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Splines are widely used in aeronautic applications; however, misaligned splines often suffer contact stress concentration and fretting wear fatigue failure. Crowned modification is a useful way to relieve contact stress concentration and mitigate fretting wear for misaligned splines, but it is unclear how this method works. In this study, contact stresses for involute splines are calculated using finite elements and correlated to first-hand experimental results on fretting wear obtained using a dedicated test rig. Both contact stress distribution prediction and fretting wear measurement indicate that the crowned magnitude of splines should be selected according to the operating angular misalignment. ● A dedicated test rig for spline fretting wear is constructed. ● First-hand experimental results on spline fretting wear are presented. ● Spline contact stress predictions are implemented using finite elements. ● Optimum crowned magnitude depends on operating angular misalignment.A positive correlation exists between spline fretting wear and contact stress. [ABSTRACT FROM AUTHOR]

• A dynamic model for PGS with journal bearing and flexible structure is established. • Impact of differences of journal bearing on load sharing characteristics is studied. • Effect of flexible ring gear and pin on load sharing performance are compared. • Influence of installation form of bearing with error on load sharing is explored. Owing to its advantages of a small size, excellent vibration resistance, and smooth operation, journal bearing is widely used in planetary gear systems (PGSs). When there are errors in the journal bearing, the load sharing performance (LSP) of the system is significantly affected. A dynamic model is established to study the influence of journal bearing with errors on the load sharing characteristics of the PGS. The dynamic characteristics of the journal bearing and the flexibility of the ring gear and pin are also considered. The characteristics of the journal bearing and influence of the working conditions and flexible structure on the load sharing characteristic are analyzed. The installation forms of the bearing with different clearance ratios are classified, and the load sharing characteristics of the system under different installation forms are explored. The results indicate that load sharing characteristics are related to the parameters of the journal bearing. Compared with the flexibility of the ring gear, the pin has a limited impact on the load sharing characteristics of the system. The LSP of the adjacent installation mode of a journal bearing with errors is better than that of the interval installation mode. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Peden et al. have revealed a significant association between four new risk loci and coronary heart disease (CHD) in Europeans and South Asians. The goal of this study is to evaluate the contribution of these genetic loci to CHD risk in Han Chinese. Methods: We recruited 161 CHD patients and 112 controls proved by angiography originated from Ningbo in the Eastern China, and performed a case-control association study of the four significant SNPs. Results: Among the four tested SNPs, we found a significant association of rs974819 in PDGFD gene with CHD (allele p=0.04; OR=1.45, 95% CI=1.02 - 2.08) and the allele A/G of rs974819 shows significant difference in females (allele p=0.04; OR=1.83, 95% CI=1.01 - 3.31). A further meta-analysis showed that rs974819 of PDGFD gene was significantly associated with an increasing risk of CHD (OR=1.08, 95% CI=1.05 - 1.11) in both Europeans and South Asians including Han Chinese. Conclusions: Our findings suggests that rs974819 of PDGFD is also a CHD risk factor in Han Chinese. In addition, it presents a sex-dependent genetic effect. [Copyright &y& Elsevier]

Two novel halogen-free liquids additives [DHB][BScB] and [MA-BIm][BScB] are synthesized and their tribological performance in 500 N base oil are evaluated using 4-ball machine for the first time. The results show that [DHB][BScB] and [MA-BIm][BScB] can decrease the friction coefficient of 500 N base oil by 42.7% and 42.1% at 2.5 wt% concentration respectively and they both possess excellent corrosion resistance. According to the analysis results of X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), [DHB][BScB] and [MA-BIm][BScB] can form chemical films consisting of iron oxide and B 2 O 3 on the worn steel surface. In addition, a lubrication mechanism is speculated and there may be a competitive adsorption between anion and cation. [Display omitted] • Two kinds of novel halogen-free and environmentally friendly borate ionic liquids are synthesized. • Two borate ionic liquids can effectively enhance the tribological properties of 500 N base oil. • The thermal stabilities of two ionic liquids are evaluated and they both possess higher decomposed temperature. • Two kinds of environmentally friendly ionic liquids exhibit excellent anti-corrosion properties. • A lubrication mechanism is speculated that there may be a competitive adsorption between anion and cation. [ABSTRACT FROM AUTHOR]

More than 70% of global rice production depends on irrigation water, which has brought on a progressive reduction in the groundwater table. Further groundwater withdrawal are unsustainable for future rice production. Sustainable rice production calls for the use of resource-saving and environmentally friendly rice varieties. This study investigated the morphological and physiological mechanisms of biomass and tissue phosphorus accumulation in a water-saving and drought-resistance rice variety (Hanyou73) and a normal paddy rice variety (Hyou518) under different water management regimes. The two rice cultivars were grown in pot experiments carried out with factorial combinations of three water regimes, conventional irrigation (high irrigation rate, HR), 60% of conventional irrigation (medium irrigation rate, MR), and 20% of conventional irrigation (low irrigation rate, LR) for four-years. While the grain yield of Hanyou73 was similar as Hyou518 under HR, it was significantly higher than Hyou518 under MR and LR. Under deficit irrigation, the tissue-specific biomass of Hanyou73 was higher than that of Hyou518, and the total P accumulation of Hanyou73 was 70% greater than that of Hyou518. Meanwhile, the root growth, root oxidation activity, and absorption area of Hanyou73 under the MR and LR treatments were significantly higher than those of Hyou518. Analysis of root exudate metabolites revealed an abundance of organic acids produced by the Hanyou73 roots under, which may account for its higher P uptake. Overall, the findings of this study indicate that Hanyou73 promoted P uptake to maintain higher yields under deficit irrigation. The higher P uptake by Hanyou73 may be related to its altered root physiology, which may be the mechanism by which Hanyou73 adapts to water saving irrigation conditions and maintains its yield traits. • Sustainable rice production requires the cultivation of Water-saving and drought-resistance rice varieties. • Hanyou73" maintained high yield and phosphorus levels under low-irrigation condition. • Higher phosphorus uptake supported "Hanyou73" yield. • The physiological mechanism underlying the high phosphorus uptake is an increase in root oxidation and absorption area. • The root exudates of "Hanyou73" contained high levels of organic acids and anions. [ABSTRACT FROM AUTHOR]