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Comparative politics focuses on the examination of different countries, making comprehensive descriptions and profound explanations. Among them, the difference of political culture between different countries is one of the comparable points. Based on the difference of political culture between China and the West, this paper tries to find out the reasons for the difference of political culture between China and the West and the "asymmetric cognition" in the political and cultural communication between China and the West.

Electrons with a strong reduction capacity and holes with a high oxidation capacity are retained. CO2 adsorbed on the photocatalyst surface is reduced to CH4, CH3OH and CO by electrons, and H2O is oxidized to O2 by holes.

This paper proposes an optical amplification method of measuring the minute displacement of a laser beam. The relationship between the displacement of the incident laser beam and the reflective bea...

Synchronous fluorescence spectroscopy and differential scanning calorimetry were applied to evaluate the stabilities of the peanut, corn, sunflower, and rapeseed oil. The results showed that when t...

Oxyfluoride silicate glasses co-doped with Cr3+ and Yb3+ ions were fabricated in this work. High △T (178–214 °C) value demonstrated that the thermal stability of the prepared glasses were better than tellurite and germanate glasses. X-ray diffraction (XRD) curves proved the amorphous nature of the glasses, the energy dispersive spectroscopy (EDS) analysis and Fourier Transform infrared spectroscopy (FT-IR) curves explored the network structure of glasses. The photoluminescence excitation (PLE) and photoluminescence emission (PL) spectra show that the glasses absorption peaks located at 430 nm (Cr3+:4A2g - 4T1g (P)) and 627 nm (Cr3+:4A2g - 4T2g), while the emission peak close to 1010 nm (Yb3+:2F5/2 -2F7/2), which meets the condition of energy down-conversion. Besides, the energy transfer efficiency (ηCET = 33.5%) and the quantum cutting efficiency (ηQE = 133.5%) were calculated from the measured decay curves. These values were higher than Cr3+/Yb3+ co-doped fluorosilicate glass with incorporating of CaF2 (21.5% and 123.5%) and Tb3+/Yb3+ oxyfluoride glass (13.5% and 113.5%), indicating the prepared samples are conducive to the energy transfer from Cr3+ to Yb3+ ions. The experimental results reveal that the oxyfluoride silicate glasses have potential application prospects in crystalline silicon (c-Si) solar cells.

Ho3+/Yb3+ co-doped tellurite–germanate glasses with lower phonon energy (771 cm−1) were prepared by conventional melt-quenching method. The prepared samples were characterized by emission spectra, differential scanning calorimeter (DSC) curve, X-ray diffraction (XRD) pattern, and Raman spectra. The DSC curve shows that the sample has a good thermal stability, in which the ΔT is 202 °C. Compared to the recently reported tellurite glasses, the ΔT was increased by approximately 24%. Under the 980 nm laser excitation, it was found that the full width at half maximum (FWHM) of the sample at 2.0 µm was 190 nm. Compared with the reported glasses for this type, the value was effectively improved. Meanwhile, the FWHM of the sample at 4.1 µm was 285 nm, which has not been reported yet. This indicates that Ho3+/Yb3+ co-doped tellurite–germanate glass has a great application prospect in mid-infrared broadband fiber amplifiers.

Fluorotellurite glasses tri-doped with Tm 3+ , Er 3+ and Bi ions were investigated. The measured parameter ΔT (116 °C) confirmed that the prepared glasses had good stability. An ultra-broadband fluorescence emission (950–1670 nm) was observed with a full-width at half-maximum (FWHM) of 560 nm, which covered the entire bands of O, E, S, C, L and U. The 1800 nm fluorescence intensity of Tm 3+ /Er 3+ co-doped and Tm 3+ /Er 3+ /Bi tri-doped glasses was enhanced compared to Tm 3+ doped glass, which indicates that there is energy transfer between Tm 3+ , Er 3+ and Bi ions. The maximum fluorescence lifetime of the prepared glasses was 7.39 ms, indicating the excellent fluorescence performance at 1800 nm. Additionally, the maximum absorption cross section (σ abs = 1.77 × 10 −20 cm −2 ) and emission cross section (σ em = 7.61 × 10 −20 cm −2 ) suggest that the Tm 3+ /Er 3+ /Bi tri-doped glasses have good optical absorption properties and high gain fluorescence emission. The above results indicate that the Tm 3+ /Er 3+ /Bi tri-doped fluorotellurite glasses have good application prospects in the field of fiber amplifiers and near-infrared lasers.

High-temperature photovoltaics (PV) for terrestrial and extraterrestrial applications have presented demanding challenges for current solar cell materials, such as Si, III–V AlGaInP, and II–VI. Wid...

Y2O3 and La2O3 co-doped silicate glasses were prepared by conventional melt-quenching method. The effects of Y2O3 and La2O3 contents on the structural, thermal and mechanical properties of glass samples were investigated by X-ray diffraction (XRD), Differential scanning calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR). The results showed that the prepared glass samples exhibited excellent mechanical properties and thermal stability. The hardness, elastic modulus and ΔT reaches 860HV, 108 GPa and 299 °C, respectively. Compared with the reported glasses for this type, these values were increased by approximately 19.5%, 28% and 8.7%, respectively. In addition, the transmittance of all glass samples exceeds 90% in visible spectra range. The above results indicate that the prepared glass samples can be applied to the fields of architectural glass, automotive windshield and screen of electronic products.

2.7 μm fluorescence of Er3+ single doped glass and Er3+/Bi3+ co-doped glasses are obtained when excited by a 980 nm laser diode. The fluorescence emission intensity from Er3+ is enhanced significantly by doping Bi3+ in tellurite glass. In comparison with the single doped Er3+, the emission intensity increased by 17.8%. The measured parameter ΔT(154.8℃)＞130 ℃ indicates that compared with Er3+/Nd3+ co-doped tellurite glass and Tm3+ doped lead silicate glass, there is a better resistance to crystallization and thermal performance in Bi3+ doped tellurite glass. The enhanced 2.7 μm fluorescence emission of sample with the introduction of Bi3+, which may be caused by energy transfer between Bi3+ and Er3+.Above all, Strong 2.7 μm emission and good thermal properties reveal that the Bi3+/Er3+ co-doped glass may be a potential material to improve 2.7 μm laser performance of Er3+.

We observe a degradation of the minority-carrier lifetime in silicon substrates after a temperature cycle in a molecular beam epitaxy (MBE) chamber that is representative of the growth of III–V materials. This decrease in the lifetime is from milliseconds to microseconds, and in some cases into the sub-microsecond range. The degradation appears to be caused by thermally activated diffusion of metals from the back side of the substrate, occurring at temperatures above 500 °C. This impacts the ability to achieve high-performance monolithic III–V/Si multi-junction solar cells, since the epitaxial growth usually requires high-temperature steps (over 700 °C) for surface de-oxidation or surface reconstruction and temperatures of 400–600 °C during the epitaxial growth. We show that, through phosphorous diffusion gettering, the lifetimes of degraded wafers can be recovered to the millisecond range. Further, we demonstrate that a silicon nitride coating functions both as a diffusion barrier and as an interfacial gettering or hydrogenation agent, enabling high minority-carrier lifetimes directly out of the MBE chamber. This approach allows for the silicon minority-carrier lifetime to be maintained in the millisecond range without the need for post-growth recovery, providing a path to achieve high-efficiency III–V/Si solar cells.

GaN 0.02 P 0.98 is a promising top junction material for a Si-based tandem solar cell, offering the correct lattice constant and bandgap for an optimal three-terminal device. A key challenge for dilute nitride materials is achieving sufficiently high carrier lifetimes. This paper presents a detailed investigation of the carrier lifetimes in GaNP lattice matched to Si as well as a novel hydrogenation treatment. The lifetimes are over 20 ns at 10K, but the TRPL signal becomes undetectable at 140K due to increased nonradiative recombination. While annealing boosts the carrier lifetime, subsequent hydrogenation was seen to neither increase nor decrease lifetime.

Titanium dioxide (TiO2) is of great interest as anode material for lithium-ion batteries (LIBs) because of its safety, structure stability, and low cost. However, the limitations of low conductivity and small theoretical capacity prevent its further applications. Herein, TiO2 nanospheres with a hollow structure (H-TiO2) were successfully synthesized via a hard-template method. The resultant material used as LIBs anode with superior lithium storage properties in terms of high initial capacity (∼289 mA h g−1 at 0.1 A g−1), good rate capability (∼101 mA h g−1 at 2 A g−1), and excellent cycling stability (∼196 mA h g−1 was retained over 300 cycles at 0.1 A g−1). The improved performances are attributed to the large specific area (~225 m2 g−1) and abundant mesoporous of the hollow structure, which can not only promote the diffusion of Li+ and e− but also achieve an increase in the contact area between electrodes and electrolyte.

This work reports on the growth of dilute nitride GaPN x lattice-matched to Si as a pathway for Si-based multijunction solar cells. GaPN x layers were grown using a plasma assisted molecular beam epitaxy with varying N concentrations. High resolution X-Ray ray diffraction analysis revealed high structural quality of the grown thin-film layers including the successful integration of GaPN x with a GaP buffer layer on Si substrate. Low temperature photoluminescence spectroscopy results showed the peak position to be around 1.94eV at 100K for the lattice-matched case. This value is close to the ideal bandgap for independent connection with Si bottom cell in a tandem configuration.

Smarting surface coatings have been shown to be good examples to cope with the drastic volume change and poor conductivity of SiO2 anode. Herein, we successfully synthesize the SiO2@a-TiO2@Ag composite with core–shell structure via a facile sol-gel method. The designed structure, in which a-TiO2 layer show elastic behavior, can alleviate the expansion of electrode, and provide more diffusion channels for lithium-ion. In addition, Ag nanoparticles are good conductor of electricity. The resulting materials used as lithium-ion batteries anode with superior lithium storage properties in terms of high initial capacity (1320 m Ah g−1 at 0.1 A g−1), good rate capability (425 m Ah g−1 at 2 A g−1), and excellent cycling stability (712 m Ah g−1 was retained over 300 cycles at 0.1 A g−1).

This work investigates defect formation and evolution associated with the deposition of GaP layers on precisely oriented Si(0 0 1) substrates. The GaP layers were grown with thicknesses ranging from ∼37 nm to ∼2 µm at a growth rate of 0.52 μm/hr using molecular beam epitaxy (MBE). The crystallinity of thin (37-nm) MBE-grown GaP layers was also compared with thin GaP layers grown by migration-enhanced epitaxy (MEE). The MBE growth procedure was shown to postpone relaxation of the epitaxial GaP layers up to a thickness of ∼250 nm. Detailed analysis of high-resolution X-ray diffraction patterns and comparison with cross-sectional transmission electron micrographs clarified the defect formation mechanism. Thin GaP layers showed very low defect densities except for anti-phase boundaries, whereas substantial threading defects predominated in the thicker, noticeably relaxed structures.

Aggregation of the misfolded scrapie prion protein (PrPSc) is known to cause neurodegenerative diseases. In this paper, we have investigated the stability of PrPC by combining coarse-grained model and all-atom molecular simulations. Our results show that the unfolding of PrPC starts from the opening of the folded domain with α1 moving away from α2α3 domain, and then arrives at a metastable intermediate, and forms a more stable dimer complex in the end. This work unravels the mechanism of the early stage of conformational conversion and dimerization of prion protein and provides significant hints for the development of anti-prion therapeutics.

Sb-based alloys offer great potential for photovoltaic and thermophotovoltaic applications. In this paper, we study the performance of AlxGa1-xSb (x = 0, 0.15, and 0.50) single-junction solar cells over a temperature range of 25–250 °C. The dark current-voltage, one-sun current-voltage, and external quantum efficiency measurements were acquired at different temperatures. Correlations between experimental and numerical results are made to draw conclusions about the thermal behavior of the cells. It is shown that, while the bandgaps decrease linearly with temperature leading to the reduction of open-circuit voltages, the short-circuit current densities decrease with non-linear trends. The temperature-dependent dark current densities were extracted by fitting the dark current-voltage curves to single- and double-diode models to give an insight into the effect of intrinsic carrier concentration (ni) on the cell performance. We find that the ni has a significant impact on temperature-dependent cell performance. These findings could lay a groundwork for the future Sb-based photovoltaic systems that operate at high temperatures.

We demonstrate an efficient and compact ultraviolet laser at 303 nm generated by intracavity frequency doubling of a continuous wave (CW) laser diode-pumped Pr3+:YLiF4 laser at 607 nm. A cesium lithium borate (CLBO) crystal, cut for critical type I phase matching at room temperature, is used for second-harmonic generation (SHG) of the fundamental laser. By using an InGaN laser diode array emitting at 444.3 nm with a maximum incident power of 10 W, as high as 68 mW of CW output power at 303 nm is achieved. The output power stability in 4 h is better than 2.85%. To the best of our knowledge, this is high efficient UV laser generated by frequency doubling of an InGaN laser diode array pumped Pr3+:YLiF4 laser.