[en] NaYF_4:Yb"3"+/Er"3"+ with different phases, morphologies, and luminescent properties were synthesized using a facial hydrothermal method. The as-obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) pattern, and photoluminescence (PL). The XRD results indicated that ethylene diamine tetraacetic acid (EDTA) and citrate play an important role in phase transition at low reaction temperatures. SEM images revealed that samples morphologies can be changed from irregular shapes to regular microprisms by EDTA and citrate. TEM images showed that the diameter of samples synthesized at 120 °C without any chelating agents is ∼50 nm. HRTEM indicated that the crystal grows along the [111] plane. The selected area electron diffraction (SAED) pattern showed that the nanoparticles have a good single-crystalline structure. FL spectra revealed that citrate can reduce the luminescence intensity at any reaction temperature. However, EDTA can improve optical properties at low reaction temperatures. - Highlights: • Effect of EDTA and citrate on upconversion luminescence was investigated. • EDTA & citrate can promote phase transition from cubic to hexagonal. • EDTA can improve the emission intensity at low reaction temperatures. • EDTA & citrate play a role in changing crystals’ growth direction.

[en] Highlights: • An indirect SHTR with integrated special shaped heat pipe was proposed. • The frozen start-up process of the HTSSHP was compared with traditional LMHPs. • The relation between transition temperature and temperature variation rate was studied. • The potential application of the HTSSHP in solar conditions was studied and proved. - Abstract: Renewable but intermittent solar energy, typically marked as a sustainable chemical fuel, has been tremendously used to drive high-temperature thermochemical processes via concentrated solar irradiation. Thus, a novel solar thermochemical reactor which integrated with a high temperature special shaped heat pipe (HTSSHP) using sodium as the working fluid is proposed. The HTSSHP includes a flat disk-shape evaporator and multiple cylindrical condensers. The frozen start-up performance of a second generation of HTSSHP with wall thickness reduction has been tested in an electric heater which showed that the frozen start-up process of the HTSSHP is different from the flat-front model of most traditional liquid metal heat pipes, but the continuum vapor flow regime transition velocity is in the same level. Meanwhile, the transition temperature doesn’t appear with the peak value of temperature variation rate, but at the down peak with about 10–25 °C/min for heat flux of 82.5 kW/m"2. The second generation of HTSSHP can start up successfully under tested heat fluxes and inclination angles without any heat transfer limits occurred, which shows the feasibility of operating HTSSHP under solar dish conditions. Meanwhile, the start-up time is largely reduced compared with the first generation, and it is about 41 min under heat flux of 82.5 kW/m"2.

[en] Amorphous hydrogenated carbon nitride thin films (α-C_xN_y: H_1-x-y) were synthesized by external capacitive coupling low pressure plasma chemical vapor deposition (LPPCVD) with CH₄, N₂ and H₂ gases. The deposition rate and optical properties of the deposited CHN films were systematically analyzed as a function of radio power. The morphology of the films was investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The chemical structure and elemental composition of the CHN films were characterized by Fourier transform infrared spectroscopy (FTIR). The FTIR investigation demonstrates the presence of carbon-nitrogen bonds with hydrogenated components in the films. And its optical gap ranges from 1.953-2.359 eV, and the optical gap becomes narrower with the incident power increasing. (authors)

[en] To improve the biological performance of poly(ethylene glycol)-diacrylate (PEGDA) hydrogel as an injectable bone grafting scaffold, sodium methallyl sulphonate (SMAS) was incorporated into PEGDA hydrogel. The physiochemical properties of the resultant polymers were assessed via Fourier transform infrared spectroscopy (FTIR), swelling ratio, zeta potential, surface morphology, and protein adsorption analysis. MC3T3-E1 cells were seeded on the hydrogel to evaluate the effect of the sulphonated modification on their attachment, proliferation, and differentiation. The results of FTIR and zeta potential evaluations revealed that SMAS was successfully incorporated into PEGDA. With increasing concentrations of SMAS, the swelling ratio of the hydrogels increased in deionized water but stayed constant in phosphate buffered saline. The protein adsorption also increased with increasing concentration of SMAS. Moreover, the sulphonated modification of PEGDA hydrogel not only enhanced the attachment and proliferation of osteoblast-like MC3T3-E1 cells but also up-regulated alkaline phosphatase activity as well as gene expression of osteogenic markers and related growth factors, including collagen type I, osteocalcin, runt related transcription factor 2, bone morphogenetic protein 2, and transforming growth factor beta 1. These findings indicate that the sulphonated modification could significantly improve the biological performance of PEGDA hydrogel. Thus, the sulphonated PEGDA is a promising scaffold candidate for bone grafting.

[en] Amorphous hydrogenated carbon films were prepared by pulsed laser deposition (PLD) and the effect of the hydrogen pressure upon the performance of the films was studied. The AFM and Wyko images of the film show that the surfaces of the films are smooth and compact and that as the hydrogen pressure increases, the roughness becomes higher. The Raman spectra of the films were analyzed and it shows that the G peak and D peak approach to higher wave numbers as the hydrogen pressure increases. Fouorier transform infrared spectroscopy indicates that there exist sp³-CH₃ and sp²-CH clusters in the film. With floating method of PLD, self-supporting CH films with different thickness (100 ∼ 300 nm) were synthesized. (authors)

[en] The current-voltage characteristic of hydrogen plasmas induced by helicon waves was measured in situ by a Langmuir probe under low pressure. According to Druyvesteyn method, raw data were fitted by an exponential transformation to a tangent hyperbolic function. Electron density, effective electron temperature and electron energy probability function (EEPF) were calculated from the fitted curves. The variation law of electron density, effective electron temperature and EEPF was analyzed in relation to different experimental parameters. The results demonstrate that RF power, gas pressure and controlled magnetic field relation to different experimental parameters. The results demonstrate the RF power, gas pressure and controlled magnetic field have significant effects on state parameters of plasma. Electron density jumps with the increase of RF power because of the transition of mode, and it increases linearly with controlled magnetic field. With the increase of gas pressure, a peak is observed in the variation of electron density at 1.5 Pa. Effective electron temperature decreases with the rise of RF power and pressure, With the enhanced magnetic field, effective electron temperature descents linearly. Both peaks and higher energy parts of EEPF curves move toward lower energy. (authors)

[en] To develop a convenient and rapid single-kidney CT-GFR technique. One hundred and twelve patients referred for multiphasic renal CT and 99mTc-DTPA renal dynamic imaging Gates-GFR measurement were prospectively included and randomly divided into two groups of 56 patients each: the training group and the validation group. On the basis of the nephrographic phase images, the fractional renal accumulation (FRA) was calculated and correlated with the Gates-GFR in the training group. From this correlation a formula was derived for single-kidney CT-GFR calculation, which was validated by a paired t test and linear regression analysis with the single-kidney Gates-GFR in the validation group. In the training group, the FRA (x-axis) correlated well (r = 0.95, p < 0.001) with single-kidney Gates-GFR (y-axis), producing a regression equation of y = 1665x + 1.5 for single-kidney CT-GFR calculation. In the validation group, the difference between the methods of single-kidney GFR measurements was 0.38 ± 5.57 mL/min (p = 0.471); the regression line is identical to the diagonal (intercept = 0 and slope = 1) (p = 0.727 and p = 0.473, respectively), with a standard deviation of residuals of 5.56 mL/min. A convenient and rapid single-kidney CT-GFR technique was presented and validated in this investigation. (orig.)

[en] Highlights: • Silver concentrations in biosolids across China range from 0.64 to 7.47 mg kg^{− 1}. • Silver was higher in wheat with biosolids amendment under rice-wheat rotations. • Silver accumulation in crops is mainly affected by water content and species. There have been numerous studies simulating the behaviour and fate of silver (Ag) applied to soils in biosolids in recent decades but the results remain to be verified under actual farming conditions. Here, we report a study of the transfer of Ag along the biosolids-soil-crop pathway with repeated biosolid applications over a four-year period to three contrasting soil types under rice-wheat rotation cultivation. A systematic investigation of Ag concentrations in biosolids throughout China shows Ag concentrations ranging from 0.64 to 7.47 mg kg^{− 1} with a mean value of 3.58 mg kg^{− 1} and a median of 3.02 mg kg^{− 1} on a dry weight basis. Silver concentrations were significantly higher in industrial biosolids than in domestic or mixed flow biosolids. Biosolids application enhanced Ag accumulation in whole wheat. Silver concentrations in whole wheat increased to 20.8, 20.5 and 4.87 μg kg^{− 1} after four years of high-metal industrial biosolids application to an acid Typic Ali-Perudic Aragsol, a neutral Typic Hapli-Stagnic Anthrosol, and a calcareous Typic Carbonati-Perudic Ferrosol, respectively. Moreover, the Ag translocation factor also increased in wheat following biosolids application with values of 5.6, 3.1 and 1.4, respectively. However, Ag accumulation in rice was found only in the acid soil with no discernible increase (p > 0.05) in the translocation factor. The seasonal redox cycle may contribute to this phenomenon. A seedling incubation experiment confirms the influence of soil water regime on Ag bioavailability with a higher Ag translocation factor during the wheat growing season than the rice growth period. Incorporating a fallow period during the wheat (winter crop) season might be a suitable strategy for repeated biosolids application.

[en] Highlights: • A solar reactor coupled with sodium heat pipe was tested with a solar simulator. • The radiative power of the high flux solar simulator was measured and calibrated. • The solar thermal conversion efficiency of the reactor can achieve 90%. • The solar reactor has shown good heat absorbing and transfer abilities. -- Abstract: Solar thermochemical reactor is the key to store solar energy as chemical basic fuels through high temperature chemical reactions. The thermal performance of a solar high temperature thermochemical reactor coupling heat pipe technology has been preliminary performed under a high-flux solar simulator. The radiative power of the solar simulator was measured and calibrated with an infrared camera and an optical meter. The measurement indicates an average heat flux exceeding 130 kW/m² over a 210-mm-diameter focal plane. The temperature characteristics and thermal performance of the reactor with only nitrogen cooling were investigated under various nitrogen flow rates and heat flux inputs. It is showed that the input heat flux has effect on the reactor temperature and the temperature distribution on heating surface is associated with the radiative flux distribution from the solar simulator. The heating surface temperature is at the range of 850–1075 K for the input heat flux of 55.5–108.8 kW/m² and cooling gas flow rate less than 33 m³/h. The gas out temperature obtained is lower than 700 K with room temperature inlet. The radiation heat loss through heating surface accounts for 45–60% of the radiative power incident on the reactor. The thermal efficiency of STPCR is greatly influenced by cooling gas flow rate and it is in the range of 27–90% with cooling gas flow rate from 5 m³/h to 33 m³/h. Whereas the thermal efficiency appears less influenced by heat flux inputs. Good heat absorbing and transfer abilities of the reactor has been shown.

[en] Highlights: • Novel method of PBDEs based on BrO⁺ reaction product ion and double mass selection using GC-ICP-MS/MS instrumentation. • The most suitable reaction gas was selected by product ion scans. • The Ar-based polyatomic interference on Br⁺ in ICP-MS was dealt with N₂O reaction mode. • Accurate determination of ultra-trace levels of PBDEs in fish tissue. -- Abstract: Gas chromatography inductively coupled plasma triple quadrupole mass spectrometry (GC-ICP-MS/MS) operated in N₂O reaction mode (mass-shift mode) was established for the analysis of six congeners of polybrominated diphenyl ethers (PBDEs): BDE 28, BDE 47, BDE 99, BDE 100, BDE 153 and BDE 154 in fish samples. The spectral interference on the determination of PBDEs was eliminated by measuring the product ion (BrO⁺) instead of traditional methods measuring Br⁺. After comparing the signal intensities of the three reaction gases (O₂, H₂, and N₂O), the highest sensitivity was found using N₂O as the reaction gas. The results showed that bromine is an element that suffers from strong spectral overlap in ICP, mainly from Ar-based polyatomic interferences. Spectral interference was assessed by measuring the bromine isotope ratio of ⁸¹Br⁺ and ⁷⁹Br⁺ of the six priority PBDEs in the He collision mode and N₂O reaction mode, respectively. In the conventional He collision mode, the relative isotope ratio of ⁷⁹Br/⁸¹Br (the measured isotope ratio to the natural isotope ratio) of the analytes ranged from 0.955 to 0.965, which proves that using He as the collision gas cannot completely eliminate the spectral interference. In the N₂O reaction mode, the relative isotope ratio of ⁷⁹Br/⁸¹Br ranged from 0.991 to 1.004, demonstrating that spectral interference can be fully eliminated. Samples were processed using the modified QuEChERs method with detection limits ranging from 0.03 to 0.09 ng g⁻¹ with a relative standard deviation of less than 3%. Six priority PBDEs in the NIST reference materials SRM 1947 (frozen fish tissue homogenate) were determined by mass-shift mode to verify this conclusion. No statistically significant difference was observed between the measured value and the certified value, with recoveries between 95% and 114%. The method was applied to the analysis of PBDEs in marine fish samples and five PBDEs were observed (BDE28,BDE-47, BDE-99, BDE-100 and BDE-153) at concentrations ranging from 0.04 to 0.54 ng g⁻¹.