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Mechanically interlocking structures that can enhance adhesion at the interface and regulate the stress distribution have been widely observed in biological systems. Inspired by the biological structures in the wings of beetles, we synthesized a holey graphene@SiO2 anode with strong mechanical interlocking, characterized it electrochemically, and explained its performance by finite element analysis and density functional calculations. The mechanically interlocking structure enhances lithium‐ion (Li+) storage by transmitting the strain from SiO2 to the holey graphene and by a mechano‐electrochemical coupling effect. The interlocking fit hinders the abscission of SiO2 and the distinctive structure reduces the stress and strain of SiO2 during (de)lithiation. The positive mechano‐electrochemical coupling effect preserves the amount of electrochemically active phase (LixSi) during cycles and facilitates Li+ diffusion. Therefore, the capacity shows only a slight attenuation after 8000 cycles (cycling stability), and the specific capacity is ~1200 mA h g−1 at 5 A/g (rate‐performance). This study furnishes a novel way to design high‐performance Li+/Na+/K+/Al3+ anodes with large volume expansion. Inspired by the biological structure in the wings of beetles, the holey graphene@SiO2 anode with strong mechanical interlocking is synthesized. The structure enhances lithium‐ion (Li+) storage by transmitting the strain from SiO2 to the holey graphene and by a mechano‐electrochemical coupling effect. The interlocking fit hinders the abscission of SiO2.

A single electron spin in a double quantum dot in a magnetic field is considered in terms of a four-level system. By describing the electron motion between the potential minima via spin-conserving tunneling and spin flip caused by a spin-orbit coupling, we inversely engineer faster-than-adiabatic state manipulation operations based on the geometry of four-dimensional rotations. In particular, we show how to transport a qubit among the quantum dots performing simultaneously required spin rotations.

Interactions between precipitation, vegetation, and erosion are crucial and not fully solved issues in the area of earth surface processes. The Qingshui River Basin (QRB), as the main sediment source tributary of the upper reaches of the Yellow River, is characterized by spatial heterogeneity of rainfall, vegetation, and soil erosion. In this study, we investigated the spatiotemporal variations of sediment yields within the QRB and further identified the coupling effects of precipitation and vegetation on soil erosion. We collected annual (1955 to 2016) and daily (2006 to 2016) hydrological and sediment series from six hydrological stations, which subdivided the whole basin into six different sub-basins with heterogeneity in climate and landscape. Variations in parameter a of the sediment rating curves among the six sub-basins continuously declined, showing the continuously increasing effect of vegetation coverage on reducing soil erosion. The unique combination of relationships between precipitation characteristics and vegetation patterns in six sub-basins and these coupling effects resulted in different precipitation–vegetation–erosion patterns in six sub-basins. Sediment yield followed bell-shaped relationships with vegetation and precipitation, with a clear critical threshold at normalized difference vegetation index (NDVI) = 0.36/precipitation = 100 mm at a monthly scale. Based on these thresholds, the non-linear relationships between precipitation, vegetation, and erosion were also explained. We also found that reducing the time lags in which vegetation follows precipitation may be effective in suppressing sediment yield. These findings could provide a quantitative approach to estimating the potential changes in sediment yield associated with proposed ecological rehabilitation schemes in this region.

The trade-offs between key functional traits in plants have a decisive impact on biomass production. However, how precipitation and nutrient deposition affect the trade-offs in traits and, ultimately, productivity is still unclear. In the present study, a mesocosm experiment was conducted to explore the relationships between biomass production and the aboveground and belowground key functional traits and their trade-offs under changes in precipitation and nutrient depositions in Leymus chinensis, a monodominant perennial rhizome grass widespread in the eastern Eurasian steppe. Our results showed that moisture is the key factor regulating the effect of nitrogen (N) and phosphorus (P) deposition on increased biomass production. Under conditions of average precipitation, water use efficiency (WUE) was the key trait determining the biomass of L. chinensis. There were obvious trade-offs between WUE and leaf area, specific leaf area, leaf thickness, and leaf dry matter. Conversely, under increasing precipitation, the effect of restricted soil water on leaf traits was relieved; the key limiting trait changed from WUE to plant height. These findings indicate that the shift of fundamental traits of photosynthetic carbon gain induced by precipitation under N and P deposition is the key ecological driving mechanism for the biomass production of typical dominant species in semi-arid grassland.

Background: Poor cerebral perfusion may contribute to cognitive impairment in type 2 diabetes mellitus (T2DM). We conducted a randomized controlled trial to test the hypothesis that resveratrol can enhance cerebral vasodilator function and thereby alleviate the cognitive deficits in T2DM. We have already reported that acute resveratrol consumption improved cerebrovascular responsiveness (CVR) to hypercapnia. We now report the effects of resveratrol on neurovascular coupling capacity (CVR to cognitive stimuli), cognitive performance and correlations with plasma resveratrol concentrations. Methods: Thirty-six T2DM adults aged 40–80 years were randomized to consume single doses of resveratrol (0, 75, 150 and 300 mg) at weekly intervals. Transcranial Doppler ultrasound was used to monitor changes in blood flow velocity (BFV) during a cognitive test battery. The battery consisted of dual-tasking (finger tapping with both Trail Making task and Serial Subtraction 3 task) and a computerized multi-tasking test that required attending to four tasks simultaneously. CVR to cognitive tasks was calculated as the per cent increase in BFV from pre-test basal to peak mean blood flow velocity and also as the area under the curve for BFV. Results: Compared to placebo, 75 mg resveratrol significantly improved neurovascular coupling capacity, which correlated with plasma total resveratrol levels. Enhanced performance on the multi-tasking test battery was also evident following 75 mg and 300 mg of resveratrol. Conclusion: a single 75 mg dose of resveratrol was able to improve neurovascular coupling and cognitive performance in T2DM. Evaluation of benefits of chronic resveratrol supplementation is now warranted.

Heating, Ventilating, and Air Conditioning (HVAC) systems are the major energy-consuming devices in buildings. Nowadays, due to the high demand for HVAC system installation in buildings, designing an effective controller in order to decrease the energy consumption of the devices while meeting the thermal comfort demands in buildings are the most important goals of control designers. The purpose of this article is to investigate the different control methods for Heating, Ventilating, and Air Conditioning and Refrigeration (HVAC & R) systems. The advantages and disadvantages of each control method are discussed and finally the Fuzzy Cognitive Map (FCM) method is introduced as a new strategy for HVAC systems. The FCM method is an intelligent and advanced control technique to address the nonlinearity, Multiple-Input and Multiple-Output (MIMO), complexity and coupling effect features of the systems. The significance of this method and improvements by this method are compared with other methods.

The nonlinear thermo-mechanic coupling effect refers to the interaction between the nonlinear dynamic characteristics of a dual-rotor system and the thermal effect of an intershaft bearing. In this paper, the nonlinear thermo-mechanic coupling effect of the dual-rotor system is proposed and studied by the operating radial clearance and dynamic load of the intershaft bearing. A nonlinear dynamic model of the dual-rotor system under the thermal effect of the intershaft bearing is established by considering nonlinear factors such as the Hertzian contact force and the operating radial clearance of the intershaft bearing. The dynamic load of the intershaft bearing is obtained based on the dynamic responses of the system. Based on this, a thermal effect model of the intershaft bearing considering the nonlinear dynamic characteristics of the system is proposed. The operating radial clearance of the intershaft bearing is attained according to the temperature field of the intershaft bearing. The thermo-mechanic coupling model of the dual-rotor system is presented by connecting the dynamic model and the thermal effect model. The results solved by numerical iteration show that the nonlinear dynamic characteristics of the dual-rotor system are deeply coupled with the thermal effect of the intershaft bearing, and become weaker. In turn, a complex nonlinear thermal effect affects the bearing due to the nonlinear dynamic characteristics of the system. Furthermore, the operating radial clearance of the intershaft bearing is closely related to the thermo-mechanic coupling effect of the system. The operating radial clearance decreases with increasing temperature, decreases with decreasing initial radial clearance, and decreases sharply in the resonance regions. Thus, the “negative clearance” may affect the operating radial clearance of the intershaft bearing, which endangers the operation of the rotor system. Moreover, the nonlinear characteristics of the thermo-mechanic coupling effect become stronger as the ambient temperature increases. The results presented in this paper provide insight into the mechanism of the nonlinear thermo-mechanic coupling effect and new theoretical guidances for the dynamic and thermodynamic design of the intershaft bearing in the dual-rotor system.

Deformation and failure of rock have size and strain rate effects. However, the coupling effect of sample size and strain rate on strength of rock is not well studied. At present, the experimental research in this area has accumulated definite experimental data, but there is a lack of theoretical model with solid theoretical basis. Therefore, in the present paper the coupling effect of sample size and strain rate on compressive strength of rock is studied theoretically. In the quasi-static loading regime, the formula for the coupling effect of sample size and strain rate on rock strength is obtained by combining the thermally activated mechanism and the static size effect law of rock strength. In the dynamic loading regime, the formula for the coupling effect of sample size and strain rate on the rock compressive strength is determined by using the Weibull’s activation law of rock defects and the shortest time condition of propagation and coalescence of cracks at different scale levels. Based on the conclusion that the strain rate sensitivity of the strength of rock is the result of competition between the coexisting thermally activated and macro-viscous mechanisms, which dominate at different ranges of strain rates, the formulae for the coupling effect of sample size and strain rate in static and dynamic regimes are superposed to obtain an unified formula for the coupling effect of strain rate and sample size effect on rock compressive strength. The critical strain rate for given sample size and the critical sample size for given strain rate are determined. The comparison with the existing theoretical models and experimental results shows that the present theoretical model is consistent with the existing theories and experimental results, indicating that the proposed model is reasonable. The present model is applicable to rocks of laboratory scale levels.HighlightsThe formulae for the coupling effect of sample size and strain rate on rock strength in the quasi-static and dynamic loading regimes are obtained.The unified formula for the coupling effect of strain rate and sample size effect on rock strength is obtained.The critical strain rate for given sample size and the critical sample size for given strain rate are determined.The present model is applicable for rocks.

Industrial green and low-carbon transformation plays a crucial role in China’s efforts to achieve its Carbon peaking and Carbon neutrality objectives. The implementation of environmental regulation policies is a key institutional framework that facilitates this transformation. Therefore, it is of great importance to explore the impact and interplay of these policies on industrial green and low-carbon transformation to foster high-quality economic development. This study categorizes environmental regulation policy instruments into three types: command-type, investment-type, and expense-type. Using industrial panel data from 30 provinces in China spanning the period from 1997 to 2021, both theoretical analysis and empirical testing are conducted to investigate the effects of these different policy instruments on industrial green and low-carbon transformation. The benchmark regression results show that the impact of command-type environmental regulation and investment-type environmental regulation on industrial green and low-carbon transformation shows an inverted U-shaped feature of rising first and then declining. The impact of cost-based environmental regulation on industrial green and low-carbon transformation shows a U-shaped feature of decreasing first and then increasing. The coupling of command-type environmental regulation and investment-type environmental regulation, command-type environmental regulation and expense-type environmental regulation, and the coupling of the three kinds of environmental regulation can promote industrial green and low-carbon transformation. The mechanism test results show that the impact of formal environmental regulation on industrial green and low-carbon transformation has a transmission mode of “formal environmental regulation–green technology innovation path–green and low-carbon transformation.”

Electronic skin (e‐skin), new generation of flexible wearable electronic devices, has characteristics including flexibility, thinness, biocompatibility with broad application prospects, and a crucial place in future wearable electronics. With the increasing demand for wearable sensor systems, the realization of multifunctional e‐skin with low power consumption or even autonomous energy is urgently needed. The latest progress of multifunctional self‐powered e‐skin for applications in physiological health, human–machine interaction (HMI), virtual reality (VR), and artificial intelligence (AI) is presented here. Various energy conversion effects for the driving energy problem of multifunctional e‐skin are summarized. An overview of various types of self‐powered e‐skins, including single‐effect e‐skins and multifunctional coupling‐effects e‐skin systems is provided, where the aspects of material preparation, device assembly, and output signal analysis of the self‐powered multifunctional e‐skin are described. In the end, the existing problems and prospects in this field are also discussed. In this review, we compile the latest work of self‐powered multifunction e‐skin, discussing related energy sources and coupling techniques. In addition, the latest progress of multifunctional self‐powered e‐skin for applications in physiological health, human–machine interaction (HMI), virtual reality (VR), and artificial intelligence (AI) are also present.