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Metal organophosphonates have been explored in energy-related fields due to their high chemical and thermal stability as a type of uniformly precursor, but only few of pristine metal organophosphonate are directly used for oxygen evolution reaction (OER) catalysts. Here, a mixed-valence iron phosphonate (Fe3-ppat) has been constructed and applied to OER catalysis considered the potential active sites in pillars FeII(H2O)4(COO)2 and inorganic layers FeIII(μ2–OH)PO3. Specifically, isostructural trimetallic framework Fe1.7Co0.3Ni1.0-ppat possesses a minimum overpotential (291 mV), small Tafel slope (91.65 mV dec−1), and high stability up to 83 h. The enhanced catalytic performance could be mainly ascribed to the synergistic effect of NiII equivalent occupancy in pillars and Co/FeIII in layers.

It is still an open debate whether the 1:5H cell boundaries (CBs) or the intersections of 1:3R platelets and 1:5H CBs are the strong pining sites for the cellular nanostructured 2:17-type Sm-Co-Fe-Cu-Zr high temperature permanent magnets despite that they have been widely applied in advanced industries since 1970s. Herein, through tuning the volume fraction of Zr-enriched 1:3R platelets by varying the second-step aging time, the pinning behavior in a model magnet Sm25Co44.9Fe21.5Cu5.6Zr3.0 (wt%) was investigated. The results show that the volume fraction of 1:3R platelets can be effectively enlarged without changing the cell size (i.e. the volume fraction of CBs) by extending the aging time at 400 °C. Microscopic TEM characterizations combined with macroscopic magnetic measurements reveals that the locally thickened 1:3R platelets after long-term second-step aging reduce the effective pinning area by interrupting the magnetic domain walls at CBs, weakening the average pinning strength and the coercivity of the magnet. Consequently, our work supports that the 1:5H CBs act as the dominating pinning sites instead of the intersections of 1:3R platelets and 1:5H CBs, which may provide an important insight towards understanding the hard magnetism of pinning-controlled permanent magnets.

Vibrational microscopy methods based on Raman scattering or infrared absorption provide a label-free approach for chemical-contrast imaging, but employ point-by-point scanning and impose a compromise between the imaging speed and field-of-view (FOV). Optothermal microscopy has been proposed as a promising imaging modality to avoid this compromise, although at restrictively small FOVs capable of imaging only few cells. Here, we present wide-field optothermal mid-infrared microscopy (WOMiM) for wide-field chemical-contrast imaging based on snapshot pump-probe detection of optothermal signal, using a custom-made condenser-free phase contrast microscopy to capture the phase change of samples after mid-infrared irradiation. We achieved chemical contrast for FOVs up to 180 μm in diameter, yielding 10-fold larger imaging areas than the state-of-the-art, at imaging speeds of 1 ms/frame. The maximum possible imaging speed of WOMiM was determined by the relaxation time of optothermal heat, measured to be 32.8 μs in water, corresponding to a frame rate of μ30 kHz. This proof-of-concept demonstrates that vibrational imaging can be achieved at an unprecedented imaging speed and large FOV with the potential to significantly facilitate label-free imaging of cellular dynamics.

Five new triterpenoids named as euphatexols C - G (1-5) were isolated from the latex of Euphorbia resinifera. Their chemical structures were determined by extensive spectroscopic analysis, including IR, HRMS, 1 D and 2 D NMR data. Compounds 1-5 showed moderate anti-inflammatory activity with IC50 values of 22.30, 48.04, 21.89, 38.15 and 41.15 μM, respectively.

To recommend relevant merchandises for seasonal retail events, we rely on item retrieval from marketplace inventory. With feedback to expand query scope, we discuss keyword expansion candidate selection using word embedding similarity, and an enhanced tf-idf formula for expanded words in search ranking., The work is oral presented on the SIGIR Symposium on IR in Practice (SIRIP) 2018

Compounds 1-3, the rare examples of 9,11-seco euphane or lanostane triterpenoids featuring an enol-hemiacetal functionality, were isolated from Euphorbia stracheyi. Their structures were elucidated by a combination of spectroscopic, computational, chemical, and single-crystal X-ray diffraction means, which enables the structure of previously published euphorol J to be revised as 1. 1-3 showed significant cytotoxicities on the breast cancer cell line MDA-MB-468 with IC50 values in the range of 2.9-3.9 μM.

Ti2Nb10O29 (TNO) is a suitable electrode for high-performance lithium-ion batteries and capacitors because of its large lithium storage capacity and high Li+ diffusivity. Currently, the rate or power capability of TNO-based systems is limited by the poor electronic conductivity of the material. Here we report our findings in design, synthesis, and characterization of a hierarchical N-rich carbon conductive layer wrapped TNO structure (TNO@NC) using a novel polypyrrole-chemical vapor deposition (PPy-CVD) process. It was found that carbon coating with PPy–carbon partially reduces Ti and Nb cations, forms TiN, and creates oxygen vacancies in the TNO@NC structure that further increase overall electronic and ionic conductivity. Various defect models and density functional theory (DFT) calculations are used to show how oxygen vacancies influence the electronic structure and Li-ion diffusion energy of the TNO@NC composite. The optimized TNO@NC sample shows notable rate capability in half-cells with a reversible capacity of 300 mAh g−1 at 1 C rate and maintains 211 mAh g−1 at a rate of 100 C, which is superior to that of most MxNbyOz materials. Full cell LiNi0.5Mn1.5O4 (LNMO)||TNO@NC lithium-ion batteries (LIB) and active carbon (AC)||TNO@NC hybrid lithium-ion capacitors (LIC) exhibited notable volumetric and gravimetric energy and power densities.

The dynamic characteristics studies of piezoelectric structures usually focus on the single vibration modes such as the longitudinal or the flexural mode, and the losses that cause heat generation and energy waste are generally neglected, which leads to discrepancies compared with experiments. In the present paper, a beam-type piezoelectric structure with four kinds of losses under coupled longitudinal-flexural vibration mode is investigated. In this approach, first, impedance matrix of the structure is obtained based on the motion equation and the electrical-mechanical boundary conditions. Secondly, admittance curves of this piezoelectric structure under different boundary conditions are simulated by the equivalent circuit methods that contain four losses—piezoelectric and dielectric losses, as well as two elastic losses. The simulation results by equivalent circuit methods has good agreement with COMSOL results, which demonstrate the effectiveness of the proposed method.

A suitable protocol for the photocatalytic decarboxylation of carboxylic acids was developed with metal-free ceramic boron carbon nitrides (BCN). With visible light irradiation, BCN oxidize carboxy...

The production and emission of short-chain perfluoroalkyl acids (PFAAs) has increased over the years to replace long-chain PFAAs, leading to frequent detection in the environment and raising global concerns about the potential impacts on human health. In this study, the specific urine levels of 10 PFAAs were obtained from 189 children (age 8-12 years) from two primary schools located in urban and suburban areas of Shanghai in 2019, and the contributions of dietary factors were investigated. Perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), and perfluorobutane sulfonate (PFBS) were detected in 100%, 99.5%, and 87.3% of the samples, with median concentrations of 20.20 ng/L, 46.50 ng/L, and 20.95 ng/L, respectively. The most abundant PFAA was perfluorooctanoic acid (PFOA), with a median concentration of 78.90 ng/L. The concentration of ∑PFAAs ranged from 61.10 to 4108.93 ng/L, with a median concentration of 253.12 ng/L. Children aged 8-9 years had higher median levels of PFBS, perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) than children aged 10-12 years. Obese/overweight children had lower levels of PFHpA, PFBS, and PFOS. The intake of red meats, tubers, sugared beverages, fish and seafood, and eggs contributed to higher concentrations of PFAAs, while frequent intake of poultry and soy milk was associated with lower PFAA concentrations.

Based on the potential flow theory, a fully nonlinear numerical procedure is developed with boundary element method to analyze the interaction between a fixed semi-submersible platform and incident waves in open water. The incident wave is separated from the scattered wave under fully nonlinear boundary conditions. The mixed Euler-Lagrangian method is used to capture the position of the disturbed wave surface in local coordinate systems. The wave forces exerted on an inverted conical frustum are used to ensure the accuracy of the present method and good agreements with published results are obtained. The hydrodynamic characteristics of the semi-submersible platform interacting with regular waves are analyzed. Pressure distribution with time and space, tension and compression of the platform under wave action are investigated. 3D behaviors of wave run-ups are predicted. Strong nonlinear phenomena such as wave upwelling and wave interference are observed and analyzed.

A metal-free protocol is established for the decarboxylative N–H or C(sp2)–H functionalization of acids via metal-free boron carbon nitride (BCN) photocatalysis, delivering the desired products under ambient conditions. This methodology is applicable to the late-stage modification of pharmaceutical molecules and gram-scale experiments as well as in the recovery and reuse of the photocatalysts without the loss of reactivity. The developed photochemical reaction system fulfills the requirements of green and sustainable chemistry.

Identifying the defects process in concurrent recrystallization and precipitation during aging a supersaturated solid solution is essential for understanding their interaction mechanisms and for manipulating the microstructure, but was rarely done at the atomic scale. Herein, the concurrent recrystallization and precipitation in the supersaturated hexagonal Sm(Co, Fe, Cu, Zr)7.5 alloys were studied through detailed transmission electron microscopy investigations, where the recrystallization, growth of recrystallized subgrains (cells) and precipitates stem from the gradual formation and dissociation of defects, including basal stacking faults (SFs), vacancies and excess interstitial atoms. The diffusion-controlled glides of -type partial dislocations associated with the SFs not only transform the matrix from the mixture of hexagonal Sm(Co, Fe, Cu, Zr)7 (1:7H) and Sm2(Co, Fe, Cu, Zr)17 (2:17H) to Sm-depleted rhombohedral Sm2(Co, Fe, Cu, Zr)17 (2:17R) cells but also provide continuous diffusion channels to reduce the point defects to form the Sm-enriched hexagonal Sm(Co, Fe, Cu, Zr)5 (1:5H) cell boundary precipitates and Zr-enriched rhombohedral (Sm, Zr)(Co, Fe, Cu)3 (1:3R) platelets. It indicates a diffusion-controlled displacive phase transformation mechanism, characterized by the composition-dependent 2:17R’ intermediate phase due to incomplete basal slip and incomplete solute partitioning. The growth velocities of both recrystallized cells and precipitates are closely related to the defects density, being faster due to the high defects density at early stage, and being slower due to the reduced defects density at later stage. A basal slip model is proposed to explain the formation and dissociation of defects along with the stacking period change and the simultaneous formation of continuous atomic diffusion channels. These new findings may yield a deep understanding of the interaction between recrystallization and precipitation.

In this work, the effects of arc ablation on the surface of epoxy (EP) in EP/SF6 composite insulation are analyzed. Based on the results, the characteristics of streamers on the surface of EP is captured by a photomultiplier array and the failure mechanism of the EP is studied. The results show that the arc heat flow applied to the EP/SF6 interface can lead to the decomposition of EP molecular chains and degradation of the SF6. The pyrolysis products re-couple to generate complex carbides and pyrolysis gases, resulting in severe irregular carbonization on the EP surface and the increase in surface conductivity. When an external electric field is applied, a large quantity of photons will accumulate in the carbonization region on the EP surface and this gives rise to the surface streamer and thereby greatly decreases the surface electrical strength of EP/SF6 composite insulation.

Purpose Electromagnetic noise of permanent magnet synchronous motor (PMSM) seriously affects the sound quality of electric vehicles (EVs). This paper aims to present a comprehensive process for the electromagnetic noise analysis and optimization of a water-cooled PMSM. Design/methodology/approach First, the noises of an eight-pole 48-slot PMSM in at speeds up to 10,000 rpm are measured. Furthermore, an electromagnetic-structural-acoustic model of the PMSM is established for multi-field coupling simulations of electromagnetic noises. Finally, the electromagnetic noise of the PMSM is optimized by using the multi-objective genetic algorithm, where a multi-objective function related to the slot width of PMSM stator is defined for radial electromagnetic force (REF) optimization. Findings The experimental results show that main electromagnetic noises are the 8n-order (n = 1, 2, 3, …) and 12-order noises. The simulated results show that the REFs are mainly generated by the 8n-order (n = 1, 2, 3, 4, 5, 6) vibrations, especially those of the 8th, 16th, 24th and 32th orders. The 12-order noise is a mechanical noise, which might be caused by the bearings and other structures of the PMSM. Comparing the simulated results before and after optimization, both the REFs and electromagnetic noises are effectively reduced, which suggests that an appropriate design of stator slot is important for reducing electromagnetic noise of the PMSM. Originality/value In view of applications, the methods proposed in this paper can be applied to other types of PMSM for generation mechanism analysis of electromagnetic noise, optimal design of PMSM and thereby noise improvement of EVs.

Antibiotic resistance is a great concern, which leads to global public health risks and ecological and environmental risks. The presence of antibiotic-resistant genes and antibiotic-resistant bacteria in the environment exacerbates the risk of spreading antibiotic resistance. Among them, horizontal gene transfer is an important mode in the spread of antibiotic resistance genes, and it is one of the reasons that the antibiotic resistance pollution has become increasingly serious. At the same time, free antibiotic resistance genes and resistance gene host bacterial also exist in the natural environment. They can not only affect horizontal gene transfer, but can also migrate and aggregate among environmental media in many ways and then continue to affect the proliferate and transfer of antibiotic resistance genes. All this shows the seriousness of antibiotic resistance pollution. Therefore, in this review, we reveal the sensitive factors affecting the distribution and spread of antibiotic resistance through three aspects: the influencing factors of horizontal gene transfer, the host bacteria of resistance genes and the migration of antibiotic resistance between environmental media. This review reveals the huge role of environmental migration in the spread of antibiotic resistance, and the environmental behavior of antibiotic resistance deserves wider attention. Meanwhile, extracellular antibiotic resistance genes and intracellular antibiotic resistance genes play different roles, so they should be studied separately.

The synthesis of branched-chain alkyl polyglucosides (APG) from 2-butyl-1-octanol, a Guerbet alcohol, in an acid/phase transfer catalyst (PTC) system was studied. Under optimized conditions the conversion rate of this reaction was 98.4% and the selectivity 16.5:1 (APG to polysaccharide, w/o). The APG was characterized by HPLC, LC/MS and 1HNMR. The surfactant properties showed that the wetting time was 17.9 s, and the emulsification time of a 0.15% aqueous solution with soybean oil was 22 min 44 s and with liquid paraffin 11 min 05 s. The critical micelle concentration (CMC) was 5 · 10−4 mol/L, and the surface tension was 25.87 mN/m with a 1% aqueous solution. It is a low foaming surfactant.

Microstructure, texture and mechanical properties of electrically assisted friction stir welding (EFSW) of Ti6Al4 V alloy were investigated. The base material (BM) and the heat-affected zone (HAZ) ...

Trace Zr addition is essential for achieving desired cellular nanostructure and large coercivity in the pinning-controlled 2:17-type Sm-Co-Fe-Cu-Zr magnets that have served as the strongest high temperature permanent magnets for over 40 years. However, accompanying this is the formation of Zr-rich particles that may deteriorate the hard magnetic properties. Besides the formerly-reported 1:3R Zr-rich platelets, in this work, 1–2 μm sized Zr6(Co, Fe)23 (6:23) particles (Fm 3 ¯ m) and 100–200 nm sized 1:3R Zr-rich particles were also found based on combined structural identifications and element mapping analysis. Around such particles, the desired 1:5H cell wall precipitates that provide the strongest pinning force of magnetic domain wall motions are rare, forming the precipitate-free-zones (PFZs). The 1:5H-PFZs and the soft magnetism of both 6:23 and 1:3R Zr-rich particles act as local weak pinning points, which are unfavorable to retain the large magnetization in strong opposite fields and lead to poor squareness. As observed in a Sm25Co45.9Fe19.5Cu5.6Zr4.0 (wt.%) magnet, the co-existence of such Zr-rich particles and the associated 1:5H-PFZs leads to a pretty low squareness factor of only 52.89 % given the large coercivity of 29.04 kOe. Our findings suggest that careful controlling the Zr content and avoiding its aggregation to form harmful 6:23 and 1:3R Zr-rich particles are essential for achieving high squareness as well as large energy product in the Sm-Co-Fe-Cu-Zr permanent magnets.

An environmentally friendly method for the determination of testosterone and methyltestosterone by acid–base-induced deep eutectic solvents liquid–liquid microextraction (DES-ABLLME) combining with high-performance liquid chromatography was established. The deep eutectic solvent (DES) consisting of menthol:lauric acid:decanoic acid (3:1:1) can act as both hydrogen bond donor and hydrogen bond acceptor. In this approach, ammonia solution (NH3•H2O) is used as an emulsifier to react with DESs in the extraction process to generate salt and form milky white solution, achieving high extraction efficiency. Hydrochloric acid was used as a phase separator to change the emulsification state and promote the separation of extraction agent from water phase. A series of parameters were optimized including the volume of DES and the emulsifying agent, glucose concentration as well as hydrochloric acid volume. The method was linear in the range 0.5–100 μg mL−1 with a correlation coefficient (R) of 0.9999, and the limits of detection were 0.067 and 0.2 μg mL−1 for testosterone and methyltestosterone, respectively. This method was applied to analyze testosterone and methyltestosterone in milk samples, and the recoveries were between 89.2 and 108.2%.

This study assessed the effects of different electric current densities on the calcification and photosynthetic physiology of a massive, colonial stony coral species. Coral survivorship, calcification rate, and photosynthetic parameters (zooxanthellae density and chlorophyll fluorescence) were measured to determine the physiological and photosynthetic performance of Galaxea fascicularis after exposure to different electric current densities. After 60 days of treatment, survival of G. fascicularis was higher at low electric current density (10 mA m−2) than in the control and at high electric current density (100 mA m−2). Electric current did not alter zooxanthellae densities, but did enhance the photosynthetic processes (e.g. maximum electron transport rates (rETRm), and maximum quantum yield (Fv/Fm)) within 45 days. Coral calcification rate increased in response to low electric current density up to 30 days, but the effects of the electric current were not significant after a longer period of treatment. Overall, our results indicated that mineral accretion technology with appropriate electric current density conditions was somewhat helpful in enhancing coral growth, and thus this technique may be used in the restoration and management of massive stony coral reefs.

Two new lathyrane-type diterpenoids, jatropodagins A and B (1 and 2), and five known analogues (3–7), were isolated from the stems of Jatropha podagrica. Their structures and absolute configurations were elucidated by spectroscopic data and calculated ECD analyses. The cytotoxicities of all the lathyrane-type diterpenoids (1–7) were evaluated against two human osteosarcoma cell lines (Saos-2 and MG-63). Compound 1 exhibited significant cytotoxic effects against Saos-2 and MG-63 with IC50 values of 8.08 and 14.64 μM, respectively. The IC50 values for the positive control 5-FU against the Saos-2 and MG-63 cell lines were 19.01 and 25.00 μM, respectively. Morphological features of apoptosis activities were evaluated in 1-treated Saos-2 cells and the results confirmed apoptosis in a dose-dependent manner.

Both SmCo5 and Smn+1Co5n−1-type phases were identified in the Sm25Co42.9Fe23.5Cu5.6Zr3.0 (wt.%) commercial sintered magnet even at the solution-treated state, with the 1:5H cell boundary phase occupying pyramidal planes, the 1:3R (n = 2) thin platelets occupying some basal planes, and the mixture of 1:3R, 2:7R (n = 3) and 5:19R (n = 4) phases distributing at grain boundaries. The mixed Smn + 1Co5n − 1-type phases at grain boundaries act as primary sinks and lead to sparse 1:5H-precipitates surrounding them after isothermal aging. It clearly reveals that the 1:5H cell boundaries are formed at the early decomposition stage and why they are rare at grain boundaries in the aged magnets.

A novel method for analyzing a rotating target by an orthogonal-beam Doppler velocity measurement system on the basis of a single laser diode is presented. Using the method of fast Fourier transform after smoothing filter, we can obtain two groups of Doppler frequency shifts in the spectrum to calculate the velocity of a rotating target. A theoretical analysis and an experimental setup have been implemented. Experimental results show that a relative error of this velocity-measuring system is less than 0.5%.

In this paper, a novel phase demodulation method for multiple self-mixing interferometry (MSMI) is proposed, which can improve the resolution and accuracy of vibration measurement in laser self-mixing interferometry (SMI). The sinusoidal phase modulation of the beam is obtained by an electro-optic modulator (EOM), and phase demodulation is performed by a lock-in amplifier analysis method. The phase equation of MSMI was derived and the theory of the lock-in amplification technique was analyzed in detail. The validity of the proposed method is confirmed by means of simulated signals and then demonstrated by several experimental measurements. The experimental results indicated a good correspondence between theory and experiment.

Three new highly oxygenated lanostane triterpenoids, applanaic acids A–C (1–3), were isolated from the fruiting bodies of the basidiomycete Ganoderma applanatum. Among them, applanaic acid B (2) po...

Metal-organic frameworks (MOFs) based membranes with superior mechanical properties are of particular interest in purification, separation, and catalysis. Nevertheless, their fabrication still remains a grand challenge. Here, fungus hyphae (Mucor) were used as a robust scaffold to load the MOFs and induced the formation of porous and flexible membranes. ZIF-8 was used as a representative of MOFs. The ZIF-8@Mucor membrane was formed by the in-situ growth of ZIF-8 on hyphae and then a vacuum filtration of the ZIF-8/hyphae composite. ZIF-8 was effectively dispersed on the ZIF-8@Mucor membrane, and the shear modulus of ZIF-8@Mucor-3 was 864 MPa by calculation. The ZIF-8@Mucor membrane exhibited promising properties for adsorption application to remove the highly toxic Pb2+. The adsorption capacity of this membrane was as high as 1443.29 mg/g. Results from dynamic adsorption indicated that the penetration concentration of Pb2+ ions was less than 5% of the original level before 80 min whereas after 160 min, penetration concentration of Pb2+ ions was more than 90%. This study would open a new way of how to synthesize composite MOFs/bacterial membranes for energy and environment purposes.

As the hydrocarbon generation and storage mechanisms of high quality shales of Upper Ordovician Wufeng Formation- Lower Silurian Longmaxi Formation remain unclear, based on geological conditions and experimental modelling of shale gas formation, the shale gas generation and accumulation mechanisms as well as their coupling relationships of deep-water shelf shales in Wufeng–Longmaxi Formation of Sichuan Basin were analyzed from petrology, mineralogy, and geochemistry. The high quality shales of Wufeng–Longmaxi Formation in Sichuan Basin are characterized by high thermal evolution, high hydrocarbon generation intensity, good material base, and good roof and floor conditions; the high quality deep-water shelf shale not only has high biogenic silicon content and organic carbon content, but also high porosity coupling. It is concluded that: (1) The shales had good preservation conditions and high retainment of crude oil in the early times, and the shale gas was mainly from cracking of crude oil. (2) The biogenic silicon (opal A) turned into crystal quartz in early times of burial diagenesis, lots of micro-size intergranular pores were produced in the same time; moreover, the biogenic silicon frame had high resistance to compaction, thus it provided the conditions not only for oil charge in the early stage, but also for formation and preservation of nanometer cellular-like pores, and was the key factor enabling the preservation of organic pores. (3) The high quality shale of Wufeng–Longmaxi Formation had high brittleness, strong homogeneity, siliceous intergranular micro-pores and nanometer organic pores, which were conducive to the formation of complicated fissure network connecting the siliceous intergranular nano-pores, and thus high and stable production of shale gas. Key words: hydrocarbon generation and storage mechanism, Upper Ordovician Wufeng Formation, Lower Silurian Longmaxi Formation, deep-water shelf, siliceous shale, Sichuan Basin, pore preservation

Dissolution rates of porous crystalline materials reflect the superposition of transport and surface control, mainly via the parameters saturation of the ambient fluid and distribution of surface energy. As a result, reacting surfaces evolve over time showing a heterogeneous distribution of surface rates. The spatiotemporal heterogeneity of surface reaction rates is analyzed using the rate map and rate spectra concept. Here, we quantify the dissolution rate variability covering the nm- to mm-scale of dissolving single-crystal and polycrystalline calcite samples, using a combined approach of X-ray micro-computed tomography (µ-CT) and vertical scanning interferometry (VSI). The dissolution experiments cover reaction periods from 15 minutes up to 54 days. The observed rate ranges are remarkably consistent over the entire reaction period but include a variability of about two orders of magnitude (10-9 - 3 * 10-7 mol m-2 s-1). The rate map data underscore the concurrent and superimposing impact of surface- vs. fluid flow controlled rate portions. The impact of fluid flow on reactivity at the mm-scale in the transport-controlled system is confirmed by 2-D reactive transport modeling. The sub-mm spatial heterogeneity of low vs. high reactivity surface portions of polycrystalline calcite is clearly below the mean crystal size. This suggests the dominant impact of highly reactive surface portions irrespective of the orientation of larger crystals on the overall surface reactivity. Correspondingly, the overall range of intrinsic reactivity heterogeneity as observed using singly crystal material is not further expanded for polycrystalline material. As a general conclusion, numerical reactive transport concepts would benefit from the implementation of a reactivity term resembling the experimentally observed existence of multiple rate components.

The friction stir overlap welding on variable polarity plasma arc (FSOW-VPPA) weld was first proposed for a complete girth weld in 2219 aluminium alloy. The mechanical properties, microstructures, and metallurgical processes of FSOW-VPPA in comparison to single-FSW and VPPA welded joints were studied in this paper. The FSOW-VPPA welded joint was characterized by the modified nugget zone (NZ), thermo-mechanically affected weld zone (WZ), heat affected fusion zone (FZ), and double heat affected zone (HAZ). The modified NZ was characterized by “onion-rings” without the porosity that appeared in the VPPA weld. The grains in the thermo-mechanically affected WZ were finer than that of the VPPA weld. In the second thermal cycle, the angle of the direction of crystal growth from the horizontal decreased from 38 degrees in the VPPA weld to 22 degrees. In contrast with the single-FSW weld, there was no serious deformation on the advancing side (AS). In general, the second thermal cycle did not degrade the quality of the weld. The elimination of pores and grain refinement improved both the tensile strength and elongation of the FSOW-VPPA weld compared to the VPPA and single-FSW welds. The tensile strength increased to 84.0% compared to 79.8% for the VPPA weld. In addition, the metallurgical processes were analysed and compared. Keywords: VPPA, FSW, Overlap weld, Mechanical properties, Metallurgical processes

In this paper, 4 × 4/8 × 8/10 × 10 multiple input multiple output (MIMO) antenna systems composed of co-located self-neutralized antenna pairs are proposed to operate at 4.8-5.0 GHz (part of N77 band) for the fifth-generation (5G) communication applications. The proposed antenna pairs consist of a loop antenna and a monopole antenna, co-locating together with a compact size of 6.7 × 15.5 ×3.08 mm3. Meanwhile, the co-located design can miniaturize 50% of the antenna size, which is quite significant for practical mobile applications with limited space environment. In addition, the adoption of the self-neutralization technique between the co-located loop antenna and the monopole antenna contributes to a satisfactory isolation with better than 25/20/16.5 dB for the 4 × 4/8 × 8/10 × 10 MIMO systems respectively. Analysis of the isolation improvement is also discussed in this study. Moreover, the antenna pairs are able to generate complementary radiation patterns, enabling the envelope correlation coefficients (ECC) between the antennas to be less than 0.1. Also, efficiencies of the MIMO antenna system achieve up to 60% as there is no external decoupling structure deteriorating the radiation performance of the proposed antenna pairs. Finally, a 4 × 4 MIMO antenna system prototype is fabricated and measured to verify its prospect for 5G MIMO applications.

Nitrogen and oxygen dual-doped amorphous carbon network (NOCN) facilely prepared via self-assembly method in this study as potassium ion battery’ anode for ultra-long and superior-rate capability. The as-synthesized NOCN exhibits an excellent reversible capacity of 464.9 mAh g-1 at 0.05 A g-1, outstanding performance of 175 mAh g-1 at a high current density of 5.0 A g-1, and ultra-long cycling performance with capacity decay less than 0.008% per cycle. The superior performance can be attributed to the unique ultra-stable network structure together with N and O co-doped. Supported by detailed fundamental analysis, the higher K-ion storage process in NOCN is contributed by the pseudocapacitive mechanism. The simple synthesis route as well as the hopeful electrochemical property shed a new insight into the quest for carbon-based K-storage anode materials with high energy and long-cycling life.

The natural-product-based low-molecular-weight supramolecular hydrogels (LMWSHs) induced by heating are rarely reported. In this work, a simple salt of oleanolic acid (OA) and choline ([choline][OA]) was used as the natural product hydrogelator (NPHG) to form LMWSHs. Unlike common sol-gel transitions, the OA-based LMWSH displayed a unique property with which the system could undergo a phase transition from the sol state to the gel state upon heating. Moreover, the phase separation was observed in sol and gel states when the temperature was elevated with nonreversible transparent-turbid transitions. LMWSHs showed good stability and injectability and the potential to be a drug delivery vehicle for sustained release of drugs. In this regard, this work provided a facile approach to designing an OA-based NPHG for preparing heat-induced LMWSHs.

For the high-order harmonic generation (HHG) from solids, the dephasing process induced by many-body interactions has been discussed extensively in the studies of using the semiconductor Bloch equations (SBEs). However, the role of dephasing in solid HHG is always ignored in the simulations of using a time-dependent Schr\"odinger equation under the independent electron approximation. To solve this problem, we introduce the imaginary potential to phenomenologically depict the dephasing process in the solid HHG. Compared with the results of experiment and SBEs, the validity of this approach has been verified by the laser intensity- and wavelength-dependent HHG spectra. Diffusion of the quantum wave packet controls the time-frequency characteristic in solid HHG. To obtain semiclassical trajectories whose predictions are consistent with the quantum simulations, we propose an open-trajectory model by relaxing the zero displacement condition in the tunneling and recollision steps. In addition, the quantum decoherence adjusts the chirp of the emission time profile via modulating the coherent overlap between recombined wave packets, which further paves a way to generate an attosecond pulse from solids and probe the dephasing time via the high-harmonic spectroscopy.

The present study aims to investigate the structure of covalent conjugates of bovine β-lactoglobulin (BLG) and flavonoids (luteolin, myricetin, and hyperoside), and their effect on the allergenicity and human intestinal microbiota. Covalent modification of amino acids in BLG by flavonoids was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and o-phthaldialdehyde assay. The secondary and conformational structures of BLG were changed by the covalent modification, which were determined by the circular dichroism, Fourier transform infrared spectroscopy, fluorescence spectroscopy, and UV spectroscopy. The enzyme-linked immunosorbent assay (ELISA) and cell experiments indicated that BLG covalent conjugates could reduce IgE/IgG binding capacities and suppress the allergy reactivity of RBL-2H3 cells, suggesting that the covalent modification modulated the balance of T cells. Meanwhile, covalent modification of BLG with these flavonoids can alter the diversity of human intestinal microbiota and the community abundance at phylum, family, and genus levels. The results revealed that covalent modification of BLG with flavonoids alters human intestinal microbiota, might result in the reduction of allergenicity, which could provide information for confirming the relationship between food allergy and the intestinal microbial ecosystem.

This study aimed to evaluate the antiglycation ability of Elaeagnus angustifolia flower extract and to elucidate the mechanism with its major compound. The results indicated that E. angustifolia flower extract and its major compound tiliroside (24.2 mg/g of extract) exhibited excellent antiglycation ability with inhibition rates of 92.1 and 78.9% at 37.5 μg/mL, which are much higher than that of aminoguanidine (55.3% at 37.5 μg/mL). The stable tiliroside-ovalbumin (OVA) complexes were formed through a spontaneous exothermic progress in an equimolar manner, and hydrophobic interaction, hydrogen bond, and van der Waals forces were the major driving forces. Tiliroside could significantly ameliorate the conformation changes of OVA induced by the glycation reaction, quench its fluorescence by a static mechanism, and change the microenvironment adjacent to tryptophan and tyrosine. Molecular docking revealed that tiliroside inserted into the OVA hydrophobic pocket resulted in the formation of five hydrogen bonds. Orbitrap tandem mass spectrometry showed that tiliroside significantly suppressed the glycation of OVA, and the number of glycation sites was reduced from 9 to 5 after tiliroside was added. The above results indicated that E. angustifolia flowers and tiliroside have a good antiglycation effect and can be used as food additives to suppress the undesired glycation reaction during food processing.

Capacitive deionization (CDI) is increasingly being considered as an effective solution for treating heavy-metal contaminated water. Surface modification of electrode materials with metal oxides is the key to yield high specific capacitance of transition metal oxides for enhancing the efficiency of CDI processes. In this study, we proposed a simple and effective strategy to produce a new, well-ordered Fe2O3@C composite for Pb2+ removal via CDI technology. Through controlling hydrofluoric acid-inducing solvothermal carbonization, Fe2O3 dots were highly dispersed in carbonized substrates without using traditional high-temperature calcination. The products possessed regular octahedral morphology with a uniform distribution of α-Fe2O3 in nearly quantum scale (∼20 nm) throughout the carbon matrixes. Compared with other similar materials, the well-dispersed Fe2O3 in carbon matrixes significantly increased the surface areas (∼1832 m2 g−1) and specific capacitance (115.6 F g−1) of Fe2O3@C composites. Using the composites as electrodes, the Pb2+ adsorption capacity reached 830.17 mg g−1, which is 28% higher than reported materials. Furthermore, the composites electrode possess a high regeneration efficiency, after 10 cycles, 90.3% of the initial performance is still retained. Our study demonstrated great potential of the novel Fe2O3@C composites for the removal of heavy metal ions using CDI processes.

A Gram-stain-negative, rod-shaped and aerobic bacterium, designated CL12T, was isolated from roots of Glycine max (Linn. Merr.) collected from an experimental field in the campus of South China Agricultural University, PR China (22°58′46″S, 110°51′10″E). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CL12T belongs to the genus Rhizobium, closely related to Rhizobium wuzhouense W44T (99.3%), followed by Rhizobium rosettiformans W3T (98.0%) and Rhizobium ipomoeae Shin9-1T (97.9%). The results of analysis of sequences of four housekeeping genes (recA, atpD, rpoB and glnA) also revealed strain CL12T to be closely related to R. wuzhouense W44T with the similarities 91.0%, 95.0%, 94.2% and 90.5%, respectively. The major fatty acid of strain CL12T was Summed Feature 8 (C18:1ω7c and/or C18:1ω6c). Strain CL12T had not the nodulation genes (nodC and nodA) and nitrogenase reductase gene (nifH), and could not cause formation of nodule on soybean. The draft genome size of strain CL12T was 4.84 Mbp with a genomic DNA G + C content of 61.1 mol%. The digital DNA–DNA hybridization (dDDH) and average nucleotide identity (ANI) of strain CL12T and R. wuzhouense W44T were 27.4% and 84.7%, respectively. Based on genomic, phenotypic and phylogenetic analysis, strain CL12T is suggested to represent a new species of the genus Rhizobium, for which the name Rhizobium glycinendophyticum sp. nov. is proposed. The type strain is CL12T (=GDMCC 1.1597T = KACC 21281T).

A facile, green and economical method for the high-efficiency utilization and functionalization of bamboo fiber could significantly improve the development of biomass industries. Here, we demonstrated a deep eutectic solvent, which formed from choline chloride (ChCl) and lactic acid (LC), as pretreating agent to delignify moso bamboo (Phyllostachys pubescens) and produce nanocellulose. The results showed that most of the lignin was efficiently removed (94.39%) and 91% of the cellulose was recovered after the moso bamboo was pretreated with ChCl–LC at 120 °C for 3 h with a solid-to-liquid ratio of 1:25. Furthermore, nanofibers with widths of 20–80 nm were successfully prepared from pretreated fibers after a simple mechanical process. SEM and AFM images showed that they have excellent aspect ratio. In addition, the obtained nanofibers could be used to fabricate strong films which feature a high tensile strength ranged from 163 to 213 MPa.

Lithium-sulfur (Li–S) batteries are considered to be a promising energy storage owing to high energy density and low cost. However, the S cathodes are still suffering from poor cycle life and low Coulombic efficiency due to ‘shuttle effect’ of lithium polysulfide. Herein, we report a novel and effective strategy to fabricate a free-standing Li–S battery cathode with enriched anchoring and catalytic N-sites host. Benefiting from synergistic effects of multifunctional porous carbon nanofiber host (g-C3N4@PCNF), the g-C3N4@PCNF/S cathode achieves good flexibility and excellent cycling retention, such as stable long cycle performance with a capacity decay of only 0.056% per cycle over 500 cycles at 1.0 A g−1. The excellent performance of g-C3N4@PCNF/S cathode can be mainly attributed to: (i) the interconnected network and internal porous structure of PCNF offering free space for S-loading and volume change during charge/discharge; (ii) the 3D g-C3N4@PCNF host providing an efficient electron/Li+ transport highway for fast interfacial reaction kinetics; (iii) the catalytic effect of g-C3N4 promoting rapid redox conversion of S species and retarding polysulfide shuttling. This effective strategy has demonstrated great potential as good candidates for commercial flexible and durable Li–S batteries.

Implantable pressure biosensors show great potential for assessment and diagnostics of pressure-related diseases. Here, we present a structural design strategy to fabricate core/shell polyvinylidene difluoride (PVDF)/hydroxylamine hydrochloride (HHE) organic piezoelectric nanofibers (OPNs) with well-controlled and self-orientated nanocrystals in the spatial uniaxial orientation (SUO) of β-phase-rich fibers, which significantly enhance piezoelectric performance, fatigue resistance, stability, and biocompatibility. Then PVDF/HHE OPNs soft sensors are developed and used to monitor subtle pressure changes in vivo. Upon implanting into pig, PVDF/HHE OPNs sensors demonstrate their ultrahigh detecting sensitivity and accuracy to capture micropressure changes at the outside of cardiovascular walls, and output piezoelectric signals can real-time and synchronously reflect and distinguish changes of cardiovascular elasticity and occurrence of atrioventricular heart-block and formation of thrombus. Such biological information can provide a diagnostic basis for early assessment and diagnosis of thrombosis and atherosclerosis, especially for postoperative recrudescence of thrombus deep within the human body.

Modified BCN (m-BCN) nanosheets are synthesized by a KCl-assisted molten salt strategy with boric acid, glucose, and urea as precursors. The as-obtained m-BCN nanosheets show decreased thickness, e...

The mechanism of the microstructure refinement of metals and alloys (5052 and 6061) by arc oscillating was studied and discussed via the grain size of regular welds and those welded at different os...

Catalytic supercritical water oxidation (CSCWO) has sprung up as a promising technique to eliminate refractory aromatic compounds, which are difficult to be removed by conventional wastewater treatment processes. Decompositions and degradation mechanisms of 18 aromatic compounds, including benzene, phenol, bisphenol A (BPA) etc., were investigated using CSCWO in this study. It was found that TOC removal efficiencies of the aromatic compounds were significantly enhanced, when CSCWO temperatures raised from 325 to 525 °C and reaction time prolonged from 0.5 to 6 min, with the addition of Cu(NO3)2. The correlationships among TOC degradation rates (kTOC), temperature at TOC removal rate of 90% (T90) and 19 molecular descriptors were studied. The results indicated that BOn and q(H)x could greatly impact the degradation behaviors. Fukui indices based density functional theory (DFT) method was applied to reveal the conceivable degradation pathway of BPA during CSCWO process.

Background: Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals that are widely used in industrial and consumer products. A growing body of literature suggests that exposure to these chemicals are associated with adverse reproductive outcomes in women. However, the sources of PFAS exposure are often poorly characterized in women of child-bearing age. Objectives: To examine the association of plasma PFAS concentrations with dietary intake and drinking water sources in reproductive aged women in Shanghai, one of the high PFAS polluted regions in China. Methods: Concentrations of ten PFAS in plasma samples were measured in 933 women. Information on dietary intake and type of drinking water was collected by questionnaire. We used multivariable linear regression models to assess the association of PFAS concentrations with dietary intake and drinking water. Results: After controlling for potential confounders, a higher frequency of intake of aquatic products (freshwater fish, marine fish, shellfish, shrimp and crab) was positively and significantly associated with concentrations of PFOS, PFOA, PFNA, PFDA, PFUA and PFDoA in 900 reproductive aged women. Intake of freshwater fish showed the strongest association with PFAS. Compared with the lowest intake group of freshwater fish, the intermediate intake group had 8–32% increase in the concentrations of these pollutants; and the highest group had 11–57% increase. Conversely, intake of soy products was associated with lower levels of PFDA, PFUA, PFNA, PFOS, and PFDoA. In addition, compared with women drinking tap water, drinking bottled water was associated with significantly decreases in PFHpA, PFDA, PFOA, PFUA and PFBS blood levels by 9–13% in 905 reproductive aged women. Conclusions: Intake of freshwater fish, marine fish, shrimp and crab was positively associated with plasma PFAS concentrations, while intake of soy products and bottled water was associated with lower PFAS concentrations in the Chinese women of reproductive age. Keywords: Perfluoroalkyl and polyfluoroalkyl substances (PFAS), Diet, Drinking water, China

Background Several epidemiological studies suggest that prenatal exposure to BPA may interfere with the neurodevelopment of pre-school and school-age children. However, a limited number of studies are available for effects during children at a younger age, especially in China. Methods Based on Laizhou Wan Birth Cohort (LWBC), BPA concentrations were measured in urine among 506 pregnant women during their hospital admission for delivery and neurodevelopment of their children was assessed using the Gesell Development Schedules at 12 months (n = 368) and 24 months (n = 296). Linear regression and generalized linear models were used to analyze the association between prenatal BPA exposure and the children's developmental quotient scores (DQs). Results The median of maternal BPA concentration was 0.48 μg/L or 1.05 μg/g creatinine. Maternal BPA concentrations were adversely associated with children DQs at 12 months of age, with a 10-fold increase in prenatal BPA concentrations correlated to 1.43-point decrease in DQs in the adaptive domain (β = −1.43; 95% CI: −2.30 to −0.56, p = 0.001). When stratified by gender, prenatal BPA concentrations were adversely associated with the adaptive domain DQs among boys (p-trend = 0.012) and girls (p-trend = 0.028) and the social domain DQs (p-trend = 0.019) only among girls. At 24 months of age, the significant adverse association was only found in the language domain among girls (β = −1.69; 95% CI: −3.23 to −0.15, p = 0.032). Conclusion Based on a Chinese population, we found potential impacts of prenatal BPA exposure on childhood neurodevelopment at 12 and 24 months of age, especially among girls.

Complementary-Metal–Oxide–Semiconductor (CMOS) camera based visible light communication (VLC) technology has been widely studied due to its high robustness and easy promotion. The data transmission rate is one of the most challenges for the camera based VLC system. In this work, a novel hybrid modulation scheme including Pulse Width Modulation (PWM), Pulse Position Modulation (PPM), and Discrete Pulse Amplitude Modulation (DPAM) is proposed. The PWM and PPM are used to increase the data transmission rate of the system while the DPAM is aimed to achieve the dimming function. Experiments show that the proposed scheme can achieve 10.47kb/s data rate per image frame. The proposed modulation scheme not only greatly improves the data rate, but also realizes the dimming function, which satisfies the requirement of the IEEE 802.15.7 VLC Task Group standard.

Contact tube wear is the bottleneck of industrial application for non-copper-coated solid wire. It is crucial that we understand the wear mechanism of contact tube so that we can decrease contact tube wear. The effects of temperature and heat input on contact tube wear were investigated in this work. The results demonstrated that fatigue peeling was the main wear mechanism of the contact tube at room temperature without supplying a welding current. Adhesive wear, oxidative wear and abrasive wear were the primary wear mechanisms of the contact tube at 450 °C without supplying a welding current. The wear rate of the contact tube during welding was significantly enhanced in comparison with the wear rate at 20 °C and 450 °C. The effect of contact tube temperature on the wear properties of the contact tube was limited. The wear rate of the contact tube was increased with increasing heat input for non-copper-coated solid wire. The wear mechanism of the contact tube was converted from oxidative wear to arc ablation at the heat input of 9114 J/cm.

Since hydrogenation of C=C bond in the cinnamaldehyde is thermodynamically favored, the selective hydrogenation of C=O group is challenging. Developing effective catalysts for this transformation has been hindered by the intrinsic disadvantages of traditional materials for decades. Hereby, we report the synthesis of the low dimensional Co based nanorods (NRs) as the effective platform for C=O groups hydrogenation in the conjugated compounds. The Pt/Co-NRs catalyst is simply fabricated by loading the Pt nano-particles (NPs) on the Co-NRs and the stability of the Co-NRs support is improved by coordination between the Pt NPs and the pyridinic N ring. Resorting to XRD, FT-IR, XPS, HRTEM, DTG-TG characterization methods, the catalytic mechanism for C=O bond hydrogenation has been proposed. The synergistic effects of K+ and OH− enhance the polarization of C=O group, leading to more adsorption of C=O groups on the Co-NRs so as to promote its hydrogenation performance. In the absence of spatial micropores in low dimensional Co based nanorods, the Pt/Co-NRs catalyst is more advantageous for mass transfer. Under optimal conditions, the conversion of cinnamaldehyde is 97.9% with 92.7% selectivity of cinnamyl alcohol within 3 h. In addition, the selectivity of cinnamyl alcohol changes slightly (only 2.4% fluctuations) after five recycle tests.