Traditional noble metal‐based catalysts for glucose sensing usually suffer from easy deactivation by halides and weak sensing properties. To unravel these limits, herein, a novel nature‐inspired ...design concept (mimicking a “rock–soil–grass” geotexture system) is purposed to build a free‐standing hierarchical micro‐nano architecture. Thanks to the design (rigid and conductive Ni foam) (“rock”, underlayer, rough and highly disordered graphene nanosheets (GNSs) (“soil”, middle‐layer), and strong catalytic activity of multiscale grass‐like Co3O4 (“grass”, top‐layer), the bionic structure achieves ultra‐high sensitivity, a low limit of detection (120 × 10−9 m), an extremely short response time, broad linear ranges (two stages: 1–10 000 and 10 000–30 040 µm), good anti‐Cl−‐poisoning and anti‐interference properties, and long‐term stability. Besides the structural design, the “gotong‐royong” effects (the strong interface coupling and charge transfer between GNSs and Co3O4 and energetically favorable glucose adsorption on Co3O4) also contribute to the high sensing properties, as verified by kinetic studies and density functional theory simulation. To determine human blood glucose levels, the self‐made glucometer with the self‐developed software demonstrates an ultra‐high recovery rate (99.0–100.9%), validating the potential for high‐performance blood‐glucose sensing.
A novel nature‐inspired design concept (mimicking a “rock–soil–grass” geotexture system) is purposed to build a free‐standing hierarchical micro‐nano architecture. Thanks to the design and “gotong‐royong” effects, the bionic structure achieves a superb glucose sensing property and stability. The self‐made glucometer with the self‐developed software demonstrates an ultra‐high recovery rate, validating the potential for high‐performance blood‐glucose sensing.
Abstract
The ±1100kV high voltage capacitor filled SF6 gas bushing is an important equipment to realize the electrical connection between the converter transformer and the valve tower. The paper ...mainly discusses the design of the external and internal insulation structure. The research content is divided into four parts, the actual operating environment and the characteristics of the voltage and current waveform of converter transformer bushing are discussed. The design and analysis of the hollow composite insulator, corona ring and tail end of the bushing have been done. The main insulation structure of bushing has been designed by the equal margin method, and simulation and analysis of the multi-physical field have been done. The three dimensional electric field simulation model has been set up to calculate and analyze the external insulation performance of the bushing. The results show that the main insulation of the bushing is fit to the capacitance structure, the maximum axial field strength of the bushing is 0.62kV·mm
−1
, and the end of the bushing should be equipped with apple type corona ring. The insulation distance of the hollow composite insulator is designed as 7490mm. The insulation distance of the bushing tail is designed as 3110mm. In the actual operating environment, the maximum field strength of the corona ring appears on the lower end surface, and the value is 2386V·mm
−1
. The results of the paper can provide the theoretical basis for the design of the external insulation of the converter transformer bushing used in the HVDC transmission project.
Quality of experience (QoE) measures the overall perceived quality of mobile video delivery from subjective user experience and objective system performance. Current QoE prediction models have two ...main limitations: (1) insufficient consideration of the factors influencing QoE, and (2) limited studies on QoE models for acceptability prediction. In this paper, a set of novel acceptability-based QoE models, denoted as A-QoE, is proposed based on the results of comprehensive user studies on subjective quality acceptance assessments. The models are able to predict users' acceptability and pleasantness in various mobile video usage scenarios. Statistical nonlinear regression analysis has been used to build the models with a group of influencing factors as independent predictors, which include encoding parameters and bitrate, video content characteristics, and mobile device display resolution. The performance of the proposed A-QoE models has been compared with three well-known objective Video Quality Assessment metrics: PSNR, SSIM and VQM. The proposed A-QoE models have high prediction accuracy and usage flexibility. Future user-centred mobile video delivery systems can benefit from applying the proposed QoE-based management to optimize video coding and quality delivery strategies.
The 2019 coronavirus disease (COVID-19) outbreak has put the global health system under the spotlight. As part of the medical workforce, nurses play an important role in interacting with and caring ...for patients; hence, patient-centered communication (PCC) has been emphasized in nursing education. Thus, it is worth investigating how future nurses perceive PCC and PCC-related factors under the special circumstances of COVID-19. For this purpose, the present study analyzed the mechanisms underlying the association between self-efficacy and nurse-patient communication tendency through learning burnout among nursing students during the COVID-19 pandemic.
The general self-efficacy questionnaire, college students' learning burnout scale, and doctor-patient communication tendency scale were used to survey 2,231 nursing students in higher vocational medical colleges at the onset of the COVID-19 pandemic.
General self-efficacy can directly negatively correlate with the degree of nursing students' overall nurse-patient communication, including caring, sharing, and health promotion. Dejection from learning burnout partially mediated the relationships between self-efficacy and caring and between self-efficacy and sharing; it fully mediated the relationship between self-efficacy and health promotion. Reduced personal accomplishment partially mediated between self-efficacy and caring, while it fully mediated between self-efficacy and health promotion; however, it did not play a role in the sharing model.
Self-efficacy influences nurse-patient communication through learning burnout. Specifically, dejection and reduced personal accomplishment-two aspects of learning burnout-may compromise nursing students' willingness to engage in PCC. Thus, the importance of PCC, especially during critical health situations such as pandemics, should be emphasized further in future nursing education.
Quantitative analysis of phosphate anions was achieved by measurement of "turn-off" SERS based on the first-layer effect of a chemical mechanism. More importantly, our results demonstrate that it is ...possible, by means of semiconductor-enhanced Raman scattering, to enhance the SERS sensing performance including stability and reproducibility.
Molecular dynamics method is used to investigate the dynamic response of void-included aluminum under three loading patterns, which are constant strain rate, constant-stress Hugoniostat and direct ...shock loadings. The simulations show a very weak dependence of the dynamic response on the loading patterns under weak loadings, where appears a similar dislocation distribution originated from the initial void. When the pressure exceeds 13.3 GPa, the homogeneous dislocations will appear for the direct shock loading, whose growth can lead to intersections and then hinders the relaxation of the shear stress to some extent. Besides, we also observe the transformation from FCC to HCP when the loading pressure exceeds 33.5 GPa, whose effect on the shear stress is very significant. For the other two loadings, the dislocations still firstly originate from the void and then grow into symmetrical dislocation bands along the {111} planes, whose effect on the shear stress is not significant. Finally, we provide the adjusted parameter (damping coefficient of stress) for the constant-stress Hugoniostat method with a wide range of shock pressure, which can agree with the results from the direct shock for the void-included sample. These results are important reference for the application of the constant-stress Hugoniostat method in defective metals.
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•Liquid gallium is firstly used as the negative electrode for Al-ion batteries.•The Al storage mechanism, i.e., the reversible alloying/dealloying, has been demonstrated.•This liquid ...Ga negative electrode shows no dendrite and no corrosion merits during repeated cycling.•No pulverization problem appears after long-term cycling.•This liquid Ga negative electrode is recyclable.
Although rechargeable Al batteries attract interests due to their features of abundant Al source and high safety, the Al negative electrodes suffer from critical problems, including dendrite, corrosion, pulverization, non-recyclable Al wastes, etc. For addressing these challenges, here a novel liquid gallium is demonstrated for negative electrodes of Al batteries. The results show that the liquid gallium negative electrode enables the reversible alloying/dealloying between Al and Ga. Remarkably, the essential problems in the solid Al negative electrodes, including dendrite, corrosion and pulverization, would be well avoided attributed to the liquid state of the Ga electrode during cycling. In addition to the enhanced stable cycling performance, Ga negative electrode is also recyclable, allowing the cycled Ga for further presenting stable cycling in the re-assembled batteries, and which is helpful for its practical application. The results in the present work open a precedent way to develop the advanced negative electrode with dendrite-free, corrosion resistant and recyclable features and advantages for various types of rechargeable batteries.
Calendering is an essential step in the manufacturing process of lithium-ion batteries. However, the intrusion of active particles into metal foil can damage the current collector during calendering. ...Here, we investigate the changes in surface morphology and the tensile properties of current collector after calendering. The damage mechanisms of tensile strength reduction for current collector due to compressive pressure are revealed by combining the calendering tests, tensile experiments, and simulations. Specifically, the DEM-FEM scheme is proposed, which combines the discrete element method (DEM) with the finite element method (FEM) to characterize the mechanical behavior of current collectors after the intrusion of active particles. The results show that the current collectors become more brittle and vulnerable with the increase of compressive pressure. Finally, the failure phase diagrams are presented during the winding and electrochemical processes. This study can reveal the failure behavior of current collectors and guides the electrode manufacturing optimization.
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•A computational framework is developed for active particles pressed into the foil.•The evolution of surface morphology and mechanical properties of the current collector is revealed during calendering.•The effect of calendering pressure on current collectors is introduced into the winding process to optimize manufacturing.
A
bstract
We study a toy model of the Kerr/CFT correspondence using string theory on AdS
3
×
S
3
. We propose a single trace irrelevant deformation of the dual CFT generated by a vertex operator with ...spacetime dimensions (2
,
1). This operator shares the same quantum numbers as the integrable
$$ T\overline{J} $$
T
J
¯
deformation of two-dimensional CFTs where
$$ \overline{J} $$
J
¯
is a chiral U(1) current. We show that the deformation is marginal on the worldsheet and that the target spacetime is deformed to null warped AdS
3
upon dimensional reduction. We also calculate the spectrum of the deformed theory on the cylinder and compare it to the field theory analysis of
$$ T\overline{J} $$
T
J
¯
-deformed CFTs.
Internal short circuit in lithium-ion batteries is a crucial hazard threatening. It is accurately difficult to monitor the internal signals in time of the lithium-ion batteries during the process of ...internal short circuit. Herein, a novel method is developed to monitor multiple signal evolution behaviour using a sealed tank and sensors. The internal signals of LFP batteries and NMC batteries exhibit different evolution behaviours, especially in the response sequence of pressure and gas. Battery capacity has an impact on ISC signal response sequence and time for LFP batteries, showing identical sequence and shorter time with the increase of capacity. The voltage and temperature are considered as sensitive signals for both LFP and NMC811 batteries that sensitive signals are defined based on their response speed. This operando technique provides a suitable platform for understanding the side reaction mechanism during thermal runaway in commercial LIBs.
•A novel in-situ method was developed for internal short circuit measurement.•ISC behaviour of LFP and NMC811 batteries was investigated.•Battery capacity has an impact on ISC evolution behaviour for LFP batteries.•Established sensitive signals for internal short circuit in LFP and NMC811 batteries.
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