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A smart magnetorheological elastomer peristaltic pump (MRE-PP) realizes controlled movements to convey Newtonian and non-Newtonian fluids under various scheduling policies for electromagnets. Although the structure of the basic element consisted of a magnetorheological elastomer tube and an electromagnet is very succinct, the capability of fluid conveying is dramatically improved when the magnetorheological elastomer peristaltic pump composed of more elements in series is employed. Besides, scheduling policies and the length of the magnetorheological elastomer tube, as another two significant factors, also have remarkable effects on backflow, pumped fluid volume, and viscosity of blood. Various scheduling policies are designed to realize fluid conveying with relatively high pumped volume for non-Newtonian fluid. Meanwhile, low destructiveness is demonstrated in the designed magnetorheological elastomer peristaltic pumps, allowing a potential application of conveying stress sensitive fluids.

Background Allelopathic rice releases allelochemicals through its root systems, thereby exerting a negative effect on paddy weeds. This research aimed to evaluate the relationship between fine-root traits and the rice allelopathic potential at the seedling stage. Methods Two allelopathic rice cultivars, ‘PI312777’ and ‘Taichung Native1,’ and one non-allelopathic rice cultivar, ‘Lemont,’ were grown to the 3–6 leaf stage in a hydroponic system. Their fine roots were collected for morphological trait (root length, root surface area, root volume, and root tips number) in smaller diameter cutoffs and proliferative trait (root biomass) analysis. Their root-exudates were used for quantitative analysis of phenolic acids contents and an evaluation of allelopathic potential. Correlation analysis was also used to assess whether any linear relationships existed. Results Our results showed that allelopathic rice cultivars had significantly higher fine-root length having diameters <0.2 mm, more root tips number, and greater root biomass, coupled with higher allelopathic potential and phenolic acid contents of their root exudates, comparing with non-allelopathic rice cultivar. These fine-root traits were significantly-positively correlated to allelopathic inhibition and total phenolic contents in rice root-exudates. However, there were not significant correlations among the rice allelopathic potential and total phenolic acid contents of rice root-exudates with the root length, root surface area, and root volume of fine root in diameter >0.2 mm. Discussion Our results implied that fine-root traits appears to be important in understanding rice allelopathy at the seedling stage. The high allelopathic potential of rice cultivars might be attributed to their higher length of fine roots <0.2 mm in diameter and more number of root tips of fine root, which could accumulate and release more allelochemicals to solutions, thereby resulting in high inhibition on target plants. The mechanisms regulating this process need to be further studied.

Metallic current collectors with three-dimensional (3D) porous structures have been considered as ideal hosts for Li metal anodes because of their ability to accommodate anode volume fluctuations and suppress Li dendrite formation. However, in a conductive 3D porous framework, Li preferentially deposits at the top surface, resulting in uneven deposition, and ultimately forms Li dendrites. Herein, we propose a deposition regulation strategy by fabricating a lithiophilic nanoporous CuSnAl layer at the bottom of a porous Cu foam to induce bottom-up and dense Li deposition. The as-prepared CuSnAl@Cu foam demonstrates enhanced Li deposition reversibility with a lifespan over 2000 h in symmetrical cells at 1 mA cm −2 . Full cells coupled with lithiated CuSnAl@Cu foam and a LiFePO 4 cathode exhibit outstanding electrochemical performance, with a Coulombic efficiency (CE) of 99.6% over 300 cycles, which is much better than that using a pure Cu foam or Cu foil. Moreover, the electric field distribution at the CuSnAl layer has been directly observed to disclose the intrinsic mechanism of bottom-up Li growth. This design of 3D metallic current collectors with a lithiophilicity gradient provides new insights into stable Li metal anodes, and thus, into Li metal batteries.

A microrheological method is employed for the first time to continuously and undisturbedly monitor variations of viscoelasticity of magnetorheological elastomers (MREs) based on silica-coated carbonyl iron particles (SiCIPs)-filled silicone during the curing process. Results indicate that the elasticity of MREs dramatically increases with increasing magnetic field intensity, which is much more significant in comparison with the slow process of silicone curing at 25 % and 40 % SiCIPs. The formations of chain-like structure of SiCIPs and cured network of silicone are recognized, both contributing to the rheology of MREs, suggesting the possibility of developing a facile method for adjusting the rheology and fixing the structure of a wide range of MREs by applying magnetic field during the curing of matrix.

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Creating long-lived topological textured liquid crystals (LCs) in confined nonspherical space is of significance in both generations of structures and fundamental studies of topological physics. However, it remains a great challenge due to the fluid character of LCs and the unstable tensional state of transient nonspheres.Here, we realize a rich series of topological textures confined in nonspherical geometries by drop impact assembly (DIA) of graphene oxide (GO) aqueous LCs. Various highly curved nonspherical morphologies of LCs were captured by gelator bath, generating distinct out-ofequilibrium yet long-lived macroscopic topological textures in 3D confinement. Our hydrodynamic investigations on DIA processes reveal that the shear-thinning fluid behavior of LCs and the arrested GO alignments mainly contribute to the topological richness in DIA. Utilizing the shaping behavior of GO LCs compared to other conventional linear polymers such as alginate, we further extend the DIA methodology to design more complex yet highly controllable functional composites and hybrids. This work thus reveals the potential to scale production of uniform yet anisotropic materials with rich topologic textures and tailored composition.

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