Research on trajectory tracking control for wet clutch engagement based on SMC

AbstractTo improve tracking control quality of the clutch actuator during the wet clutch engagement, models of the clutch actuator were established firstly, including the control cylinder model, flow equilibrium equation and pressure control model. Secondly, taking the clutch output speed as tracking target, the state space equation of the tracking control system was set up and the sliding mode controller (SMC) was designed. Finally, a simulation test was performed. The results show that a higher tracking accuracy as well as a better performance to resist disturbance can be achieved with the proposed sliding control method, compared to PI control. It was also shown that the exponent approaching sliding mode control can produce smaller chattering compared with the constant rate approaching sliding mode control

Chemical components of volatile oil from Cinnamomum jensenianum Hand Mazz leaf in Yongzhou, and its antibacterial and antioxidant properties

Purpose: To study the chemical components, and in vitro antibacterial and antioxidant properties of volatile oil extracted from Yongzhou Cinnamomum jensenianum Hand. Mazz leaves.Methods: The extraction process of volatile oil in the leaves of Yongzhou Cinnamomum jensenianum Hand. Mazz was optimized with respect to volatile oil yield, and the oil was subjected to gas chromatography-mass spectrometry (GC-MS) analysis. In vitro antimicrobial activities against bacteria and fungi were evaluated by the filter paper method, while in vitro antioxidant potential was determined by assaying its ability to scavenge DPPH radicals.Results: The optimized extraction conditions for volatile oil from the leaves of Yongzhou Cinnamomum jensenianum Hand. Mazz were 3.5 h extraction time, solid-liquid ratio of 1:10, and soaking time of 4 h, which resulted in volatile oil yield of 2.4 ± 0.19 %. A total of 37 components were isolated and identified, accounting for 99.19 % of the volatile oil. The in vitro antimicrobial activities against bacteria and fungi were significant, with minimum inhibitory concentration (MIC) between 10 and 20 uL. At a volatile oil concentration of 0.09 mg/mL, the DPPH scavenging ability of the oil was stronger than that of BHT.Conclusion: There is a high level of extractability of volatile oil from the leaves of Yongzhou Cinnamomum jensenianum Hand. Mazz. The main component is linalool (94.45 %), and it has good antibacterial and antioxidant properties.Keywords: Yongzhou Cinnamomum jensenianum Hand. Mazz, Volatile oil, Antibacterial, Antioxidan

RESEARCH ON THE MOTION RESPONSE OF AQUACULTURE SHIP AND TANK SLOSHING UNDER ROLLING RESONANCE

The double-row and double-chamfered aquaculture tank is a special tank structure of the aquaculture ship. The tank sloshing of this structure is coupled with the hull motion, which has an important impact on the safety of the hull motion. In the present study, research on the tank sloshing and hull motion response of aquaculture ships was conducted based on the model seakeeping and tank sloshing tests in regular waves. The test results were compared with the numerical simulation results of solid loading without sloshing. The results showed that the numerical simulation of the pitch motion was consistent with the amplitude-frequency response curve of the experimental results. Under certain transverse wave conditions, a large discrepancy existed between the amplitude-frequency response curve of the heave motion by the numerical simulation and the test results, and the roll motion differed most from the experimental result. Severe roll resonance occurred when the wave length-ship length ratio was 0.6. The roll motion amplitude was increased by 183.2%. Therefore, compared with aquaculture ships without sloshing, the sloshing of the tank has little effect on the pitch but has a great impact on the roll and heave motions, with the most significant effect on the roll motion

Process optimization and insecticidal activity of alkaloids from the root bark of Catalpa ovata G. Don by response surface methodology

Purpose: To optimize the extraction of total alkaloids from the root bark of Catalpa ovata using response surface methodology, and to determine the insecticidal activity of the total alkaloids extracted. Methods: A combination of Box-Behnken design and response surface methodology  (RSM) was used to optimize the acid water extraction of total alkaloids from the root bark of Catalpa ovata, with extraction rate of total alkaloids as index and the single factor experiment as basis, and the extraction time, material: liquid ratio and pH as 3 factors. The insecticidal activity of total alkaloids was determined against the three instar armyworm Mythimna separata (Lepidoptera: Noctuidae) and  diamondback moth Plutella xylostella (Lepidoptera: Plutellidae).Results: The optimum extraction conditions for total alkaloids were: material: liquid ratio of 1:10; extraction time of 3 h, pH of 1.0, and simmering. Under these  conditions, total alkaloid extraction was 8.62 %, which was very close to the experimental value. The results were accurate and reliable, with reference value. The insecticidal activity of the total alkaloids indicate that when the concentration of the total alkaloids was 10 mg/L, the fatality rate of Plutella xyllostella and oriental armyworm was over 89 %, but the insecticidal activity of the total alkaloids was lower than that of avermectin which was employed as a reference.Conclusion: The alkaloids from the root bark of Catalpa ovata are potential botanical insecticides.Keywords: Catalpa ovata, Root bark, Total alkaloids, Response surface  methodology, Insecticidal activit

A Study of Neural Collapse Phenomenon: Grassmannian Frame, Symmetry, Generalization

In this paper, we extends original Neural Collapse Phenomenon by proving Generalized Neural Collapse hypothesis. We obtain Grassmannian Frame structure from the optimization and generalization of classification. This structure maximally separates features of every two classes on a sphere and does not require a larger feature dimension than the number of classes. Out of curiosity about the symmetry of Grassmannian Frame, we conduct experiments to explore if models with different Grassmannian Frames have different performance. As a result, we discover the Symmetric Generalization phenomenon. We provide a theorem to explain Symmetric Generalization of permutation. However, the question of why different directions of features can lead to such different generalization is still open for future investigation.Comment: 25 pages, 2 figure

A thermal bonding method for manufacturing Micromegas detectors

For manufacturing Micromegas detectors, the "bulk" method based on photoetching, was successfully developed and widely used in nuclear and particle physics experiments. However, the complexity of the method requires a considerable number of advanced instruments and processing, limiting the accessibility of this method for production of Micromegas detectors. In view of these limitations with the bulk method, a new method based on thermal bonding technique (TBM) has been developed to manufacture Micromegas detectors in a much simplified and efficient way without etching. This paper describes the TBM in detail and presents performance of the Micromegas detectors built with the TBM. The effectiveness of this method was investigated by testing Micromegas detector prototypes built with the method. Both X-rays and electron beams were used to characterize the prototypes in a gas mixture of argon and CO2 (7%). A typical energy resolution of ~16% (full width at half maximum, FWHM) and an absolute gain greater than 10^4 were obtained with 5.9 keV X-rays. Detection efficiency greater than 98% and a spatial resolution of ~65 {\mu}m were achieved using a 5 GeV electron beam at the DESY test-beam facility. The gas gain of a Micromegas detector could reach up to 10^5 with a uniformity of better than 10% when the size of the avalanche gap was optimized thanks to the flexibility of the TBM in defining the gap. Additionally, the TBM facilitates the exploration of new detector structures based on Micromegas owing to the much-simplified operation with the method.Comment: 15 pages, 17 figure

The HIF-1 Hypoxia-Inducible Factor Modulates Lifespan in C. elegans

During normal development or during disease, animal cells experience hypoxic (low oxygen) conditions, and the hypoxia-inducible factor (HIF) transcription factors implement most of the critical changes in gene expression that enable animals to adapt to this stress. Here, we examine the roles of HIF-1 in post-mitotic aging. We examined the effects of HIF-1 over-expression and of hif-1 loss-of-function mutations on longevity in C. elegans, a powerful genetic system in which adult somatic cells are post-mitotic. We constructed transgenic lines that expressed varying levels of HIF-1 protein and discovered a positive correlation between HIF-1 expression levels and lifespan. The data further showed that HIF-1 acted in parallel to the SKN-1/NRF and DAF-16/FOXO transcription factors to promote longevity. HIF-1 over-expression also conferred increased resistance to heat and oxidative stress. We isolated and characterized additional hif-1 mutations, and we found that each of 3 loss-of-function mutations conferred increased longevity in normal lab culture conditions, but, unlike HIF-1 over-expression, a hif-1 deletion mutation did not extend the lifespan of daf-16 or skn-1 mutants. We conclude that HIF-1 over-expression and hif-1 loss-of-function mutations promote longevity by different pathways. These data establish HIF-1 as one of the key stress-responsive transcription factors that modulate longevity in C. elegans and advance our understanding of the regulatory networks that link oxygen homeostasis and aging

Induction of ROS generation and NF-κB activation in MARC-145 cells by a novel porcine reproductive and respiratory syndrome virus in Southwest of China isolate

Each ORF gene nucleotide sequence of YN-2011

Characterization of nonstructural protein 3 of a neurovirulent Japanese encephalitis virus strain isolated from a pig

<p>Abstract</p> <p>Background</p> <p>Japanese encephalitis virus (JEV), as a re-emerging virus that causes 10,000-15,000 human deaths from encephalitis in the world each year, has had a significant impact on public health. Pigs are the natural reservoirs of JEV and play an important role in the amplification, dispersal and epidemiology of JEV. The nonstructural protein 3 (NS3) of JEV possesses enzymatic activities of serine protease, helicase and nucleoside 5'-triphosphatase, and plays important roles in viral replication and pathogenesis.</p> <p>Results</p> <p>We characterized the NS3 protein of a neurovirulent strain of JEV (SH-JEV01) isolated from a field-infected pig. The NS3 gene of the JEV SH-JEV01 strain is 1857 bp in length and encodes protein of approximately 72 kDa with 99% amino acid sequence identity to that of the representative immunotype strain JaGAr 01. The NS3 protein was detectable 12 h post-infection in a mouse neuroblastoma cell line, Neuro-2a, and was distributed in the cytoplasm of cells infected with the SH-JEV01 strain of JEV. In the brain of mice infected with the SH-JEV01 strain of JEV, NS3 was detected in the cytoplasm of neuronal cells, including pyramidal neurons of the cerebrum, granule cells, small cells and Purkinje cells of the cerebellum.</p> <p>Conclusions</p> <p>The NS3 protein of a neurovirulent strain of JEV isolated from a pig was characterized. It is an approximately 72 kDa protein and distributed in the cytoplasm of infected cells. The Purkinje cell of the cerebellum is one of the target cells of JEV infection. Our data should provide some basic information for the study of the role of NS3 in the pathogenesis of JEV and the immune response.</p

A Python Code for Simulating Single Tactile Receptors and the Spiking Responses of Their Afferents

This work presents a pieces of Python code to rapidly simulate the spiking responses of large numbers of single cutaneous tactile afferents with millisecond precision. To simulate the spike responses of all the major types of cutaneous tactile afferents, we proposed an electromechanical circuit model, in which a two-channel filter was developed to characterize the mechanical selectivity of tactile receptors, and a spike synthesizer was designed to recreate the action potentials evoked in afferents. The parameters of this model were fitted using previous neurophysiological datasets. Several simulation examples were presented in this paper to reproduce action potentials, sensory adaptation, frequency characteristics and spiking timing for each afferent type. The results indicated that the simulated responses matched previous neurophysiological recordings well. The model allows for a real-time reproduction of the spiking responses of about 4,000 tactile units with a timing precision of &lt;6 ms. The current work provides a valuable guidance to designing highly realistic tactile interfaces such as neuroprosthesis and haptic device