The maturity of Korla fragrant pears directly influences their harvesting, packaging, transportation, and storage. Investigating the mechanical properties of fragrant pears at various maturity stages can help minimize damage during postharvest handling. This study employs micro-CT technology combined with reverse model scanning to develop a numerical model for force damage across different maturity stages, supported by experimental validation. The results demonstrate that both rupture force and rupture strain progressively decrease as the maturity of Korla fragrant pears increases, exhibiting a sudden transition. Simultaneously, the fruit’s microstructure shifts from distinct cellular organization to an irregular, collapsed state. The proposed numerical model, which accounts for this abrupt change, provides a better fit than models based on a single physical parameter, with the R² value improving from 0.7922 to 0.9665. Furthermore, this model accurately quantifies the mechanical properties of fragrant pears at all stages of maturity. These findings offer technical support for reducing postharvest losses and serve as a reference for developing damage prediction models for other fruits and vegetables.

In the postharvest supply chain, directly moving Korla fragrant pears from ice temperature storage to ambient display readily induces quality deterioration, shortens shelf life, and causes substantial economic losses. Using Korla fragrant pears as the study system, we propose a gradual rewarming protocol. We optimised temperature and time parameters with response surface methodology and validated the protocol by comparing changes in shelf-life quality and microstructure under gradual versus direct rewarming. Results indicate that rewarming at 6 °C for 12 h is the optimal condition for maintaining overall postharvest quality. Under these conditions, gradient rewarming significantly improved physical and chemical quality. Compared with direct rewarming, weight loss decreased by 2.6 percent, firmness increased to 4.23 kg/cm², the peak soluble solids content reached 12.5%, the respiratory peak was delayed and the rate slowed, and shelf life was extended by about 80%. Microstructural verification showed a more compact cellular arrangement, reduced intercellular spaces, and the mildest degree of cell collapse in pears subjected to gradient rewarming. The proposed gradient rewarming protocol provides theoretical and practical guidance for optimising temperature control strategies across the postharvest cold chain and retail stages for Korla fragrant pears.

Shell–kernel separation is a critical stage in walnut processing; however, the presence of kernel loss and shell retention during separation markedly limits overall performance. In this study, discrete element method (DEM) simulations were conducted using EDEM 2022 software, in conjunction with experimental validation, to investigate the vibratory screening behavior of walnut shell–kernel mixtures under varying vibration frequencies and sieve surface inclinations. The underlying mechanisms of kernel loss and shell retention were elucidated by analyzing particle kinematics and contact characteristics, including velocity, collision frequency, and contact force on the sieve surface. The results indicate that both cleaning rate and loss rate exhibited an increasing trend with increasing sieve inclination. In contrast, as vibration frequency increases, the cleaning rate decreases while the loss rate increases. These findings reveal an inherent and irreconcilable trade-off between cleaning efficiency and material loss when solely adjusting operating parameters. Even under the selected operating conditions (vibration frequency of 14 Hz and screen inclination of 16°), the cleaning rate reached only 93.14% and 93.44%, while the loss rate remained as high as 14.74% and 19.92%, respectively. Mechanistically, kernel loss is primarily attributed to frequent particle–particle collisions during transport, which reduce kernel velocity and may even induce reverse motion, preventing effective recovery. Shell retention, however, arises from early-stage entrainment within dense particle beds and subsequent collision-driven migration toward the kernel outlet, ultimately hindering complete separation. Based on these mechanisms, an airflow-assisted reduction strategy was proposed and experimentally validated. Compared with the optimal single-factor operating conditions, the proposed strategy improved the cleaning rate by 2.04 and 1.74 percentage points and reduced the loss rate by 6.59 and 11.77 percentage points. These findings provide valuable references for the design and optimization of mechanized sorting equipment.

In response to the urgent need for full-process mechanization in Xinjiang’s cotton–cumin intercropping system, and to address the prominent bottlenecks of missing equipment for key harvesting steps and reliance on manual operations, we developed a cumin harvester and investigated its operating mechanisms. Guided by the agronomic parameters of the intercropping system, we executed a system-level design centered on the header unit, performed multi-objective optimization using orthogonal experiments and regression modeling, and conducted field validation. Results show: stubble height of 32.6 mm, harvester reel speed of 28 r/min, and forward speed of 3.26 km/h. Under this parameter configuration, the harvest rate was 89.54%, and the average damage rate was 7.33%. Field trials indicated a harvest rate of 88.2% and an average damage rate of 5.6%, with deviations from model predictions of 1.34% and 1.73%. The optimal reel index (λ = 1.69), the longitudinal component of the reel tine motion, prevents repeated impacts on the plants, reducing shattering and threshing damage; the axial component provide reliable support and smooth guidance to the stalks, ensuring continuous, steady cutting; the optimized stubble height is lower than the plant’s center of mass.

The crushing of used drip irrigation tape is a crucial step in the recycling and reuse of drip irrigation tapes. Incomplete crushing and low efficiency are among the main factors restricting its reprocessing. Investigating the fracture characteristics and the mechanism of fracture during the crushing process is key to solving this problem. Therefore, this study constructs a stretching fracture platform to investigate the influence of stretching speed on the fracture characteristics and reveals the fracture mechanism by analyzing fracture morphology, force-displacement curves, fracture energy, and microstructure. The results show that as the speed increases, the limit strain decreased from 117.7% to 38.7%, and the fracture location always occurs at the junction between the necked and non-necked area, the fracture mode transitions from ductile fracture to brittle fracture, the deformation mode shifts from being dominated by elastoplastic deformation to being dominated by elastic deformation, and the mechanical response curve changes from five stages to three stages. When the stretching speed increases from 60 mm/s to 70 mm/s, a jump phenomenon is observed in macroscopic and microscopic. As the speed increases, the total energy absorbed by the drip irrigation tape decreases from 1.29 × 10⁻² J/mm³ to 0.39 × 10⁻² J/mm³. Brittle fracture primarily absorbs energy for the disintegration and fracture of lamellae in the spherulites at the fracture surface. Ductile fracture primarily absorbs energy for the extension of the fibrous structure, and the mechanical properties of the necked area are strengthened, which leads to the fracture location always occurring at the junction between the necked and non-necked area.