•Comprehensive review of energy harvesting in roadway and bridges.•Summarized previous work on material and system using experiments and modeling.•Compare levelized cost of energy, TRL, advantages, ...disadvantages, and support.
Energy harvesting is a promising technique that can help produce renewable and clean energy and improve sustainability of infrastructure. The objective of this paper is to review available energy harvesting techniques that are used for roadway and bridge for different applications, including photovoltaic cell, solar collector, geothermal, thermoelectric, electromagnetic, and piezoelectric systems. The energy harvested can produce electric energy, provide heating or cooling, ice melting, power wireless sensors, and monitor structure conditions. Each energy harvesting technology is examined in depth including working principles, application examples, prototype developments, and major findings reported in the literature. The review summarized previous study efforts on energy harvesting system in the areas of material design, system optimization, theoretical analysis, laboratory testing, field experiment, and numerical modeling. Different energy-harvesting technologies were compared in terms of power output, cost-effectiveness, technology readiness level, advantages and disadvantages, support from government and industry. Finally, future research recommendations of energy harvesting in roadway and bridge were proposed.
Heavy Meiyu‐Baiu rainfall occurred over central‐east China and Japan in June–July 2020. This study analyzes observational and reanalysis data and performs atmospheric model simulations to investigate ...its causes. It is found that low Arctic sea ice cover (SIC) in late spring‐early summer of 2020 along the Siberian coast was an important factor. The low SIC caused local warming and high pressure, resulted in excessive atmospheric blockings over East Siberia, which caused cold air outbreaks into the Meiyu‐Baiu region, stopped the seasonal northward march of the Meiyu‐Baiu front, and increased the thermal contrast across the front, leading to record‐breaking rainfall in June–July 2020. Our results suggest that the 2020 extreme Meiyu‐Baiu was partly caused by the low SIC around the Siberian coast through its impact on East Siberian blockings. As sea ice along the Siberian coast decreases under global warming, its variations and thus influence on Meiyu‐Baiu rainfall may weaken.
Plain Language Summary
Meiyu‐Baiu, a west—east oriented stationary front from central‐east China to Japan, usually persists from mid‐June to mid‐July. In June–July 2020, central‐east China and Japan encountered record‐breaking Meiyu‐Baiu rainfall. Through analyses of observational and reanalysis data, we found that excessive East Siberian atmospheric blockings—large‐scale quasi‐stationary anticyclonic circulations—during the 2020 Meiyu‐Baiu season increased cold air outbreaks into the Meiyu‐Baiu region, stopped the northward march of the Meiyu‐Baiu front, and enhanced the temperature contrast across the front, leading to record‐breaking Meiyu‐Baiu rainfall in 2020. Using atmospheric model experiments, we further show that the frequent East Siberian blockings can be largely attributed to excessive sea ice melting and the concurring warming along the Siberian coast. The lower‐atmospheric warming reduced local meridional temperature gradients and zonal winds, which favors East Siberian blockings. Our results highlight the effect of Arctic sea ice decline and the associated warming on Meiyu‐Baiu rainfall and provide a new mechanism for the Arctic to affect mid‐latitude precipitation in late spring‐early summer. This Arctic effect may change in the future as late spring‐early summer sea ice diminishes under global warming.
Key Points
The excessive atmospheric blockings over East Siberia enhanced the Meiyu‐Baiu rainfall in June–July 2020
The low Arctic sea ice favored East Siberian blockings and greatly intensified the Meiyu‐Baiu rain belt, especially in July 2020
The influence of Greenland blocking on continental cold anomalies in the Northern Hemisphere is examined. It is found that westward moving Greenland blocking (WGB) events in the recent decade are ...more strongly related to the sea ice decline over the Baffin Bay, Davis Strait, and Labrador Sea (BDL), while the quasi‐stationary Greenland blocking (QGB) events are more strongly related to the negative phase of the North Atlantic Oscillation. The frequency of WGB events is significantly increased owing to reduced mid‐high‐latitude westerly winds in the North Atlantic and its upstream region because of intensified Arctic warming related to the large BDL sea ice decline. It is further revealed that North American low temperatures are more sensitive to the WGB, while European low temperatures are more sensitive to the QGB. For the WGB, an intense cold anomaly is seen over the eastern North America. But for the QGB, strong cold anomalies appear over the North Europe and eastern Asia. Thus, it is concluded that more winter cold air outbreaks should occur over the eastern North America, if large BDL sea ice decline continues in the recent decade.
Key Points
The role of the Arctic sea ice decline in North American cold winters
The physical mechamism of Arctic sea ice decline affecting cold winters over the North America
The linkage between the North American cold winters and the retrogression of Greenland blocking
•The differences of AOs obtained by chemical and enzymatic degradation.•The summary of separation, purification methods, and structure of AOs.•The summary of series of biological activities of AOs ...like antioxidant, etc.•Correlation between biological activities of AOs with Mw, DP and sulfate group.
Agar, a gelatinous polysaccharide which is in the cell wall of many red algae, is widely used as food and gelling agent. Agar oligosaccharides (AOs), the hydrolysate of agar, show much more kinds of bio-activities because of its lower molecular weight, better water solubility and higher absorption efficiency. It is indicated that AOs with different structure and degree of polymerization, i.e. series of agaro-oligosaccharides and neoagaro-oligosaccharides, can be obtained under different preparation conditions. In addition, the biological activities of AOs are diversely and closely correlated to the composition and structure. This review aims to comprehensively summarize the preparation, structural characteristics and bio-activities of AOs, so as to provide a reference for applications of AOs as marine natural products in pharmacological, cosmetics and nutraceutical fields.
A winter Eurasian cooling trend and a large decline of winter sea ice concentration (SIC) in the Barents–Kara Seas (BKS) are striking features of recent climate changes. The question arises as to ...what extent these phenomena are related. A mechanism is presented that establishes a link between recent winter SIC decline and midlatitude cold extremes. Such potential weather linkages are mediated by whether there is a weak north–south gradient of background tropospheric potential vorticity (PV). A strong background PV gradient, which usually occurs in North Atlantic and Pacific Ocean midlatitudes, acts as a barrier that inhibits atmospheric blocking and southward cold air intrusion. Conversely, atmospheric blocking is more persistent in weakened PV gradient regions over Eurasia, Greenland, and northwestern North America because of weakened energy dispersion and intensified nonlinearity. The small climatological PV gradients over mid- to high-latitude Eurasia have become weaker in recent decades as BKS air temperatures show positive trends due to SIC loss, and this has led to more persistent high-latitude Ural-region blocking. These factors contribute to increased cold winter trend in East Asia. It is found, however, that in years when the winter PV gradient is small the East Asian cold extremes can even occur in the absence of large negative SIC anomalies. Thus, the magnitude of background PV gradient is an important controller of Arctic–midlatitude weather linkages, but it plays no role if Ural blocking is not present. Thus, the “PV barrier” concept presents a critical insight into the mechanism producing cold Eurasian extremes and is hypothesized to set up such Arctic–midlatitude linkages in other locations.
Abstract
Despite extratropical forcing being recognized as an important factor that can modulate El Niño-Southern oscillation (ENSO) properties on the interannual time scale, little is known about ...whether and how Arctic forcing changes the tropical sea surface temperature (SST). This current study reveals a significant link between the net surface sensible heat flux (SHF) in the Arctic and the SST anomalies in the tropical eastern Pacific (TEP). Specifically, anomalous upward SHF into the Arctic atmosphere in February leads to a warmer TEP in the subsequent spring and summer. A northeast-southwest-tilted North Pacific Oscillation-like atmospheric pattern associated with the upward Arctic SHF anomaly induces SST cooling in the subtropical North Pacific via positive Wind-Evaporation-SST feedback, which further promotes TEP SST warming via meridional heat advection, thermocline feedback, and nonlinear processes. The spring-to-summer TEP SST anomalies driven by the preceding anomalous Arctic SHF can potentially modulate the seasonal evolution of ENSO. Our findings imply that we should take into account the Arctic-tropics linkages when comprehensively understanding the ENSO variability and improving ENSO projection skills.
Coordination-driven surface modification is an effective strategy to achieve nanosystem functionalization and improved physicochemical performance. Black phosphorus (BP)-based nanomaterials ...demonstrate great potential in cancer therapy, but their poor stability, low X-ray mass attenuation coefficient, and nonselectivity limit the application in radiotherapy. Herein, we used unsaturated iridium complex to coordinate with BP nanosheets to synthesize a two-dimensional layered nanosystem (RGD-Ir@BP) with higher biostability. Ir complex improves the photoelectric properties and photoinduced charge carrier dynamics of BP, hence Ir@BP generated more singlet oxygen after X-ray irradiation. In
experiments, with X-ray irradiation, RGD-Ir@BP effectively inhibited nasopharyngeal carcinoma tumor growth but with minor side effects. Additionally, based on untargeted metabolomics analysis, the combined treatment specifically down-regulated the tumor proliferative mark of prostaglandin E2 in cancer cells. In general, this study provides a design strategy of high-performance coordination-driven BP-based nanosensitizer in cancer radiotherapy.
Arctic warming has significant environmental and social impacts. Arctic long‐term warming trend is modulated by decadal‐to‐multidecadal variations. Improved understanding of how different external ...forcings and internal variability affect Arctic surface air temperature (SAT) is crucial for explaining and predicting Arctic climate changes. We analyze multiple observational data sets and large ensembles of climate model simulations to quantify the contributions of specific external forcings and various modes of internal variability to Arctic SAT changes during 1900–2021. We find that the long‐term trend and total variance in Arctic‐mean SAT since 1900 are largely forced responses, including warming due to greenhouse gases and natural forcings and cooling due to anthropogenic aerosols. In contrast, internal variability dominates the early 20th century Arctic warming and mid‐20th century Arctic cooling. Internal variability also explains ∼40% of the recent Arctic warming from 1979 to 2021. Unforced changes in Arctic SAT are largely attributed to two leading modes. The first is pan‐Arctic warming with stronger loading over the Eurasian sector, accounting for 70% of the unforced variance and closely related to the positive phase of the unforced Atlantic Multidecadal Oscillation (AMO). The second mode exhibits relatively weak warming averaged over the entire Arctic with warming over the North American‐Pacific sector and cooling over the Atlantic sector, explaining 10% of the unforced variance and likely caused by the positive phase of the unforced Interdecadal Pacific Oscillation (IPO). The AMO‐related changes dominate the unforced Arctic warming since 1979, while the IPO‐related changes contribute to the decadal SAT changes over the North American‐Pacific Arctic.
Plain Language Summary
The Arctic warms much faster than the rest of the world, leading to significant local and remote influences. Warming in the Arctic is not uniform over time, with decadal‐to‐multidecadal variations upon the long‐term trend. The changes in Arctic surface air temperature (SAT) can be attributed to either instrinct variability within the climate system or external forcings including anthropogenic factors such as greenhouse gases emission and natural factors such as volcanic eruptions. Understanding of the relative contributions of internal variability and external forcing to observed changes in Arctic SAT is crucial for improving Arctic climate projections in coming decades. By synthesizing multiple observational data sets and large‐ensemble climate simulations, we find that the Arctic experienced long‐term warming with some periods of slowdown in response to external forcing, which largely explains the overall change since 1900. Internal variability, particularly the multidecadal oscillation in the North Atlantic, dominates the early 20th century warming and mid‐20th century cooling and significantly contributes to the recent rapid warming since 1979. A regression‐based rescaling method removes systematic biases in model‐simulated response (in comparison with observations), ensuring that our results are not influenced by the choice of climate models, as long as they are under the same historical forcing.
Key Points
Externally forced Arctic warming dominates the trend and variance in Arctic surface air temperature during 1900–2021
Most of the internally generated Arctic temperature changes are related to the unforced Atlantic Multidecadal Oscillation
Internal variability explains 40% of the Arctic warming from 1979 to 2021, while greenhouse gases and natural forcings account for the rest
The sea‐ice extent (SIE) in the Weddell Sea plays a crucial role in the Antarctic climate system. Many studies have examined its long‐term trend, however whether its year‐to‐year variation has ...changed remains unclear. We found an amplified year‐to‐year variance of the Weddell Sea SIE in austral summer since 1998/1999 in observational datasets. Analyses of sea‐ice concentration budget and surface fluxes indicate that it is the thermodynamic process that drives the amplification of SIE variations, rather than the sea‐ice‐drift‐related dynamic process. Compared to 1979–1998, the Southern Annular Mode in the preceding spring shows a closer linkage with the Weddell Sea SIE in 1999–2021 through a stronger and more prolonged impact on sea surface temperature, which thermodynamically modulates local sea ice via changing surface heat and radiation fluxes. Our study helps advance the understanding of extreme low Antarctic‐SIE records occurring in recent decades and improve future projections of the Antarctic sea‐ice variability.
Plain Language Summary
Unlike Arctic sea ice, which has significantly declined in recent decades, Antarctic sea ice possesses a moderate increase with large spatial and seasonal discrepancies. The amount of austral‐summer sea ice extent (SIE) around the Antarctica exhibits more pronounced year‐to‐year variations in the 21st century. Interestingly, we found that the amplified SIE variation is most significant in the Weddell Sea, east of the Antarctic Peninsula. This amplified variations in Weddell Sea SIE apparently cannot be fully explained by anthropogenic forcing, suggesting an important role of internal variability in the Antarctic climate system. Our analyses showed that the late‐1990s changes in the Southern Annular Mode (SAM)—the predominant mode of climate variability in the extratropical Southern Hemisphere—might cause the interdecadal amplification of the summer sea‐ice variation in the Weddell Sea via the thermodynamic process.
Key Points
The year‐to‐year variability of summer sea‐ice extent in the Weddell Sea, Antarctica, has significantly increased since 1998/1999
This interdecadal change in sea‐ice extent is dominated by changes in thermodynamic process rather than dynamic and mechanical processes
The Southern Annular Mode contributes to such a sea‐ice change via altering sea surface temperature and thus local thermodynamic processes
The mystery behind magnesium-induced bone formation is revealed by linking the neuropeptide(s) from sensory nerves with the osteogenic differentiation of stem cells in the periosteum. Zhang and ...colleagues' study sheds light on the development of magnesium pills or calcitonin gene-related peptide-delivery system for the prevention or treatment of osteoporosis.
For the first time, magnesium is shown to be beneficial for fracture healing at the weight-bearing site. In addition, calcitonin gene-related peptide-delivery system will also be another translational direction, as the promotive role of calcitonin gene-related peptide in fracture healing is supportive. These cost-effective and innovative treatment approaches will definitely bring a reduction not only in the suffering of patients, but also in the economic burden for their families and our society.
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