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Score-based diffusion models have shown promising results in unpaired image-to-image translation (I2I). However, the existing methods only perform unpaired I2I in pixel space, which requires high computation costs. To this end, we propose guiding stochastic differential equations in latent space (Latent-SDE) that extracts domain-specific and domain-independent features of the image in the latent space to calculate the loss and guides the inference process of a pretrained SDE in the latent space for unpaired I2I. To refine the image in the latent space, we propose a latent time-travel strategy that increases the sampling timestep. Empirically, we compare Latent-SDE to the baseline of the score-based diffusion model on three widely adopted unpaired I2I tasks under two metrics. Latent-SDE achieves state-of-the-art on Cat →Dog and is competitive on the other two tasks. Our code will be freely available for public use upon acceptance at https://github.com/zhangXJ147/Latent-SDE.

Coverage is an essential monitored parameter during the shot peen forming process. However, the conventional manual visual inspection methods suffer from low efficiency and poor accuracy. In this paper, a combined computer vision and image processing method is applied to realize the automatic measurement of shot peening surface coverage, and the critical issues involved, such as shot peening image pre-processing, indentation light spots recognition, shot-peened area segmentation, etc., are systematically investigated. The results indicate that the influence of machining streaks on the subsequent image processing is effectively reduced by adjusting the illumination conditions and adopting the median filtering algorithm. The number and location of indentations in the shot peening surface image are easily obtained by treating the central light spot as an identifier for the indentation. The features of the shot-peened area can be extracted effectively by segmenting the image reconstructed based on the light spots. The effectiveness of the coverage measurement method is verified by shot peen forming experiments, and the accuracy of the measurement results can be over 97 %. The influence of coverage on shot peening deformation is further examined using the results of algorithm processing, which is reflected in that the radius of curvature decreases with the coverage.

Very limited comparative research has been conducted on microstructure evolution induced by different peening methods. Herein, the 2024T351 aluminium alloy was subjected to conventional shot peening (CSP) and ultrasonic shot peening (USP) under the identical Almen height to investigate the differences in surface roughness, residual stress and microhardness. The results demonstrated that under the same Almen height, the CSP treatment resulted in a rougher surface with higher surface roughness and more surface defects, and higher surface and maximum compressive residual stress (CRS) than the USP treatment. In contrast, the CRS depth was relatively lower for the CSP treated samples. In addition, the USP treatment produced more significant microhardness and hardened layer than the CSP treatment.

Very limited comparative research has been conducted on microstructure evolution induced by different peening methods. Herein, the 2024T351 aluminium alloy was subjected to conventional shot peening (CSP) and ultrasonic shot peening (USP) under the identical Almen height to investigate the differences in surface roughness, residual stress and microhardness. The results demonstrated that under the same Almen height, the CSP treatment resulted in a rougher surface with higher surface roughness and more surface defects, and higher surface and maximum compressive residual stress (CRS) than the USP treatment. In contrast, the CRS depth was relatively lower for the CSP treated samples. In addition, the USP treatment produced more significant microhardness and hardened layer than the CSP treatment.

In this paper, a progressive approach to predict the multiple shot peening process parameters for complex integral panel is proposed. Firstly, the invariable parameters in the forming process including shot size, mass flow, peening distance and peening angle are determined according to the empirical and machine type. Then, the optimal value of air pressure for the whole shot peening is selected by the experimental data. Finally, the feeding speed for every shot peening path is predicted by regression equation. The integral panel part with thickness from 2 mm to 5 mm and curvature radius from 3200 mm to 16000 mm is taken as a research object, and four experiments are conducted. In order to design specimens for acquiring the forming data, one experiment is conducted to compare the curvature radius of the plate and stringer-structural specimens, which were peened along the middle of the two stringers. The most striking finding of this experiment is that the outer shape error range is below 3.9%, so the plate specimens can be used in predicting feeding speed of the integral panel. The second experiment is performed and results show that when the coverage reaches the limit of 80%, the minimum feeding speed is 50 mm/s. By this feeding speed, the forming curvature radius of the specimens with different thickness from the third experiment is measured and compared with the research object, and the optimal air pressure is 0.15 MPa. Then, the plate specimens with thickness from 2 mm to 5 mm are peened in the fourth experiment, and the measured curvature radius data are used to calculate the feeding speed of different shot peening path by regressive analysis method. The algorithm is validated by forming a test part and the average deviation is 0.496 mm. It is shown that the approach can realize the forming of the integral panel precisely.

The phase equilibria of the Ni–Nb–V ternary system at 1 000 °C and 1 200 °C were established using electron probe microanalysis, X-ray diffraction and differential scanning calorimetry. The results of the investigation revealed that: (1) The Nb solubility in (Ni) and σ′ phases was less than 10 at.%; (2) A ternary compound τ (NiNbV) was confirmed, in which V had a large solubility; (3) A new liquid region was evident at 1 200 °C, but was absent at 1 000 °C; (4) The lattice constants of Ni3Nb and Ni6Nb7phase decreased with increase in V content in the Ni3Nb and Ni6Nb7. The phase equilibria of the Ni–Nb–V ternary system will contribute to its thermodynamic assessment.

OBJECTIVE To perform a systematic exploration of the phenomenon of mobilization of circulating angiogenic cells (CACs) in an animal model. This phenomenon has been observed in patients with cutaneous burn wounds and may be an important mechanism for vasculogenesis in burn wound healing. DESIGN We used a murine model, in which burn depth can be varied precisely, and a validated culture method for quantifying circulating CACs. SETTING Michael D. Hendrix Burn Research Center, Baltimore, Maryland. PARTICIPANTS Male 129S1/SvImJ mice, aged 8 weeks, and 31 patients aged 19-59 years with burn injury on 1% to 64% of the body surface area and evidence of hemodynamic stability. MAIN OUTCOME MEASURES Burn wound histological features, including immunohistochemistry for blood vessels with CD31 and α-smooth muscle actin antibodies, blood flow measured with laser Doppler perfusion imaging, and mobilization of CACs into circulating blood measured with a validated culture technique. RESULTS Increasing burn depth resulted in a progressive delay in the time to mobilization of circulating CACs and reduced mobilization of CACs. This delay and reduction in CAC mobilization was associated with reduced perfusion and vascularization of the burn wound tissue. Analysis of CACs in the peripheral blood of the human patients, using a similar culture assay, confirmed results previously obtained by flow cytometry, that CAC levels peak early after the burn wound. CONCLUSION If CAC mobilization and wound perfusion are important determinants of clinical outcome, then strategies designed to augment angiogenic responses may improve outcome in patients with severe burn wounds. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00796627Arch Surg. 2010;145(3):259-266--