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Industrial micron-size hexahydro-1,3,5-trinitro-1,3,5-triazine (m-RDX) has been widely used in RDX-based polymer-bonded explosives (PBX). However, m-RDX results in poor mechanical properties and adhesive properties of RDX-based PBX (m-RDX–PBX). Nano-RDX (n-RDX) has a small particle size and a large specific surface area, which provides a larger contact area with the polymer system. Thus, the porosity and compressive properties of PBX are improved if n-RDX is used in RDX-based PBX (RDX–PBX). In this study, m-RDX and n-RDX are used in RDX–PBX. The microstructure, component content, compressive properties, sensitivity properties, and detonation properties of RDX–PBX are investigated. The results show that n-RDX can make RDX–PBX more compact than m-RDX. The strain of n-RDX-based PBX (n-RDX–PBX) is increased by 39.7% as compared to that of m-RDX–PBX. Meanwhile, the content of each component in n-RDX–PBX is consistent with that of the formula. The sensitivity of n-RDX–PBX is lower as compared to that of m-RDX–PBX, whereas the detonation velocity, detonation pressure, and detonation heat of n-RDX–PBX are equivalent to those of m-RDX–PBX. [ABSTRACT FROM AUTHOR]

Midvein is an important structure of the upright leaf of rice, and its normal development is essential to the formation of a common plant type of rice (Oryza sativa L.). To reveal the effect of midvein deficiency on photosynthesis-related characteristics, leaf microstructure, and vein characteristics, the photosynthetic features between the midvein-deficient mutant dl-14 and wild-type Huanghuazhan plants were analyzed. The results indicated that the midvein area of the dl-4 mutant lacked large intercellular space and instead it was filled with mesophyll cells. Moreover, the vein density of the dl-14 mutant was significantly higher than that in cv. Huanghuazhan. Chlorophyll (Chl) a, Chl b, and carotenoid content were markedly elevated in dl-14. In terms of photosynthetic characteristics, we observed that under high irradiance and high CO2 concentration, the net photosynthetic rate of dl-14 plants was significantly higher than that of Huanghuazhan plants, but its water use efficiency was significantly lower. In addition, several major photosynthetic parameters, including characteristics of chlorophyll fluorescence (the efficiency of excitation capture of open PS II center, photochemical quenching, effective quantum yield of PS II photochemistry, and electron transfer rate) were significantly higher in dl-14 plants compared to Huanghuazhan plants, but the nonphotochemical quenching of dl-14 mutant was significantly lower than that of Huanghuazhan. These findings indicate that the dl-14 mutant has higher vein density, stronger photon conversion ability, and weaker radiation dissipation ability. This study can provide theoretical support for breeders to use the midvein-deficient mutant. [ABSTRACT FROM AUTHOR]

Midvein is an important structure of the upright leaf of rice, and its normal development is essential to the formation of a common plant type of rice (Oryza sativa L.). To reveal the effect of midvein deficiency on photosynthesis-related characteristics, leaf microstructure, and vein characteristics, the photosynthetic features between the midvein-deficient mutant dl-14 and wild-type Huanghuazhan plants were analyzed. The results indicated that the midvein area of the dl-4 mutant lacked large intercellular space and instead it was filled with mesophyll cells. Moreover, the vein density of the dl-14 mutant was significantly higher than that in cv. Huanghuazhan. Chlorophyll (Chl) a, Chl b, and carotenoid content were markedly elevated in dl-14. In terms of photosynthetic characteristics, we observed that under high irradiance and high CO2 concentration, the net photosynthetic rate of dl-14 plants was significantly higher than that of Huanghuazhan plants, but its water use efficiency was significantly lower. In addition, several major photosynthetic parameters, including characteristics of chlorophyll fluorescence (the efficiency of excitation capture of open PS II center, photochemical quenching, effective quantum yield of PS II photochemistry, and electron transfer rate) were significantly higher in dl-14 plants compared to Huanghuazhan plants, but the nonphotochemical quenching of dl-14 mutant was significantly lower than that of Huanghuazhan. These findings indicate that the dl-14 mutant has higher vein density, stronger photon conversion ability, and weaker radiation dissipation ability. This study can provide theoretical support for breeders to use the midvein-deficient mutant. [ABSTRACT FROM AUTHOR]

We investigate the magnetoelectric effect in Sr2CoGe2O7, which has a two-dimensional magnetic interaction between Co ions in the ab plane. This compound shows a weak magnetism and field-induced magnetic transition below the temperature of 7K. It does not exhibit electric polarization under zero magnetic field. However, by applying an external magnetic field, the electric polarization is induced around its Néel temperature and increases with increasing magnetic field. The induced electric polarization in Sr2CoGe2O7 is almost two orders of magnitude smaller than that of Ba2CoGe2O7. This result suggests that the different ionic radius of the strontium and the barium anion plays a key role in determining the property of electric polarization. The origins of electric polarization and magnetoelectric effect are discussed. [ABSTRACT FROM AUTHOR]

The irradiation of a target with high laser intensity can lead to self-generation of an intense magnetic field (B-field) on the target surface. It has therefore been suggested that the sheath-driven acceleration of high-energy protons would be significantly hampered by the magnetization effect of this self-generated B-field at high enough laser intensities. In this paper, particle-in-cell simulations are used to study this magnetization effect on sheath-driven proton acceleration. It is shown that the inhibitory effect of the B-field on ion acceleration is not as significant as previously thought. Moreover, it is shown that the magnetization effect plays a relatively limited role in high-energy proton acceleration, even at high laser intensities when the mutual coupling and competition between self-generated electric (E-) and B-fields are considered in a realistic sheath acceleration scenario. A theoretical model including the v × B force is presented and confirms that the rate of reduction in proton energy depends on the strength ratio between B- and E-fields rather than on the strength of the B-field alone, and that only a small percentage of the proton energy is affected by the self-generated B-field. Finally, it is shown that the degraded scaling of proton energy at high laser intensities can be explained by the decrease in acceleration time caused by the increased sheath fields at high laser intensities rather than by the magnetic inhibitory effect, because of the longer growth time scale of the latter. This understanding of the magnetization effect may pave the way to the generation of high-energy protons by sheath-driven acceleration at high laser intensities. [ABSTRACT FROM AUTHOR]

Insulin-like growth factor binding protein 5 (IGFBP5) is broadly bioactive, but its role in osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs) remains to be clarified. Here, we demonstrated that IGFBP5 expression was markedly increased during the early osteogenic differentiation of hMSCs. We then over-expressed and knocked down this gene in hMSCs and evaluated the impact of manipulation of IGFBP5 expression on osteogenic differentiation based upon functional assays, ALP staining, and expression of osteogenic markers. Together, these analyses revealed that IGFBP5 over-expression enhanced early osteogenic differentiation, as evidenced by increased ALP staining and osteogenic marker induction, whereas knocking down this gene impaired the osteogenic process. Over-expression of IGFBP5 also markedly bolstered the extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation level, while IGFBP5 knockdown suppressed this signalling activity. We additionally compared the impact of simultaneous IGFBP5 overexpression and ERK1/2 inhibitor treatment to the effect of IGFBP5 over-expression alone in these hMSCs, revealing that small molecule-mediated EKR1/2 inhibition was sufficient to impair osteogenic differentiation in the context of elevated IGFBP5 levels. These findings indicated that IGFBP5 drives the early osteogenic differentiation of hMSCs via the ERK1/2 signalling pathway. Our results offer value as a foundation for future efforts to study and treat serious bone-related diseases including osteoporosis. [ABSTRACT FROM AUTHOR]

In order to address the present challenges in generating a sizeable Dirac-cone gap for monolayer graphene, primarily due to the robust symmetry dependency and protection, we intentionally investigate ternary graphene lattices by pairing IIIA–VA atom substitution. We demonstrate by first-principles calculations an ordered boron-phosphorus codoped graphene (C4BP) monolayer realizing a sizable ∼0.24 eV and simultaneously strain-tunable-reclosed quasi Dirac-cone gap. The peculiar band topology is attributed to unique symmetry breaking of the primary graphene lattice by the ordered doping coordination and resulting electronic couplings, which also endow the material with appealing properties comparable to the parent graphene, e.g., ultrahigh carrier mobility (>105 cm2 V−1 s−1) and Fermi velocity (>0.8 × 106 m s−1) as well as a topologically nontrivial phase but with a more appreciable SOC gap. The predicted high dynamic, thermal and energetic stabilities support its experimental viability. Our result opens up a new branch for band engineering of versatile graphene. [ABSTRACT FROM AUTHOR]

In order to address the present challenges in generating a sizeable Dirac-cone gap for monolayer graphene, primarily due to the robust symmetry dependency and protection, we intentionally investigate ternary graphene lattices by pairing IIIA–VA atom substitution. We demonstrate by first-principles calculations an ordered boron-phosphorus codoped graphene (C4BP) monolayer realizing a sizable ∼0.24 eV and simultaneously strain-tunable-reclosed quasi Dirac-cone gap. The peculiar band topology is attributed to unique symmetry breaking of the primary graphene lattice by the ordered doping coordination and resulting electronic couplings, which also endow the material with appealing properties comparable to the parent graphene, e.g., ultrahigh carrier mobility (>105 cm2 V−1 s−1) and Fermi velocity (>0.8 × 106 m s−1) as well as a topologically nontrivial phase but with a more appreciable SOC gap. The predicted high dynamic, thermal and energetic stabilities support its experimental viability. Our result opens up a new branch for band engineering of versatile graphene. [ABSTRACT FROM AUTHOR]

Different types of effective neural network structures have been developed, including the recurrent neural networks (RNNs), concurrent neural networks (CNNs), among others. The TrumpetNet was recently proposed by the leading author for creating two-way deepnets using physics-law-based models, such as finite element method (FEM) and smoothed FEM or S-FEM. The unique feature of the TrumpetNet is the effectiveness of both forward and inverse problems, by design a desired net architecture. Most importantly, solutions to inverse problems can be analytically derived in explicit formulae for the first time. This work presents a novel TubeNet designed for inverse problems, by designing a simple but special tubular architecture. The TubeNet is a simplified TrumpetNet, and hence it is found easier to apply. It uses the principal component analysis (PCA) to reduce the dimensionality of the "measurement" data, which allows one to select the desired number of major principal components to match with the number of neurons in a layer in the TubeNet. Intensive studies and analyses were conducted to examine the proposed TubeNet, using solid mechanics problem considering material property as parameters to be inversely identified. In this work, we successfully inversely identified up to eight parameters for idealized composite laminates, through explicit formulas, termed as direct-weights-inversion (DWI) approach, which is a chain of matrix inversions for the weight matrices of the network layers. The proposed TubeNet concept can fundamentally change the way in which inverse problems in various fields of studies are dealt with. It is a breakthrough in dealing with inverse problem that are inherently difficult to solve. [ABSTRACT FROM AUTHOR]

The optical constants of tantalum pentoxide (Ta2O5) are determined in a broad spectral region from the visible to the far infrared. Ta2O5 films of various thicknesses from approximately 170 to 1600 nm are deposited using reactive magnetron sputtering on Si substrates. X-ray diffraction shows that the as-deposited films are amorphous, and annealing in air at 800 °C results in the formation of nanocrystalline Ta2O5. Ellipsometry is used to obtain the dispersion in the visible and near-infrared. Two Fourier-transform infrared spectrometers are used to measure the transmittance and reflectance at wavelengths from 1 to 1000 μm. The surface topography and microstructure of the samples are examined using atomic force microscopy, confocal microscopy, and scanning electron microscopy. Classical Lorentz oscillators are employed to model the absorption bands due to phonons and impurities. A simple model is introduced to account for light scattering in the annealed films, which contain micro-cracks. For the unannealed samples, an effective-medium approximation is used to take into account the adsorbed moisture in the film and a Drude free-electron term is also added to model the broad background absorption. [ABSTRACT FROM AUTHOR]

A reverse Monte Carlo (RMC) method is developed to obtain the energy loss function (ELF) and optical constants from a measured reflection electron energy-loss spectroscopy (REELS) spectrum by an iterative Monte Carlo (MC) simulation procedure. The method combines the simulated annealing method, i.e., a Markov chain Monte Carlo (MCMC) sampling of oscillator parameters, surface and bulk excitation weighting factors, and band gap energy, with a conventional MC simulation of electron interaction with solids, which acts as a single step of MCMC sampling in this RMC method. To examine the reliability of this method, we have verified that the output data of the dielectric function are essentially independent of the initial values of the trial parameters, which is a basic property of a MCMC method. The optical constants derived for SiO2 in the energy loss range of 8-90 eV are in good agreement with other available data, and relevant bulk ELFs are checked by oscillator strength-sum and perfect-screening-sum rules. Our results show that the dielectric function can be obtained by the RMC method even with a wide range of initial trial parameters. The RMC method is thus a general and effective method for determining the optical properties of solids from REELS measurements. [ABSTRACT FROM AUTHOR]

In this paper, the generation of relativistic electron mirrors (REM) and the reflection of an ultra-short laser off the mirrors are discussed, applying two-dimension particle-in-cell simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapid expansion. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads to the resonance between laser and REM. The reflected radiation near this interval and corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, a certain part of the reflected field could be selectively amplified or depressed, leading to the selective adjustment of the corresponding spectra. [ABSTRACT FROM AUTHOR]

The paper presents an explicit matrix algorithm to solve the problem of an elastic wedge with three loaded surfaces. The algorithm makes use of a recently published concept of transformation matrix, by which the original surface loads are converted to equivalent loads in half-space. The three loaded edges are considered simultaneously. The developed algorithm is used to study the effects of two free edges of a steel block and tapered rollers with different contact angles. The two load-free edges can substantially increase deformation if the two edges are close in distance. The results of the tapered roller simulation show that deformation is considerably sensitive to the contact angle of the tapered roller. The largest deformation appears at the big end of the roller. Furthermore, empirical formulae for correction factors for the calculation of block or quarter-space deformation based on half-space solutions are summarized. [ABSTRACT FROM AUTHOR]

Ion source development over the last 20 years at the IMP is reviewed. For versatile purposes, several types of ion sources have been involved in the research and development work at the IMP, i.e., the highly charged ECR (Electron Cyclotron Resonance) ion source, intense microwave ion source or the 2.45 GHz intense beam ECR ion source, and laser ion source (LIS). In the development of ECR ion sources, SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou), Lanzhou ECR ion source, and Lanzhou all permanent magnet ECR ion source series have been made, which can cover the operation microwave frequency range of 10–28 GHz. The LIS with an Nd:YAG laser with a maximum output energy of 8 J in 8 ns pulse duration has been developed for very intense short pulse ion beams from solid materials such as C, Ti, Ni, Ag, and so on. Microwave ion sources have been built to produce intense pulsed or direct current beams from several mA to 100 mA for either high intensity accelerators or applications. This paper will give an overview of the high intensity ion source development at the IMP, especially on the recent progress and new results, such as the status of the fourth generation ECR ion source (first fourth generation ECR ion source), the production of recorded highly charged ion beams with SECRAL sources, key technology research studies, and so on. [ABSTRACT FROM AUTHOR]

Cold stress is one major threats to field crops. The cold tolerant ability is a key limiting factor for the popularization of peanut (Arachis hypogaea L.) in cold areas. Our previous research showed three key metabolic change time points of peanut buds in response to low temperature. The present study applied iTRAQ proteomic to further quantify differentially expressed proteins in three key metabolic change time points. A total of 2684 non-redundant proteins and 333 differentially expressed proteins across the three cold stress treatment points were identified. The results enrich the cold stress regulation network and provide useful information for further improving the ability of peanut under cold stress. [ABSTRACT FROM AUTHOR]

Repair is now increasingly used for damaged structures due to its distinguished advantages in prolonging the service life of structures, substantial saving in materials, and preservation of related crucial resources. This work presents a novel filling-in repair procedure for localized damages in panel structures, and conducts a series of theory and numerical studies to examine the repair effects in terms of stress concentration. It aims providing some fundamental understandings important in the design of repairing procedures for effective filling-in repairs to mitigate stress concentrations. First, the damaged zone (or cracks) is "cut-off" by simply drilling a hole through the panel to remove possible stress singularity. The hole is then filled-in with a circular patch of slightly smaller diameter made of similar material of the panel using adhesives. Stress concentration is then investigated to reveal the possible ranges of the stress concentration factors (SCF), through both analytical and numerical means using finite element (FE) models. The repair effects are then examined for repaired plates with filled-in holes in terms of SCF reduction, comparing with plates with open-holes. Both aluminum and composite plates are studied, and the filling-in repairs are carried out using epoxy adhesives. It is found that the SCF increases with the adhesive thickness, decreases with hole radius and Young's modulus of adhesives. Parametric studies are performed to produce two-stage curve-fitted formulae for SCF predictions from given hole radius, physical properties and thickness of the adhesive layer, which are useful for the design and assessment of the repairs, leading to a prolonged life of services of structures. [ABSTRACT FROM AUTHOR]

Simulation of contrast formation in Auger electron imaging of surfaces is helpful for analyzing scanning Auger microscopy/microanalysis (SAM) images. In this work, we have extended our previous Monte Carlo model and the simulation method for calculation of scanning electron microscopy (SEM) images to SAM images of complex structures. The essentials of the simulation method are as follows. (1) We use a constructive solid geometry modeling for a sample geometry, which is complex in elemental distribution, as well as in topographical configuration and a ray-tracing technique in the calculation procedure of electron flight steps that across the different element zones. The combination of the basic objects filled with elements, alloys, or compounds enables the simulation to a variety of sample geometries. (2) Sampled Auger signal electrons with a characteristic energy are generated in the simulation following an inner-shell ionization event, whose description is based on the Castani’s inner-shell ionization cross section. This paper discusses in detail the features of simulated SAM images and of line scans for structured samples, i.e., the objects embedded in a matrix, under various experimental conditions (object size, location depth, beam energy, and the incident angle). Several effects are predicted and explained, such as the contrast reversion for nanoparticles in sizes of 10–60 nm, the contrast enhancement for particles made of different elements and wholly embedded in a matrix, and the artifact contrast due to nearby objects containing different elements. The simulated SAM images are also compared with the simulated SEM images of secondary electrons and of backscattered electrons. The results indicate that the Monte Carlo simulation can play an important role in quantitative SAM mapping. [ABSTRACT FROM AUTHOR]

Radiative energy transfer at nanoscale distances can exceed that of blackbody radiation by several orders of magnitude due to photon tunneling and the excitation of surface polaritons. While significant progress has been made recently in understanding near-field thermal radiation, an outstanding question remains as whether there exists an upper limit of near-field radiation for arbitrarily selected material properties at finite separation distances. We investigate the maximum achievable radiative heat flux between two parallel plates separated by a vacuum gap from 0.1 to 100 nm. By assuming a frequency-independent dielectric function and introducing a cutoff parallel wavevector component, we find that the ideal dielectric function for the two media that will maximize the near-field radiative transfer is -1+iδ, where δ is the imaginary part. For vacuum gaps greater than 1 nm, the near-field heat transfer peaks when δ<1, while at subnanometer gaps, the peak in the energy transfer shifts toward larger values of δ. The determination of the maximum radiative flux at nanometer distances will benefit emerging applications of near-field radiation for energy harvesting and nanothermal manufacturing. [ABSTRACT FROM AUTHOR]

A large number of recent publications dealt with enhanced emission properties of micro/nanostructures by the excitation of surface plasmon or phonon polaritons. Some used grating structures to demonstrate coherent thermal emission in a narrow spectral band and towards a well-defined direction. Others suggested that planar layers could also be used to achieve coherent emission. In the present paper, we describe two alternative designs with fewer layers for the application as coherent emission sources in planar multilayer structures. One design is a composite of several unit cells of one-dimensional photonic crystal atop a highly reflective material. Coherent emission can be obtained by the excitation of surface waves between the photonic crystal and the reflector. The other design employs a Fabry-Pérot resonance cavity constructed by coating a dielectric layer onto the reflector and then a thin metallic film on the dielectric layer. When standing waves exist in the cavity, the emissivity plots show sharp spectral peaks and narrow angular lobes. By optimizing the film thicknesses, a close-to-unity emissivity can be achieved from the proposed structures. The theoretical predictions are supported by the measured spectral reflectance from fabricated samples. [ABSTRACT FROM AUTHOR]

Adaptive capacity has become the focus of current research on climate change. A complete set of methods to assess the adaptive capacity for Beijing water resources was established in this study. Risk factors for water resources were identified by overlapping climate change, urbanization issues, and urban water resources, and a three-dimensional framework comprising 12 indicators specific to each risk factor was built to assess the adaptive capacity of the water resource systems. These three dimensions represent the three pillars of a sustainable water resource system: water supply, water demand, and water quality. An analytic hierarchy process was used to determine the weight for each indicator. Then a fuzzy version of the technique for order preference by similarity to an ideal solution was applied to calculate the ranking for the 11 districts in Beijing and quantify the adaptive capacity for water resources in these areas. The fuzzy approach results revealed that three indicators are key: comprehensive management capabilities for water supply, control capability for water demand, and management capabilities for water quality. Finally, adaptability proposals are proposed in accordance with the ranking results obtained. [ABSTRACT FROM AUTHOR]

With the forthcoming laser intensities (I ≥ 1023 W/cm2), synchrotron radiation in a laser-plasma interaction has attracted particular interest because it can lead to an extremely bright source of γ-rays. Here, a scheme to generate a bright γ-ray pulse with high efficiency is proposed and numerically demonstrated. Using a circularly polarized (CP) laser pulse impinged on a thin foil, a relativistic flying plasma layer is formed. With another counterpropagating CP pulse colliding with the flying layer, it is found that the electrons are efficiently accelerated in the longitudinal direction by the space-charge field. The energetic electrons interact with the counterpropagating CP pulse, producing ultra-brilliant (∼1024 photons/s/mm2/mrad2/0.1%BW) highly dense (∼270nc) femtosecond (∼5 fs) γ-ray pulses. At a moderate laser intensity of 4 × 1022 W/cm2, the fraction of laser energy transferred into the γ-ray pulse is as high as 10%, which is comparable to that previously predicted for an order of magnitude higher in laser intensity. The enhanced γ-photon emission might pave the way for its potential applications in the near future. [ABSTRACT FROM AUTHOR]

Near surface air temperature (NSAT) is a primary descriptor of terrestrial environment conditions. The availability of NSAT with high spatial resolution is deemed necessary for several applications such as hydrology, meteorology and ecology. In this study, a regression-based NSAT mapping method is proposed. This method is combined remote sensing variables with geographical variables, and uses geographically weighted regression to estimate NSAT. The altitude was selected as geographical variable; and the remote sensing variables include land surface temperature (LST) and Normalized Difference vegetation index (NDVI). The performance of the proposed method was assessed by predict monthly minimum, mean, and maximum NSAT from point station measurements in China, a domain with a large area, complex topography, and highly variable station density, and the NSAT maps were validated against the meteorology observations. Validation results with meteorological data show the proposed method achieved an accuracy of 1.58°C. It is concluded that the proposed method for mapping NSAT is very operational and has good precision. [ABSTRACT FROM AUTHOR]

Here a compact three orthogonal planes high-energy electron radiography system was proposed. One of the critical technologies, the ultra-fast beam bunches split from the bunch train are studied. The separated bunches could be transported to the three orthogonal planes of the target for dynamic radiography diagnostics. The key elements of the ultra-fast bunches split system are transverse deflecting cavity (TDC) and the twin septum magnet (TSM). The principle of TDC and TSM are briefly introduced. An example of the beam bunches split system for test experiment (40 MeV electron beam) with TDC and TSM is designed and studied by particle-tracking simulation and it confirms this method is valid and feasible. Especially with TSM, a compact three orthogonal planes radiography system can be realized. The evolution of the beam parameters along the beam line from simulation are investigated. The detailed design of the beam split system and beam dynamics simulation study are presented in this paper. [ABSTRACT FROM AUTHOR]

Strong coupling stimulated Brillouin backscattering (sc-SBS) in plasma is potentially an efficient method of amplifying laser pulses to reach exawatt powers. Here, we report on a new regime of brillouin-based plasma amplification, producing an amplified pulse with a duration of 5 fs and unfocused intensity of 6x1017 W/cm2. The results are obtained from 2D particle-in-cell simulations, using two circularly polarized pump and seed pulse with Gaussian transverse profile, both at an intensity of 2.74x1016 W/cm2, counter-propagating in a 0.3nc plasma. The significant compression of amplified seed is achieved as a result of sc-SBS amplification as well as additional compression by the interplay between self-phase modulation and negative group delay dispersion. We show that the amplified seed retains high beam qualities since the filamentation can be prevented due to the fast compression. This scheme may pave the way for few-cycle laser pulses to reach exawatt or even zetawatt regime. [ABSTRACT FROM AUTHOR]

Resonant acceleration of electrons by a laser in the background of an extra longitudinal magnetic field is investigated analytically and numerically. The resonant condition is independent of laser intensity, and when satisfied, the energy gain is proportional to $a_0^2 $ and the square of phase difference. This process is mainly limited by the magnitude and spatial size of the extra magnetic field. Under the laboratory conditions, simulation results show that a monoenergetic and collimated electron bunch can still be obtained in ~ GV/cm scale, which sheds a light on the vacuum table-top laser-driven electron accelerators. [ABSTRACT FROM PUBLISHER]

Broadband absorption is needed for a wide spectrum of applications such as solar–thermal conversion, radiative cooling, and photodetection. In this work, we theoretically show that trapezoidal gratings made of a natural hyperbolic material on a metal substrate can be used to achieve omnidirectional perfect absorption in a relatively broad spectral region. Hexagonal boron nitride (hBN) is taken as a mid-infrared polar material with hyperbolic characteristic in the wavelength region from 6.2 to 7.3 μm. The anisotropic rigorous-coupled wave analysis is used to calculate the absorptance as well as the local power dissipation and field distributions. The main mechanism for the broadband perfect absorption is elucidated by considering the slow-light effect in a hyperbolic waveguide, which can trap the incident light of different wavelengths in different regions of the trapezoid. The spectral range and bandwidth of near perfect absorption can be adjusted within the hyperbolic range of the material by changing the shape of the trapezoid. Moreover, the substrate can play a role on the reflectance and transmittance of the structure for the wavelengths that do not support the slow-light effect. Similar designs can be applied to other hyperbolic materials to achieve perfect absorption in various wavelength regions. [ABSTRACT FROM AUTHOR]

Saccharomyces uvarum is a good wine yeast species that may have great potential for the future. However, sulfur tolerance of most S. uvarum strains is very poor. In addition there is still little information about the SSU1 gene of S. uvarum, which encodes a putative transporter conferring sulfite tolerance. In order to analyze the function of the SSU1 gene, two expression vectors that contained different SSU1 genes were constructed and transferred into a sulfite-tolerant S. uvarum strain, A9. Then sulfite tolerance, SO2 production, and PCR, sequencing, RT-qPCR and transcriptome analyses were used to access the function of the S. uvarum SSU1 gene. Our results illustrated that enhancing expression of the SSU1 gene can promote sulfite resistance in S. uvarum, and an insertion fragment ahead of the additional SSU1 gene, as seen in some alleles, could affect the expression of other genes and the sulfite tolerance level of S. uvarum. This is the first report on enhancing the expression of the SSU1 gene of S. uvarum. [ABSTRACT FROM AUTHOR]

An instrument used for measuring multiple scintillators' light output and energy resolution was developed. The instrument consisted of a light sensor array which was composed of 64 discrete SiPMs (Silicon Photomultipliers), a corresponding individual channel readout electronics system, and a data processing algorithm. A Teflon grid and a large interval between adjacent SiPMs were employed to eliminate the optical cross talk among scintillators. The scintillators' light output was obtained by comparing with a reference sample with known light output. Given the SiPM temperature dependency and the difference among each SiPM, a temperature offset correction algorithm and a non-uniformity correction algorithm were added to the instrument. A positioning algorithm, based on nine points, was designed to evaluate the performance of a scintillator array. Tests were performed to evaluate the instrument's performance. The uniformity of 64 channels for light output measurement was better than 98%, the stability was better than 98% when temperature varied from 15 °C to 40 °C, and the nonlinearity under 511 keV was better than 2%. This instrument was capable of selecting scintillators and evaluating the packaging technology of scintillator arrays with high efficiency and accuracy. [ABSTRACT FROM AUTHOR]

A scheme for the improvement of proton beam quality by the optimized dragging field from the interaction of ultraintense laser pulse with a complex double-layer target is proposed and demonstrated by one-dimensional particle-in-cell (Opic1D) simulations. The complex double-layer target consists of an overdense proton thin foil followed by a mixed hydrocarbon (CH) underdense plasma. Because of the existence of carbon ions, the dragging field in the mixed CH underdense plasma becomes stronger and flatter in the location of the proton beam than that in a pure hydrogen (H) underdense plasma. The optimized dragging field can keep trapping and accelerating protons in the mixed CH underdense target to high quality. Consequently, the energy spread of the proton beam in the mixed CH underdense plasma can be greatly reduced down to 2.6% and average energy of protons can reach to 9 GeV with circularly polarized lasers at intensities 2.74 × 1022 W/cm2. [ABSTRACT FROM PUBLISHER]

Eutrophication is a major environmental issue that mankind is facing today as a result of rapid development. To reduce the eutrophication problem, we are testing an innovative artificial floating islands (AFIs) approach. AFIs include aquatic plants composed of emergent and floating macrophytes. In this experimental approach, two aquatic plants were selected to compare with the control group in order to evaluate the capacity of AFIs. These two emergent macrophytes were evaluated for a 40-day timeframe to examine their ability to purify waste water. The results showed that an AFI with purple loosestrife (Lythrum salicariaLinn.) and one with yellow-flowered iris (Iris wilsonii) have a strong ability to remove nitrogen, phosphorus, and other pollutants from water bodies. The pollutant removal rates of the AFIs with purple loosestrife and yellow-flowered iris were almost over 50%. The chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) removal rates of the AFI with purple loosestrife were about 75%, 57%, 71%, respectively. At the same time, the COD, TN, and TP removal rates of the AFI with yellow-flowered iris were 60%, 49%, and 68%, respectively. AFIs with aeration are also a good way to remove pollutants. This study reveals that AFIs can be incorporated into wetlands to reduce the effects of water contamination and help strengthen wetland restoration. [ABSTRACT FROM AUTHOR]

Laser amplification in plasma, including stimulated Raman scattering amplification and strongly coupled stimulated Brillouin scattering (sc-SBS) amplification, is very promising to generate ultrahigh-power and ultrashort laser pulses. But both are quite complex in experiments: at least three different laser pulses must be prepared; temporal delay and spatial overlap of these three pulses are difficult. We propose a single pulse compression scheme based on sc-SBS in plasma. Only one moderately long laser is applied, the front part of which ionizes the gas to produced plasma, and gets reflected by a plasma mirror at the end of the gas channel. The reflected front quickly depletes the remaining part of the laser by sc-SBS in the self-similar regime. The output laser is much stronger and shorter. This scheme is at first considered theoretically, then validated by using 1D PIC simulations. [ABSTRACT FROM AUTHOR]

Aim 5-Aminosalicylic acid is the first-line drug for mild to moderate ulcerative colitis ( UC). The most commonly used 5-aminosalicylic acid is mesalamine. Several systematic reviews have demonstrated that mesalamine is effective in inducing and maintaining remission. Efficacy, safety and adherence to once daily ( OD) and multiple daily ( MD) dosing of mesalamine for the induction and maintenance of remission in mild to moderate UC were systematically reviewed and compared. Method PubMed, Embase and the Cochrane Central Register of Controlled Trials were searched from inception to November 2014. Only randomized controlled trials were considered eligible. STATA software (version 12.0) was used to calculate the pooled risk ratios with 95% confidence interval. Results Seventeen randomized studies containing 5439 patients were identified. No significant differences were noted in comparisons between OD and MD dosing for maintenance and induction of remission. No significant differences were noted in rates of medication adherence or adverse events between OD and MD dosing. With regard to mesalamine suppository, no significant differences were noted for comparisons between dosing regimens and adverse events for induction of remission. Conclusion OD dose of mesalamine is as effective and safe as MD doses for the induction and maintenance treatment of mild to moderate UC. OD mesalamine given as a suppository can attain the same effect and safety as MD mesalamine in inducing remission of mild to moderate ulcerative colitis. [ABSTRACT FROM AUTHOR]

Insulator to metal phase transitions driven by external electric field are one of the hottest topics in correlated oxide study. While this electric triggered phenomena always mixes the electric field switching effect and joule thermal effect together, which are difficult to clarify the intrinsic mechanism. In this paper, we investigate the dynamical process of voltage-triggered metal-insulator transition (MIT) in a VO2 crystal film and observe the temperature dependence of the threshold voltages and switching delay times, which can be explained quite well based on a straightforward joule thermal model. By conducting the voltage controlled infrared transmittance measurement, the delayed infrared transmission change is also observed, further confirming the homogeneous switching process for a large-size film. All of these results show strong evidences that joule thermal effect plays a dominated role in electric-field-induced switching of VO2 crystal. [ABSTRACT FROM AUTHOR]

The article focuses on determining age of freshwater fish Abramis brama from Irtysh River in China by counting increase in its otoliths, and relationships of otolith dimensions with fish length. Topics discussed include otolith weight (OW) analysis helping in determine age of A. brama, isometric growth between the OW and fish standard length/age, lack of food resources responsible for slow growth rate, and suggestion on avoiding fishing during spawning season to enhance their growth.

The electrochemical behavior and oxide film structure of the weld of 316L/52M/A508 dissimilar metal welded joints were investigated via scanning electron microscopy (SEM), potentiodynamic polarization measurements, electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS). The electrochemical measurements revealed that the weld materials could be arranged in descending order of protectiveness of the oxide film formed on their surface; that is, Alloy52Mw>Alloy52Mb>C52M>C308. The results of EIS and XPS analyses showed that the oxide films formed on these materials were duplex-structured; this duplex structure consisted of a Cr-rich (in 52M nickel-based weld materials) or Cr/Fe-rich (in C308 stainless steel weld materials) inner layer and a Ni/Fe-rich (in 52M nickel-based weld materials) or Fe-rich (in 308 stainless steel weld materials) porous outer layer. [ABSTRACT FROM AUTHOR]

Excitation of surface plasmons enables super-Planckian thermal radiation far beyond the blackbody limit. By patterning a single layer of graphene sheet into ribbons, the closed circular dispersion of graphene plasmons is opened to become hyperbolic, leading to broadband singularities of density of states. Extremely high-k evanescent waves can now couple with hyperbolic graphene plasmons. Consequently, a giant enhancement of the near-field radiative heat flux, by more than one order of magnitude, is demonstrated in this study using rigorous numerical simulations. The findings may open promising pathways for highly efficient thermal management, energy harvesting, and subwavelength thermal imaging. [ABSTRACT FROM AUTHOR]