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Mercury (Hg) in aquatic ecosystems is of great concern due to its toxicity, bioaccumulation, and magnification in the food web. The Tibetan Plateau (TP) is endowed with the highest and largest lakes on earth, whereas Hg distribution and behavior in lake waters are least known. In this study, surface water samples from 38 lakes over the TP were collected and determined for the total Hg (THg) concentrations. Results revealed a wide range of THg concentrations from

In this work, a novel Mn4+ doped BaTiOF4 oxyfluoride red-emitting phosphor was fabricated through a two-step wet chemical synthesis on a large scale at an ambient temperature. The crystal structure, morphology, and elemental composition were confirmed by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and energy dispersive X-ray fluorescence spectrometer respectively. The luminescence properties were investigated from emission, excitation and ultraviolet–visible diffuse reflectance (DRS). The as-prepared BaTiOF4:Mn4+ product is well crystallized into single orthorhombic phase with particulate morphology and presents sharp red emission lines locating around 631 nm under illumination at 470 nm blue light. The single red LED, based on the novel BaTiOF4:Mn4+ phosphor exhibits bright red color with CIE chromaticity coordinate values of x = 0.692 and y = 0.308, revealing it may find application in LED backlighting.

In this work, a novel fluoroaluminate red phosphor of Cs2NaAl3F12:Mn4+ with excellent color purity was fabricated via the introduction of Mn4+ in the octahedral center. The crystal and electronic structures, luminescence properties and optical performances were characterized and investigated in detail. The evidences showed that Cs2NaAl3F12:Mn4+ well-crystallized into a single phase with particulate morphology, and the non-equivalent occupation in Cs2NaAl3F12 resulted in sharp red emissions with improved color purity upon blue light illumination. For solid-state lighting, the optical parameters consisted of the “blue-yellow-red” contributions significantly improved to a high color-rendering index of 88.7 and a low color temperature of 3856 K, indicating the potential use of Cs2NaAl3F12:Mn4+ for warm white light-emitting diode applications.

Additional file 1: Supplementary Table S1. Primer sequences for qRT-PCR. Supplementary Table S2. Sensitivity, specificity, AUC of tRF-5026a and tiRNA-5034-GluTTC-2 in tissues and plasma samples and their combination. Supplementary Table S3. The relationships between the expression levels of tRF-5026a (ΔCq) in tissues and the clinicopathological factors of patients with gastric cancer. Supplementary Table S4. Univariate and multivariate Cox regression analysis of the overall survival of tRF-5026a expression in patients with gastric cancer tissues. Supplementary Fig. S1. The use of tRF-5026a mimic and inhibitor to modulate its levels in normal gastric mucosal epithelial cells and gastric cancer cells. a The up-regulation effect of tRF-5026a mimic. b The down-regulation effect of tRF-5026a inhibitor. nc, negative control; n=3, * P

Due to the limited utilization of electrode materials, the rational design and facile synthesis of composite structures are still challenging issues for lithium-ion batteries (LIBs). Herein, a simple approach has been developed to prepare multiple core–shell structures of ZnO nanoparticles (NPs) encapsulated in hollow amorphous carbon (AC) shells. The as-synthesized ZnO@AC composites showed a uniform dispersion of ZnO NPs, compliant buffer AC shells, and nanoscale void spaces between the ZnO NP cores and AC shells. As a result of their structural merits, the ZnO@AC composites were evaluated as anode materials for LIBs and delivered enhanced coulombic efficiency, high reversible capacity, high rate capability, and improved cycling stability.

This work presents the rapid electrodeposition of Fe&ndash, Ni alloy foils from chloride baths containing trivalent iron ions at a low pH (&lt, 0.0). The effect of the concentration of Ni2+ ions on the content, surface morphology, crystal structure, and tensile property of Fe&ndash, Ni alloys is studied in detail. The results show that the co-deposition of Fe and Ni is controlled by the adsorption of divalent nickel species at low current density and the ionic diffusion at high current density. The current density of preparing smooth and flexible Fe&ndash, Ni alloy foils is increased by increasing the concentration of Ni2+ ions, consequently the deposition rate of Fe&ndash, Ni alloy foils is increased. For example, at 0.6 M Ni2+ ions, the current density can be applied at 50 A&middot, dm&minus, 2, along with a high deposition rate of ~288 &mu, m&middot, h&minus, 1.

A citrate–ammonia bath was selected to electrodeposit Fe–W alloys, which exhibit a crystalline structure even if the content of W in the Fe–W alloy is up to 37.8[Formula: see text]wt%. Those alloys could be oxidized partly at 700[Formula: see text]C. Resultant oxides were composed of Fe2O3, Fe3O4 and amorphous products. The composite oxides presented better electrochemical properties than those of the Fe2O3 and Fe3O4 composite formed by oxidation of Fe deposits. For instance, such an electrode demonstrates the reversible capacity of up to 2438.3[Formula: see text]mAh[Formula: see text]g[Formula: see text] (in terms of incremental oxygen) after 100 charge–discharge cycles, while the electrodes of Fe2O3 and Fe3O4 composites formed by oxidation of Fe deposits were of only 667.5[Formula: see text]mAh[Formula: see text]g[Formula: see text].

The technological conditions of absorption of H2S using pyrolusite ferric sulfate were studied. In this process, low cost raw materials are used, oxidation absorption of H2S and regeneration of ferric salt were realized simultaneously, and continuous operation can be achieved. Consequently, appropriate operating conditions were established: Room temperature; Concentration of sulfuric acid is 0.5 mol/L; Ferric concentration is 1.0 mol/L; Concentration of MnO2 is 3.0g /50mL. Under these conditions, the maximal ratio of absorption of 99.2% can be achieved in discontinuous operation process, and approximately 100% absorption of H2S can be achieved by multi-absorption in series and addition of pyrolusite and sulfuric acid in continuous operation process.

By using the perturbation method, an effective nonlinear direct current (DC) and alternating current (AC) response of nonlinear composites with cylindrical coated inclusions randomly embedded in a host medium is studied under the action of an external electric field Ea=E0 + E1 sinωt+E3 sin3ωt with different amplitudes and frequencies. The local potentials of composite at all harmonics are given in the inclusion core, the coated layer and the host regions. All effective nonlinear responses of composites and the relationship between the effective nonlinear responses at all harmonics are also deduced for the cylindrical coated inclusions in a dilute limit.

Dissolved organic carbon (DOC) in snow plays an important role in river ecosystems that are fed by snowmelt water. However, limited knowledge is available on the DOC content in snow of the Chinese Altai Mountains in Central Asia. In this study, DOC in the snow cover of the Kayiertesi river basin, southern slope of Altai Mountains, was investigated during November 2016 to April 2017. The results showed that average concentrations of DOC in the surface snow cover (1.01 ± 0.52 mg L−1) were only a little higher than those in glaciers of the Tibetan Plateau, European Alps, and Alaska, but much higher than in Greenland Ice Sheet. Depth variations of DOC concentrations from snowpack profiles indicated higher values in the surface layer. During the observation period, scavenging efficiency for DOC in snow cover is estimated to be 0.15 ± 0.10, suggesting that DOC in snow can be affected more by the meltwater during ablation season than during accumulation season. The average mass absorption cross section at 365 nm and the absorption Ångström exponent of DOC were 0.45 ± 0.35 m2 g−1 and 2.59 ± 1.03, respectively, with higher values in March and April 2017. Fraction of radiative forcing caused by DOC relative to black carbon accounted for about 10.5%, implying DOC is a non-ignorable light-absorber of solar radiation in snow of the Altai regions. Backward trajectories analysis and aerosol vertical distribution images from satellites showed that DOC in the snow of the Altai Mountains was mainly influenced by air masses from Central Asia, Western Siberia, the Middle East, and some even from Europe. Biomass burning and organic carbon mixed with mineral dust contributed significantly to the DOC concentration. This study highlights the effects of DOC in the snow cover for radiative forcing and the need to study carbon cycling for evaluation of quality of the downstreams ecosystems.

Deposited mineral dust and black carbon are known to reduce the albedo of snow and enhance melt. Here we estimate the contribution of anthropogenic black carbon (BC) to snowmelt in glacier accumulation zones of Central Asia based on in-situ measurements and modelling. Source apportionment suggests that more than 94% of the BC is emitted from mostly regional anthropogenic sources while the remaining contribution comes from natural biomass burning. Even though the annual deposition flux of mineral dust can be up to 20 times higher than that of BC, we find that anthropogenic BC causes the majority (60% on average) of snow darkening. This leads to summer snowmelt rate increases of up to 6.3% (7 cm a−1) on glaciers in three different mountain environments in Kyrgyzstan, based on albedo reduction and snowmelt models., Scientific Reports, 7, ISSN:2045-2322