Gap solitons of a super-Tonks-Girardeau gas in a one-dimensional periodic potential

We study the stability of gap solitons of the super-Tonks-Girardeau bosonic gas in one-dimensional periodic potential. The linear stability analysis indicates that increasing the amplitude of periodic potential or decreasing the nonlinear interactions, the unstable gap solitons can become stable. In particular, the theoretical analysis and numerical calculations show that, comparing to the lower-family of gap solitons, the higher-family of gap solitons are easy to form near the bottoms of the linear Bloch band gaps. The numerical results also verify that the composition relations between various gap solitons and nonlinear Bloch waves are general and can exist in the super-Tonks-Girardeau phase.Comment: 7 pages,6 figure

Reduced dynamics with renormalization in solid-state charge qubit measurement

Quantum measurement will inevitably cause backaction on the measured system, resulting in the well known dephasing and relaxation. In this report, in the context of solid--state qubit measurement by a mesoscopic detector, we show that an alternative backaction known as renormalization is important under some circumstances. This effect is largely overlooked in the theory of quantum measurement.Comment: 12 pages, 4 figure

Electrical conductivity of anhydrous and hydrous gabbroic melt under high temperature and high pressure: implications for the high-conductivity anomalies in the mid-ocean ridge region

The electrical conductivity of gabbroic melt with four different water contents (i.e., 0 %, 2.59 wt %, 5.92 wt %, and 8.32 wt %) was measured at temperatures of 873–1373 K and pressures of 1.0–3.0 GPa using a YJ-3000t multi-anvil high-pressure apparatus and Solartron-1260 impedance spectroscopy analyzer. At a fixed water content of 2.59 wt %, the electrical conductivity of the sample slightly decreased with increasing pressure in the temperature range of 873–1373 K, and its corresponding activation energy and activation volume were determined as 0.87 ± 0.04 eV and −1.98 ± 0.02 cm3 molec.−1, respectively. Under the certain conditions of 873–1373 K and 1.0 GPa, the electrical conductivity of the gabbroic melts tends to gradually increase with a rise in water content from 0 wt % to 8.32 wt %, and the activation enthalpy decreases from 0.93 to 0.63 eV accordingly. Furthermore, functional relation models for the electrical conductivity of gabbroic melts with variations of temperature, pressure, and water content were constructed at high-temperature and high-pressure conditions. In addition, the dependence relation of the electrical conductivity of melts with the degree of depolymerization was explored under conditions of four different water contents at 1373 K and 1.0 GPa, and three previously available reported results on those of representative calc-alkaline igneous rock melts (i.e., dacitic melt, basaltic melt, and andesitic melt) were compared in detail. In combination with our presently acquired electrical conductivity data on gabbroic melt with four different water contents and the available data on polycrystalline olivine, the electrical conductivity of a gabbroic melt–olivine system with variation of the volume percentage of anhydrous and hydrous melts was successfully constructed by using the typical Hashin–Shtrikman upper-bound model. In light of the electrical conductivity of the gabbroic melt–olivine system with previous magnetotelluric (MT) results, we find that anhydrous and hydrous gabbroic melts can be employed to reasonably interpret the high-conductivity anomalies in the Mohns Ridge of the Arctic Ocean.</p

Temporal variability in trace metal solubility in a paddy soil not reflected in uptake by rice (Oryza sativa L.)

Alternating flooding and drainage conditions have a strong influence on redox chemistry and the solubility of trace metals in paddy soils. However, current knowledge of how the effects of water management on trace metal solubility are linked to trace metal uptake by rice plants over time is still limited. Here, a field-contaminated paddy soil was subjected to two flooding and drainage cycles in a pot experiment with two rice plant cultivars, exhibiting either high or low Cd accumulation characteristics. Flooding led to a strong vertical gradient in the redox potential (Eh). The pH and Mn, Fe, and dissolved organic carbon concentrations increased with decreasing Eh and vice versa. During flooding, trace metal solubility decreased markedly, probably due to sulfide mineral precipitation. Despite its low solubility, the Cd content in rice grains exceeded the food quality standards for both cultivars. Trace metal contents in different rice plant tissues (roots, stem, and leaves) increased at a constant rate during the first flooding and drainage cycle but decreased after reaching a maximum during the second cycle. As such, the high temporal variability in trace metal solubility was not reflected in trace metal uptake by rice plants over time. This might be due to the presence of aerobic conditions and a consequent higher trace metal solubility near the root surface, even during flooding. Trace metal solubility in the rhizosphere should be considered when linking water management to trace metal uptake by rice over time

ELUCID V. Lighting dark matter halos with galaxies

In a recent study, using the distribution of galaxies in the north galactic pole of SDSS DR7 region enclosed in a 500\mpch box, we carried out our ELUCID simulation (Wang et al. 2016, ELUCID III). Here we {\it light} the dark matter halos and subhalos in the reconstructed region in the simulation with galaxies in the SDSS observations using a novel {\it neighborhood} abundance matching method. Before we make use of thus established galaxy-subhalo connections in the ELUCID simulation to evaluate galaxy formation models, we set out to explore the reliability of such a link. For this purpose, we focus on the following a few aspects of galaxies: (1) the central-subhalo luminosity and mass relations; (2) the satellite fraction of galaxies; (3) the conditional luminosity function (CLF) and conditional stellar mass function (CSMF) of galaxies; and (4) the cross correlation functions between galaxies and the dark matter particles, most of which are measured separately for all, red and blue galaxy populations. We find that our neighborhood abundance matching method accurately reproduces the central-subhalo relations, satellite fraction, the CLFs and CSMFs and the biases of galaxies. These features ensure that thus established galaxy-subhalo connections will be very useful in constraining galaxy formation processes. And we provide some suggestions on the three levels of using the galaxy-subhalo pairs for galaxy formation constraints. The galaxy-subhalo links and the subhalo merger trees in the SDSS DR7 region extracted from our ELUCID simulation are available upon request.Comment: 18 pages, 13 figures, ApJ accepte

Impacts of soil and water pollution on food safety and health risks in China

Environmental pollution and food safety are two of the most important issues of our time. Soil and water pollution, in particular, have historically impacted on food safety which represents an important threat to human health. Nowhere has that situation been more complex and challenging than in China, where a combination of pollution and an increasing food safety risk have affected a large part of the population. Water scarcity, pesticide over-application, and chemical pollutants are considered to be the most important factors impacting on food safety in China. Inadequate quantity and quality of surface water resources in China have led to the long-term use of waste-water irrigation to fulfill the water requirements for agricultural production. In some regions this has caused serious agricultural land and food pollution, especially for heavy metals. It is important, therefore, that issues threatening food safety such as combined pesticide residues and heavy metal pollution are addressed to reduce risks to human health. The increasing negative effects on food safety from water and soil pollution have put more people at risk of carcinogenic diseases, potentially contributing to ‘cancer villages’ which appear to correlate strongly with the main food producing areas. Currently in China, food safety policies are not integrated with soil and water pollution management policies. Here, a comprehensive map of both soil and water pollution threats to food safety in China is presented and integrated policies addressing soil and water pollution for achieving food safety are suggested to provide a holistic approach