Krein Space-Based H

This paper investigates the finite-time H∞ fault estimation problem for linear time-delay systems, where the delay appears in both state and measurement equations. Firstly, the design of finite horizon H∞ fault estimation is converted into a minimum problem of certain quadratic form. Then we introduce a stochastic system in Krein space, and a sufficient and necessary condition for the minimum is derived by applying innovation analysis approach and projection theory. Finally, a solution to the H∞ fault estimation is obtained by recursively computing a partial difference Riccati equation, which has the same dimension as the original system. Compared with the conventional augmented approach, the solving of a high dimension Riccati equation is avoided

Global Practical Tracking by Output Feedback for Nonlinear Systems with Unknown Growth Rate and Time Delay

This paper is the further investigation of work of Yan and Liu, 2011, and considers the global practical tracking problem by output feedback for a class of uncertain nonlinear systems with not only unmeasured states dependent growth but also time-varying time delay. Compared with the closely related works, the remarkableness of the paper is that the time-varying time delay and unmeasurable states are permitted in the system nonlinear growth. Motivated by the related tracking results and flexibly using the ideas and techniques of universal control and dead zone, an adaptive output-feedback tracking controller is explicitly designed with the help of a new Lyapunov-Krasovskii functional, to make the tracking error prescribed arbitrarily small after a finite time while keeping all the closed-loop signals bounded. A numerical example demonstrates the effectiveness of the results

Calculated phase diagrams, iron tolerance limits, and corrosion of Mg-Al alloys

The factors determining corrosion are reviewed in this paper, with an emphasis on iron tolerance limit and the production of high-purity castings. To understand the iron impurity tolerance limit, magnesium phase diagrams were calculated using the Pandat software package. Calculated phase diagrams can explain the iron tolerance limit and the production of high-purity castings by means of control of melt conditions; this is significant for the production of quality castings from recycled magnesium. Based on the new insight, the influence of the microstructure on corrosion of magnesium alloys is reviewed

Study on the culture of Escherichia coli with different hydrolysis depth of globin

Objective: To explore the effect of culture medium made of peptide fragments of different sizes of globin hydrolyzed by protease on the culture of Escherichia coli. Method: with fresh pig blood as raw material, hydrolyze pig blood protein under fixed conditions, and screen out the enzyme with the highest degree of hydrolysis. Then conduct orthogonal test on the enzyme to determine the best hydrolysis conditions; the beads were obtained under the best hydrolysis conditions. The Escherichia coli was cultured on different peptone culture bases that were prepared by hydrolysate going through different pore size ultrafiltration membrane samples. The culture of Escherichia coli at different hydrolysis depths is determined by detecting the total amount with Escherichia coli detection method. Results: Trypsin has the best hydrolysis effect. The best hydrolysis conditions are as follows: enzyme dosage of 0.2%, hydrolysis time of 12h, temperature of 50°C, initial pH of 7.5 and mass fraction of substrate protein of 8%. Through growth curves of Escherichia coli, it is known that the smaller the pore size of the ultrafiltration membrane, the smaller the molecular weight of the peptide fragment, and the greater the density of the Escherichia coli bacterial solution. Conclusion: Through analyzing the production curves of Escherichia coli in different culture medium, it is concluded that the smaller the molecular weight of the protein peptides, the higher the density of Escherichia coli solution in the LB liquid medium prepared by it, and the better the Escherichia coli culture effect

Research on the synthesis of chitosan@MIL-100(Fe)

Objective: Studying new carrier materials to solve the problems of bioavailability and side effects of drugs in the body and choose the suitable carrier to coat the drug. This carrier not only improves the release and absorption of drug molecules in the body, but also significantly improves the bioavailability and reduces the toxic side effects of high concentrated drugs. Therefore, this paper focuses on the research of the synthesis of a new carrier material. Methods:Using ferric nitrate as iron source, first add ferric nitrate, 1,3,5-benzene tricarbonic acid, chitosan solution and deionized water pro rata, then synthesize the product using mechanical stirring, and purify and dry the product. Results:The maximum yield of chitosan is obtained when the concentration of chitosan is 1% using mechanical stirring method, and the yield is 0.6330 g. Conclusion:The results show that the thinner the concentration of chitosan solution is, the better synthesizes the chitosan@MIL-100(Fe) and the higher the yield is. And it reaches the best result when the concentration is 1%

Survey of duality between linear quadratic regulation and linear estimation problems for discrete-time systems

Abstract The linear estimation (or optimal control) problem in the emerging area of time-delay systems, multiplicative noise systems, and Markov jump linear systems has been taken into consideration by the control engineers. The purpose of this survey is to provide a review of duality between linear estimation and optimal control in the above-mentioned area. The mentioned subjects are studied to indicate the essential connection between control and estimation problems and to investigate the major cause that the classical duality still holds (not holds) for the broader systems, such as time-delay systems, multiplicative noise systems, Markov jump linear systems, and the like

Analysis on the Man-Machine-Environment Collaborative Teaching Method for Mining Engineering Major

Man, teaching equipment (machine), and teaching environment in the higher education system constitute the man–machine–environment system in the teaching system. In this study, modern higher pedagogy is combined with man–machine–environment system engineering. The teaching system is analyzed in the point of view of mining engineering profession and a new type of “man-machine-environment collaborative teaching method” is proposed. Also, we conducted a comprehensive discussion about the academic problems in various aspects of composition, theoretical basis, and functional allocation by combining teaching reform features of the mining engineering profession. The practice of man–machine–environment collaborative teaching method strengthens students’ learning of perceptual knowledge, alleviates difficulty of site visit and practice, and enables conducting an indoor interactive dynamic simulation experiment. Moreover, it cultivated the students’ operational ability, spatial thinking, and global concept of industrial mining sites. Furthermore, it improved the autonomous learning ability of undergraduates, which was of great significance to cultivating innovative talents. Lastly, it transformed the teaching method from “teaching” to initiative “exploration” and “discovery” for students

Analysis on the Man-Machine-Environment Collaborative Teaching Method for Mining Engineering Major

Man, teaching equipment (machine), and teaching environment in the higher education system constitute the man–machine–environment system in the teaching system. In this study, modern higher pedagogy is combined with man–machine–environment system engineering. The teaching system is analyzed in the point of view of mining engineering profession and a new type of “man-machine-environment collaborative teaching method” is proposed. Also, we conducted a comprehensive discussion about the academic problems in various aspects of composition, theoretical basis, and functional allocation by combining teaching reform features of the mining engineering profession. The practice of man–machine–environment collaborative teaching method strengthens students’ learning of perceptual knowledge, alleviates difficulty of site visit and practice, and enables conducting an indoor interactive dynamic simulation experiment. Moreover, it cultivated the students’ operational ability, spatial thinking, and global concept of industrial mining sites. Furthermore, it improved the autonomous learning ability of undergraduates, which was of great significance to cultivating innovative talents. Lastly, it transformed the teaching method from “teaching” to initiative “exploration” and “discovery” for students

Study on Extraction Technology of Pitaya Polysaccharide

Using pitaya as raw material, this paper used ethanol subsiding method to study the extraction technology of pitaya polysaccharide by single factor test and orthogonal test. Through orthogonal test, we have found the optimum extraction conditions of pitaya polysaccharide as follows: extraction temperature 60℃, solid-liquid ratio 1:30, extraction time 3h. Under the optimal extraction conditions, the yield of pitaya polysaccharide was 1.13%