Recovery in soil carbon stocks but reduced carbon stabilization after near-natural restoration in degraded alpine meadows.

Near-natural restoration is acknowledged as an effective strategy for enhancing soil organic carbon (SOC) sequestration in degraded grasslands. However, the alterations in SOC fractions, stability, and relative sequestration capacity after restoration of degraded alpine meadows remain uncertain. In this study, we utilized the degraded alpine meadows on the northeastern edge of the Tibetan Plateau as a research area, with grazing as the control (CK) and restoration of 20 years of banned grazing (BG) and growing season resting grazing (RG).

Universal quantum Otto heat machine based on the Dicke model.

In this paper we study a quantum Otto thermal machine where the working substance is composed of N identical qubits coupled to a single mode of a bosonic field, where the atoms and the field interact with a reservoir, as described by the so-called open Dicke model. By controlling the relevant and experimentally accessible parameters of the model we show that it is possible to build a universal quantum heat machine (UQHM) that can function as an engine, refrigerator, heater, or accelerator. The heat and work exchanges are computed taking into account the growth of the number N of atoms as well as the coupling regimes characteristic of the Dicke model for several ratios of temperatures of the two thermal reservoirs.

Response of soil stoichiometric characteristics to climatic factors in temperate steppe of Longzhong region, China.

We explored the relationship between climate factors (mean annual precipitation and mean annual temperature) and the contents and stoichiometry of soil carbon (C), nitrogen (N), and phosphorus (P) at different soil depths (0-5, 5-10, 10-20, 20-30, 30-50, 50-70, and 70-100 cm) temperate steppe of Longzhong. The results showed with the increases of soil depth, soil C, N contents, C:P, and N:P gradually decreased from 21.88 g·kg, 1.