The Equation of State and Quark Number Susceptibility in Hard-Dense-Loop Approximation

Based on the method proposed in [ H. S. Zong, W. M. Sun, Phys. Rev. \textbf{D 78}, 054001 (2008)], we calculate the equation of state (EOS) of QCD at zero temperature and finite quark chemical potential under the hard-dense-loop (HDL) approximation. A comparison between the EOS under HDL approximation and the cold, perturbative EOS of QCD proposed by Fraga, Pisarski and Schaffner-Bielich is made. It is found that the pressure under HDL approximation is generally smaller than the perturbative result. In addition, we also calculate the quark number susceptibility (QNS) at finite temperature and finite chemical potential under hard-thermal/dense-loop (HTL/HDL) approximation and compare our results with the corresponding ones in the previous literature.Comment: 12 pages, 3 figure

Thermoelectric three-terminal hopping transport through one-dimensional nanosystems

A two-site nanostructure (e.g, a "molecule") bridging two conducting leads and connected to a phonon bath is considered. The two relevant levels closest to the Fermi energy are connected each to its lead. The leads have slightly different temperatures and chemical potentials and the nanos- tructure is also coupled to a thermal (third) phonon bath. The 3 x 3 linear transport ("Onsager") matrix is evaluated, along with the ensuing new figure of merit, and found to be very favorable for thermoelectric energy conversion.Comment: Accepted by Phys. Rev.

Emergence of triplet orbital pairing and non-Abelian states in ultracold multi-orbital optical lattices with quadratic band touching

It is found that all the {\em singlet orbital pairing} instabilities are {\em absent} in a class of spin-polarized multi-orbital systems with quadratic band touching, which opens the way for {\em triplet orbital pairing} order. The ground states are found to be {\em non-Abelian} states with p-wave orbital pairing in checkerboard (away from 1/2 filling) and kagome (above 1/3 filling) lattices with {\em isotropic} attractive interaction which can be realized in ultracold multi-orbital optical lattices. The special property of such systems is generalized to more classes of multi-orbital systems, where the fully-gapped {\em non-Abelian} states are possibly the ground states. Those findings are helpful in achieving topological quantum computation.Comment: Submitted to Phys. Rev. Let

How are typical urban sewage treatment technologies going in China: from the perspective of life cycle environmental and economic coupled assessment

Sewage treatment is an important public service, but it consumes a lot of energy and chemicals in the process of removing wastewater pollutants, which may cause the risk of pollution transfer. To find the corresponding hot issues, this paper took the lead in integrating life cycle assessment (LCA) with life cycle costing (LCC) to evaluate four most typical sewage treatment technologies with more than 85% share in China. It is found that anaerobic/anoxic/oxic (AAO) was the optimal treatment scheme with relatively small potential environmental impact and economic load. The normalized results show that the trends of the four technologies on eleven environmental impact categories were basically the same. Marine aquatic ecotoxicity potential accounted for more than 70% of the overall environmental impact. Contribution analysis indicates that electricity and flocculant consumption were the main processes responsible for the environmental and economic burden. Overall, electricity consumption was the biggest hot spot. Sensitivity analysis verifies that a 10% reduction in electricity could bring high benefits to both the economy and the environment. These findings are expected to provide effective feedback on the operation and improvement of sewage treatment

Efficiency assessment of rural domestic sewage treatment facilities by a slacked-based DEA model

In the context of sustainable development, a number of rural domestic sewage treatment facilities had been built in China to solve the problem of rural domestic sewage pollution. The comprehensive, quantitative and objective efficiency assessment of facilities is urgent. This study used a non-radial slacked-based data envelopment analysis model combined with cluster analysis to construct an index system covering multiple aspects, including three inputs and four outputs to assess 681 facilities. These samples selected from the biggest demonstration area are the most representative for and exceed 2/5 of the running facilities all over the country. The average efficiency score of samples was 0.496 meaning the improvement potential was about 50.4%. Only 27 samples were relatively effective, scoring 1. The remaining 654 facilities had different levels of input excesses or output shortfalls, which should be the key objects to improve overall performance. In addition, there was evidence that output indicators had more room for improvement than input indicators. The analysis of sensitivity on inputs and outputs confirmed that the idleness and poor treatment effects of rural sewage treatment facilities should be concerned. Finally, Kruskal–Wallis non-parametric test verified that technology and load rate of facilities have significant impacts on efficiency. The performance evaluation results could not only provide guidance for the local government to strengthen the supervision and operation of facilities, but also potentially provide reference for the construction, operation and management of rural sewage treatment facilities in China

Local Ferroelectricity in SrTiO_3 Thin Films

The temperature-dependent polarization of SrTiO_3 thin films is investigated using confocal scanning optical microscopy. A homogeneous out-of-plane and inhomogeneous in-plane ferroelectric phase are identified from images of the linear electrooptic response. Both hysteretic and non-hysteretic behavior are observed under a dc bias field. Unlike classical transitions in bulk ferroelectrics, local ferroelectricity is observed at temperatures far above the dielectric permittivity maximum. The results demonstrate the utility of local probe experiments in understanding inhomogeneous ferroelectrics.Comment: 8 pages, 3 figures, accepted for publication in PR

Excited-state dynamics of [Ru(S–Sbpy)(bpy)2]2+to form long-lived localized triplet states

The novel photosensitizer [Ru( S−S bpy)(bpy) 2 ] 2+ harbors two distinct sets of excited states in the UV/Vis region of the absorption spectrum located on either bpy or S−S bpy ligands. Here, we address the question of whether following excitation into these two types of states could lead to the formation of different long-lived excited states from where energy transfer to a reactive species could occur. Femtosecond transient absorption spectros- copy identifies the formation of the final state within 80 fs for both excitation wavelengths. The recorded spectra hint at very similar dynamics following excitation toward either the parent or sulfur- decorated bpy ligands, indicating ultrafast interconversion into a unique excited-state species regardless of the initial state. Non-adiabatic surface hopping dynamics simulations show that ultrafast spin−orbit-mediated mixing of the states within less than 50 fs strongly increases the localization of the excited electron at the S−S bpy ligand. Extensive structural relaxation within this sulfurated ligand is possible, via S−S bond cleavage that results in triplet state energies that are lower than those in the analogue [Ru(bpy)3 ]2+ . This structural relaxation upon localization of the charge on S−S bpy is found to be the reason for the formation of a single long-lived species independent of the excitation wavelength

Sustainability efficiency assessment of wastewater treatment plants in China: A data envelopment analysis based on cluster benchmarking

Quantitative evaluation on the efficiency of wastewater treatment plants (WWTPs) is a key issue that needs to be solved. For this purpose, data envelopment analysis (DEA) was employed to establish a comprehensive efficiency evaluation system on WWTPs, including three inputs of operating cost, electricity consumption and labor, three desirable outputs of chemical oxygen demand (COD) removal rate, ammonia nitrogen (NH3–N) removal rate and reclaimed water yield, and one undesirable output of dry sludge yield. 861 WWTPs in China were assessed by a slacked-based DEA model based on cluster benchmarking. The technology gap ratio (TGR) confirmed that large WWTPs operated more efficiently than small ones. The WWTPs had an average efficiency score of 0.611. Among them, 170 samples were relatively efficient with a score of 1, which means these samples could be a benchmark for other inefficient samples. Different degrees of input excesses or output shortfalls existed in 691 inefficient samples and these samples should be the key objects to improve the operational efficiency. Furthermore, through the Kruskal-Wallis test, the influent COD concentration and capacity load rate showed significant effects on the WWTP performance. These findings, derived from a simple but effective framework, have potential value for managers to make decisions

Non-Abelian toplogical superconductors from topological semimetals and related systems under superconducting proximity effect

Non-Abelian toplogical superconductors are characterized by the existence of {zero-energy} Majorana fermions bound in the quantized vortices. This is a consequence of the nontrivial bulk topology characterized by an {\em odd} Chern number. It is found that in topological semimetals with a single two-bands crossing point all the gapped superconductors are non-Abelian ones. Such a property is generalized to related but more generic systems which will be useful in the search of non-Abelian superconductors and Majorana fermions