Full Aperture CO 2

An improved method is presented to scan the full-aperture optical surface rapidly by using galvanometer steering mirrors. In contrast to the previous studies, the scanning velocity is faster by several orders of magnitude. The velocity is chosen to allow little thermodeposition thus providing small and uniform residual stress. An appropriate power density is set to obtain a lower processing temperature. The proper parameters can help to prevent optical surface from fracturing during operation at high laser flux. S-on-1 damage test results show that the damage threshold of scanned area is approximately 40% higher than that of untreated area

Crop rotation and native microbiome inoculation restore soil capacity to suppress a root disease

14 páginas.- 5 figuras.- 58 referencias.- Supplementary information The online version contains supplementary material available at https://doi.org/10.1038/s41467-023-43926-4.It is widely known that some soils have strong levels of disease suppression and prevent the establishment of pathogens in the rhizosphere of plants. However, what soils are better suppressing disease, and how management can help us to boost disease suppression remain unclear. Here, we used field, greenhouse and laboratory experiments to investigate the effect of management (monocropping and rotation) on the capacity of rhizosphere microbiomes in suppressing peanut root rot disease. Compared with crop rotations, monocropping resulted in microbial assemblies that were less effective in suppressing root rot diseases. Further, the depletion of key rhizosphere taxa in monocropping, which were at a disadvantage in the competition for limited exudates resources, reduced capacity to protect plants against pathogen invasion. However, the supplementation of depleted strains restored rhizosphere resistance to pathogen. Taken together, our findings highlight the role of native soil microbes in fighting disease and supporting plant health, and indicate the potential of using microbial inocula to regenerate the natural capacity of soil to fight disease. © 2023, The Author(s).This research was supported by the National Key Research and Development Program of China 2022YFD2201900 (Xi.L.), the National Natural Science Foundation of China 32122056, 42011045 (Xi.L.), and the earmarked fund for CARS-13 (X.W.). M.D-B. acknowledges support from TED2021-130908B-C41/AEI/10.13039/501100011033/Unión Europea NextGenerationEU/PRTR and from the Spanish Ministry of Science and Innovation for the I + D + i project PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033.Peer reviewe

Research on Measurement of Tooth Profile Parameters of Synchronous Belt Based on Point Cloud Data

Accurately detecting the tooth profile parameters of the synchronous belt is crucial for the transmission’s load distribution and service life. However, the existing detection methods have low efficiency, are greatly affected by the manual experience, and cannot realize automatic detection. A measurement method based on point cloud data is proposed to solve this issue. The surface space points of the synchronous belt are acquired by a line-structured light sensor, and the raw point clouds are preprocessed to remove outliers and reduce the number of points. Then, the point clouds are divided into plane and arc regions, and different methods are used for fitting. Finally, the parameters of each tooth are calculated. The experimental results show that the method has high measurement accuracy and reliable stability and can replace the original detection method to realize automatic detection

Hydrocarbon migration characteristics and its controlling effect on hydrocarbon accumulation of weathering crust in slope area of Liaoxi Uplift

With the improvement of the exploration degree, small complex fault block traps have become the key field of oil and gas exploration in the current uplift area. To clarify the reasons for the differential enrichment of oil and gas in the fault block trap in the West Liaoning uplift, the characteristics of weathering crust on the top of the buried hill in the uplift slope area are analysed by using three-dimensional seismic, logging, thin section and other data through three-dimensional streamline quantitative simulation. The "crust-fault" coupling migration model is established to describe the dominant migration path of oil and gas in the slope area to clarify the control effect of hydrocarbon migration along weathered crust on the differential enrichment of oil and gas in the convex fault block. The results show that ① the buried hill in the study area has experienced multistage tectonic movements, and the lithology of the buried hill is mainly lower Paleozoic carbonate rock and Archean granite. The lithology is brittle and easily weathered and denuded. The denudation pores and structural fractures of the weathering crust are widely developed and stably distributed, forming the main channel of lateral long-distance migration of oil and gas in the slope area. ② The middle zone of the slope is controlled by reverse faults to forma fault uplift structure. The migration of oil and gas along the weathering crust is blocked by the slope fault uplift zone, forming a "crust-fault" coupling oil and gas migration model. The fault throw of the fault uplift zone controls the lateral migration ability of oil and gas in the weathering crust. ③ Using the method of three-dimensional streamline quantitative simulation, the four-level dominant oil and gas migration channels in the study area are characterized, and the control effect of different levels of oil and gas migration channels on the degree of oil and gas enrichment in convex fault blocks is clarified. The research results effectively guide the practice of oil and gas exploration in the Liaoxi Uplift and fill the gap of the understanding and research method of oil and gas accumulation in mature uplift areas of oil-rich sags

Investigation of Control of Residual Stress Induced by CO 2 Laser-Based Damage Mitigation of Fused Silica Optics

A CO 2 laser-based annealing technique for the mitigation of damaged sites of fused silica is studied to suppress the residual stress left on the surface. The laser annealing by a linear decrease of the CO 2 laser power effectively reduces the residual stress. The residual stress of mitigated sites is characterized by polarimetry, the reduction of the maximum retardance around the mitigated sites with the exposure time of laser annealing fits a stretched exponential equation, and the maximum retardance with optimal laser annealing is reduced (36 ± 3)% compared to that without laser annealing. The residual stress regions are destructively characterized by introducing damage. The critical size of damage leading to fracture propagation for the mitigated sites without laser annealing is in the range of 120∼230 m, and the corresponding critical size of damage for the mitigated sites with laser annealing is larger than 600 m. According to the relationship between maximum damage size and critical stress, the residual stress without laser annealing is in the range of 28-39 MPa and the residual stress with laser annealing is less than 17 MPa. These results indicate that the CO 2 laser-based annealing technique has a positive effect on the control of residual stress induced by CO 2 laser-based damage mitigation

Defects-Induced Hot Spots in TATB

We investigate the interaction between the laser and energetic materials with different defects. The three-dimensional models of triaminotrinitrobenzene (TATB) explosives containing spherical pores, craters, and cracks are established, respectively. The laser ignition process of TATB is simulated with three-dimensional finite difference time domain (3D-FDTD) method to study the electromagnetic field distribution surrounding these defects with 355 nm laser incidence. It indicates that the larger defects in the TATB energetic materials have the stronger electric field modulations to initial incident laser for all the three defects, which is easier to lead to the generation of hot spots. Furthermore, TATB materials with spherical pore defects and crater defects are easier to form hot spots than those with narrow crack defects