Mg-Based Micromotors with Motion Responsive to Dual Stimuli

Mg-based micromotors have emerged as an extremely attractive artificial micro/nanodevice, but suffered from uncontrollable propulsion and limited motion lifetime, restricting the fulfillment of complex tasks. Here, we have demonstrated Mg-based micromotors composed of Mg microspheres asymmetrically coated with Pt and temperature-sensitive poly(N-isopropylacrylamide) (PNIPAM) hydrogel layers in sequence. They can implement different motion behaviors stemming from the driving mechanism transformation when encountering catalyzed substrates such as H2O2 and respond to both H2O2 concentration and temperature in aqueous environment. The as-constructed Mg-based micromotors are self-propelled by Pt-catalyzed H2O2 decomposition following the self-consuming Mg-H2O reaction. In this case, they could further generate bilateral bubbles and thus demonstrate unique self-limitation motion like hovering when the phase transformation of PNIPAM is triggered by decreasing temperature or when the H2O2 concentration after permeating across the PNIPAM hydrogel layer is high enough to facilitate bubble nucleation. Our work for the first time provides a stimuli-induced “hovering” strategy for self-propelled micromotors, which endows Mg-based micromotors with an intelligent response to the surroundings besides the significant extension of their motion lifetime.

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Adaptability of Ultrasonic Lamb Wave Touchscreen to the Variations in Touch Force and Touch Area

Sensors ◽

10.3390/s21051736 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1736

Author(s):

Zengchong Yang ◽

Xiucheng Liu ◽

Bin Wu ◽

Ren Liu

Keyword(s):

Lamb Wave ◽

Weight Coefficient ◽

The Self ◽

Reference Database ◽

Learning Method ◽

Improved Method ◽

Large Area ◽

Localization Model ◽

Reference Databases ◽

First Time

Previous studies on Lamb wave touchscreen (LWT) were carried out based on the assumption that the unknown touch had the consistent parameters with acoustic fingerprints in the reference database. The adaptability of LWT to the variations in touch force and touch area was investigated in this study for the first time. The automatic collection of the databases of acoustic fingerprints was realized with an experimental prototype of LWT employing three pairs of transmitter–receivers. The self-adaptive updated weight coefficient of the used transmitter–receiver pairs was employed to successfully improve the accuracy of the localization model established based on a learning method. The performance of the improved method in locating single- and two-touch actions with the reference database of different parameters was carefully evaluated. The robustness of the LWT to the variation of the touch force varied with the touch area. Moreover, it was feasible to locate touch actions of large area with reference databases of small touch areas as long as the unknown touch and the reference databases met the condition of equivalent averaged stress.

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Kaolin based protective barrier in municipal landfills against adverse chemo-mechanical loadings

Scientific Reports ◽

10.1038/s41598-021-89787-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Partha Das ◽

Tadikonda Venkata Bharat

Keyword(s):

Ionic Strength ◽

High Ionic Strength ◽

The Self ◽

Design Parameters ◽

Layered System ◽

Geosynthetic Clay Liners ◽

Clay Liners ◽

Landfill Liner ◽

First Time ◽

Applied Stresses

AbstractIn this work, we assess the self-sealing and swelling ability of the compacted granular bentonite (GB) under an inorganic salt environment and induced overburden stresses from the landfill waste. The laboratory permeation tests with high ionic strength salt solutions reveal that the GB fails to seal and exhibits a significant mechanical collapse under different applied stresses. The applicability of GB in the form of geosynthetic clay liners as the bottom liner facilities in landfills that produce high ionic strength salt leachates, therefore, remains a serious concern. We propose an additional barrier system based on kaolin, for the first time, to address this problem. The proposed kaolin-GB layered system performs satisfactorily in terms of its sealing and swelling ability even in adverse saline conditions and low overburden stresses. The kaolin improves the osmotic efficiency of the self and also helps the underlying GB layer to seal the inter-granular voids. The estimated design parameters by through-diffusion test suggest that the kaolin-GB layered system effectively attenuates the permeant flux and suitable as a landfill liner.

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A molecular dynamics study on formation of the self-accommodation microstructure during phase transformation

Journal of Material Science and Technology ◽

10.1016/j.jmst.2019.04.035 ◽

2019 ◽

Vol 35 (11) ◽

pp. 2638-2646 ◽

Cited By ~ 3

Author(s):

Zhi-peng Sun ◽

Jin-yu Zhang ◽

Fu-zhi Dai ◽

Ben Xu ◽

Wen-zheng Zhang

Keyword(s):

Molecular Dynamics ◽

Phase Transformation ◽

The Self

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Transformation behavior of yttria stabilized tetragonal zirconia polycrystal–TiB2 composites

Journal of Materials Research ◽

10.1557/jmr.2001.0294 ◽

2001 ◽

Vol 16 (7) ◽

pp. 2158-2169 ◽

Cited By ~ 21

Author(s):

B. Basu ◽

J. Vleugels ◽

O. Van Der Biest

Keyword(s):

Thermal Expansion ◽

Phase Transformation ◽

Low Temperature ◽

Tetragonal Zirconia ◽

Mechanical Analysis ◽

Transformation Behavior ◽

Thermal Expansion Data ◽

Thermally Induced ◽

First Time ◽

Tetragonal Zirconia Polycrystal

The objective of the present article is to study the influence of TiB2 addition on the transformation behavior of yttria stabilized tetragonal zirconia polycrystals (Y-TZP). A range of TZP(Y)–TiB2 composites with different zirconia starting powder grades and TiB2 phase contents (up to 50 vol%) were processed by the hot-pressing route. Thermal expansion data, as obtained by thermo-mechanical analysis were used to assess the ZrO2 phase transformation in the composites. The thermal expansion hysteresis of the transformable ceramics provides information concerning the transformation behavior in the temperature range of the martensitic transformation and the low-temperature degradation. Furthermore, the transformation behavior and susceptibility to low-temperature degradation during thermal cycling were characterized in terms of the overall amount and distribution of the yttria stabilizer, zirconia grain size, possible dissolution of TiB2 phase, and the amount of residual stress generated in the Y-TZP matrix due to the addition of titanium diboride particles. For the first time, it is demonstrated in the present work that the thermally induced phase transformation of tetragonal zirconia in the Y-TZP composites can be controlled by the intentional addition of the monoclinic zirconia particles into the 3Y-TZP matrix.

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A dissipative particle dynamics simulation study on phase diagrams for the self-assembly of amphiphilic hyperbranched multiarm copolymers in various solvents

Soft Matter ◽

10.1039/c7sm01170a ◽

2017 ◽

Vol 13 (36) ◽

pp. 6178-6188 ◽

Cited By ~ 20

Author(s):

Haina Tan ◽

Chunyang Yu ◽

Zhongyuan Lu ◽

Yongfeng Zhou ◽

Deyue Yan

Keyword(s):

Phase Diagrams ◽

Simulation Study ◽

Self Assembly ◽

Dissipative Particle Dynamics ◽

Particle Dynamics ◽

The Self ◽

Dynamics Simulation ◽

Dynamics Simulations ◽

First Time ◽

Dissipative Particle Dynamics Simulation

This work discloses for the first time the self-assembly phase diagrams of amphiphilic hyperbranched multiarm copolymers in various solvents by dissipative particle dynamics simulations.

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SSL-Unet: A Self-Supervised Learning Strategy Base on U-Net for Retinal Vessel Segmentation

10.36227/techrxiv.16823236.v1 ◽

2021 ◽

Author(s):

Chao Ma

Keyword(s):

Supervised Learning ◽

Learning Strategy ◽

Retinal Vessel ◽

Vessel Segmentation ◽

The Self ◽

Supervised Training ◽

Vascular Segmentation ◽

Retinal Vessel Segmentation ◽

Retinal Segmentation ◽

First Time

We propose a SSL-Unet model for retinal vascular segmentation as well as two self-supervised training strategies. The strategy can help the self-supervised module to learn pseudo labels for improving the segmentation performance. Moreover, the fusion of both self-supervised and supervised paradigms is applied to retinal segmentation for the first time. Meanwhile, it can also be extended to any segmentation network.

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How to Use PIR for Renewal of Certification

Pediatrics in Review ◽

10.1542/pir.16.1.3 ◽

1995 ◽

Vol 16 (1) ◽

pp. 3-3

Author(s):

R J H

Keyword(s):

American Academy ◽

Education Program ◽

The Self ◽

Certification Program ◽

Educational Objectives ◽

Self Assessment ◽

American Academy Of Pediatrics ◽

First Time

During 1995, many pediatricians will participate for the first time in the Pediatric Renewal of Certification Program (PRCP). Since Pediatrics in Review (PIR) and the Pediatrics Review and Education Program (PREP) began in 1979, their material has been integrated with the American Board of Pediatrics (ABP) renewal of certification program. The ABP sets the educational objectives (now called content specifications) and develops the examinations. The American Academy of Pediatrics (AAP) develops PREP education materials, PIR, and the Self-Assessment Exercise based on these. Each year PIR covers about 1000 of the more than 4000 content specifications, including at least half of the 900 selected as the basis each year for the cognitive examination.

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A self-assembly based on a hydrogel interface: facile, rapid, and large-scale preparation of colloidal photonic crystals

Materials Chemistry Frontiers ◽

10.1039/d0qm00266f ◽

2020 ◽

Vol 4 (8) ◽

pp. 2409-2417

Author(s):

Mengfan Wu ◽

Chuyan Zhang ◽

Fujing Wei ◽

Huifang An ◽

Xiaqing Wang ◽

...

Keyword(s):

Photonic Crystals ◽

Self Assembly ◽

Large Scale ◽

The Self ◽

Colloidal Photonic Crystals ◽

Large Scale Preparation ◽

Scale Preparation ◽

First Time

This is the first time that a hydrogel interface has been used as an assembly interface for the self-assembly of photonic crystals with excellent performances.

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Synthesis and electronic properties of π-expanded carbazole-based porphyrins

Chemical Communications ◽

10.1039/c9cc05079e ◽

2019 ◽

Vol 55 (68) ◽

pp. 10162-10165 ◽

Cited By ~ 6

Author(s):

Chihiro Maeda ◽

Yumi Tanaka ◽

Takuma Shirakawa ◽

Tadashi Ema

Keyword(s):

Electronic Properties ◽

First Time ◽

Pt Catalyzed

Peripheral π-expansion of carbazole-based porphyrins was achieved for the first time by the Pt-catalyzed cyclization and the incorporation of a benzocarbazole unit.

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AuNPs-Based Thermoresponsive Nanoreactor as an Efficient Catalyst for the Reduction of 4-Nitrophenol

Nanomaterials ◽

10.3390/nano8120963 ◽

2018 ◽

Vol 8 (12) ◽

pp. 963

Author(s):

Wei Liu ◽

Xiaolian Zhu ◽

Chengcheng Xu ◽

Zhao Dai ◽

Zhaohui Meng

Keyword(s):

Aqueous Solution ◽

Electron Transfer ◽

Phase Transformation ◽

Catalytic Activity ◽

Catalytic Efficiency ◽

Environmental Pollutant ◽

Temperature Sensitive ◽

Efficient Catalyst ◽

Catalytic Rate ◽

Silica Core

A new AuNPs-based thermosensitive nanoreactor (SiO2@PMBA@Au@PNIPAM) was designed and prepared by stabilizing AuNPs in the layer of poly(N,N’-methylenebisacrylamide) (PMBA) and subsequent wrapping with the temperature-sensitive poly(N-isopropylacrylamide) (PNIPAM) layer. The new nanoreactor exhibited high dispersibility and stability in aqueous solution and effectively prevented the aggregation of AuNPs caused by the phase transformation of PNIPAM. The XPS and ATR-FTIR results indicated that AuNPs could be well stabilized by PMBA due to the electron transfer between the N atoms of amide groups in the PMBA and Au atoms of AuNPs. The catalytic activity and thermoresponsive property of the new nanoreactor were invested by the reduction of the environmental pollutant, 4-nitrophenol (4-NP), with NaBH4 as a reductant. It exhibited a higher catalytic activity at 20 °C and 30 °C (below LCST of PNIPAM), but an inhibited catalytic activity at 40 °C (above LCST of PNIPAM). The PNIPAM layer played a switching role in controlling the catalytic rate by altering the reaction temperature. In addition, this nanoreactor showed an easily recyclable property due to the existence of a silica core and also preserved a rather high catalytic efficiency after 16 times of recycling.

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