7 research outputs found
Polysulfide Catalytic Materials for Fast-Kinetic MetalâSulfur Batteries: Principles and Active Centers
Benefiting from the merits of low cost, ultrahigh-energy densities, and environmentally friendliness, metalâsulfur batteries (MâS batteries) have drawn massive attention recently. However, their practical utilization is impeded by the shuttle effect and slow redox process of polysulfide. To solve these problems, enormous creative approaches have been employed to engineer new electrocatalytic materials to relieve the shuttle effect and promote the catalytic kinetics of polysulfides. In this review, recent advances on designing principles and active centers for polysulfide catalytic materials are systematically summarized. At first, the currently reported chemistries and mechanisms for the catalytic conversion of polysulfides are presented in detail. Subsequently, the rational design of polysulfide catalytic materials from catalytic polymers and frameworks to active sites loaded carbons for polysulfide catalysis to accelerate the reaction kinetics is comprehensively discussed. Current breakthroughs are highlighted and directions to guide future primary challenges, perspectives, and innovations are identified. Computational methods serve an ever-increasing part in pushing forward the active center design. In summary, a cutting-edge understanding to engineer different polysulfide catalysts is provided, and both experimental and theoretical guidance for optimizing future MâS batteries and many related battery systems are offered
Polysulfide Catalytic Materials for FastâKinetic MetalâSulfur Batteries: Principles and Active Centers
Benefiting from the merits of low cost, ultrahighâenergy densities, and environmentally friendliness, metalâsulfur batteries (MâS batteries) have drawn massive attention recently. However, their practical utilization is impeded by the shuttle effect and slow redox process of polysulfide. To solve these problems, enormous creative approaches have been employed to engineer new electrocatalytic materials to relieve the shuttle effect and promote the catalytic kinetics of polysulfides. In this review, recent advances on designing principles and active centers for polysulfide catalytic materials are systematically summarized. At first, the currently reported chemistries and mechanisms for the catalytic conversion of polysulfides are presented in detail. Subsequently, the rational design of polysulfide catalytic materials from catalytic polymers and frameworks to active sites loaded carbons for polysulfide catalysis to accelerate the reaction kinetics is comprehensively discussed. Current breakthroughs are highlighted and directions to guide future primary challenges, perspectives, and innovations are identified. Computational methods serve an everâincreasing part in pushing forward the active center design. In summary, a cuttingâedge understanding to engineer different polysulfide catalysts is provided, and both experimental and theoretical guidance for optimizing future MâS batteries and many related battery systems are offered.DFG, 449814841, Organisch-Polyoxometallat-Co-Kristall-abgeleitete mesoporöse Metallcarbide/-nitride fĂŒr die Wasserstofferzeugung aus Meerwasse
Physiological parameters analysis of transfemoral amputees with different prosthetic knees
Physiological parameters analysis allows for a precise quantification of energy expenditure of transfemoral amputees with
different prosthetic knees. Comparative physiological parameters analysis that indicate the functional characteristics of knee joints is
essential to the choice of transfemoral amputee. The aim of this study was to propose a microprocessor-controlled prosthetic knee
(i-KNEE) and conducted physiological parameters (energy cost, gait efficiency and relative exercise intensity) comparison of transfemoral amputees with C-leg, Rheo Knee and Mauch under different walking speeds. MethodsË A microprocessor-controlled prosthetic knee
with hydraulic damper (i-KNEE) was developed. A two-factor repeated measurement experiment design was used. Each subject was
instructed to accept the same treatments. The two factors were type of prosthetic knees (the i-KNEE, the C-Leg, the Rheo Knee and the
Mauch) and speed (0.5, 0.7, 0.9, 1.1, 1.3 m/s). The energy cost, gait efficiency and relative exercise intensity of ten transfemoral amputees were measured. ResultsË For all the prosthetic knees, the energy cost increased along with walking speed. There was no significant
difference between three microprocessor-controlled prosthetic knees in energy cost. The gait efficiency of Mauch was always less than or
equal to other three microprocessor-controlled prosthetic knees in specific walking speed. The relative exercise intensity increased with
speed for all the prosthetic knees. More effort was needed for the transfemoral amputees with Mauch than other three microprocessorcontrolled prosthetic knees in the same walking speed. ConclusionsË The use of the microprocessor-controlled knee joints resulted in
reduced energy cost, improved gait efficiency and smaller relative exercise intensity
Structures, properties, and challenges of emerging 2D materials in bioelectronics and biosensors
Bioelectronics are powerful tools for monitoring and stimulating biological and biochemical processes, with applications ranging from neural interface simulation to biosensing. The increasing demand for bioelectronics has greatly promoted the development of new nanomaterials as detection platforms. Recently, owing to their ultrathin structures and excellent physicochemical properties, emerging two-dimensional (2D) materials have become one of the most researched areas in the fields of bioelectronics and biosensors. In this timely review, the physicochemical structures of the most representative emerging 2D materials and the design of their nanostructures for engineering high-performance bioelectronic and biosensing devices are presented. We focus on the structural optimization of emerging 2D material-based composites to achieve better regulation for enhancing the performance of bioelectronics. Subsequently, the recent developments of emerging 2D materials in bioelectronics, such as neural interface simulation, biomolecular/biomarker detection, and skin sensors are discussed thoroughly. Finally, we provide conclusive views on the current challenges and future perspectives on utilizing emerging 2D materials and their composites for bioelectronics and biosensors. This review will offer important guidance in designing and applying emerging 2D materials in bioelectronics, thus further promoting their prospects in a wide biomedical field
Development and Evaluation of a Rehabilitation Wheelchair with Multiposture Transformation and Smart Control
Stroke and other neurological disorders have an effect on mobility which has a significant impact on independence and quality of life. The core rehabilitation requirements for patients with lower limb motor dysfunction are gait training, restand, and mobility. In this work, we introduce a newly developed multifunctional wheelchair that we call âReChairâ and evaluated its performance preliminarily. ReChair seamlessly integrates the mobility, gait training, and multiposture transformation. ReChair driving and multiposture transformation are done using the voice, button, and mobile terminal control. This work describes the functional requirements, mechanical structure, and control system and the overall evaluation of ReChair including the kinematic simulation of the multiposture transformation and passive lower limb rehabilitation training to quantitatively verify the motion capability of ReChair, the voice control system evaluation that shows how the voice recognition system is suitable for home environment, the sensorless speed detection test results that indicate how the wheel speeds measured by sensorless method are appropriate for travelling control, and the passive and balance training test results that show how the lower limb rehabilitation training in daily life by ReChair is convenient. Finally, the experimental results show that ReChair meets the patientsâ requirements and has practical significance. It is cost-effective, easy to use, and supports multiple control modes to adapt to different rehabilitation phases
Functionalized poly(arylene ether sulfone) containing hydroxyl units for the fabrication of durable, superhydrophobic oil/water separation membranes
The stability of superhydrophobicity is crucial for the long-term application of an oil/water separation membrane in harsh environments such as high temperatures and various aggressive solvents. However, achieving such a stable superhydrophobic membrane remains a challenge. In this study, high performance fibrous oil/water separation membranes with a highly stable superhydrophobicity were fabricated by designing a functional polymer containing hydroxyl units. The reaction of hydroxy groups in poly(arylene ether sulfone) with octadecyltrichlorosilane (OTS) produces stable covalent interactions, which greatly enhance the stability of OTS on the PAES-OH (polyarylene ether sulfone containing hydroxy units) fibrous membrane fabricated by electrospinning, thus improving the stability of superhydrophobicity of the membrane. The stability of the OTS layer was characterized by FT-IR, SEM and water contact angle measurement. The results suggest that OTS is highly stable on a PAES-OH membrane, while OTS on a polyethersulfone (PES) fibrous membrane is detached from the fiber during ultrasonic cleaning. The obtained membrane is superhydrophobic, with a water contact angle (CA) as high as 159.2° and a threshold sliding angle (TSA) as low as 7.8° even after ultrasonic cleaning for 3 h. In addition, the oil/water separation experiments indicate that this membrane has an excellent performance in the separation of oil from oil/water mixtures, and oil/water emulsions: the gravity driven flux is 7260-8720 L (m2 h)-1 and the water rejection is over 99%. This study provides a new approach for fabricating oil/water separation membranes with highly stable superhydrophobic properties from the perspective of designing new polymers.status: publishe