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991.
Li Qun Ouyang Hai Long Wu Ya Juan Liu Jian Yue Wang Yong Jie Yu Hong Yan Zou Ru Qin Yu 《中国化学快报》2010,21(10):1223-1226
<正>A method using HPLC-DAD coupled with second-order calibration was developed to simultaneously determine metronidazole and tinidazole in plasma samples in this paper.The second-order calibration method based on APTLD(alternating penalty trilinear decomposition) algorithm was proposed to analyze the three-way HPLC-DAD data from both standard and prediction samples, which makes it possible that calibration can be performed even in the presence of unknown interferences with a simple and green chromatographic condition and short analysis time.The results showed that good recoveries were obtained although the chromatographic and spectral profiles of the analytes of interest as well as background were partially overlapped with each other in plasma samples. 相似文献
992.
Qun?Liu Daqing?JiangEmail author Tasawar?Hayat Ahmed?Alsaedi 《Journal of Nonlinear Science》2018,28(3):1151-1187
In this paper, we develop and study a stochastic predator–prey model with stage structure for predator and Holling type II functional response. First of all, by constructing a suitable stochastic Lyapunov function, we establish sufficient conditions for the existence and uniqueness of an ergodic stationary distribution of the positive solutions to the model. Then, we obtain sufficient conditions for extinction of the predator populations in two cases, that is, the first case is that the prey population survival and the predator populations extinction; the second case is that all the prey and predator populations extinction. The existence of a stationary distribution implies stochastic weak stability. Numerical simulations are carried out to demonstrate the analytical results. 相似文献
993.
In this paper nonstandard finite difference (NSFD) schemes of two metapopulation models are constructed. The stability properties of the discrete models are investigated by the use of the Lyapunov stability theorem. As a result of this we have proved that the NSFD schemes preserve essential properties of the metapopulation models (positivity, boundedness and monotone convergence of the solutions, equilibria and their stability properties). Especially, the basic reproduction number of the continuous models is also preserved. Numerical examples confirm the obtained theoretical results of the properties of the constructed difference schemes. The method of Lyapunov functions proves to be much simpler than the standard method for studying stability of the discrete metapopulation model in our very recent paper. 相似文献
994.
Chunlei Fan Qi Zhang Haoran Sun Bingbing Song Qun Ding 《Journal of Applied Analysis & Computation》2016,6(4):1126-1134
Nowadays, embedded network products are widely used in various technological fields. However, when such products are used, the transmission of network data could not be guaranteed with high security. To address the issue, this paper designed a network encryption machine based on S3C6410 processor and DM9000 Ethernet controller. The hardware circuit of this encryption machine is designed and developed with conciseness and stability. In software design, an improved algorithm of chaotic encryption based on Henon mapping is proposed. The algorithm overcomes the shortcoming in combining Logistic and Tent chaotic sequences. Moreover, the paper demonstrates some comparative experiments about autocorrelation and randomness. The results indicate that the new algorithm based on Henon chaotic sequences has a good performance in safety and is able to meet the requirements of confidential communications. 相似文献
995.
996.
997.
Xiaohui Yu Xiaogang Zhao Changwei Liu Zewei Bai Daming Wang Guodong Dang Hongwei Zhou Chunhai Chen 《Journal of polymer science. Part A, Polymer chemistry》2010,48(13):2878-2884
A series of polyimides containing ether and ketone moieties were synthesized from 1,3‐bis(4‐fluorobenzoyl) benzene and several commercially available dianhydrides via a conventional two‐step polymerization. The inherent viscosities of Polyamide acids ranged from 0.46 to 0.73 dL/g. Thermal properties, mechanical properties, and thermalplasticity of the obtained polimide films were investigated by focusing on the chemical structures of their repeat units. These films were amorphous, flexible, and transparent. All films displayed low Tgs (184–225 °C) but also excellent thermal stability, the 5% weight loss temperature was up to 542 °C under nitrogen. The films showed outstanding mechanical properties with the modulus up to 3.0 GPa and the elongation at break in the range of 8–160%. The uniaxial stretching of PI‐a at high temperature was studied owing to its excellent flexibility. The PI‐a had an elongation at break up to 1600% at 245 °C and the uniaxially stretched film exhibited a much higher modulus (3.9 GPa) and strength (240 MPa) than undrawn film. The results indicated that PI‐a can potentially be used to prepare materials such as fiber, ultra‐thin film or ultra‐high modulus film. All the obtained films also demonstrated excellent thermoplasticity (drop of E′ at Tg > 103) which made the polyimides more suitable for melt processing. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2878–2884, 2010 相似文献
998.
In this paper, we introduce complex pseudo splines that are derived from pseudo splines of type I. First, we show that the
shifts of every complex pseudo spline are linearly independent. Therefore we can construct a biorthogonal wavelet system.
Next, we investigate the Riesz basis property of the corresponding wavelet system generated by complex pseudo splines. The
regularity of the complex pseudo splines will be analyzed. Furthermore, by using complex pseudo splines, we will construct
symmetric or antisymmetric complex tight framelets with desired approximation order. 相似文献
999.
Prussian blue analogue nanoparticles doped with Ce(III) (CeHCF) have been synthesized using chitosan (CS) and poly(diallyldimethylammonium chloride) (PDDA) as protective matrix and were cast onto a glassy carbon electrode surface directly. Transmission electron microscopy, UV‐Vis absorption spectroscopy and resonance Rayleigh scattering technique were employed to characterize the PB analogue nanoparticles protected with CS and PDDA. Compared with the bare glassy carbon electrode, the modified electrode exhibited excellent performances for determining H2O2. This work demonstrates the feasibility of the CS‐PDDA‐CeHCF nanoparticles modified glassy carbon electrode for practical sensing applications. 相似文献
1000.
In this paper we present a filter-trust-region algorithm for solving LC1 unconstrained optimization problems which uses the second Dini upper directional derivative. We establish the global convergence of the algorithm under reasonable assumptions. 相似文献