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The low-velocity impact and compression after the impact of the composite stiffened panels were carried out after damp-heat aging. The experimental results show that reinforcing the ribs can enhance the impact resistance of test pieces after damp-heat aging. After impacting, the specimens were tested in an axial compression. The results show that the ultimate bearing capacity of the specimen is also affected by different located positions of the impact and different aging times. Compared with the intact specimen, the ultimate load-bearing capacity was reduced to 16.83, 12.10, and 17.10% with the specimen aging for 0, 45, and 90 days, respectively, while the impact position located at the intersection of longitudinal and transverse bars has the greatest influence on the damp-heat aging of specimens.

Three-dimensional braided composites (3D-BCs) have better specific strength and stiffness than two-dimensional planar composites (2D-PCs), so they are widely used in modern industrial fields. In this paper, two kinds of 3D four-directional braided composites (3D4d-BCs) with different braided angles (15°, denoted as H15, and 30°, denoted as H30) were subjected to hydrothermal aging treatments, low-velocity impact (LVI) tests, and compression after impact (CAI) tests under different conditions. This study systematically studied the hygroscopic behavior and the effect of hygrothermal aging on the mechanical properties of 3D4d-BC. The results show that higher temperatures and smaller weaving angles can significantly improve the moisture absorption equilibrium content. When the moisture absorption content is balanced, the energy absorption effect of 3D4d-BC is better, but the integrity and residual compression rate will be reduced. Due to the intervention of oxygen molecules, the interface properties between the matrix and the composite material will be reduced, so the compressive strength will be further reduced. In the LVI test, the peak impact load of H15 is low. In CAI tests, the failure of H15 mainly occurs on the side, and the failure form is buckling failure. The main failure direction of H30 is 45° shear failure.

Objective: To survey asthma prevalence, correlation factors for prevention, treatment, and for policy decision of asthma control., Methods: Done with TB epidemiological survey synchronously, sampling by stratified-cluster-random method. 43 points were selected and distributed in all 18 prefectures in Henan province. Sampling population was 75 134, and 65 033 (97.0%) were investigated actually., Results: In this survey, 682 asthma patients were found. The total prevalence rate was 1.05%, the rate for children was 1.71%, and that for adult was 0.82%; the rates for male and female were 1.16%, 0.94% respectively. The ratio of male to female was 1.23:1. When asthmatic chronic bronchitis cases were regarded as asthma cases and included in total asthma cases, the overall prevalence rate of asthma would increase up to 1.73%, raised by 65%. The higher prevalence were in 0 approximately 3 years old age group (4.48%) and >/= 65 years old age group (1.43%), the lowest prevalence was in 15 approximately 24 years old age group (0.36%). For 90% of asthmatic children, the initiative age of asthma was before 7 years old, and for 1/3 adult patient, it was in childhood. The prevalence of asthma in rural area was higher than that of urban area. Cold air, common cold, stimulation of smoking and cooking, and room dust were the 4 main inducing factors. Seasonal attack of asthma accounted for 67.2%, and that in winter and spring was 65.4%. 60.6% of asthma cases showed history of allergic diseases including allergic rhinitis, dermatitis, and drug allergy; 34.3% asthma family history., Conclusions: The rate of prevalence and inducing factors of asthma in Henan province were gained in this survey. The results may basically reflect the present status and be provided for asthma control as reference. According to the prevalence, asthma cases would be up to 0.98 approximately 1.6 million in whole Henan province and more attention should be paid to this situation.