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Herein, the effects of cocrystals of two nitroamine explosives, namely hexanitrohexaazaisowurtzitane (CL-20) and 1,3,5,7-tetranitro-1,3,5,7-tetrazoctane (HMX), which are denoted as CHC, on the combustion properties, heat release, and safety profiles of polyether solid propellants were systematically analyzed. The peak decomposition temperature of CHC was found to be 244.8 °C, which is lower than those of its component CL-20 and HMX. However, the thermal stability of CHC was similar to that of CL-20, and the thermal decomposition behavior of CHC was significantly different from that of a physical mixture of CL-20 and HMX. In addition, similar to CL-20, CHC was not completely decomposed upon heating, despite the decomposition activation energy of CHC (322.7 kJ·mol−1) being similar to that of HMX (322.4 kJ·mol−1). In contrast, the thermal decomposition behaviors of CHC-based propellants differed from those of solid propellants that were based on physical mixtures of CL-20 and HMX. During thermal decomposition, CHC did not decompose into CL-20 and HMX, and the heat released from the CHC-based propellants was more concentrated than that released from the other propellant mixture examined. Furthermore, the rate of combustion of CHC-based propellants fell between those of the CL-20- and HMX-based propellants at all the tested pressures. The pressure exponents of combustion rates of the examined CHC-based propellants were slightly lower than those of the CL-20- and HMX-based propellants, and the combustion rates and their corresponding pressure exponents decreased with a decrease in the CHC particle size. Moreover, the explosive heat of CHC-based propellant was between those of the CL-20-based and HMX-based propellants, and similar to that of a CL-20/HMX mixture-based propellant. Finally, the safety performance of CHC-based propellant was almost identical to that of the CL-20/HMX mixture.

Two new benzazepine alkaloids (1 and 2) were isolated from the whole plants of Thalictrum wangii. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1 and 2 were tested for their anti-rotavirus activity. The results revealed that compounds 1 and 2 exhibited potent anti-rotavirus activity with TI values of 17.9 and 17.6, respectively.

Intermetallic alloy ZrCo is believed to be a good substitution for uranium to store tritium. Nevertheless, disproportionation reaction often happens during the hydriding and dehydriding processes, and hydrogen storage property of ZrCo is therefore degraded. Alloying elements are often used to substitute Zr or Co in ZrCo to restrain disproportionation reaction. However, many experimental results do not agree with each other, and it lacks overall tendency for all transition metal elements. In this work, systematical ab initio calculations are performed to study more than 20 transition alloying elements to substitute Co and Zr in ZrCoH3 to study the anti-disproportionation effects. It is found that substitution of Co by transition metal elements on anti-disproportionation reaction is unconspicuous, and only Ni can enlarge Zr–H bond length and decrease the volume of 8e site, presenting anti-disproportionation effect, which qualitatively agrees with the previous experiments. In contrast, all transition alloying elements considered except Fe, Co, Ni, Ru, Rh, Pd, Os and Ir replacing Zr can both enlarge the length of Zr–H bond and decrease the volume of 8e site, and thus restrain the disproportionation effects. At last, two-dimensional charge density and density of states are calculated to analyze the underlying mico-mechanisms affecting the effects of transition alloying elements on anti-disproportionation reaction.

The development of effective electrocatalysts for sustainable energy conversion and storage is highly desired, but still a considerable challenge due to the sluggish oxygen evolution reaction (OER). Herein, we report a novel composite of MIL-53(Fe) with Ni3S2 nanosheet arrays supported on Ni foam that ingeniously combines the chemical and structural advantages of the MOFs and metal sulfides to perform as a high-performance synergistic OER electrocatalyst in alkaline solution. The hybrid Ni3S2/MIL-53(Fe) simultaneously realizes high electrical conductivity to facilitate charge transfer and abundant coordinatively unsaturated centres, porosity and high surface area to provide a great number of active sites. Strikingly, synergistic electronic interaction between Ni3S2 and MIL-53(Fe) is generated in the hybrid composite. Collectively, the coupled Ni3S2/MIL-53(Fe) exhibits excellent OER performance in comparison to bare Ni3S2 and MIL-53(Fe), with low potentials of 214 and 251 mV to reach current densities of 10 and 100 mA cm−2, respectively. The Tafel slope is 33.8 mV dec−1, which is also markedly lower than those of Ni3S2, MIL-53(Fe) and most reported Ni-based electrocatalysts. The present work paves a promising avenue to design and fabricate highly active and earth-abundant electrocatalysts toward the OER.

A novel alkynyl neutral polymer-bonding agent (NPBA) was synthesized by a three-step approach. The molecular structure and thermal characteristics of alkynyl NPBA were analyzed. To reveal the influence of alkynyl NPBA on the mechanical properties of glycidyl azide polymer (GAP)-based propellants, two types of GAP propellants with Desmodur N-100 and alkynyl-terminated polyethylene glycol (APE) as curing agents were prepared and mechanical properties of the propellants were fully investigated. Tensile strength and initial modulus of propellants were notably promoted with the increase in alkynyl groups content of alkynyl NPBA with Desmodur N-100 as curing agent. The interfacial adhesion property between GAP binders and CL-20 fillers was greatly improved by alkynyl NPBA, and dewetting phenomenon of propellants during uniaxial tension was markedly attenuated. The wettability of GAP binders and solid fillers was good and the enhancing effect of alkynyl NPBA on tensile strength of GAP propellants was notable. Tensile strength and initial modulus of propellants were notably increased and their maximum elongation was decreased with the increase of alkynyl group content of alkynyl NPBA in propellants when APE was used as a curing agent. In addition, the dynamic mechanical analysis results showed that internal friction resistance of GAP molecular segment motion of GAP propellants was increased and interactions between GAP binder and solid fillers became much stronger with alkynyl NPBA. A notable enhancement effect on tensile strength and initial modulus of GAP propellants was demonstrated with alkynyl NPBA as bonding agent.

Developing low-cost and earth-abundant electrocatalysts with high activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is highly desired but still remains a significant challenge. Herein, hollow cobalt hydroxide/NiCo sulfide hybrid (Co(OH)2/Ni-Co-S) nanotube arrays are synthesized on nickel foam (NF) through a simple hydrothermal method and subsequent sulfurization, which serve as efficient electrocatalysts for overall water splitting. The optimized Co(OH)2/Ni-Co-S-8h electrocatalyst requires overpotentials of 300 mV and 340 mV to reach current densities of 30 and 100 mA cm−2 for the OER in 1.0 M KOH, respectively. In addition, the optimized Co(OH)2/Ni-Co-S-8h electrocatalyst requires overpotentials of 148 mV and 254 mV to reach the current densities of 10 and 100 mA cm−2 for the HER in the same electrolyte, respectively. Furthermore, the electrolyzer used as efficient catalysts for overall water splitting requires cell voltage of 1.62 V to obtain 10 mA cm−2.

Pure W, and W–0.5wt%ZrC (WZC) and W–2.0wt%Zr–0.5wt%ZrC (WZZC) alloys are fabricated using vacuum hot pressure (VHP) method to investigate the effects of trace ZrC or Zr/ZrC on the mechanical properties and microstructure of tungsten. It was found that from W to WZC and to WZZC, the average grain size was refined from 6.2 µm of W to 5.8 μm of WZC and finally to 4.8 um for WZZC and relative density increase continually from 97.0% to 98.0% and to 98.5%. The tensile tests indicated that ZrC or ZrC/Zr significantly increases the strength and ductility/plasticity. The comparison of VHPed and spark plasma sintered (SPSed) specimen are made. The microstructure analysis indicate that the W–Zr–O and/or Zr–C–O particles resulting from the reaction of Zr or ZrC with free O pin grain boundaries (GBs) of tungsten and inhibits the migration of GBs, and then refining the grain size. The synergistic effects of the decrease of free O impurity and nano-sized ZrC dispersion strengthening strengthen GBs and improve the mechanical properties. Keywords: Tungsten, Trace Zr/ZrC, Mechanical property, Microstructure

Bulk W-0.5 wt% ZrC (WZC) plates were fabricated using tungsten powders with different powder grain sizes of 0.2 μm, 0.5 μm and 2.8 μm, respectively. The different grain sizes resulted in completely different micro-structures and mechanical properties of as-rolled WZC plates. For the tungsten plate prepared from the initial powder with grain size of 0.5 μm (0.5WZC), more excellent mechanical properties were achieved than those of plates made of powders with grain sizes of 0.2 μm (0.2WZC) and 2.8 μm (2.8WZC). In the as-rolled 0.5WZC, the ductile-brittle transition temperature is as low as 150 °C and ultimate tensile strength is as high as 932 MPa at 150 °C, respectively. Moreover, the 0.5WZC plate has the most outstanding high-temperature stability with a recrystallization temperature of 1500 °C. Micro-structure analysis indicates that the second-phase particles are uniformly distributed in the 0.5WZC, but serious particle aggregation occur in the 2.8WZC. The possible micro-mechanisms have been proposed.

A dual dynamic chamber system combined with incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) was first developed to measure nitrous acid (HONO) emission fluxes from agricultural fields in the North China Plain. The concentrations of HONO were measured with two IBBCEAS instruments in the sample and blank chambers, respectively. To ensure the accuracy and reliability of flux measurement, before the dynamic chamber system was deployed in an agricultural field, the correlation and accuracy of the two IBBCEAS instruments were tested, and the mixing uniformity of the gas in the chamber was verified. Within a week after fertilization, the observed HONO flux exhibited a pronounced diurnal variation profile with a maximum of 20.25 ng N m−2 s−1 at noontime and a minimum of −0.86 ng N m−2 s−1 in the early morning, one order of magnitude higher than the flux observed in previously reported literature from fields. During this period, the concentrations of HONO in both of the chambers was higher in the daytime than that nighttime, and the concentration of HONO in blank chamber reached the maximum of 18.88 ppbv at noon on the 5th day after fertilization. HONO and NO2 in the sample chambers showed opposite diurnal profiles. The field observation results suggested that the high HONO flux is mainly from the direct emission of soil rather than from the heterogeneous reaction of NO2. Agricultural fertilization will affect the balance of the HONO budget, and then affect the atmospheric oxidation in the North China Plain.

Plant C2 domain proteins play essential biological functions in numerous plants. In this study, 180 soybean C2 domain genes were identified by screening. Phylogenetic relationship analysis revealed that C2 domain genes fell into three distinct groups with diverged gene structure and conserved functional domain. Chromosomal location analysis indicated that C2 domain genes mapped to 20 chromosomes. The transcript profiles based on RNA-seq data showed that GmC2-58, GmC2-88, and GmC2-148 had higher levels of expression under salt, drought, and abscisic acid (ABA) treatments. GmC2-148, encoding a cell membrane-localized protein, had the highest level of response to various treatments according to real-time quantitative polymerase chain reaction (RT-qPCR) analysis. Under salt and drought stresses, the soybean plants with GmC2-148 transgenic hairy roots showed delayed leaf rolling, a higher content of proline (Pro), and lower contents of H2O2, O2– and malondialdehyde (MDA) compared to those of the empty vector (EV) plants. The results of transgenic Arabidopsis in salt and drought treatments were consistent with those in soybean treatments. In addition, the soybean plants with GmC2-148 transgenic hairy roots increased transcript levels of several abiotic stress-related marker genes, including COR47, NCDE3, NAC11, WRKY13, DREB2A, MYB84, bZIP44, and KIN1 which resulted in enhanced abiotic stress tolerance in soybean. These results indicate that C2 domain genes are involved in response to salt and drought stresses, and this study provides a genome-wide analysis of the C2 domain family in soybean.

Corneal infection is an important cause of corneal damage and vision loss. In this work, aminoglycoside antibiotics were grafted onto polymer brushes modified contact lens through dynamic chemical bonds between polyphenol hydroxyls and phenylboronic acid. Both in vitro and in vivo antibacterial tests demonstrated the great promise in prevention of bacterial keratitis which could be attributed to the enhanced the retention time and drug bioavailability.

Repetitive thermal loads inducing damage behaviors of ITER grade tungsten (W) have been investigated using an electron beam device EBMP-30. The metallographic observation, backscattered electron scanning electron microscopy, electron backscattered diffraction, atomic force microscopy analysis and tensile tests were carried out after the repetitive heat loads. Results indicate that there are negligible effects on the microstructures, surface morphologies and mechanical properties with the absorbed power densities (APD) lower than 10 MW/m2. While serious damages including the severe surface roughness with protruding structures along grain boundaries, and significant grains coarsening with the evolution of the grain shape occur undesirably due to the full recrystallization during the repetitive 30 MW/m2 heat loads. Furthermore, after exposed to an APD of 30 MW/m2 with 50 heat loads, the tensile properties deteriorate dramatically, resulting in a limited ultimate tensile strength of only 328 MPa and even a zero total elongation at 300 °C. The relationships between the thermal loads, microstructures evolution and degradation of mechanical properties have been analyzed.

NO3 radicals can clean the atmospheric primary contaminants during the night. However, it can also effect the formation of secondary organic aerosol (SOA) and nitrate, which may worsen air quality. We report field observations of NO3 radicals with a home-made long path differential optical absorption spectroscopy (LP-DOAS) at a rural site in the polluted North China Plain in the summer of 2014. The detection limit (1σ) of NO3 with 3.4 km optical path was 3.4 ppt. The observed mean NO3 mixing ratios were 21 ppt with the maximum value of 104 ppt. The average calculated production rates and steady state lifetime of NO3 were 952 ppt/h and 103 s, respectively. The increase of both PM2.5 (>60 μg/m3) and RH (>60%) would result in an increase of the loss of NO3. The proportion of indirect losses rise with the increase of RH (>50%). The fitting kNO3 ranged from 0.0018 to 0.012 s−1 while γN2O5 was 0.0012 to 0.072. The ratios of direct loss ranged from 20.95% to 90.36% with an average of 56.81% during the campaign.

Context: The main objective of the current study is to improve the water solubility of florfenicol (FF) and evaluate changes in its pharmacokinetics and anti-inflammatory activity.Materials...

Nano-structured metals have been explored as self-healing materials for radiation damage due to vacancy-interstitial recombination at interfaces, such as grain boundaries (GBs) in nanocrystals (NCs) and free surfaces in nanoporous metals (NPs). The annihilation in copper was recently proposed to be via the interstitial-emission (IE) from the GB. However, whether the IE is applied as a possibly universal mechanism in other NPs and NCs deserves further investigation. The interstitial is often considered to overcome a large binding energy with the GB/surface to migrate out of the GB/surface and induce annihilation. In this work, with emphasis on the IE in tungsten where the interstitial is exceptionally tightly bound to the tungsten GB/surface, we found that the interstitial only needed to migrate over a small distance from the GB/surface to recombine with the vacancy nearby at a small energy barrier. During the process, the annihilation region around a static interstitial at the GB/surface propagated or extended greatly to the adjacent bulk area. The annihilation was found to be via the IE from the GB/surface or coupled vacancy hop with the IE. The ratio of the interstitial-GB/surface binding energy to the trapping-radius of the GB/surface for the interstitial was proposed to be a better qualitative indicator for the difficulty in the IE than the binding energy. Given that the IE works in the investigated NPs and NCs tungsten, iron and copper where the interstitials of distinct configurations bind with the GBs/surfaces at diverse levels, the IE mechanism may work universally in various nano-structured metals.

Annealing of a tungsten alloy containing 0.5 wt% zirconium carbide (WZC) in hydrogen atmosphere induced hydrogen embrittlement, which was investigated by exploring the evolution of the tungsten grain size and orientation, the second phase particles distribution, and the tensile properties of the hydrogen-containing and hydrogen-free WZC samples. Thermal desorption spectroscopy used to determine the hydrogen retention revealed a broad hydrogen desorption peak at 1000 – 1300 K, whose hydrogen origin was attributed to the trapping sites in the non-stoichiometric ZrCx of the WZC samples after annealing in hydrogen atmosphere at 1300 °C. Hydrogen retention resulted in the degradation of mechanical properties including strength and ductility and in the deterioration of the ductile-to-brittle-transition behavior. The results emphasize the importance of the atmosphere choice for annealing tungsten materials to avoid hydrogen embrittlement and to ensure good mechanical properties.

Recrystallization and thermal shock fatigue resistance behavior of nanoscale ZrC dispersion strengthened bulk tungsten alloys (W-0.5 wt% ZrC, WZrC) as potential candidates for plasma-facing components were investigated. By employing heat treatments with isochronal experiments, the evolution of the tungsten grain size/orientation, second phase particle distribution, thermal conductivity and mechanical properties were systematically studied. The effects of edge-localized mode like transient heat events on the as-rolled and recrystallized WZrC were investigated carefully. Pulses from an electron beam with durations of 1 ms were used to simulate the transient heat loading in fusion devices. The cracking thresholds, cracking mechanisms and recrystallization under repetitive (100 shots) transient heat loads were investigated. Results indicate that the cracking threshold of all the WZrC samples is 220–330 MW/m 2 (corresponding to a heat load parameter F = 7.0–10.4 MJ/m 2 s 1/2 ) at room temperature and the heat bombardment induced recrystallization occurs at a heat parameter of 10.4 MJ/m 2 s 1/2 .

An ultrafine ZrC nanoparticles dispersion strengthened sub-micrometer grained W-0.5 wt% ZrC alloy (W-ZrC) were fabricated by an improved ball milling and spark plasma sintering (SPS) process. The as prepared W-ZrC has an average grain size of ∼0.86 μm with an average second-phase particle size of 24 nm. The thermal stability and thermal shock resistance of this W-ZrC alloy were investigated systemically by comparison with the reported rolled specimens. For this W-ZrC alloy, the evolution of microstructure with annealing temperature indicates that the occurrence temperature of grain growth is up to 1400 °C–1500 °C, which is higher than that of the as-rolled one (∼1350 °C). Moreover, the crack threshold (100 shots) at room temperature is in the range of 0.22−0.33 GW/m2, which is similar to that of most carbide dispersion strengthening tungsten alloys. In addition, a quantitative relationship between Vickers micro-hardness and grain size of sintered W-based alloys has been proposed.

Bulk pure tungsten (W), W-0.5 wt%TiC (WTC05) and W-1 wt%Y2O3 (WY10) materials were prepared by a developed two-step hot-pressing (HP) sintering method. Metallographic observation, SEM and TEM characterization were conducted to obtain the information of material microstructures. The results indicate that a small amount of TiC or Y2O3 addition could effectively improve the sinterability and reduce the grain size of the HP sintered WTC05 and WY10 alloys. The relative density of WTC05 and WY10 reaches as high as 99%, and the average grain size of WTC05 and WY10 are 2.61 μm and 3.57 μm, respectively, which are several times smaller than that of pure W. Among the three W materials, pure W has the poor tensile performance with insufficient strength and ductility, WTC05 has the highest tensile strength with the ultimate tensile strength of 1082 MPa at 300 °C, and WY10 has the best ductility and moderate strength. The relationship between the microstructures and the tensile properties has been investigated, and suggestions on microstructure parameters have been proposed for preparing high performance W-based materials.

Copper alloys are promising heat sink materials in future fusion reactors owing to the high thermal conductivity and good mechanical properties at medium temperatures. In the present study, aiming at enhancing the strength of copper while keeping the high thermal conductivity, nanoscale W particle dispersion strengthened Cu alloys with different W content of 2 at% (2.6 vol%), 5 at% (6.5 vol%) and 8 at% (10.3 vol%) were fabricated through ball-milling and spark plasma sintering (SPS). The effects of nanoscale W particles on the microstructure, mechanical properties and thermal conductivity of the Cu–W alloys were investigated. The average size of tungsten particles dispersed in copper matrix is 43 nm. The dispersion of W nanoparticles in copper could significantly refine the grain and improve the strength of Cu alloys. The average grain size of Cu-2at%W, Cu-5at%W and Cu-8at%W is as small as 0.84 μm, 0.65 μm and 0.54 μm, respectively. The tensile strength of Cu-8at%W reaches 495 MPa and the elongation is 10.6% at room temperature. The grain size refinement of Cu–W alloys can be attributed to the pinning effects of nanoscale W particles dispersed in the Cu matrix. Although the addition of W nanoparticles leads to a decrease in thermal conductivity, the thermal conductivity for all Cu–W samples is still above 300 Wm-1K-1 at room temperature.

Terminal ballistic performance of high-strength projectiles penetrating into metallic targets is mostly concerned by both weapon and armor designers. Most existing works are concentrated on the rigid-eroding penetration regime, and limited studies have addressed the rigid-deforming-eroding penetration regime. In this paper, nineteen shots of hemispherical nosed D6A steel projectiles penetration test on 5A06-H112 aluminum targets is conducted with a wide range of velocities (696 m/s–1870 m/s). The non-monotonic dependence of depth of penetration (DOP) on the impact velocity is observed, which successively corresponds to the three penetration stages, i.e., rigid projectile penetration, deforming projectile penetration without eroding and eroding projectile penetration. Then, for the non-monotonic rigid-deforming-eroding projectile penetration regime, the applicability of the existing six classical theoretical models for both rigid and eroding projectile penetrations is evaluated. Furthermore, the transition velocities (the upper limit of rigid penetration and the lower limit of eroding penetration) are discussed and an empirical judgement criterion for the occurrence of non-monotonic dependence is proposed. Finally, by conducting the dynamic compression test, quasi-static tension test under varying temperature, etc., the Johnson-Cook model parameters for the present target and projectile are calibrated and validated by numerically simulating the present test. Keywords: Projectile, Penetration, Depth of penetration, Alekseevskii-Tate model, Johnson-Cook model

The cubic Ca/Ta-substituted Li6.55(La2.95Ca0.05)(Zr1.5Ta0.5)O12 (LLCZTO) electrolytes were synthesized at 800 °C with Li3BO3 as additives. The optimal amount of Li3BO3 and its influences on the microstructure, crystal structures, Li+ conductivity and the stability of the Li6.55(La2.95Ca0.05)(Zr1.5Ta0.5)O12 were studied by SEM, XRD and EIS. Among all the samples, when the molar ratio of Li3BO3 to the Li6.55(La2.95Ca0.05)(Zr1.5Ta0.5)O12 is 4:5, the highest Li+ conductivity of 1.33 × 10−4 S cm−1 at 30 °C is obtained. When the LLCZTO samples are exposed in air, the Li+ conductivity is deteriorated possibly owing to the side reactions between the LLCZTO and the H2O or CO2 in the air. The Li3BO3 addition can alleviate such deterioration of the Li+ conductivity.

The rock near-infrared spectrum contains information of its composition and structure. The interpretation of rock near-infrared spectrum is one of the important approaches in the qualitative and quantitative analyses of the alteration minerals in rock. The rock near-infrared spectra are classified using optimized fuzzy C-means clustering algorithm, and the main mineral composition is obtained for different rock samples through the analysis of cluster centers. The minimum Spectral Correlation Coefficient is used as the objective function to classify the simulation data. In this study, the classification method was first tested for parameter setting using simulation data, which was the mixture of several standard mineral spectra quantified in terms of reflectivity in the near-infrared band. Classification accuracies under different fuzzy index values are compared. When the fuzzy index value is 1.5, the classification accuracy of the simulation samples is 83%. The initial values of different cluster ...

The feasibility and toughening efficiency of the short tungsten fibre reinforcement on tungsten were investigated in W f /W composites fabricated by powder metallurgy method of spark plasma sintering. Fibres in the composites presented a Z-free laminar structure. Partial recrystallization of fibre grains occurred but fibre crack or damage was not detected. Fracture energy of W f /W composites was estimated in tensile tests, and the results indicated great toughness improvement over pure tungsten in virtue of frictional pullout and plastic deformation of fibres, and matrix-fibres interfacial debonding since 873 K. The specimen with mass fraction of 10% and fibre diameter of 100 µm exhibits the largest elongation of 9±1.1% and the highest ultimate strength of 482±13 MPa at 873 K.

In order to study the sources, chemical evolutions and impacts on air quality of BTX (benzene, toluene, xylene, etc.) in a typical unban area, a field campaign was conducted with our homemade differential optical absorption spectroscopy (DOAS) instrument in May 2014 at the North part of First Ring Road of Hefei. During the entire measurement, BTX showed high levels in the morning and at night except toluene and phenol. The observed average of benzene is 5.11 mu g m(-3), toluene is 19.15 mu g m(-3), m-xylene is 14.74 mu g m(-3), p-xylene is 1.47 mu g m(-3), phenol is 0.67 mu g m(-3), which are at a low pollution level compared with other cities. The ratios of toluene to benzene range from 1.6 to 8 and the correlation coefficient R of benzene and CO is about 0.88, suggesting the main source of local BTX is traffic emissions. Phenol shows negative correlation with benzene (R = 0.87) in the afternoon, which means that the oxidization of benzene by OH radicals is an important source of phenol. The relations with meteorological conditions were also disscussed, indicating the contribution of solvent evaporation from nearby point sources to toluene in the afternoon. Wind speed is another important factor to the concentration distribution of BTX. The correlation coefficient R of benzene and PM2.5 is 0.83, inferring the influence of street traffic emission on roadside pollution levels.

Exploring Earth-abundant electrocatalysts that are highly efficient, low cost, and stable for the oxygen evolution reaction (OER) are critical to energy storage and water splitting. Metal–organic frameworks (MOFs) have been regarded as superior electrocatalysts due to their atomically dispersed metal ions. Currently, MOFs have been widely studied as templates to fabricate electrocatalysts through thermal annealing. Here, we report a novel synthetic approach to fabricate a Ni–S/MIL-53(Fe) electrode by electrodepositing sulfur-engineered amorphous nickel hydroxides on MIL-53(Fe) nanosheets. The obtained binder-free, self-supported Ni–S/MIL-53(Fe) shows high OER activity with overpotentials of 256 and 298 mV to achieve 10 and 100 mA cm−2, respectively. Moreover, it also exhibits excellent electrochemical stability with no obvious degradation at 100 mA cm−2 for at least 40 h. The new findings may pave a new avenue for designing and fabricating low-cost catalysts with high efficiency for electrochemical applications.

Glaucoma is an optic neuropathy characterized by progressive degeneration of retinal ganglion cells (RGCs). Aberrations in several cytoskeletal proteins, such as tau have been implicated in the pathogenesis of neurodegenerative diseases, could be initiating factors in glaucoma progression and occurring prior to axon degeneration. Developmentally regulated brain protein (Drebrin or DBN1) is an evolutionarily conserved actin-binding protein playing a prominent role in neurons and is implicated in neurodegenerative diseases. However, the relationship between circulating DBN1 levels and RGC degeneration in glaucoma patients remains unclear. In our preliminary study, we detected drebrin protein in the plasma of glaucoma patients using proteomic analysis. Subsequently, we recruited a total of 232 patients including primary angle-closure glaucoma (PACG), primary open-angle glaucoma (POAG) and Posner-Schlossman syndrome (PS) and measured its DBN1 plasma levels. We observed elevated DBN1 plasma levels in patients with primary glaucoma but not in patients with PS compared to nonaxonopathic controls. Interestingly, in contrast to tau plasma levels increased in all groups of patients, elevated drebrin plasma levels correlated with retinal nerve fiber layer defect (RNFLD) in glaucoma patients. To further explore the expression of DBN1 in neurodegeneration, we conducted experiment of optic nerve crush (ONC) models, and observed increased expression of DBN1 in the serum as well as in the retina and then decreased after ONC. This result reinforces the potentiality of circulating DBN1 levels are increased in glaucoma patients with neurodegeneration. Taken together, our findings suggest that circulating DBN1 levels correlated with RNFLD and may reflect the severity of RGCs injury in glaucoma patients. Combining measurement of circulating drebrin and tau levels may be a useful indicator for monitoring progression of neurodegenerative diseases.

Thermoresponsive metal–organic nanotube modified (MONT–pNIPAM, pNIPAM = poly N-isopropylacrylamide) sponge was synthesized using the dip-coating method and served as an adsorbent for endocrine-disrupting compounds (EDCs) and pharmaceuticals/personal care products (PPCPs) removal. The material was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and N2 sorption–desorption. Nonlinear regression-based equations were derived to optimize pH and ionic strength during process. Though thermoresponsive polymer phase transition between dissolve and aggregate, realizing the adsorption tunnel “ON-OFF” under the temperature control. Adsorption kinetics and isotherms were investigated on the basis of a static experiment. The pseudo-second-order kinetic model and the Langmuir isotherm were fitted well to characterize adsorption. At an initial concentration of 50 mg L−1, maximum adsorption capacity were 128 mg/g, 184 mg/g and partition coefficient were 1.09 mg g−1 μM−1, 1.13 mg g−1 μM−1 for dibutyl phthalate (DBP) and parachlorometaxylenol (PCMX), respectively. The density-functional theory (DFT) was applied to calculate the interaction energy and investigate the possible mechanism. Combining the experimental data with theoretical calculation, results demonstrated that the MONT–pNIPAM sponge was a highly efficient adsorbent material that was suitable for the removal of EDCs/PPCPs from water.

A clear understanding on the H/He plasma implantation behavior in the plasma facing materials is a key issue to manage the implanted H/He in a future nuclear fusion reactor. In this work, the microstructure evolution of pure tungsten after low-energy (100 eV) and high-fluence (1023~1024 /m2) helium ion implantation was investigated by the synchrotron grazing incidence X-ray diffraction (S-GIXRD) and nanoindentation. Benefiting from the depth dependence of S-GIXRD and nanoindentation, it was found that the unimplanted W surface layer was composed of two zones: the compressed zone with a thickness of ~56 ± 2 nm under the top surface, which was introduced by the mechanical polishing, and the unaffected matrix. The helium implanted W surface layer was composed of four zones along the direction from the top surface to deep depth: the compressed zone with a thickness of ~46 ± 10 nm, transition zone with a thickness of ~146 ± 14 nm, expanded zone, and the matrix. The compressed zone becomes thinner after He implantation possibly owing to the formation of He-complexes. The expanded zone resulted from the helium atoms entering into the tungsten lattice, while the transition zone is a result of competition between the expanding and compressing effects.

The Li 6.4 La 3 Zr 1.7 M 0.3 O 12 (M = Mo and Cr) and Li 7 − 2 x La 3 Zr 2 − x W x O 12 ( x = 0.1–0.5) solid lithium-ion conductors were prepared by conventional solid state reaction method. The results indicate that partial substitutions by W and Mo ions can stabilize the garnet-like cubic phase of Li–La–Zr–O at room temperature, while the Cr ions substitution cannot even at a content of 15 mol%. The total conductivity of the Li 7 − 2 x La 3 Zr 2 − x W x O 12 lithium conductor is the highest at x = 0.2 (8.7 × 10 − 5 S/cm), and decreases with the increasing W substituting concentration. The Li 6.4 La 3 Zr 1.7 Mo 0.3 O 12 has a higher total conductivity than that of Li 6.4 La 3 Zr 1.7 W 0.3 O 12 . Different from one apparent peak in the Li 7 La 3 Zr 2 O 12 samples, two prominent relaxation-type internal friction peaks related to the short range diffusion of lithium ions were observed in each W or Mo substituted Li 7 La 3 Zr 2 O 12 compounds. The high-temperature IF peaks locate at about 365.9 K and 358.9 K at 1 Hz, corresponding to an activation energy of 0.49 and 0.51 eV for the W and Mo substituted Li 7 La 3 Zr 2 O 12 compounds, respectively. Considering the crystalline structure, it was suggested that the lithium ionic diffusion between 48g(96h)-24d corresponds to the low-temperature peak and 48g(96h)-48g(96h) to the high-temperature peak.

Graphene (G) and graphene oxide (GO) were added into epoxy resin (EP) respectively via chemical modification and physical ultrasound technology to improve the tribological behaviour of EP coating. The topographies of G and GO were detected by scanning probe microscopy. The chemical structures of the fillers before and after modification were identified by Fourier transform infrared spectrometer. The across-section topographies of the coatings were detected by scanning electron microscopy. The tribological behaviour of the coatings was evaluated by UMT-3 tribology tester, surface profiler and scanning electron microscopy. The results revealed that the coefficient of friction of the coatings decreased, and the wear resistance of the coatings improved with the addition of the G and GO. GO could improve the tribological performance of EP further compared to G. When containing 0.5 wt% G and 0.75 wt% GO, the coatings had the lowest coefficient of friction and best wear resistance. When the contents of G reached 0.75 wt%, and GO reached 1 wt%, the tribological performance of the composite coatings decreased as a result of the agglomeration of the fillers. Finally, the anti-friction and anti-wear mechanisms of G-EP and GO-EP composite coatings were discussed in detail based on the results obtained in the preceding texts. Copyright © 2016 John Wiley & Sons, Ltd.

AIM: To investigate the role of tumor necrosis factor-alpha (TNF-α) in zebrafish retinal development and myelination. METHODS: Morpholino oligonucleotides (MO), which are complementary to the translation start site of the wild-type embryonic zebrafish TNF-α mRNA sequence, were synthesized and injected into one- to four-cell embryos. The translation blocking specificity was verified by Western blotting using an anti-TNF-α antibody, whole-mount in situ hybridization using a hepatocyte-specific mRNA probe ceruloplasmin (cp), and co-injection of TNF-α MO and TNF-α mRNA. An atonal homolog 7 (atoh7) mRNA probe was used to detect neurogenesis onset. The retinal neurodifferentiation was analyzed by immunohistochemistry using antibodies Zn12, Zpr1, and Zpr3 to label ganglion cells, cones, and rods, respectively. Myelin basic protein (mbp) was used as a marker to track and observe the myelination using whole-mount in situ hybridization. RESULTS: Targeted knockdown of TNF-α resulted in specific suppression of TNF-α expression and a severely underdeveloped liver. The co-injection of TNF-α MO and mRNA rescued the liver development. Retinal neurogenesis in TNF-α morphants was initiated on time. The retina was fully laminated, while ganglion cells, cones, and rods were well differentiated at 72 hours post-fertilization (hpf). mbp was expressed in Schwann cells in the lateral line nerves and cranial nerves from 3 days post-fertilization (dpf) as well as in oligodendrocytes linearly along the hindbrain bundles and the spinal cord from 4 dpf, which closely resembled its endogenous profile. CONCLUSION: TNF-α is not an essential regulator for retinal neurogenesis and optic myelination.

The mechanical properties and thermal conductivity of W-0.5 wt.% TaC alloys prepared by spark plasma sintering as well as ordinary sintering followed by hot rolling and annealing treatment, respectively, were investigated. Tensile tests indicate that below 600 °C there is no tensile plastic deformation while at 700 °C the total elongation of spark plasma sintered (SPSed) W-0.5 wt.% TaC is up to 36%, which is about 3.3 times that of spark plasma sintered W samples. In contrast, the tensile strength and total elongation of rolled W-0.5 wt.% TaC are 717 MPa and 10.7% at 250 °C, respectively. The ductile-brittle transition temperature (DBTT) of rolled W-0.5 wt.% TaC is between 200 °C and 250 °C, about 300 °C lower than that of spark plasma sintered W-0.5 wt.% TaC (~ 600 °C). Annealing decreases the DBTT (~ 200 °C) and improves thermal conductivity from 175 to 186 W/m·K at room temperature. Microstructure analyses indicates that TaC could purify and strengthen grain boundaries by capturing impurity oxygen in tungsten to form Ta2O5. The results indicate that strength, ductility and thermal conductivity can be improved by purifying, hot rolling and subsequent annealing.

A design combining the advantages of oxide dispersion-strengthening, grain-boundary strengthening and hot-swaging leads to a high performance W-0.2%Zr-1%Y2O3 alloy with enhanced strength and ductility. The Y2O3 particles in tungsten could improve the strength and high-temperature properties, while trace Zr (0.2 wt%) could getter oxygen impurity and enhance grain boundary cohesive strength.

To enhance the toughness of tungsten based on the extrinsic energy dissipation mechanism, tungsten fibre net-reinforced tungsten composites (W/Wf) containing different tungsten fibre net layers were produced by spark plasma sintering method (SPS). The number of tungsten fibre net layers is 2, 4, 6, and 8, corresponding to a fraction of tungsten fibres as 11.35, 23.90, 32.78, and 39.75 wt%, respectively. The relative density of all SPSed samples is as high as 96.3–98.1% depending upon the fibre content. Close integration at low fibre content but a few voids at higher fibre content were detected between the fibres and matrix. Tensile tests indicate that the plasticity of W/Wf composites is higher than that of pure tungsten, which can be ascribed to the fibres pullout, interface debonding, and plastic deformation of fibres. In particular, the composite with four layers of tungsten fibre net exhibits the largest plasticity owing to the good bonding between the fibres and matrix.

Thermal shock fatigue resistance behaviors of a series of rolled W-0.5 wt%ZrC materials (WZC) fabricated using tungsten powders with different powder grain sizes of 0.2 μm (0.2WZC), 0.5 μm (0.5WZC) and 2.8 μm (2.8WZC) were investigated by simulating the effects of edge-localized modes in fusion devices like transient heat events on these WZC specimens. The as prepared three different specimens exhibit different cracking thresholds and cracking patterns under repetitive (100 shots) transient heat loads. The cracking thresholds of the as-rolled 0.2WZC and 0.5WZC are in the range of 0.22–0.33 GW/m2, but

The application of garnet-type solid electrolytes in all-solid-state Li metal battery is seriously impeded by the lithium dendrite and resultant short-circuit. To explore its growth mechanism, in this work, a special asymmetric cell configuration is designed with a porous Li6.55La2.95Ca0.05Zr1.5Ta0.5O12 (LLCZTO) electrolyte between two mutually perpendicular Li metal strips. Besides the generally perceived lithium dendrite growth through grain boundaries, it is witnessed for the first time that lithium dendrite could also penetrate and break the LLCZTO grains, i.e., intragranular growth. Furthermore, uniform distributed lithium spherical particles, instead of lithium dendrite, are found on the surface of LLCZTO with Au-coating, demonstrating the beneficial effect of Au layer on restraining lithium dendrite growth. These findings shed new light on the growth mechanism and inhibition measures of lithium dendrite and would be helpful for the future research of all-solid-state Li metal battery with garnet-type solid electrolytes.

Dense fine-grained pure W, W–1.0 wt.%Zr (WZ), W–1.0 wt.%ZrC (WZC) and W–1.0 wt.%Zr–1.0 wt.%ZrC (WZZC) alloys were fabricated by spark plasma sintering. The grains in WZ and WZZC alloys are stable at annealing temperatures below 1400 °C (1 h), while the grains in pure W grow significantly above 1100 °C annealing. The tensile tests indicate that WZ is ductile already at 400 °C, which is about 200 °C lower than that for pure W. WZC exhibits higher hardness at room temperature than pure W. The ultimate tensile strength of WZC at 600 °C is 798 MPa, about 2.6 times that of pure W. Based on microstructural analysis, the good thermal stability of tungsten grains in WZ and WZZC samples is suggested to be originated from the W–Zr–O and/or Zr–C–O particles which are dispersed on or near the grain boundaries of tungsten and inhibit their migration. The improved tensile properties of the WZ, WZC and WZZC alloys originate (i) from the enhanced GB cohesion by Zr micro-alloying and (ii) from dispersion strengthening by nano-sized ZrC particles.

In this study, equal-channel angular pressing (ECAP) was employed to refine the grain size of tungsten at relatively low temperatures. The small punch (SP) test results show that the ultrafine-grained tungsten appears an evident improvement in both strength and ductility compared with primary coarse-grained tungsten. The analysis results from SP test data indicate that the ductile-to-brittle transition temperature (DBTT) of the ultrafine-grained tungsten decrease to 386 °C and 322 °C due to the ECAP processing at 800 °C and 950 °C, respectively. The reason of the improvement in both strength and ductility of the ultrafine-grained tungsten produced by ECAP is discussed.

A novel screen-printed cell-based electrochemical sensor was developed to assess bacterial quorum signaling molecules, N-acylhomoserine lactones (AHLs). Screen-printed carbon electrode (SPCE), which possesses excellent properties such as low-cost, disposable and energy-efficient, was modified with multi-walled carbon nanotubes (MWNTs) to improve electrochemical signals and enhance the sensitivity. Rat basophilic leukemia (RBL-2H3) mast cells encapsulated in alginate/graphene oxide (NaAgl/GO) hydrogel were immobilized on the MWNTs/SPCE to serve as recognition element. Electrochemical impedance spectroscopy (EIS) was employed to record the cell impedance signal as-influenced by Pseudomonas aeruginosa quorum-sensing molecule, N−3-oxododecanoyl homoserine lactone (3OC12-HSL). Experimental results show that 3OC12-HSL caused a significant decrease in cell viability in a dose dependent manner. The EIS value decreased with concentrations of 3OC12-HSL in the range of 0.1–1 μM, and the detection limit for 3OC12-HSL was calculated to be 0.094 μM. These results were confirmed via cell viability, SEM, TEM analysis. Next, the sensor was successfully applied to monitoring the production of AHLs by spoilage bacteria in three different freshwater fish juice samples which efficiently proved the practicability of this cell based method. Therefore, the proposed cell sensor may serve as an innovative and effective approach to the measurement of quorum signaling molecule and thus provides a new avenue for real-time monitoring the spoilage bacteria in freshwater fish production.

W–Ni–N coatings were fabricated by direct current magnetron sputtering technique. The influence of Ni content on the microstructure, surface morphology and mechanical properties of coatings was investigated by using X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, atomic force microscopy, nanoindentation and scratch tests. The results showed that the addition of Ni into W–N coatings induced a change of grain morphology from polygon to granular shape leading to the reduction in contact area between the coating and the substrate. The roughness of coatings also decreased upon the addition of Ni. Therefore, the adhesion strength of W–Ni–N decreased from 60 to 38 N as Ni content is increased from 0 to 21 at.%. In contrast, the hardness increased slightly at first and then decreased with Ni concentrations. The maximum hardness of 38 GPa was obtained at 10.2 at.% Ni, corresponding to a composite structure consisting of nc-W2N + nc-Ni3N + nc-Ni.

Pure W, W–0.2wt%Zr (WZ), and W–0.2wt%Zr–1.0wt%Y2O3 (WZY) with a relative density of above 97% were fabricated by spark-plasma-sintering method. The tensile tests indicated that the WZ and WZY alloys exhibited a DBTT between 400 and 500 °C, about 200 °C lower than pure W. The ultimate tensile strength of WZY alloy at 700 °C is 534 MPa, which is 81% and 58% higher than those of WZ alloy (295 MPa) and pure W (337 MPa), respectively. The grain size of WZY alloy is about 3.2 μm, smaller than that of WZ alloy and pure W. Besides, at room temperature the fracture strength and hardness of the WZY alloy is higher than that of pure W. The improved mechanical property of the WZY alloy was suggested to be originated from the enhanced grain boundaries cohesion by Zr micro-alloying and nano-sized yttria dispersion strengthening.

Tungsten carbide (WC) coated tungsten samples were fabricated through spark plasma sintering method by covering a layer of graphite powders on the tungsten substrates. The oxidation behavior in a flowing argon atmosphere containing 0–5 vol.% hydrogen and corrosion behavior in static heavy water have been investigated. It was found that the oxidation rate of WC coated sample is one seventh that of uncoated one at the temperature of 500 °C. However, at 650 °C, both of them underwent severe oxidation and a 40–50 microns thick layer of WO3 and WO2.9 compounds formed on the surface of both samples. Addition of 5 or 1 vol.% hydrogen can completely inhibit the occurrence of oxidation respectively for uncoated or coated samples, within the temperature range of 500–800 °C. Furthermore, corrosion behavior in static heavy water suggested that the uncoated tungsten underwent somewhat corrosion after 20 days’ immersion at 20 °C. In contrast, the corrosion in 60 °C heavy water for 15 days was much severe. However, less corrosion was occurred to the coated samples in both cases. For both kinds of samples, the corrosion products mainly consisted of tungsten oxides and hydroxides.

Nano-sized W–1%La 2 O 3 and W–1%Y 2 O 3 powders were synthesized by sol–gel method followed by hydrogen reduction. The average particle size of the powders is smaller than 50 nm. Microwave sintering method was used for the consolidation of tungsten samples, and a relatively low sintering temperature (1500 °C) and short soaking time (30 min) were used to reduce the grains growth. Nano-sized oxide particles with a size distribution of 10–50 nm were homogeneously dispersed in the tungsten matrix. The relative density, average grain size and Vickers micro-hardness of the microwave-sintered W–1%La 2 O 3 and W–1%Y 2 O 3 samples are 92.4% and 93.6%, 1.1 and 0.7 μm, 6.03 and 4.12 GPa, respectively. The W–1%Y 2 O 3 samples showed better sinterability, finer grains, and higher hardness than the W–1%La 2 O 3 samples.