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UDP-glucose pyrophosphorylase (UGPase) is a key enzyme for polysaccharide synthesis, and its role in plants and bacteria is well established; however, its functions in unicellular microalgae remain ill-defined. Here, we perform bioinformatics, subcellular localization as well as in vitro and in vivo analyses to elucidate the functions of two UGPs (UGP1 and UGP2) in the model microalga Phaeodactylum tricornutum. Despite differences in amino acid sequence, substrate specificity, and subcellular localization between UGP1 and UGP2, both enzymes can efficiently increase the production of chrysolaminarin (Chrl) or lipids by regulating carbon flux distribution without impairing growth and photosynthesis in transgenic strains. Productivity evaluation indicate that UGP1 play a bigger role in regulating Chrl and lipid production than UGP2. In addition, UGP1 enhance antioxidant capacity, whereas UGP2 is involved in sulfoquinovosyldiacylglycerol (SQDG) synthesis in P. tricornutum. Taken together, the present results suggest that ideal microalgal strains can be developed for the industrial production of Chrl or lipids and lay the foundation for the development of methods to improve oxidative stress tolerance in diatoms. Both UDP-glucose pyrophorylases (UGP) UGP1 and UGP2 in microalgae are involved in lipid production and storage molecule regulation but differ in the type of lipids produced and effect on antioxidant capacity. [ABSTRACT FROM AUTHOR]

To study the effect of the Maillard reaction on the flavor and antioxidant activity of the Acetes chinensis hydrolysate after microwave heating, the Acetes chinensis hydrolysate glucose system was heated for 25 min using 100, 200, and 300 W power levels. The results showed that microwave accelerated browning and color change, the products had good flavor and taste characteristics at higher power levels, and the antioxidant activity of the products increased with increasing microwave power/time. These results indicate that the Maillard reaction under the microwave is an effective method of improving the flavor and antioxidant activity of protein hydrolysis products. [ABSTRACT FROM AUTHOR]

Background: Vitiligo was an autoimmune disease and some guidelines for the management of vitiligo encouraged the use of NB‐UVB combination therapies to enhance repigmentation. Objectives: To compare the effectiveness of current NB‐UVB combination regimen at the improvement in repigmentation through a systematic review and network meta‐analysis. Methods: We searched the electronic databases for randomized controlled trials related to NB‐UVB combination therapy for vitiligo till October 2022. STATA15.0 software was applied to carrying out data analysis. Results: A total of 28 eligible studies involving 1194 participants were enrolled in the analysis. The NMA results revealed that compared with NB‐UVB, carboxytherapy [OR = 32.35, 95% CI (1.79, 586.05)], Er: YAG laser+ topical 5% 5‐FU [OR = 10.74, 95% CI (4.05, 28.49)], needling/micro‐needling [OR = 3.42, 95% CI (1.18, 9.88)], betamethasone intramuscular injection [OR = 3.08, 95% CI (1.17, 8.13)], topical tacrolimus [OR = 2.54, 95% CI (1.30, 4.94)], and oral Chinese herbal medicine compound [OR = 2.51, 95% CI (1.40, 4.50)] integrated with NB‐UVB were more efficacious in excellent to complete repigmentation response rate (≥75%). Besides, NB‐UVB+ Er: YAG laser+ topical 5% 5‐FU [OR = 0.17, 95% CI (0.04, 0.67)] and NB‐UVB+ needling/micro‐needling [OR = 0.24, 95% CI (0.06, 0.88)] were less likely evaluated as ineffective repigmentation response (≤25%). Conclusions: All combination therapies ranked higher than NB‐UVB monotherapy in inducing successful repigmentation and avoiding failed treatment in patients with vitiligo. Comprehensive consideration, NB‐UVB+ Er: YAG laser+ topical 5% 5‐FU and NB‐UVB+ needling/microneedling would be the preferred therapeutic approaches. [ABSTRACT FROM AUTHOR]

Oleaginous microalgae have great application potential in the field of bioenergy. Increasing the biomass and lipid productivity of microalgae is beneficial to realize such potential. In this study, to explore the effect of overexpression of malic enzyme (ME) gene on the growth and lipid productivity in the diatom Phaeodactylum tricornutum, the transformant (overexpression of ME) was cultivated under nitrogen deprivation and normal condition. The biomass of the transformant was higher significantly than that of the wild type (WT) both under nitrogen deprivation and normal condition. This suggested that overexpression of malic enzyme gene stimulated the growth in P. tricornutum. The lipid content of the transformant under normal condition increased significantly compared with that of WT under nitrogen deprivation. The transformant strain exhibited further increase in lipid accumulation subjected to nitrogen deprivation. Upon nitrogen deprivation, lipid productivity of the transformant was significantly increased by 87.02% compared with that of the WT strain. These findings suggested that ME overexpression increased the production of NADPH, further stimulated the growth and lipid synthesis, resulting in enhancing lipid productivity in the transformant under nitrogen deprivation. This ME overexpression-nitrogen deprivation cultivation pattern provided a new route to enhance biodiesel production in microalgae. [ABSTRACT FROM AUTHOR]

The ferritic ductile cast iron, SiMo51, with graphite nodules and grain boundary carbides, was tested at 700°C with respect to creep, uniaxial strain and oxidation, investigating the internal damage evolution. Creep curves, with total lives of 65–339 days, show a short primary creep followed by predominantly tertiary creep displaying two stages. The first was associated with cavitation around carbides and nodules with a short initial effect from oxidation. The second was associated with the formation of cracks through linking of elongated voids. Misorientation maps demonstrate local dislocation activity during creep and tensile testing. Oxidation tests, between 15 min and 2 weeks, show that three oxide layers are formed and that an innermost precipitation zone of SiO2 is present in the initial stage. Elemental line scans, compared with thermodynamic calculations, suggest the layers are FeO with precipitates of SiO2 and/or Fe2SiO4, FeO without precipitates, and Fe2O3. [ABSTRACT FROM AUTHOR]

-MnS and α -MnS/rGO are synthesized by one-step hydrothermal method, using graphene oxide (GO), TAA (CH 3 CSNH 2) and MnCl 2 ·4H 2 O as reactants. We characterize the structure, size, morphology and absorption characteristics of samples. Results show that the size of α -MnS can be controlled and nanoparticles are attached on reduced graphene oxide (rGO). Nonlinear optical (NLO) properties of all samples are tested by the laser with wavelength of 532 nm and pulse width of 30 ps. Z-scan patterns display that α -MnS exhibits reverse saturation absorption, while composite shows enhanced saturated absorption. NLO properties of composites are better than that of α -MnS nanoparticles, implying that composites have potential applications in NLO devices. 1. α-MnS and α-MnS/rGO composite are successfully synthesized by one-step hydrothermal method. 2. The tunable sizes of α-MnS and α-MnS/rGO are obtained with high quality. 3. The nonlinear optical susceptibility of α-MnS/rGO is higher than that of α-MnS. [ABSTRACT FROM AUTHOR]

ZnSe/graphene composites are produced by chemical method, and the attachment of ZnSe nanocrystals on graphene nanosheets can be confirmed by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and UV-vis spectroscopy. The nonlinear optical properties are investigated at 532 nm by a picosecond laser Z-scan technique. It is found that the interaction between ZnSe and graphene enhances the optical nonlinearity of ZnSe/graphene composites than single ZnSe or graphene. The increase of ZnSe size further enhances the optical nonlinearity of ZnSe/graphene. [ABSTRACT FROM AUTHOR]

• Nanosecond pulsed laser welding of Al to Cu thin sheets was achieved. • Results of interfacial compounds formation at different spiral scan distances were clarified. • Highest lap shear force of 107.7 N was obtained at the spiral scan distance of 0.04 mm. • Three fracture modes produced at various spiral scan distances were clarified. The T2 Cu with a thickness of 0.2 mm and 6063 Al alloy with a thickness of 0.4 mm were joined via nanosecond pulsed laser welding in an inner spiral scanning mode. The lap configuration was Cu (upper)/Al (under). The influence of spiral scan distance (spiral distance for short) on the weld formation, microstructure and mechanical property was investigated. The results showed that circular holes and arc-shaped cracks formed on the weld surface at the spiral distance of 0.02 mm, and these defects disappeared at higher spiral distances. The tendency of porosity increased initially and decreased afterwards as the spiral distance increased. The interfacial morphology exhibited a wave-shaped structure at the spiral distance of 0.02 mm, and a continuous lump θ-CuAl 2 phase was produced at the interface. When the spiral distance was larger than 0.02 mm, the wave-shaped structure disappeared and V-shaped areas were generated due to the invasion of Al element into Cu base metal. α-Al and θ-CuAl 2 phases were possibly produced in these areas. The Cu-rich areas generated on the sidewall of the weld could cause the formation of θ-CuAl 2. According to the tensile-shear load results, the maximum shear force reached 107.7 N at the spiral distance of 0.04 mm. The satisfactory weld formation and larger effective bounding area contributed to the superior bonding strength. Three fracture modes (button pulling out failure, weld shear failure and interface failure) were observed in this study. [ABSTRACT FROM AUTHOR]

ZnS/MWCNTs composite materials with different concentrations of ZnS were prepared and their third-order nonlinear optical properties were studied through experiments and theoretical analysis. Structure and morphology characterizations of the ZnS/MWCNTs composite materials showed that ZnS quantum dots (QDs) were uniformly attached on the surface of MWCNTs. Third-order nonlinear optical properties of all the MWCNTs samples, ZnS QDs and ZnS/MWCNTs composite materials were measured by using Z-scan technique with a picosecond pulse laser. Experimental results showed that the composite materials always presented saturated absorption properties of MWCNTs and a negative nonlinear refraction effect of ZnS. [ABSTRACT FROM AUTHOR]

The potential use of microalgal biomass as a biofuel source has raised broad interest. Highly effective and economically feasible biomass generating techniques are essential to realize such potential. Flue gas from coal-fired power plants may serve as an inexpensive carbon source for microalgal culture, and it may also facilitate improvement of the environment once the gas is fixed in biomass. In this study, three strains of the genus Nannochloropsis (4-38, KA2 and 75B1) survived this type of culture and bloomed using flue gas from coal-fired power plants in 8000-L open raceway ponds. Lower temperatures and solar irradiation reduced the biomass yield and lipid productivities of these strains. Strain 4-38 performed better than the other two as it contained higher amounts of triacylglycerols and fatty acids, which are used for biodiesel production. Further optimization of the application of flue gas to microalgal culture should be undertaken. [ABSTRACT FROM AUTHOR]

Abstract: Recent studies have demonstrated that natural water that has 65% of the deuterium concentration depleted, can exhibit anti-tumor properties. However, the anti-tumor effects of DDW on various nasopharyngeal carcinoma (NPC) cells have not previously been reported. In the present study, NPC cell lines and normal preosteoblast MC3T3-E1 cells were grown in RPMI1640 media containing different deuterium concentrations (50–150ppm). The effects of DDW on the proliferation and migration of NPC and MC3T3-E1 cells were investigated using the MTT, plate colony formation, and Transwell assays, as well as Boyden chamber arrays, flow cytometry (FCM), western blot and immunofluorescence. We found that DDW was an effective inhibitor of NPC cell proliferation, plated colony formation, migration and invasion. In contrast, the growth of normal preosteoblast MC3T3-E1 cells was promoted when they were cultured in the presence of DDW. Cell cycle analysis revealed that DDW caused cell cycle arrest in the G1/S transition, reduced the number of cells in the S phase and significantly increased the population of cells in the G1 phase in NPC cells. Western blot analysis revealed that treatment with DDW significantly increased the expression of NADPH:quinone oxidoreductase-1 (NQO1), while immunofluorescence assay analysis revealed that treatment with DDW decreased the expression of PCNA and matrix metalloproteinase 9 (MMP9) in NPC cells. These results demonstrated that DDW is a novel, non-toxic adjuvant therapeutic agent that suppresses NPC cell proliferation, migration, and invasion by inducing the expression of NQO1 and causing cell cycle arrest, as well as decreasing PCNA and MMP9 expression. [Copyright &y& Elsevier]

Abstract: α-FeOOH nanorods (NRs) with diameters varying from 12nm to 25nm were prepared by colloid chemistry method, and their third-order nonlinear susceptibilities (χ (3)) were investigated by Z-scan technique. Both the real part and imaginary part of χ (3) increase with increasing the NRs’ size in the near resonant and transparency region. χ (3) of α-FeOOH NRs with the diameter of 25nm can reach 7.7×10−11 esu in the near resonant region, which is almost 16 times of that of the corresponding bulk. The quantum confinement effect and local field effect make the dominant contribution to the nonlinear enhancement. [Copyright &y& Elsevier]

Abstract: We have developed an apparatus for laser-cooling chromium atomic beams using one-dimensional optical molasses. The divergence of the atomic beam was reduced from 4.5mrad to 0.87mrad and the intensity of fluorescence was increased by 1.79 times with a 45mW laser power. [Copyright &y& Elsevier]

Coral bleaching, which is defined as the loss of s colour in corals due to the loss of their symbiotic algae c (commonly called zooxanthellae) or pigments or both, is oc- curring globally at increasing rates, and its harm becomes more and more serious during these two decades. The significance of these bleaching events to the health of coral reef ecosystems is extreme, as bleached corals exhibited high mortality, reduced fecundity and productivity and increased susceptibility to diseases. This decreased coral fitness is easily I to lead to reef degradation and ultimately to the breakdown of the coral reef ecosystems. Recently, the reasons leading to coral bleaching are thought to be as follows: too high or too low temperature, excess ultraviolet exposure, heavy metal pollution, cyanide poison and seasonal cycle. To date there has been little knowledge of whether mariculture can result in coral bleaching and which substance has the worst effect on corals. And no research was conducted on the effect of hypoxia on corals. To address these questions, effects of temperature, hypoxia, ammonia and nitrate on bleaching of three coral species were studied through examination of morphology and the measurement of the number of symbiotic algae of three coral species Acropora nobilis, Palythoa sp. and Alveopora verrilliana. Results showed that increase in temperature and decrease in dissolved oxygen could lead to increasing number of symbiotic algae and more serious bleaching. In addition, the concentration of 0.001 mmol/L ammonia or nitrate could increase significantly the expulsion of the symbiotic algae of the three coral species. Except for Acropora nobilis, the numbers of symbiotic algae of other two corals did not significantly increase with the increasing concentration of ammonia and nitrate. Furthermore, different hosts have different stress susceptibilities on coral bleaching. [ABSTRACT FROM AUTHOR]

In this research, Al/Cu lapped joints with a thickness of 0.2 mm were joined via nanosecond pulsed laser welding. The influence of laser scanning paths on the weld formation, microstructure and bonding strength was investigated. Sound weld formations were produced when the outer spiral laser scanning path was used. Porosities and cracks were easily formed in joints produced by concentric circle and straight laser scanning paths due to the interval duration between the neighboring welding processes. The interfacial morphology was a wave structure when the laser scanning paths were an outer spiral and concentric circle, and continuous interfacial intermetallic compound (IMC) was formed at the interface. θ–CuAl 2 was generated in the vicinity of the Cu substrate, while α-Al + θ–CuAl 2 was generated in the outer region and the weld seam. When a straight line laser scanning path was adopted, the wave structure disappeared. Discontinuous IMC and cracks were also produced at the interface. The tensile-shear load results indicated that the outer spiral laser scanning line was the most beneficial for the bonding strength of the joint and could reach up to 198 N. A satisfactory weld formation, the pinning effect due to the wave structure at the interface and continuous interfacial IMC all contributed to its highest bonding strength. [ABSTRACT FROM AUTHOR]

The austenitic ductile cast iron D5S, used for exhaust manifolds in heavy-duty truck engines, was creep tested at 750 °C in air under constant load with initial stresses of 18.5–50 MPa. Four of the specimens (20–50 MPa) were tested to rupture (22–5476 h) and the remaining one (18.5 MPa) was interrupted in the secondary creep regime after 6494 h. Secondary creep was generally predominant at lower stresses whereas primary and tertiary creep were predominant at higher stresses. The damage was characterized by various types of voids/creep cavities around the graphite nodules which were interlinked by shear cracks upon fracture. The results show that significant amounts of finely dispersed Cr 7 C 3 carbides, larger Fe 2 Ni 2 Si particles, and an unknown carbide precipitated during creep exposure. Dislocation substructures which had developed during creep were revealed through EBSD. [ABSTRACT FROM AUTHOR]

The austenitic cast steel HK30, used in exhaust manifolds of heavy-duty truck engines, was studied with respect to creep, creep damage, oxidation and precipitation at 750 °C in air. Even though creep clearly affects the lifetime of the manifolds, there are very few studies available on the topic. The results of the present study provide a basis for materials selection as well as creep data input to component lifetime simulations. In the present study, five specimens were subjected to constant loads resulting in creep rupture times between 1 and 94 days. The minimum creep rate follows Norton's creep law with a Norton parameter (n) of 8.9 and the logarithmic creep rupture time increases linearly with reduced stress. At low stresses secondary creep is predominant observing oxide intrusions from the specimen surface, precipitation of sigma and G-phases, creep cavitation at grain boundaries and weak dislocation networks. At high stresses direct transitions from primary to tertiary creep are observed as well as stronger dislocation networks, but no oxide intrusions, no precipitation, or cavitation are observed. The material has grains of cm size and intergranular fracture is predominant at all stress levels. The segregation of elements during solidification was studied by Scheil/Gulliver simulations and precipitations of sigma and G-phases in the last solidified regions were predicted using Thermo-Calc. [ABSTRACT FROM AUTHOR]

Complexes 1 and 2 are water-soluble and are pretty stable in dark. However, they exhibit good CO release ability upon exposure to UV and visible light. The CO releasing rate can be adjusted by the wavelength of irradiation light. Furthermore, they can inhibit the secretion of NO and TNF-α in LPS-stimulated RAW264.7 macrophages. • Complexes 1 and 2 exhibit good CO release ability upon exposure to UV/visible light. • The CO releasing rate depends on the wavelength of irradiation light. • Complexes 1 and 2 possess high water-solubility. • Complexes 1 and 2 can inhibit the secretion of NO and TNF-α. By reactions of MnBr(CO) 5 with 2,2′-bipyridyl-4,4′-dicarboxylic acid and 2,5-pyridinedicarboxylic acid, respectively, we obtained two new Mn-CORMs, [Mn(CO) 3 (H 2 O)(HBPDC)] (1) and [Mn(CO) 3 (CH 3 CN)(HPYDC)]·CH 3 CN (2). Complexes 1 and 2 are stable in the absence of light, but they exhibit good CO release ability upon exposure to UV and visible light (blue and green). The CO releasing rate depends on the wavelength of irradiation light, i.e., UV > blue > green, which may make them act as visible light regulated CORMs. It is noteworthy that complexes 1 and 2 possess high water-solubility. TD-DFT studies of complexes 1 and 2 reveal that the metal-to-ligand charge-transfer (MLCT) may be responsible for their CO releasing behaviors triggered by UV and visible light. The cellular viability and anti-inflammatory activities evaluation show that complexes 1 and 2 can inhibit the secretion of NO and TNF-α in LPS-stimulated RAW264.7 macrophages with fine biological compatibility and without apparent cytotoxicity. Furthermore, during the synthesis of complexes 1 and 2 , when the pH of solution is hinger than 7, complexes {[Mn(BPDC)]} n (1A) and [Mn(H 2 O) 2 (HPYDC) 2 ] (2A) are obtained. Complex 1A is a new 3D Mn-MOF and complex 2A is a zero-dimensional mononuclear compound, which are all without CO ligand. [ABSTRACT FROM AUTHOR]

CdSe-reduced graphene oxide (CdSe/RGO) composites were synthesized by a hydrothermal method. CdSe/RGO composites with different mass ratios were prepared. The structure and morphology of CdSe/RGO composites were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The synthesis of CdSe/RGO complexes was successfully demonstrated by Fourier infrared (FT-IR) and Raman spectra. CdSe nanoparticles in the CdSe/RGO composite were uniformly dispersed on the graphene surface. The study found that oxygen-containing functional groups such as hydroxyl (-OH) and carboxyl (-COOH) groups in graphene played a decisive role in the dispersion of CdSe. The third-order nonlinear optical properties of CdSe/RGO composites were measured by a single beam Z-scan technique. The experimental results showed that composites exhibited two-photon absorption and self-focusing nonlinear refraction properties. Additionally, the third-order nonlinear susceptibility of the composite material was obviously enhanced, which was mainly due to the good dispersion of CdSe nanoparticles on graphene. [ABSTRACT FROM AUTHOR]

Background Objectives Materials and methods Results Discussion Conclusion Erectile dysfunction has been associated with leisure sedentary behavior in several epidemiological and observational studies. However, the interpretation of these findings is difficult due to residual confounding or reverse causality.To explore the causal association between leisure sedentary behavior and erectile dysfunction, and to explore the underlying mechanism using Mendelian randomization.In the present study, publicly available large‐scale genome‐wide association studies of leisure sedentary behaviors (television watching, computer use, and driving), erectile dysfunction, sex hormones (total testosterone, bioactive testosterone, estradiol, follicle‐stimulating hormone, luteinizing hormone, prolactin, and sex hormone binding globulin), biomarkers of endothelial function (C reactive protein, E‐selectin, and matrix metalloproteinase 7), and psychiatric symptoms (depression and anxiety) were used to perform two‐sample Mendelian randomization analyses. The inverse variance weighting method was the main method used to estimate the association, and sensitivity analyses were also performed.A greater risk of erectile dysfunction was significantly associated with a higher genetic susceptibility to leisure computer usage (odds ratio = 3.57; 95% confidence interval = 1.78–7.16; p < 0.001). No evidence was obtained to suggest that watching television or driving for leisure increased the risk of erectile dysfunction. No association was found between computer use and depression, anxiety, C reactive protein, E‐selectin, matrix metalloproteinase 7, or other sex hormones, with the exception of follicle‐stimulating hormone levels (odds ratio = 0.29; 95% confidence interval = 0.12–0.69; p = 0.01). No indication of heterogeneity or pleiotropy was identified by sensitivity analysis.Extended computer usage for leisure raised the likelihood of developing erectile dysfunction, which may be associated to lower follicle‐stimulating hormone levels; however, the role of endothelial dysfunction and psychological disorders in the development of erectile dysfunction should not be underestimated. Moderate physical activity may help to correct the dysfunction.The present study offered substantial evidence for a positive causal association between computer use and the risk of erectile dysfunction. However, a definitive causal association needs to be established by further research. [ABSTRACT FROM AUTHOR]

Mg(Ti 1– x Hf x)O 3 (0 ≤ x ≤ 0.1) microwave dielectric ceramics were synthesized by solid-state reaction method. The effects of Hf substitution for the Ti-site on the phase composition, structure, and microwave dielectric properties of MgTiO 3 ceramic were systematically investigated. The study demonstrated that Hf substitution significantly improved the quality factor of MgTiO 3 ceramic. A single phase was confirmed at x = 0.002 and 0.005 by XRD and SEM, while secondary phases were observed at x ≥ 0.02. The Rietveld refinement of XRD data implied that the distortion of [Ti(Hf)O 6 ] octahedron started with alleviation and then gradually deteriorated with an increase in Hf content. Raman spectra displayed that the frequencies of the vibrational modes were high when there was low distortion in [Ti(Hf)O 6 ] octahedron, manifesting that the low distortion weakened the effect of non-harmonic vibration. The quality factor of the samples with x ≤ 0.05 was far higher than that of undoped MgTiO 3 , which may be related to low distortion in [Ti(Hf)O 6 ] octahedron and high relative density. Notably, the excellent microwave dielectric properties of Q × f ∼336,829 GHz, ε r ∼17.2 and τ f ∼ - 49.7 ppm/°C were achieved for the Mg(Ti 0.995 Hf 0.005)O 3 ceramic. The greatly improved quality factor of MgTiO 3 -based microwave ceramics through Hf substitution makes it a suitable candidate material for ceramic filters. [ABSTRACT FROM AUTHOR]

Currently, it is widely reported that the photovoltaic effect in ferroelectric materials can be promoted by the application of a piezoelectric force, an external electric field, and intense light illumination. Here, a semiconducting ferroelectric composition is introduced, (1−x) Ba0.06Bi0.47Na0.47TiO3‐xMgCoO3 (abbreviated as xMgCo, where x = 0.02–0.08), synthesized through Mg/Co ions codoping. This process effectively narrows the optical bandgaps to a spectrum of 1.38–3.06 eV. Notably, the system exhibits a substantial increase in short‐circuit photocurrent density (Jsc), by the synergy of the electric, light, and thermal fields. The Jsc can still be further enhanced by the extra introduction of a force field. Additionally, the Jsc also shows an obvious increase after the high field pre‐poling. The generation of a considerable number of oxygen vacancies due to the Co2+/Co3+ mixed valence state (in a 1:3 ratio) contributes to the reduced optimal bandgap. The integration of Mg2+ ion at the A‐site restrains the loss and sustains robust ferroelectricity (Pr = 24.1 µC cm−2), high polarizability under an electric field, and a significant piezoelectric coefficient (d33 = 102 pC N−1). This study provides a novel perspective on the physical phenomena arising from the synergy of multiple fields in ferroelectric photovoltaic materials. [ABSTRACT FROM AUTHOR]

• Graphene/PbSe composite was synthesized by a facile hydrothermal method. • Mid-infrared saturable absorption and modulation depth of Graphene/PbSe have been much enhanced compared with pure graphene. • Mid-infrared saturable absorption mirrors were fabricated by spin-coating Graphene/PbSe on gold-plated silicon substrates. • Stable Q-switched Er:YAP bulk laser was realized at ∼ 2.8 µm with the pulse width 326 ns, repetition rate 107 KHz and the average output power 498 mW. The suitably large modulation depth of the saturable absorber (SA) is crucial to obtaining short pulse lasers via passive Q-switching or mode-locking techniques. Graphene could theoretically be used as a mid-infrared (mid-IR) SA due to its zero band-gap. However, the low modulation depth of graphene in the mid-IR region limits its applications. In this work, to improve the mid-IR modulation depth of graphene, a strategy of functionalizing graphene with narrow-band gap semiconductors was adopted. Graphene/PbSe (G/PbSe) composite was synthesized by a facile hydrothermal process and the reflective G/PbSe SA was prepared by spin-coating method. The saturation absorption properties were investigated by the open aperture Z-scan technique. The results indicated that the saturation absorption properties of G/PbSe SA were largely enhanced, and the modulation depth was increased from 3.02 % to 5.4 % at ∼ 2.8 μm and from 2.5 % to 6.4 % at ∼ 4 μm compared with pure graphene. Moreover, with the as-prepared reflective G/PbSe SA, passively Q-switched Er:YAP laser operation at ∼ 2.8 µm was realized. At the pump power of 6.78 W, the pulse train with pulse width of 326 ns and repetition rate of 107 kHz was obtained, and the average output power was 498 mW. This study presents a way for preparing graphene-based mid-IR SAs for short pulse mid-IR lasers. [ABSTRACT FROM AUTHOR]

The inversion asymmetry of polar crystals enables ferroelectric ceramics to possess unique physical properties, among which the anomalous photovoltaic effect drives their potential application in photovoltaic conversion. Semiconducting (1−x) KNbO3−xBaNi.5Hf.5O3−δ (KNBNH, x = 2, 4, 6, 8%) ferroelectric ceramics with enhanced photovoltaic performance were prepared by utilizing conventional solid‐state sintering strategies. In these ceramics, the defect‐induced bandgap intermediate state is derived from the 3d split state of Ni and plays a dominant role in lowering the bandgap of KN. The defective bandgap state induced by Ni in KNBNH promotes its absorption of light and the separation of photogenerated carriers, thus enhancing its photovoltaic response. The KNBNH6 shows a maximum value of 138.7 nA/cm2 for short‐circuit photocurrent density (Jsc) among these ceramics, which is further enhanced to 702.9 nA/cm2 after 30 kV/cm polarization. Structural investigations after polarization indicate that polarization induced lattice distortion in KNBNH6, leading to an increase in the polarity of its cells. This work provides an understanding of defect‐induced bandgap states and high‐field polarization to enhance ferroelectric photovoltaic properties. [ABSTRACT FROM AUTHOR]

The AC impedance of SrTiO3, Ca0.9Sr0.1TiO3, Ca0.7Sm0.2TiO3, and Ca0.7Sm0.3Ti0.7Al0.3O3 microwave dielectric ceramics with perovskite structures has been analyzed. The impedance spectroscopy results reveal the electrical properties of this series of samples vary significantly with the ceramic microstructure and electrical homogeneity. The εr values of grains for SrTiO3 and Ca0.9Sr0.1TiO3 ceramics are 193.8 and 138.1, respectively, confirming that dielectric response of the high‐εr microwave ceramics is contributed to the grains, at microwave frequencies. Impedance spectroscopy of Ca0.7Sm0.2TiO3 ceramic illustrates that electrical heterogeneous microstructures include interior grains and grain shells. The secondary phase existing in Ca0.7Sm0.2TiO3 ceramic causes deviation in bulk permittivity, resulting in a higher εr ~ 148 of grains than εr ~ 112 of bulk permittivity, measured at microwave frequencies. Grain and grain‐boundary impedance of Ca0.7Sm0.3Ti0.7Al0.3O3 ceramic cannot be separated completely. The permittivities of grains and grain boundaries in Ca0.7Sm0.3Ti0.7Al0.3O3 ceramic are εg ~ 17.8 and εgb ~ 20.8, and the combination of them is close to εr ~ 40 at microwave frequencies. The LogI−LogU curves of the ceramic system indicate that the conducting mechanism of grains and grain boundaries follows ohmic behavior. [ABSTRACT FROM AUTHOR]

Background: The silicified cell wall of diatoms, also known as frustule, shows huge potential as an outstanding bio-nanomaterial for hemostatic applications due to its high hemostatic efficiency, good biocompatibility, and ready availability. As the architectural features of the frustule determine its hemostatic performance, it is of great interest to develop an effective method to modify the frustule morphology into desired patterns to further improve hemostatic efficiency. Results: In this study, the gene encoding Silicalemma Associated Protein 2 (a silicalemma-spanning protein) of Cyclotella cryptica (CcSAP2) was identified as a key gene in frustule morphogenesis. Thus, it was overexpressed and knocked down, respectively. The frustule of the overexpress lines showed no obvious alteration in morphology compared to the wild type (WT), while the size, specific surface area (BET), pore volume, and pore diameter of the knockdown strains changed greatly. Particularly, the knockdown frustules achieved a more pronounced coagulation effect and in vivo hemostatic performance than the WT strains. Such observations suggested that silicalemma proteins are ideal genetic encoding targets for manipulating frustule morphology associated hemostatic properties. Furthermore, the Mantel test was adopted to identify the key morphologies associated with C. cryptica bleeding control. Finally, based on our results and recent advances, the mechanism of frustule morphogenesis was discussed. Conclusion: This study explores a new strategy for enhancing the hemostatic efficiency of the frustule based on genetic morphology modification and may provide insights into a better understanding of the frustule morphogenesis mechanism. [ABSTRACT FROM AUTHOR]

Crystal structures and microwave dielectric properties of (1- x ) LaGaO 3 - x SrTiO 3 ( x = 0.4, 0.5, 0.6) and 0.4SrTiO 3 0.6LaGaO 3 - y CeO 2 ( y = 0, 0.05, 0.1, 0.2) ceramics were investigated. As the x values increased, the orthorhombic changed to tetragonal perovskite structure at x = 0.6 in LaGaO 3 -SrTiO 3 system ceramics. However, numerous secondary phases were detected in LaGaO 3 - SrTiO 3 system ceramics. Surprisingly, CeO 2 additives could effectively suppress formation of secondary phases of 0.4SrTiO 3 -0.6LaGaO 3 ceramics as Ce ions could be incorporated into host crystal lattices, leading to significantly improvement of optimal Q × f values from 35,354 GHz to 62,150 GHz. The Raman spectra exhibited that the modes associated with CeO 2 phase became more obvious with increasing CeO 2 additives. The 0.4SrTiO 3 0.6LaGaO 3 -0.05CeO 2 ceramics, sintered at 1475 °C/4 h, exhibited superior microwave dielectric properties with ε r = 32.9, Q × f = 62,150 GHz and τ f = − 26.6 ppm/°C. [ABSTRACT FROM AUTHOR]

GeSe exhibits in-plane optical anisotropy similar to black phosphorus and other two-dimensional materials, so it is believed to have remarkable nonlinear optical (NLO) properties. In this work, amorphous GeSe films were prepared by vacuum thermal evaporation. After annealing at 450 °C, GeSe films exhibited a polycrystalline phase. The NLO properties of these GeSe films were investigated by the Z-scan technique. The results indicated that GeSe films exhibited typical reverse saturable absorption (RSA) and self-focusing phenomenon. It was also found that the nonlinear optical parameters and laser-induced damage threshold of annealed recrystallized GeSe films were significantly improved. The nonlinear absorption and refractive coefficients were β = (2.90 ± 0.06)×10−7 m/W and n 2 = (1.06 ± 0.07)×10−13 m2/W at the incident laser intensity of 0.4 GW/cm2, respectively. The polycrystalline GeSe film showed remarkable RSA-induced optical limiting properties, which exhibited an optical limiting starting threshold of 0.018 GW/cm2 and an optical limiting threshold of 0.98 GW/cm2. These results strongly indicate that GeSe films have potential applications in solid-state optical limiting devices and laser protection. [ABSTRACT FROM AUTHOR]

Dielectric materials have attracted considerable attention owing to their excellent power densities and fast charge/discharge characteristics. AgNbO 3 , as a typical antiferroelectric (AFE) material, is regarded as a promising dielectric material owing to its large polarization value and environmentally friendly nature. However, the low energy density of this system limits its further application. In this study, the slim P-E loops are implemented by Gd/Ta substitution at A/B sites, which provide a superior energy storage performance with a W rec of 6.99 J/cm3 under 400 kV/cm. This improvement in energy storage property can be attributed to three factors: firstly, a significant improvement in the AFE stability is obtained by reducing the tolerance factor t and the B-site polarizability; secondly, this strategy leads to a reduction in the grain size of the material, optimizing the breakdown electric field E b of AN-based ceramics; lastly, A/B-site codoping induces structural distortion of the material, constructs an internal chemical pressure, and suppresses its oxide octahedral tilting. Furthermore, the Gd/Ta co-doped ceramics exhibit an excellent practical charging/discharging efficiency (＜10 μs). This work demonstrates that the electrical properties of AN-based ceramics have been optimized by Gd/Ta codoping, making them good candidates for pulsed power systems. [ABSTRACT FROM AUTHOR]

We studied the tunable three-photon absorption (3PA) response of colloidal CdSe nanocrystals in near-infrared by surface states which were successfully controlled with a purification process. The 3PA cross section at room temperature was decreased by more than two orders of magnitude when the density of surface traps increases and works through the photoinduced and intrinsic dipole moments of excitons, indicating that the surface-tuned three-photon absorption of CdSe was of significance in potential applications. [ABSTRACT FROM AUTHOR]

The CdSe nanocrystals (NCs) were synthesized by a hot injection method in the atmospheric environment without any protective gas. The size of CdSe NC was tuned by controlling the growth time and the NCs' high-quality was confirmed by UV–visible spectroscopy, photoluminescence spectroscopy, X-ray diffraction and transmission electron microscopy. A large third-order nonlinear optical (NLO) absorption of CdSe NCs was obtained by using Z-scan technique with 30 ps excitation at 532 nm, which was tunable with variable size and the energy difference between the first exciton absorption peak and the laser wavelength. The NLO susceptibility of CdSe NCs can reach as high as 1.81 × 10 −10 esu at the size of 3.3 nm and at resonance absorption peak. [ABSTRACT FROM AUTHOR]

Background: At present, the conventional methods for determining photosynthetic products of microalgae are usually based on a large number of cell mass to reach the measurement baseline, and the result can only reveal the average state at the population level, which is not feasible for large-scale and rapid screening of specific phenotypes from a large number of potential microalgae mutants. In recent years, single-cell Raman spectra (SCRS) has been proved to be able to rapidly and simultaneously quantify the biochemical components of microalgae. However, this method has not been reported to analyze the biochemical components of Cyclotella cryptica (C. cryptica). Thus, SCRS was first attempt to determine these four biochemical components in this diatom. Results: The method based on SCRS was established to simultaneously quantify the contents of polysaccharide, total lipids, protein and Chl-a in C. cryptica, with thirteen Raman bands were found to be the main marker bands for the diatom components. Moreover, Partial Least Square Regression (PLSR) models based on full spectrum can reliably predict these four cellular components, with Pearson correlation coefficient for these components reached 0.949, 0.904, 0.801 and 0.917, respectively. Finally, based on SCRS data of one isogenic sample, the pairwise correlation and dynamic transformation process of these components can be analyzed by Intra-ramanome Correlation Analysis (IRCA), and the results showed silicon starvation could promote the carbon in C. cryptica cells to flow from protein and pigment metabolism to polysaccharide and lipid metabolism. Conclusions: First, method for the simultaneous quantification of the polysaccharide, total lipid, protein and pigment in single C. cryptica cell are established. Second, the instant interconversion of intracellular components was constructed through IRCA, which is based on data set of one isogenic population and more precision and timeliness. Finally, total results indicated that silicon deficiency could promote the carbon in C. cryptica cells to flow from protein and pigment metabolism to polysaccharide and lipid metabolism. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) Ruddlesden–Popper perovskites have attracted extensive attention in photodetectors (PDs) due to their exceptional optoelectronic properties. The performances of PDs show extremely strong dependence on defects in 2D perovskites. Herein, high quality and less defective BA2FAPb2I7 perovskite films were obtained by a simple one-step spin coating method with rare earth doping assisted crystal growth. Furthermore, BA2FAPb2I7 perovskite films were used as photoresponsive materials to fabricate architectural simplicity photoconductor PDs. Under 405 nm laser illumination, the PDs show remarkable balance detect properties with a low dark current of 5.1 × 10−11 A, a large on/off ratio of 2.2 × 105, a high responsivity (R) of 4.51 A/W, an outstanding detectivity D shot * of 4.31 × 1013 Jones, and a response speed of 80 μs/76 μs. The R and D shot * of the PDs are outstanding in the reported quasi-2D perovskite PDs with the same structure. Our work not only paves an indubitably feasible way for fabrication of quasi-2D perovskite PDs via improving their natural material properties but also provides a clear direction for further enhancing the performance of other perovskites optoelectronics. [ABSTRACT FROM AUTHOR]

Third‐order nonlinear optical (NLO) absorption properties and ultra‐fast carrier dynamics of organic 4‐N,N‐dimethylamino‐4'‐N'‐methyl‐stilbazolium tosylate (DAST) at the wavelength of 520 nm are investigated by femtosecond open‐aperture Z‐scan technique and transient absorption spectroscopy, respectively. Z‐scan measurements indicate that DAST solution exhibits ultra‐high nonlinear saturable absorption (SA) responses with a figure of merit of 4.57 × 10−13 esu cm and a saturation strength of 3.20 GW cm−2, far superior to those of the most known 2D SA materials under similar excitations. Transient absorption results reveal that the outstanding SA performances of the solution‐phase DAST are rooted in ultra‐fast ground‐state bleaching based on the Pauli blocking effect. The subsequent excited state carrier relaxation processes are dominated by rapid intraband carrier cooling and defect‐assisted interband Auger recombination. Moreover, high‐quality DAST−polyvinyl alcohol composite films prepared by solution casting exhibit similar ultra‐high SA responses and reliable long‐term stability without any degradation of their SA responses even after exposure to air moisture for 100 days. These findings establish an experimental and theoretical foundation for the development of high‐performance ultra‐fast optoelectronic devices based on organic NLO materials in the future. [ABSTRACT FROM AUTHOR]

Background: Progress in the diagnosis and treatment of clear cell renal cell carcinoma (ccRCC) has significantly prolonged patient survival. However, ccRCC displays an extreme heterogenous characteristic and metastatic tendency, which limit the benefit of targeted or immune therapy. Thus, identifying novel biomarkers and therapeutic targets for ccRCC is of great importance. Method: Pan cancer datasets, including the expression profile, DNA methylation, copy number variation, and single nucleic variation, were introduced to decode the aberrance of copper death regulators (CDRs). Then, FDX1 was systematically analyzed in ccRCC to evaluate its impact on clinical characteristics, prognosis, biological function, immune infiltration, and therapy response. Finally, in vivo experiments were utilized to decipher FDX1 in ccRCC malignancy and its role in tumor immunity. Result: Copper death regulators were identified at the pancancer level, especially in ccRCC. FDX1 played a protective role in ccRCC, and its expression level was significantly decreased in tumor tissues, which might be regulated via CNV events. At the molecular mechanism level, FDX1 positively regulated fatty acid metabolism and oxidative phosphorylation. In addition, FDX1 overexpression restrained ccRCC cell line malignancy and enhanced tumor immunity by increasing the secretion levels of IL2 and TNFγ. Conclusions: Our research illustrated the role of FDX1 in ccRCC patients' clinical outcomes and its impact on tumor immunity, which could be treated as a promising target for ccRCC patients. [ABSTRACT FROM AUTHOR]

The manganese tricarbonyl complex {[Mn2(CO)6Mn(H2O)4(BPDC)2]·2H2O}n (1) (BPDC = 2,2′-bipyridyl-4,4′-dicarboxylic acid) was synthesized from the reaction of MnBr(CO)5 with 2,2′-bipyridyl-4,4′-dicarboxylic acid. Various fac-Mn(CO)3 cores based on mononuclear complexes were achieved and only a handful of the Mn(I)-based dinuclear metallastirrups or supramolecular rectangles were reported. Interestingly, our compound is the first example of a CORM with 1-D ladder-like chain and Mn(I)/Mn(II) mixed valence state. Studies show that 1 can release CO under three different wavelengths of light (Green: λ = 520–530 nm; Blue: λ = 465–470 nm; UV: λ = 365–370 nm) and CO releasing rate can be adjusted by changing the wavelength of the irradiation light. Density functional theory (DFT) calculations were conducted to analyze the effect of metal-to-ligand charge transfer (MLCT) on CO releasing behaviors. Furthermore, cellular viability assay and anti-inflammatory activities showed that 1 possessed biological compatibility but no systemic cytotoxicity, and could prevent LPS-induced secretion of TNF-α and NO in RAW264.7 cells. The results suggest that 1 may provide a therapeutic approach for inflammation. [ABSTRACT FROM AUTHOR]

A bandgap‐tunable KNbO3 ferroelectric ceramic was prepared by introducing Bi/Co ion. The existence of mixed valence states of Co2+/Co3+ in the system induced the bandgap reduction and its tunable behavior. KNbO3–BiCoO3 solid solutions showed a typical orthogonal perovskite structure and maintained good ferroelectricity (Ps = 15.13 µC/cm2) and high‐field polarization ability. The devices based on the.98KNbO3–.02BiCoO3 sample exhibited an improved short‐circuit photocurrent density (Jsc) of 19.2 nA/cm2 under simulated solar radiation, and this was further enhanced to 79.8 nA/cm2 after a 60‐kV/cm polarizing. The structural analysis of the samples after polarization reveals the effect of ferroelectric polarization on photovoltaic performance. This work provides new insights into the effects of ferroelectric polarization on photovoltaic performance. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are widely explored owing to their excellent nonlinear optical (NLO) properties. However, researchers have mainly focused on designing new structures of MOF crystals to adjust the NLO response while ignoring the influence of the number of metal–ligand coordination bonds on the NLO properties of MOFs. In this study, the influence of the coordination numbers of MOFs on their NLO properties is studied for the first time. Herein, MOFs with different coordination numbers, using trifluoroacetic acid as an auxiliary agent, are synthesized and their NLO properties are tested using the Z‐scan technique. The results reveal that the NLO absorption properties of MOFs with high coordination numbers can be effectively modulated from saturable absorption to reverse saturable absorption by increasing the excitation intensity. First‐principles calculations show that a change in the coordination numbers leads to a change in the charge transfer from metal to ligand, thereby resulting in different NLO responses. The MOFs with a high coordination number have potential applications in novel optical switches or logic gates. These results provide a reference for the precise adjustment of the NLO properties of MOFs. [ABSTRACT FROM AUTHOR]

Graphene has broad prospects for application in photonic devices. However, its zero-band gap limits its nonlinear optical (NLO) properties, and thus, its application. In this study, we synthesized reduced graphene oxide modified by Mn-doped semiconductor CdS nanoparticles (RGO/CdS:Mn) via a solvothermal method to study the development of NLO properties of graphene. The structures, morphologies and basic physical properties of RGO, CdS, RGO/CdS, and RGO/CdS:Mn were characterized. The third-order optical nonlinearities were tested by the Z-scan technique using a mode-locked Nd:YAG laser operating at 532 nm with a 30 ps pulse width. The results showed that the nonlinear susceptibility and saturation absorption of RGO/CdS:Mn were 15.3 and 26 times higher than those of RGO, respectively. The mechanism of the enhancement was analyzed based on the charge transfer between and within the components, and Mn doping produced trapping effect. The significantly improved optical nonlinearity of RGO/CdS:Mn lays a foundation for its applications in photonic devices. [ABSTRACT FROM AUTHOR]

In order to modulate the nonlinear optical (NLO) properties of multi walled carbon nanotubes (MWCNTs) and make them applicable to ultrafast nonlinear optical devices, we fabricated a core satellite ZnS-Au nanostructure on the surface of MWCNTs via the solvothermal method. The structure and morphology of the MWCNTs-Au-ZnS product were characterized by means of the XRD, SEM and XPS, which showed that the ZnS-Au nanoassemblies were combined along with the MWCNTs through C S covalent bond and partial ionic bond. The optical nonlinearities of the MWCNTs-Au-ZnS system were investigated using the Z-scan technique under the excitation of 532 nm ps laser pulses and kinetically analyzed using the pump-probe transient absorption spectroscopy. The results showed that the saturation absorption (SA) coefficient and the third-order nonlinear susceptibility of the MWCNTs-Au-ZnS system were adjustable with the variation of the core-satellite structure. The intensity of the saturation absorption was tuned downward below that of the pure MWCNTs, while the susceptibility of the system was tuned upward above that of the pure MWCNTs, which were attributed to the combined action of two-photon absorption of ZnS, charge transfer in the system, trap states provided by Au and charge delocalization varying with the size. These tunable nonlinearities will expand the applications of the MWCNTs-Au-ZnS system in photonic devices. • Core-satellite structure of ZnS-Au is fabricated on the surface of MWCNTs via a solvothermal method. • The core-satellite structure is connected with MWCNTs via covalent bond and partial ionic bond. • The nonlinear absorption and refraction of the MWCNTs-Au-ZnS are tuned by changing the core-satellite structures. [ABSTRACT FROM AUTHOR]

gene ( NANOC-D6D) encoding a desaturase that removes two hydrogen atoms from fatty acids at delta 6 position was isolated from a cDNA library of Nannochloropsis oculata (Droop) D. J. Hibberd (Eustigmatophyceae). The unicellular marine microalga N. oculata synthesizes rich long chain polyunsaturated fatty acids (LCPUFAs), including eicosapentaenoic acid (20:5n-3, EPA). The deduced protein contains 474 amino acids that fold into 4 trans-membrane domains. The neighbor-joining phylogenetic tree indicates that NANOC-D6D is phylogenetically close to the delta-6 fatty acid desaturase of marine microalgae such as Glossomastix chrysoplasta, Thalassiosira pseudonana, and Phaeodactylum tricornutum. The gene was expressed in Saccharomyces cerevisiae INVScl to verify the substrate specificity of NANOC-D6D. Our results suggest that the recombinant NANOC-D6D simultaneously desaturates linoleic acid (LA) and α-linolenic acid (ALA). [ABSTRACT FROM AUTHOR]

• Nanosecond pulse laser welding of steel to Al thin sheets was achieved. • Highest lap shear force of 158.8 N was obtained at the line spacing of 0.06 mm. • Three fracture modes produced at various line spacings were clarified. • The effect of heat accumulation on joining process was elucidated. Nanosecond pulsed laser welding of 316L stainless steel and 6063 aluminum alloy thin sheets was performed. The influence of scan line spacing on the joining process was clarified. Large explosive hole and hot cracking defects including radial cracks and arc-shaped cracks occurred in the joint caused by excessive heat accumulation when the line spacing was 0.02 mm. The joints without oxidation were obtained. The thermal-induced penetration increment (TIPI) decreased with the increase of line spacing and reached the maximum value of about 162.24% with the line spacing of 0.02 mm. Fe 2 Al 5 and FeAl phases probably were produced at all the line spacings. However, FeAl and α-Fe phases in the form of banding structures were possibly generated only with the line spacing of no less than 0.06 mm. The shear force test results indicated that the maximum shear load of 158.8 N was achieved at the line spacing of 0.06 mm due to the large bonding area and fewer defects. Three fracture paths, namely, button pullout failure (BPF), interfacial failure (IF) and mixed fracture (MF) mode of BPF and IF were produced. The heat affected zone was the origin of BPF mode. Local deformation, pores and Fe-Al brittle phases led to the fracture paths of IF and MF. [ABSTRACT FROM AUTHOR]

• Al and steel foils were successfully joined via nanosecond pulsed laser welding. • Highest tensile shear force of 135.4 N was obtained at the frequency of 225 kHz. • Three fracture modes obtained at different frequencies were elucidated. • Two effects of pulse frequency on elemental diffusion were clarified. Nanosecond pulse laser welding of 6063 aluminum alloy and 316L stainless steel sheets with a thickness of 0.2 mm was performed. The effect of pulse frequency on the joining characteristics was investigated. The results showed that porosities and cracking defects with larger dimension and numbers were produced in joints at the frequency of 125 kHz, while fewer defects were obtained in the joints with the pulse frequency larger than 175 kHz. As the pulse thermal effect played a major role at the frequency of 125 kHz, diffusion and enrichment of aluminum elements occurred in almost the entire aluminum side of the weld, generating various intermetallic compounds such as FeAl, Fe 2 Al 5 and FeAl 3. As the frequency increased, the banding structures in the weld became more congregate, which were mainly the mixed phases of FeAl and Fe 2 Al 5. The shear force test results indicated that the highest shear force of 135.4 N was obtained when the pulse frequency was 225 kHz. The nailing effect of the wave-shaped weld structures and the absence of porosities led to desirable mechanical properties. Besides, three fracture modes, named by interfacial fracture (IF), substrate tearing failure (STF) and nugget pullout (NP), could be classified. The large interfacial porosities and dispersive distribution of brittle phases led to the IF mode. The distribution of the Fe-Al brittle phases at the weld edge resulted in the STF mode. The existence of microcracks at the bottom of the weld contributed to the NP mode. [ABSTRACT FROM AUTHOR]

A depolarized electric field (Edp) of ferroelectrics to boost the carrier separation and migration rate is critical to promote the field of visible light photocatalytic hydrogen evolution (PHE). Here, the PHE performance of high-field poled semiconducting (1 − x)KNbO3–xBa(Ni1/2Nb1/2)O3−δ (abbreviated as (1 − x)KN-xBNN, x = 0, 0.02, 0.05, 0.10, and 0.20) ferroelectric ceramics were systematically studied under full spectrum (λ > 320 nm) and visible light (λ > 420 nm), respectively. Benefiting from their narrow bandgap and sub-bandgap, all the Ba, Ni-modified KN ceramic powders exhibited a PHE response under visible light irradiation. Notably, the visible light PHE rate of the high-field poled 0.95KN–0.05BNN ceramic powder can be promoted to 415.16 μmol g−1 h−1, which is 17.8-fold higher than that of the unpoled sample (23.26 μmol g−1 h−1). The boosting PHE rate in poled samples can be attributed to the high-field polarization of the material, which can significantly affect the lattice structure and cause an ordered ferroelectric-domain structure to form a depolarized electric field (Edp). EPR spectroscopy indicated that the poled 0.95KN–0.05BNN sample exhibited a superior catalytic activity of ˙OH evolution compared with its unpoled counterpart, suggesting the dependence of high photocatalytic performance on the unique field-induced polarization structure by an outer electric field. Moreover, a higher photo-excited transient photocurrent in the poled 0.95KN–0.05BNN specimen further proved the positive effect of Edp on the photovoltaic response. The formation of Edp in the semiconducting (1 − x)KN–xBNN ferroelectric favors the separation and transportation of photogenerated carriers. Thus, the synergistic effect of narrow bandgap and high-field polarization ability is the key to enhance the visible light photocatalysis of semiconducting ferroelectrics. Boosting the visible light photoelectrochemical catalytic activity of semiconducting (1 − x)KN–xBNN ferroelectrics through high-field polarization may provide a useful strategy to design new ferroelectric-based semiconductor materials. [ABSTRACT FROM AUTHOR]

In the process of exploring ferroelectric semiconductors, a new system of (1−x) KNbO3–xSrFeO3−δ (x = 0.00‐0.20) was successfully synthesized via solid‐state reaction. The crystal structures, ferroelectric, dielectric, optical, and electrical properties were systematically characterized. The orthorhombic phase with Amm2 space group is detected in all the ceramics. In addition, the orthorhombic and tetragonal phases coexist in 0.80KNbO3‐0.20SrFeO3‐δ ceramic. The decrease in oxygen octahedron distortion induces a weak ferroelectric polarization. The existence of long‐range ferroelectric polarization order in all the ceramics is verified and the bandgap of the ceramics can be tuned to ~2.18 eV. The improved short‐circuit photocurrent density (Jsc) and open‐circuit voltage (Voc) of the poled 0.95KNbO3‐0.05SrFeO3−δ ceramic at 30 kV/cm are ~6.90 nA/cm2 and 0.04 V, respectively. The activation energies for electrical conductivity of the grains and grain boundaries from 0.90KN–0.10SF ceramic are 0.67 and 0.77 eV, respectively, which indicate the doubly ionized oxygen vacancies. This work provides a new way to tune the optical bandgap/ferroelectric properties of KNbO3‐based ceramics for potential application in ferroelectric photovoltaic and energy fields. [ABSTRACT FROM AUTHOR]

• The fatigue life of SiMo1000 is more sensitive to graphite morphology than the testing atmospheres. • Decreased nodularity causes reduced fatigue life and reduced decarburization resistance. • The synergy of corrosion and fatigue affects the fatigue life of SiMo1000 only when nodularity is low. The influence of graphite morphology on the corrosion-fatigue mechanism in the cast compacted graphite iron SiMo1000 is investigated. Two batches of SiMo1000 with the same chemical composition but different nodularity are tested using low-cycle-fatigue tests in argon and a synthetic exhaust atmosphere at 800 °C. Decreased graphite nodularity is found to significantly reduce the corrosion resistance of SiMo1000, causing severe decarburization on the sample surface. Besides, the fatigue life is also dramatically reduced with decreased graphite nodularity. The synergy of decarburization and fatigue is found to reduce fatigue life in one of the batches. [ABSTRACT FROM AUTHOR]

• CTi 0.42 V 1.58 phase was observed and confirmed at the interface. • Dynamic behavior during laser joining CFRP/Ti was captured. • Finding importance of the bonding width of the resin and fiber-resin mixture. • Numerical simulation model accurately predicted the trend of joining strength. Laser lap joining of carbon fiber reinforced plastics (CFRP) to titanium (Ti) alloy using various scanning speed was performed and the influence of scanning speed on joining process was investigated. The high speed camera was adopted to visualize the joining process and defects. The tensile-shear force was tested and the fracture surface was observed by optical microscope. Besides, the numerical simulation of temperature field was conducted to reveal the joining mechanism. The results indicated that fewer defects on titanium alloy surface and less bubbles inside CFRP were obtained with the experimental condition of higher scanning speed. Both mechanical interlocking and chemical bonding occurred at the interface. The compound layer was generated and was confirmed as CTi 0.42 V 1.58 phase because of the carburization of titanium alloy. The thickness of compound layer increased with the decrease of scanning speed. Tensile-shear force first increased and then decreased as the travelling speed increased. When the travelling speed was 0.8 m/min, maximum tensile-shear force of 1024 N was obtained. The bonding width of the resin, and bonding ratio of the mixture of carbon fibers and resin also reached the maximum value at this experimental condition. This behavior was verified by results of temperature field simulation that the melting temperature range of CFRP first increased and then declined as the scanning speed increased. The fluctuation of the tensile-shear force of the CFRP/Ti joint was also explained by the developed simulation model. [ABSTRACT FROM AUTHOR]

• Transformed corrosion impact on the fatigue life is observed in SiMo51. • The fatigue lifetime of D5S is barely affected by the testing atmospheres. • Corrosion decreases HK30's fatigue life by around 50%. To increase the understanding of the corrosion-fatigue mechanisms in two cast iron-alloys used in exhaust manifolds, low-cycle fatigue tests at 800 °C in argon and synthetic diesel exhaust as well as isothermal oxidation tests in the exhaust atmosphere are conducted. The corrosion impacts on the fatigue life of the materials are quantitatively evaluated from comparing the ∊ -N curves, and examined from characterization through SEM, EDX, EBSD and EPMA. The materials show very different behaviors to the synergistic effect of corrosion and fatigue. Different theories have been suggested based on the findings. [ABSTRACT FROM AUTHOR]

Underwater local dry laser welding of TC4 alloy was carried out through a double-side gas-shielding nozzle, and the heat input and defocus distance were optimized by analysing the weld quality. With increasing heat input, the fusion zone (FZ) and heat-affected zone (HAZ) expanded, while the amount of vapour increased, resulting in an increase in the degree of oxidization of the underwater joint; the mechanical properties improved initially and subsequently deteriorated, influenced by bead oxidization and welding defects. With increasing defocus distance, the width of the FZ increased gradually, whilst the width of the HAZ remained largely unchanged. Excellent tensile strength and impact toughness were obtained when the laser beam was focused on the upper surface. In the FZ of the underwater laser welding (ULW) joint, the microstructure comprised full martensite α′ with an acicular morphology, whereas a small amount of grain boundary α-phase appeared in the FZ of the in-air joint, and the thickness of the α′ lamellae decreased compared to that of the in-air joint due to the higher cooling rate of the ULW joint. The impact toughness and tensile strength of the underwater joint reached ˜90% of the values for the in-air joint, and a mixed fracture mode was operative in the fracture surfaces. [ABSTRACT FROM AUTHOR]

• MoSe 2 /graphene composites were well prepared via a facile solvothermal method. • Novel MoSe 2 submicro-spheres had changed to be a network structure on the graphene. • An electron donor-acceptor model and energy level analysis were proposed. • The composite materials showed enhanced third-order optical nonlinearity. We prepared the MoSe 2 /graphene composite materials via a facile solvothermal method and investigated their third-order nonlinear optical properties. Structure and morphology characterizations of the MoSe 2 /graphene composite materials showed that MoSe 2 nanosheets formed a network structure on the surface of graphene nanosheets. The third-order nonlinear optical properties of synthesized materials were measured by using Z-scan technique with 30 ps pulse laser at 532 nm. The results showed that both MoSe 2 and MoSe 2 /graphene composite materials had saturable absorption and positive nonlinear refraction properties. An electron donor-acceptor model was considered to explain the enhanced charge transfer property, and synergistic effect between the graphene and MoSe 2 could be the major enhancement on the nonlinear optical property in comparison with graphene. Our results not only pave the way of two-dimensional materials for the photonic research, but also widen their potential applications in saturable absorbers and optical switches. [ABSTRACT FROM AUTHOR]