Orbit constraint of a small bead on a rotating large circular hoop in a horizontal plane.

Orbit constraint problems can be encountered in mechanical equipment and amusement equipment. Mechanics exercises generally consider the ideal physical model, and the practical problems also consider the influence of friction, which makes the problem more complex and and practical. The problem of the force and oscillation of objects on orbit needs to be deeply discussed.

[Distribution and Pollution Assessment of Nutrients in the Surface Sediments of a Macrophyte-Dominated Zone in Lake Taihu].

To clarify the spatial distribution and pollution status of nutrients in the surface sediments from a macrophyte-dominated zone in Lake Taihu, total nitrogen (TN), total phosphorus (TP), alkali nitrogen (AN), available phosphorus (AP), and organic matter (OM) were measured at 60 sampling sites in Xukou Bay. A pollution evaluation and source apportionment analysis of these nutrients was also carried out. The average contents of TN, TP, AN, AP, and OM in the surface sediments of Xukou Bay were 1027.

Bad words prevail: Negatively charged Chinese characters accelerate attentional selection and preoccupy cognitive resources for consolidation.

Previous studies have produced contradictory findings regarding whether emotion exerts facilitative effects or inhibitory effects on perception. In the present study, we hypothesized that attention can be separated into the initial selection stage and the latter consolidation stage, and emotion plays a different role in each of these two stages. To test this hypothesis, we adopted the dual-stream rapid serial visual presentation paradigm (Goodbourn & Holcombe, Journal of Experimental Psychology: Human Perception and Performance, 41(2), 364-384, 2015), which provided separate measurements for selection latency (how delayed the attentional selection process is) and efficacy (how much information can be successfully consolidated for conscious report).

[Analysis of hydrogen bondings in polyurethane urea cured in graded temperature field by FTIR].

Hydrogen bondings in polyurethane urea elastomer, which reflect the microphase separation, have an important effect on the properties of the elastomer. The polyurethane urea elastomers, whose degree of microphase separation changed gradually, were prepared in the graded temperature field. Hydrogen bondings in them were investigated by FTIR technology.