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The effective wetting and deposition of pesticide droplets on the leaf surface significantly affect the control of pests and diseases, and its mainly affected by the leaf surface properties and pesticide formulation properties. This article aims to investigate the wettability regulation mechanism and dynamic wetting properties of banana leaves, in order to intelligently design appropriate pesticide formulations. The micro-morphology of the banana leaves exhibits a micro-nano dual-scale structure with different microstructures and roughness on the adaxial side and abaxial side. Correspondingly, the wettability on the adaxial side of the banana leaf with higher roughness (R q = 71.1 nm) is always better than that on the abaxial side (R q = 42.5 nm). The droplet contact performance of droplets exhibits a strong concentration dependence of surfactants, which regulate the inter-species differences in the wettability of different pesticide formulations on both sides. Besides, the dynamic wetting process of pesticide droplets exhibits strong time dependence, by using a time series method to establish an AR (2) model, precise simulation and prediction of the contact angle changes on the adaxial side (R 2 = 0.9560) and abaxial side (R 2 = 0.8903) during the dynamic wetting process were achieved. The dynamic wetting model provides new insights into the spreading and deposition processes of droplets on leaves. This work provides a favorable reference for the study of the dynamic balance between wetting and adhesion properties of pesticide spray on leaf surfaces. [Display omitted] • The regulation mechanism of surfactant on the wettability on leaves was revealed. • A time-dependent dynamic wetting model was established. • Provide guidance for the design of formulations to achieve the desired wettability. [ABSTRACT FROM AUTHOR]

Due to the limited thermoelectric performance of polymers and intrinsic rigidness of inorganic materials, it is difficult to obtain n-type thermoelectric materials and devices with low-cost, excellent flexibility, and high performance. In this work, we have successfully synthesized n-type flexible free-standing thermoelectric films by a low-cost solvothermal method, which is composed of Bi 2 Se 3 nanosheets and single-wall carbon nanotubes (SWCNTs). Bi 2 Se 3 nanosheets with excellent crystallinity and rhombohedral morphology were grown on SWCNTs. The optimized Bi 2 Se 3 /SWCNTs composite films exhibited a high electrical conductivity of 292.7 S cm−1 and a Seebeck coefficient of − 42.4 μV K−1 at room temperature, eventually achieving an improved power factor of 52.7 μW m−1 K−2. Furthermore, the composite films exhibited excellent flexibility due to the interweaving of Bi 2 Se 3 nanosheets with SWCNTs, where the thermoelectric performance remained almost unchanged after 5000 bending cycles around a 3.5 mm radius rod. A thermoelectric device, composed of the optimized films, was constructed to further show the practicality, which generated a voltage and a power density of 11.5 mV and 86.2 μW cm−2 at a temperature gradient of 58 K, respectively. This work can provide support for the preparation of other n-type free-standing thermoelectric films with both high thermoelectric performance and excellent flexibility. [Display omitted] • N-type flexible Bi 2 Se 3 /SWCNTs thermoelectric composite films have been successfully synthesized by a low-cost solvothermal method. • The optimized composite films show high performance, which is the best among other Bi 2 Se 3 /CNTs flexible film materials. • The thermoelectric performance remains almost unchanged after 5000 bending cycles around a 3.5 mm radius rod. • A thermoelectric device assembled with eight-single-leg outputs 11.5 mV voltage and 86.2 μW cm−2 power density at a temperature gradient of 58 K. [ABSTRACT FROM AUTHOR]

• Optical constants of protein, carbohydrate and lipid were experimentally determined. • Isolations of protein, lipid and carbohydrate from Chlorella sp. were conducted. • Fitted formula of the refractive index was presented. An accurate knowledge of optical constant of protein, lipid and carbohydrate is important for analyzing radiative transport between cells. However, it is difficult to measure precisely the optical constant of these elements due to the complicated sample-making and the limitation of traditional measurement method. In this work, the double optical pathlength transmission method and the ellipsometry method (DOPTM-EM) were used to obtain the optical constants of protein, lipid and carbohydrate of Chlorella sp. (both solid-state and solution-state), solution-state egg protein and solution-state sucrose in the spectral range 300-1700 nm. Isolations of protein, lipid and carbohydrate from Chlorella sp. were conducted. For different types and states of protein, lipid and carbohydrate, the optical constants of these samples are different from each other. The refractive indices of protein and carbohydrate have obvious relationship with the existing state. A significant difference of absorption indices can be observed between the solution-state protein of Chlorella sp. and the egg protein. It is indicated that the amino acids composition of solution-state protein of Chlorella sp. differs from the egg protein. The absorption indices of solution-state carbohydrate do not agree with the solution-state sucrose. For the sake of applications, the fitted formula of the refractive index as a function of wavelength is presented. [ABSTRACT FROM AUTHOR]

The contact interaction between compliant mechanisms and external objects is a common occurrence in the field of grasping and manipulation. However, accurately modeling the large deformation and contact force/stress remains a challenging task. This paper presents a contact analysis method to evaluate the deformation and normal contact force/stress of compliant mechanisms with general-shape beams. The general beams are modeled by using the chained pseudo-rigid-body model (CPRBM). On basis of CPRBM framework, linear and distributed contact springs are introduced at the interface to represent the contact force. A numerical method is established to fast calculate the boundary penetrations, and a contact stiffness formulation is proposed based on the theory of elasticity. Then, the effect of contact interaction can be evaluated by the contact potential energy of contact springs, which is part of the system's total potential energy. By minimizing the potential energy function of the compliant system, the static equilibrium configuration and contact force/stress can be obtained easily. Numerical examples are used to verify the feasibility and accuracy of the proposed method. • A large-deflection contact analysis method considering contact stress distribution. • The large deformation of compliant mechanism is modeled by using CPRBM. • Linear contact springs are introduced to represent contact force/stress. • An analytical formulation of contact stiffness is established. • The proposed method is simple and straightforward. [ABSTRACT FROM AUTHOR]

• By etching Cu stabilizer, the joint resistance (R j) can be reduced by removing the cupric oxide of the surface layer and shortening the current path between the two YBCO layers. • Preferable electrical properties under applying bending deformation are achieved and proved by the bending tests and finite element simulations. The evidently enhanced I c retention is found by bending tests. The stress and strain of the YBCO layer can be reduced due to employ thinner etching joints. • The employment of spot welding can further enhance the strength at the edges of the joint and thereby alleviate the I c degradation. The YBa 2 Cu 3 O 7 − x coated conductor (YBCO CC) is one of the most promising superconducting materials for magnet applications because of its high critical current (I c) and low dependency of the I c on the external magnetic field. For magnet applications, plenty of joints are required to meet the connection of relatively short YBCO CC tapes. The bending properties of the joints inevitably become one of the critical factors that determine the performance of the superconducting magnet. In this paper, we fabricated the joints of YBCO CC tapes by etching Cu stabilizer and studied their bending properties under various bending diameter at 77 K and self-field. Compared with the soldering joint, lower joint resistance (R j) and preferable electrical properties under applying various bending deformation were achieved and proved by the bending strain tests and finite element simulations. This fabrication technique is a unique practicable solution to reduce the R j and improve the bending properties for the joints of YBCO CC tapes with thicker metal stabilizing layers in second generation high temperature superconductor (2G HTS) applications. [ABSTRACT FROM AUTHOR]