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Accurate estimation of the absorption of chromophoric dissolved organic matter (CDOM) in ultraviolet (UV) wavelength range is crucial for understanding photochemical and biochemical processes in the global ocean. Here, we propose a novel UV absorption extrapolation (UVAE) algorithm. It extrapolates the absorption coefficients (a g (λ) where λ is the wavelength in nm) of CDOM in the UV wavelength range from ocean color data in the visible wavelength range observed by satellite remote sensing. The extrapolation is based on the assumption that three characteristic Gaussian bands describe the CDOM UV–visible absorption spectra (275–443 nm). The UVAE algorithm retrieves the a g (275), a g (295), a g (330), and a g (380) using the characteristics of the spectral slope (S) of the absorbance spectra of CDOM at specific wavelength intervals, namely 275–295, 295–330, 330–380, and 380–443 nm. With the UVAE algorithm, the spatial variability of CDOM spectral features can be captured on a global scale using data from the Moderate-resolution Imaging Spectroradiometer (MODIS) Aqua mission. The retrieved a g (275), a g (295), a g (330), and a g (380) values match well with in-situ observed values, with mean absolute percent differences (MAPDs) of 19.2 %, 26.1 %, 36.9 %, and 46.6 %, respectively. The performance of the UVAE algorithm demonstrates a significant improvement compared to that of existing algorithms, especially for a g (λ) at lower wavelengths. [ABSTRACT FROM AUTHOR]

The stable oxygen isotope composition of precipitation (δ18Op) in southern China is considered as a valuable proxy of climatic conditions. However, their interpretations have been controversial. In this study, based on the observed and simulated data (isoGSM2) on oxygen isotope composition of precipitation, the linkage between summer precipitation (P) and δ18Op in the Dongting Lake basin and their possible influencing factors were investigated. The results indicate that the interannual variation of summer δ18Op is consistent with that of annual δ18Op. They both show a significantly negative correlation with the summer P, suggesting that the stable isotope composition in precipitation may be considered as a proxy of summer precipitation in the Dongting Lake basin. Statistically, the amount effect and circulation effect are significant in the isotope composition of precipitation in the basin. Based on either the observed data in Changsha or the simulated data for the basin, the local amount effect appears more important than large‐scale circulation for δ18Op during extreme summers. These results can potentially improve the reconstruction of paleoclimate in the East Asian monsoon region. Further study is needed to determine the contribution of local and large‐scale factors to the oxygen isotope composition of precipitation and to quantify the integral rainout along the moisture transporting paths. [ABSTRACT FROM AUTHOR]

Bi 2 WO 6 /AgIO 3 (BWO/AIO) nanosheet composites were constructed by a two-step hydrothermal method. The structure, morphology and photoelectrochemical properties of the composites were characterized by X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (UV-DRS), transmission electron microscopy (TEM), impedance, X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The constructed photocatalyst composites exhibited the best photocatalytic performance at a molar ratio of BWO/AIO-0.8. In addition, there was complete degradation of RhB by the BWO/AIO-0.8 in 180 min under illumination, and the bactericidal rates were 99.10%, 97.32% and 96.3% for P. aeruginosa , S. aureus and E. coli, respectively, in 60 min. Based on the energy band structure of the semiconductor and radical trapping experiments, the S-scheme heterojunction was associated with the enhanced photocatalytic properties. [ABSTRACT FROM AUTHOR]

A new semi-analytical algorithm that retrieves the total concentration of suspended matter (TSM) was derived from the China Eastern Coastal Zone using multiple ocean colour instruments including the Visible Infrared Imaging Radiometer (VIIRS), the Moderate-resolution Imaging Spectroradiometer (MODIS), and the Medium Resolution Spectral Imager II (MERSI II). The algorithm in one model derives TSM concentration (CTSM) from satellite inherent optical properties products for clear and moderately turbid water. For turbid waters, a second model with a four-band approach was used. The two model algorithms were combined into one algorithm using a linking weighted function to generate a smooth CTSM for clear and turbid water and for water with intermediate transparency. Compared to eight existing algorithms, our new algorithm performed better with a wide dynamic range for the CTSM retrievals. The mean absolute percent difference was 28.22% for the CECZ data and the CTSM varied from 0.5 mg l−1 to 2435.4 mg l−1. New algorithm decreased the MAPD by >11% for the CTSM retrievals compared to the eight existing algorithms. Furthermore, when new algorithm was tested with a synthetic data set that had been contaminated with residual error, it exhibited more residual error tolerance than the other algorithms when retrieving CTSM, which agreed well with the results provided by a multi-mission consistency analysis. These results indicate that new algorithm could provide accurate and consistent multi-mission CTSM from turbid coastal water with a widely varying range of CTSM. [ABSTRACT FROM AUTHOR]

The Ti-Ni-Hf shape memory alloy powders were prepared by plasma rotating electrode process. And the powders were featured with the perfect sphericity and smooth surface. Moreover, the grain size was refined in the Ti-Ni-Hf alloy powders due to the rapid cooling rate during plasma rotating electrode process. It was found that the Ti-Ni-Hf alloy powders had the typical self-accommodation configuration including spear-like, mosaic-like and lath-like martensite. Various twins, such as (001) compound twin, (011) type I twin as well as {111} type I twin, were observed in Ti-Ni-Hf alloy powders. Differing from the bulk Ti-Ni-Hf alloy, two-stage transformation corresponding to B2⇌B19' martensitic transformation was detected in the as-received Ti-Ni-Hf alloy powders. In addition, the martensitic transformation behaviors were closely related to the annealing temperatures. The Ti-Ni-Hf alloy powders with low annealing temperature of 500 ​°C still exhibited two-stage martensitic transformation, while two-stage martensitic transformation changed into single martensitic transformation in the Ti-Ni-Hf alloy powders with the higher annealing temperature of 900 ​°C. And finally the possible mechanisms for the evolution of martensitic transformation behaviors were discussed. [Display omitted] • High temperature Ti-Ni-Hf alloy powders were prepared successfully by PREP. • Ti-Ni-Hf alloy powder possessed the perfect sphericity and pure surface. • The transformation behaviors were closely related to the annealing temperatures. • The mechanisms of multi-stage martensitic transformation were explained. [ABSTRACT FROM AUTHOR]

We present an alternative approach proposed by Albrecht to derive general order conditions for Runge-Kutta-Nyström methods and relate it to the classical RKN-theory. The RKN-methods are treated as composite linear methods to yield the general order conditions as orthogonal relations. We then exploit the orthogonal structure of the order conditions and obtain a simple recursion to generate the order conditions. Implications of this approach on the classical RKN-theory are discussed and it may be worthwhile to generalize the approach to other discretizations. [ABSTRACT FROM AUTHOR]

The microstructure of Nb 30 Ti 35 Co 30 Fe 5 eutectic alloy was investigated by using scanning electron microscope (SEM) and transmission electron microscope (TEM). The alloy exhibits typically lamellar eutectic structures which are composed of uniformly arranged nano-scale bcc-(Nb) phases and B2–Ti(Co, Fe) phases. 5 at% Fe partially substituting Co induced the composition modification of bcc-(Nb) phase such as the increasing Ti/Nb ratio and existing Fe solutes, which contributes to the enhanced hydrogen permeability. Nb 30 Ti 35 Co 30 Fe 5 eutectic alloy shows strong sustainability during hydrogen permeation under continuous hydrogen pressure and thermal cycles, and the hydrogen permeation flux can restore when the hydrogen pressure or temperature recovered again. No hydrogen induced fractures were found during hydrogen permeation. The present work demonstrates that Nb 30 Ti 35 Co 30 Fe 5 eutectic alloy exhibits excellent sustainability under the conditions of changing temperature and feed hydrogen pressure, which is very promising to be an alternative for Pd used for hydrogen separation and purification. • Nb 30 Ti 35 Co 30 Fe 5 consisted of uniformly arranged nano-scale dual phases. • Fe substitution leads to the optimized composition of bcc-(Nb) phase in eutectic. • Nb 30 Ti 35 Co 30 Fe 5 shows excellent sustainability under pressure and thermal cycles. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we propose an approach of combination of asymptotic and numerical techniques to solve highly oscillatory second-order initial value problems. An asymptotic expansion of the solution is derived in inverse of powers of the oscillatory parameter, which develops on two time scales, a slow time t and a fast time τ = ω t. The truncation with the first few terms of the expansion results in a very effective method of discretizing the highly oscillatory differential equation and becomes more accurate when the oscillatory parameter increases. Numerical examples show that our proposed asymptotic-numerical solver is efficient and accurate for highly oscillatory problems. [ABSTRACT FROM AUTHOR]

Abstract A duplex treatment of plasma nitriding (PN), followed by the deposition of a CrN/CrTiAlSiN/WCrTiAlN multilayer coating, was performed on AISI 4140 steel. Untreated, plasma-nitrided, only-coated (just the coating) and duplex-treated (PN + coating) AISI 4140 steel were microstructurally and mechanically characterized. The nitrided compound layer, consisting of mainly ε-Fe 2-3 N and γ′-Fe 4 N phases, was approximately 8.0 μm thick. The total thickness of the multilayer coating, which consisted of a top W-Cr-Ti-Al-N multilayer, a periodic Cr-Ti-Al-Si-N interlayer, and a CrN bottom layer, was 2.3 μm. The CrN/CrTiAlSiN/WCrTiAlN multilayered coatings possessed a super-hardness of 47.9 GPa and the highest elastic modulus of 424.8 GPa in the all samples. The microhardness (2200 HV 0.05) of the duplex-treated sample was significantly higher than that of the only-coated (740 HV 0.05) and nitrided (900 HV 0.05) samples. The scratch tests revealed that the adhesion strength of the duplex-treated sample increased significantly due to a gradient-hardness support of the coating-nitrided layer interface. Highlights • CrN/CrTiAlSiN/WCrTiAlN multilayer coating was successfully prepared. • It is consisted of a mixture of W 2 N, CrN, TiN and AlN phases. • Ultrahigh hardness is 47.9 GPa and high H3/E⁎2 ratio is 0.609. • W 2 N phases can further improve the structural integrity and mechanical properties. • Plasma nitriding improves the adhesion strength of the coating/substrates. [ABSTRACT FROM AUTHOR]

In this paper, a general family of derivative-free n + 1 -point iterative methods with n + 1 parameters is constructed by inverse interpolation for solving nonlinear equations. A general family of n -point iterative methods with the first derivative and n parameters is also constructed by inverse interpolation. They satisfy the conjecture of Kung and Traub (1974) that an iterative method based on n + 1 evaluations per iteration without memory would have optimal order 2 n. Furthermore, the two families are accelerated by divided difference expressions for the parameters with one memory f (x k − 1 , n) per iteration to achieve higher orders of convergence 2 n + 2 n − 1 and 2 n + 2 n − 2 , respectively. Finally, the proposed families are verified by solving nonlinear equations and applied to solve nonlinear ODEs. [ABSTRACT FROM AUTHOR]

We propose a modified Filon-type method for solving second-order highly oscillatory systems with a time dependent matrix. We first transform the second-order problem into a first-order one and then integrate the transformed one by the Filon-type method combined with the waveform relaxation method. The fundamental matrix in the formula of variation of constants can be calculated directly such that our proposed modified Filon-type method do not need to compute the nested integral commutators in the Magnus expansion. The global error of the modified Filon-type method is presented. Numerical examples show that our proposed numerical solver is efficient and accurate for highly oscillatory problems. [ABSTRACT FROM AUTHOR]

In this paper, we study efficient numerical integrators for linear and nonlinear systems of highly oscillatory second-order ordinary differential equations. The systems are reformulated as a first-order system, which is then transformed to adiabatic variables. The solution of the transformed system is a smoother function which is more accessible to numerical approximation than the original system. We develop Filon-type methods for linear systems by approximating the integral as a linear combination of function values and derivatives. We then present a special combination of Filon-type methods and waveform relaxation methods for nonlinear systems. Both types of methods can be used with far larger step sizes than those required by traditional schemes and their performance drastically improves as frequency grows, as are illustrated by numerical experiments. [ABSTRACT FROM AUTHOR]

In this paper, we provide a criterion on the axial equilibrium to be globally asymptotically stable for the n -dimensional Gompertz system, i.e., only one species will survive and stabilize at its own carrying capacity, whilst all the other species are driven to extinction. [ABSTRACT FROM AUTHOR]

We reported the highly toxic H 2 S sensor based on self-assembly gridding α-MoO 3 nanobelts prepared by electron beam vapor deposition method. With three dimensional surface modification of porous structures that self-assembly gridding α-MoO 3 nanobelts constructed, this sensor could detect H 2 S gas with the concentration of as low as 1 ppm and also possess the excellent selectivity and stability. More importantly, the ab initio molecular dynamics simulations was employed to elucidate the H 2 S gas adsorption mechanisms of sensor based on MoO 3 nanobelts by calculating three-dimensional dynamically changing images of electronic local functions of H 2 S-MoO 3 interface, firstly and directly predicting the interfacing action between H 2 S and MoO 3 . It unambiguously suggests the capability of self-assembly gridding α-MoO 3 nanobelts acting as a high toxic H 2 S gas sensor for environmental monitoring and safety forecast of poisonous gas in agricultural, industrial and medical fields, and the scientific significance in sight into the gas mechanisms of gas sensors alike. [ABSTRACT FROM AUTHOR]

Based on the mean-value theorem of multivariable vectors function F ( x ), two new iterative schemes with third-order and fifth-order convergence are constructed respectively by using Gauss quadrature formula for solving systems of nonlinear equations. Their error equations and asymptotic numerical convergence constants are obtained. The two suggested methods are compared with the related methods for solving systems of nonlinear equations and boundary-value problems of nonlinear ODEs in the numerical examples to demonstrate the efficiency and practicality. [ABSTRACT FROM AUTHOR]

• We assembled a 204-Mb high quality genome of rabbit tapeworm (Taenia pisiformis) containing 45.94% repeat content. • We identified a total of 12,097 high-confidence protein-coding genes with > 96% of them supported by transcript evidence. • Genome-level phylogenetic analysis revealed that T. pisiformis diverged from its closely related relative T. hydatigena ∼ 14.6 Mya. • Comparative analysis with other helminth genomes suggests that T. pisiformis have undergone substantial adaptive evolutions. Taenia pisiformis is one of the most widespread gastrointestinal parasites and its larvae (cysticercosis) causes significant economic loss to rabbit industry. No efficient drug is available for this disease to date. To better understand its genomics, we assembled a 211-Mb high quality genome of T. pisiformis at chromosome level with a scaffold N50 size of 20 Mbp. Totally, 12,097 protein-coding genes was predicted from the genome. Genome-level phylogenetic analysis confirmed the taxonomic affiliations with other tapeworms and revealed that T. pisiformis diverged from its closely related relative T. hydatigena ∼ 14.6 Mya. Comparative genomic analyses revealed that the T. pisiformis genome was characterized by adaptive features of strong positive selection signals from carbohydrate/lipid metabolism and body surface integrity, and of expanded gene families related to metabolism of amino acids and lipids. The high-quality genome of T. pisiformis constitutes a resource for the comparative genomics and for further applications in general parasitology. [ABSTRACT FROM AUTHOR]

Numerical simulations of bending, performing, and hydroforming processes of automotive swing arms for torsion beam were conducted using finite element analysis. The process parameters such as bending radius, mandrels, loading paths, and calibration pressure were optimized in the simulation. In addition, closing force was predicted by die stress-strain analysis using the elastic finite element method. Subsequently, the bending, performing, and hydroforming experiments were performed based on the simulation results. The experimental results indicated that swing arms could be fabricated when the bending radius, calibration pressure, and closing force would be of 120 mm, 150 MPa, and 15,000 kN, respectively. Finally, swing arms with high thickness uniformity were obtained and the thickness distribution between numerical and experimental results was well consistent. [ABSTRACT FROM AUTHOR]

Numerical simulations of the hydroforming process of Ti/Al clad T-shapes were conducted by using finite element analysis software. These simulations were used to optimize process parameters such as internal pressure, feed distance, and friction coefficient. Subsequently, hydroforming experiments were conducted based on these simulations. The results indicated that Ti/Al clad tubes could be obtained in the practical hydroforming process under the following forming conditions: internal pressure of 110 MPa, feed distance of punches of 25 mm, and a friction coefficient of 0.1. This resulted in well-bonded micro-interface between titanium and aluminum that is free from any delamination. The protrusion height of Ti/Al clad T-shapes were 25.5 mm and had high thickness uniformity. [ABSTRACT FROM AUTHOR]

• An octahedral flower-like ZnIn 2 S 4 /Bi 2 WO 6 photocatalyst was synthesized. • The octahedral flower-like ZnIn 2 S 4 /Bi 2 WO 6 is constructing S-scheme mechanism. • It displays significantly visible-light-driven photocatalytic performance. In this study, we fabricated octahedral flower-like ZnIn 2 S 4 /Bi 2 WO 6 (ZIS/BWO) composite photocatalysts employing octahedral Bi 2 WO 6 nanocones and sheet ZnIn 2 S 4 by in-situ growth method. The synthesized composites were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and X-ray powder diffraction (XRD), respectively. It can be observed that ZnIn 2 S 4 nanosheets grows from the surface of the Bi 2 WO 6 nanocone to form octahedral flower-like ZIS/BWO nanocone composite photocatalysts. The prepared ZIS/BWO composite photocatalysts are speculated that it conforms to the S-scheme heterojunction by UV–vis diffuse reflectance spectra (UV-DRS) and electrochemical analyses combing with the redox potential of reactive oxygen species. The S-scheme heterojunction of ZIS/BWO composite photocatalysts exhibits good separation and transportation of photogenerated carriers by photocurrent and photoluminescence (PL). In addition, the ZIS/BWO composites with S-scheme heterojunction enhances photocatalytic degradation Rhodamine B (RhB), which still showed good photocatalytic activity (62.4%) after four consecutive cycles of photodegradation experiments. This S-scheme heterojunction of the unique structure will be potential and promising photocatalytic catalysts for environmental purification and energy conversion in the coming years. [ABSTRACT FROM AUTHOR]

For some casting low-alloy steels, traditional quenching and tempering heat treatments can improve the strength; however, sometimes the ductility is not satisfied. Therefore, some kind of effective heat treatment method seems necessary; one which could improve the ductility, but not seriously affect the strength. In this paper, the effect of inter-critical quenching (IQ) on the mechanical properties of casting low-alloy steel was studied. IQ was added between quenching and tempering heat treatment; and the microstructure and mechanical properties were compared to the same steel with the traditional quenching and tempering treatments. The experimental results show that the microstructure comprises small-size ferrite and martensite when the IQ is adopted; and that different temperatures can control the ferrite quantity and distribution, and, as a result, influence the mechanical properties. In the case of IQ, the tensile strength decreases just a little, but the ductility increases a lot; and the strength-ductility product (its value is the arithmetic product of elongation and tensile strength) increases by between 6% and 10%, which means the IQ heat treatment can improve comprehensive mechanical properties. [ABSTRACT FROM AUTHOR]

The effect of different tempering temperatures on the microstructure and mechanical properties of airquenched high boron white cast iron was studied. The results indicate that the high boron white cast iron comprises dendritic matrix and inter-dendritic M2B boride; and the matrix comprises martensite and pearlite. After quenching in the air, the matrix is changed into lath martensite; but only 1-μm-size second phase exists in the matrix. After tempering, another second phase of several tens of nanometers is found in the matrix, and the size and quantity increase with an increase in tempering temperature. The two kinds of second precipitation phase with different sizes in the matrix have the same chemical formula, but their forming stages are different. The precipitation phase with larger size forms during the austenitizing process, while the precipitation phase with smaller size forms during the tempering process. When tempered at different temperatures after quenching, the hardness decreases with an increase in the tempering temperature, but it increases a little at 450 ° C due to the precipitation strengthening effect of the second phase, and it decreases greatly due to the martensite decomposition above 450 ° C. The impact toughness increases a little when tempered below 300 ° C, but it then decreases continuously owing to the increase in size and quantity of the secondary precipitate above 300 ° C. Considered comprehensively, the optimum tempering temperature is suggested at 300 ° C to obtain a good combination of hardness and toughness. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a variant of Steffensen’s method of fourth-order convergence for solving nonlinear equations is suggested. Its error equation and asymptotic convergence constant are proven theoretically and demonstrated numerically. The derivative-free method only uses three evaluations of the function per iteration to achieve fourth-order convergence. Its applications on systems of nonlinear equations and boundary-value problems of nonlinear ODEs are showed as well in the numerical examples. [Copyright &y& Elsevier]

Abstract: In this paper, high boron white cast iron, a new kind of wear-resistant white cast iron was developed, and its microstructure and mechanical properties were studied. The results indicate that the high boron white cast iron comprises a dendritic matrix and an interdendritic eutectic boride in as-cast condition. The distribution of eutectic boride with a chemical formula of M2B (M represents Cr, Fe or Mn) and with a microhardness of HV2010 is much like that of carbide in high chromium white cast iron. The matrix includes martensite and a small amount of pearlite. After quenching in air, the matrix changes to martensite, but the morphology of boride remains almost unchanged. In the course of austenitizing, a secondary precipitation with the size of about 1μm appears, but when tempered at different temperature, another secondary precipitation with the size of several tens of nanometers is found. Both secondary precipitations, which all forms by means of equilibrium segregation of boron, have a chemical formula of M23(C,B)6. Compared with high chromium white cast iron, the hardness of high boron white cast iron is almost similar, but the toughness is increased a lot, which attributes to the change of matrix from high carbon martensite in the high chromium white cast iron to low carbon martensite in the high boron white cast iron. Moreover, the high boron white cast iron has a good hardenability. [Copyright &y& Elsevier]

The evaluation of the hot workability of 5Cr5MoSiV1 steel with high deformation resistance is crucial for the controllability of the hot forging process. Based on the isothermal compression at deformation temperature of 950–1200 °C and strain rate of 0.01–10 s−1, the flow behavior of 5Cr5MoSiV1 steel is demonstrated. As the strain rate increases, the typical characteristics of the true stress–strain curve indicate that the dynamic softening mechanism changes from dynamic recrystallization to dynamic recovery. Moreover, the hot working window determined by the hot processing map from the modified J–C constitutive model is constructed for the forging process of the material. Through microstructure verification, the optimal hot working window is within the range of deformation temperature from 1000 to 1185 °C and strain rate from 0.01 to 0.202 s−1. Furthermore, the forging upsetting tests of the large cylindrical specimens are used to confirm the insecurity of hot deformation parameters outside the optimum hot working window. The implementation of this study can provide a theoretical basis for the determination of hot forging process parameters for 5Cr5MoSiV1 steel. [ABSTRACT FROM AUTHOR]

There are few existing experimental studies on the controversial diffusion behavior of hydrogen atoms across an individual grain boundary (GB). In this study, by combining Electron Back Scattered Diffraction (EBSD) and scanning Kelvin probe force microscopy (SKPFM) techniques, the transverse diffusion behavior of hydrogen atoms across a random GB with a misorientation of 45° within the directionally solidified high purity nickel was directly observed. The results suggest that the hydrogen atoms diffused perpendicular to the studied GB will be trapped by this GB, resulting in hydrogen segregation at the GB. In addition, the studied GB acts as a two-dimensional barrier that can block the transverse diffusion of hydrogen atoms. This present study reveals the real role played by a specific random GB on the hydrogen transverse diffusion and enriches the existing experimental research for intergranular diffusion. [Display omitted] [ABSTRACT FROM AUTHOR]

Taenia hydatigena is a widespread gastrointestinal helminth that causes significant health problems in livestock industry. This parasite can survive in a remarkably wide range of intermediate hosts and affects the transmission dynamics of zoonotic parasites. T. hydatigena is therefore of particular interest to researchers interested in studying zoonotic diseases and the evolutionary strategies of parasites. Herein we report a high-quality draft genome for this tapeworm, characterized by some hallmarks (e.g., expanded genome size, wide integrations of viral-like sequences and extensive alternative splicing during development), and specialized adaptations related to its parasitic fitness (e.g., adaptive evolutions for teguments and lipid metabolism). Importantly, in contrast with the evolutionarily close trematodes, which achieve gene diversification associated with immunosuppression by gene family expansions, in T. hydatigena and other cestodes, this is accomplished by alternative splicing and gene loss. This indicates that these two classes have evolved different mechanisms for survival. In addition, molecular targets for diagnosis and intervention were identified to facilitate the development of control interventions. Overall, this work uncovers new strategies by which helminths evolved to interact with their hosts. Wang and colleagues report a high quality draft genome for the thin-necked bladder worm, an agricultural livestock parasitic pest. Using this draft genome and comparison with other related parasites, they reveal gene families that are selectively pressured in different species, indicative of specialised survival strategies for different hosts. [ABSTRACT FROM AUTHOR]

Frequent and extensive sun glint is a serious obstacle to real-time monitoring of ocean colour anomalies. We semi-analytically adjust an inherent optical properties (IOPs) data processing system for the open ocean to correct for sun glint (called 'IDAS-SGC') and for remote sensing reflectance (Rrs) and IOPs retrievals. Tests with synthetic data validated the effectiveness of our algorithm in deriving ocean colour data from severely glint-contaminated images to produce high quality images. Evaluating results from single mission images suggested that our approach provides spatially smooth and consistent ocean colour products from both severe glint and glint-free regions for Visible Infrared Imaging Radiometer Suite and for Medium Resolution Spectral Imager II instruments. Specifically, complete coverage of circulation-caused ocean colour anomalies can be recovered from a single severe sun glint image. Comparing multi-mission images found that the inter-mission consistency for IDAS-SGC Rrs in sun glint regions is comparable with the inter-mission consistency in glint-free regions. Furthermore, we evaluate the performance of the Cox-Munk algorithm for sun glint estimation, and we find that our IDAS-SGC algorithm is more effective than the Cox-Munk algorithm in deriving Rrs products from severe sun glint regions due to the absence of accurate real-time wind data. Our results suggest that the IDAS-SGC algorithm obtains meaningful ocean colour products from sun glint-contaminated images of the open oceans. [ABSTRACT FROM AUTHOR]

• Gaussian bands in DAS reveal protonation-active functionalities in NOM. • DAS and FT-ICR-MS identify protonation-active molecules in NOM. • Genetic molecular network analysis identifies active chromophores in NOM molecules. • Molecular orbital theory interprets electronic transitions of active chromophores. Natural organic matter (NOM) is critical for the biogeochemical cycles of energy and many elements in terrestrial and aquatic ecosystems, and protonation-active functional groups in NOM molecules, notably carboxylic and phenolic groups often mediate these critical environmental functions. Molecular heterogeneity, polydispersity and dynamic behavior of NOM complicate achieving an unambiguous description of its molecular properties and reactivity. This study demonstrates that differential ultraviolet-visible (UV/VIS) absorbance spectra (DAS) of NOM acquired at varying pH values exhibit several distinct features associated with the deprotonation of NOM molecules, independent of the environmental provenance of NOM (e.g., surface water, seawater, sediment, and wastewater). The protonation-active functionalities that contribute to the Gaussian distribution bands present in the DAS were identified here by comparing characteristic properties of the bands with the stoichiometries of NOM molecules ascertained by Ultrahigh-Resolution Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS). The protonation-active individual chromophores universally present in NOM molecules were identified by a genetic molecular network analysis. The observed DAS features were closely modeled via superimposing DAS spectra of 51 individual protonation-active chromophores. Molecular orbital theory was applied to further interpret the deprotonation of these chromophores, their molecular structure, electron distribution, and electron transitions measured using DAS. The high sensitivity and easy implementation of the DAS approach allows using it as a powerful tool to quantify the molecular properties and reactivity of NOM at environmental concentrations. [Display omitted] [ABSTRACT FROM AUTHOR]

Wide bandgap β-Ga2O3 is an ideal candidate material with broad application prospects for power electronic components in the future. Aiming at the application requirements of β-Ga2O3 in space photoelectric devices, this work studies the influence of 40 MeV Si ion irradiation on the microstructure and optical properties of β-Ga2O3 epi-wafers. Raman spectroscopy analysis confirms that Si ion irradiation destroys the symmetric stretching mode of tetrahedral–octahedral chains in β-Ga2O3 epi-wafers, and the obtained experimental evidence of irradiation leads to the enhanced defect density of VO and VGa–VO from x-ray photoelectron spectroscopy. Combined with first-principles calculations, we conclude that most configurations of VO and VGa–VO are likely non-radiative, leading to quenching of experimental photoluminescence intensity. Unraveling optical degradation mechanism and predicting the optical application of β-Ga2O3 devices in the space environment by combining ground irradiation experiments with first-principles calculations still be one of the focuses of research in the future. [ABSTRACT FROM AUTHOR]

We report a high-performance phosphors-free white light-emitting-diodes (w-LEDs) using Ba2V2O7 or Sr2V2O7 quantum dots that directly heteroepitaxially grown on common quartz substrates by polymer assisted deposition (PAD). The quantum efficiency of quantum dots is as high as 95%. More importantly, electronic local functions, band structure and partial density of states have been firstly calculated to study the luminescent and heteroepitaxial growth mechanisms by the Ab-initio Simulation. Additionally, the glaring white light excited at a wavelength of 325 nm was experimentally observed, which unambiguously demonstrated that such quantum dots can be efficient w-LEDs for solid state lighting. [ABSTRACT FROM AUTHOR]

There was always a controversy about if the mobile dislocations generated during plastic deformation could transport hydrogen atoms. In this study, the behavior of dislocation migration hydrogen was directly observed by combining the scanning Kelvin probe force microscopy (SKPFM) technique and slow tensile test. The quantitative analysis results revealed that the behavior of dislocation transport hydrogen could not accelerate hydrogen atom migration, while could achieve the uphill transport of hydrogen atoms. In addition, in this study, SKPFM has been confirmed to be a powerful tool for measuring hydrogen diffusion coefficient in materials with a high accuracy. • SKPFM was a powerful tool for measuring hydrogen diffusion coefficient in materials. • The behavior of dislocation transport hydrogen was universal in general tensile tests. • Hydrogen transport could not be accelerated by the behavior of dislocation carrying. • The behavior of dislocation carrying hydrogen could achieve the uphill transport of hydrogen atoms. [ABSTRACT FROM AUTHOR]

China low activation martensitic steel/aluminum clad tubes were prepared by explosive bonding method in order to study its microstructure characteristics at the interface and to evaluate its performance. The interface morphology of the different parts of the clad tube was characterized by scanning electron microscope and energy dispersive spectroscopy. Then, the performance of the clad tube, including its bonding strength and formability, was investigated. Microstructural results showed that existence of an under-fusion area at the head of the clad tube, diffusion of elements, and the metallurgical bonding was observed in the middle part while cracks and crushing particles appeared at the end of the clad tube. No separation after the cold extruding and hydroforming process showed that the middle part of the clad tube had excellent bonding properties and could endure the second plastic deformation. [ABSTRACT FROM AUTHOR]

The substitutions of Ni and Ti/Ni by 5 at% Pd in Nb 51 W 5 Ti 23 Ni 21 alloy were performed and the alloying effects of Pd on microstructures and hydrogen transport properties were investigated. The description of hydrogen permeation flux based on hydrogen chemical potentials was applied to depict the dependence of hydrogen permeation flux on hydrogen solubility. Substituting Ni and Ti/Ni by Pd cause the reduced hydrogen solubility, leading to the enhanced resistance to hydrogen embrittlement. The Pd substituting Ni and Ti/Ni induce the decreased hydrogen permeation flux, which can be attributed to the decreased hydrogen solubility and the slightly decreased intrinsic hydrogen diffusion coefficient. The Nb 51 W 5 Ti 23 Ni 16 Pd 5 alloy membranes exhibits strong resistance to hydrogen embrittlement which shows no failure when cooled down to room temperature under hydrogen atmosphere. [Display omitted] • 5 at.% Pd substituting Ni and Ni/Ti were performed on Nb 51 W 5 Ti 23 Ni 21 alloy. • The hydrogen solubility decreased by 7.3% after 5 at.% Pd substituting Ni. • Nb 51 W 5 Ti 23 Ni 16 Pd 5 shows no hydrogen embrittlement failure when cooled down to room temperature. [ABSTRACT FROM AUTHOR]

Effluent organic matter (EfOM) discharged from wastewater treatment plants (WWTPs) carry substantial risks to river ecosystems. The fate and role of EfOM in the receiving water is affected by its exposure to sunlight and microbial processes, but the extent of these processes remains unclear. In this study, three-phase sequence of irradiation and microbial incubation with EfOM were conducted to compare the behavior of EfOM with that of natural organic matter in receiving rivers (RNOM). The dissolved organic carbon (DOC) in EfOM was degraded by 23% after three sequential phases, while that in RNOM was degraded by 19%. In the first phase, the irradiation of EfOM stimulated microbial respiration and growth by producing easily metabolizable less aromatic lignin-type molecules, leading to a 21% increase in biodegradation. Conversely, the irradiation of RNOM removed biodegradable lignin-type molecules, causing a 50% decreased in biodegradation. The second and third irradiation phases of EfOM and RNOM produced biodegradable lignin-type molecules, making their molecular compositions increasingly similar. The acute toxicity of EfOM decreased by 55%, and differences in microbial species composition between EfOM and RNOM waters decreased by 82% after the three-phase sequence. These findings can improve understanding of the fate of EfOM discharged into receiving rivers. [Display omitted] • The coupling of irradiation and microbial incubation increase 23% DOC degradation. • Irradiation of EfOM produced biodegradable less aromatic lignin-type molecules. • Molecular composition of EfOM became similar to that of NOM in receiving river. • Difference in microbial species in water containing EfOM and RNOM reduced by 82%. • Toxicity of EfOM reduced by 55% after photochemical and biological process. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we discuss two variants of Newton''s method without using any second derivative for solving nonlinear equations. By using the majorant function and confirming the majorant sequences, we obtain the cubic semilocal convergence and the error estimation in the Kantorovich-type theorems. The numerical examples are presented to support the usefulness and significance. [Copyright &y& Elsevier]

Rare earth doped down‐conversion (DC) materials, due to their unique spectral conversion characteristics, are promising candidates for narrow band solar‐blind ultraviolet (UV) light detection devices. Herein, an enhanced capture device for broadband solar‐blind UV light is constructed by combining an ordinary semiconductor with a DC spectrum converter, the essence of which is to introduce the appropriate alkali‐metal ions (Li+, Na+, and K+) into DC layer. Europium‐doped organic–inorganic composite films are used as spectral converters because of their excellent DC characteristic, which can convert broadband solar‐blind UV incident illumination into visible light suitable for capture by light dependent resistor (LDR). Interestingly, the spectral conversion efficiency is positively correlated with the capture ability of broadband solar‐blind UV photons. The introduction of alkali‐metal ions in the DC layer enhances the photon detection efficiency with an increase rate of around 200%, which is attributed to alkali‐metal ions changing the local crystal field symmetry around the Eu3+ emitter and distorting the matrix crystal of Y2O3, thus increasing the probability of intra‐4f electron transition. These results signify that the present rare‐earth doped DC luminescent materials are promising building blocks for assembly of high‐performance broadband solar‐blind UV detector. [ABSTRACT FROM AUTHOR]

Synchronous observations with similar illumination-observation and meteorological conditions are critical components of cross-calibration analysis. This study outlines data quality control criteria for obtaining the stable synchronous data needed for developing and evaluating a cross-calibration algorithm. With image data from the Visible Infrared Imaging Radiometer (VIIRS) and Medium Resolution Spectral Imager II (MERSI II), we developed a cross-calibration algorithm using 35 image pairs of four ocean gyres, and we evaluated the data using 11 image pairs of the global ocean. We found that our new algorithm provided well-calibrated MERSI II reflectance at the top-of-atmosphere. The coefficients of determination (R 2) were greater than 0.89, and the mean absolute percent difference (MAPD) varied from 1.13% to 8.37% in the visible bands, which was significantly superior to an algorithm developed from a data set constrained by existing data quality controls. When the satellite data were preprocessed with the new cross-calibration algorithm, the MERSI II instrument provided inter-mission remote sensing reflectance for the North Pacific Gyre that was consistent with the VIIRS instrument. Furthermore, we derived consistent estimates of remote sensing reflectance and backscattering coefficients (b b) from VIIRS and the cross-calibrated MERSI II reflectance data for four typically turbid coastal waters. The VIIRS b b coastal images had special distribution patterns, such as tongue-shaped plumes and mesoscale eddies, which accurately reappeared in the MERSI II images. The inter-mission MAPD values varied from 16%–24% for the coastal waters. This uncertainty level was much lower than the b b data quantified from the original MERSI II data with no cross-calibration. Our results suggest that our data quality control criteria provide good quality synchronous data for cross-calibration analysis. MERSI II could provide good ocean color products for oceanic communications after cross-calibration, even though the radiance calibration for the original MERSI II reflectance data are imperfect. • A new data quality controlling criterion is used to exclude unstable pixels in cross-calibration. • A cross-calibration method has been constructed for improving the imperfect MERSI II radiance. • The MERSI II instrument is able to provide the good ocean color products after cross-calibration. [ABSTRACT FROM AUTHOR]

Nickel-coated GH3535 alloy is suitable used for molten salt reactor at elevated temperature. However, coating failure caused by inter-diffusion is still problematic. In this study, tantalum and Ni Ta films were deposited as barriers between nickel coating and GH3535 alloy by magnetron sputtering, respectively. The diffusion behaviors of the coatings were investigated by micro-structure analysis and calculation of diffusion coefficient. The results indicate that a Ta barrier can inhibit the diffusion of Cr and Fe due to the formation of Ni 3 Ta phases, but Ni diffusion from the substrate to the barrier is promoted causing the formation of Kirkendall voids. However, a novel Ni Ta barrier exhibits excellent diffusion resistance for Cr, Fe, and Ni in the Ni/GH3535 system at 700 °C. • The diffusion resistance of the Ni Ta DB is significantly better than that of the Ta DB. • Ta DB can inhibit the diffusion of Cr and Fe, but Ni diffusion is promoted. • Ni Ta barrier exhibits excellent diffusion resistance for Cr, Fe, and Ni in the Ni/GH3535 system at 700 °C. [ABSTRACT FROM AUTHOR]

Chlorine evolution reaction (CER) is fundamental and critical for the conversion of Cl- to Cl 2 in a seawater environment. However, the selectivity and electrocatalytic activity of non-precious metal-based catalysts in CER remain unsatisfactory. It is still a challenge to develop cost-effective and efficient CER electrocatalysts that can be produced in large scale. Herein, we proposed a metal-organic framework (ZIF-67) as a precursor for the synthesis of Co 3 O 4 with a high specific surface area (SSA) and porous nano-sized. We then demonstrated for the first time that the porous nano-sized Co 3 O 4 has high chlorine precipitation activity and stability. The potential (vs. Ag/AgCl) increased slightly from 1.225 to 1.258 V within 24 h of electrocatalytic reaction, and the Faraday efficiencies were higher than 80% at different current densities, indicating significant stability and selectivity. CER mechanism of the Co 3 O 4 material under neutral seawater conditions was verified to be the Krishtalik mechanism by theoretical calculations. [Display omitted] • Using non-precious metal-based porous Co 3 O 4 material as a catalyst for CER. • CC/350 has excellent catalytic activity and selectivity in neutral seawater. • Verify the reaction mechanism of Co 3 O 4 under neutral seawater conditions by DFT. • Theoretically predicted that Co3+ in Co 3 O 4 is the active site of CER. • Experimentally explored the performance of MOFs related materials as CER catalysts. [ABSTRACT FROM AUTHOR]

Graphical abstract Three-dimensional hierarchical NiCo 2 O 4 /Ni 2 P electrodes have been successfully synthesized for advanced asymmetric supercapacitors. Highlights • Hierarchical NiCo 2 O 4 /Ni 2 P electrodes on nickel foam are rationally constructed. • This unique structure provides more electroactive sites for Faradaic reaction. • The NiCo 2 O 4 /Ni 2 P-30 electrode exhibits a high specific capacity of 2900 F g−1. • The assembled asymmetric supercapacitor can easily power 14 LEDs. Abstract Herein, a novel three-dimensional hierarchical NiCo 2 O 4 /Ni 2 P structure is successfully fabricated through a facile hydrothermal and subsequent electrodeposition process. One-dimensional Ni 2 P nanoneedles decorate on two-dimensional NiCo 2 O 4 nanosheets can effectively enhance the electrical conductivity and surface area of NiCo 2 O 4 to promote fast Faradaic reaction. The optimized NiCo 2 O 4 /Ni 2 P-30 electrode exhibits a high specific capacity of 2900 F g−1 at 0.008 A cm−2. Moreover, an asymmetric supercapacitor (ASC) is fabricated by using the NiCo 2 O 4 /Ni 2 P-30 as positive electrode and activated carbon as the negative electrode, the device achieves an excellent electrochemical property with the energy density of 40.7 W h kg−1 at 800 W kg−1. Besides, the as-assembled device also exhibits an excellent cycling performance of ∼92.0% of initial capacitance after 5000 cycles indicating its outstanding conductivity and structural stability. All of the results demonstrate that the hierarchical NiCo 2 O 4 / Ni 2 P composites are electrodes in energy storage application. [ABSTRACT FROM AUTHOR]

[Display omitted] • The reliability of DLTS simulation is confirmed by the nonlocal hybrid functional. • The electron–phonon coupling is included to describe the hot carrier nonradiative capture in the DLTS simulation. • The DLTS simulation is verified by the radiation experiments. Deep level transient spectroscopy (DLTS) is a crucial technique to characterize the defects in semiconductor devices. Within the framework of the state-of-the-art density functional theory (DFT), the simulation for experimental DLTS spectra is realized successfully with high accuracy and intrinsic physics in this work, of which the reliability is confirmed by nonlocal hybrid functional. The electron–phonon coupling is included to describe the thermal-activated behavior of the hot carrier nonradiative capture reflected by DLTS signal. In the case study, the divacancy in silicon is employed for the flow of DLTS calculation as a benchmark, of which the results are verified by our 40 MeV Si irradiation experiments on the NPN and PNP bipolar junction transistors and previous reports. The problem we can address is the identification of defect characterized in DLTS experiments. The realization of DLTS simulation would have a profound significance for understanding the underlying physics in experimental observations and be a powerful leverage to define defect nature in semiconductors. [ABSTRACT FROM AUTHOR]

• Soil water age is related to soil depth. • The water age of plant xylem and root zone soil is similar. • MTTs in a wet year are shorter than in a normal year. • The TTDs of some hydrological components vary between two hydrologic years. Transit times and the young water fraction (F yw , the proportion of the water younger than a certain age threshold, τ yw) can help characterize the hydrological behaviors within a catchment. Previous studies of water age have concentrated on individual catchment hydrological components, such as river water, groundwater, plant water or soil water, which hinders the dynamic linking of various hydrological components in the critical zone. In this study, the isotopic compositions of precipitation, soil water, xylem water, river water, and groundwater in a subtropical catchment in China were continuously monitored for two years. We found that the seasonal isotopic cycles of shallow soil water (0–60 cm), xylem water and river water had different attenuations and phase shifts relative to those of precipitation. There were no obvious seasonal isotopic cycles of deep soil water (60–130 cm) and groundwater. Additionally, the transit time distributions (TTDs) of soil water at the depth of 0–10 cm, xylem water and river water in the catchment varied between the wet year and normal year. With increasing depth, the mean transit times (MTTs) of soil water increased and the F yw decreased. For xylem water and soil water, the MTTs and F yw in the wet year were shorter and larger than those in the normal year, respectively. The river water consisted of a small proportion of fast flow components and a large proportion of slow flow components, with the young water accounting for 16% in the wet year and 21% in the normal year. Our results contribute to an improved understanding of water ages, flow paths and linkages of different hydrological components in the critical zone at the catchment scale. [ABSTRACT FROM AUTHOR]

The first total synthesis of (±)-latifolin has been accomplished in six steps and 47.8% overall yield. To understand the relative importance of phenolic OH and benzhydryl CH hydrogen on the antioxidant activity of latifolin, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and density functional theory (DFT) studies were carried out. On scavenging DPPH radical in ethanol, the activity of latifolin ( 1) bearing phenolic hydrogen is remarkably higher than analogue 10 bearing no phenolic hydrogen. Therefore, Phenolic hydrogen is responsible for latifolin's antioxidant activity rather than benzhydryl CH hydrogen. Furthermore, the 5-OH BDE is lower than 2′-OH and 7-CH BDEs by a DFT calculation, respectively. Based on theoretical results it is definitely concluded that the phenolic 5-OH plays a major role in the antioxidant activity of latifolin. [ABSTRACT FROM AUTHOR]

Little information is available about signaling response to magnesium toxicity (MgT) in plants. This study presents the first evidence that abscisic acid (ABA) and DELLA proteins participate in signaling response to long-term MgT in Arabidopsis thaliana (Landsberg erecta). Morphological, physiological, and molecular characteristics of a wild-type and two Arabidopsis mutants, ABA-insensitive mutant abi1-1 and constitutive elevated GA response mutant quadruple-DELLA (DELLA-Q: gai-t6 rga-t2 rgl1-1 rgl2-1) were monitored under MgT and normal magnesium conditions. Two weeks of MgT treatment strongly influenced the growth of young plants, but growth inhibition of the DELLA-Q and abi1-1 mutants was less than that of the wild-type plants. Exogenous ABA further inhibited the growth of the DELLA-Q mutants, similar to that of the wild-type. Both ABA and MgT also promoted DELLA protein RGA accumulation in the nuclei. Transcriptional analysis supported these results and revealed that a complex signaling network has responded to MgT in Arabidopsis. DELLA enhancement, which depends on ABI1, contributed to the remodeling growth and development of young seedlings. [ABSTRACT FROM AUTHOR]

• Hierarchical NiS@CoS nanotubes are designed with high supercapacitor performance. • NiS@CoS nanotubes exhibit high specific capacitance of 9.79 F cm−2 at 2 mA cm−2. • The capacity of NiS@CoS nanotubes remains 80.8% after 10000 at 20 mA cm−2. • The NiS@CoS-12//AC HSC device shows ultrahigh energy density of 0.63 mWh cm−2. • Formation of nanotubes reduces the dangling bonds at edges for improved stability. Unique structured electrodes with abundant surface area is imperative for developing high-performance supercapacitors. Herein, hollow hierarchical Ni 3 S 2 @Co 9 S 8 (NiS@CoS) nanotubes are rationally designed by a one-pot strategy, which demonstrate a substantial high active area. Accordingly, NiS@CoS nanotubes have exhibited promising electrochemical energy storage characteristics with high areal specific capacitance (9.79 F cm−2 at 2 mA cm−2) and excellent cycling stability (80.8% retention after 10000 at 20 mA cm−2). Furthermore, the hybrid supercapacitor (HSC) is designed with the NiS@CoS and active carbon (AC) as positive and negative electrodes, respectively. Remarkably, the HSC achieves ultrahigh energy density of 0.63 mWh cm−2 at a power density of 1.66 mW cm−2 (and 0.37 mWh cm−2 at 21.76 mW cm−2). This work offers a simple and effective approach to fabricate low-cost transition metal sulfides with great prospects in practical energy storage applications. [ABSTRACT FROM AUTHOR]

In this work, BiErFeO ( x = 0.05-0.25) nanoparticles were prepared by sol-gel method. X-ray diffraction and Raman analysis show that the structure of Er-doped BiFeO changes from rhombohedral lattice to orthorhombic one by increasing x. The remnant magnetization of the BiErFeO is significantly higher than those in BiFeO doped with non-magnetically rare-earth and it increases with increasing Er concentration. The enhanced magnetization was attributed to the suppression of the cycloidal spin structure by Er substitution and the ferromagnetic interaction between Fe and Er ions. The variation of the magnetization with temperature is also discussed. [ABSTRACT FROM AUTHOR]

Abstract: One-dimensional Tb3+-doped β-Ga2O3 nanofibers were prepared by a simple and cost-effective electrospinning process. Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Raman technique, and photoluminescence (PL) were used to characterize the electrospun nanofibers. FE-SEM results indicated that the diameters all of the nanofibers ranged from 100 to 300nm, and the lengths of nanofibers reached up to several millimeters. The XRD and Raman results showed that the Ga2O3 phase belongs to the monoclinic phase. Under ultraviolet excitation, the β-Ga2O3:Tb3+ samples showed green emission with the strongest peak at 550nm, corresponding to 5D4 → 7F5 transition of Tb3+ ions. The luminescence intensity had been further studied as a function of the doping concentration of Tb3+ in the β-Ga2O3 samples. [Copyright &y& Elsevier]

4-Hydroxycinnamic acid derivatives, including ferulic acid (FA) (1), sinapic acid (SA) (2) and caffeic acid (CA) (3), are widely distributed in the plant kingdom, and undergo oxidative cross-coupling leading to the corresponding dehydrodimers, trimers and even higher oligomers in plants. In order to evaluate the antioxidative ability of these 4-hydroxycinnamic acid derivatives and their oligomers, we synthesized 8-8'-bis-lactone-dimers (8-8-DiFA (4), 8-8-DiSA (5) and 8-8-DiCA (6)), as well as a new trimer (7), by the reaction of the corresponding monomers (1-3) with Ag2O in methanol, and assayed their free radical-scavenging activity by the reaction with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·). It was found that CA (3) and 8-8'-DiCA (6) bearing o-dihydroxyl groups exhibited significantly higher radical-scavenging activity than those bearing no such groups, and oxidative coupling of CA (3) resulted in remarkable enhancement in the activity. [ABSTRACT FROM AUTHOR]