Enhanced heat transport by turbulent two-phase Rayleigh-B\'enard convection

We report measurements of turbulent heat-transport in samples of ethane (C$_2$H$_6$) heated from below while the applied temperature difference $\Delta T$ straddled the liquid-vapor co-existance curve $T_\phi(P)$. When the sample top temperature $T_t$ decreased below $T_\phi$, droplet condensation occurred and the latent heat of vaporization $H$ provided an additional heat-transport mechanism.The effective conductivity $\lambda_{eff}$ increased linearly with decreasing $T_t$, and reached a maximum value $\lambda_{eff}^*$ that was an order of magnitude larger than the single-phase $\lambda_{eff}$. As $P$ approached the critical pressure, $\lambda_{eff}^*$ increased dramatically even though $H$ vanished. We attribute this phenomenon to an enhanced droplet-nucleation rate as the critical point is approached.Comment: 4 gages, 6 figure

Production of f0(1710)f_0(1710), f0(1500)f_0(1500), and f0(1370)f_0(1370) in J/ψJ/\psi hadronic decays

A coherent study of the production of $f_0^i$ ($i=1$, 2, 3 corresponding to $f_0(1710)$, $f_0(1500)$, and $f_0(1370)$) in $J/\psi\to V f_0 \to V PP$ is reported based on a previously proposed glueball and $Q\bar{Q}$ nonet mixing scheme, and a factorization for the decay of $J/\psi\to V f_0^i$, where $V$ denotes the isoscalar vector mesons $\phi$ and $\omega$, and $P$ denotes pseudoscalar mesons. The results show that the $J/\psi$ decays are very sensitive to the structure of those scalar mesons, and suggest a glueball in the $1.5-1.7$ GeV region, in line with Lattice QCD. The presence of significant glueball mixings in the scalar wavefunctions produces peculiar patterns in the branching ratios for $J/\psi\to V f_0^i\to VPP$, which are in good agreement with the recently published experimental data from the BES collaboration.Comment: Version accepted by PRD; Numerical results in Tab IV and VI changed due to correction of an error in quoting an experimental datum; Conclusion is not change

Transitions between turbulent states in rotating Rayleigh-Benard convection

Weakly-rotating turbulent Rayleigh-Benard convection was studied experimentally and numerically. With increasing rotation and large enough Rayleigh number an abrupt transition from a turbulent state with nearly rotation-independent heat transport to another turbulent state with enhanced heat transfer is observed at a critical inverse Rossby number $1/Ro_c \simeq 0.4$. Whereas for $1/Ro < 1/Ro_c$ the strength of the large-scale convection-roll is either enhanced or essentially unmodified depending on parameters, its strength is increasingly diminished beyond $1/Ro_c$ where it competes with Ekman vortices that cause vertical fluid transport and thus heat-transfer enhancement.Comment: 5 pages, 4 figure

High relative risk of all-cause mortality attributed to smoking in China: Guangzhou Biobank Cohort Study

Prediction of disease burden in China arising from smoking based on earlier cohorts in the West and China could not reflect the disease burden at the current stage accurately. No cohort studies in China focused specifically on people born since 1950. We examined the risk of all-cause mortality attributed to smoking in adults in Guangzhou, the city with the most rapidly expanding economy in China.This population-based prospective cohort included 21,658 women and 8,284 men aged 50+ years enrolled from 2003-2008 and followed until January 2016. During an average follow-up of 8.8 (standard deviation = 1.8) years, 2,986 (1,586 women, 1,400 men) deaths were recorded. After adjustment for confounders, the hazards ratios (95% confidence interval (CI)) of all-cause mortality in current versus never smokers increased from 1.61 (95% CI 1.45-1.80) in those born in 1920-1939 to 2.02 (95% CI 1.74-2.34), and 4.40 (95% CI 3.14-6.17), in those born in the 1940s and 1950s, respectively (P for trend 0.009).In smokers born after 1949 in Guangzhou and other areas which have the longest history of smoking, the mortality risk could have reached three fold that of non-smokers, as in the UK, US and Australia. If confirmed, unless China quickly and strictly complies with the WHO Framework Convention on Tobacco Control with massive smoking cessation in the population, this is a more striking warning that China will be facing an even larger disease burden from tobacco use than previous forecasts

Molecular identification of Clonorchis sinensis and discrimination with other opisthorchid liver fluke species using multiple Ligation-depended Probe Amplification (MLPA)

<p>Abstract</p> <p>Background</p> <p>Infections with the opisthorchid liver flukes <it>Clonorchis sinensis</it>, <it>Opisthorchis viverrini</it>, and <it>O. felineus </it>cause severe health problems globally, particularly in Southeast Asia. Early identification of the infection is essential to provide timely and appropriate chemotherapy to patients.</p> <p>Results</p> <p>In this study we evaluate a PCR-based molecular identification method, Multiplex Ligation-dependent Probe Amplification (MLPA), which allows rapid and specific detection of single nucleotide acid differences between <it>Clonorchis sinensis</it>, <it>Opisthorchis viverrini </it>and <it>O. felineus</it>. Three probe pairs were derived from the Internally Transcribed Spacer 1 (ITS1) of three opisthorchid liver flukes using a systematic phylogenetic analysis. Specific loci were detected in all three species, yielding three amplicons with 198,172 and 152 bp, respectively, while no cross reactions were observed. A panel of 66 <it>C. sinensis </it>isolates was screened using MLPA. All species were positively identified, and no inhibition was observed. The detection limit was 10³copies of the ITS gene for the three liver flukes, or about 60 pg genomic DNA for <it>Clonorchis sinensis</it>. Amplification products can be detected by electrophoresis on agarose gel or in a capillary sequencer. In addition, genomic DNA of <it>Clonorchis sinensis </it>in fecal samples of infected rats was positively amplified by MLPA.</p> <p>Conclusion</p> <p>The flexibility and specificity make MLPA a potential tool for specific identification of infections by opisthorchid liver flukes in endemic areas.</p

Nuclear Stopping as A Probe to In-medium Nucleon-nucleon Cross Section in Intermediate Energy Heavy Ion Collisions

Using an isospin-dependent quantum molecular dynamics, nuclear stopping in intermediate heavy ion collisions has been studied. The calculation has been done for colliding systems with different neutron-proton ratios in beam energy ranging from 15MeV/u to 150MeV/u. It is found that, in the energy region from above Fermi energy to 150MeV/u, nuclear stopping is very sensitive to the isospin dependence of in-medium nucleon-nucleon cross section, but insensitive to symmetry potential. From this investigation, we propose that nuclear stopping can be used as a new probe to extract the information on the isospin dependence of in-medium nucleon-nucleon cross section in intermediate energy heavy ion collisions

Isospin Effect on the Process of Multifragmentation and Dissipation at Intermediate Energy Heavy Ion Collisions

In the simulation of intermediate energy heavy ion collisions by using the isospin dependent quantum molecular dynamics, the isospin effect on the process of multifragmentation and dissipation has been studied. It is found that the multiplicity of intermediate mass fragments $N_{imf}$ for the neutron-poor colliding system is always larger than that for the neutron-rich system, while the quadrupole of single particle momentum distribution $Q_{zz}$ for the neutron-poor colliding system is smaller than that of the neutron-rich system for all projectile-target combinations studied at the beam energies from about 50MeV/nucleon to 150MeV/nucleon. Since $Q_{zz}$ depends strongly on isospin dependence of in-medium nucleon-nucleon cross section and weakly on symmetry potential at the above beam energies, it may serve as a good probe to extract the information on the in-medium nucleon-nucleon cross section. The correlation between the multiplicity $N_{imf}$ of intermediate mass fragments and the total numer of charged particles $N_c$ has the behavior similar to $Q_{zz}$, which can be used as a complementary probe to the in-medium nucleon-nucleon cross section.Comment: 18 pages, 9 figure

Universal construction of order parameters for translation-invariant quantum lattice systems with symmetry-breaking order

For any translation-invariant quantum lattice system with a symmetry group G, we propose a practical and universal construction of order parameters which identify quantum phase transitions with symmetry-breaking order. They are defined in terms of the fidelity between a ground state and its symmetry-transformed counterpart, and are computed through tensor network representations of the ground-state wave function. To illustrate our scheme, we consider three quantum systems on an infinite lattice in one spatial dimension, namely, the quantum Ising model in a transverse magnetic field, the quantum spin-1/2 XYX model in an external magnetic field, and the quantum spin-1 XXZ model with single-ion anisotropy. All these models have symmetry group Z(2) and exhibit broken-symmetry phases. We also discuss the role of the order parameters in identifying factorized states