Magnesium alloys with excellent degradability and biocompatibility are promising materials for biomedical implants,saving patients the burden of second ***,their mechanical properties and corrosion resistance are sign...
详细信息
Magnesium alloys with excellent degradability and biocompatibility are promising materials for biomedical implants,saving patients the burden of second ***,their mechanical properties and corrosion resistance are significantly below the requirements for implant *** study aims to improve the mechanical and corrosion resistance properties of Mg-3Zn-0.2Ca alloy by pre-torsion treatment,and find out the optimal shear *** rod-shaped Mg-3Zn-0.2Ca alloy specimens were pre-torsion treated at different torsion *** effect of free-end torsion on Mg-3Zn-0.2Ca alloy was characterized through microstructure analysis,mechanical testing,and corrosion ***-torsion treatment can refine grain and induce twins and dislocations in Mg-3Zn-0.2Ca *** surface hardness increases with the increase in torsion *** yield strength and ultimate strength initially increase and then decrease with increasing torsion angle,while ductility decreases with increasing torsion *** with a shear strain of 30%exhibit the highest tensile strength,reaching 284.78±10.62 MPa,with an elongation of 19.37±1.66%.Furthermore,they show a significant improvement in fatigue lives both before and after *** the stress amplitude is 120 MPa,the fatigue lives for specimens without pre-torsion treatment are 54,275 cycles and 4324 cycles before and after pre-corrosion,while they increased significantly to 92,015 cycles and 5050 cycles with the 30%shear strain,***,the 30%shear strain specimens show a significant reduction in corrosion *** conclusion,pre-torsion treatment can effectively modify the microstructure of Mg-3Zn-0.2Ca alloy,enhancing both mechanical properties and corrosion *** optimal shear strain for this improvement is 30%.This study provides a practical method to enhance the mechanical properties and corrosion resistance of Mg-3Zn-0.2Ca alloy,making it more suitable for biomedical implan
The supernumerary robotic limb (SRL) mounted on the shoulder has been demonstrated to be able to serve as a third arm to assist human in overhead support task. However, the mechanical connection between the wearer and...
详细信息
The supernumerary robotic limb (SRL) mounted on the shoulder has been demonstrated to be able to serve as a third arm to assist human in overhead support task. However, the mechanical connection between the wearer and the SRL means that human operator's movement will continually disturb the SRL and may lead to instability. Moreover, there may be physical conflicts between SRL and human operator due to their different intentions, which may potentially increase the load on human operator. Therefore, it's necessary to control SRL to ensure stable supporting and transparent interaction. Here, we propose an adaptive controller for human movement compensation. Firstly, we model the human-SRL coordinative behavior based on non-zero-sum differential game theory aiming to enhance the support stability and reduce the operator's load, which is a framework capable of dynamically regulating the control strategies between two interacting agents. We then implement an adaptive control strategy that adjusts the SRL's input optimally responsive to the human operator's input in the sense of Nash equilibrium to meet predefined control objectives. From experimental results during overhead support task, the proposed controller reduces the peak reaction force from 15.59 N to 4.50 N compared to the state-of-the-art controller that disregards human input while ensuring the stability of support, thereby providing advantage for human-SRL coordination in overhead support task. Note to Practitioners - To ensure optimal overhead assistance, the stability of the support and the safety of the human operator are of paramount importance. Therefore, this study investigates how to provide stable support and transparent interaction through movement compensation. Previous compensation methods lacked the understanding for the wearer and the optimal adjustment for the control of SRL. Consequently, this paper proposes a non-zero-sum differential game to model the desired behaviors between human operator an
Thee-vote is regarded as a waytoexpress the opinion that the voters ask for. Actually, the e-vote could be applied wildly likequestionnaire,***,thecoexistences of efficiency and security as well as transparency and pr...
详细信息
Oxide materials with a non-centrosymmetric structure exhibit bulk photovoltaic effect(BPVE)but with a low cell *** the past few years,relatively larger BPVE coefficients have been reported for two-dimensional(2D)layer...
详细信息
Oxide materials with a non-centrosymmetric structure exhibit bulk photovoltaic effect(BPVE)but with a low cell *** the past few years,relatively larger BPVE coefficients have been reported for two-dimensional(2D)layers and stacks with asymmety-induced spontaneous ***,we report a crucial breakthrough in boosting the BPVE in 3R-MoS2 by adopting edge contact(EC)geometry using bismuth semimetal *** clear contrast to the typically used top contact(TC)geometry,the EC metal which strongly adheres to the edges and the subtrates can induce a pronounced tensile strain to the 3R-MoS2,and the lateral contact geometry allows to completely access to in-plane polarization from underneath layers reachable by light,leading to>100 times of BPVE enhancement in *** further design a 3R-MoS2/WSe2 heterojunction to demonstrate constructive coupling of BPVE with the conventional photovoltaic effect,indicating their potential in photodetectors and photovoltaic devices.
Thermal infrared remote sensors provide cost-effective and widespread land surface temperatures (LSTs) but often with spatiotemporal gaps due to discrete sampling and synoptic disturbance, greatly limiting their relia...
详细信息
Thermal infrared remote sensors provide cost-effective and widespread land surface temperatures (LSTs) but often with spatiotemporal gaps due to discrete sampling and synoptic disturbance, greatly limiting their reliability and application. Current gap-filling methods have been primarily developed and validated for medium- to low-resolution LSTs;however, with rising demand for spatiotemporally continuous, high-resolution (tens of meters like Landsat) LSTs across disciplines, there is an urgent need to assess these methods’ applicability and uncertainty at higher spatial resolutions under a unified framework. In this study, we apply eight typical and hybrid methods, including temporal interpolation, spatiotemporal interpolation, weight-based fusion, learning-based fusion, and four standard annual temperature cycle (ATC)-based hybrid reconstructions, to fill gaps in irregularly spaced Landsat series over Weishan, Huairou, and Yulin, China. These sites represent cropland in a sub-humid plain, forest in a sub-humid mountain region, and grassland in the semi-arid Loess Plateau. We evaluate their performance in terms of spatiotemporal pattern, statistical accuracy, sensitivity to input data quality and distribution, and adaptability to different synoptic and surface conditions based on cloudy Landsat data and in-situ measurements. Results reveal that the enhanced ATC (EATC) method is optimal among these methods, capturing all-weather spatiotemporal dynamics at the Landsat scale with superior accuracy and robustness under various input, cloud, and ground conditions. In addition, the ATC-based hybrid methods do not necessarily improve the statistical accuracy over their respective typical ones. This comprehensive evaluation provides valuable insights into the selection of appropriate gap-filling methods for generating Landsat-like LSTs under all-weather conditions and highlights the need for further advancements especially in addressing abrupt changes in land cover types an
In Weighted Model Counting(WMC),we assign weights to literals and compute the sum of the weights of the models of a given propositional formula where the weight of an assignment is the product of the weights of its **...
详细信息
In Weighted Model Counting(WMC),we assign weights to literals and compute the sum of the weights of the models of a given propositional formula where the weight of an assignment is the product of the weights of its *** current WMC solvers work on Conjunctive Normal Form(CNF)***,CNF is not a natural representation for human-being in many *** by the stronger expressive power of Pseudo-Boolean(PB)formulas than CNF,we propose to perform WMC on PB *** on a recent dynamic programming algorithm framework called ADDMC for WMC,we implement a weighted PB counting tool *** compare PBCounter with the state-of-the-art weighted model counters SharpSAT-TD,ExactMC,D4,and ADDMC,where the latter tools work on CNF with encoding methods that convert PB constraints into a CNF *** experiments on three domains of benchmarks show that PBCounter is superior to the model counters on CNF formulas.
Game theory-based models and design tools have gained substantial prominence for controlling and optimizing behavior within distributed engineeringsystems due to the inherent distribution of decisions among individua...
详细信息
Laser-based light sources are highly desirable for display applications due to their narrow emission linewidth and exceptional ***,the coherence inherent in lasers often leads to the formation of unwanted speckles,whi...
详细信息
Laser-based light sources are highly desirable for display applications due to their narrow emission linewidth and exceptional ***,the coherence inherent in lasers often leads to the formation of unwanted speckles,which can significantly degrade display ***,there is a critical need for light sources that retain the narrow emission and high brightness of lasers while minimizing spatial coherence to reduce speckle *** lasing has emerged as a promising strategy to address this issue,though its random emission directions can lead to energy *** overcome this challenge,we propose a novel approach in which CdSe nanoplatelets,known for their efficient optical gain properties,are self-assembled into supraparticles(SPs),serving as both scattering centers and gain *** configuration enables random lasing,and by coupling the random gain medium to a Fabry-Perot(FP)cavity,we successfully direct the typically omnidirectional random lasing into a controlled,low-coherence *** experimental results,comparing conventional lasers(e.g.,He:Ne lasers)with our SP-based laser for a projector,demonstrate effective suppression of speckle formation,reducing speckle contrast from 0.5 to *** findings offer a promising solution for improving the performance and quality of laser-based displays.
Semantic segmentation of urban remote sensing images (URSIs) is crucial for the development of smart cities and the acceleration of urban information. In view of the characteristics of URSIs with intricate backgrounds...
详细信息
Deep Learning image forgery localization methods have achieved remarkable results but cannot maintain comparable performance when the forgery images are JPEG compressed, a format that is widely used in daily informati...
详细信息
暂无评论