Stochastic Bounded Consensus Tracking of Second-Order Multi-Agent Systems with Measurement Noises based on Sampled-Data with Small Sampling Delay

Zhihai Wu,Li Peng,Linbo Xie,Jiwei Wen 제어·로봇·시스템학회 2014 International Journal of Control, Automation, and Vol.12 No.1

This paper is devoted to the stochastic bounded consensus tracking problems of second-order multi-agent systems, where the control input of each agent can only use the information measured at the sampling instants from its neighbors or the virtual leader with a time-varying reference state, the measurements are corrupted by random noises, and the signal sampling process induces the small sampling delay. The augmented matrix method, the probability limit theory and some other techniques are employed to derive the necessary and sufficient conditions guaranteeing the mean square bounded consensus tracking. We show that the convergence of the proposed protocol simultaneously depends on the constant feedback gains, the network topology, the sampled period and the sampling delay, and that the static consensus tracking error depends on not only the above mentioned factors, but also the noise intensity and the upper bound of the velocity and the acceleration of the virtual leader. The obtained results cover no sampling delay as its one special case. Simulations are provided to demonstrate the effectiveness of the theoretical results.

Effects of Continuous Straw Returning on Soil Functional Microorganisms and Microbial Communities

Guan Yunpeng,Wu Meikang,Che Songhao,Yuan Shuai,Yang Xue,Li Siyuan,Tian Ping,Wu Lei,Yang Meiying,Wu Zhihai 한국미생물학회 2023 The journal of microbiology Vol.61 No.1

This study examined the changes in soil enzymatic activity, microbial carbon source metabolic diversity, and straw decomposition rates in paddy fields treated with 1, 2, or 3 years of straw returning (SR1–SR3). The soil’s ability to decompose straw and cellulolytic bacteria increased with the number of treatment years (1: 31.9% vs. 2: 43.9% vs. 3: 51.9%, P < 0.05). The numbers of Azotobacter, Nitrobacteria, cellulolytic bacteria, and inorganic phosphate bacteria increased progressively with the numbers of straw returning years. Cellulolytic bacteria and inorganic phosphate bacteria were significantly positively correlated with the decomposition rate (r = 0.783 and r = 0.375, P < 0.05). Based on 16S sequencing results, straw returning improved the microbial diversity of paddy soils by increasing unclassified bacteria and keeping dominant soil microorganism populations unchanged. The relative importance of individual microbial taxa was compared using random forest models. Proteobacteria, ammoniating bacteria, and potassium dissolving bacteria contributed to peroxidase activity. The significant contributors to phosphate monoesterase were Acidobacteriota, Desulfobacterota, ammoniating bacteria, cellulolytic bacteria, and potassium-dissolving bacteria. Proteobacteria, ammoniating bacteria, cellulolytic bacteria, and potassium-dissolving bacteria contributed to urease activity. Desulfobacterota, ammoniating bacteria, cellulolytic bacteria, and potassium-dissolving bacteria contributed to the neutral invertase activity. In conclusion, soil microbial community structure and function were affected within 2 years of straw returning, which was driven by the combined effects of soil organic carbon, available nitrogen, available potassium, and pH. With elapsing straw returning years, soil properties interacted with soil microbial communities, and a healthier soil micro-ecological environment would form.

The differentiation of rat-induced pluripotent stem cells into alveolar type II epithelial cells with a three-step induction protocol

Bei Wu,Chen Wang,Feilong Hei,Cun Long,Mengmeng Chen,Shengnan Yang,Jie Yu,Zhihai Ju 한국통합생물학회 2015 Animal cells and systems Vol.19 No.1

Induced pluripotent stem (iPS) cells derive from autologous somatic cells, the application prospect of iPS cells forregenerative medicine and tissue engineering is better than embryonic stem cells (ESCs) to some extent. Alveolar type II(AT II) epithelial cells play key role in the injured lung tissue regeneration and function recovery. The differentiation of iPScells into AT II cells could provide available source for injured lung treatment. In this study, rat iPS (riPS) cells wereresuscitated and proliferated for 14 days before differentiation. A modified three-step induction protocol similar to thereported ESCs inducing procedure was used in this study for the differentiation groups. Routine cell culture was done to theriPS cell control group (riPS-con). At stage 3, cells of day 7 (Diff. 7) and day 14 (Diff. 14) were collected for the real-timepolymerase chain reaction tests for gene expressions of Oct4, Nanog, SPA, SPB, SPC, SPD, and CC10. Immunofluorescencestaining of SPC and SSEA-1 was conducted. At the end of the differentiation, cell morphology becameoutstretched and epithelium-like. Cells of the Diff. 14 group positively expressed SPC and negatively expressed SSEA-1,which is contrary to the riPS-con group. In the Diff. 7 and the Diff. 14 groups, the expression of Oct4, Nanog, and SPBdecreased (P < 0.05), whereas the expression of SPA, SPC, SPD (P < 0.05), and CC10 (P > 0.05) increased. This studyindicated that riPS cells can successfully differentiate into AT II epithelial cells with the three-step induction protocol andmay be further applied to implanting in decellularized rat lung scaffolds and building a bio-artificial lung.

Moisture-Induced Reversible Softening of Polyacrylates-Stiffened Cotton Fabrics

Yifang Mi,Die Wu,Yongxiang Li,Xiaoxia Cheng,Xiaobo Yang,Shuxian Lan,Zhihai Cao 한국섬유공학회 2022 Fibers and polymers Vol.23 No.5

The stiffening finishing of cotton fabrics has been widely used in textile industry. However, the notorious softeningof stiffened fabrics attenuated the stiffening style during storage. To reveal crucial factors responsible for the softeningphenomenon and elucidate the mechanism, cotton twill woven fabrics finished with polyacrylates (PAcr) stiffening agentswere systematically analyzed. The sensitive index to stiffening effect, i.e. stiffness value, was found which can fully assessthe handle changes of stiffened fabrics. The stiffness value of stiffened cotton fabrics decreased rapidly in the initial stage ofstorage, and the declining extent was related to the hygroscopic behavior of stiffened fabrics. Based on the hygroscopickinetic data, hygroscopic-drying cyclic experiments, and morphology characterization, it was found that interfaces betweencotton fibers and stiffening agent film were maintained during the whole hygroscopic process, and the reason for handlechanges of stiffened cotton fabrics was ascribed to the reversible moisture-induced plasticization effect on PAcr stiffeningagent film and cotton fibers. Furthermore, the underlying softening mechanism was further proposed in this work. Collectively, the present results are crucial for anti-softening in stiffening finishing of hydrophilic fabrics and an importantpart for the research on the mechanism of softening of stiffened fabrics.

One-pot synthesis of double vacancy tazetta Bi5O7I for photocatalytic removal of mercury from flue gas

Weiqun Chu,Hailong Liu,Qilin Zhang,Fangqin Li,Cheng Peng,Zhihai Cheng,Jiang Wu,Sorachon Yoriya,Ping He,Hai Zhang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-

Regulation of carrier capture and transport is critical for the enhancement of photocatalytic activity. Inthis work, a Bi5O7I photocatalyst containing double vacant tazetta-like structure was synthesized byone-pot calcination. X-ray photoelectron spectroscopy (XPS) and electron spin resonance spectroscopy(ESR) analysis showed that the vacancy structure improved the activation performance of adsorbed oxygen,thereby promoting the participation of superoxide radicals in the photocatalytic reaction. The resultsof electron paramagnetic resonance (EPR), electrochemical impedance spectroscopy (EIS) and timeresolvedphotoluminescence spectroscopy (TRPL) revealed that the defect state induced by double vacanciescould adjust the electron transport pathway, and the fluorescence lifetime could reach 3.043 ns,which greatly improved the photocatalytic reactivity. We further tested the photocatalytic activity ofheavy metal mercury removal experiment, and the optimal photocatalytic mercury removal efficiencyincreased to 83%. Finally, combining the results of DFT calculation and photocatalytic mercury removalexperiments, we proposed the photocatalytic reaction mechanism of Bi5O7I regulated by double vacancies. Our work provides a more convenient method for the design of defect engineering photocatalystsand provides effective theoretical support for photocatalytic removal of heavy metal mercury in flue gas.