[en] Highlights: • Temporary aeration shortened the initial acid inhibition phase for methanogens. • COD decreased faster in the hybrid bioreactor than that in the anaerobic control. • Methane generations from hybrid bioreactors were 133.4 L/kg_v_s and 113.2 L/kg_v_s. • MSW settlement increased with increasing the frequency of intermittent aeration. - Abstract: Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10 months. The hybrid bioreactors were operated in an aerobic–anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia–nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75 d and 60 d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4 L/kg_v_s and 113.2 L/kg_v_s. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens

[en] Red emission with high color purity in Y₂Ti₂O₇:Yb³⁺,Er³⁺ material is successfully obtained by high-concentration doping of Yb³⁺ and Er³⁺ under 980 and 1550 nm excitation based on the special layer structure of pyrochlore crystal. It shows that Yb³⁺ ion content and excitation wavelength greatly influence the red emission percent of total up-conversion luminescence intensity of Y₂Ti₂O₇:Yb³⁺,Er³⁺. Y₂Ti₂O₇:Yb³⁺,Er³⁺ shows much better red color purity at 1550 nm excitation than at 980 nm. Furthermore, the co-doping of Yb³⁺ ions considerably boosts the red emission under 980 or 1550 nm pumping with different luminescence mechanisms compared with Y₂Ti₂O₇:Er³⁺ sample. The red emission percent of total up-conversion luminescence intensity gradually increases with the increment of Yb³⁺ concentration at both excitation sources. The red-to-green emission ratio of the sample is 6.97 (980 nm) and 23.26 (1550 nm) when the Yb³⁺ content is 30 mol%.

[en] The process for preparing Y-Ba-Cu-O system high T_c superconducting film using nitrates CVD pyrolysis method is introduced. The thickness of film is about 25 ∼ 70 μm, and its critical temperature is 79.37 K

[en] A Tm³⁺-doped silica-germanate was successfully prepared by high-temperature melting method in this work and compared with traditional silicate and germanate glasses comprehensively. The DSC results indicated a better ability against thermal damage (higher T_g=636 °C) compared with silicate glass together with better thermal stability (ΔT=106 °C and S=3.17) than germanate (ΔT=99 °C and S=2.64) glass. Intense 1.8 μm emission in the silica-germanate glass was also obtained when pumping by an 808 nm laser diode, which possessed larger peak absorption and emission cross section (3.15×10^–21 cm² and 7.08 ×10^–21 cm²). Finally, the structure analysis suggested a low phonon energy and high rare earth ions solubility in silica-germanate glass through Raman spectra and X-ray photoelectron spectroscopy. All results indicate that the prepared silica-germanate glass is a promising candidate for 2 μm laser applications.

[en] In this paper, Er³⁺ doped Y₂O₃ and Nb₂O₅ modified germanate glasses possessing good thermal stability are reported. On the basis of absorption spectra and Judd–Ofelt theory, a detailed investigation of Judd–Ofelt intensity parameters (Ω_2,4,6) and radiative properties is carried out. Moreover, emission cross section at 2.7 μm is calculated based on Füchtbauer–Ladenburg equation and compared with other Er³⁺ doped glass systems. A reasonable energy transfer mechanism is proposed. It is interesting that the emission cross section and radiative transition probability in 5 mol% Nb₂O₅ modified germanate glass are much larger than those with 5 mol% Y₂O₃. Results indicate that present germanate glasses along with excellent 2.7 μm spectroscopic performance might have potential application for mid-infrared fiber laser. Highlights: • Er³⁺ doped Y₂O₃ and Nb₂O₅ modified germanate glasses were prepared. • The investigated samples possess superior thermal property. • Judd–Ofelt parameters and radiative properties are calculated and analyzed. • Large emission cross section and high radiative probability at 2.7 μm are achieved. • A reasonable energy transfer mechanism is proposed

[en] Er³⁺ doped Y₂O₃ and Nb₂O₅ modified germanate glasses have been reported which possesses excellent thermal stability. Near infrared emission characteristics upon excitation of a conventional 980 nm laser diode have been investigated. According to absorption spectra and refractive index, Judd–Ofelt intensity parameters, spontaneous radiative transition probabilities, radiative lifetimes and stimulated emission cross sections have been calculated and discussed. These results indicate that the predicted spontaneous transition probability and emission cross section of Er³⁺:⁴I_13/2→⁴I_15/2 transition in developed glasses can reach as large as 192.39 s⁻¹ and 7.14×10⁻²¹ cm², respectively. Hence, germanate glasses with superior performances might be a useful material for applications in optical amplifiers around 1.53 μm. - Highlights: • Er³⁺ doped Y₂O₃ and Nb₂O₅ modified germanate glasses were prepared. • The thermal stability and spectra properties were investigated. • The developed glasses possessed superior stability. • The stimulated emission cross-sections were calculated and discussed

[en] Highlights: • Er"3"+ doped germanate glass with good thermal stability were prepared. • Ionic boding nature was proved by bonding parameter calculation. • Mid-infrared fluorescent behaviors and energy transfer were investigated. • Rate equation and Dexter’s theory were utilized to elucidate 2.7 μm emission. - Abstract: Er"3"+ activated germanate glass with good thermal stability was prepared. Bonding parameters have been calculated and the nature of ionic bonding of the germanate glass has been determined. Mid-infrared fluorescence was observed and corresponding radiative properties were investigated. For Er"3"+:"4I_1_1_/_2→"4I_1_3_/_2 transition, high spontaneous radiative transition probability (30.09 s"−"1), large emission cross section ((14.84 ± 0.10) × 10"−"2"1 cm"2) and superior gain performance were obtained from the prepared glass. Besides, energy transfer processes concerning the 2.7 μm emission were also discussed in detail. According to simplified rate equation and Dexter’s theory, energy transfer microscopic parameters were computed to elucidate observed 2.7 μm emissions. Results demonstrate that the prepared germanate glass possessing excellent spectroscopic properties might be an attractive candidate for mid-infrared laser or amplifier

[en] Objective: To investigate the possible applicability of maternal serum human placental lactogen (HPL) and insulin levels determination for fetal health monitoring. Methods: Maternal serum HPL and insulin levels were determined with RIA in (1) 70 pregnant women clinically diagnosed as with gestational diabetes (2) 66 pregnant women with hypertension and (3) 110 normal pregnant women as controls. Results: Serum HPL and insulin levels in the women with gestational diabetes were significantly higher than those in the controls (P<0.01 ) while the levels in pregnant women with hypertension were significantly lower than those in controls (P also < 0.01). However, the differences among the fetal BPDs in the three groups were not significant (P>0.05). Conclusion: Detection of abnormally high or low levels of serum HPL and insulin in pregnant women suggested presence of maternal diseases which might affect fetal development (over weight or growth restriction). This approach was much more sensitive than conventional sonographic examination of fetus. (authors)

[en] Based on the self-consistent electron dynamic transport theory for multi-probe mesoscopic systems, we calculate the distribution of internal potential, charge density, and ac conductance of a two-probe mesoscopic conductor with wide trapezoid reservoirs, and study the contact effect. The results show that including the contact effect can make a significant difference to the frequency-dependent electron transport properties. In the nonzero frequency case, the internal potential and the charge density are complex with extremely small imaginary parts. Importantly, the imaginary part of the charge density gives rise to a real ac conductance (admittance), which corresponds to the charge-relaxation resistance

[en] Objective: To assess the clinical value of ¹⁸F-FDG PET/CT for the prediction of postoperative recurrence and metastasis in patients with NSCLC. Methods: Eighty-five patients (64 males, 21 females; average age: 58.0 years) with NSCLC were enrolled. All patients underwent ¹⁸F-FDG PET/CT within one week before surgical operation and 3 months after the operation. The diagnosis of recurrent cancer and metastasis was confirmed by pathologic findings, other imaging modalities and clinical follow-up. The diagnostic efficacy of PET/CT was calculated and the predictors for postoperative recurrence and metastasis were analyzed. χ² test and two-sample t test were used for statistical analysis. Results: Among 85 patients, 43 had recurrence and metastasis post operation. The postoperative recurrence and metastasis were detected by ¹⁸F-FDG PET/CT in 9.3%(4/43) within 6 months, 30.2%(13/43) within 1 year, 76.7%(33/43) within 2 years and 97.7%(42/43) after 2 years. The sensitivity, specificity, accuracy of ¹⁸F-FDG PET/CT for the detection of recurrent tumor and metastasis were 97.7%(42/43), 95.2%(40/42), 96.5%(82/85) respectively. The preoperative cancer staging, size and SUV_max of primary tumor were significant factors for the prediction of postoperative tumor recurrence and metastasis within 2 years (χ² = 12.360, t = 3.281 and 2.465, all P < 0.05), but not gender, age or pathological findings (χ² = 0.639, 0.012 and 3.800, all P > 0.05). Conclusions: ¹⁸F-FDG PET/CT has an important role for the detection of postoperative recurrence and metastasis in patients with NSCLC. Preoperative cancer staging, size and SUV_max of the primary tumor might be the predictive factors for postoperative tumor recurrence and metastasis within 2 years. (authors)