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The plant height, stem diameter, fresh weight, dry weight, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of five oat varieties introduced and planted in saline-alkali land of Songnen Plain after spring sowing were measured, and the correlation research was carried out to evaluate the production adaptability of different oat varieties in Songnen Plain. The results showed that the plant height, fresh weight and dry weight of Wild horse were 121 cm, 5 534 kg/hm² and 1 707 kg/hm², respectively. The RFV of Pak Yin NO. 2 was higher than those of other varieties, reaching 113. The study indicates that the yield of oat variety Wild horse is higher than that of other varieties, and the RFV value of Pak Yin NO.2 is better. These two varieties are more suitable for planting in this area. [ABSTRACT FROM AUTHOR]

GaN films with an AlxGa1−xN/AlyGa1−yN superlattice (SL) buffer layer are grown on Si(111) substrates by metal-organic chemical vapor deposition (MOCVD). The structure and strain properties of the samples are studied by optical microscopy, Raman spectroscopy, x-ray diffractometry and atomic force microscopy. The results show that the strain status and crystalline quality of the GaN layers are strongly dependent on the difference of the Al composition between AlxGa1−xN barriers and AlyGa1−yN wells in the SLs. With a large Al composition difference, the GaN film tends to generate cracks on the surface due to the severe relaxation of the SLs. Otherwise, when using a small Al composition difference, the crystalline quality of the GaN layer degrades due to the poor function of the SLs in filtering dislocations. Under an optimized condition that the Al composition difference equals 0.1, the crack-free and compressive strained GaN film with an improved crystalline quality is achieved. Therefore, the AlxGa1−xN/AlyGa1−yN SL buffer layer is a promising buffer structure for growing thick GaN films on Si substrates without crack generation. [ABSTRACT FROM AUTHOR]

Objective: To determine risk factors associated with the prevalence of chronic obstructive pulmonary disease (COPD) in urban and rural populations in Chengdu., Methods: A multistage random cluster sampling method was adopted to select participants from four communities in Chengdu. All residents aged 40-70 yr. were eligible to participate in this study, which involved a questionnaire survey, physical examination and portable spirometry. Those with airflow limitations were also given post-bronchodilator testing 15 min after inhalation of a dose of 200 microg salbutamol. We defined a forced expiratory volume in one second/forced vital capacity (FEV1/FVC) of less than 70% as COPD. Logistic regression models were performed to identify risk factors of COPD., Results: Of a total of 1931 eligible participants, 1579 (81.77%) completed the questionnaire and spirometry. About 8.35% were identified with COPD: 7.69% in urban vs. 12.37% in rural (P<0.05). The prevalence of COPD increased with age (P<0.05) in the male and total populations. Rural COPD patients had a higher level of smoking rate and use of coal as fuel for cooking than their urban counterparts (P<0.05). But rural COPD patients had a lower level of BMI, waist circumference, literacy, and average household income per capita than their urban counterparts (P<0.05). The multivariate analysis showed that tobacco smoking index (pack-year), education, age and BMI were predictors of COPD for male patients; whereas, coal fuel usage, income and BMI were predictors of COPD for female patients., Conclusion: COPD prevalence is higher in rural areas than in urban Chengdu. Major risk factors of COPD include smoking, coal fuels and BMI.