The Energy Efficiency Rebound Effect in China from Three Industries Perspective

AbstractBased on the panel data of three industries in China, this paper calculates the energy rebound effect arising from energy efficiency improvement, by stripping the rebound of energy usage caused by industrial restructuring from model. Results indicate: the similarity between them demonstrating energy efficiency rebound effect as the main component of energy rebound effect; the delayed rebound peak of the secondary industry reflects its lagged respond to changes in energy efficiency; with regard to the peak value in 2009 when calculating the whole nation, author concerns it with the intensification in investment on basic industries and relaxation of restriction over high energy consumption enterprises; the relatively larger value of energy efficiency rebound in China can not be ignored by policy-maker

Revealing microbial processes and nutrient limitation in soil through ecoenzymatic stoichiometry and glomalin-related soil proteins in a retreating glacier forefield

The glacial retreat is observed and predicted to increase in intensity especially in high-elevation areas as a result of global warming, which leaves behind a primary succession along soil chronosequences. Although soil microbes have been recognized as main drivers of ecological and evolutionary processes, our understanding of their effects on nutrient biogeochemistry during primary succession remains limited. In this study, we investigated changes in the microbial community structure, ecoenzymatic stoichiometry, and glomalin-related soil protein (GRSP) accumulation in the Hailuogou Glacier Chronosequence, located on the eastern Tibetan Plateau. We wanted to reveal the effects of nutrient limitation on soil microbes and the relative contributions of edaphic and biotic factors. The results showed that with an increasing soil age, there was a steady increase in the microbial biomass and a shift from a bacterial to fungal dominated pattern. Soil enzyme stoichiometry and analyses on threshold elemental ratios revealed that microbial activities are limited by carbon and nitrogen during the early successional stage (3-52 years), while phosphorus was the main limiting factor during later stages (80-120 years). Moreover, the redundancy analysis and structural equation modeling suggested that during early stages edaphic factors had a greater impact on microbial processes, while the vegetation factors were most influential during the last two stages. Overall, these results highlighted the importance of integrating knowledge of the microbial community structure, soil enzyme activities and GRSP to gain a holistic view of soil-plant microbe interactions during ecosystem successions.Peer reviewe

Distinct co-occurrence patterns and driving forces of rare and abundant bacterial subcommunities following a glacial retreat in the eastern Tibetan Plateau

Unraveling the dynamics and driving forces of abundant and rare bacteria in response to glacial retreat is essential for a deep understanding of their ecological and evolutionary processes. Here, we used Illumina sequencing datasets to investigate ecological abundance, successional dynamics, and the co-occurrence patterns of abundant and rare bacteria associated with different stages of soil development in the Hailuogou Glacier Chronosequence. Abundant taxa exhibited ubiquitous distribution and tight clustering, while rare taxa showed uneven distribution and loose clustering along the successional stages. Both abundant and rare subcommunities were driven by different factors during assembly: the interactions of biotic and edaphic factors were the main driving forces, although less important for rare taxa than for the abundant ones. In particular, the redundancy analysis and structural equation modeling showed that soil organic C, pH, and plant richness primarily affected abundant subcommunities, while soil N and pH were most influential for rare subcommunities. More importantly, variation partitioning showed that edaphic factors exhibited a slightly greater influence on both abundant (7.8%) and rare (4.5%) subcommunities compared to biotic factors. Both abundant and rare bacteria exhibited a more compact network topology at the middle than at the other chronosequence stages. The overlapping nodes mainly belonged to Proteobacteria and Acidobacteria in abundant taxa and Planctomycetia, Sphingobacteriia, and Phycisphaerae in rare taxa. In addition, the network analysis showed that the abundant taxa exhibited closer relationships and more influence on other co-occurrences in the community when compared to rare taxa. These findings collectively reveal divergent co-occurrence patterns and driving forces for abundant and rare subcommunities along a glacier forefield chronosequence in the eastern Tibetan Plateau.Peer reviewe

Decoupled and Analytical Model of the Quad-Active-Bridge DC/DC Wind Converter under Transmitting Instantaneous Pulsating Power

The quad-active-bridge (QAB) DC/DC converter has shown superior advantages in eliminating the low-frequency voltage ripple in the cascaded wind power converter. However, the power flowing into the QAB converter contain low-frequency pulsation, causing low-frequency envelope oscillation issues inside the QAB converter. This paper proposes a decoupled and analytical model for quantitively analysis of the corresponding operation characteristics. Specifically, a summation difference transformation is proposed to decouple the multivariable coupling model as a diagonal decoupled model. The QAB converter voltages with time-varying angles are decomposed as the supervision of multiple frequency components by the Bessel function. Various characteristics such as input current stress (peak and rms), low-frequency envelope oscillations have been thoroughly analyzed under instantaneous pulsating power transmission with the proposed model. These results can be further used for designing more high-performance control strategies to optimize operation. Simulation and experimental results are presented to validate the proposed analytical model

Decoupled and Analytical Model of the Quad-Active-Bridge DC/DC Wind Converter under Transmitting Instantaneous Pulsating Power

The quad-active-bridge (QAB) DC/DC converter has shown superior advantages in eliminating the low-frequency voltage ripple in the cascaded wind power converter. However, the power flowing into the QAB converter contain low-frequency pulsation, causing low-frequency envelope oscillation issues inside the QAB converter. This paper proposes a decoupled and analytical model for quantitively analysis of the corresponding operation characteristics. Specifically, a summation difference transformation is proposed to decouple the multivariable coupling model as a diagonal decoupled model. The QAB converter voltages with time-varying angles are decomposed as the supervision of multiple frequency components by the Bessel function. Various characteristics such as input current stress (peak and rms), low-frequency envelope oscillations have been thoroughly analyzed under instantaneous pulsating power transmission with the proposed model. These results can be further used for designing more high-performance control strategies to optimize operation. Simulation and experimental results are presented to validate the proposed analytical model

Flexural behaviour of damaged concrete T-beams reinforced with ultra-high performance concrete filling

To improve the flexural performance of damaged reinforced concrete T-beams, a method of filling ultra-high performance concrete (UHPC) in the damaged area was adopted. Experimental studies were conducted on two UHPC-reinforced concrete T-beams with different lengths of damaged areas and one undamaged concrete T-beam as a reference. Crack distribution, failure modes, cracking loads, flexural capacities, and strain variation of the specimens were analyzed. Subsequently, a nonlinear finite element (FE) model of the UHPC-reinforced T-beam was developed using ABAQUS, and the FE model results were compared with the experimental results to validate the accuracy of the FE simulation method. The results indicated that the two UHPC-reinforced T-beams exhibited a similar flexural failure process to the undamaged T-beam. The longitudinal tensile strain distribution at the mid-span section showed that the composite section formed by the filling of UHPC in the damaged region still adhered the assumption of the planar section. Owing to the excellent bond performance between UHPC and the existing concrete, the main cracks of the UHPC-reinforced T-beams appeared in the chiseled area, and the crack widths of the UHPC-reinforced T-beams under the same load were smaller than those of the reference T-beam. Overall, the reinforcing method of filling UHPC in the damaged region can restore or even enhance the flexural performance of the damaged reinforced concrete T-beams

Divergent assemblage patterns and driving forces for bacterial and fungal communities along a glacier forefield chronosequence

Despite the ubiquitous distributions and critical ecological functions of microorganisms in pedogenesis and ecosystem development in recently deglaciated areas, there are contrasting successional trajectories among bacteria and fungi, but the driving forces of community assembly still remain poorly resolved. In this study, we analyzed both bacterial and fungal lineages associated with seven different stages in the Hailuogou Glacier Chronosequence, to quantify their taxonomic composition and successional dynamics, and to decipher the relative contribution from the bottom-up control of soil nutrients and altered vegetation as well as top-down pressures from nematode grazers. Co-occurrence networks showed that the community complexity for both bacteria and fungi typically peaked at the middle chronosequence stages. The overlapping nodes mainly belonged to Proteobacteria and Acidobacteria in bacteria, and Ascomycota and Basidiomycota in fungi, which was further supported by the indicator species analysis. Variation in partitioning and structural equation modeling suggested that edaphic properties were the primary agents shaping microbial community structures, especially at the early stages. The importance of biotic factors, including plant richness and nematode feeding, increased during the last two stages along with the establishment of a coniferous forest, eventually governing the turnover of fungal communities. Moreover, bacterial communities exhibited a more compact network topology during assembly, thus supporting determinism, whereas the looser clustering of fungal communities illustrated that they were determined more by stochastic processes. These pieces of evidence collectively reveal divergent successional trajectories and driving forces for soil bacterial and fungal communities along a glacier forefield chronosequence.Peer reviewe

A Contactless Health Monitoring System for Vital Signs Monitoring, Human Activity Recognition and Tracking

Integrated sensing and communication technologies provide essential sensing capabilities that address pressing challenges in remote health monitoring systems. However, most of today’s systems remain obtrusive, requiring users to wear devices, interfering with people’s daily activities, and often raising privacy concerns. Herein, we present HealthDAR, a low-cost, contactless, and easy-to-deploy health monitoring system. Specifically, HealthDAR encompasses three interventions: i) Symptom Early Detection (monitoring of vital signs and cough detection), ii) Tracking & Social Distancing, and iii) Preventive Measures (monitoring of daily activities such as face-touching and hand-washing). HealthDAR has three key components: (1) A low-cost, low-energy, and compact integrated radar system, (2) A simultaneous signal processing combined deep learning (SSPDL) network for cough detection, and (3) A deep learning method for the classification of daily activities. Through performance tests involving multiple subjects across uncontrolled environments, we demonstrate HealthDAR’s practical utility for health monitoring