0.10, is found to be negative, different to the other decay processes in this measurement. In addition, the "12\% rule" and isospin symmetry in the J/ψJ/\psi and ψ(3686)ΞΞˉ\psi(3686)\rightarrow\Xi\bar\Xi and Σ(1385)Σˉ(1385)\Sigma(1385)\bar{\Sigma}(1385) systems are tested.Comment: 11 pages, 7 figures. This version is consistent with paper published in Phys.Lett. B770 (2017) 217-22

    Observation of an anomalous line shape of the ηπ+π\eta^{\prime}\pi^{+}\pi^{-} mass spectrum near the ppˉp\bar{p} mass threshold in J/ψγηπ+πJ/\psi\rightarrow\gamma\eta^{\prime}\pi^{+}\pi^{-}

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    Using 1.09×1091.09\times10^{9} J/ψJ/\psi events collected by the BESIII experiment in 2012, we study the J/ψγηπ+πJ/\psi\rightarrow\gamma\eta^{\prime}\pi^{+}\pi^{-} process and observe a significant abrupt change in the slope of the ηπ+π\eta^{\prime}\pi^{+}\pi^{-} invariant mass distribution at the proton-antiproton (ppˉp\bar{p}) mass threshold. We use two models to characterize the ηπ+π\eta^{\prime}\pi^{+}\pi^{-} line shape around 1.85 GeV/c21.85~\text{GeV}/c^{2}: one which explicitly incorporates the opening of a decay threshold in the mass spectrum (Flatt\'{e} formula), and another which is the coherent sum of two resonant amplitudes. Both fits show almost equally good agreement with data, and suggest the existence of either a broad state around 1.85 GeV/c21.85~\text{GeV}/c^{2} with strong couplings to ppˉp\bar{p} final states or a narrow state just below the ppˉp\bar{p} mass threshold. Although we cannot distinguish between the fits, either one supports the existence of a ppˉp\bar{p} molecule-like state or bound state with greater than 7σ7\sigma significance

    Measurements of absolute hadronic branching fractions of Λc+\Lambda_{c}^{+} baryon

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    Using 567pb1567\rm{pb}^{-1} of e+ee^+e^- collisions recorded at s=4.599GeV\sqrt{s}=4.599\rm{GeV} with the BESIII detector, we report first measurements of absolute hadronic branching fractions of Cabibbo-favored decays of the Λc+\Lambda_{c}^{+} baryon with a double-tag technique. A global least-square fitter is utilized to improve the measured precision. Among the measurements for twelve Λc+\Lambda_{c}^{+} decay modes, the branching fraction for Λc+pKπ+\Lambda_{c}^{+} \rightarrow pK^-\pi^+ is determined to be (5.84±0.27±0.23)%(5.84\pm0.27\pm0.23)\%, where the first uncertainty is statistical and the second is systematic. In addition, the measurements of the branching fractions of the other eleven Cabbibo-favored hadronic decay modes are significantly improved
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