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Materials with electrically tunable optical properties offer opportunities for novel photon applications. Here it is reported that the electrochemical treatment can control the third-order nonlinear absorption of polyaniline. Under the excitation of 800 nm laser, the film shows strong saturation absorption (SA), and the nonlinear absorption coefficient ranges from −1024.27 to −316.29 cm GW-1 depending on the external voltage. The SA can be attributed to Pauli blocking associated with polaron levels in the band gap, and electrochemical doping can change the feature of polaron levels and, accordingly the nonlinear optical property of the material.

An additional layer of zeolite on the surface of metal oxides results in an increased selectivity as gas sensors. However, there is insufficient knowledge on how interactions between the zeolite and gas-sensitive materials improve gas sensing properties. To increase the area of the interface between the materials and decrease agglomeration, SnO2/ZSM-5 composite nanofibers were synthesized via an electrospinning technique. “Bone joints,” such as ZSM-5 nanoparticles, were present in the composite nanofibers. Analyses of the gas sensing properties show that the selectivity and sensitivity of the sensors to formaldehyde were improved. Electronic surface states and charge transport properties were measured via X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS), respectively. It was inferred from the XPS results that the adsorbed oxygen on the surface of the composite increased considerably, thus improving the sensitivity of the sensors. The results of the EIS and electrical equivalent circuits indicate that the interface of the two materials plays a significant role. A larger interfacial area between the zeolite and SnO2 can increase electron transfer and enhance the sensitivity and selectivity of the sensors. This study provides a strategy to improve the sensing properties of semiconducting metal oxide gas sensors.

The combinative effects of both longitudinal cut (Lc) and transverse cut (Tc), and hot air, vacuum, freeze and catalytic infrared drying (HD, VD, FD and CID) techniques on the physicochemical properties of dried ginger was studied. The physicochemical properties determined were shrinkage, hardness, rehydration rate, color, gingerol content, total phenols and flavonoids contents (TPC and TFC), antioxidant activity and volatile components. Results showed that the Lc reduced the drying time significantly, by 15.12–29.6%, compared with Tc; and improved the physical properties (degree of shrinkage, hardness, rehydration rate) of the dried ginger. However, there was no significant difference between them on the chemical properties of the dried ginger. Among the four drying techniques, CID showed the shortest drying time (1.42–1.84 h) and retained the bioactive ingredients (gingerol content, TPC, TFC, and volatile components) better in the dried products. Overall, the study established that Lc treatment combined with CID had an excellent effect on the quality of dried ginger slices and the overall drying efficiency; and thus, were selected as the optimum treatment and drying method for drying ginger.

The hearing loss induced by aminoglycosides is caused by the permanent loss of mechanosensory hair cells of the inner ear. The aim of the present study is therefore to evaluate the protective effect of Bendavia, a novel antioxidant, on gentamicin-induced hair cell damage in zebrafish lateral lines. The results demonstrated the pretreatment of Bendavia exhibited dose-dependent protection against gentamicin in both acute and chronic exposure. We found that Bendavia at 150 μm conferred optimal protection from either acute or chronic exposure with ototoxin. Bendavia reduced uptake of fluorescent-tagged gentamicin via mechanoelectrical transduction channels, suggesting its protective effects may be partially due to decreasing ototoxic molecule uptake. The intracellular death pathways inhibition triggered by gentamicin might be also included as no blockage of gentamicin was observed. Our data suggest that Bendavia represents a novel otoprotective drug that might provide a therapeutic alternative for patients receiving aminoglycoside treatment.

Ultra high temperature confocal laser scanning microscope is applied to observe the characteristics of the γ↔δ phase transformations at different heating and cooling rates on the surface of duplex stainless steels. It is found that the migration of the δ/γ IB is always the main form of the phase transformation and leads to the continuous decline and final disappearance of the retained γ-phase during the γ→δ phase transformation at different heating rates. Heating rate does not radically later the mode of transformation under the current composition system. Interestingly, the δ-phase inside the γ-phase acts as the nucleation cores and grows more rapidly at the slow heating rate than at the rapid heating rate. During the δ→γ phase transformation, the γ-cells prefer to precipitate along the δ/δ grain boundaries with a flaky pattern, and their fronts are jagged in shape at the slow cooling rate, but in needle-like feature at the rapid cooling rate. The γ-cells also nucleate inside the δ-ferrite grains...

The deep high-temperature, high-pressure Lower Cretaceous Bashijiqike sandstone (buried to depths as great as 6.5-7.1km) is an important natural gas reservoir in Keshen gas field, Kuqa depression of the Tarim Basin. Reservoir quality is a critical risk factor in the development of these ultradeep reservoirs. Integrated approaches incorporating routine core analyses, mineralogical, petrographic, and geochemical analyses have been used to investigate the diagenetic history of these rocks and their impact on reservoir quality with the aim to unravel the mechanisms for maintaining anomalously high porosities in sandstones that are buried to such a great depth. These sandstones are dominantly fine to medium-grained, moderately to good sorted lithic arkoses and feldspathic litharenite. Most primary pores have been lost by mechanical compaction or carbonate cementation, and the reduction of porosity by mechanical compaction was more significant than by cementation. Dissolution of framework grains contributed to the enhancement of reservoir quality. Eogenetic diagenetic alterations mainly include mechanical compaction, precipitation of calcite cements and grain-coating clays; mesogenetic diagenesis is characterized by dissolution of framework grain by organic acids and subsequent precipitation of clay minerals and quartz; infiltration of meteoric water related to teleodiagenesis would result in dissolution of the framework grains. The meteoric leaching events during teleodiagenesis are of great importance for the Bashijiqike sandstones. Grain-coating clay minerals (mixed-layer illite/smectite clays) help to preserve porosity at depth by retarding quartz cementation and pressure solution. The unique burial regime as early-stage shallow burial with late-stage rapid deep burial contributes to porosity preservation in eodiagenesis. Fluid overpressure caused by intense structural compression in the middle Himalayan movement retarded compaction and helped preserve porosity in the late rapid deep burial stage. Anomalously high porosities are mainly found in medium-grained, good sorted sandstones with grain-coating clays, but with low clay and carbonate cement content, of which the porosity is preserved primarily and enhanced secondarily. The lowest porosities are associated with sandstones that are tightly compacted or cemented with carbonates or rich in detrital matrix. Porosity-depth trends may vary significantly with lithofacies due to its differences in textural and compositional attributes. Five lithofacies are defined in terms of detrital composition and texture, type and degree of diagenesis. The reservoir quality prediction models of various lithofacies are constructed, and the results of this study provide insights into mechanisms for maintaining anomalously high porosity and permeability in high-temperature, high-pressure sandstone reservoirs, and may help explain hydrocarbon distribution.

AP1000 primary coolant pipe is made of 316LN austenitic stainless steel. It is a large special-shaped pipe manufactured by integral forging technology. Owing to non-uniform temperature and deformation during forging, coarse grains often occur in the boss sections of the pipe especially in the nozzles’ parts. In the present study, a new forging technology was proposed to control the grain size. The finite element method was used to optimize the forging speed and friction coefficient, then the scale-down experiments were performed for comparison. The forging speed is suggested to be less than 20 mm/s, and effective lubricants should be used to decrease the friction coefficient. The errors of the grain size between the experiment and simulation are less than 20%.

Aminoglycoside-induced hearing loss stems from damage or loss of mechanosensory hair cells in the inner ear. Intrinsic mitochondrial cell death pathway plays a key role in that cellular dysfunction for which no proven effective therapies against oto-toxicities exist. Therefore, the aim of the present study was to develop a new mitochondrial targeting drug delivery system (DDS) that provided improved protection from gentamicin. Particularly, SS-31 peptide-conjugated geranylgeranylacetone (GGA) loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles were constructed successfully via emulsion-solvent evaporation method. The zebrafish lateral line sensory system was used as an in vivo evaluating platform to investigate the protective efficiency against gentamicin. SS-31 modification significantly reduced the activity of mechanoelectrical transduction (MET) channel and gentamicin uptake in zebrafish lateral line hair cells. As expected, SS-31 conjugated nanoparticles showed mitochondrial specific accumulation in hair cells when compared with unconjugated formulations. Furthermore, intracellular SS-31 modified PLGA NPs slightly enhanced mitochondrial membrane potential (MMP, ΔΨm) and then returned to a steady-state, indicating their effect on the respiratory chain complexes in mitochondria. GGA loaded SS-31 conjugated nanoparticles demonstrated the most favorable hair cells survivals against gentamicin when compared with unconjugated groups whereas blank formulations failed to exhibit potency, indicating that the efficiency was attributed to drug delivery of GGA. These results suggest that our constructed mitochondria-targeting PLGA based DDS have potential application in protecting hair cells from ototoxic agents.

The eccentricity of rotor seriously affect the vibration and reliability of aero-engine. Due to the machining error of parts, it is very important to accurately predict the error propagation in assembly. A method based on image recognition and machine learning is proposed to predict the eccentricity of rotor. Firstly, by analyzing and calculating the axial and radial runout error data, the error is mainly concentrated in the first 30 orders of the Fourier series. Secondly, based on the mapping relationship between profile trajectory and eccentricity of rotor, the feature information of the profile trajectory is extracted by constructing the complex domain autoregressive (CAR) model for the radial and axial direction error profile trajectory. Then use the finite element method to calculate the rotor eccentricity. Using the feature information as the input of the neural network, the rotor eccentricity is assembled as the output of the neural network, and the radial basis function (RBF) neural network is built to predict the rotor eccentricity. Theoretical and experimental results show that the proposed method has good enforceability, high accuracy, short calculation time and high engineering application value. In addition, this method can not only be applied to predict the eccentricity of aero-engine rotor flange assembly, but also can be used in the general field of interference fit of assembly.

Benzofuran (BF), benzothiophene (BT), indole (IN), dibenzofuran (DBF), dibenzothiophene (DBT), and carbazole (CA) are typical heterocyclic aromatic compounds (NSO-HETs), which can coexist with polycyclic aromatic hydrocarbons (PAHs) in combustion and pyrolysis conditions. In this work, quantum chemical calculations were carried out to investigate the formation of DBF, DBT, and CA from the reactions of BF, BT, and IN with a cyclopentadienyl radical (CPDyl) by using the hybrid density functional theory (DFT) at the MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p) level. The rate constants of crucial elementary steps were deduced over 600&minus, 1200 K, using canonical variational transition state theory with a small-curvature tunneling contribution (CVT/SCT). This paper showed that the production of DBF, DBT, and CA from the reactions of BF, BT, and IN with CPDyl involved six elementary steps: the addition reaction, ring closure, the first H shift, C&ndash, C cleavage, the second H shift, and elimination of CH3 or H. The cleavage of the C&ndash, C bond was regarded as the rate-determining step for each pathway due to the extremely high barrier. The 1-methyl substituted products were more easily formed than the 4-methyl substituted products. The main products were DBF and 1-methyl-DBF, DBT and 1-methyl-DBT, and CA and 1-methyl-CA for reactions of BF, BT, and IN with CPDyl, respectively. The ranking of DBF, DBT, and CA formation potential was as follows: DBT and methyl-DBT formation &gt, DBF and methyl-DBF formation &gt, CA, and methyl-CA formation. Comparison with the reaction of naphthalene with CPDyl indicated that the reactions of CPDyl attacking a benzene ring and a furan/thiophene/pyrrole ring could be inferred to be comparable under high temperature conditions.

Methoxyphenols, as the main products and tracers of biomass burning, have been demonstrated to play an important role in the formation of secondary organic aerosols. However, their chemical transformation and migration in the atmosphere haven't been well characterized. In this study, detailed gas-phase reaction mechanisms and kinetics of three representative methoxyphenols (guaiacol, creosol and syringol) with OH radicals were investigated by using density functional theory (DFT). The initial reactions of methoxyphenols with OH radicals proceed via two different patterns, including OH-addition and H-atom abstraction. Subsequent reaction schemes of the active intermediates in the presence of O2/NOx are thoughtfully modeled. Catechol, methyl glyoxylate, malealdehyde and carbonyl or carboxyl compounds were confirmed as the dominant oxidation products for guaiacol. As a supplementary study, the formation pathways for the expected products nitroguaiacol and nitrocatechol were presented in high-NO2 conditions. Total and individual rate coefficients are calculated using the MESMER program at 294 K and 1 atm. The lifetimes of guaiacol, creosol and syringol were estimated to be 4.27, 3.56 and 2.98 hours, respectively, which are strongly competitive with the solar photolysis of methoxyphenols.

The lignin pyrolysis products generated by biomass combustion make an essential contribution to the formation of secondary organic aerosols (SOAs). The ozone-initiated oxidation of guaiacol, syringol and creosol, major constituents of biomass burning, were investigated theoretically by using the density functional theory (DFT) method at the MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p) level. Six primary addition reaction pathways and further decomposition routes with corresponding thermodynamic values were proposed. The Criegee intermediates can be excited by small molecules, such as NOx, H2O in the atmosphere, and would further proceed via self-decomposition or isomerization. The most predominant product for ozonation of guaiacol is the monomethyl muconate (P1). At 295 K and atmospheric pressure, the rate constant is 1.10 &times, 10&minus, 19 cm3 molecule&minus, 1 s&minus, 1, which is lies a factor of 4 smaller than the previous experimental study. The branching ratios of the six channels are calculated based on corresponding rate coefficient. The present work mainly provides a more comprehensive and detailed theoretical research on the ozonation of methoxyphenol, which aspires to offer novel insights and reference for future experimental and theoretical work and control techniques of SOAs caused by lignin pyrolysis products.

Science and Technology Major Project of Anhui, Grant/Award Number: 18030701152; Social Development Program (General Project) of Jiangsu, Grant/Award Number: BE2016779 and NY2017015; Policy Guidance Program (Research Cooperation) of Jiangsu, Grant/Award Number: BY2016072-03; National Key Research and Development Program of China, Grant/Award Number: 2016YFD0400705-04, 2017YFD0400903-01 and 2018YFD0700101-02

Three-dimensional/two-dimensional (3D/2D) rare earth Ln3+ (Ln = Er or Eu)-doped BiOBr wrapped with reduced graphene oxide (Bi-Ln/rGO) was obtained via a two-step solvothermal–hydrothermal process. The doping of Ln3+ and the construction of heterojunction between 3D Ln3+-doped BiOBr microspheres and 2D rGO nanosheets were beneficial to the wide absorption of visible light and the efficient separation of photoinduced electrons and holes, further improving the photocatalytic activity of Bi-Ln/rGO composites for RhB photodegradation. The photocatalytic activity of Bi-Ln/rGO was higher than those of pure BiOBr, Ln3+-doped BiOBr, and BiOBr/rGO. The radical-trapping experiments on active species indicated that h+ and ·O2− were mainly responsible for the photodegradation of RhB. The mechanism of the enhanced photocatalytic performance was proposed on the basis of radical-trapping experiments on active species.

In this study, sol-gel process followed by electrodeposition process was used to prepare a ZrO2 coating on the Fe–Al alloy layer. The sol-gel process is prone to produce pores. We studied the effect of pulling speed on the ZrO2 coating. The electrodeposition process was further used to densify the coating. The deposition time had a significant effect on the porosity. The surface and cross-sectional morphology of the coating was observed by scanning electron microscope, and the phase structure was detected by X-ray diffraction. The results revealed that the ZrO2 coating when being pulled at 120 mm/min had the minimum porosity of 6.48%. Almost no pores were found on the surface after three times of 6-min deposition. The thickness of the ZrO2 coating after deposition for 6 min was about 13 μm. The internal Fe–Al alloy bond coat contained FeAl3, Fe2Al5, FeAl and Fe3Al phases, and the external ZrO2 coating contained t-ZrO2 and m-ZrO2 phases.

This work aimed to study the rehydration characteristics of vacuum freeze- (VFD) and hot air-dried (HAD) garlic slices and explain the rehydration mechanism. It was observed that VFD samples had significantly faster water absorption rates than HAD samples. However, VFD samples had lower final moisture contents than the HAD samples. Additionally, the effect slice thickness on rehydration characteristics of samples was lower than that of drying methods. The contact angle and microstructure analysis of dried samples revealed that the strong water wettability and the porous structure contributed to the faster water absorption rate of VFD samples. Moreover, we found and confirmed, for the first time, that numerous air bubbles trapped in the VFD samples hindered the absorption of water. This resulted in a lower water holding capacity in VFD samples compared with HAD samples, which had less air bubbles.

Various drying techniques play an important role in foodstuff preservation. However, the role of different drying techniques on garlic quality is limited. The purpose of this study was to investigate the effect of vacuum freeze-drying (VFD), hot air drying (HAD), infrared hot air drying (IRHAD), relative humidity drying (RHD) and pulsed vacuum drying (PVD) on the physical, rehydration, flavor, bioactive compounds and antioxidant characteristics of garlic slices. Results showed that garlic slices treated with VFD had an attractive color, low shrinkage, low hardness, and the lowest rehydration capacity. The volume shrinkage ratio, thermal stability and storage stability of garlic slices after HAD were the highest. Different dried garlic samples had different specific flavor fingerprints. IRHAD and RHD dried samples showed the highest rehydration capacity, content of bioactive compounds and antioxidant activity. The findings could provide a scientific basis to help in future large-scale production of good quality dried garlic products.

Eugenol is a representative methoxyphenol derived from the pyrolysis of lignin containing a branched alkene group. Its concentration in the atmosphere is equivalent to guaiacol and syringol. In this present paper, the gas phase reaction mechanisms and kinetic parameters of eugenol with hydroxyl radicals (OH) and ozone molecules (O3) were calculated at the M06-2×/6-311+G(3df,2p)//M06-2×/6-311+G(d,p) level. There are two distinct reaction types between eugenol and OH. In particular, Path2 is most favorable in the OH additions, whereas IM16 is most advantageous in H atom abstraction pathways. OH additions have more advantages than H abstraction reactions. Thus, the comprehensive and detailed reaction schemes for the further reactions of IM2 were presented. The main products generated by IM2 are methyl (Z)-3-(2-formylpenta-1,4-dien-1-yl)-2-hydroxyoxirane-2-carboxylate (P2B-4), 2-methoxy-2-oxoacetic acid (P2B-10), 2-allylmalealdehyde (P2B-11) and other carbonyl or carboxyl compounds. As for the reaction of eugenol with O3, the cycloaddition reactions and subsequent oxidative degradation processes were also explored, which yielded the most dominant product 2-(4-hydroxy-3-methoxyphenyl) acetaldehyde (P8-1). The reaction constants of the primary reactions for eugenol with OH and O3 under the temperature range of 225– 375 K were successively calculated by POLYRATE and MESMER program. At 298 K and 1 atm, the respective rate coefficients are 5.91 × 10−11 and 5.48 × 10−16 cm3 molecule−1 s−1 and the corresponding atmospheric lifetimes are 4.70 h and 0.72 h. The short lifetimes suggest that once eugenol enters the atmosphere, it is likely to be rapidly degraded. This work aims to provide theoretical guidance for the photochemical reaction mechanisms of eugenol with OH and O3, and present a reference for more experimental researches.

Scaffolding serves as one construction trade with high importance. However, scaffolding suffers from low productivity and high cost in Australia. Activity Analysis is a continuous procedure of assessing and improving the amount of time that craft workers spend on one single construction trade, which is a functional method for monitoring onsite operation and analyzing conditions causing delays or productivity decline. Workface assessment is an initial step for activity analysis to manually record the time that workers spend on each activity category. This paper proposes a method of automatic scaffolding workface assessment using a 2D video camera to capture scaffolding activities and the model of key joints and skeleton extraction, as well as machine learning classifiers, were used for activity classification. Additionally, a case study was conducted and showed that the proposed method is a feasible and practical way for automatic scaffolding workface assessment.

The purpose of this study was to construct a fusion model using probe-based and non-probe-based fluorescence spectroscopy and low-field nuclear magnetic resonance spectroscopy (Low-field NMR) for rapid quality evaluation of frying oil. Iron tetraphenylporphyrin (FeTPP) was selected as the probe to detect polar compounds in frying oil samples. Non-probe-based fluorescence spectroscopy and low-field NMR were employed to determine the fluorescence changes of antioxidants, triglycerides and fatty acids in frying oil samples. Compared to the models constructed using non-fusion data, the fusion-data models achieved a better regression prediction performance and correlation coefficients with values of 0.9837 and 0.9823 for the training and test sets, respectively. This study suggested that the multiple data fusion method was capable to construct better regression models to rapidly evaluate the quality of frying oil and other food with high oil contents.

The aqueous two-phase system (ATPS) based on ionic liquid (IL) has proven to have excellent extraction performance as a new extraction platform. Nevertheless, the regeneration, recovery and reuse of IL are still a big challenge. Developing a greener and more cost-effective extraction process is a daunting task. Aiming at overcoming this disadvantage, we innovatively proposed a IL-ATPS phase diagram which was formed from [C4mim][CF3SO3] and inorganic salts. The effects of phase-forming salt species and IL concentration on the distribution of syringic acid in IL-ATPS were investigated. The results displayed that the IL-ATPS extraction efficiencies of Na2SO4 and Na2CO3 performed best (96.66 ± 1.01% and 95.11 ± 0.87%, respectively). The IL-ATPS was then used in sequential cycles to assess their efficacy on the IL reusability. The syringic acid was extracted again using the recovered IL, and the extraction efficiency was 94.11 ± 1.06%. In addition, we tested the most prominent systems to extract caffeic acid which provided evidence for the back-extraction routes and the recyclability concept of the vast applicability of caffeic acid and the extraction efficiencies were higher than 96.43 ± 0.24%. This work can lay a good foundation for the sustainable development of IL-ATPS.

Surface description is fundamental in mechanical contact analysis. In this paper, some of the most common approaches for roughness description are first briefly described. Some models for approximating a real rough profile with parabolas that guarantee the preservation of some specific characteristics are presented. The specimens of aluminum alloy with different surface roughnesses are prepared and measured. A data analysis program is developed to identify the measured profile with quadratic functions for different approximating criteria. Based on this, the effect of the approximating criterion and the sampling interval on the surface roughness parameters and the mechanical parameters is then presented and compared. The results show that the surface roughness Ra, asperity height H, and peak radii R increase with increasing surface roughnesses for different approximating criteria. The same root mean square approximating criterion is more suitable for calculating the surface roughness Ra. The asperity height H and peak radii R increase with increasing sampling intervals for all roughnesses, while the trend is opposite for the surface roughness Ra. The sampling interval has little effect on these parameters, especially for smoother surfaces.

In this study, a coupled three-dimensional model of the billet continuous casting mold process was developed to investigate the characteristics of the macroscopic transmission behaviors under different mold electromagnetic stirring (M-EMS) parameters. The mold curvature was also considered during the modeling of electromagnetic and flow fields. The results indicate that the macroscopic physical quantities had nonsymmetrical distributions in the mold because of the mold curvature. However, the influence of mold curvature on the electromagnetic force could be ignored. The horizontal swirling flow caused by the M-EMS became stronger as the current density increased, which enhanced the dissipation of the molten steel superheat and promoted the growth of the solidification shell. However, the flushing of the bias hot jet slowed the growth of the local solidified shell. Meanwhile, the washing effect of the melt flow on the solidification front caused the solute element content near the billet surface to fluctuate. In addition, the distribution of the solute element content became more uneven in the strand transverse direction as the current density increased.

Present-day stress state is significant for petroleum industry and prediction of stress-related geohazards. The Kelasu Belt, located between Southern Tianshan and the bank-land of the Tarim Basin, is a main gas source in China and is extremely active during Himalayan movement. Predicting the in-situ stress of the BSJQK Formation in the Kelasu Belt is difficult due to the ultra-deep tight sandstone reservoir (5500–8500 m depth), with pervasively developed fractures, surrounded by multi-detachment layers and complicated structural association. In this study, we first analyzed the present-day maximum horizontal stress in the BSJQK Formation using imaging logs (FMI-HD, OBMI, EI and CBIL), then carried out the fracture interpretation based on core-image calibration, finally evaluated their hydraulic conductivity integrating well testing, petrophysical experiments and logging interpretation. The average S Hmax orientation in wells B, C, D and E in the Kelasu Belt correspond to 124.76°N (±8.5°), 92.86°N (±4.3°), 143.28°N (±7.1°) and 180.89°N (±4.5°), respectively, which coincides well with the result derived from the focal mechanism solution. The stratigraphic attitude and boundary structure may control the variation of S Hmax orientation. Fracture attitude in wells B, C, D and E correspond to 70°/26°N, 54°/346°N, 81°/239°N and 76°/253°N, respectively and intersect S Hmax at an angle less than 29°. Fracture could increase formation permeability with 1–3 order of magnitudes and provides the main channel for gas migration. Furthermore, the calculation of “Gas Productivity Index per Meter” indicates that fracture density is closely related with gas productivity, which will guide the next fracturing intervals. The N-S or NEE-SWW could be the preferable orientations for drilling trajectory design of horizontal wells.

The technique of colorimetric sensor array (CSA) is proved to be a novel and helpful method to detect and determine the quality of food and beverages with simple, inexpensive, rapid and sensitive advantages. The limit of this technique is considered to be the sensor design. In this study, density functional theory (DFT) at B3LYP/LANL2DZ level was employed to investigate the ability of CSA sensor to bind volatile organic compounds (VOCs). The results showed that silver porphyrin (AgP) is sensitive to trimethylamine (L1), followed by propanol (L2) and N2, whereas O2 and propane (L3), ethyl acetate (L4), butanone (L5), and propionaldehyde (L6) cannot be easily detected by AgP. The analysis of charge distribution indicated that the nature of AgP reacted with VOCs is the electron transfer from Ag atom to porphyrin plane. This theoretical study may be a useful guide for the design of CSA sensor to detect and determine a special analyte.

In this study, the numerical simulations were carried out to analyse the structure of the oxygen lance nozzle, the flow conditions of oxygen and the flow status of molten steel in the converter. Th...

The number, morphology, size and composition of inclusions after deoxidation and alloying in Ti-stabilised stainless steel were investigated. This was carried out by electrolytic extraction of inclusions from steel matrix, followed by microscopic examination. It was found that after the addition of ferrosilicon and manganese, and later aluminium, the composition of inclusions changed from manganese silicate-rich inclusions to alumina-rich inclusions. After tapping and titanium wire feeding, three types of TiN inclusion morphologies were observed, single, twinned and clusters. Both the turbulence and Stokes' collision mechanisms play a considerable role in the formation of TiN clusters.

The behavior and formation mechanisms of inclusions in Ti-stabilized, 17Cr Austenitic Stainless Steel produced by the ingot casting route were investigated through systematic sampling of liquid steel and rolled products. Analysis methods included total oxygen and nitrogen contents, optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The results indicate that the composition of inclusions was strongly dependent on the types of added alloying agents. During the AOD refining process, after the addition of ferrosilicon alloy and electrolytic manganese, followed by aluminum, the composition of inclusions changed from manganese silicate-rich inclusions to alumina-rich inclusions. After tapping and titanium wire feeding, pure TiN particles and complex inclusions with Al2O3-MgO-TiO x cores containing TiN were found to be the dominant inclusions when [pct Ti] was 0.307 mass pct in the molten steel. These findings were confirmed by thermodynamic calculations which indicated that there was a driving force for TiN inclusions to be formed in the liquid phase due to the high contents of [Ti] and [N] in the molten steel. From the start of casting through to the rolled bar, there was no further change in the composition of inclusions compared to the titanium addition stage. Stringer-shaped TiN inclusions were observed in the rolled bar. These inclusions were elongated along the rolling direction with lengths varying from 17 to 84 µm and could have a detrimental impact on the corrosion resistance as well as the mechanical properties of the stainless steel products.

The characteristics of non-metallic inclusions in 347 stainless steel samples taken during a net-shape casting process after different holding times and melting temperatures were investigated using electrolytic extraction and polished cross-sections. The inclusions can be classified into three groups: oxides, composite inclusions and sulphides. Within the first two groups the inclusions were subdivided based on their morphology into the following categories: spherical, irregular and clusters. As the temperature decreased, sulphide and NbC precipitated within the steel melt as well as on the surface of existing oxides. The number density and area fraction of inclusions as well as the total oxygen contents increased with higher melt temperatures and longer holding times. The results obtained from thermodynamic calculations carried out using the FactSage™ commercial software agreed well with the experimental observations. In addition, it has been concluded that turbulent collisions are the dominant mode for ...

The formation and characteristics of non-metallic inclusions in 316L stainless steel produced by the AOD (argon oxygen decarburization)–ladle furnace–continuous casting process were investigated. The morphology and composition of inclusions changed significantly during the refining and casting processes. After de-oxidation with Si/Mn additions, spherical complex inclusions mainly consisting of calcium silicates were observed. The contents of MgO and Al2O3 in these inclusions continuously increased as the steel moved from the AOD through ladle processing to the tundish. As the temperature decreased from the tundish through to solidification, harmful crystals of MgO/Al2O3 spinel were precipitated within the steel melt as well as within the calcium silicate matrix of existing inclusions. The results obtained from thermodynamic calculations carried out using FactSage™ commercial software agreed well with the information derived from evaluation of the industrial samples enabling recommendations to be made for ...

To better understand the behavior, fate and oxidation products of polychlorinated biphenyls (PCBs) in the atmosphere, probing the atmospheric oxidation mechanism and kinetic properties of PCBs is of crucial importance. In this paper, taking 2,4,4′-trichlorobiphenyl (PCB28) as an example, the detailed atmospheric oxidation mechanism initiated by OH radicals was investigated by using quantum chemistry calculations. Studies show that the initial reaction is dominated by OH addition to form the PCB–OH adducts. In the atmosphere, the PCB–OH adducts could further react with O2 either by H-abstraction to form hydroxylated PCBs or by addition to generate peroxy radical intermediates, which subsequently cyclize to bicyclic radicals. Subsequent reactions include O2 addition, NO addition, NO2 elimination and benzene ring breaking. On the basis of the quantum chemical calculation, rate constants of the key elementary reactions at 298 K are calculated. The calculated overall rate constant of PCB28 with OH radicals is 1.25 × 10−12 cm3 per molecule per s with an atmospheric lifetime of 9.3 days. In addition, the effect of substituted chlorine atoms in PCBs to the reaction activity has been discussed.

Controlling the specific ionic interactions between drugs and mesophases particles can enable controlled release systems for proteins. Here we present the interaction of basic nerve growth factor (NGF) with highly homogeneous cubosomes based on the glycerol monooleate–water system where β-casein was employed as a stabilizer. Addition of β-casein leads to modification of the internal cubosomal surface to generate highly negative charge. The colloidal structures were characterized with small angle X-ray scattering and visualized using cryogenic transmission electron microscopy. These nanostructured particles are able to sustain the release of hydrophilic NGF since less than 15% of the protein was released over 24 h. Similarly, cationic 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) immobilized within the mesophase particles provided another specific interactions of the cubosomal surface, from which the release of water soluble bovine serum albumin was retarded. Evaluation of NGF entrapped colloidal dispersions in PC12 cells led to identification of β-casein stabilized cubosomes that induce more than 140% neurite outgrowth enhancing the activity of NGF. Accordingly, the AUC value for RWM administration of NGF-loaded dispersions in guinea pigs was significantly higher than that administrated with NGF, of which the relative bioavailability of the β-casein stabilized dispersions was increased to 337% as compared with free drug.

The adsorption and heterogeneous reactions of ClONO2 and N2O5 on the NaCl (100) surface have been investigated by performing density functional theory (DFT) calculations. Possible adsorption structures, energies and electronic properties of ClONO2 and N2O5 were studied by considering multiple possible adsorption sites without symmetry restriction. The most stable adsorption configurations are a vertical adsorption mode for ClONO2 and a horizontal adsorption mode for N2O5, with the adsorption energies of 14.81 and 13.67 kcal mol−1, respectively. Two possible reactions were proposed on the NaCl (100) surface. Adsorbed ClONO2 and N2O5 could react with HCl or hydrolyze on the NaCl surface to form HNO3 and other gaseous species (Cl2, HOCl and ClNO2). More importantly, ClONO2 and N2O5 can actively participate in the heterogeneous reaction with NaCl to generate Cl2 and ClNO2, which could be photolyzed to produce reactive chlorine atoms. The adsorbed H2O molecule plays an important role in the key elementary step and promotes the formation of the products. The present results rationalize previous experimental studies well and enrich our understanding of the source of halogen atoms in the marine boundary layer.

This study investigates the effect of flat sweep frequency and pulsed ultrasound (FSFPU) pretreatment prior to vacuum pulsation (VP) drying on water migration and quality attributes of okra pods. The results showed that the moisture diffusion was the fastest in VP drying process when FSFPU pretreatment parameters were set as 40 kHz, 25.0 W/L, sweep period 18–180 ms and amplitude ± 1 kHz. In addition, FSFPU pretreatment caused the change of microstructure (villi and xylem), resulting in significant decrease of drying time required. The VP dried okra pods with FSFPU pretreatment had features: i) increased total phenolic contents and antioxidant capacity; ii) no significant changes of total flavonoids contents; iii) a lower chlorophyll degradation (13.5% less), higher hardness and frangibility, and a lower total color change (reduced browning index); iv) reduced negative effects on the flavor. Therefore, the use of FSFPU pretreatment prior to VP drying is suggested.

Freeze-thaw cycles (FTC) pretreatment was employed before the vacuum freeze-drying of garlic slices, aimed at improving the drying process and the quality of the end product. Cell viability, water status, internal structure, flavor, chemical composition and thermogravimetric of garlic samples were evaluated. The results indicated that FTC pretreatment reduced the drying time (22.22%-33.33%) and the energy consumption (14.25%-15.50%), owing to the water loss, the increase in free water, and the formation of porous structures. The FTC pretreatment improved thermal stability, flavor and chemical composition content of dried products. The antioxidant activity of polysaccharides extracted from FTC pretreated dried products was higher than that of the unpretreated dried product due to the reduction in polysaccharide molecular weight. This research could pave a route for future production of dried garlic slices having good quality by using the FTC pretreatment, with lower energy consumption and shorter drying time.

Refrigeration is an effective means of reducing losses in fresh fruit; however, its efficacy as a means of preservation is mostly limited to crops that are not vulnerable to chill injury. Cherry tomato is one of these crops where other supporting processes or storage alternatives are sought. The effect of 10-min post-harvest treatment of cherry tomato with individual or combined application of dual-frequency ultrasound (20/40 kHz) and chemical sanitizers was investigated. The sanitizers used are 200 mg/L sodium dichloroisocyanurate (SD), 40 mg/L peracetic acid (PAA), 40 mg/L peracetic acid with 5% H2O2 (PAAH), and 5% hydrogen peroxide. The results showed that the treatments significantly reduced the natural microbiota (aerobic mesophiles and yeasts and molds) within the values of 0.29–3.10 log CFU/g. The highest inactivation was observed for the PAAH and ultrasound when applied as an individual (2.08–2.32 log CFU/g) and combined (3.07–3.10 log CFU/g) treatment. Also, the ultrasound and combined treatment resulted in higher retention of the total phenolic, and flavonoid contents, but with a loss in firmness of the cherry tomato. Nevertheless, during storage, the treatments when compared with the untreated samples, impede the loss in firmness. The other quality parameters such as pH, total soluble solids, titratable acidity, and maturity index were not affected, which signified that irrespective of the treatment, similar changes take place on the fruit during storage, especially in both control and chemically treated fruit. The combination of 40 mg/L PAAH and 20/40 kHz for 10 min caused ≥3-log CFU/g reduction of the natural microbiota. It mitigated the senescence of the cherry tomato during the refrigerated storage (4 °C), which thereby increased the shelf-life. The results obtained at the end of the storage thereby indicated that the combined treatments could guarantee microbial safety and retain the quality of the cherry tomato.

Aerosol samples from all over the word contained 2-methyltetrol sulfate ester (MTS). We investigated the role of MTS in new particle formation (NPF) with aerosol nucleation precursors, including sulfuric acid (SA), water (W), ammonia (N), methylamine (MA), dimethylamine (DMA), and trimethylamine (TMA). The analysis was performed using quantum chemical approach, kinetic calculation and molecular dynamics (MD) simulations. The results proved that the molecular interactions in the clusters were mainly H-bonds and electrostatic interaction. The negative Gibbs free energy changes for all the studied MTS-containing clusters indicated that the formation of these clusters was thermodynamically favorable. The stability of the clusters was evaluated according to the total evaporation rate. Here, (MTS)(SA) and (MTS)(W) were the most and least stable cluster, respectively. MD simulations were used for time and spatial analysis of the role of the MTS-SA system. The results indicated that MTS can self-aggregate or absorb SA molecules into clusters, larger than the size of the critical cluster (approximately 1 nm), suggesting that MTS can initiate NPF by itself or together with SA.

The theoretical design of a metalloporphyrin-based fluorescence sensor was developed for the discrimination of volatile organic compounds (VOCs). Molecular models of cobalt tetraphenylporphine (CoTPP) with small VOCs were investigated by the density functional theory (DFT) method at the Becke, 3-parameter, Lee–Yang–Parr (B3LYP) and LAN2DZ level. The relative energies of CoTPP and its complexes were calculated at three spin states (low, intermediate, and high) to obtain their optimized geometry structures. Singlets were found to be the most stable states for CoTPP and its complexes, except for CoTPP-oxygen and CoTPP-propanol at triplets. The binding performance was represented by the binding energy (BE), which showed the following order based on the most stable states: propane (L3) < oxygen (O2) < propanol (L2) < hydrogen sulfide (H2S) < propionaldehyde (L6) < nitrogen (N2) < butanone (L5) < ethyl acetate (L4) < trimethylamine (L1). We suggest that the CoTPP-based fluorescence sensor is sensitive to trimethylamine and ethyl acetate, and avoids the interference from propane and oxygen.

It is a significant and challenging task to simultaneously detection of multiple heavy metal ions with convenience, sensitivity and reliability. Herein, a novel ratiometric electrochemical sensing method was established for the simultaneously detection of three main heavy metal ion pollutants (Cd2+, Pb2+ and Cu2+). The sensing platform was constructed by a composite of ferrocenecarboxylic acid functionalized metal-organic framework (MOF), Fc-NH2-UiO-66, and thermally reduced graphene oxide (trGNO), which was designated as trGNO/Fc-NH2-UiO-66. NH2-UiO-66 has porous structure and large specific surface area, which is beneficial to the adsorption and preconcentration of heavy metal ions. The introduction of trGNO and Fc improves the conductivity and electrochemical activity of the MOF material. Moreover, the signal of Fc can be used as internal reference to develop ratiometric detection, which greatly improves the reproducibility and reliability of electrochemical detection. Based on this ratiometric electrochemical sensing platform, the simultaneous, sensitive and reliable detection of Cd2+, Pb2+ and Cu2+ was realized. This work provides a new sensing platform for simultaneous detection of multiple heavy metal ions and greatly expands the application of UiO-66-type MOFs in electrochemical field.

In this study, the magnetically recyclable Fe3O4@C/BiOBr heterojunction with enhanced visible light-driven photocatalytic ability was obtained by two-step solvothermal method. The phase, morphology, and structure of the samples were investigated by XRD, FESEM, HRTEM, and XPS. The Fe3O4@C/BiOBr heterojunction was composed of Fe3O4@C sphere and BiOBr microsphere with diameters of 200 nm and 1000 nm, respectively. The photocatalytic performance of Fe3O4@C/BiOBr composite for RhB was examined under visible light irradiation. The photocatalytic activity of Fe3O4@C/BiOBr composite was much higher than that of pure BiOBr and Fe3O4@C. After 35 min of irradiation, 97% of RhB could be removed with the Fe3O4@C/BiOBr photocatalyst. Based on radical trapping experiments of active species, the mechanism of enhanced photocatalytic performance was proposed. In addition, the superparamagnetic property of the photocatalyst not only allows its easy recyclability by an external magnetic field but also maintains high photocatalytic activity after five cyclic experiments.

This paper investigated the effects of different pretreatments on the drying process and quality characteristics of catalytic infrared (CIR) dried garlic slices. Different garlic samples, including a control (un-pretreated), and samples pretreated with alcohol, alcohol-ultrasound (US + Alcohol) and water-ultrasound (US + Water) were prepared. The effect of different pretreatments on microstructure of garlic was studied. All of the pretreatments decreased the drying time by 9.09%–27.27% compared to the control, while US + Alcohol provided the highest reduction (27.27%). The possible mechanism of improvement in the dehydrating process of garlic samples was proposed. Except for allicin content, the quality characteristics of shrinkage, surface roughness, flavor, color and the microbial content of the US + Alcohol pretreated dried garlic samples were predominately better than the control, alcohol and US + Water pretreated samples. This research provides a new pretreatment technology, to efficiently give rise to a high quality CIR dried garlic products.

SnO2-impregnated zeolite composites were used as gas-sensing materials to improve the sensitivity and selectivity of the metal oxide-based resistive-type gas sensors. Nanocrystalline MFI type zeolite (ZSM-5) was prepared by hydrothermal synthesis. Highly dispersive SnO2 nanoparticles were then successfully assembled on the surface of the ZSM-5 nanoparticles by using the impregnation methods. The SnO2 nanoparticles are nearly spherical with the particle size of ~ 10 nm. An enhanced formaldehyde sensing of as-synthesized SnO2-ZSM-5-based sensor was observed whereas a suppression on the sensor response to other volatile organic vapors (VOCs) such as acetone, ethanol, and methanol was noticed. The possible reasons for this contrary observation were proposed to be related to the amount of the produced water vapor during the sensing reactions assisted by the ZSM-5 nanoparticles. This provides a possible new strategy to improve the selectivity of the gas sensors. The effect of the humidity on the sensor response to formaldehyde was investigated and it was found the higher humidity would decrease the sensor response. A coating layer of the ZSM-5 nanoparticles on top of the SnO2-ZSM-5-sensing film was thus applied to further improve the sensitivity and selectivity of the sensor through the strong adsorption ability to polar gases and the “filtering effect” by the pores of ZSM-5.

One of the major challenges in the treatment of hearing loss is the low efficacy of therapeutic candidates. To achieve the optimum drug efficacy, we designed a novel peptide (D-Arg-Dmt-Arg-Phe-NH2)-mediated mitochondrial targeted delivery nanosystem for a promising candidate, geranylgeranylacetone (GGA). The zebrafish lateral line system, a robust model for mammalian hair cells, was used to identify the efficacy against gentamicin, a well-known ototoxic agent. The nanosystem facilitated lysosomal escape and mitochondrial accumulation, and thus conferred superior protective efficacy against a wide range of gentamicin compared with unmodified NPs and free drugs. Meanwhile, peptides-modified NPs internalized hair cells via both of dynamin-dependent and independent routes, following a classic endocytic or autophagy pathway. Although extracellular action via MET channels, the primary protective mechanism underlying peptides-modified NPs was revealed due to their intracellular interaction. Thus, our nanoplatform provided a general strategy to enhance the clinical efficacy of a broad range of drugs in the treatment of hearing loss.