Chromatographic determination,decline dynamic and risk assessment of sulfoxaflor in Asian pear and oriental melon

The dissipation pattern of sulfoxaflor in Asian pear cultivated in an open field conditions and in oriental melon grown under plastic house conditions was each studied in two different locations. Residues in field‐treated samples were determined using liquid chromatography coupled with an ultraviolet detector and confirmed by liquid chromatography–tandem mass spectrometry. A calibration curve for sulfoxaflor was linear over the concentration range 0.1–5.0 mg/L, with a coefficient of determination of 0.9999. The limits of detection and quantification (LOQ) were 0.007 and 0.02 mg/kg, respectively. Recoveries at three fortification levels (LOQ, 10 × LOQ and maximum residue limit) ranged from 70.5 to 86.2%, with a relative standard deviation ≤5.8%. The dissipation half‐lives were 10.8 and 7.9 days in pear and 5.4 and 5.9 days in oriental melon, at sites 1 and 2, respectively. Based on a pre‐harvest residue limit curve, it was predicted that, if the residues at 10 days before harvest in Asian pear are <0.54/0.61 mg/kg and those in oriental melon are <1.43/1.26 mg/kg, then the residue level will be below the maximum residue limit at harvest. Risk assessment at zero days showed a percentage acceptable daily intake of 10.80% in Asian pear and 1.77 and 1.55% in oriental melon, for sites 1 and 2, respectively. These values indicate that the fruits are safe for consumption.     

Dynamic residual pattern of azoxystrobin in Swiss chard with contribution to safety evaluation

This study aimed at quantifying the residual amount of azoxystrobin in Swiss chard samples grown under greenhouse conditions at two different locations (Gwangju and Naju, Republic of Korea). Samples were extracted with acetonitrile, separated by salting out, and subjected to purification by using solid‐phase extraction. The analyte was identified using liquid chromatography–ultraviolet detection. The linearity of the calibration range was excellent with coefficient of determination 1.00. Recovery at three different spiking levels (0.1, 0.5, and 4 mg/kg) ranged between 82.89 and 109.46% with relative standard deviation <3. The limit of quantification, 0.01 mg/kg, was considerably much lower than the maximum residue limit (50 mg/kg) set by the Korean Ministry of Food and Drug Safety. The developed methodology was successfully used for field‐treated leaves, which were collected randomly at 0–14 days following azoxystrobin application. The rate of disappearance in/on Swiss chard was ascribed to first‐order kinetics with a half‐life of 8 and 5 days, in leaves grown in Gwangju and Naju greenhouses, respectively. Risk assessments revealed that the acceptable daily intake percentage is substantially below the risk level of consumption at day 0 (in both areas), thus encouraging its safe consumption.     

Duality in parameter space and approximation of measures for mixing repellers

For one-dimensional expanding mapsT with an invariant measure we consider, in a parameter space, the envelope _n of the real lines associated to any couple of points of the orbit, connected byn iterations ofT. If the map hass inverses and is piecewise linear, then the sets _n are just the union ofs ⁿ points and converge to the invariant Cantor set ofT. A correspondence between all the sets and their measures is established and allows one to associate the atomic measure on ₁ to the completly continuous measure on the Cantor set. If the map is nonlinear, hyperbolic, and hass inverses, the sets _n are homeomorphic to the Cantor set; they converge to the Cantor set ofT and their measures converge to the measure of the Cantor set whenn. The correspondence between the sets _n allows one to define converging approximation schemes for the map an its measure: one replaces each of thes ⁿ disjoint sets with a point in a convenient neighborhood and a probability equal to its measure and transforms it back to the original set ₁. All the approximations with linear Cantor systems previously proposed are recovered, the converging proprties being straightforward in the present scheme. Moreover, extensions to higher dimensionality and to nondisconnected repellers arte possible and are briefly examined.     

Encryption and decryption using a sandwich phase diffuser made by using two speckle patterns and placed in the Fourier plane: Simulation results

In the present paper, we describe the encryption and decryption of two-dimensional images. The encryption is done by employing a sandwich phase diffuser made by using two elongated speckle patterns, and placed in the Fourier plane of a double random phase encoding system. After encryption, the two constituent phase diffusers of such a sandwich diffuser are separated. During decryption, if the conjugate of either of the two elongated phase speckle patterns is used, the image cannot be retrieved. Correct decryption is also not possible if a sandwich diffuser with any of the phase speckle patterns is shifted in position with respect to the other. For decryption, the encrypted image is Fourier transformed and multiplied by the conjugate of the sandwich diffuser, and then the product is further Fourier transformed. It is possible to generate the image only if both the elongated phase speckle patterns are matched point-to-point and then the proper conjugate is made. The use of elongated speckle patterns in constituting a sandwich phase diffuser makes the system less complicated as compared to the use of a sandwich diffuser made with normal speckle patterns, enabling an easy alignment of the random phase diffuser at the time of rejoining the constituent diffusers for making the right key. The ease of alignment is due to the reduction of the requirement of 360° scanning at the time of rejoining these diffusers with little reduction in the security of the system. Simulation results are presented in support of the proposed idea. For optical implementation, the decrypted image may be obtained by generating a phase conjugate wave by the phase conjugation technique, and passing through the same sandwich phase diffuser. To evaluate the reliability of the technique, mean square error (MSE) between the decrypted and original image has been calculated.     

Analysis on Patterns of Globally Coupled Phase Oscillators with Attractive and Repulsive Interactions

The Hong-Strogatz (HS) model of globally coupled phase oscillators with attractive and repulsive interactions reflects the fact that each individual (oscillator) has its own attitude (attractive or repulsive) to the same environment (mean field). Previous studies on HS model focused mainly on the stable states on Ott-Antonsen (OA) manifold. In this paper, the eigenvalues of the Jacobi matrix of each fixed point in HS model are explicitly derived, with the aim to understand the local dynamics around each fixed point. Phase transitions are described according to relative population and coupling strength. Besides, the dynamics off OA manifold is studied.     

Pattern recognition and data mining software based on artificial neural networks applied to proton transfer in aqueous environments

In computational physics proton transfer phenomena could be viewed as pattern classification problems based on a set of input features allowing classification of the proton motion into two categories： transfer ＇occurred＇ and transfer ＇not occurred＇. The goal of this paper is to evaluate the use of artificial neural networks in the classification of proton transfer events, based on the feed-forward back propagation neural network, used as a classifier to distinguish between the two transfer cases. In this paper, we use a new developed data mining and pattern recognition tool for automating, controlling, and drawing charts of the output data of an Empirical Valence Bond existing code. The study analyzes the need for pattern recognition in aqueous proton transfer processes and how the learning approach in error back propagation （multilayer perceptron algorithms） could be satisfactorily employed in the present case. We present a tool for pattern recognition and validate the code including a real physical case study. The results of applying the artificial neural networks methodology to crowd patterns based upon selected physical properties （e.g., temperature, density） show the abilities of the network to learn proton transfer patterns corresponding to properties of the aqueous environments, which is in turn proved to be fully compatible with previous proton transfer studies.     

Maximum norms of random sums and transient pattern formation

Many interesting and complicated patterns in the applied sciences are formed through transient pattern formation processes. In this paper we concentrate on the phenomenon of spinodal decomposition in metal alloys as described by the Cahn-Hilliard equation. This model depends on a small parameter, and one is generally interested in establishing sharp lower bounds on the amplitudes of the patterns as the parameter approaches zero. Recent results on spinodal decomposition have produced such lower bounds. Unfortunately, for higher-dimensional base domains these bounds are orders of magnitude smaller than what one would expect from simulations and experiments. The bounds exhibit a dependence on the dimension of the domain, which from a theoretical point of view seemed unavoidable, but which could not be observed in practice.

In this paper we resolve this apparent paradox. By employing probabilistic methods, we can improve the lower bounds for certain domains and remove the dimension dependence. We thereby obtain optimal results which close the gap between analytical methods and numerical observations, and provide more insight into the nature of the decomposition process. We also indicate how our results can be adapted to other situations.

     

ρ混合、φ混合、ψ混合线性模型M估计的强相合性

研究了 ρ混合、φ混合、ψ混合样本线性模型中回归参数M估计的强相合性 ,在条件不变的情况下 ,获得与独立情形一样的M估计是强相合的充分条件 ,推广了文 [1 ]定理 2 .     

Using multi-exposure of color fringes to measure the beating motion of a moth

A multi-exposure of color fringes method has been developed to improve the capture speed of a conventional color CCD camera. In the method, four groups of projected fringe patterns encoded with different colors and different directions are stored in one CCD frame. Therefore the capture frequency of the conventional CCD can be improved to 200 Hz. It is available to measure the insect wings with low beating frequency, such as dragonfly, moth, or butterfly, whose beating frequency is about 30–40 Hz. We have used the method to measure the beating motion of a moth successfully.     

时间序列散斑干涉技术研究及应用

当用相干激光照射在一个连续位移或变形的漫射物体表面时,在与参考光形成干涉的接收面上即产生一随时间变化的散斑干涉场通过对这一干涉场的时间域进行分析,可实现时变位移场的定量检测本文介绍了基本时间序列散斑干涉场的扫描相位方法和时间序列相位法的相位函数解调原理,探讨了它们的计量特性,并将其用于火箭固体燃料性能的检测.