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We report a mechanical metamaterial-like behavior as a function of the micro/nanostructure of otherwise chemically identical aliphatic polyurea aerogels. Transmissibility varies dramatically with frequency in these aerogels. Broadband vibration mitigation is provided at low frequencies (500-1000 Hz) through self-assembly of locally resonant metastructures wherein polyurea microspheres are embedded in a polyurea web-like network. A micromechanical constitutive model based on a discrete element method is established to explain the vibration mitigation mechanism. Simulations confirm the metamaterial-like behavior with a negative dynamic material stiffness for the micro-metastructured aerogels in a much wider frequency range than the majority of previously reported locally resonant metamaterials.

The utilization of solid electrolyte (SE) to suppress lithium (Li) dendrites is promising but still far from satisfactory due to the inhomogeneous Li plating/stripping. Here, we demonstrated a novel strategy to inhibit Li dendrites via regulating Li-ion flux in SE by using vertically aligned channels. The ion-insulating walls facilitated uniform distribution of Li-ion flux through the channels, leading to a homogeneous Li deposition, thus alleviating Li dendrite formation. As a result, symmetric cells with this SE exhibited excellent long-term stability (1000 ​h) against Li metal. In addition, Li4Ti5O12 (LTO)/Li cell with the developed SE achieved good battery performance over 100 cycles. The mechanism for dendrite suppression was further investigated by phase-field simulation. This work provides a novel strategy by manipulating uniform Li-ion flux to fabricate SE to inhibit Li dendrites and facilitates the development of high-performance rechargeable Li batteries.

Lithium (Li) dendrite growth poses serious challenges for the development of Li metal batteries. Replacing liquid electrolyte with solid composite electrolyte embedded with nanofiller additives can...

Tilapia (Oreochromis nilotica L.) skin collagen is a meritorious commercial resource to be exploited. The purpose of this study was to obtain, evaluate, and characterize tilapia skin collagen-derived antioxidant hydrolysates (TSCP). AAPH-induced erythrocyte hemolysis assay and antifatigue test in mice were implemented. It was indicated that TSCP treatment at 1 mg mL-1 could effectively attenuate AAPH-induced erythrocyte hemolysis rate from 56.35 ± 2.46% to 18.78 ± 2.48% (p < 0.01). A 2.5 mg/(10 g d) dose of TSCP intragastric administration could observably prolong the exhaustive swimming time of the loaded mice and its mechanism was multiple, including the decrease in the levels of serum lactic acid, serum urea nitrogen, and creatine kinase activity, thus improving the contents of liver and muscle glycogen and endogenous SOD activity. Five oligopeptides from the antioxidant fraction were identified as Gly-Hyp, Glu-Asp, Asp-Hyp-Gly, Glu-Pro-Pro-Phe, and Lys-Pro-Phe-Gly-Ser-Gly-Ala-Thr and then synthesized. Among them, the octapeptide exhibited the strongest antioxidant capacity. Therefore, tilapia skin-derived collagen is a meritorious edible resource for producing commercial functional foods, thus helping to scavenge radicals, protecting erythrocytes, and further resisting fatigue.

Biofilm formation in the production of fermented vegetable might impact its quality and safety. In this study, physicochemical and microbial properties, volatile and aroma-active compounds between PRPs without biofilm (NPRP) and with biofilm (FPRP) were investigated by gas chromatography-mass spectrometry, gas chromatography-olfactometry, aroma extract dilution analysis, and spiking tests. The pH and titratable acidity were 3.66 ± 0.00 and 0.47 ± 0.08 g/100 g lactic acid in NPRP and 3.48 ± 0.01 and 0.87 ± 0.10 g/100 g lactic acid in FPRP, respectively. The nitrite level of the two PRPs was 1.87–1.92 mg kg−1, which was below the limited value (20 mg kg−1) of fermented vegetables regulated by the GB2760-2017. FPRP had relatively higher microbial and yeast numbers than NPRP, three common pathogens, namely, Salmonella spp., Staphylococcus aureus, and Shigella spp. were not detected. A total of 70 and 151 aroma compounds were detected in NPRP and FPRP, respectively, including 13 classes of compounds. The dominant aroma attributes of FPRP were sour, floral, mushroom-like, green, and smoky, while NPRP exhibits a mushroom-like flavor. Acetic acid, ethanol, α-terpineol, (E)-2-nonenal, 2-heptanol, phenylethyl alcohol, and linalool were potent key aroma-active compounds in NPRP and FPRP. Results of spiking tests showed that the addition of each substance not only increased its own odour, but also had significant effects on other smells. FPRP displayed richer varieties and contents of aroma profile than NPRP. However, some compounds, such as 4-ethylguaiacol and 4-vinylguaiacol, which were only detected in FPRP, had negative roles on the aroma attributes.

Local liquid film behavior of annular flow on rod bundle geometry is vital for accurate prediction of dryout. This paper is the first part of a two-part study concerning measurement and analysis of local liquid film behavior of annular flow on rod bundle geometry. In this paper, air-water annular flow experiments have been performed at different gas and liquid superficial velocity conditions in a 3 × 3 simulating PWR fuel rod-bundle test-section, and a conductivity-based technique is developed to measure the local dynamical liquid film thickness. Large amplitude disturbance waves appear at all low liquid phase superficial velocity conditions through down-burst mechanism caused by the highly turbulent gas flow and strong inter-subchannel interaction. Wave shapes do not change drastically by the variation of superficial liquid velocity since liquid flow tends to fill out the rod bundle corner due to the nature of annular flow. For disturbance wave dominating the film flow case, secondary flow in subchannel produces a circumferential force to shear off the liquid film, and the liquid droplets are redistributed, resulting in the liquid film thickness for the central region being thicker than that of gap region. Cross-correlation analysis indicates that gap and central regions are in possession of circumferential coherent wave structure with the same interfacial velocity, and the wave position for the central region is a little ahead of that for gap region since a higher wave has a longer leeward and upwind faces. The current study on local liquid film behaviors for rod bundle and the possible mechanisms that causing the discrepancies in local liquid film structures can be further used for the mechanism model development for the liquid film flow on the rod bundle. Part II of this study will introduce a mechanism model as an alternative approach to local liquid film thickness prediction for annular flow in rod bundle geometry.

In order to study the trajectory characteristics of supercavitating vehicle in free motion, a series of experiments were carried out on an unpowered vehicle under ventilation and non-ventilation conditions respectively. High-pressure gas was utilized to launch the vehicle. The flow pattern in free motion was captured by using a high-speed video camera, the variations in the motion parameters and the cavity pressure were simultaneously recorded by using the internal measuring system. The measured data under ventilation and non-ventilation conditions were analyzed in detail, giving the effect of the ventilation on the motion of the vehicle. The experimental results show that the cavitation number fluctuates around a certain value under the influence of both velocity of the vehicle and the ventilation flow rate, keeping the vehicle to stably move in the supercavitating state. Under non-ventilation condition, the vehicle moves stably at the state of supercavitating and double-cavity closed on at the cylindrical section of the vehicle. But the motion turns into instable when the cavity is closed at the shoulder of the vehicle. Therefore, to reduce the cavitation number by ventilation is beneficial to maintaining the stability of the vehicle.

The bioreduction of aged nanoscale zero valent iron (NZVI) by Shewanella putrefaciens CN32 (CN32) in the presence of different biochar materials was conducted to understand how biochars mediated the activation of aged NZVI to enhance the removal efficiency of contaminants. The results indicated that the prepared biochars contained different oxygen-containing functional groups (such as O C O, COOH, C O, C O, C C, C H and C C). The biochars significantly enhance electron transfer from CN32 to aged NZVI, thus accelerating reductive dechlorination of Pentachlorophenol (PCP). The maximum PCP degradation rate (kmax) was 2.45 mg·L−1·d−1, which was 2.6 times greater than that of the biochar-free control (0.94 mg·L−1·d−1). The intermediates of phenol were detected after 30 days, likely indicating that reductive dechlorination was the dechlorination pathway of PCP. The X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis showed that vivianite, as a secondary mineral, was formed during the bioreduction aged NZVI-BC600 (Biochar prepared at 600 °C with NZVI activation) by CN32. Vivianite was formed mainly through the reaction of Fe(II) and PO43−. The combined electrochemical and electron paramagnetic resonance analysis might suggest that biochar associated semiquinone radical (C O) were likely involved in the bioreduction of aged NZVI. This study provided some theoretical support for further research on biochar mediated bioreduction activation of aged NZVI to enhance the degradation of contaminants.

Neutrase-hydrolysates hydrolyzed from mulberry leaf proteins were separated by ion exchange chromatography, gel filtration chromatography, and semipreparative reverse-phase HPLC. Purified fractions were analyzed for their radical scavenging activity, hemolysis inhibition ability, and cellular antioxidant activity (CAA). Three new antioxidant peptides, P1 (SVL, 317 Da), P2 (EAVQ, 445 Da), and P3 (RDY, 452 Da), were obtained from the most active HPLC fraction (R1) and identified using UPLC-QTOF-MS. These three peptides were then synthesized, and their antioxidant activities were analyzed. P1 and P2 had no ability to inhibit hemolysis of erythrocytes but did show antioxidant activity on HepG2 cells. P3 showed the highest hemolysis inhibition ability (92%) and CAA value (2204 μM QE/100 g peptide). The Tyr residues at the C-terminal region play an important role in the antioxidant activity in P3. Thus, the natural peptide R1 and synthesized P3 could be used as antioxidants and might be promising components of functional foods.

G-quadruplex specific dyes are powerful tools for probing nucleic acid structures. Among nucleic acids, aptamers are of great interest, and widely exploited to construct versatile bioassays. Herein, based on G-quadruplex selective dye, thioflavin T (ThT), for probing the intrinsic structure of aptamers, we proposed a ratiometric fluorescence resonance energy transfer (FRET) aptasensor enabling robust and ultrafast detection of toxin. The binding of target ochratoxin A (OTA) would destruct the G-quadruplex structure of aptamer. It would lead to the detachment of ThT dye from aptamer which diminished the FRET effect between ThT and terminal-labeled dye, thus allowing quantification of OTA via FRET signals. The FRET aptasensor would confer an enhancement of 76.9% of signal to background ratio compared to the ThT-based non-FRET aptasensor. Remarkably, the FRET mechanism would eliminate the signal fluctuation resulted from varied probe concentration, thus benefiting the robustness of the assay. The aptasensor could achieve a detection of limit of 0.38 ng/mL for OTA detection. And the detection of OTA could be finished within 30 s. Besides, the assay was successful in analyzing OTA in coffee and oat samples with recoveries rate of 93.93%–107.59%. Therefore, G-quadruplex specific dye-based probing and FRET method would be a compelling design strategy for aptasensor, and may facilitate their practical application in food safety and environmental screening.

A gas chromatography-tandem mass spectrometry coupled to QuEchERS extraction method was developed for the determination of 7 volatile N-nitrosamines (VNAs) in Chinese Sichuan salted vegetables, and the method detection limit (MDL), method quantification limit (MQL), recovery and relative standard deviation (RSD) were determined. Furthermore, the VNA contents of 406 Sichuan salted vegetables were measured and discussed. The MDL of the 7 VNAs ranged from 0.02 to 0.15 ng/g, and their recoveies when spiked with 10 ng/g standards ranged from 91.5 to 106.1%. The within-day RSD and between-day RSD were 2.1–4.6% and 2.4–7.2%, respectively. These results indicate that the method developed was of good accuracy, repeatability and reproducibility. The mean content of total VNAs in the 406 Sichuan salted vegetables was 0.56 ng/g, and more than 95% of them (n = 386) were at low VNA content ( 0.05). The VNA with both the highest concentration and the highest occurrence frequency of ≥3 ng/g was N-nitrosopyrrolidine.

The drift-flux model is important for rod bundle two-phase flow analysis. A 5 × 5 rod bundles experiment has been performed under air-water two-phase flow conditions. The superficial liquid velocity ranges from 0.00 to 1.50 m/s while the superficial gas velocity ranges from 0.02 to 6.00 m/s. The void fraction has been measured by the impedance meter. Four typical drift-flux models developed for rod bundles have been compared with present data. By analyzing the experimental data and visualization, the distribution parameter may be influenced by the flow recirculation and turbulence significantly. In order to consider these two effects, a critical liquid velocity has been defined to determine which effect is dominant as the increase of liquid velocity, and a new critical void fraction correlation related to the flow-regime transition from cap-bubbly to cap-turbulent flow is incorporated to determine the distribution parameter. The new drift-flux model developed from existing models shows a good prediction capability.

In relation to the development of flow regime criteria for rod bundle geometry, this paper provides several experimental flow regime maps at different axial locations with simple and prototypic spacer grids, respectively. Experiments with vertical adiabatic air-water flow were conducted under an atmospheric pressure condition. The experiment facility was composed of 5 × 5 rod arranged on a square pitch in a square casing with 9.5 mm outside diameter and 12.6 mm pitch. The inlet superficial gas velocities range from 0.01 to 8.69 m/s, while inlet superficial liquid velocities range from 0.06 to 2.51 m/s. New flow regime maps were acquired at three axial locations of z/DH = 21.9, 58.4 and 107 through high-speed camera images. The experimental maps obtained were compared with the existing analytical models of flow regime transition criteria for vertical rod bundles. A reasonable agreement has been obtained between measured flow regime maps and models of the existing flow regime transition criteria for rod bundles at fully developed flow conditions. The different effects of two types of spacer grids on the flow regime transition were also discussed in this paper.

Hydroxy-sanshool compounds were extracted from the hydrodistillation residue of Z. bungeanum Maxim. pericarp (ZBM) and Z. armatum DC. pericarp (ZADC) by using ethanol–water extraction and extractions assisted with (i) enzymes, (ii) ultrasound, and (iii) enzymes and ultrasound. The yields of the hydroxy-sanshool extracts under these four extraction conditions were calculated and compared. The ultrasound-assisted enzymatic extraction was then optimized based on a Box–Behnken design. Furthermore, five hydroxy-sanshool compounds in the extracts were quantified and their pungent taste contribution value (PCV) was calculated. Oral sensory evaluation was finally performed. Compared with that of the hydroxy-sanshool extracted with ethanol–water, the yields of the samples from the extraction assisted with enzymes, ultrasound, and enzymes and ultrasound increased by 4.2–7.6%, 9.3–9.8%, and 21.5–26.2%, respectively. A maximum yield of 7.87% (w/w) was achieved by using ultrasound-assisted enzymatic extraction under the optimal conditions: 3.1% (w/w) amount of enzyme, an incubation temperature of 50.3 °C, and an ultrasound irradiation power of 207 W. The PCV of hydroxy-α-sanshool, hydroxy-β-sanshool, hydroxy-γ-sanshool, hydroxy-e-sanshool, and hydroxy-γ-isosanshool was 1153, 447, 461, 139, and 51 ml g−1 for the ZBM extract, respectively, while the PCV of these five hydroxyl-sanshools was 659 ml g−1, 575 ml g−1, not detected, 119 ml g−1, and not detected for the ZADC extract, respectively. Tingling and salivation were the main taste sensations of ZBM, whereas numbing and tingling sensations were dominant in ZADC.

The hydrogel formed by the directed self-assembled rhein molecules at an appropriate pH value for sustained drug release has been reported recently. Although the application in drug therapy has been experimentally verified, the research on the mechanism of the self-assembly by rhein is still incomplete. In this study, we provide a new insight of the pH-induced self-assembly mechanism employing the dissipative particle dynamics (DPD) as well as multiscale molecular simulations. It comes to the conclusion that protonated rheins incline to aggregate, so spherical, columnar, and membrane-shaped aggregated micelles can be observed with the mounting drug concentrations. However, the thermodynamic solubility of these structures is relatively weak, which ultimately causes the system to precipitate. While, driven by the better hydrophilicity and charge effect of the deprotonated rheins, the self-assembly conformation of deprotonated rheins grows through a sphere, wormlike, long wormlike manner, resulting in a host of discontinuous and highly dispersive morphologies. Those structures, having good thermodynamic solubility though, cannot provide the required mechanical properties, thus the rhein system can only exist in the aqueous solution state. Only when the value of pH is moderate (the corresponding degree of deprotonation is 36 %-60 %), could a continuous network self-assembled structure be obtained, leading to the formation of hydrogel to meet the clinical requirements.

Drift-flux model has been one of the most popular models predicting two phase flow parameters in nuclear reactor and other industrial equipment since proposed. Most of researches are based on the void fraction measurement on the whole cross-section of the void fraction, which is under the influence of casing tube and might be unfit for sub-channel. Therefore, experiments have been performed to measure the void fraction in sub-channels with the newly designed impedance void meter, based on which the existing drift-flux correlations have been evaluated. However, few correlations have good performance in bubbly and cap bubbly flow. In order to improve the accuracy and consider the physical significance, the new correlation of distribution parameter is proposed by adopting Julia’s drift velocity correlation. The proposed correlation could predict the present data, Yang’s data and Clark’s data with the mean relative error of 13.96%, 16.23% and 24.9% respectively. Furthermore, the L/D effect on distribution parameter has been analyzed with different spacer grids. The mixing vane spacer grid (MVSG) results in a larger value of distribution parameter than simplified spacer grid in low void fraction region for the stronger recirculating flow.

Immobilizing nanoscale zero-valent iron (NZVI) particles on silica-based supports is an effective way to overcome the NZVI aggregation. The pH value and calcium hardness can change the aggregation kinetics and alter the stability of the suspensions of NZVI-silica based materials, thus change the reactivity of these NZVI-silica based materials to remove chlorinated aliphatic hydrocarbons (CAHs). The removal of CAHs by these NZVI-silica based materials includes adsorption by silica based supports and degradation by NZVI particles. Using 1,1,1-TCA and mesoporous hydrated silica (mHS) as model chlorinated aliphatic hydrocarbon (CAH) and silica based support, the effects of pH value and Ca2+ concentration on both the adsorption and adsorption-degradation processes of CAHs by NZVI-silica based materials were studied. The structural and textural features, suspension stability, particle size distribution, and Zeta potential of the materials under various conditions were characterized by different techniques. Both decreasing initial pH value and increasing Ca2+ concentration can reduce the Zeta potential of mHS and lead to the aggregation of mHS particles, thus inhibiting the removal of 1,1,1-TCA via adsorption by mHS through decreasing the number of sites for adsorption. Low initial pH value can accelerate the corrosion of NZVI core and remove the passivation layer, thus promoting the removal of 1,1,1-TCA via adsorption-degradation by NZVI@mHS. Ca2+ can decrease the sites for adsorption and form precipitates which can block mesoporous channels, thus hinder the 1,1,1-TCA removal via adsorption-degradation by NZVI@mHS.

In order to predict the thermal–hydraulic parameters in nuclear reactor accurately, it is essential to reveal the phase distribution characteristics, the mechanisms of phase interactions and the effects of the mixing vane spacer grid (MVSG) in rod bundles, based on which the drift-flux model and interfacial area transport equation could be developed further. The profiles of local two phase flow parameters could give an insight into these phenomena. Therefore, the adiabatic air–water upward two-phase flow experiments are performed to measure local parameters in 5 × 5 rod bundles with mixing vane spacer grids (MVSGs) under different bubbly flow conditions. The miniaturized four-sensor conductivity probe (MFSCP) has been developed to measure local two-phase flow parameters, such as void fraction, interfacial area concentration (IAC), bubble velocity and bubble chord length. The detail local parameters are measured and analyzed in the bubbly flow. Typical wall peaks for void fraction are identified and the bubble velocity profiles have a reverse phase position with void fraction profiles. The mixing vane spacer grid (MVSG) plays an important role in phase distribution in rod bundles: the skewed peaks of void fraction is associated with the direction of mixing vanes; a larger value of area-averaged void fraction is induced at the downstream of MVSG; compared with other factors, the MVSG plays a leading role in interfacial area transportation. Moreover, the dissipation length of MVSG is less than 19.4 L/D for current bubbly flow conditions.

For the modeling of the interfacial structure characteristics, an experiment of vertical adiabatic air-water flow has been conducted under an atmosphere pressure condition. The experimental facility is composed of 5 × 5 rods arranged on a square pitch in a square casing with 9.5 mm outside rod diameter and 12.6 mm pitch, simulating a prototypic rod bundle in nuclear reactors. The miniaturized four-sensor conductivity probe has been developed to allow for the experimental measurement in the small flow channel. Extensive data are acquired for one-dimensional flow parameters including axial development of void fraction, interfacial area concentration and gas velocity. The effect of a prototypic spacer grids with mixing vanes on the flow structure has been discussed at various flow conditions based on the experimental data. Two competing effects, “swirling effect” and “bubble breaker effect”, are identified. The effect vanishes out within a short distance from the space grid. A drift-flux correlation is developed for predicting void fraction of adiabatic bubbly two-phase flow in a vertical rod bundle. Existing interfacial area correlations are tested and Hibiki-Ishii correlation (2002b) is recommended as most accurate correlation to predict the interfacial area concentration. It is expected that the newly obtained data in the 5 × 5 rod bundle is useful for developing the interfacial area transport equation and benchmarking a computational code.

The accurate prediction of thermal-hydraulic parameters is based on the flow regime maps for rod bundle, which is important for the safety of nuclear reactor. An air-water two phase flow experiment has been performed to study the sub-channel flow regime (SCFR) maps in 5 × 5 rod bundles section with two distinct spacer grids, including simplified spacer grid (SSG) and mixing vane spacer grid (MVSG). To obtain the objective SCFR maps in rod bundles, a sub-channel impedance void meter is newly developed to measure the time series void fraction in sub-channels. Besides, the random forest clustering algorithm has been adopted to identify the sub-channel flow regimes objectively based on a training sample and 13 selected feature values of time series void fraction. The feature values include mean value, standard deviation value, sample entropy value and 10 proportion values. In this way, the objective sub-channel flow regime maps are obtained at four different locations with different spacer grids. Distinct features have been observed for different SCFRs. As for the SCFR transitions in different sub-channels over the same cross-section, almost all of them arise in the inner sub-channel firstly for the effect of casing tube. Moreover, the dissipation length of spacer grid is larger than 19.5 L/D. In the influencing region of spacer grid, the transition from cap bubbly to cap turbulent flow occurs in the corner sub-channel at 19.5 L/D downstream of spacer grid firstly and then at 6.8 L/D for low liquid velocity, while firstly occurs at 6.8 L/D for high liquid velocity. The magnitude of the spacer grid effect on SCFR transition depends on the superficial liquid and gas velocity, as well as the structure of spacer grid for current flow conditions. Only Liu and Hibiki’s model is applicable for the transition from bubbly to cap bubbly flow in sub-channel. Therefore, new transition models or correlations should be developed for other sub-channel flow regime transitions.

Nanoscale zero-valent iron@mesoporous hydrated silica core-shell particles (NZVI@mHS CSP) with improved dispersibility, transportability and dechlorination strength were successfully synthesized and tested for the removal of chlorinated aliphatic hydrocarbons from groundwater. The structural, electronic and textural features of the NZVI@mHS CSP were characterized by different techniques. The NZVI@mHS CSP depicted a specific surface area of 71 m2·g−1, significantly higher, compare to NZVI (12 m2·g−1), with a mesoporous network due to the formation of a hydrated silica shell surrounding the NZVI particle. NZVI@mHS CSP showed an enhanced transportability in sand column compared with NZVI, related to the suspension stability, small aggregated particle size (

The research of two-phase flow is very important for the safe operation of nuclear reactor. However, measurement method is a limitation for the experiment investigation of the two-phase flow in rod bundle channel. To measure the average void fraction of a sub-channel in rod bundle geometry, a new impedance meter is developed. The sensor of the impedance meter is composed of twelve electrodes. Due to the special architecture of rod bundle channel, the sensitivity and linearity of the impedance meter are different for different combination schemes of electrodes. To find the best scheme for the impedance meter, some combination schemes are researched based on the distribution of electric field. Simulation and experiment methods are used to study the schemes. A best scheme is given at last, and an experiment is designed to prove the result.

The phase distribution in rod bundle channel was associated with the heat transfer coefficient, flow resistance and critical heat flux, which was of great significance for the design and safe operation of nuclear reactor and steam generator. In order to clarify the phase distribution characteristics and reveal the effect of mixing vane spacer grid (MVSG) in two-group air-water flow in rod bundle channel, the adiabatic upward air-water two-phase flow experiments were conducted in 5 × 5 rod bundles with MVSGs and the detailed local two-phase flow parameters were acquired with miniaturized four-sensor conductivity probe (MFSCP). Some interesting phenomena were reported: Group I and II void fraction profiles showed the core-peak features; Group I void fraction almost stayed at the region from 0.2 to 0.3 for two-group air-water flow at current flow conditions; the dissipation length of MVSG was larger than 32.1 L/D at current two-group flow conditions; and the influencing region of MVSG was divided into at least three regions along the axial direction with the flow development for current flow conditions.

Soybean (Glycine max) is a facultative short-day plant with a sensitive photoperiod perception and reaction system, which allows it to adjust its physiological state and gene regulatory networks to seasonal and diurnal changes in environmental conditions. In the past few decades, soybean cultivation has spread from East Asia to areas throughout the world. Biologists and breeders must now confront the challenge of understanding the molecular mechanism of soybean photoperiodism and improving agronomic traits to enable this important crop to adapt to geographical and environmental changes. In this review, we summarize the genetic regulatory network underlying photoperiodic responses in soybean. Genomic and genetic studies have revealed that the circadian clock, in conjunction with the light perception pathways, regulates photoperiodic flowering. Here, we provide an annotated list of 844 candidate flowering genes in soybean, with their putative biological functions. Many photoperiod-related genes have been intensively selected during domestication and crop improvement. Finally, we describe recent progress in engineering photoperiod-responsive genes for improving agronomic traits to enhance geographic adaptation in soybean, as well as future prospects for research on soybean photoperiodic responses.

The fine-grained heat-affected zone (FGHAZ) specimens for P92 steel weld were produced by welding thermal simulator, then the simulated specimens were aged at 923 K for 0∼5000 h. The Laves phase parameters of FGHAZ were measured using SEM-back-scattered electron, and a two-dimensional (2D) precipitate/matrix model was used to calculate the stress-strain concentration at Laves phase/matrix interface by ANSYS. The results indicate that the maximum precipitated quantity of Laves phase in both FGHAZ and base metal (BM) is around 1.0%; however, the time to the saturated value is about 500 h shorter in the FGHAZ than in the BM, meanwhile. In fact, the differences in precipitation and coarsening of Laves phase between the FGHAZ and BM are closely correlated to the grain size. Furthermore, the matrix of FGHAZ is softened due to its polygonal sub-grains with low dislocation densities replacing the martensitic lath structure. The concentration of stress-strain at the Laves phase/matrix interface is larger in the FGHAZ than in BM, resulting from its softened matrix and coarser Laves phase, which contributes to the formation of creep voids on grain boundaries. Among these two factors, the softening of matrix has more significant influence on the formation of creep voids over the coarsening of Laves phase.

The current paper investigates an upward two-phase flow of air-water mixture in vertical narrow rectangular channels with two different cross-sectional dimensions of 25 × 5 mm and 25 × 2 mm respectively by using VOF (Volume of Fluid) model. To facilitate the simulations of different flow patterns, a simple and practical inlet condition, which is validated by experimental results, is employed. In the VOF model, the inlet condition will make the gas phase to be air layers, and due to the entrainment effect, the layers would coalescent and break up to small bubbles. The simulation results reveal that the main flow patterns of the two-phase flow in narrow channels are bubbly flow, slug flow, churn-turbulent flow and annular flow, and the void fraction distributions of those flow patterns are quite different. The void fraction of bubbly flow is below 0.3, which is consistent with published literatures. As the Taylor bubbles are located at the center of the flow channel and the slug flow is intermittent, the void fraction of slug flow is more evenly distributed in the center. The flow pattern map has been drafted under various air–water superficial velocities. The central region of the annular flow is gas core entrained liquid droplets, thus the void fraction is almost constant in the central region. The two-phase flow pattern map of a vertical rectangular channel shows that the range of annular flow in the channel is larger, while the scopes of slug flow and bubbly flow in the channel are smaller in comparison with the flow pattern map of tube. In addition, the transitional boundaries between flow patterns occur at smaller gas velocity than those in the tube. While compared the 2 mm gap rectangular channel with the 5 mm ones, it is found that with the gap size reducing, the flow pattern transition boundary shifts to the left.

Two reported Ir(iii) complexes 1a and 1b containing oxazoline and imidazoline in ancillary ligand, respectively, were investigated by DFT/TD-DFT method. In order to obtain full-color display materials, we designed a group of Ir(iii) complexes 2a-3d based on 1a, which exhibits higher quantum efficiency in phosphorescence, by introducing electron-donating/electron-withdrawing moieties to different positions of the ancillary ligand to adjust emission color. In addition to calculating the radiation rate and analyzing its determining factors, we also estimated nonradiative ability by evaluating the spin-orbit coupling matrix element between the ground state (S0) and the lowest triplet state (T1) as well as the reorganization energy from T1 to S0 to estimate quantum efficiency more accurately. In particular, an in-depth analysis on the contribution of each vibration mode to reorganization energy helped us to identify the effect of substituents on the nonradiative process. Besides, charge injection/transfer properties and energy relation of the states related to exciton quenching via the triplet metal-centered state were also examined, which provide an estimation on the OLED performance of our designed complexes. Overall, we expect 2b and 3c to be more efficient blue-emitting emitters than 1a and 3a and 3b to be efficient green and red emitters, respectively.

The ability to manipulate domains underpins function in applications of ferroelectrics. While there have been demonstrations of controlled nanoscale manipulation of domain structures to drive emergent properties, such approaches lack an internal feedback loop required for automatic manipulation. Here, using a deep sequence-to-sequence autoencoder we automate the extraction of latent features of nanoscale ferroelectric switching from piezoresponse force spectroscopy of tensile-strained PbZr0.2Ti0.8O3 with a hierarchical domain structure. We identify characteristic behavior in the piezoresponse and cantilever resonance hysteresis loops, which allows for the classification and quantification of nanoscale-switching mechanisms. Specifically, we identify elastic hardening events which are associated with the nucleation and growth of charged domain walls. This work demonstrates the efficacy of unsupervised neural networks in learning features of a material’s physical response from nanoscale multichannel hyperspectral imagery and provides new capabilities in leveraging in operando spectroscopies that could enable the automated manipulation of nanoscale structures in materials., The scale and dimensionality of imaging data means information is commonly overlooked. Here, using recurrent neural networks we understand temporal dependencies in hyperspectral imagery, enabling the observation of differences in ferroelectric switching mechanisms in PbZr0.2Ti0.8O3 thin films due to formation of charged domain walls.

Cyclo[8]pyrrole (CP) was prepared and its UV/vis spectral and optical limiting properties for ns light pulse were investigated with Z-scan technical. Our experiments show that CP has good solubility in organic solvents, and its Q band absorption shows an obvious red shift to the NIR region at about 1100 nm compared with normal porphyrin. Studies on transient absorption spectra, photophysical parameters and optical limiting properties indicate that the compound exhibits good optical limiting performance under variable conditions. Briefly, it shows a reverse saturable absorber with the limiting threshold of 1.8 J cm−2 at 1064 nm in dichloromethane; interestingly, it displays limiting properties at both 532 nm and 1064 nm after treatment with NaOH.

A novel borondifluoride curcuminoid complex TB showing an AIE effect is designed and prepared. The photophysical properties were investigated by tuning the TICT and AIE state in various solutions. In particular, the TB loaded nanoparticles acted as an excellent reagent for cellular imaging.

Spatially resolved time and voltage-dependent polarization dynamics in PbTiO3 thin films is explored using dynamic piezoresponse force microscopy (D-PFM) in conjunction with interferometric displacement sensing. This approach gives rise to 4D data sets containing information on bias-dependent relaxation dynamics at each spatial location without long-range electrostatic artifacts. To interpret these data sets in the absence of defined physical models, we employ a non-negative tensor factorization method which clearly presents the data as a product of simple behaviors allowing for direct physics interpretation. Correspondingly, we perform phase-field modeling finding the existence of ‘hard’ and ‘soft’ domain wall edges. This approach can be extended to other multidimensional spectroscopies for which even exploratory data analysis leads to unsatisfactory results due to many components in the decomposition.

Reduced glutathione (GSH) and some food-derived phenolic acids are welcome as natural antioxidants, but their synergistic antioxidant effect is unknown. The purpose of this study was to screen out the combination of GSH and the phenolic acid with synergistic antioxidant effect, improve their coexistence and protect the activity. Antioxidant evaluation systems including ABTS, DPPH, ORAC and reducing power assays were implemented, and dynamic light scattering and transmission electron microscopy analysis were carried out. Caffeic acid (CA) and GSH exhibited significant synergistic effect via electron transfer when the concentration ratio was 1:5. This combination was well embedded into chitosan-coated liposomes, which consist of evenly distributed and uniformly spherical microparticles, and its average particle size was 247.63 nm with polymer dispersity index of 0.29 and zeta potential of 57.73 mV. The encapsulation efficiencies of GSH and CA were 61.32% and 68.92%, respectively. The successfully prepared microparticles showed higher markedly antioxidant activity than the simple mixture and liposomes in 10-week storage. Therefore, co-encapsulation of GSH and CA using chitosan-coated liposomes is a potential approach to prepare natural potent antioxidant in food manufacture.

This paper presents the experimental results and analyses of the friction and local pressure loss coefficient of a 5 × 5 rod bundle with spacer grid. Based on the experimental data, friction and local pressure loss models were assessed and the role of spacer grid was discussed. The results showed that Cheng and Todreas model could predict bare rod friction loss well, and Chun model applied for high Re but would severely underestimate grid local loss for small Re. For two-phase condition, a universal correlation was proposed for bare rod two-phase friction multiplier, and it was found that all existing models cannot predict grid local loss multiplier very well. High prediction accuracy could be obtained by combining homogenous flow model, the liquid-mixture density ratio and a modification factor as a function of the grid parameter e (axial projected area of grid strip to flow area) and void fraction.

The protective shell plays an important role in preventing the aircraft from harmful environment impact. When it becomes an irregular body falling into the water, its motion is hard to predict. In this paper, firstly, a semi-cylindrical shell is taken as an example. Subsequently, the dynamics modeling of the irregular body is established, and the dynamics equations and the kinematics equations describing the underwater falling motion of the irregular body are presented, respectively. Finally, simulation is carried out to predict the falling process and analyze the typical trajectory of the underwater falling motion of the irregular body.

Agrobacterium tumefaciens can genetically transform various eukaryotic cells because of the presence of a resident tumor-inducing (Ti) plasmid. During infection, a defined region of the Ti plasmid, transfer DNA (T-DNA), is transferred from bacteria into plant cells and causes plant cells to abnormally synthesize auxin and cytokinin, which results in crown gall disease. T-DNA and several virulence (Vir) proteins are secreted through a type IV secretion system (T4SS) composed of T-pilus and a transmembrane protein complex. Three members of Arabidopsis reticulon-like B (RTNLB) proteins, RTNLB1, 2, and 4, interact with VirB2, the major component of T-pilus. Here, we have identified that other RTNLB proteins, RTNLB3 and 8, interact with VirB2 in vitro. Root-based A. tumefaciens transformation assays with Arabidopsis rtnlb3, or rtnlb5-10 single mutants showed that the rtnlb8 mutant was resistant to A. tumefaciens infection. In addition, rtnlb3 and rtnlb8 mutants showed reduced transient transformation efficiency in seedlings. RTNLB3- or 8 overexpression transgenic plants showed increased susceptibility to A. tumefaciens and Pseudomonas syringae infection. RTNLB1-4 and 8 transcript levels differed in roots, rosette leaves, cauline leaves, inflorescence, flowers, and siliques of wild-type plants. Taken together, RTNLB3 and 8 may participate in A. tumefaciens infection but may have different roles in plants.

A novel microbial procedure was proposed for diosgenin production from Dioscorea zingiberensis C.H. Wright (DZW) tubers via employing Aspergillus awamori for the first time. The optimal conditions of fermenter cultivation were established as inoculation dosage of 8%, fermentation temperature of 30 °C, cultivation time of 8 days, initial pH of 7.0 and a stirring rate of 180 rpm when the converted diosgenin content reached a peak value of 74.26 ± 3.23 mg/g substrate. The product was purified by silica gel column and then confirmed as diosgenin (purity: 96.9 ± 2.42%) by nuclear magnetic resonance (NMR). Compared with traditional acid hydrolysis, this new process generated indeed less wastewater with lower chemical oxygen demand (COD) reduced to 500 mg/L from 10,000 mg/L and absence of acid and alkali. This research provided definitely an environmental and high-efficiency microbial technology for diosgenin production.

In this work, the ordered nanoporous arrays of Au and Pt films are fabricated using anodized aluminum oxide (AAO) template based on the sputtering method. The presented synthetic strategy is scalable to large area by incorporating the deposition of a thin layer of Au or Pt. In addition, the grain size of Au and Pt nanoporous films is controlled with sputtering time. The thorough study of electrical transport properties for these metal films enables us to infer the nanoporous film morphology, and the evolution of the grain size with the change of sputtering time. In fact, the different physical behaviors are observed to occur in these metal films. The negative temperature coefficient of resistance (TCR) is visible for Pt nanoporous films, while Au nanoporous films show the positive TCR. With the increasing of sputtering time, the Pt grain size gradually becomes bigger, and the negative TCR properties weaken because the interface scattering of the electrons reduces. Therefore, the fabrication of metal nanoporous films with well-controlled physical properties might open new pathways for the growth of metal electrodes on AAO substrates for nanoelectronic devices.

Natural and nutrient substances for cardiovascular disease are promising and capture researchers' minds. Two kinds of novel bioactive peptides (high Fischer's ratio oligopeptides and anticoagulant peptides) were obtained from Whitmania pigra protein via enzymatic hydrolysis. An oligopeptide (MW

Department of Behavioural Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Pozna n, Poland; E-Mail: osiejuk@amu.edu.pl (T.S.O.) * Author to whom correspondence should be addressed; E-Mail: mike.johnson@marquette.edu; Tel.: +414-288-0631; Fax: +414-288-5579. Received: 1 September 2009; in revised form: 30 October 2009 / Accepted: 9 November 2009 / Published: 18 November 2009 Abstract : Using Hidden Markov Models (HMMs) as a recognition framework for automatic classification of animal vocalizations has a number of benefits, including the ability to handle duration variability through nonlinear time alignment, the ability to incorporate complex language or recognition constraints, and easy extendibility to continuous recognition and detection domains. In this work, we apply HMMs to several different species and bioacoustic tasks using generalized spectral features that can be easily adjusted across species and HMM network topologies suited to each task. This experimental work includes a simple call type classification task using one HMM per vocalization for repertoire analysis of Asian elephants, a language-constrained song recognition task using syllable models as base units for ortolan bunting vocalizations, and a stress stimulus differentiation task in poultry vocalizations using a non-sequential model via a one-state HMM with Gaussian mixtures. Results show strong performance across all

A novel and simple technique based on the light diffraction effect for visualization of low-frequency underwater acoustic waves (LFUAWs) in real time has been developed in this paper. A cylindrical object has been put on the surface of the water. A low-frequency underwater longitudinal wave can be generated into a water surface transversal capillary wave around the cylinder by our technique. Modulating the phase of a laser beam reflected from a water surface by surface acoustic waves (SAWs) realizes the acousto-optic effect. Then, a steady and visible diffraction pattern is experimentally observed. A physical model of the SAW is established to verify the feasibility of our technique. An analytical expression of wavelength, wave amplitude, and excitation frequency has been derived to study the physical properties of LFUAWs, and it explains the experimental phenomenon very well. As a result, the technique is effective, easy, and practical for visualizing LFUAWs and has significance for applications.