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Based on the assumption that there is greater reciprocity of relationships (i.e., mutuality of give and take) in China than there is in the United States, the authors predicted cultural differences in the incidence of songs in which adult children express a desire to give back to parents. More songs expressing giving back to mothers than giving back to fathers was also predicted. Popular songs in both cultures were rated for themes of positive or negative giving back to parents. Almost all of the Chinese songs expressed positive giving back, and the majority of U.S. songs expressed negative giving back. More songs about mothers than about fathers were found only for the Chinese songs. American songs' focus on fathers, about whom there are negative feelings, may reflect the U.S. disposition to negative giving back. Processes underlying giving back-involving modeling, caregiving practices, direct tuition, and reciprocity-are discussed.

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The development of a new drilling fluid system with hydrate inhibition is of great significance for drilling safety in gas hydrate-bearing sediments. Considering the importance of the selection of a suitable thickener for drilling fluid systems under weak and strong driving forces, the hydrate inhibition of 0.1–0.5 wt% modified starch (MS), carboxymethylcellulose sodium (CMC), and xanthan gum (XG) aqueous solutions was studied. The applicability of these three thickeners were investigated through hydrate formation experiments, mesostructure observations, water activity tests, bubble retention observations, and rheological property tests. The results show that (1) under weak driving force, 0.3 wt% or higher concentration CMC and 0.3 wt% XG can almost completely inhibit hydrate formation due to the interactions between relatively small amounts of free water and CH4 molecules. Furthermore, the hydrate inhibition of higher XG concentrations was decreased due to their strong foam stability, leading to good contact between free water and CH4 molecules. Meanwhile, the hydrate inhibition of MS was weaker when compared with that of CMC and XG at the same concentrations. (2) Under strong driving force, the existence of the three 0.1–0.5 wt% thickeners could only slow down the hydrate formation rate, and hydrate inhibition due to XG was slightly better than that of the other two. This result implies that the effects of the different mesostructures on hydrate formation were severely weakened. Finally, (3) the tackifying effect of CMC was found to be stronger than that of XG and MS, and the rheological properties of the CMC solution were shown to be relatively weak compared to those of the XG and MS solutions; the CMC solution showed a more significant increase in viscosity with decreasing temperature, which is related to the differences in the mesostructures. Therefore, when the driving force of hydrate formation is relatively low, CMC is a good choice for the drilling fluid system when there is no requirement for cooling, while XG is more applicable for a system that needs cooling. In the case of a stronger driving force, XG is the optimal choice irrespective of whether the drilling fluid system needs cooling or not.

High-resolution polarimatric synthetic aperture radar (PolSAR) images can provide more detail information on land-cover types and increase the image complexity at the same time. Traditionally, pixel-based image classification that takes image pixel as a processing unit cannot make full use of various features contained in high-resolution remote sensing images, and thus may not obtain satisfactory results. Hence, object-based image classification (OBIC) methods using image objects as processing units have been introduced into the PolSAR image classification. However, current researches on OBIC methods for PolSAR images usually could not take advantage of multiscale information of image objects, leading to some results that are not as satisfactory as expected. In this article, a multilevel image description consisting of proposed pixel-level spatial and object-level semantic features is developed for OBIC of PolSAR images. At the image pixel level, based on th combination of polarimetric and morphological image descriptions, polarimetric morphological profiles are developed to describe pixel-level spatial features. At the image object level, based on the construction of object adjacent graph, an object-level semantic indicator is proposed, which takes into account the contextual neighborhood of image objects. Finally, the proposed pixel-level spatial and object-level semantic features are integrated and incorporated in an OBIC scheme for the PolSAR image classification. Two fully polarized datasets acquired by ESAR and uninhabited airborne vehicle synthetic aperture radar (UAVSAR), respectively, are adopted to evaluate the effectiveness of the proposed method. The experimental results validate that the comprehensive utilization of both pixel-level and object-level features can effectively improve the OBIC accuracy of PolSAR images.