Effects of nonlinear velocity slip and temperature jump onpseudo-plastic power-law fluid over moving permeable surface in presence of magnetic field

Flow and heat transfer of a pseudo-plastic power-law fluid over a stretching permeable surface with the magnetic effect is investigated. In the boundary conditions,the nonlinear temperature jump and the velocity slip are considered. Semi-similarity equations are obtained and solved by bvp4c with MATLAB. The problem can be considered as an extension of the previous work done by Mahmoud(Mahmoud, M. A. A. Slip velocity effect on a non-Newtonian power-law fluid over a moving permeable surface with heat generation. Mathematical and Computer Modelling, 54, 1228–1237(2011)). Efforts are made to discuss the effects of the power-law number, slip velocity, and temperature jump on the dimensionless velocity and temperature distribution.

Size-refinement enhanced flexibility and electrochemical performance of MXene electrodes for flexible waterproof supercapacitors

Increasing mechanical flexibility without sacrificing electrochemical performance of the electrode material is highly desired in the design of flexible electrochemical energy storage devices.In metal-related materials science,decreasing the grain size introduces more grain boundaries;this stops dislocations and crack propagation under deformation,and results in increased strength and toughness.However,such a size refinement effect has not been considered in the mechanical properties,particle stacking,wetting,and electrochemical performances of flexible supercapacitor electrodes.In this paper,MXene was used as an electrode material to study the size refinement effect of flexible supercapacitors.Size refinement improved the strength and toughness of the MXene electrodes,and this resulted in increased flexibility.Finite elemental analysis provided a theoretical understanding of size refinement-increased flexibility.Moreover,the size refinement also improved the specific surface area,electric conductance,ion transportation,and water wetting properties of the electrode,and the size refinement provided highly increased energy density and power density of the MXene supercapacitors.A highly flexible,water-proof supercapacitor was fabricated using size-refined MXene.The current study provides a new viewpoint for designing tough and flexible energy storage electrodes.The size refinement effect may also be applicable for metal ion batteries and electronic and photo devices composed of MXene and other nanoparticles.

Review on Fiber-Based Thermoelectrics:Materials,Devices,and Textiles

With the development and prosperity of Internet of Things(IoT)technology,wearable electronics have brought fresh changes to our lives.The demands for low power consumption and mini-type wearable power systems for wearable electronics are more urgent than ever.Thermoelectric materials can efficiently convert the temperature difference between body and environment into electrical energy without the need for mechanical components,making them one of the ideal candidates for wearable power systems.In recent years,a variety of high-performance thermoelectric materials and processes for the preparation of large-scale single-fiber devices have emerged,driving the application of flexible fiber-based thermoelectric generators.By weaving thermoelectric fibers into a textile that conforms to human skin,it can achieve stable operation for long periods even when the human body is in motion.In this review,the complete process from thermoelectric materials to single-fiber/yarn devices to thermoelectric textiles is introduced comprehensively.Strategies for enhancing thermoelectric performance,processing techniques for fiber devices,and the wide applications of thermoelectric textiles are summarized.In addition,the challenges of ductile thermoelectric materials,system integration,and specifications are discussed,and the relevant developments in this field are prospected.

Structural and biochemical basis of Arabidopsis FERONIA receptor kinase-mediated early signaling initiation

Accumulating evidence indicates that early and essential events for receptor-like kinase(RLK)function involve both autophosphorylation and substrate phosphorylation.However,the structural and biochemical basis for these events is largely unclear.Here,we used RLK FERONIA(FER)as a model and crystallized its core kinase domain(FER-KD)and two FER-KD mutants(K565R,S525A)in complexes with ATP/ADP and Mg^(2+) in the unphosphorylated state.Unphosphorylated FER-KD was found to adopt an unexpected active conformation in its crystal structure.Moreover,unphosphorylated FER-KD mutants with reduced(S525A)or no catalytic activity(K565R)also adopt similar active conformations.Biochemical studies revealed that FER-KD is a dual-specificity kinase,and its autophosphorylation is accomplished via an intermolecular mechanism.Further investigations confirmed that initiating substrate phosphorylation requires autophosphorylation of the activation segment on T696,S701,and Y704.This study reveals the structural and biochemical basis for the activation and regulatory mechanism of FER,providing a paradigm for the early steps in RLK signaling initiation.

Concise and efficient direct-view generation of arbitrary cylindrical vector beams by a vortex half-wave plate

A concise, efficient, and practical direct-view scheme is presented to generate arbitrary cylindrical vector(CV)beams, including CV beams, vortex beams, and cylindrical vector vortex(CVV) beams, by a vortex half-wave plate(VHP). Six kinds of first-order and other high-order CV beams, such as azimuthally polarized(AP) beams, antivortex radial polarization mode beams, and three-order AP beams, are formed by simply rotating a half-wave plate. The Stokes parameters and double-slit interference of multitype CV beams are investigated in detail.The polarization parameters, including degree of polarization, polarization azimuth, and ellipticity, are obtained,which demonstrates the efficient generation of CV beams. In addition, the double-slit interference experiment is introduced in the setup, and fringe misplacement and tilt appear for CVV beams, in which the misplacement number M is 2P+1 for P ≤ 2 and 2P-1 for P ≥ 3, where P is the polarization order number, and the fringe tilt offset is positively related to the topological charge number l of CVV beams. In addition, new types of VHPs can be formed by cascading two or more VHPs when the types of available VHPs are limited, assisting in more flexible generation of multitype CV beams. It is experimentally demonstrated that arbitrary CV beams with high quality are effectively achieved by the proposed setup, and the double-slit interference method can be utilized to determine and analyze CV beams rapidly and concisely by practical performance, which shows the potential to be implemented as a commercial device.

Thermally drawn multifunctional fibers: Toward the next generation of information technology

As the fundamental building block of optical fiber communication technology,thermally drawn optical fibers have fueled the development and prosperity of modern information society.However,the conventional step-index configured silica optical fibers have scarcely altered since their invention.In recent years,thermally drawn multifunctional fibers have emerged as a new yet promising route to enable unprecedented development in information technology.By adopting the well-developed preform-to-fiber manufacturing technique,a broad range of functional materials can be seamlessly integrated into a single fiber on a kilometer length scale to deliver sophisticated functions.Functions such as photodetection,imaging,acoustoelectric detection,chemical sensing,tactile sensing,biological probing,energy harvesting and storage,data storage,program operation,and information processing on fiber devices.In addition to the original light-guiding function,these flexible fibers can be woven into fab-rics to achieve large-scale personal health monitoring and interpersonal com-munication.Thermally drawn multifunctional fibers have opened up a new stage for the next generation of information technology.This review article summarizes an overview of the basic concepts,fabrication processes,and developments of multifunctional fibers.It also highlights the significant pro-gress and future development in information applications.