A dynamic particle swarm optimization with learning strategy (DPSO-LS) is proposed for key parameter estimation for permanent magnet synchronous machines (PMSMs), where the voltage-source inverter ...(VSI) nonlinearities are taken into account in the parameter estimation model and can be estimated simultaneously with other machine parameters. In the DPSO-LS algorithm, a novel movement modification equation with variable exploration vector is designed to effectively update particles, enabling swarms to cover large areas of search space with large probability and thus the global search ability is enhanced. Moreover, a Gaussian-distribution-based dynamic opposition-based learning strategy is developed to help the pBest jump out local optima. The proposed DPSO-LS can significantly enhance the estimator model accuracy and dynamic performance. Finally, the proposed algorithm is applied to multiple parameter estimation including the VSI nonlinearities of a PMSM. The performance of DPSO-LS is compared with several existing PSO algorithms, and the comparison results show that the proposed parameters estimation method has better performance in tracking the variation of machine parameters effectively and estimating the VSI nonlinearities under different operation conditions.
The urgent need for ecofriendly, stable, long‐lifetime power sources is driving the booming market for miniaturized and integrated electronics, including wearable and medical implantable devices. ...Flexible thermoelectric materials and devices are receiving increasing attention, due to their capability to convert heat into electricity directly by conformably attaching them onto heat sources. Polymer‐based flexible thermoelectric materials are particularly fascinating because of their intrinsic flexibility, affordability, and low toxicity. There are other promising alternatives including inorganic‐based flexible thermoelectrics that have high energy‐conversion efficiency, large power output, and stability at relatively high temperature. Herein, the state‐of‐the‐art in the development of flexible thermoelectric materials and devices is summarized, including exploring the fundamentals behind the performance of flexible thermoelectric materials and devices by relating materials chemistry and physics to properties. By taking insights from carrier and phonon transport, the limitations of high‐performance flexible thermoelectric materials and the underlying mechanisms associated with each optimization strategy are highlighted. Finally, the remaining challenges in flexible thermoelectric materials are discussed in conclusion, and suggestions and a framework to guide future development are provided, which may pave the way for a bright future for flexible thermoelectric devices in the energy market.
A comprehensive exploration of the material design strategies, processing methods, and underlying physics and chemistry behind the enhanced thermoelectric properties of flexible thermoelectric materials is presented, emphasizing innovative approaches and suggesting future pathways for the development of a new generation of wearable electronics.
The long-standing popularity of thermoelectric materials has contributed to the creation of various thermoelectric devices and stimulated the development of strategies to improve their thermoelectric ...performance. In this review, we aim to comprehensively summarize the state-of-the-art strategies for the realization of high-performance thermoelectric materials and devices by establishing the links between synthesis, structural characteristics, properties, underlying chemistry and physics, including structural design (point defects, dislocations, interfaces, inclusions, and pores), multidimensional design (quantum dots/wires, nanoparticles, nanowires, nano- or microbelts, few-layered nanosheets, nano- or microplates, thin films, single crystals, and polycrystalline bulks), and advanced device design (thermoelectric modules, miniature generators and coolers, and flexible thermoelectric generators). The outline of each strategy starts with a concise presentation of their fundamentals and carefully selected examples. In the end, we point out the controversies, challenges, and outlooks toward the future development of thermoelectric materials and devices. Overall, this review will serve to help materials scientists, chemists, and physicists, particularly students and young researchers, in selecting suitable strategies for the improvement of thermoelectrics and potentially other relevant energy conversion technologies.
As an extended member of the thermoelectric family, ionic thermoelectrics (i‐TEs) exhibit exceptional Seebeck coefficients and applicable power factors, and as a result have triggered intensive ...interest as a promising energy conversion technique to harvest and exploit low‐grade waste heat (<130 °C). The last decade has witnessed great progress in i‐TE materials and devices; however, there are ongoing disputes about the inherent fundamentals and working mechanisms of i‐TEs, and a comprehensive overview of this field is required urgently. In this review, the prominent i‐TE effects, which set the ground for i‐TE materials, or more precisely, thermo‐electrochemical systems, are first elaborated. Then, TE performance, capacitance capability, and mechanical properties of such system‐based i‐TE materials, followed by a critical discussion on how to manipulate these factors toward a higher figure‐of‐merit, are examined. After that, the prevalent molding methods for assembling i‐TE materials into applicable devices are summarized. To conclude, several evaluation criteria for i‐TE devices are proposed to quantitatively illustrate the promise of practical applications. It is therefore clarified that, if the recent trend of developing i‐TEs can continue, the waste heat recycling landscape will be significantly altered.
In this review, the progress in ionic thermoelectrics, including fundamental theories, material designations, property characteristics, performance regulations, molding methodologies, and device employments, are comprehensively summarized. Perspective remarks on the outlook and challenges of ionic thermoelectrics are also discussed.
The study of cost‐efficient and high‐performance electrocatalysts for oxygen evolution reaction (OER) has attracted much attention. Here, porous microrod arrays constructed by carbon‐confined ...NiCo@NiCoO2 core@shell nanoparticles (NiCo@NiCoO2/C PMRAs) are fabricated by the reductive carbonization of bimetallic (Ni, Co) metal–organic framework microrod arrays (denoted as NiCo‐MOF MRAs) and subsequent controlled oxidative calcination. They successfully combine the desired merits including large specific surface areas, high conductivity, and multiple electrocatalytic active sites for OER. In addition, the oxygen vacancies in NiCo@NiCoO2/C PMRAs significantly improve the conductivity of NiCoO2 and accelerate the kinetics of OER. The above advantages obviously enhance the electrocatalytic performance of NiCo@NiCoO2/C PMRAs. The experimental results demonstrate that the NiCo@NiCoO2/C PMRAs as electrocatalysts exhibit high catalytic activity, low overpotential, and high stability for OER in alkaline media. The strategy reported will open up a new route for the fabrication of porous bimetallic composite electrocatalysts derived from MOFs with controllable morphology for electrochemical energy conversion devices.
Porous microrod arrays (PMRAs) constructed by carbon‐confined NiCo@NiCoO2 core@shell nanoparticles (NiCo@NiCoO2/C PMRAs) are designed and successfully fabricated by the reductive carbonization of bimetallic metal–organic frameworks and subsequent controlled oxidative calcinations in air. They exhibit superior electrocatalytic activity, low overpotential, and high stability for the oxygen evolution reaction in alkaline media.
Driven by the intensive efforts in the development of high‐performance GeTe thermoelectrics for mass‐market application in power generation and refrigeration, GeTe‐based materials display a high ...figure of merit of >2.0 and an energy conversion efficiency beyond 10%. However, a comprehensive review on GeTe, from fundamentals to devices, is still needed. In this regard, the latest progress on the state‐of‐the‐art GeTe is timely reviewed. The phase transition, intrinsic high carrier concentration, and multiple band edges of GeTe are fundamentally analyzed from the perspectives of the native atomic orbital, chemical bonding, and lattice defects. Then, the fabrication methods are summarized with a focus on large‐scale production. Afterward, the strategies for enhancing electronic transports of GeTe by energy filtering effect, resonance doping, band convergence, and Rashba band splitting, and the methods for strengthening phonon scatterings via nanoprecipitates, planar vacancies, and superlattices, are comprehensively reviewed. Besides, the device assembly and performance are highlighted. In the end, future research directions are concluded and proposed, which enlighten the development of broader thermoelectric materials.
The phase transition, multiple valence bands, and resonant bonding endow GeTe with promising thermoelectric performance. Significant breakthroughs are achieved in GeTe‐based materials. This review summarizes the recent progress in developing high‐performance GeTe‐based materials and devices, including the underlying fundamentals, large‐scale production, novel strategies for boosting performance, and techniques of device assembly.
Owing to their capabilities of solid-state conversion between heat and electricity, zero-emission, and high flexibility, flexible thermoelectric devices (F-TEDs) have exhibited great application ...possibilities for both portable power generation and localized refrigeration. However, with the rapid development of thermoelectric science and technology, there is still a lack of comprehensive review on the rational design of F-TEDs from the fundamentals to structures, which critically determines the performance and conformality of F-TEDs. To address this issue, here, we timely overview the latest progress on the up-to-the-date F-TEDs with their unique designs. We carefully summarize the structure-related principles and factors that determine the performance of F-TEDs and the advanced strategies for improving their utilities. Besides, we focus on the timeliest designs for the inorganic-based devices, organic-based devices, and hybrid-based devices targeting both power generation and refrigeration. In the end, we point out the current challenges, controversies, and prospects of F-TEDs.
Regulatory T cells (Tregs) and plasmacytoid dendritic cells (pDCs) play important roles in the immune escape of cancer. In this study, we investigated pDCs and pDC‐induced inducible costimulator ...(ICOS)+ Treg populations in peripheral blood from gastric cancer (GC) patients and healthy donors by flow cytometry. The distribution of these cells in carcinoma tissue, peritumor tissue, and normal gastric mucosa was detected by immunohistochemistry. Plasma and tissue concentration of the cytokines such as interleukin‐10 and transforming growth factor‐β1 were also measured. We found that the numbers of pDCs, Tregs, and ICOS+ Tregs in peripheral blood were increased in GC patients compared with healthy donors. In tissue, Tregs and ICOS+ Tregs were found distributing mainly in carcinoma tissue, whereas pDCs were mainly found in peritumor tissue. Moreover, the Foxp3+ICOS+/Foxp3+ cell ratio in carcinoma and peritumor tissue were higher than that in normal tissue. There were more ICOS+ Tregs in tumor and peritumor tissue of late‐stage GC patients. There was a positive correlation between pDCs and ICOS+ Tregs in peripheral blood and peritumor tissue from GC patients. In conclusion, pDCs may play a potential role in recruiting ICOS+ Tregs, and both participate in the immunosuppression microenvironment of GC.
We found that numbers of pDCs, Tregs and ICOS+ Tregs in peripheral blood were increased in GC patients compared with healthy donors. In tissue, Tregs and ICOS+ Tregs were found distributing mainly in carcinoma tissue, while pDCs mainly in peritumor tissue. Both pDCs and ICOS+ Tregs participate in the immunosuppression microenviroment of gastric cancer together.
Owing to the sustainability, environmental friendliness, and structural diversity of biomass‐derived materials, extensive efforts have been devoted to use them as energy storage materials in ...high‐energy rechargeable batteries. A timely and comprehensive review from the structures to mechanisms will significantly widen this research field. Here, it starts with the operation mechanism of batteries, and it aims to summarize the latest advances for biomass‐derived carbon to achieve high‐energy battery materials, including activation carbon methods and the structural classification of biomass‐derived carbon materials from zero dimension, one dimension, two dimension, and three dimension. Each strategy starts with carefully selected examples and then moves to illustrate the underlying transport mechanism of electrons in the structure. In the end, challenges, strategies, and outlooks are pointed out for the future development of biomass‐derived carbon materials. Overall, this review will help researchers choose appropriate strategies to design biomass‐derived carbon materials, thereby promoting the application of biomass materials in battery design.
This review comprehensively summarizes the internal structure of biomass‐derived carbon materials, which aims to provide suitable environment‐friendly and low consumption green materials for high‐performance batteries design.
The ubiquitin‐proteasome system (UPS) is a complex process that regulates protein stability and activity by the sequential actions of E1, E2 and E3 enzymes to influence diverse aspects of eukaryotic ...cells. However, due to the diversity of proteins in cells, substrate selection is a highly critical part of the process. As a key player in UPS, E3 ubiquitin ligases recruit substrates for ubiquitination specifically. Among them, RING E3 ubiquitin ligases which are the most abundant E3 ubiquitin ligases contribute to diverse cellular processes. The multisubunit cullin‐RING ligases (CRLs) are the largest family of RING E3 ubiquitin ligases with tremendous plasticity in substrate specificity and regulate a vast array of cellular functions. The F‐box protein Skp2 is a component of CRL1 (the prototype of CRLs) which is expressed in many tissues and participates in multiple cellular functions such as cell proliferation, metabolism, and tumorigenesis by contributing to the ubiquitination and subsequent degradation of several specific tumor suppressors. Most importantly, Skp2 plays a pivotal role in a plethora of cancer‐associated signaling pathways. It enhances cell growth, accelerates cell cycle progression, promotes migration and invasion, and inhibits cell apoptosis among others. Hence, targeting Skp2 may represent a novel and attractive strategy for the treatment of different human cancers overexpressing this oncogene. In this review article, we summarized the known roles of Skp2 both in health and disease states in relation to the UPS.
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