[en] Lead free double perovskites La₂NiMnO₆ were first studied for potential application on solar cells. The rhombohedral and the monoclinic La₂NiMnO₆, with B-site of Ni³⁺/Mn³⁺, were respectively formed under different synthesizing conditions. The experimental results show that the monoclinic La₂NiMnO₆ sample has a band gap of 1.4 eV and valence band of −5.8 eV, on the other hand, the respective values for rhombohedral sample are 1.2 eV and −5.7 eV. The density function theory calculation demonstrates that the calculated band gap for the monoclinic La₂NiMnO₆ is larger than that for the rhombohedral one. However, the electronic structures for these La₂NiMnO₆ are found very similar to each other. Our combined experimental and theoretical studies indicate that, from the aspects of band gaps and energy levels, double perovskite La₂NiMnO₆ of monoclinic phase could be a better candidate than that of rhombohedral phase for light harvesting. - Highlights: • Lead-free La₂NiMnO₆ are first studied for application on perovskite solar cell. • Electronic structures of monoclinic and rhombohedral La₂NiMnO₆ is very similar. • Monoclinic La₂NiMnO₆ is a better candidate than rhombohedral one for solar cell.

[en] Triple-negative breast cancer (TNBC) is characterized by distinct biological and clinical pathological features. Due to its high aggressive and malignant, and lack of effective therapeutic targets, it has a worse prognosis. Compared with Non-TNBC, TNBC shows some characteristics in magnetic resonance imaging. Functional MR imaging, such as perfusion weighted imaging, diffusion-weighted imaging, and magnetic resonance spectroscopy, can quantitatively evaluate the tumor microvascular perfusion and cellular metabolism, and can also monitor neoadjuvant chemotherapy effect on TNBC. Here, we summarized the MRI application status on identifying of TNBC and assessing of neoadjuvant chemotherapy efficacy. (authors)

[en] The incidence of human papillomavirus (HPV)-positive oropharyngeal cancer is growing year by year. Compared with the other head and neck squamous cell carcinoma, HPV-positive oropharyngeal cancer has unique biological characteristics and better prognosis. According to the 8^th edition TNM staging of UICC/AJCC, HPV-positive and HPV-negative oropharyngeal cancer have been classified separately. In 2018, College of American Pathologists and American Society of Clinical Oncology released the guidelines on the HPV testing in head and neck cancer. Several published clinical trials have demonstrated that de-intensified chemoradiation might be efficacious treatment of HPV-positive oropharyngeal cancer. (authors)

[en] Highlights: • Examine the IBP structure of residential natural gas from the perspective of demand analysis. • A new EIR-ELES model is proposed to estimate natural gas price affordability. • Consider the effect of electricity substitute on household natural gas consumption. • Natural gas price affordability, price elasticity of demand, and basic volume of demand for residential users are estimated. In order to promote reasonable resource utilization and improve social equity, all cities with gas supply in China has implemented increasing block pricing (IBP) policy for residential natural gas from Jan. 2016. This paper examines the IBP structure of residential natural gas from the perspective of demand analysis. Based on Expenditure-Income Ratio (EIR) method and Extended Linear Expenditure System (ELES), a new EIR-ELES model is proposed to estimate natural gas price affordability of different kinds of residential users by considering the effect of electricity substitute on household natural gas consumption. Taking Beijing as an example, an empirical research is carried out in this paper. The results show that average price elasticity of residential natural gas demand is −0.4621 in 2016, inelastic; residential natural gas average price affordability is between 4.17 and 7.48 CNY/m3 in 2016, which is much higher than the prices in three blocks, but basic volume of demand for residential users with different income levels are much lower than the volume in the first block. Based on these results, future directions and actions for the design and improvement of residential natural gas IBP system are suggested.

[en] The degradation characteristics of clopyralid irradiated by electron beam (EB) was studied in aqueous solutions. The effects of factors, such as initial clopyralid concentrations, addition of radicals scavenger, initial solution pH and addition of H₂O₂, were investigated on clopyralid degradation efficiency and mechanism. It was found that the EB-radiolysis was an effective way to degrade clopyralid and its degradation rate decreased with the increasing of substrate concentration. In the investigated initial concentrations range of 100-400 mg L^-1, the radiolytic degradation of clopyralid followed a pseudo-first kinetic order. The results from addition of radicals scavenger indicated that both ^·OH and e_aq^- played significant roles in the degradation of clopyralid. Furthermore, the alkaline condition and addition of H₂O₂ (<10 mM) in the solution also slightly enhanced the efficiency of clopyralid degradation. The ion chromatography analysis showed that some organic acids (formic acid, acetic acid and oxalic acid) were formed, while the completely dechlorination of the substrate was achieved and organic nitrogen was recovered in the form of ammonium and nitrate ions during the irradiation process. (author)

[en] To make clear the genetic variation for cold tolerance and to dig associated elite alleles in cut chrysanthemum, the present study was set out to assess the cold tolerance in terms of semi-lethal temperature (LT₅₀) in a panel of 83 cultivars at seedling stage using the relative electric conductivity and logistic equation. The favorable alleles responsible for cold tolerance were analyzed via association analysis. The results showed that LT₅₀ varied between -10.99 ∼ 1.86℃ with a variation coefficient of 79.81%, which indicated a high level of genetic variation for the cold tolerance in the investigated cut chrysanthemums. LT₅₀ -based cluster analysis grouped the 83 cut chrysanthemums into 4 types, including tolerant (21.67%), moderate tolerant (22.89%), low tolerant (32.53%) and cold-sensitive cultivars (22.89%). The mix linear model-based association analysis identified 11 SSR markers that were significantly associated with LT₅₀ (P < 0.01), with phenotypic effect in a range of -3.51 ∼ 0.83 and individually explained phenotypic variation varying in 11.54% ∼ 18.83%. In the 11 significant alleles, 8 favorable alleles were helpful to enhance cold tolerance, particularly the E7M12-13 showed a significant level of phenotypic effect on LT₅₀ at P < 0.01, and 6 cold-tolerant cultivars, i.e., Nannong Jinningmeng, Qx097, QD028, Qx049, Qx153, and Qx008 that carry the favorable allele were finally screened out for future use. The findings of the present study add new understanding to the genetic variation of cold tolerance in cut chrysanthemum and will provide guidelines for genetic improvement and molecular marker assisted selection breeding for the target trait in future. (authors)

[en] To study the variation and levels of atmospheric radon concentration in Qingdao area, continuous measurements were performed hourly over a three-year period from September 2006 to August 2009. With 16817 measured data, levels and variations were analyzed, and the trend in diurnal and annual variations was studied. The average concentration of atmospheric radon in Qingdao area is (5.0±3.0) Bq/m³. The average diurnal pattern of radon concentration showed that diurnal maximum appears in the early morning, and the minimum appears in late afternoon. The annual pattern features a maximum in December and a minimum in June, which is closely related to the maritime monsoon climate in Qingdao. (authors)

[en] The mechanical spectra of Pr_1-xSr_xFeO_3-δ (x = 0.5, 0.55, and 0.6) ceramics were performed at kHz frequencies from 100 to 350 K. An internal friction (IF) peak associated with modulus defect around 130 K and a modulus kink at 200 K were observed. This IF peak temperature shows frequency-dispersive behavior. The dielectric spectra and magnetization measurements were used to clarify the origin of the anomaly in IF and modulus. The dielectric spectra provide clear evidence for the relaxation behavior of IF peak and the activation energies of 0.14, 0.13, and 0.11 eV were derived from the Arrhenius law for Pr_0.5Sr_0.5FeO₃, Pr_0.45Sr_0.55FeO₃, and Pr_0.4Sr_0.6FeO₃ samples, respectively. The relaxation behavior is ascribed to the charge-carrier hopping between Fe³⁺ and Fe⁴⁺. Furthermore, the magnetization measurement confirms that the kink in the reduced Young's modulus is associated with a spin-glass transition. In addition, another dielectric anomaly at 200 K may be related to the magneto dielectric effect. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

[en] MoS₂ atomic layers with a lateral grain size of 50–100 μm were synthesized by a new two-step chemical vapor deposition method. The product was confirmed to be bilayer MoS₂ by the characterization of Raman spectroscopy, atomic force microscopy and high-resolution transmission electron microscopy. The growth mechanism and the influencing factors during the growth process of the bilayer MoS₂ were proposed and the so-obtained large lateral grain sizes of MoS₂ atomic layers were attributed to the high surface mobility and enhanced surface evaporation. The resistive gas sensors based on as-prepared bilayer MoS₂ films showed a p-type character and achieved a superior sensitivity of 2.6% to 1 ppm NO₂ gas at room temperature. - Highlights: • A new two-step chemical vapor deposition method was used to synthesize MoS₂. • Bilayer MoS₂ with lateral grain sizes of 50–100 μm were obtained. • The sensitivity of the gas sensors is 2.6% to 1 ppm NO₂ gas at room temperature.

[en] Highlights: • A comprehensive control of pore size and wall thickness in piezoceramic honeycombs. • The effects of pore size and wall thickness on piezoelectric properties also have been studied. • The process parameters for microstructure adjusting during freeze-casting can be applied to other ceramics. 3-1 type porous lead zirconate titanate (PZT) ceramics with unidirectionally aligned pore channels were prepared by freeze-casting process of which the freezing temperature was varied at − 10 ~ − 100 °C, and the solid content of slurries was changed at 15 ~ 40 vol%. Characterization of pore size distributions and wall thickness distributions demonstrated the freezing temperature significantly influenced the pore size and wall thickness, while the solid content had strong influence on the porosity. When the solid content was stationary, the pore size decreased with decreasing freezing temperature and the wall thickness also tended to decrease. When the freezing temperature was constant, the porosity decreased as the initial solid content increased, meaning decreased ratio of pore size and wall thickness. The fabricated samples exhibited high piezoelectric coefficient and there was a trend that it increased with the simultaneous decrease of pore size and wall thickness.