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Two phosphorylcarboxylic acids, 3-((bis(2-ethylhexyloxy))phosphoryl)propanoic acid (PPA) and 3-((bis(2-ethylhexyloxy))phosphoryl)-3-phenylpropanoic acid (PPPA), were synthesized for separating yttrium from other rare earths in the chloride feed of ion-adsorption type rare earth concentrate. The effect of the factors such as pH1/2, temperature, saponification degree and phase modifiers was investigated. The separation efficiencies of PPA and PPPA are obviously better than the typical extractants such as sec-octylphenoxy acetic acid (CA-12) and naphthenic acid (NA). The extraction process of rare earths by PPA and PPPA is a cation exchanging reaction, which is similar to those of CA-12 and NA. The loaded rare earths in both PPA and PPPA systems can be effectively back-extracted by 0.5 mol/L HCl or higher concentration. A cascade extraction process for separating yttrium from other rare earths was developed using PPPA as the extractant. The yttrium product with the purity of 97.20 wt% was obtained by 35 stages of extraction and 12 stages of scrubbing.

Z-scheme photocatalyst preserved with superior oxidicability is an innovative photocatalyst system that can be used for efficient photocatalytic detoxification of antibiotics. In this study, Z-scheme Ag3PO4@ZnIn2S4 photocatalyst was constructed by decorating Ag3PO4 nanoparticles on ZnIn2S4 nanoscopariums. ZnIn2S4 nanoscopariums were prepared by self-templated strategy and given hierarchical structures. The hierarchical Ag3PO4@ZnIn2S4 provides more active sites for generating photogenerated carriers and large surface area for capturing tetracycline. The study results show that Ag3PO4@ZnIn2S4 performed excellently well in the photocatalytic degradation of tetracycline and also in protecting Ag3PO4 nanoparticles from photo-corrosion. The highest removal efficiency (up to 92.3%) was achieved from the optimal composites of Ag3PO4 and ZnIn2S4. In stability tests, Ag3PO4@ZnIn2S4 did not reduce the photocatalytic activity of degrading tetracycline after five successive runs. Active radical identification proves that the transfer behavior of electron and hole over Ag3PO4@ZnIn2S4 follows a direct Z-scheme mechanism. Furthermore, the transformation pathway for degrading tetracycline was proposed by combining the Fukui index prediction with Mass Spectra identification of intermediates. This work presents in-depth sights into a regulated degradation pathway from theoretical prediction and practical identification based on innovative Z-scheme photocatalyst.

To improve the self-adaptability of MoS2 coating in different environments, the coatings were doped with functional C and Ti by unbalanced magnetron sputtering system. The clear superlattice structure with minimal modulation period was investigated by High Resolution Transmission Electron Microscope (HRTEM). The co-doped coatings have better mechanical properties due to the special structure and the formation of C–Mo, Ti–S and Ti–O bonds, and better lubrication performance in both high humidity and vacuum than those of the single-doped ones. The doped Ti not only facilitates the formation of the MoS2 (002) basal plane, but also improves the oxidation resistance of the composite film. The degree of friction-induced graphitization on the wear tracks and the quality of transfer films on the wear scars are key factors affecting the lubrication performance of the composite film. In the high-humidity environment, the reasonable doping elements can promote the formation the high-quality transfer film by interacting with H2O water molecules, which will benefit the lubrication of the coating better. Our findings deepen the understanding of MoS2 composite coating and provide a new solution for improving the self-adaptability of the coating.

A novel extractant heptylaminomethyl phosphonic acid 2-ethylhexyl ester (HEHHAP, abbreviated as H2L2) was synthesized for the extraction and separation of trivalent rare earths (REs: La ~ Lu, plus Y) from chloride medium. The results showed that the extraction of heavy REs by HEHHAP was higher than that of light one as in the order: La

Objectives Linezolid-resistant Enterococcus have spread worldwide. This study investigated the prevalence of linezolid-non-susceptible Enterococcus (LNSE) and the potential mechanism and molecular epidemiology of LNSE isolates from Nanjing, China. Methods Linezolid susceptibility of 2555 Enterococcus was retrospectively determined by Etest. Vancomycin and teicoplanin MICs were determined for LNSE by Etest. PCR and DNA sequencing were used to investigate the potential molecular mechanism. Clonal relatedness between LNSE isolates was analysed by MLST. WGS was also performed. Results A total of 27 Enterococcus isolates (24 Enterococcus faecalis, 3 Enterococcus faecium) with linezolid MICs of 4–48 μg/mL were identified, among which 20 E. faecalis and 3 E. faecium were positive for optrA. No mutations were found in genes encoding domain V of 23S rRNA or ribosomal proteins L3/L4; the cfr gene was not found. The 24 linezolid-non-susceptible E. faecalis were classified into eight STs (ST16, ST480, ST476, ST631, ST585, ST428, ST25 and ST689). The three linezolid-non-susceptible E. faecium were classified as ST17, ST400 and ST195. Comparison of the deduced OptrA amino acid sequences of the 23 optrA-positive isolates by PCR-based sequencing and WGS with that of the original OptrA from E. faecalis E349 revealed seven variants (KD, EDP, EDM, D, EDD, RDK and DP) in 16 isolates, with no mutations in the remaining 7 isolates. optrA was found downstream of fexA by searching the pE349 sequence based on WGS data. Conclusions Emergence of LNSE with optrA-mediated resistance and clonal dissemination of ST16 E. faecalis in our hospital may pose a potential public-health threat.

In the present work, an α-aminophosphonate extractant di(2-ethylhexyl) [N-(2-ethylhexyl)aminomethyl] phosphonate (Cextrant 230, L) was applied for the selective extraction and recovery of Ga(III) from the chloride solutions. The extraction of Ga(III) was compared with that of other metal ions such as Fe3+, Fe2+, Zn2+, Al3+, Mg2+ and Sn2+. The extracted complex of Ga(III) was deduced to be HGaCl4·L. The extraction equilibrium constant and thermodynamic parameters (ΔG, ΔH and ΔS) were calculated. The positive value of ΔH indicates that the extraction reaction of Ga(III) is an endothermic process. The loading capacity of 30% (v/v) Cextrant 230 for Ga(III) was determined to be 0.38 mol/L. The loaded gallium can be complete stripped by distilled water. A process was established for the selective recovery of Ga(III), by which the purity of the gallium product reached 94% with a yield of 89.5%

Production logistics is increasingly receiving attention from supply chain research. This paper focuses on the lack of quantitative approaches to assess the different operating efficiency of production logistics caused by different production modes or structures. Production logistics is first defined as a whole circulation process. Evaluation indexes are established from a perspective of major factors which make up production-logistics systems. Their computational methods are given as well. Based on the fuzzy entropy theory, an operation entropy model of production-logistics systems is developed to measure the operational efficiency of production logistics. In the case study, two operation order parameters under different conditions are calculated using the evaluation indexes and the operation entropy model developed to accurately compare the level of operational efficiency of the workshop before and after implementing cellular manufacturing. Finally, the result demonstrates the effectiveness of the proposed methodology.

Synergistic extraction of heavy rare earths (REs) were investigated in chloride media by the mixture of (2-ethylhexylamino)methyl phosphonic acid mono-2-ethylhexyl ester (HEHAMP) and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (HEHEHP). The maximum synergistic enhancement coefficients (R) of Lu, Yb, Tm, Er, Y and Ho are 2.89, 2.76, 2.54, 2.14, 2.14 and 2.06, respectively, when the mole fraction XHEHAMP is 0.5. The synergistic separation factors of the heavy REs are obtained (βY/Ho = 1.31, βEr/Y = 1.61, βTm/Er = 1.78, βYb/Tm = 1.76, βLu/Yb = 1.20). The extracted complex is determined to be RE[H(EHAMP)2][H(EHEHP)2]2 by the slope analysis method. The loading capacities of the mixtures consisting of 15% HEHAMP and 15% HEHEHP for Y and Lu are about 26.59 g/L (Yb2O3) and 27.25 g/L (Lu2O3), respectively.

Background Astragalosidic acid (LS-102) is a new water-soluble derivative of astragaloside IV - a major effective component isolated from the Chinese herb Astragali Radix. Our previous study showed that LS-102 exhibited potent cardiovascular activity. Purpose The objective of this study was to investigate the pharmacokinetic properties of LS-102 after single-dose, oral administration in beagle dogs by developing and validating an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. Method and result The chromatographic separation was performed on a Acquity HSS C18 column (100 mm × 2.1 mm, 1.8 µm) by a gradient elution using a mobile phase consisting of water and acetonitrile at a flow rate of 0.35 ml/min. The analytes were detected with a triple quadrupole tandem mass spectrometry in multiple reaction monitoring mode. Method validation revealed a wide linearity over the range of 2.0–10,000 ng/ml together with satisfactory intra- and inter-day precision, accuracy, and recovery. Stability testing showed that LS-102 spiked into dog plasma was stable for 4 h at room temperature, for up to 2 weeks at −80 °C, and during three freeze-thaw cycles. The method was effectively and successfully applied to the pharmacokinetics of LS-102 after oral administration (5, 10 and 20 mg/kg) to beagle dogs. Peak plasma concentrations are attained within approximately 2 h after oral administration with a half-life ranging from 1.55 h to 4.49 h. The plasma concentration-time curve of LS-102 after oral administration presents the phenomenon of a double-peak absorption phase. The peak concentration and area under the concentration-time curve of LS-102 seemed to increase with the increasing doses proportionally, that suggesting linear pharmacokinetics in dogs. Meanwhile, the doxorubicin (Dox)-injured H9c2 cell model was prepared by incubating the cells in 1 µM Dox for 24 h. MTT assay and LDH release measurement showed that LS-102 protected against Dox-induced cardiomyocyte death. Conclusion The obtained results may help to guide the further pre-clinical research of LS-102 as a potentially novel cardioprotective agent.

A high power gas terahertz laser based on L-shaped cavity was demonstrated. We, for the first time, investigated the output performances of D2O gas 385 μm THz laser by optimizing the output coupler transmittance of the L-shaped cavity both in theory and experiment. Under the pump energy of 1.6 J, the optimum output coupler transmittance was about 0.78 and the optimum gas pressure was about 500 Pa. Up to 8.4 mJ pulse energy at 385 μm was achieved at output coupler transmittance of 0.8, corresponding to a photon conversion efficiency of 43.7%. Pulse width of 120 ns, and beam quality factor M2 of 1.58 were obtained at the highest output energy. In addition, the experimental results are in agreement with the theoretical simulation results.

Graphene and its derivatives have been attracting the widespread interest of researchers because of their capability to improve several properties (e.g. mechanical properties, durability, anti-corrosion) of cementitious composites. This paper presents an experimental study on the influence of graphene sulfonate nanosheets (GSNSs) on mechanical properties and ablation behaviour of ferro-siliceous sacrificial cement paste and mortar, including flexural strength, compressive strength, microstructure, porosity, and thermal properties. Based on the results of differential scanning calorimetry and decomposition temperatures, the decomposition enthalpy of ferro-siliceous sacrificial cement paste and mortar was determined. It was found that, (1) the flexural strength and compressive strength of ferro-siliceous sacrificial mortar were increased by 16.22% and 24.44% respectively with the addition of 0.1 wt% GSNSs; (2) the decomposition enthalpy of ferro-siliceous sacrificial mortar was increased by 14.65%, 101.33%, and 135.15%, when adding 0.03 wt%, 0.1 wt%, and 0.3 wt% GSNSs, respectively; (3) the optimum GSNSs content was 0.1 wt% considering the mechanical strength, microstructure, and ablation rate of ferro-siliceous sacrificial cement paste and mortar. These findings can guide the design of ferro-siliceous sacrificial composites, e.g., cement paste, mortar, and even concrete containing GSNSs.

Multi-spectral imaging technology is helpful to obtain better contrast and more details of images at different wavelengths compared with monochromatic imaging or conventional RGB imaging technologies. And in resource-limited areas, microscopes with features of low-cost and portability are extremely attractive. In this manuscript, we demonstrate that cost-effective lens-less microscopy can be combined with the multi-spectral imaging technology, which can be alternative to conventional approaches and applied in biology, chemistry, environmental science. As a proof of this concept, we present a novel portable multi-spectral lens-less microscope (MSLLM). An outstanding highlight of our setup is its wavelength-self-calibrating imaging sensor (WSCIS), which can provide computationally optimized wavelength value (COWV) for LED illumination in real time. For each illumination, 5 holograms of the sample at 5 different heights are captured. Through the COWVs and phase retrieval algorithms, 7 multi-spectral images (FOV: 4.8 mm*4.6 mm, resolution: ∼1 µm) can be reconstructed. We believe that our MSLLM can be widely applied to multi-spectral microscopy in low-cost required scenes.

Fifteen polycyclic aromatic hydrocarbons (PAHs) were detected in seawater and atmosphere of Bransfield Strait. The concentration of ∑15[PAH] in the atmosphere ranged from 3.75 to 8.53 ng m−3, and three-ring PAHs were the most abundant compounds. Dissolved ∑15[PAH] in seawater ranged from 5.42 to 34.37 ng L−1, and the level of PAHs was markedly different on each side of the strait. The air–sea gas exchange process and molecular diagnostic ratios were calculated, results showed that the environmental behavior of PAHs was net deposition along this cruise. Given the changes in global transport routes of pollutants under global warming, the role of long-range transport (LRT) may be enhanced. Taking the Antarctic as a sink of PAHs due to the LRT and net deposition, PAHs will continue to load into the seawater of this area via atmospheric deposition, which contributes to improving our understanding of the environmental behavior of PAHs.

The extraction behavior of Cu(II) from chloride solution was investigated using di(2-ethylhexyl) [N-(2-ethylhexyl)aminomethyl] phosphonate (Cextrant 230, L). Cextrant 230 has a higher selectivity for Cu(II) over other divalent metal ions, e.g. Co(II), Ni(II), Mg(II) and Ca(II). The effect of the concentration of chloride ion and the extractant, aqueous pH values and temperature on the Cu(II) extraction was studied in detail. A possible extraction mechanism was proposed and the extracted complex was determined to be CuCl2·3L by the slope analysis method. Thermodynamic parameters (ΔG, ΔH and ΔS) were calculated, suggesting that the copper extraction was an exothermic process. The loading capacity of 30% (v/v) Cextrant 230 was 16.9 g Cu/L. The loaded Cu(II) can be stripped efficiently by HCl, HNO3 and H2SO4. A extraction process for the selective extraction and recovery of Cu(II) from a raffinate obtained after the recovery of rare earths from the waste NdFeB magnets was proposed, by which the purity of copper product reached 99.5% with a yield of 98.0%.

Compared to the AC application, different research should be emphasized when the superconducting fault current limiter is used in VSC-HVDC. In the AC application, over-current flowing in the superconducting will last for 45 ms–60 ms before the circuit breaker is shut down. Two or three times of the critical current of the superconducting tapes will be enough. And the heat generation will be absorbed a lot by the liquid N2 during 45 ms–60 ms. However, in HVDC situation, the time will decrease to 4 ms–10 ms and the over current could be ten times of the critical current of the tapes. This paper would explore the threshold value of the YBCO tapes in DC over-current situation and the heat transfer between the tapes and the liquid nitrogen. We obtained the relationships between time and the threshold value of over-current according to the DC over-current impulse experiments under different time conditions. The heat flux of liquid nitrogen with temperature difference was obtained by calculations. Combinations with the experiment results and the temperature-resistance curve, we got the heat transfer law. Finite element simulation model is also established in Comsol to analyze the heat transfer law between the layers during the impulse. The results will be a reference for design of the superconducting fault current limiter (SFCL).

At present, gas sensors are extremely susceptible to interference from background gases in the field environment, which leads to greatly reduced accuracy. For this reason, we propose an improved method of recovering integral absorbance (IA) using Y component of first harmonic to achieve accurate prediction of the full range of concentration (not reaching absorption saturation). This approach can eliminate the interference of background gas at a low modulation depth (m 0.25). When the background gas is pure nitrogen and a mixture of nitrogen and carbon dioxide, the recovery effect of this method on methane is both close to the theoretical value when the background gas is air. The linear fitting coefficients for the methane concentration range of 2000-7000 ppm are all greater than 0.999. The prediction effect is satisfactory regardless of the background gas, with a relative error of less than 1%. In summary, this method has considerable application prospects.

In this paper, a sequential approximate multi-objective optimization method is employed to obtain the data-driven optimal variable blank holder forces in sheet forming under interval uncertainty. Uncertain parameters driven by data are modeled as intervals, bounds of which can be easily obtained from a small number of uncertainty information. Through a nonlinear interval number programming method, the multi-objective optimization problem under interval uncertainty is converted into a deterministic one. Considering the problem of low efficiency and local optima caused by traditional optimization methods, sequential approximate optimization approach is introduced to improve the efficiency and the ability to find global optimal solutions during variable blank holder forces (VBHF) uncertain multi-objective optimization process. The presented method is applied to accurate design the variable blank holder force for a certain space large size thin-walled part forming under uncertainty. The forming quality is compared with deterministic multi-objective optimization of VBHF, and its effectiveness is proved.

With the fast development of voltage source converter based high voltage direct current (VSC HVDC) power system, an effective fault current method is in demand. In HVDC systems, the short-circuit current generally exceeds the capacity of the fast circuit breaker. Meanwhile, a superconducting fault current limiter (SFCL) is able to limit the short circuit current level. If installed in an overhead line system, SFCL has to meet the requirement of the reclosing time. The fault current is much larger than the critical current of superconducting tapes, which generates huge heat and the temperature of the tapes in the resistive type SFCL will increase sharply. After removing the fault, the tapes need certain time to recover to the superconducting state. Thus, the recovery characteristics in DC faults are an important feature of the resistive type SFCL, and they are mainly determined by the corresponding features of the superconducting tapes. In this paper, a method is presented to measure the recovery time under transient DC over current impulse. The recovery characteristics of high temperature superconducting (HTS) tapes under transient DC over current impulse are studied. The recovery time under different impulse duration and different impulse amplitude are measured by experiments. The influence factors of the recovery characteristics are discussed, which will be useful for the design of SFCL.

Background Steep inclination and excessive anteversion angles of acetabular cups could result in adverse edge-loading. This, in turn, increases contact pressure and impingement risk for traditional artificial hip joints. However, the influence of high inclination and anteversion angles on both the kinematics and contact mechanics of dual mobility hip implants has rarely been examined. Methods This study focuses on investigating both the kinematics and contact mechanics of a dual mobility hip implant under different inclination and anteversion angles using a dynamic explicit finite element method developed in a previous study. Findings The results showed that an inclination angle of both the back shell and liner ranging from 30° to 70° had little influence on the maximum contact pressure and the accumulated sliding distance of inner and outer surfaces of the liner under normal walking gait. The same results were obtained for an anteversion angle of the liner varying between −20° and +20°. However, when the anteversion angle of the liner was beyond this range, the contact between the femoral neck and the inner rim of the liner occurred. Consequently, this caused a relative rotation at the outer articulation. Interpretations This suggests that both inclination and modest anteversion angles have little influence on the kinematics and contact mechanics of dual mobility hip implants. However, too excessive anteversion angle could result in a rotation for this kind of hip implant at both articulations.

Scandium is an important member of rare earths and always associated with other metals. A novel aminophosphonate compound di-(2-ethylhexyl)[N-(2-ethylhexyl) amino methyl] phosphonate (Cextrant 230, L) was applied for the selective extraction and recovery of scandium from sulfate medium. The extraction mechanism was determined by the slope analysis method and the extracted chelate was deduced to be Sc(HSO4)SO4·2L. Thermodynamic parameters (ΔH, ΔG, ΔS) were calculated, implying that the extraction reaction of scandium is an exothermic process. Cextrant 230 was found to be an efficient extractant for the selective extraction of scandium. By just one stage extraction, the concentration of scandium in the sulfuric acid leaching of red mud decreased obviously from 3.57 mg/L to about 0.3 mg/L while the main element aluminium was nearly not extracted. A flow sheet for the recovery of scandium from red mud was proposed.

Smilax glabra (SG) is commonly used as a traditional edible herb in eastern Asia. Recently, sulfur-fumigation has been frequently used in order to obtain better color and a longer storage lifetime. However, the chemical alterations caused by this process remain unknown. The aim of this research was to explore potential chemical differences between non-fumigated and sulfur-fumigated SG samples. A novel approach was developed by using ultra-high-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UHPLC-QTOF-MS/MS) with principal component analysis (PCA) and orthogonal partial squared discriminant analysis (OPLS-DA). Fifty-eight compounds were unambiguously characterized or tentatively identified in the chemical profiles for the first time. Six newly generated sulfur-containing compounds, namely glucosyringic acid sulfate, 5-O-caffeoylshikimic acid sulfite, 3-O-caffeoylshikimic acid sulfite, 5-O-caffeoylshikimic acid sulfate, 3-O-caffeoylshikimic acid sulfate and astilbin sulfate, were screened out to be the most characteristic markers for distinguishing non-fumigated and sulfur-fumigated SG. This newly proposed approach can not only be applied for exploring chemical markers but can also be used to investigate the chemical transformation mechanism associated with sulfur for other edible herbs.