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The aim of this study was to investigate the antioxidative and neuroprotective activities of total flavonoids from sea buckthorn (Hippophae rhamnoides L.) (TFH). Results indicated that TFH possessed DPPH radicals, hydroxyl radicals and superoxide anions scavenging activities. The neuroprotective potential was assessed with acetylcholinesterase (AChE) and monoamine oxidase A (MAO-A). The inhibition rates of AChE and MAO-A by 50 μg/ml TFH were 75.85 and 51.22%, respectively. The in vivo antioxidative and neuroprotective potential of TFH were explored in Caenorhabditis elegans. In the longevity assay, TFH (50 μg/ml) significantly increased the lifespan of wild-type C. elegans (29.40%). In the hydrogen peroxide-induced oxidative stress challenge, the antioxidant capacity of TFH-treated wild-type C. elegans was significantly enhanced. The C. elegans mutant strain CL4176 was used to study the neuroprotective effect of TFH in vivo. Results showed that TFH significantly delayed paralysis in C. elegans CL4176. Our study suggested total flavonoids from sea buckthorn (Hippophae rhamnoides L.) had the potential as an antioxidative and neuroprotective agent to extend aging and treat neurodegenerative diseases.

A laser welding technology for the dissimilar materials 316L stainless steel (316L ss) and polylactic acid (PLA) was investigated to analyze the process parameters, which have a large influence on the joint quality. Orthogonal tests, single-factor tests, response surface method (RSM), and Box–Behnken design (BBD) were utilized to optimize the experimental design. A metallographic microscopy analysis was conducted to classify the joint morphology into two categories: effective and ineffective. The effective area ratio was established as an effective judgment method for the joint mechanical properties. Mathematical relations between the process parameters and the mechanical properties of the joints were investigated and the process parameters were optimized and validated. The test values were in excellent agreement with the actual values, thus demonstrating the reliability of the proposed model.

Alternating current field measurement (ACFM) is a technology for detecting magnetic flux leakage (MFL) using a magnetic sensor and is often used to detect welding defects. An alternating magnetic field was generated under the excitation of an alternating electric field. The magnetic field direction of an alternating magnetic field changes with time and the size and direction of the leakage magnetic field on the weldment also change periodically. In order to verify this rule, the distribution of the leakage magnetic field in different magnetisation directions was analysed through simulation and experiment. The simulation results show that when sinusoidal excitation is applied to the coil, the direction of magnetisation changes with time and the magnetic field density (B) gradually changes periodically on the weldment. This was verified through related experiments. When the surface of the weldment had welding defects, the dynamic magneto-optical image was captured in different magnetisation directions. Welding defects have different magneto-optical images in different frames, which can present more information for the same defect. In addition, in the experiment, the correlation between the grey-level co-occurrence matrix (GLCM) of magneto-optical images in different magnetisation directions and that of the leakage magnetic field in the corresponding direction was analysed. Simulations and experiments were performed on different types of welding defect. It was found that the trend of characteristics for the leakage magnetic fields was similar to that of the characteristics for the grey-level co-occurrence matrix of the magneto-optical images. The results show that the characteristics of the leakage magnetic field can reflect the texture features of the welding defect.

Additional file 1: Figure S1. Propensity score histograms by treatment status (untreated = Shanghai-native, treated = internal migrants).

In order to monitor the quality of laser welding in real time, a photoelectric sensor system is designed, which can collect the light radiation signals of the welding area in real time. The signals are converted into voltage signals by the photoelectric sensor and collected by the data acquisition card. Matlab software is used to analyze the power spectrum of the collected data. It is found that visible light and reflected light have similar power spectrum characteristics through experimental analysis, and the number of peaks and peak frequencies of the power spectrum have an obvious relationship with the quality of the weld. The results show that the detection system can effectively monitor welding defects in real time.

Organic-inorganic halide perovskites have been shown to be outstanding photovoltaic materials, achieving remarkably high power conversion efficiency (15%) of sunlight to electricity within the past 4 years. The controllable synthesis of organic-inorganic halide perovskites is fundamental to their applications in photovoltaic devices. Here we explore a novel strategy to prepare a typical halide peroskite CH3NH3PbI3 by transforming PbO-PbI2 hybrid materials. CH3NH3PbI3 thin films were deposited on glass substrates by reacting ultrasonic-assisted successive ionic layer adsorption and reaction (SILAR)-derived PbO-PbI2 hybrid films with CH3NH3I vapor at 110 °C. The microstructure and crystallinity of the films, together with the optical and electrical properties were characterized. Results show that CH3NH3PbI3 thin films possess perovskite crystal structure and uniform surface morphology with grain size up to 400 nm. In the visible band, CH3NH3PbI3 thin films showed low transmittance (below 10%), with a band gap of 1.58 eV. The surface resistivity of CH3NH3PbI3 thin films was as high as 1000 MΩ, indicating the dielectric nature of obtained CH3NH3PbI3 films, with a dielectric constant of er(100 Hz)=155 on low frequency. The current work opens an effective route toward high quality organic- inorganic halide perovskite films with good crystallinity and optical properties, which make them suitable for application in photovoltaic devices, and other optical and electrical applications.

During deep penetration laser welding, there exist plume (weak plasma) and spatters, which are the results of weld material ejection due to strong laser heating. The characteristics of plume and spatters are related to welding stability and quality. Characteristics of metallic plume and spatters were investigated during high-power disk laser bead-on-plate welding of Type 304 austenitic stainless steel plates at a continuous wave laser power of 10 kW. An ultraviolet and visible sensitive high-speed camera was used to capture the metallic plume and spatter images. Plume area, laser beam path through the plume, swing angle, distance between laser beam focus and plume image centroid, abscissa of plume centroid and spatter numbers are defined as eigenvalues, and the weld bead width was used as a characteristic parameter that reflected welding stability. Welding status was distinguished by SVM (support vector machine) after data normalization and characteristic analysis. Also, PCA (principal components analysis) feature extraction was used to reduce the dimensions of feature space, and PSO (particle swarm optimization) was used to optimize the parameters of SVM. Finally a classification model based on SVM was established to estimate the weld bead width and welding stability. Experimental results show that the established algorithm based on SVM could effectively distinguish the variation of weld bead width, thus providing an experimental example of monitoring high-power disk laser welding quality.

With the development of simulation technologies, simulation test has become an important means of weapon equipment demonstration, finalization and operational test and evaluation, but the simulation test system built for the performance evaluation cannot meet the requirements of system of systems (SoS) operational test and evaluation. This paper analyzes the requirements of the operational simulation test for the intelligent simulation test system and puts forward an intelligent simulation framework of the complex simulation test system and its main elements, which realizes the simulation of the operational activities with uncertain confrontation process and can support the demonstration, construction and evaluation of the weapon equipment system. The research results have been applied to the construction of a certain simulation system and provided support for the test and evaluation of equipment SoS tests.

A one-step deposition method was adopted to form the organic–inorganic mixed halide perovskite (CH3NH3PbI3−xClx) on compact ZnO in order to study the effect of annealing temperature on perovskite f...

During high power disk laser welding, the high-speed photography was used to measure the dynamic images of the laser-induced plume at different laser welding speeds. Various plume features (area, height and brightness) were extracted from the images by the color space clustering algorithm. Combined with observation on the surface and the cross sections of welding samples, the effect of welding speed on welding stability was analyzed. From the experimental results, it was found that these features of plume could reflect the welding state. Thus changes of the plume features corresponded to different welding speeds, which was helpful for monitoring the laser welding stability.

Highly crystalline, porous ZnO sheets were prepared from chemically-deposited zinc sulfate hydroxide hydrate (ZSH) sheets by sintering at 1000 °C. The formation mechanism of ZSH in Zn 2+ - hexamethyltetramine (HMT) precursor system, the transformation process of ZSH to ZnO, and the crystalline, microstructural and optical properties of the ZnO sheets were investigated. The porous ZnO sheets possessed a well-defined hexagonal shape with controllable size (10-50 μm) and thickness (200-500 nm), high crystallinity, and strong ultraviolet photoluminescence without detectable defect- related visible emission. Submicron-sized pores (100-500 nm) and polygonal or irregular ZnO particles resulting from the limited mass transport during high temperature sintering were observed in the ZnO sheets. Analysis of the formation mechanism indicated that the high affinity of SO 2

A new layered oxysulfide La5Cu6O4S7, composed of anti-PbO-like [Cu2S2] slabs alternating with PbO-like [La10O8S2] slabs and exhibiting high p-type conductivity, was fabricated by solid-state reaction method using La2S3 and characterized for the first time. The compound exhibited optical band gap of 2.0 eV, p-type electrical conductivity of 2.17 S cm−1 at room temperature, and metallic-like conducting behavior in the range of 150–450 K. La5Cu6O4S7 has presented another new and feasible way in achieving high conductivity, only partly structure-distortion rather than acceptor-doping, for applicable p-type semiconductor.

The observation of three events for the decay $\Sigma^+ \to p \mu^+ \mu^-$ with a dimuon invariant mass of $214.3\pm0.5$MeV by the HyperCP collaboration imply that a new particle X may be needed to explain the observed dimuon invariant mass distribution. We show that there are regions in the SUSY-FCNC parameter space where the $A^0_1$ in the NMSSM can be used to explain the HyperCP events without contradicting all the existing constraints from the measurements of the kaon decays, and the constraints from the $K^0-\bar{K}^0$ mixing are automatically satisfied once the constraints from kaon decays are satisfied., Comment: 18 pages, 7 figures

Ultrasonic Assisted SILAR method (UA-SILAR) was developed and highly oriented ZnO films were deposited on the glass substrate by this novel technique. The crystallinity and microstructure of as-deposited ZnO films were analyzed by means of XRD and SEM. Moreover, the underling deposition mechanism of ZnO films was discussed. Results show that obtained ZnO films exhibit an excellent crystallinity with the preferential orientation of (002) plane. The crystalline grain of films is about 40nm in size, which is supported by both the Sherrer equation and the SEM result. However, the ZnO film is composed of numerous clustered particulates in the size of 200 to 300nm, and each particulate is the compact aggregation of smaller ZnO crystalline grains. It is speculated that the excellent crystallinity of ZnO films may chiefly originate from the cavatition effect of the ultrasonic rinsing process.

A seam tracking method is presented based on the estimation of weld position during the gas tungsten arc welding process. Kalman filtering of the weld pool images from a visual sensor is applied to compute recursively the solution to the weld position equations which are established based on an estimation of the centroid position of the weld pool images. This centroid, the position of which corresponds with the weld position, is extracted as the measurement eigenvector. The evolution of the weld position data from the weld pool images can be described through an appropriate process model, so that the weld position can be detected by applying a Kalman filter. This allows adjustment of the welding torch position in real time, which may significantly reduce processing time and promote seam tracking accuracy. Simulations and actual welding experiments have demonstrated the effectiveness of the proposed algorithm in the presence of weld pool image noise and have demonstrated the robustness of weld posi...

We calculate the branching ratios and CP asymmetries of the $B \to \pi \rho$, $\pi\omega $ decays in the perturbative QCD factorization approach up to the next-to-leading-order contributions. We find that the next-to-leading-order contributions can interfere with the leading-order part constructively or destructively for different decay modes. Our numerical results have a much better agreement with current available data than previous leading-order calculations, e.g., the next-to-leading-order corrections enhance the $B^0\rightarrow \pi^0\rho^0$ branching ratios by a factor 2.5, which is helpful to narrow the gaps between theoretic predictions and experimental data. We also update the direct CP-violation parameters, the mixing-induced CP-violation parameters of these modes, which show a better agreement with experimental data than many of the other approaches.

We calculate contributions to ${B}_{s}\mathrm{\text{\ensuremath{-}}}{\overline{B}}_{s}$ mixing through tree-level sneutrino exchange in the framework of the minimal supersymmetric standard model with $R$-parity violation, including the next-to-leading-order QCD corrections. We compare our results with the updated bounds on the ${B}_{s}\mathrm{\text{\ensuremath{-}}}{\overline{B}}_{s}$ mass difference reported by CDF collaborations and present new constraints on the relevant combinations of parameters of the minimal supersymmetric standard model with $R$-parity violation. Our results show that upper bound on the relevant combination of couplings of ${B}_{s}\mathrm{\text{\ensuremath{-}}}{\overline{B}}_{s}$ mixing is of the order ${10}^{\ensuremath{-}9}$. We also calculate the ${B}_{d}^{0}\mathrm{\text{\ensuremath{-}}}{\overline{B}}_{d}^{0}$ and ${K}^{0}\mathrm{\text{\ensuremath{-}}}{\overline{K}}^{0}$ mass differences and show that the upper bounds on the relevant combinations of couplings are 2 and 4 orders of magnitude stronger than ones reported in the literatures, respectively. We also discuss the case of complex couplings and show that how the relevant combinations of couplings are constrained by the updated experiment data of ${B}_{s}\mathrm{\text{\ensuremath{-}}}{\overline{B}}_{s}$, ${B}_{d}\mathrm{\text{\ensuremath{-}}}{\overline{B}}_{d}$ mixing and time-dependent $CP$ asymmetry ${S}_{J/\ensuremath{\psi}{K}_{s}}$, and future possible observations of ${S}_{J/\ensuremath{\psi}\ensuremath{\phi}}$ at the Large Hadron Collider beauty experiment (LHCb), respectively.

In a laser butt joint welding process, it is required that the laser beam focus should be controlled to follow the weld joint path accurately. Small focus wandering off the weld joint may result in insufficient penetration or unacceptable welds. Recognition of joint position offset, which describes the deviation between the laser beam focus and the weld joint, is important for adjusting the laser beam focus and obtaining high quality welds. A new method based on the magneto-optical (MO) imaging is applied to measure the micro weld joint whose gap is less than 0.2 mm. The weldments are excited by an external magnetic field, and an MO sensor based on principle of Faraday magneto effect is used to capture the weld joint images. A sequence of MO images which are tested under different magnetic field intensities and different weld joint widths are acquired. By analyzing the MO image characteristics and extracting the weld joint features, the influence of magnetic field intensity and weld joint width on the MO images and detection of weld joint position is observed and summarized.

We calculate contributions to $B_s-\bar{B}_s$ mixing through tree-level sneutrino exchange in the framework of the minimal supersymmetric standard model with R-parity violation, including the next-to-leading-order QCD corrections. We compare our results with the updated bounds on the $B_s-\bar{B}_s$ mass difference reported by CDF collaborations, and present new constraints on the relevant combinations of parameters of the minimal supersymmetric standard model with R-parity violation. Our results show that upper bound on the relevant combination of couplings of $B_s-\bar{B}_s$ mixing is of the order $10^{-9}$. We also calculate the $B^0_d-\bar{B}^0_d$ and $K^0-\bar{K}^0$ mass differences, and show that the upper bounds on the relevant combinations of couplings are two and four orders of magnitude stronger than ones reported in the literatures, respectively. We also discuss the case of complex couplings and show that how the relevant combinations of couplings are constrained by the updated experiment data of $B_s-\bar{B}_s$, $B_d-\bar{B}_d$ mixing and time-dependent CP asymmetry $S_{J/\psi K_s}$, and future possible observations of $S_{J/\psi\phi}$ at LHCb, respectively., Comment: A version to be published in PRD

A fuzzy logic controller (FLC) used for the seam tracking of an arc welding robot is presented in this paper. The paper discusses the issues of the fuzzy logic which are pertinent to the design and implementation of an intelligent seam tracking controller. This controller is designed to operate in the uncertain environment of weld seam tracking. The characteristics of the proposed fuzzy controller combined with an integrator have provided for the salient feature of robot joint position control under uncertain disturbances. It enables an arc welding robot to track the weld seam accurately. The effectiveness of the proposed fuzzy algorithms is demonstrated by computer simulation. Compared with a conventional PID controller, the fuzzy controller yields conspicuously improved performance.

There exists plenty of welding quality information on a molten pool during high-power fiber laser welding. An approach for monitoring the high-power fiber laser welding status based on the principal component analysis (PCA) of a molten pool configuration is investigated. An infrared-sensitive high-speed camera was used to capture the molten pool images during laser butt-joint welding of Type 304 austenitic stainless steel plates with a high-power (10 kW) continuous wave fiber laser. In order to study the relationship between the molten pool configuration and the welding status, a new method based on PCA is proposed to analyze the welding stability by comparing the situation when the laser beam spot moves along, and when it deviates from the weld seam. Image processing techniques were applied to process the molten pool images and extract five characteristic parameters. Moreover, the PCA method was used to extract a composite indicator which is the linear combination of the five original characteristics to analyze the different status during welding. Experimental results showed that the extracted composite indicator had a close relationship with the actual welding results and it could be used to evaluate the status of the high-power fiber laser welding, providing a theoretical basis for the monitoring of laser welding quality.

Photon-pair direct or jet-associated productions are important for relevant standard model measurement, Higgs and new physics searches at the LHC. The loop-induced gluon-fusion process gg -> \gamma\gamma g, which although formally contributes only at the next-to-next-to-leading order to \gamma\gamma j productions, may get enhanced by the large gluon flux at the LHC. We have checked and confirmed previous results on gg -> \gamma\gamma, \gamma\gamma g at one loop, using now the traditional Feynman diagram based approach and taking into account the quark mass effects, and further updated them for the 7 and 14 TeV LHC with new inputs and settings. We provide the details and results of the calculations, which involves manipulation of rank-5 pentagon integrals. Our results show that the gluon-fusion process can contribute about 10% of the Born result, especially at small M_{\gamma\gamma} and PT_{\gamma\gamma}, and increase further the overall scale uncertainty. Top quark loop effects are examined in detail, which shows importance near or above the threshold M_{\gamma\gamma} \gsim 2m_t., Comment: 10 pages, 5 figures

Real-time monitoring and control of welding process is important for laser welding quality. Therefore, the variation rule of sensing characteristics of welding process and their relations to weld quality should be known. Spatter is one of the most important phenomena in high-power laser welding process. The characteristics of spatters are related to the quality and stability of welding and the utilization of the laser power. An approach to analyze the characteristics of spatters is investigated during high-power disk laser bead-on-plate welding of Type 304 austenitic stainless steel plates at a continuous wave laser power of 10 kW. An ultraviolet and visible sensitive high-speed video camera is used to capture the dynamic images of the laser welding spatters. The number, area, and ejecting distance of spatters and the centroid height of spatter images are calculated as the characteristic parameters of spatters by using the image processing technology. The weld bead width is considered as a parameter reflecting the quality and stability of welding process. The linear and the higher order polynomial curve fitting for the data of the characteristic parameters are used to study the variation rule of the characteristic parameters of spatters. In comparison of the fluctuation of the weld bead width, the correlation between the spatter characteristics and the quality and stability of welding is studied. The experimental results of actual laser welding show that the quality and stability of a high-power disk laser welding of Type 304 austenitic stainless steel plates could be monitored and estimated by analyzing the characteristic parameters of spatters, which is the foundation for monitoring and control of welding quality in real time.

Seam tracking is a significant precondition to obtain good welding quality. During the laser welding, the laser beam focus must be controlled to follow the welding seam accurately. A novel approach to detecting the offset between the laser beam focus and the welding seam based on infrared image processing is investigated during high-power fiber laser butt-joint welding of type 304 austenitic stainless steel plates at a continuous wave fiber laser power of 10 kW. The joint gap width is less than 0.1 mm. An infrared sensitive high speed camera arranged in off-axis direction of laser beam is used to capture the dynamic thermal images of a molten pool. The characteristics of thermal distribution and infrared radiation of the molten pool, when the laser beam focus is deviated from the welding seam center, are analyzed. Two parameters called the keyhole morphological parameter and the heat accumulation effect parameter are defined as the characteristic values of seam tracking offset to determine the offset between the laser beam focus and the desired welding seam. Also, the image processing technique is used to analyze the infrared images of the molten pool, which indicates the presence of mathematic correlation between the defined two parameters and the seam tracking offset. The welding experiments confirm that the offset between the laser beam focus and the welding seam can be estimated by the keyhole morphological parameter and the heat accumulation effect parameter effectively.

This paper establishes two artificial neural network models by using a multi layer perceptron algorithm and radial based function algorithm in order to predict the plasma density in a plasma system. In this model, the input layer is composed of five neurons: the radial position, the axial position, the gas pressure, the microwave power and the magnet coil current. The output layer is the target output neuron: the plasma density. The accuracy of prediction is tested with the experimental data obtained by the Langmuir probe. The effectiveness of two artificial neural network models are demonstrated, the results show good agreements with corresponding experimental data. The ability of the artificial neural network model to predict the plasma density accurately in an electron cyclotron resonance-plasma enhanced chemical vapour deposition system can be concluded, and the radial based function is more suitable than the multi layer perceptron in this work.