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One-Dimensional (1D) MoS 2 -decorated TiO 2 nanotubes were synthesized by the anodization of TiO 2 nanotubes followed by a hydrothermal process for MoS 2 -decoration. The structure, morphology and surface characteristics of the MoS 2 -TiO 2 composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Brunauer–Emmett–Teller (BET). The results showed that TiO 2 nanotubes can be filled and covered by flake-like MoS 2 nanostructure. The numbers of the MoS 2 layers ranged from 1 to 3. The TiO 2 nanotube sensor shows a normal n-type response to reducing ethanol gas, whereas MoS 2 -TiO 2 exhibits p-type response with excellent sensing performances. Specially, the sensitivity for the MoS 2 -TiO 2 heterojunction increased almost 11 times than TiO 2 nanotubes. This conversion of sensing behavior can be explained by the formation of p-n heterojunction structures. [ABSTRACT FROM AUTHOR]

Two types of agglomerates powder with grain sizes in the submicron- /nano-range were used as the feedstock to deposit yttria partially stabilized zirconia (YPSZ) thermal barrier coatings (TBCs). The dual-modal submicron-coating and multi-modal nano-coating were fabricated. The results from thermal shock test indicated that, due to the weak bond and higher densification rate of unmelted nano-particles in the nano-coating, the interface between recrystallization zone and unmelted nano-particles linked up, which resulted in the decrease of content of unmelted nano-particles from 13% to 7%. The weak bond and higher shrinking rate of nano-particles led to the formation of coarse cracks that ran along the recrystallization zone/unmelted nano-particles interfaces. These cracks caused the premature failure of nano-coating. The submicron-coating can overcome the inherent deficiencies of nano-coating at high temperatures and show a higher thermal shock resistance, it is expected to become a candidate for high-performance TBCs. [ABSTRACT FROM AUTHOR]

We present new numerical results in buckling failure analysis of cracked composite functionally graded plates subjected to uniaxial and biaxial compression loads. An accurate extended 3-node triangular plate element in the context of the extended finite element method (XFEM) is developed, integrating the discrete shear gap method (DSG) to eliminate shear-locking. The plate kinematics is based on the Reissner–Mindlin theory, and material properties are assumed to vary through thickness direction, obeying a power law distribution. The developed DSG-XFEM is found to be effective and accurate as it owns many desirable advantages: conveniently representing crack geometry which is independent of the mesh; shear-locking effect is no longer valid; mesh distortion is insensitive and controllable; thin plates is possible; triangular elements are easily generated for problems even with complex geometries; and high accuracy. All these arisen features are demonstrated through numerical examples and the effects of crack-length, material gradation, mesh distortion, inclined angles of cracks, boundary conditions, width-to-thickness ratio, length ratio, etc. on the critical buckling coefficient (CBC) are analyzed. Numerical results reveal that the material gradation, crack-length, thickness, length ratios, etc. have a strong effect on the behavior of CBC. This phenomenon is mainly attributed to the plate stiffness degradation due to the presence of local defects and material composition. Also, the boundary conditions greatly alter the CBC whereas the inclination of cracked angle is found to be insignificant. [ABSTRACT FROM AUTHOR]

The quaternary Cu 2 ZnSnS 4 (CZTS) is a promising material for the thin-film solar cell applications. However, because CZTS is only stabilized in a very small chemical-potential region and the defect formation is much more complicated compared to the ternary systems, it requires careful control of the thin-film solar cell preparation. We have performed a density-functional theory investigation on the intrinsic defects, defect complexes and Na doping in this complicated system. Our calculations show that the disorder and nonstoichiometry in the Cu–Zn plane induces a bandgap shrinkage of the material. From our calculated results for various defects and the doping rules, we rationalize why the experiments obtain high conversion efficiencies for the thin-film solar cells under the Cu-poor and Zn-rich conditions. The most possible defects which fulfill the experimental Cu-poor and Zn-rich conditions are V Cu , rather than Zn Cu . It is necessary to keep the Sn chemical potential moderate during the CZTS thin-film solar cell growth because the Sn-involved defects and defect complexes are generally harmful. We also find that Na doping is expected to increase the conductivity and improves the conversion efficiency of CZTS solar cells. The present study provides valuable insights into the defect physics of the complicated CZTS system and a theoretical basis for exploring its practical applications as thin-film solar cell absorbers. [ABSTRACT FROM AUTHOR]

• Mo-containing RCCAs have in general a higher σ y 1000 than those RCCAs not containing Mo. • The effect of Mo on σ y 1000 is attributed to its large χ rather than to its high T m. • The large electronegativity of Mo also favors the σ y 25 of single-bcc-phase RCCAs. Refractory complex concentrated alloys, RCCAs, show great potential for ultrahigh-temperature applications. High-temperature strength is one of the key requirements for RCCAs to qualify for that purpose. Some RCCAs already show superior high-temperature strength than that of commercial Ni-based superalloys, but many other RCCAs do not. It is thus important to identify the key factors that control the high-temperature strength of RCCAs. In this work, based on a statistic analysis of the yield strength at 1000 °C (σ y 1000) for 55 reported RCCAs, interestingly, it is revealed that Mo-containing RCCAs have in general a higher σ y 1000 than those RCCAs not containing Mo. The effect of Mo is attributed to its larger electronegativity and hence the larger electronegativity difference to other alloying elements, rather than to its higher melting point. The previously established proposal that a large electronegativity difference favoring the charge transfer and creating an atomic-level pressure that contributes to the strengthening of RCCAs at room temperature, seems effective even at a high temperature of 1000 °C. In addition, the large electronegativity difference also favors the room-temperature strength of single-bcc-phase RCCAs. The findings from this work, further verified experimentally in six new RCCAs, shed light on new research directions to develop RCCAs with decent strength at both high temperatures and room temperature, using a simple descriptor on the electronegativity difference. [ABSTRACT FROM AUTHOR]

Grain refinement increases yield strength, but usually at the cost of ductility reduction. In the present work, we explored the strategy of grain refinement and composition tuning in CoCrNi alloys to optimize mechanical properties. Grain refinement was found to strongly suppress deformation-induced martensitic transformation in metastable CoCrNi alloys, which was utilized to modulate the transformation-induced plasticity (TRIP) effect in combination with composition tuning guided by theoretical calculations. We demonstrated in a non-equiatomic CoCrNi TRIP medium-entropy alloy (MEA) that our approach resulted in an excellent combination of strength and ductility. The proposed strategy is expected to be useful in exploring superior mechanical properties of MEAs and high-entropy alloys in varying systems. [Display omitted] [ABSTRACT FROM AUTHOR]

Calcification of bones is the critical process of bone development in birds, which is very important for sustaining the normal biological function of bones. Light is one of the vital factors affecting bone development, but whether light intensity affects bone calcification and the underlying mechanism is still unknown. In this study, we used duck sternum as a model to analyze the calcification process under different light regimes. In addition, the underlying mechanism was also illustrated by integrating metabolomics and transcriptome methods. The experiment lasted from 14 to 51 d of duck age. The control group (LP1) kept light intensity 2 lx during the whole experiment. The two light supplement groups (LP2, LP3) were given light with the intensity of 70 lx at different time (14–29 d for LP2, 14–43 d for LP3). Samples were collected at 52 d of duck age. Sternal calcification analysis showed no significant difference in proportion of area of cartilage matrix and trabecular bone in keel tissue among the 3 groups, but the degree of keel calcification in LP3 was higher than in the other 2 groups. Serum metabolomics showed 32 and 28 differentially accumulated metabolites (DAMs) in the 2 comparison groups, LP1 vs. LP3 and LP1 vs. LP2, respectively. Carboxylic acids and derivatives were the most abundant among the DAMs. Sternal transcriptome analysis showed 231 differentially expressed genes (DEGs), including 177 upregulated genes and 54 downregulated genes in group LP1 vs. LP3, and 22 DEGs in group LP1 vs. LP2. Protein-protein interaction (PPI) network analysis on DEGs between LP1 and LP3 showed that genes BTRC, GLI1, BMP4 , and FOS were in the core position of the interaction network, and are also involved in bone development. KEGG pathway analysis of DAMs and DEGs showed that differences in Hedgehog signaling pathway, MAPK signaling pathway, apoptosis, energy metabolism, and amino acid metabolism following light treatment seem likely to have contributed to the observed difference in calcification of duck sternum. [ABSTRACT FROM AUTHOR]

• Influence of groundwater flow on the ground heat exchanger is reviewed. • Characteristics of analytical, numerical and experimental approaches are summarized. • Groundwater flow benefits the ground temperature recovery and heat exchanger performance. • The impact extent depends on the thickness, depth and flow rate of the aquifer. • Ignoring the groundwater flow would cause nonnegligible prediction errors. The performance of the ground heat exchanger (GHE) possesses a pivotal role in the geothermal exploitation. In recent years, a growing body of literature that recognizes the importance of groundwater flow has been presented. This article reviewed the literature dealing with the impact of groundwater flow on the GHE performance and ground temperature distribution, which were classified by analytical, numerical and experimental approaches. The characteristics of the three approaches were summarized respectively. Various GHE configurations, including U-tube, double U-tube, spiral tube, tunnel lining, horizontal spiral GHEs and GHE groups, were involved in the discussion. It was found that the groundwater flow is beneficial to the ground temperature recovery and improves the GHE heat exchange rate. The effective thermal conductivities of rocks and soils, and borehole resistances, are also affected by groundwater flow. The impact extent depends mainly on the thickness, depth and flow rate of the aquifer layer. The discussion on the collected literature demonstrated that ignoring the groundwater flow would cause non-negligible prediction errors in the evaluation of GHEs. Based on the analysis of the characteristics and applicabilities of the discussed models and methods, this review is expected to provide a more comprehensive reference for promoting the utilization of geothermal energy by GHEs. [ABSTRACT FROM AUTHOR]

Abstract: Flow behaviors and microstructures during hot compression of a Ti–43Al–4Nb–1.4W-based alloy containing β phase at various deformation conditions were investigated by physical simulations, optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The dependence of the peak stress on the deformation temperature and the strain rate can be expressed by a hyperbolic-sine type equation. The activation energy for hot deformation of the alloy is determined to be 601.7kJ/mol, which is closely related to microstructure and alloy composition. Microstructure analysis shows that both the fraction of dynamically recrystallized grains and the average size of spherical β phases increase with the decrease of Zener–Hollomon (Z) parameter. The dynamic phase transformation of β phases is apparently accelerated due to hot deformation, leading to the spheroidizing of irregular β phases. It is found that different deformation mechanisms are operated on hot deformation of the alloy, which is related to the value of Z parameter. At low Z, the dynamic softening mechanisms involve the main dynamic recrystallization (DRX) and twinning. At high Z, the DRX accompanied by the bending of lamellar colonies, γ grains and β phases would occur during hot deformation of the alloy. The existence of Y2O3 can also provide additional particle stimulated nucleation of DRX. Besides, the evolution of β phase during hot deformation plays an important role in the dynamic softening of the alloy. [Copyright &y& Elsevier]

Abstract: Objectives: This study was to explore the independent influence of menopause on cardiovascular disease (CVD) and its risk factors in rural Chinese females. Study design: This cross-sectional population-based study enrolled 2245 premenopausal and 2498 postmenopausal women aged 40–59 years in Fangshan district, Beijing, China. Data was collected by face-to-face interview, physical examination and biochemical examination during 2009 and 2010. General liner models were employed to calculate age-adjusted means of cardiovascular risk factors (CRFs). The comparisons of CVD and it risk factors according to menopausal status, and calculation of adjusted odds ratios/coefficients and their 95% confidence intervals for the associations of quartiles of elapsed time since menopause and age at menopause with CVD and its risk factors was performed by multivariate logistic/liner regression models separately. Results: After adjustment for age and other confounders, no statistically significant association of menopause with CVD was observed in our participants; however, dyslipidemia prevalence and levels of waist-to-hip ratio, triglycerides, total cholesterol and low-density lipoprotein cholesterol were presented higher in postmenopausal group, compared to the premenopausal one (P <0.05). Compared to women who had been menopausal for less than1 year, those with the elapsed time since menopause of 2–3 years had higher CHD prevalence, higher triglycerides level and lower high-density lipoprotein cholesterol level (P <0.05). Conclusions: Postmenopausal women in rural China had worse CRFs profile than the premenopausal ones, which implied menopause might aggravate the CRFs epidemic beyond effects of aging, and would increase the CVD burden during and after their middle ages. [Copyright &y& Elsevier]

Abstract: TiO2/SiO2 composite thin films deposited on various substrates have been prepared by radio frequency magnetron sputtering from a composite target. The composite films were characterized by X-ray diffraction (XRD), atomic force microscopy, X-ray photoelectron spectroscopy and water contact angel measurements. XRD analysis indicates the amorphous structures of TiO2/SiO2 composite thin films. Contact angle results show that TiO2/SiO2 composite thin films represent natural superhydrophilicity without UV irradiation due to the enhanced acidity at SiO2–TiO2 interfaces. The heat treatment is necessary to promote thermal diffusion of Si4+ or Ti4+ cations within TiO2 or SiO2 hosts. In addition, radio frequency magnetron sputtering also may play a role in the formation of hydrophilic film surfaces. [Copyright &y& Elsevier]

• A comprehensive evaluation for geothermal heating systems was proposed. • Butted well performs better considering economy, thermal efficiency and environmental impact. • Geothermal heating systems are more environmentally friendly than conventional heating. • Life cycle saving of geothermal systems is more sensitive to income and discount rate. The deep buried coaxial and horizontally-butted borehole heat exchangers are the two typical wells for geothermal utilization in space heating. The economic indexes, heat extraction performance and environmental impact of the two wells are crucial for actual projects. In this study, the Monte Carlo simulation and sensitivity analysis based on life cycle saving are employed to evaluate the economy of the two borehole heat exchanger systems. The heat extraction considering both performance and economic factors is examined by the levelized cost, while the environmental impact is assessed by the carbon intensity analysis. The results showed that the payback periods of a coaxial borehole heat exchanger system and a horizontally-butted borehole heat exchanger system are 6.7–9.2 years and 9.1–11.7 years respectively, and the life cycle saving of a butted borehole heat exchanger may reach a high value after 25 years of operation. The sensitivity of life cycle saving for both coaxial and horizontally-butted borehole heat exchangers is mainly governed by heating income, discount rate, and non-depreciable initial investment. The heat production capacity of the butted borehole heat exchanger system is 1128–1342 kW, which is twice as much as that of coaxial borehole heat exchanger. From the life cycle perspective, the levelized cost of energy and carbon intensity of the coaxial borehole heat exchanger is $ 8.67–9.35/GJ and 70.43–80.86 g(CO 2)/kWh, slightly higher than those of the butted borehole heat exchanger. It can be proved that the two borehole heat exchangers are more in line with the low-carbon policy than the traditional heating methods, and the well construction and operation phase contributes a major carbon emission from the perspective of the life cycle. [ABSTRACT FROM AUTHOR]

Abstract: Icing problems on road in Da Hinggangling forest region, northwest of China, are very serious. Many measures (blind ditch, pit for containing ice, fences/dams for blocking ice, insulated drain, etc.) have been used in this cold regions but they were not always effective. This paper analyses the formation reasons of icing and the disabled reasons of the old measures and represented a set of composite measures applied to control the icing problem on road in Da Hinggangling forest region. Results show that the frosty climate and the complex hydrology conditions and the inadequate field exploration are the main reasons that led the prevention measures to be disabled. The innovation of the technique is the “double-drainage openings” insulated drainage system. Practice proved that it had good effect on control icing problem on road, and also it could protect woods resource and ecology environment. [Copyright &y& Elsevier]

Abstract: High quality Tl2Ba2CaCu2O8 (Tl-2212) superconducting thin films are prepared on both sides of 2in. LaAlO3(001) substrates by off-axis magnetron sputtering and post-annealing process. XRD measurements show that these films possess pure Tl-2212 phase with C-axis perpendicular to the substrate surface. The thickness unhomogeneity of the whole film on the 2in. wafer is less than 5%. The superconducting transition temperatures Tcs of the films are around 105K. At zero applied magnetic field, the critical current densities Jcs of the films on both sides of the wafer were measured to be above 2×106A/cm2 at 77K. The microwave surface resistance Rs of film was as low as 350μΩ at 10GHz and 77K. In order to test the suitability of Tl-2212 thin films for passive microwave devices, 3-pole bandpass filters have been fabricated from double-sided Tl-2212 films on LaAlO3 substrates. [Copyright &y& Elsevier]

Daily dietary intakes of two naturally occurring long-lived radionuclides, 232Th and 238U, were estimated for the adult population living in a number of Asian countries, using highly sensitive analytical methods such as instrumental and radiochemical neutron activation analysis (INAA and RNAA), and inductively coupled plasma mass spectrometry (ICP-MS). The Asian countries that participated in the study were Bangladesh (BGD), China (CPR), India (IND), Japan (JPN), Pakistan (PAK), Philippines (PHI), Republic of Korea (ROK) and Vietnam (VIE). Altogether, these countries represent more than 50% of the world population. The median daily intakes of 232Th ranged between 0.6 and 14.4 mBq, the lowest being for Philippines and the highest for Bangladesh, and daily intakes of 238U ranged between 6.7 and 62.5 mBq, lowest and the highest being for India and China, respectively. The Asian median intakes were obtained as 4.2 mBq for 232Th and 12.7 mBq for 238U. Although the Asian intakes were lower than intakes of 12.3 mBq (3.0 ug) 232Th and 23.6 mBq (1.9 ug) 238U proposed by the International Commission on Radiological Protection (ICRP) for the ICRP Reference Man, they were comparable to the global intake values of 4.6 mBq 232Th and 15.6 mBq 238U proposed by the United Nation Scientific Commission on Effects of Radiation (UNSCEAR). The annual committed effective doses to Asian population from the dietary intake of 232Th and 238U were calculated to be 0.34 and 0.20 μSv, respectively, which are three orders of magnitude lower than the global average annual radiation dose of 2400 μSv to man from the natural radiation sources as proposed by UNSCEAR. [Copyright &y& Elsevier]

Abstract: Orthorhombic TmMnO3 (o-TMO) thin films have been epitaxially stabilized on (110) SrTiO3 substrates by pulsed laser deposition (PLD) technique. The microstructure and strain relaxation mechanism of o-TMO thin films are analyzed using transmission electron microscopy. It is shown that major defects in the films are misfit dislocations with Burgers vectors of type a p〈010〉 and a p〈110〉, whereas a p〈110〉 dislocations tend to dissociate into partial dislocations with Burgers vectors of type 1/2a p〈110〉. Strain in o-TMO films is relaxed by misfit dislocations as well as surface fluctuations, which is different from most of the previous studies of the perovskite thin films. [Copyright &y& Elsevier]

This method is termed Terminal branches portal vein Embolization Liver Partition Planned hepatectomy (TELPP). Of the 11 patients with hepatectomy, right hemihepatectomy(n=2), extended right hemihepatectomy (n=5), right trisecmentectomy(n=2), extended left hemihepatectomy (n=1) and left trisecmentectomy(n=1). It has the merit of ALPPS as extraordinarily rapid increasement of FLR volume, yet the morbidity and mortality is much lowe, as only single surgical operation is required. [Extracted from the article]