Abstract
High-speed motion control of the galvanometer has become a very important part of laser processing. Due to the parameter uncertainty of the galvanometer itself, non-linearity can affect the ...friction compensation effect. In this paper, we propose to reduce the steady-state tracking error of the galvanometer system by means of an integral control term, while estimating the friction behavior using a nonlinear modified LuGre observer. Then an adaptive integral robust control scheme is used to eliminate the effects of nonlinear friction and external disturbances. And the stability of the galvanometer system is proved by the Lyapunov theorem. Simulation verification by MATLAB shows that the control scheme proposed in this paper can accurately follow the system commands. And the controller can effectively suppress the effects of unknown disturbances and parameter uncertainties compared with traditional control strategies. The simulation results show that the proposed control scheme significantly improves the response speed and tracking accuracy of the galvanometer system.
Transcription factors (TFs) play an important role in tumors. We integrated and analyzed 13 GPL570 platform gastric cancer (GC) microarrays, identified 10 independent prognostic TFs, and constructed ...a GC prognostic model. Using GSE26942 as the verification set, the Kaplan-Meier curve showed that the signature distinguish the survival rate of GC patients (P < 0.01), and the AUC values are 0.746 and 0.630, respectively. Compared with the clinicopathological characteristics, the signature is an independent prognostic factor (P < 0.05). A nomogram was established based on the model, and the five-year calibration curve verified that the prediction of the nomogram was almost consistent with the actual survival rate, C-index of 0.747 indicated a moderate prognostic ability. The analysis of target genes of 10 TFs showed that they are closely related to the progression of GC. External database and rt-PCR showed that the RNA and protein expression of TFs are consistent with our analysis.
•Integrating the GPL570 platform 13 gastric cancer micro-arrays to get 1027 samples.•Transcription factors differentially expressed in gastric cancer were identified.•The prognostic-related TFs were identified and a prognostic model was constructed.•The target genes of hub TFs were predicted and the molecular mechanism was analyzed.•The critical TFs have been verified by external databases and experiments.
In this paper, the types, formation time, structural morphology, and influence of steel corrosion products in seawater and sea-sand concrete were studied, and the intermediate and final products of ...steel corrosion under different conditions were determined. The corrosion products of steel in these concrete specimens under two curing methods were studied separately by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). Due to the presence of a large amount of chloride ions in the concrete, the rust layer on the surface of a steel bar contained many intermediates, such as lepidocrocite (γ–FeOOH) and aka-ganeite (β–FeOOH). Under wet/dry cycles, with the addition and loss of moisture in concrete, various corrosion products were also dynamically converted into each other. In the specimens immersed in seawater for a long time, the intermediates of corrosion were lepidocrocite (γ–FeOOH) and aka-ganeite (β–FeOOH), which were substituted for oxygen as the new depolarizers of cathode reduction reaction, and consumed themselves to ensure smooth corrosion.
Gene flow is an important evolutionary force that enables adaptive responses of plant pathogens in response to changes in the environment and plant disease management strategies. In this study, we ...made a direct inference concerning gene flow in the Irish famine pathogen Phytophthora infestans between two of its hosts (potato and tomato) as well as between China and India. This was done by comparing sequence characteristics of the eukaryotic translation elongation factor 1 alpha (eEF‐1α) gene, generated from 245 P. infestans isolates sampled from two countries and hosts. Consistent with previous results, we found that eEF‐1α gene was highly conserved and point mutation was the only mechanism generating any sequence variation. Higher genetic variation was found in the eEF‐1α sequences in the P. infestans populations sampled from tomato compared to those sampled from potato. We also found the P. infestans population from India displayed a higher genetic variation in the eEF‐1α sequences compared to China. No gene flow was detected between the pathogen populations from the two countries, which is possibly attributed to the geographic barrier caused by Himalaya Plateau and the minimum cross‐border trade of potato and tomato products. The implications of these results for a sustainable management of late blight diseases are discussed.
The theory of Pólya ensembles of positive definite random matrices provides structural formulas for the corresponding biorthogonal pair, and correlation kernel, which are well suited to computing the ...hard edge large N asymptotics. Such an analysis is carried out for products of Laguerre ensembles, the Laguerre Muttalib-Borodin ensemble, and products of Laguerre ensembles and their inverses. The latter includes, as a special case, the Jacobi unitary ensemble. In each case, the hard edge scaled kernel permits an expansion in powers of 1/N, with the leading term given in a structured form involving the hard-edge scaling of the biorthogonal pair. The Laguerre and Jacobi ensembles have the special feature that their hard edge scaled kernel - the Bessel kernel - is symmetric and this leads to there being a choice of hard edge scaling variables for which the rate of convergence of the correlation functions is
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Hawking radiation is one of the quantum features of a black hole that can be understood as a quantum tunneling across the event horizon of the black hole, but it is quite difficult to directly ...observe the Hawking radiation of an astrophysical black hole. Here, we report a fermionic lattice-model-type realization of an analogue black hole by using a chain of 10 superconducting transmon qubits with interactions mediated by 9 transmon-type tunable couplers. The quantum walks of quasi-particle in the curved spacetime reflect the gravitational effect near the black hole, resulting in the behaviour of stimulated Hawking radiation, which is verified by the state tomography measurement of all 7 qubits outside the horizon. In addition, the dynamics of entanglement in the curved spacetime is directly measured. Our results would stimulate more interests to explore the related features of black holes using the programmable superconducting processor with tunable couplers.
Entrainment at the top of the planetary boundary layer (PBL) is of significant importance because it controls the upward growth of the PBL height. An option called ysu_topdown_pblmix, which provides ...a parameterization of fog-top entrainment, has been proposed for valley fog modeling and introduced into the YSU (Yonsei University) PBL scheme in the Weather Research and Forecasting (WRF) model. However, enabling this option in simulations of sea fog over the Yellow Sea typically results in unrealistic dissipation near the fog bottom and even within the entire fog layer. In this study, we theoretically examine the composition of the option ysu_topdown_pblmix, and then argue that one term in this option might be redundant for sea-fog modeling. The fog-top variables are employed in this term to determine the basic entrainment in the dry PBL, which is already parameterized by the surface variables in the original YSU PBL scheme. This term likely leads to an overestimation of the fog-top entrainment rate, so we refer to it as redundant. To explore the connection between the redundant term and unrealistic dissipation, a widespread sea-fog episode over the Yellow Sea is employed as a case study based on the WRF model. The simulation results clearly attribute the unrealistic dissipation to the extra entrainment rate that the redundant term induces. Fog-top entrainment is unexpectedly overestimated due to this extra entrainment rate, resulting in a significantly drier and warmer bias within the interior of sea fog. When sea fog develops and reaches a temperature lower than the sea surface, the sea surface functions as a warming source to heat the fog bottom jointly with the downward heat flux brought by the fog-top entrainment, leading the dissipation to initially occur near the fog bottom and then gradually expand upwards. We suggest a straightforward method to modify the option ysu_topdown_pblmix for sea-fog modeling that eliminates the redundant term. The improvement effect of this method was supported by the results of sensitivity tests. However, more sea-fog cases are required to validate the modification method.
The rubber tree, Hevea brasiliensis, produces natural rubber that serves as an essential industrial raw material. Here, we present a high-quality reference genome for a rubber tree cultivar GT1 using ...single-molecule real-time sequencing (SMRT) and Hi-C technologies to anchor the ∼1.47-Gb genome assembly into 18 pseudochromosomes. The chromosome-based genome analysis enabled us to establish a model of spurge chromosome evolution, since the common paleopolyploid event occurred before the split of Hevea and Manihot. We show recent and rapid bursts of the three Hevea-specific LTR-retrotransposon families during the last 10 million years, leading to the massive expansion by ∼65.88% (∼970 Mbp) of the whole rubber tree genome since the divergence from Manihot. We identify large-scale expansion of genes associated with whole rubber biosynthesis processes, such as basal metabolic processes, ethylene biosynthesis, and the activation of polysaccharide and glycoprotein lectin, which are important properties for latex production. A map of genomic variation between the cultivated and wild rubber trees was obtained, which contains ∼15.7 million high-quality single-nucleotide polymorphisms. We identified hundreds of candidate domestication genes with drastically lowered genomic diversity in the cultivated but not wild rubber trees despite a relatively short domestication history of rubber tree, some of which are involved in rubber biosynthesis. This genome assembly represents key resources for future rubber tree research and breeding, providing novel targets for improving plant biotic and abiotic tolerance and rubber production.
This study reports a chromosome-based genome for rubber tree and provides novel insight into the spurge chromosome evolution. Moreover, it is found that genes is associated with the rubber biosynthesis relevant to latex production are significantly expanded in rubber tree. A number of candidate domestication genes are also identified, some of which are associated with rubber biosynthesis in cultivated rubber trees.
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