47 research outputs found
Optical limiting using Laguerre-Gaussian beams
We demonstrate optical limiting using the self-lensing effect of a
higher-order Laguerre-Gaussian beam in a thin dye-doped polymer sample, which
we find is consistent with our model using Gaussian decomposition. The peak
phase shift in the sample required for limiting is smaller than for a
fundamental Gaussian beam with the added flexibility that the nonlinear medium
can be placed either in front of or behind the beam focus.Comment: 3 pages, 4 figure
Comparative Genomic Analysis and Rapid Molecular Detection of Xanthomonas euvesicatoria Using Unique ATP-Dependent DNA Helicase recQ, hrpB1, and hrpB2 Genes Isolated from Physalis pubescens in China
Ground cherry (Physalis pubescens) is the most prominent species in the Solanaceae family due to its nutritional content, and prospective health advantages. It is grown all over the world, but notably in northern China. In 2019 firstly bacterial leaf spot (BLS) disease was identified on P. pubescens in China that caused by both BLS pathogens Xanthomonas euvesicatoria pv. euvesicatoria resulted in substantial monetary losses. Here, we compared whole genome sequences of X. euvesicatoria to other Xanthomonas species that caused BLS diseases for high similarities and dissimilarities in genomic sequences through average nucleotide identity (ANI) and BLAST comparison. Molecular techniques and phylogenetic trees were adopted to detect X. euvesicatoria on P. pubescens using recQ, hrpB1, and hrpB2 genes for efficient and precise identification. For rapid molecular detection of X. euvesicatoria, loop-mediated isothermal amplification, polymerase chain reaction (PCR), and real-time PCR techniques were used. Whole genome comparison results showed that the genome of X. euvesicatoria was more closely relative to X. perforans than X. vesicatoria, and X. gardneri with 98%, 84%, and 86% ANI, respectively. All infected leaves of P. pubescens found positive amplification, and negative controls did not show amplification. The findings of evolutionary history revealed that isolated strains XeC10RQ, XeH9RQ, XeA10RQ, and XeB10RQ that originated from China were closely relative and highly homologous to the X. euvesicatoria. This research provides information to researchers on genomic variation in BLS pathogens, and further molecular evolution and identification of X. euvesicatoria using the unique target recQ gene through advance molecular approaches
Finite element implementation of a multi-scale dynamic piezomagnetic continuum model
A gradient-enriched dynamic piezomagnetic model is presented. The gradient enrichment introduces a number of microstructural terms in the model that allow the description of dispersive wave propagation. A novel derivation based on homogenisation principles is shown to lead to a multi-scale formulation in which the micro-scale displacements and magnetic potential are included alongside the macro-scale displacements and magnetic potential. The multi-scale formulation of the model has the significant advantage that all higher-order terms are rewritten as second-order spatial derivatives. As a consequence, a standard C^0-continuous finite element discretisation can be used. Details of the finite element implementation are given. A series of one and two-dimensional examples shows the effectiveness of the model to describe dispersive wave propagation and remove singularities in a coupled elasto-magnetic context
increasingchemicalefficiencybymixingdifferentbuffergasesoncoil
为进一步提高氧碘化学激光器效率,提出一种不改变激光器结构,仅变换主副载气的方法。在增益区长度为11.7 cm的激光器上进行实验,以N2,Ar和CO2做为氧碘化学激光器的主载气或副载气,对激光器的输出功率和化学效率进行了研究。实验结果表明,平均分子质量改变对主副气流的混合是有利的,因而可以提高激光器的输出效率。当N2为主载气,Ar为副载气时,激光器输出功率和化学效率最高,分别达到3.09 kW,30.2%
Alignment Condition-Based Robust Adaptive Iterative Learning Control of Uncertain Robot System
This paper proposes an adaptive iterative learning control strategy integrated with saturation-based robust control for uncertain robot system in presence of modelling uncertainties, unknown parameter, and external disturbance under alignment condition. An important merit is that it achieves adaptive switching of gain matrix both in conventional PD-type feedforward control and robust adaptive control in the iteration domain simultaneously. The analysis of convergence of proposed control law is based on Lyapunov's direct method under alignment initial condition. Simulation results demonstrate the faster learning rate and better robust performance with proposed algorithm by comparing with other existing robust controllers. The actual experiment on three-DOF robot manipulator shows its better practical effectiveness
Revealing the Mechanism of Dioxin Formation from Municipal Solid Waste Gasification in a Reducing Atmosphere
Gasification is an effective technology for the thermal disposal of municipal solid waste (MSW) with lower dioxin emission compared to the prevailing incineration process. Nevertheless, the mechanism of dioxin formation in the reducing atmosphere during the gasification process was seldomly explored. Herein, the effects of the atmosphere, temperature, and chlorine source were systematically investigated in terms of dioxin distribution. With CO and HO as gasification agents, a reducing reaction atmosphere was formed with abundant H which effectively suppressed the generation of C-Cl, contributing to a substantial decrease of dioxin concentration by ∼80% compared to the incineration process. The formation of dioxin was favored at temperatures below 700 °C with its peak concentration achieved at 500 °C. It was unveiled that inorganic chlorine played a dominant role in the reducing atmosphere, with a lower proportion of C-O-C/O-C═O on residual slag compared to an oxidizing atmosphere. Additionally, the generated H reduced the concentration of dioxins by attacking C-Cl and inhibiting the crucial Deacon reaction for dioxin formation, validated by density functional theory calculation. Eventually, the formation route paradigm and the reaction mechanism of dioxin formation from MSW gasification were revealed, facilitating and rationally guiding the control of dioxin emission
Representative Volume Element Size and Length Scale Identification in Generalised Magneto-Elasticity
A generalised magneto-elastic continuum model with gradients of strain, magnetic field, and piezo-magnetic coupling terms has been discussed in this study. Characteristic length scale parameters, accompanying the higher order components in the model, have been identified in terms of representative volume element (RVE) sizes, in order to introduce the microstructural information to material properties on the macro-level. Following this qualitative definition, a quantitative determination, and the analysis of RVE sizes in different physical phenomena, a RVE and, hence, length-scale enriched generalised gradient magneto-elastic continuum model has been employed in a benchmark numerical example demonstrating the removal of singularities from magnetic and mechanical fields.</p
increasingchemicalefficiencybymixingdifferentbuffergasesoncoil
为进一步提高氧碘化学激光器效率,提出一种不改变激光器结构,仅变换主副载气的方法。在增益区长度为11.7 cm的激光器上进行实验,以N2,Ar和CO2做为氧碘化学激光器的主载气或副载气,对激光器的输出功率和化学效率进行了研究。实验结果表明,平均分子质量改变对主副气流的混合是有利的,因而可以提高激光器的输出效率。当N2为主载气,Ar为副载气时,激光器输出功率和化学效率最高,分别达到3.09 kW,30.2%
Theabrownin from Wuniuzao Dark Tea Regulates Hepatic Lipid Metabolism and Gut Microbiota in Mice Fed High-Fat Diet
The search for functional foods with no side effects that can alleviate obesity has been a common trend. Wuniuzao dark tea could be a safe choice. This study aimed to explore whether theabrownin from Wuniuzao dark tea could regulate hepatic lipid metabolism and gut microbiota in mice fed a high-fat diet. In total, fifty 8-week-old male C57BL/6 mice were randomly divided into five treatment groups, including a normal control group, high-fat diet group, positive control group, low-dose theabrownin group, and high-dose theabrownin group. After a 9-week intervention, these mice were selected from each treatment group for sampling. The results showed that the body weight and epididymis fat weight of obese mice fed with theabrownin were decreased. Serum total triglycerides, total cholesterol, and low-density lipoprotein cholesterol, and activities of aspartate aminotransferase and alanine aminotransferase were also decreased. Protein and mRNA expression of fatty acid synthesis and lipid production-related genes of mice fed with theabrownin were downregulated. The gut microbiota composition in the theabrownin group was improved. The study indicated that theabrownin from Wuniuzao dark tea could achieve the liver protection and anti-obesity effects by regulating the Srebp lipid metabolism pathway and bile acid metabolism process, and improving the gut microbiota composition of mice
Characterization and Genetic Diversity of <i>Pseudomonas syringae</i> pv. <i>syringae</i> Isolates Associated with Rice Bacterial Leaf Spot in Heilongjiang, China
In China, rice is one of the most important cereal crops. Rice bacterial brown leaf spot caused by P. s. pv. syringae is among the most damaging rice diseases in the Heilongjiang Province of China and results in substantial yield losses. In this study, a comprehensive analysis of the pathogen, population structure, and genetic diversity within the species was performed. For this purpose, 176 bacterial isolates of P. s. pv. syringae collected from 15 locations were characterized by using biochemical tests such as the LOPAT test, and genetic characterizations such as multilocus sequence analysis (MLSA) and repetitive PCR, using BOX, REP and ERIC primers. Biochemical testing and detection of syrB genes confirm the presence of P. s. pv. syringae, genetic characterization by MLSA and genetic fingerprinting by repetitive PCR confirmed that high genetic heterogeneity exists in the P. s. pv. syringae isolates, and clustering of the tested isolates and reference strains are related with the same genomospecies 1. This work contributes to the physiological classification of the P. s. pv. syringae isolated from Heilongjiang Province, China, and the results present new data concerning the phylogeny and genetic diversity. This type of study about P. s. pv. syringae has been not reported from this region until now