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All-vanadium redox flow battery (VRFB) is a promising energy storage technique. Flow fields play a crucial role in distributing the electrolyte into the electrode uniformly, but their performance characteristics under different electrode parameters are still unclear. In this work, taking the total pressure drop and total overpotential as performance characterizations, the influence of electrode parameters and operating conditions on the performance of serpentine flow field (SFF) and interdigitated flow field (IFF) are experimentally investigated. It is found that the battery with IFF exhibits lower pressure drop than that with SFF because of the shunt effect of IFF on electrolyte. In terms of promoting the uniform distribution of the electrolyte into the electrode, the SFF outperforms IFF when the electrode porosity is higher than 0.810, but the performance of SFF and IFF could be reversed as the electrode porosity decreases to 0.714, indicating that there may be a performance reversal between SFF and IFF when the electrode porosity decreases from 0.810 to 0.714. Moreover, the increase of current density, the decrease of electrolyte input, and the decrease of electrode thickness strengthen the performance reversal at low electrode porosity. The results well explain the debate on the superiority of IFF and SFF and the discussion on the preference between flow fields and electrode thickness in literatures and provide guidance for the selection of optimal flow field in VRFBs. [ABSTRACT FROM AUTHOR]

Amphibole‐rich rocks constitute significant components of the mid‐ to lower continental crust, particularly in active orogens characterized with thick and hot crusts. Nevertheless, experimental data on their viscosity remain scarce. We conducted axial compression deformation experiments on synthetic amphibolites under temperature and pressure conditions resembling deep sections of overthickened crust. A novel flow law for a calcic‐amphibole‐rich rock (80% amphibole +20% garnet) in the dislocation creep regime is derived from these experiments. Contrary to common assumptions, our results reveal that calcic‐amphibolite is 1‐2 orders of magnitude weaker than plagioclase‐rich amphibolite, granulite, or gabbro. A calcic‐amphibole‐rich, low viscosity deep crust may not only support the "channel flow" model proposed for the Tibetan Plateau but also explain the observed high crustal seismic anisotropy in the region. Plain Language Summary: The rarity of earthquakes despite strong deformation in the deep crust of mountain belts produced by continental collisions, such as the Himalayas, implies that the deep continental crust is rather weak, easily dissipating imposed stresses by ductile deformation. The major components of the orogenic lower crust are plagioclase, amphibole, pyroxene, and garnet. Experimental data on the ductile deformation of coarse‐grained amphibole‐rich rocks was until now missing. We present new deformation experiments, from which we derive a flow law for an amphibolitic aggregate (80% amphibole +20% garnet). These data show high volumes of amphibole should result in high ductility and, hence, low strength in the deep crust, which should be considered when modeling the mechanical behavior of the lower crust during continental collisional. An amphibole‐rich deep crust also accounts for the high crustal seismic anisotropy in southern Tibet. Key Points: Experimentally based flow law for dislocation creep of calcic‐amphibole‐rich (80 wt.%) rocksA calcic‐amphibole‐rich deep crust supports the "channel flow" model in southern TibetExperimental amphibole crystal preferred orientations (CPO) may explain deep crustal seismic anisotropy [ABSTRACT FROM AUTHOR]

The influence of soil properties on spatial yield variability of potato (Solanum tuberosum L.) can be employed as a foundation for site-specific soil management. It is challenging to understand the mechanism of crop yield spatial variation. In this study, a Fourier transform-based spatial variation analysis method is proposed for potato yield. The current work investigated the relationship of soil properties (including texture, moisture, and nitrate-nitrogen) to the variability of potato yield on 28 ha center-pivot irrigated fields located in northwest China from 2015 to 2017. Statistics and geostatistics are applied to evaluate the spatial variability of potato yield and soil properties; correlation analysis, partial least squares regression (PLSR) and the Fourier transform-based spatial variation analysis method are applied to explore the driving factors of the spatial variability of potato yield. Compared with other soil factors, soil moisture content and potato yield had more similar spatial structure, with similar semi-variance model and parameters. A negative correlation between soil moisture content and yield has been found in the first two years. According to partial least squares regression (PLSR), soil properties can only explain 24%, 25%, and 3% of the potato yield variation in 2015, 2016, and 2017. However, the Fourier transform-based spatial variation analysis method indicated that about 80% of potato yield variation has been explained by soil texture (49%), soil moisture (30%), soil nitrate-nitrogen (10%), and other factors (10%). The contribution of multiple factors to yield spatial variation has been decomposed by the method based on Fourier transform. This method can be considered a new approach for studying spatial variation and a theoretical basis for precise field management. [ABSTRACT FROM AUTHOR]

Electrically biased graphene has been studied experimentally as a novel emitter of thermal radiation. However, there is as yet no systematic theory that quantifies the thermal radiation, heat transfer, and electrical properties of electrically biased graphene. To study the thermal transport properties systematically, a heat conduction model is developed and exploited in this paper. The temperature distribution and heat conduction coefficient of graphene under different bias voltages are obtained using our theoretical model. The I–V curve and the relationship between the radiant power and input voltage of graphene are then obtained. This work could help design a novel efficient wavelength-adjustable thermal radiation source. [ABSTRACT FROM AUTHOR]