[en] We report on the tunneling density of states (DOS) in strongly disordered ultrathin Be films quench condensed at 20K. Above 5K, the DOS shows the well-known logarithmic anomaly at the Fermi level. Only in a narrow temperature range near 2K is the DOS linearly dependent on energy, as predicted by Efros and Shklovskii. However, both the zero-bias conductance and the slope of the linear DOS are found to decrease drastically with decreasing temperature. Tunneling measurements at mK temperatures have revealed conclusively that a hard correlation gap opens up in the DOS

[en] Adsorption of aromatic compounds, including polycyclic aromatic hydrocarbons, nitrobenzenes, phenols, and anilines, on a bamboo biochar produced at 700 °C (Ba700) was investigated with the mechanism discussion by isotherm fitting using the Polanyi-theory based Dubinin–Ashtakhov (DA) model. Correlations of adsorption capacity (Q"0) of organic compounds with their molecular sizes and melting points, as well as correlations of adsorption affinity (E) with their solvatochromic parameters (i.e., π* and α_m), on the biochar, were developed and indicating that adsorption is captured by the pore filling mechanism and derived from the hydrophobic effects of organic compounds and the forming of π-π electron donor-acceptor (EDA) interactions and hydrogen bonding interactions of organic molecules with surface sites of the biochar. The effects of organic molecular sizes and melting points on adsorption capacity are ascribed to the molecular sieving effect and the packing efficiency of the organic molecules in the biochar pores, respectively. These correlations can be used to quantitatively estimate the adsorption of organic compounds on biochars from their commonly physicochemical properties including solvatochromic parameters, melting points and molecular cross-sectional area. The prediction using these correlations is important for assessing the unknown adsorption behaviors of new organic compounds and also helpful to guide the surface modification of biochars and make targeted selection in the environmental applications of biochars as adsorbents. - Highlights: • Adsorption of organic chemicals on biochars are captured by pore filling mechanism. • Adsorption is derived from Van der Waals force, π-π EDA and H-bonding interactions. • Adsorption capacity is negatively correlated with organic molecular sizes/melting points. • Adsorption capacity is restricted by molecular sieving effect and packing efficiency. • Adsorption affinity has a LSER with chemical solvatochromic parameters. - Correlations of sorption capacity and affinity with properties of aromatic compounds on a bamboo biochar were developed for sorption mechanism exploring and sorption behavior predicting.

[en] Crown peptide is a kind of special conformation, in the structure of which there is regular array about the main chain containing imido groups, and presents coronary analogy to crown ether. There is high symmetrical ionophore which belong to C_n point group. The channels or apertures can form more easily in order to recognize certain ion or molecular, and also the function of intending dual-recognition and the ability for transporting as ionophores can be achieved. (authors)

[en] Based on the theory of seepage and diffusion migration of radon in porous media, the mathematical model of radon migration in tubular porous media was established, and the analytical solution of radon concentration distribution and the calculation formula of radon exhalation rate under steady state were obtained. Through the study, the following conclusions are obtained: 1) The radon concentration and radon concentration gradient near the inner and outer surface of the tube wall decrease with the increase of diffusion coefficient. 2) The radon exhalation rate on the inner and outer surface of the tube increases with the increase of diffusion coefficient, and gradually tends to the maximum value; The radon exhalation share of the whole tube increases with the increase of diffusion coefficient and tends to one. 3) The peak value of radon concentration in the tube wall decreases with the increase of the pressure difference between the inner and outer surfaces of the tube; The maximum radon concentration peak at pressure difference was 20 Pa; The minimum radon concentration peak at pressure difference was 60 Pa. 4) When there is a pressure difference between the inner and outer surfaces of the circular tube, the radon exhalation rate of the surface of the circular tube on the high-pressure side decreases with the increase of the pressure gradient, and gradually tends to zero; the radon exhalation rate of the surface of the circular tube at the low-pressure side is increased with the increase of the pressure gradient, and the maximum value is gradually increased; The radon exhalation share of the whole circular tube increases with the increase of the pressure difference, and gradually tends to one. (authors)

[en] We have studied the vortex pinning via their magnetic interaction with a periodic structure of parallel magnetic stripes. Superconducting Pb₈₂Bi₁₈ alloy films were covered by an insulating Ge layer and a periodic Ni array of magnetic stripes was fabricated on the top of the Ge layer by electron-beam lithography and thermal evaporation. The critical current density was significantly stronger when the current was applied parallel to the stripes than when the current was perpendicular to the stripes. This is attributed to the barrier to the vortex motion provided by the magnetic interaction with the magnetic stripes. The enhancement in critical current was most significant at temperatures close to the superconducting transition temperature.

[en] The superconducting properties of Pb₈₂Bi₁₈ alloy films deposited on ferromagnetic nanowire arrays have been investigated. Ferromagnetic Co or Ni nanowires are first electroplated into the columnar pores of anodic aluminum oxide (AAO) membranes. Superconducting Pb₈₂Bi₁₈ films are then quench condensed onto the polished surface of the AAO membranes filled with magnetic nanowires. A strong dependence of the Pb₈₂Bi₁₈ superconducting properties on the ratio of the superconducting film thickness to the magnetic nanowire diameter and material variety was observed.

[en] Highlights: • Sorption of 22 organic compounds by PyHAs treated at 300–700 °C was investigated. • PyHAs were changed from aliphatic and nonporous to aromatic and porous by pyrolysis. • Sorption was dominated by nonlinear partition for low temperature-treated PyHAs. • Sorption was dominated by pore-filling adsorption for high temperature-treated PyHAs. • Sorption capacity and affinity varied with the pyrolytic temperature of PyHAs. Humic acids (HAs) are frequently subjected to pyrolysis and carbonization by wildfires, which could significantly change the sorption of organic contaminants and their environmental risks in natural system. In previous studies, sorption of organic compounds was investigated for HAs pyrolyzed at temperature below 330 °C, but not for HAs pyrolyzed at higher temperature. Therefore, in this study, sorption of 22 typical organic compounds by HAs pyrolyzed at a series of temperatures from 300 to 700 °C was investigated. Sorption of organic compounds was dominated by nonlinear partition for HAs pyrolyzed at low temperature (e.g., 300 and 400 °C) due to the aliphatic and nonporous structures of pyrolyzed humic acids (PyHAs), while it was dominated by pore-filling adsorption for HAs pyrolyzed at high temperature (e.g., 700 °C) due to the aromatic and porous structures of PyHAs. For HAs pyrolyzed at moderate temperature (e.g., 450, 500 and 600 °C), both nonlinear partition and pore-filling adsorption were responsible for the sorption of organic compounds. Meanwhile, the contribution of pore-filling adsorption to overall sorption increased but the contribution of nonlinear partition decreased with the increasing pyrolytic temperature of PyHAs, attributed to the structure change of PyHAs from aliphatic and nonporous to the aromatic and porous. Moreover, with the increasing pyrolytic temperature of PyHAs, sorption affinity of organic compounds increased, while the change of sorption capacity could be explained by the decrease of nonlinear partition and the increase of pore-filling adsorption. The obtained results could help to evaluate the transport, bioavailability and health risks of organic contaminants in the environment.

[en] In order to meet the requirement of automatic radioactive contamination detection, a system is developed, the software of the detection system is designed. Cooperated with radioactive contamination test hardware system, a set of software system is developed based on the Python, through the PLC control of stepping motor and connected via STM32 detector. The system is designed to measure the radioactivity of the filter framework of the ventilation system at nuclear facilities with high precision, to avoid the artificial measurement caused by the radioactive pollution and other issues, to improve the measurement accuracy and measuring efficiency. (authors)

[en] A Cu–2.5%Sn alloy was fabricated by continuous unidirectional solidification (CUS). The EBSD was used to analyse the microstructure of CSU Cu–2.5%Sn alloy. The results show that the alloy is composed of coarse columnar grains, which grow along the direction of [001] and [101], and the average diameter of the columnar grains is about 470 μm. Most of grain boundaries between the columnar grains are small-angle and the rest are high-angle grain boundaries. It is also found that the CUS Cu–2.5%Sn alloy has strong {110} <110> texture and cubic texture. (paper)

[en] We report measurements of the superconducting to normal transition of ultra-thin granular Al films in parallel magnetic fields, H _parallel . The parallel critical field, H_cparallel , in our samples is Pauli spin-paramagnetically limited. We find that the critical field transition goes from second-order to strongly first-order at a tricritical point, T_tr, near 250 mK. The first- order transition is characterized by a giant hysteresis in the critical field, ΔH_cparallel similar 2.5 kG. In the hysteretic region we find that the films are far out of thermodynamic equilibrium and exhibit very slow, τ similar 10⁴ s, glass-like, stretched-exponential relaxation. In addition, we observe significant avalanches. These observations are discussed in terms of a random array of Josephson junctions. (orig.)