RuO2 is considered as the state‐of‐the‐art electrocatalyst for the oxygen evolution reaction (OER) in acidic media. However, its practical application is largely hindered by both the high reaction ...overpotential and severe electrochemical corrosion of the active centers. To overcome these limitations, innovative design strategies are necessary, which remains a great challenge. Herein, robust interface Ru centers between RuO2 and graphene, via a controllable oxidation of graphene encapsulating Ru nanoparticles, are presented to efficiently enhance both the activity and stability of the acidic OER. Through precisely controlling the reaction interface, a much lower OER overpotential of only 227 mV at 10 mA cm−2 in acidic electrolyte, compared with that of 290 mV for commercial RuO2, but a significantly higher durability than the commercial RuO2, are achieved. Density functional theory (DFT) calculations reveal that the interface Ru centers between the RuO2 and the graphene can break the classic scaling relationships between the free energies of HOO* and HO* to reduce the limiting potential, rendering an enhancement in the intrinsic OER activity and the resistance to over‐oxidation and corrosion for RuO2.
The robust interface Ru centers between RuO2 and graphene are found to boost both activity and stability for the acidic oxygen evolution reaction (OER), exhibiting a much lower OER overpotential of only 227 mV at 10 mA cm−2 compared with that of 290 mV for commercial RuO2 but a significantly higher durability than the commercial RuO2.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Next-generation non-volatile memories with ultrafast speed, low power consumption, and high density are highly desired in the era of big data. Here, we report a high performance memristor based on a ...Ag/BaTiO
/Nb:SrTiO
ferroelectric tunnel junction (FTJ) with the fastest operation speed (600 ps) and the highest number of states (32 states or 5 bits) per cell among the reported FTJs. The sub-nanosecond resistive switching maintains up to 358 K, and the write current density is as low as 4 × 10
A cm
. The functionality of spike-timing-dependent plasticity served as a solid synaptic device is also obtained with ultrafast operation. Furthermore, it is demonstrated that a Nb:SrTiO
electrode with a higher carrier concentration and a metal electrode with lower work function tend to improve the operation speed. These results may throw light on the way for overcoming the storage performance gap between different levels of the memory hierarchy and developing ultrafast neuromorphic computing systems.
Massive landslides over large regions can be triggered by heavy rainfalls or major seismic events. Mapping regional landslides quickly is important for disaster mitigation. In recent years, deep ...learning methods have been successfully applied in many fields, including landslide automatic identification. In this work, we proposed a deep learning approach, the ResU-Net, to map regional landslides automatically. This method and a baseline model (U-Net) were collectively tested in Tianshui city, Gansu province, where a heavy rainfall triggered more than 10,000 landslides in July 2013. All models were performed on a 3-band (near infrared, red, and green) GeoEye-1 image with a spatial resolution of 0.5 m. At such a fine spatial resolution, the study area is spatially heterogeneous. The tested study area is 128 km2, 80% of which was used to train models and the remaining 20% was used to validate accuracy of the models. This proposed ResU-Net achieved higher accuracy than the baseline U-Net model in this mountain region, where F1 improved by 0.09. Compared with the U-Net model, this proposed model (ResU-Net) performs better in discriminating landslides from bare floodplains along river valleys and unplanted terraces. By incorporating environmental information, this ResU-Net may also be applied to other landslide mapping, such as landslide susceptibility and hazard assessment.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Using two nano-porous pseudo carbon paste electrodes (Nano-PPCPEs) as the working electrodes, a saturated calomel electrode as the reference electrode, and a Pt electrode as the counter electrode to ...form a four-electrode system, a novel type of glutamate-acetylcholine electrochemical biosensor array was successfully fabricated. It was shown that the biosensor array displayed a high selectivity and sensitivity and the selective and simultaneous determination of glutamate and acetylcholine (ATCh) is feasible. For L-glutamate, a linear range from 5 x 10(-7) M to 1 x 10(-5) M with the detection limit of 2.5 x 10(-7) M was demonstrated, while for ATChl the linear range is from 5 x 10(-6) M to 2 x 10(-4) M with the detection limit of 1.5 x 10(-7) M. This research means a possibility to simultaneously detect more neurotransmitters with a nano-PPCPEs electrochemical biosensor array.
The East Asian summer monsoon (EASM) is essential for the livelihoods of billions of people in East and Southeast Asia. Its present features and evolution history of the Quaternary have been well ...studied, yet how did EASM operate in much older geological times, especially before the late Miocene, is relatively less constrained. Scientific drillings conducted in the South China Sea (SCS) offer excellent opportunities to resolve this issue to a certain extent considering the EASM has been prevailing in this area since at least the earliest Miocene. In this study, mineralogical and stratigraphic studies were carried out on the middle Miocene pelagic reddish clay recovered at International Ocean Discovery Program Site U1433 using clay mineralogical and natural gamma radiation data. Our results show that the smectite content and illite crystallinity of the deep SCS clay were direct consequences of the EASM intensity varying in precession rhythm and modulated by eccentricity cycles. A high-resolution temporal framework constructed with onboard age controls and cyclostratigraphic analyses demonstrates that the pelagic reddish clay from Site U1433 was accumulated from 17.17 to 12.69 Ma. During this period, deep-sea sedimentation of the SCS was controlled by the EASM and influenced by the sea-level change. Importantly, clay mineral is proved to be an efficient terrigenous standard of astronomical tuning and stratigraphic correlation for pelagic sediments. It is also verified that the EASM intensified during the Miocene Climatic Optimum and the following Middle Miocene Climate Transition, and induced higher humidity and seasonality, respectively. Then, the EASM gradually weakened since the expansion of the East Antarctic Ice Sheet.
•A standard process for building age models of pelagic sediments is proposed.•The first high-resolution middle Miocene time framework in the deep South China Sea.•Pelagic clay minerals recorded the Miocene East Asian summer monsoon evolution.•Continental shelves buffered the middle Miocene sedimentation in the deep sea.•The South China Sea's reddish clay composition is homogeneous in the oceanic basin.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Carbon-based sandwich structures are constructed via highly conductive surface and porous spacers, which exhibit hydro-sensitive electromagnetic shielding performance via changing the water loadings ...in the spacers. The results highlighted hydro-sensitive electromagnetic shielding structures as smart electromagnetic response materials for self-tunable capability.
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•Carbon-based sandwich structures of EMI shielding are prepared.•Hydro-stimulus is used for tuning the shielding performance.•Smart electromagnetic shielding structures hold self-tunable capability.•Water molecules enhance the polar interface for performance change.
Since smart materials and structures are highly pursued for their great advantages in self-adaptable, self-healing and self-recoverable capability upon environmental condition change, here we demonstrate hydro-sensitive smart sandwich structures with self-adaptable electromagnetic interference (EMI) shielding ability via constructing polymeric porous non-woven-based spacers into highly conductive pyrolytic graphite papers. The spacers play the critical role in tuning the electromagnetic response capability, leading to substantially varying the electromagnetic shielding performance of the sandwich structures upon various water loadings. With the presence of polar water molecules, the porous polymeric spacers were significantly changed via creating polar induced interfaces. According to the electromagnetic shielding performance at initial, wet and re-dried conditions, the results suggest two types of smart structures, namely EMI shielding function switchable and function enhanced EMI shielding structures, which promises a novel platform for designing hydro-stimulus smart materials and structures for electromagnetic response applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Secoisolariciresinol diglucoside (SDG) and tracheloside (TCL) are the main lignan components of flaxseed cake and safflower seed cake, which are by‐products of oil extraction. Both SDG and TCL are ...metabolized into mammalian lignan enterolactone (EL) with the involvement of intestinal bacteria. In this research, we evaluated the anti‐osteoporosis effects of SDG and the in vivo metabolites EL and enterodiol (ED) prepared in our previous work, as well as the newly isolated chemical constituents from safflower seed, including TCL, the lactone ring opening product of TCL (OTCL) and two alkaloids on the alloxan‐induced zebrafish model. All the compounds showed significant anti‐osteoporosis effects at 80 µM, with p < 0.05 for EL and p < 0.001 for other compounds compared with the model. SDG and TCL showed the most significant and concentration‐dependent effects, with p < 0.001 compared with model at 20 µM. The alkaloids, N‐coumaroylserotonin glucoside and N‐feruloylserotonin glucoside, also showed anti‐osteoporosis at 20 µM with p < 0.01, whereas EL, ED, and OTCL showed no significant effects. Quantitative real‐time polymerase chain reaction revealed that SDG and TCL upregulated the expression of osteogenic genes Runx2, SP7, OPG, Col1a1a, Alp, ON, OPN, and OCN in alloxan‐treated zebrafish. The in vivo metabolite of lignans, EL, showed significant anti‐inflammatory effect (p < 0.01) at 20 µM, which might also help to combat osteoporosis and other complications caused by excessive immune response in the body. The results provided scientific data for using the oil extraction by‐products as sources of anti‐osteoporosis compounds.
Practical Application
This study found that lignans in flaxseed cake and safflower seed cake exhibited anti‐osteoporosis effects by upregulating the expression of osteogenic genes, making the oil extraction by‐products sources of anti‐osteoporosis compounds.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Synthesizing antiferromagnets with correlated oxides has been challenging, owing partly to the markedly degraded ferromagnetism of the magnetic layer at nanoscale thicknesses. Here we report on the ...engineering of an antiferromagnetic interlayer exchange coupling (AF-IEC) between ultrathin but ferromagnetic La2/3Ca1/3MnO₃ layers across an insulating CaRu1/2Ti1/2O₃ spacer. The layer-resolved magnetic switching leads to sharp steplike hysteresis loops with magnetization plateaus depending on the repetition number of the stacking bilayers. The magnetization configurations can be switched at moderate fields of hundreds of oersted. Moreover, the AF-IEC can also be realized with an alternative magnetic layer of La2/3Sr1/3MnO₃ that possesses a Curie temperature near room temperature. The findings will add functionalities to devices with correlated-oxide interfaces.
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BFBNIB, NMLJ, NUK, ODKLJ, PNG, SAZU, UL, UM, UPUK
Carbon dots (CDs) are a type of carbon‐based luminescent material with a zero‐dimensional structure and a size of less than 10 nm, which are composed of sp2/sp3 hybrid carbon nuclei and surface ...functional groups. Because CDs has strong photoluminescence and good light absorption in the ultraviolet and near visible regions, it is an excellent candidate for photocatalytic applications. However, the use of nonmetallic doped CDs as photosensitizers for direct photocatalytic organic reactions has been limited to several scattered reports. Herein, we present nitrogen‐doped carbon dots (N‐CDs) that has a capability for not only produce reactive oxygen species (ROS), including superoxide anion radical (O2⋅−) and singlet oxygen (1O2), but also provide an unprecedented high activity of dehalogenative oxyalkylation of styrene with a yield of 93 %. This work develops a novel opportunity to utilize cost‐effective and easily accessible CDs for the advancement of photocatalysis.
We designed and fabricated nitrogen‐doped carbon dots (N‐CDs) by using citric acid and diethylenetriamine in a solvothermal method. N‐CDs has excellent ability to generate 1O2 and O2⋅− under irradiation and was further employed as photocatalysts to promote the high selectivity of dehalogenative oxyalkylation of styrene under the mediation of oxygen.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
With the growth of people's environmental awareness and the encouragement of government policies, the use of electric vehicles in logistics distribution is gradually increasing. In order to solve the ...dual demand of customers' simultaneous pick-up and delivery in the "last kilometer logistics", an electric vehicle routing problem with simultaneous pick-up and delivery and time window (EVRPSPDTW) is considered from the perspective of multi-objective distribution in this paper. Firstly, a decision-making model based on distribution cost and power consumption function is established. In this model, distribution cost includes transportation cost, vehicle use cost, penalty cost of not arriving on time and charging cost. Power consumption function is the energy loss caused by air resistance, tire rolling friction and transmission system. Secondly, a multi-objective genetic algorithm (NSGA-II) optimization solution with fast nondominated ranking and elite strategy is designed, and in view of the shortcomings of traditional NSGA-II, it is proposed to complete population initialization through greedy algorithm and random rules, introduce adaptive cross-mutation strategy in the chromosome crossing and mutation stage, and design three different neighborhood operators in mutation operation based on variant fitness function. Finally, the sensitivity analysis of traffic congestion coefficient further proves the effectiveness of the proposed model and the improved algorithm.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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