bluuebunny/crossref_metadata_2025 huggingface dataset:
Tribology Properties of Titanium‐Based Metals Reinforced by BN Nanosheets
Authors: Ma Zeyu , Huang Ruoxuan , Kostyantyn Grinkevych , Wang Yun , Li Ruitao , Liu Zhenqiang , Xu Jiujun
Published: April 2021

Herein, the tribology properties of titanium matrix composites (TMCs) are studied, which are formed by simply blending of aspherical Ti particles and BN nanosheets (BNNSs) using low‐energy ball milling and then spark plasma sintering. The mechanical properties of TMCs are characterized by nanoindentation tests, and their friction and wear properties are determined by ball‐on‐disc tests. The results show that the TMC with 0.1 vol% BNNSs (0.1‐TMC) content has the highest hardness and the ratio of hardness to elastic modulus (H/E). In addition, the lowest coefficient of friction (COF) and wear loss of 0.1‐TMC indicate the best tribological performance. Analysis of the worn morphology reveals that the pure Ti with the lowest H/E value presents several microcracks on the surface, implying the microcutting dominates wear process. The addition of BNNSs effectively inhibits the formation of microcracks, thus improves the tribological properties. However, as the content increase, the adhesion of BNNSs and Ti powder becomes worse, increasing the wear debris, leading to abrasive wear and adhesive wear and causing the even more severe wear. As a result, the COF and wear loss of 0.8‐TMC are the largest.
Atomic Scale Structure Inspired 3D‐Printed Porous Structures with Tunable Mechanical Response
Authors: Ambekar Rushikesh S. , Mohanty Ipsita , Kishore Sharan , Das Rakesh , Pal Varinder , Kushwaha Brijesh , Roy Ajit K. , Kumar Kar Sujoy , Tiwary Chandra S.
Published: April 2021

To enhance the overall energy efficiency of the individual parts used in automobile and aerospace industries, study of the specific strength of the components becomes crucial. As a result, in the last couple of decades, large efforts have been made to develop porous architecture with light weight and high specific strength. Herein, an easily scalable and controlled processing of a stochastic bicontinuous atomic scale structure inspired complex porous architecture using 3D printing is demonstrated. The complex topology of the architecture provides enhanced mechanical properties (specific strength, modulus, specific energy absorption etc.). These properties can be easily tuned with the help of changing density and surface area. Based on experimental observations, an analytical model is proposed to correlate these properties with density. These individual architectures can be stacked on top of each other with different combinations to build hierarchical structures, which allows engineering of the directional dependency of the mechanical response.
Spray Pyrolysis‐Aerosol Deposition for the Production of Thick Yttria‐Stabilized Zirconia Coatings
Authors: Song Guanyu , Adamczyk Jesse , Park Yensil , Toberer Eric S. , Hogan Christopher J.
Published: April 2021

Aerosol deposition (AD) is a coating technique wherein particles are impacted onto a target substrate at reduced pressures, and supersonic particle impact velocities lead to coating consolidation. The limiting step in AD application is often not supersonic deposition operation, but aerosolization of powder particles with the proper size distribution; the translational impact velocity is strongly size‐dependent. It is demonstrated that by directly synthesizing particles in the gas phase, size‐controlled ceramic particles can be injected into AD systems. This in situ formation step obviates the need for particle aerosolization. Ultrasonic spray pyrolysis (USP) is applied to produce yttria‐stabilized zirconia (YSZ), and USP is directly coupled with AD to produce consolidated, thick, YSZ coatings on metal substrates. USP‐AD yields YSZ coatings on stainless steel and aluminum substrates with porosities <0.20, which grow to thicknesses beyond 100 μm. Aerodynamic particle spectrometry and electron microscopy reveal that the depositing particles are 200 nm–1.2 μm in diameter, though each particle is composed of nanocrystalline YSZ. Supporting computational fluid dynamics calculations demonstrate that the YSZ particle impact speeds are above 300 m s−1. Thermal conductivity measurements demonstrate that USP‐AD coatings have conductivities consistent with those produced from high‐temperature processes.
Non‐Volatile Electrolyte‐Gated Transistors Based on Graphdiyne/MoS2 with Robust Stability for Low‐Power Neuromorphic Computing and Logic‐In‐Memory
Authors: Yao Bin‐Wei , Li Jiaqiang , Chen Xu‐Dong , Yu Mei‐Xi , Zhang Zhi‐Cheng , Li Yuan , Lu Tong‐Bu , Zhang Jin
Published: April 2021

Artificial synapses are the key building blocks for low‐power neuromorphic computing that can go beyond the constraints of von Neumann architecture. In comparison with two‐terminal memristors and three‐terminal transistors with filament‐formation and charge‐trapping mechanisms, emerging electrolyte‐gated transistors (EGTs) have been demonstrated as a promising candidate for neuromorphic applications due to their prominent analog switching performance. Here, a novel graphdiyne (GDY)/MoS2‐based EGT is proposed, where an ion‐storage layer (GDY) is adopted to EGTs for the first time. Benefitting from this Li‐ion‐storage layer, the GDY/MoS2‐based EGT features a robust stability (variation < 1% for over 2000 cycles), an ultralow energy consumption (50 aJ µm−2), and long retention characteristics (>104 s). In addition, a quasi‐linear conductance update with low noise (1.3%), an ultrahigh Gmax/Gmin ratio (103), and an ultralow readout conductance (<10 nS) have been demonstrated by this device, enabling the implementation of the neuromorphic computing with near‐ideal accuracies. Moreover, the non‐volatile characteristics of the GDY/MoS2‐based EGT enable it to demonstrate logic‐in‐memory functions, which can execute logic processing and store logic results in a single device. These results highlight the potential of the GDY/MoS2‐based EGT for next‐generation low‐power electronics beyond von Neumann architecture.
In Situ Reconstruction of V‐Doped Ni2P Pre‐Catalysts with Tunable Electronic Structures for Water Oxidation
Authors: Zhao Tingwen , Shen Xiangjian , Wang Yuan , Hocking Rosalie K. , Li Yibing , Rong Chengli , Dastafkan Kamran , Su Zhen , Zhao Chuan
Published: April 2021

Nickel‐based electrocatalysts are promising candidates for oxygen evolution reaction (OER) but suffer from high activation overpotentials. Herein, in situ structural reconstruction of V‐doped Ni2P pre‐catalyst to form highly active NiV oxyhydroxides for OER is reported, during which the partial dissolution of V creates a disordered Ni structure with an enlarged electrochemical surface area. Operando electrochemical impedance spectroscopy reveals that the synergistic interaction between the Ni hosts and the remaining V dopants can regulate the electronic structure of NiV oxyhydroxides, which leads to enhanced kinetics for the adsorption of *OH and deprotonation of *OOH intermediates. Raman spectroscopy and X‐ray absorption spectroscopy further demonstrate that the increased content of active β‐NiOOH phase with the disordered Ni active sites contributes to OER activity enhancement. Density functional theory calculations verify that the V dopants facilitate the generation of *O intermediates during OER, which is the rate‐determining step for realizing efficient O2 evolution. Optimization of these properties endows the NiV oxyhydroxide electrode with a low overpotential of 221 mV to deliver a current density of 10 mA cm−2 and excellent stability in the alkaline electrolyte.
Controlling Electrochemically Induced Volume Changes in Conjugated Polymers by Chemical Design: from Theory to Devices
Authors: Moser Maximilian , Gladisch Johannes , Ghosh Sarbani , Hidalgo Tania Cecilia , Ponder James F. , Sheelamanthula Rajendar , Thiburce Quentin , Gasparini Nicola , Wadsworth Andrew , Salleo Alberto , Inal Sahika , Berggren Magnus , Zozoulenko Igor , Stavrinidou Eleni , McCulloch Iain
Published: April 2021

Electrochemically induced volume changes in organic mixed ionic‐electronic conductors (OMIECs) are particularly important for their use in dynamic microfiltration systems, biomedical machinery, and electronic devices. Although significant advances have been made to maximize the dimensional changes that can be accomplished by OMIECs, there is currently limited understanding of how changes in their molecular structures impact their underpinning fundamental processes and their performance in electronic devices. Herein, a series of ethylene glycol functionalized conjugated polymers is synthesized, and their electromechanical properties are evaluated through a combined approach of experimental measurements and molecular dynamics simulations. As demonstrated, alterations in the molecular structure of OMIECs impact numerous processes occurring during their electrochemical swelling, with sidechain length shortening decreasing the number of incorporated water molecules, reducing the generated void volumes and promoting the OMIECs to undergo different phase transitions. Ultimately, the impact of these combined molecular processes is assessed in organic electrochemical transistors, revealing that careful balancing of these phenomena is required to maximize device performance.
Additive‐Free Self‐Presodiation Strategy for High‐Performance Na‐Ion Batteries
Authors: Ding Feixiang , Meng Qingshi , Yu Pengfei , Wang Haibo , Niu Yaoshen , Li Yuqi , Yang Yang , Rong Xiaohui , Liu Xiaosong , Lu Yaxiang , Chen Liquan , Hu Yong‐Sheng
Published: April 2021

The irreversible consumption of sodium at the anode side during the first cycle prominently reduces the energy density of Na‐ion batteries. Different sacrificial cathode additives have been recently reported to address this problem; however, critical issues such as by‐products (e.g., CO2) release during cycling and incompatibility with current battery fabrication procedures potentially deteriorate the full‐cell performance and prevent the practical application. Herein, an additive‐free self‐presodiation strategy is proposed to create lattice‐coherent but component‐dependent O3‐NaxTMMnO2 (TM = transition metal ion(s)) cathodes by a quenching treatment rather than the general natural cooling. The quenching material preserves higher Mn3+ and Na+ content, which is able to release Na+ via Mn3+ oxidation to compensate for sodium consumption during the initial charge while adopting other TM to provide the capacity in the following cycles. Full cells fabricated with hard carbon anode and this material as both cathode and sodium supplement reagent have a nearly 9.4% cathode mass reduction, around 9.9% energy density improvement (from 233 to 256 Wh kg−1), and 8% capacity retention enhancement (from 76% to 84%) after 300 cycles. This study presents the route to rational design cathode materials with sodium reservoir property to simplify the presodiation process as well as improve the full‐cell performance.
Graphene‐Based Cementitious Composites: Toward Next‐Generation Construction Technologies
Authors: Krystek Małgorzata , Ciesielski Artur , Samorì Paolo
Published: April 2021

The search for technological solutions to the ever‐increasing demand for ultra‐high‐quality concrete with the simultaneous construction boom represents one of the greatest challenges concrete researchers are facing nowadays. In view of their unique properties, graphene and related materials, when utilized to form graphene‐based cementitious composites, appear to be powerful components to give a boost to today's concrete technology. In this review, the most enlightening recent advancements in the development of fabrication protocols for obtaining the homogenous dispersion of graphene and derivatives thereof within the cement matrix are showcased. The hydration process and basic properties of graphene‐based cementitious materials are also discussed. The integration of graphene‐family materials to concrete technology allows new functions to be imparted to cement composites toward the construction of smart and multifunctional buildings. Therefore, a specific focus is given to the electrical and piezoresistive behavior of graphene‐cement composites, and ultimately their great potential for structural health monitoring applications. The approaches proposed in this review can be also extended to other 2D materials offering the broadest arsenal of physical properties, which can therefore be integrated on‐demand in future smart structures and constructions.
Identifying the Electrostatic and Entropy‐Related Mechanisms for Charge‐Transfer Exciton Dissociation at Doped Organic Heterojunctions
Authors: Xue Wenyue , Tang Yabing , Zhou Xiaobo , Tang Zheng , Zhao Hanzhang , Li Tao , Zhang Lu , Liu Shengzhong (Frank) , Zhao Chao , Ma Wei , Yan Han
Published: April 2021

The electron donor/acceptor (D/A) heterojunction is the core for photocharge generation and recombination in organic photovoltaics (OPVs). Developing practical methods for the D/A heterojunction modification remains challenging and is rarely discussed in OPV research. Herein, the roles of molecular doping at the D/A heterojunction in the charge‐transfer exciton dissociation and detailed energy loss are investigated, and new insights are gained into the functions of doping on the OPV performance. Heterojunction doping simultaneously enhances all three OPV parameters, especially the short‐circuit current (Jsc). It is shown that the Jsc improvement is due to the combined effects of strengthened electric field and reduced activation energy, which is regulated via an entropy‐related mechanism. The performance enhancement is further demonstrated in homojunction devices showing the great potential of interfacial doping to overcome the intrinsic limitation between high Jsc and open‐circuit voltage (Voc) in OPVs.
MXene‐Derived TinO2n−1 Quantum Dots Distributed on Porous Carbon Nanosheets for Stable and Long‐Life Li–S Batteries: Enhanced Polysulfide Mediation via Defect Engineering
Authors: Zhang Heng , Yang Li , Zhang Peigen , Lu Chengjie , Sha Dawei , Yan Bingzhen , He Wei , Zhou Min , Zhang Wei , Pan Long , Sun ZhengMing
Published: April 2021

The application of Li–S batteries has been hindered by the shuttling behavior and sluggish reaction kinetics of polysulfides. Here an effective polysulfide immobilizer and catalytic promoter is developed by proposing oxygen‐vacancy‐rich TinO2n−1 quantum dots (OV–TnQDs) decorated on porous carbon nanosheets (PCN), which are modulated using Ti3C2Tx MXene as starting materials. The TnQDs not only confine polysulfides through strong chemisorption but also promote polysulfide conversion via redox‐active catalysis. The introduction of oxygen vacancies further boosts the immobilization and conversion of polysulfides by lowering the adsorption energy and shortening the bond lengths. The PCN provides a physical polysulfide confinement as well as a flexible substrate preventing OV–TnQDs from aggregation. Moreover, the two building blocks are conductive, thereby effectively improving the electron/charge transfer. Finally, the ultrasmall size of QDs along with the porous structure endows OV–TnQDs@PCN with large specific surface area and pore volume, affording adequate space for S loading and volume expansion. Therefore, the OV–TnQDs@PCN/S delivers a high S loading (79.1 wt%), good rate capability (672 mA h g−1 at 2 C), and excellent long‐term cyclability (88% capacity retention over 1000 cycles at 2 C). It also exhibits good Li+ storage under high S‐mass loading and lean electrolyte.
Heterochromatic Nonlinear Optical Responses in Upconversion Nanoparticles for Super‐Resolution Nanoscopy
Authors: Chen Chaohao , Liu Baolei , Liu Yongtao , Liao Jiayan , Shan Xuchen , Wang Fan , Jin Dayong
Published: April 2021

Point spread function (PSF) engineering by an emitter's response can code higher‐spatial‐frequency information of an image for microscopy to achieve super‐resolution. However, complexed excitation optics or repetitive scans are needed, which explains the issues of low speed, poor stability, and operational complexity associated with the current laser scanning microscopy approaches. Here, the diverse emission responses of upconversion nanoparticles (UCNPs) are reported for super‐resolution nanoscopy to improve the imaging quality and speed. The method only needs a doughnut‐shaped scanning excitation beam at an appropriate power density. By collecting the four‐photon emission of single UCNPs, the high‐frequency information of a super‐resolution image can be resolved through the doughnut‐emission PSF. Meanwhile, the two‐photon state of the same nanoparticle is oversaturated, so that the complementary lower‐frequency information of the super‐resolution image can be simultaneously collected by the Gaussian‐like emission PSF. This leads to a method of Fourier‐domain heterochromatic fusion, which allows the extended capability of the engineered PSFs to cover both low‐ and high‐frequency information to yield optimized image quality. This approach achieves a spatial resolution of 40 nm, 1/24th of the excitation wavelength. This work suggests a new scope for developing nonlinear multi‐color emitting probes in super‐resolution nanoscopy.
Surface‐Preferred Crystal Plane for a Stable and Reversible Zinc Anode
Authors: Zhou Miao , Guo Shan , Li Jialin , Luo Xiongbin , Liu Zhexuan , Zhang Tengsheng , Cao Xinxin , Long Mengqiu , Lu Bingan , Pan Anqiang , Fang Guozhao , Zhou Jiang , Liang Shuquan
Published: April 2021

Aqueous zinc‐ion batteries are largely restricted by the unsatisfactory performance of zinc (Zn) anodes, including their poor stability and irreversibility. In particular, the mechanism behind the electrochemical contrast caused by the surface crystal plane, which is a decisive factor of the electrochemical characteristics of the hostless Zn anode, is still relatively indistinct. Hence, new insight into a novel anode with a surface‐preferred (002) crystal plane is provided. The interfacial reaction and morphology evolution are revealed by theoretical analysis and post‐mortem/operando experimental techniques, indicating that Zn anodes with more exposed (002) basal planes exhibit free dendrites, no by‐products, and weak hydrogen evolution, in sharp contrast to the (100) plane. These features benefit the Zn (002) anode by enabling a long cyclic life of more than 500 h and a high average coulombic efficiency of 97.71% for symmetric batteries, along with delivering long cycling stability and reversibility with life spans of over 2000 cycles for full batteries. This work provides new insights into the design of high‐performance Zn anodes for large‐scale energy storage and can potentially be applied to other metal anodes suffering from instability and irreversibility.
Highly Efficient Electroluminescence from Narrowband Green Circularly Polarized Multiple Resonance Thermally Activated Delayed Fluorescence Enantiomers
Authors: Xu Yincai , Wang Qingyang , Cai Xinliang , Li Chenglong , Wang Yue
Published: April 2021

Purely organic fluorescent materials that concurrently exhibit high efficiency, narrowband emission, and circularly polarized luminescence (CPL) remain an unaddressed issue despite their promising applications in wide color gamut‐ and 3D‐display. Herein, the CPL optical property and multiple resonance (MR) effect induced thermally activated delayed fluorescence (MR‐TADF) emission are integrated with high color purity and luminous efficiency together. Two pairs of highly efficient green CP‐MR‐TADF enantiomers, namely, (R/S)‐OBN‐2CN‐BN and (R/S)‐OBN‐4CN‐BN, are developed. The enantiomer‐based organic light‐emitting diodes (OLEDs) exhibit pure green emission with narrow full‐width at half‐maximums (FWHMs) of 30 and 33 nm, high maximum external quantum efficiencies (EQEs) of 29.4% and 24.5%, and clear circularly polarized electroluminescence (CPEL) signals with electroluminescence dissymmetry factors (gEL) of +1.43 × 10−3/−1.27 × 10−3 and +4.60 × 10−4/−4.76 × 10−4, respectively. This is the first example of a highly efficient OLED that exhibits CPEL signal, narrowband emission, and TADF concurrently.
An Insightful Picture of Nonlinear Photonics in 2D Materials and their Applications: Recent Advances and Future Prospects
Authors: Ahmed Shakeel , Jiang Xiantao , Wang Cong , Kalsoom Um e , Wang Bing , Khan Jahanzeb , Muhammad Yasin , Duan Yanmin , Zhu Haiyong , Ren Xiangzhong , Zhang Han
Published: April 2021

The nonlinear optical (NLO) materials are playing a crucial role in almost all aspects of photonics including imaging frequency, manipulation, photon generation, transmission and detection. The nonlinear optics aims to investigate light response in NLO media, in which the NLO response is normally weak and low energy efficient. A comprehensive summary, discussion, and correlation of the light–matter interaction in the 2D nano‐platform, like graphene and TMDCs, would be inspirational and timely needed. In this contribution, a broad overview and discussion about recent experimental evolution regarding the NLO response and its corresponding applications in various 2D materials are presented. A wide material library including graphene, transition metal dichalcogenides, black phosphorus, MXenes, semimetals, polymer materials, and hybrid structures (0D, 1D, 3D) are discussed. In this review, the qualitative description of NLO is firstly illustrated, followed by various fundamental NLO processes being highlighted. Fundamental limits of nonlinear optics and some of NLO applications are prospected. It is hoped that this comprehensive review will shed a light on the development of nonlinear optics with 2D materials to be applied in the field of photonics and optoelectronics.
Plasmonic Nanotweezers and Nanosensors for Point‐of‐Care Applications
Authors: Peng Xiaolei , Kotnala Abhay , Rajeeva Bharath Bangalore , Wang Mingsong , Yao Kan , Bhatt Neel , Penley Daniel , Zheng Yuebing
Published: April 2021

The capabilities of manipulating and analyzing biological cells, bacteria, viruses, deoxyribonucleic acids (DNAs), and proteins at high resolution are significant in understanding biology and enabling early disease diagnosis. The progress in developments and applications of plasmonic nanotweezers and nanosensors is discussed, where the plasmon‐enhanced light‐matter interactions at the nanoscale improve the optical manipulation and analysis of biological objects. Selected examples are presented to illustrate their design and working principles. In the context of plasmofluidics, which merges plasmonics and fluidics, the integration of plasmonic nanotweezers and nanosensors with microfluidic systems for point‐of‐care (POC) applications is envisioned. Perspectives on the challenges and opportunities in further developing and applying the plasmofluidic POC devices are provided.
Self‐Assembled Ag2S‐QD Vesicles for In Situ Responsive NIR‐II Fluorescence Imaging‐Guided Photothermal Cancer Therapy
Authors: Liu Tianji , Zhang Xuan , Liu Dezhi , Chen Bin , Ge Xiaoguang , Gao Shi , Song Jibin
Published: April 2021

Bioimaging guided photothermal therapy possesses great promise for lesion diagnosis and effective treatment. However, distinguishing lesion from normal tissues for precise cancer therapy remains a great challenge. Herein, a stimulation‐responsive assembled Ag2S vesicle (Ag2S Ve) is proposed by self‐assembly of Ag2S quantum dots (QDs) coated with pH‐sensitive copolymer thiolated polystyrene‐co‐poly(4‐vinylpyridine). The Ag2S Ve shows significant absorption enhancement in the near‐infrared (NIR) region and strong fluorescence inhibition in the second near infrared (NIR‐II) region. Triggered by the acidic environment, the release of Ag2S QDs promptly mediates the quenched NIR‐II fluorescence from “off” to “on.” In vivo studies reveal that the theranostic Ag2S Ve can be specifically activated in acidic tumor tissues, whereas it exhibits nonfunctional in normal tissues. Larger sizes endow vesicles a higher tumor accumulation efficiency and controllable disassembly shows illuminating characteristics toward lesion tissues, which provides an innovative therapeutic strategy for activated NIR‐II fluorescence imaging guided cancer therapy.
Nonlinear Optical Thermometry—A Novel Temperature Sensing Strategy via Second Harmonic Generation (SHG) and Upconversion Luminescence in BaTiO3:Ho3+,Yb3+ Perovskite
Authors: Zheng Teng , Runowski Marcin , Martín Inocencio R. , Lis Stefan , Vega Mauricio , Llanos Jaime
Published: April 2021

Nonlinear optical spectroscopy may be a powerful tool for sensing of various intrinsic properties of materials and different state functions of the system. This is due to the strong dependence of nonlinear phenomena on numerous physicochemical factors. The feasibility of simultaneously employing the second harmonic generation (SHG) and upconversion luminescence (UCL) processes in BaTiO3:Ho3+,Yb3+ for optical temperature sensing is demonstrated for the first time. Under 976 nm laser excitation, the evolution of the SHG and UCL band intensity ratio is correlated with temperature and calibrated within the temperature range of 25–305 °C. The band intensity ratio between SHG and UCL exhibits a sigmoidal dependence on temperature, and, hence, it can allow the detection of phase transitions from non‐centrosymmetric to centrosymmetric systems, and vice versa. Most importantly, from the perspective of optical temperature sensing, this work provides a novel and effective strategy for nonlinear optical thermometry, with high sensitivity of up to 2.78% °C–1.
Effectively Enhanced Broadband Phototransistors Based on Multilayer WSe2/Pentacene
Authors: Im Healin , Kim Sunkook
Published: April 2021

Broadband photodetectors sensitive to light from visible to near‐infrared are essential for various applications such as thermal evaluation, bio‐imaging mapping, and bio‐health monitoring. Multilayer WSe2 offers broad light spectral responses and roles in broadband phototransistors’ active matrix. However, it shows relatively lower photoresponsivity than monolayer WSe2 due to layer‐dependent energy band variations. Pentacene islands, a p‐type organic material, are formed on the multilayer WSe2 to enhance its photoresponsivity under broadband lights. Pentacene islands can prominently absorb ultra‐violet to visible lights and generate enormous excitons. Besides, they have relatively long exciton diffusion lengths in micrometer scales to effectively enable exciton migration and charge transfer at the pentacene and WSe2 interface. Consequently, the photocurrent (Iph) and the photoresponsivity (Rph) in WSe2/pentacene transistors are 1.41 µA and 19.313 A W−1 for 638‐nm light and 0.20 µA and 1.16 A W−1 for 852‐nm light. Therefore, WSe2/pentacene‐based phototransistors can be applied for broadband photodetectors under visible to near‐infrared.
High‐Efficiency Microwave Attenuation of Magnetic Carbon Nanoparticle‐Decorated Tubular Carbon Nanofibers Composites at an Ultralow Filling Content
Authors: Kang Shuai , Qiao Shiya , Cao Yutong , Hu Zuming , Yu Junrong , Wang Yan
Published: April 2021

Faced with the formidable challenge to achieve a powerful absorption and broad bandwidth under a thin response thickness at a low filler content, tailoring the composition and microstructure of the absorbers is generally regarded as a potential method to tackle it. In the study, unprecedented tubular carbon nanofiber/Co/nanoporous carbon (TCNFs/Co/NPC) hybrids with rich holes are obtained by the direct thermal treatment of tubular polymer nanofibers/ZIF‐67 (TPNFs/ZIF‐67) precursor, which is fabricated by controllable anchor of ZIF‐67 nanocrystals on the surface of sulfonated TPNFs (TPNFs‐SO3H). The dielectric parameters of the resultant samples are reasonably monitored by adjustable TPNFs‐SO3H dosage and filling content. Benefiting from the dielectric‐magnetic compositions and unique heterogeneous and porous configurations, the boosted impedance matching and polarization relaxation are given. Hence, under an ultralow filling content of 8 wt%, a minimum reflection loss (RLmin) value of −54.1 dB corresponding to a matching thickness of 2 mm and an effective absorption bandwidth (EAB) of 6.2 GHz at 2.5 mm are exhibited at the TPNFs‐SO3H usage of 100 mg and carbonization temperature of 700 °C, respectively. This work provides an instructive guidance for constructing highly efficient absorbers with strong attenuation and wide frequency range at a low thickness.
Thermoelectric Metamaterials: Nano‐Waveguides for Thermoelectric Energy Conversion and Heat Management at the Nanoscale
Authors: Zianni Xanthippi
Published: April 2021

The idea of using metamaterials for thermoelectrics was proposed 10 years ago. Enhanced thermoelectric effects and decreased thermal conduction are theoretically demonstrated due to modification of electrons and phonons by quantum interference between propagating and scattered waves at geometrical discontinuities. These structures are now considered promising for breakthrough in thermoelectric energy conversion and heat management at the nanoscale. They could ideally power the Internet of things. This review is devoted to electron and phonon transport properties of thermoelectric metamaterials in the quantum confinement regime. Enhanced thermoelectric effects and decreased thermal conductivity are related with geometrically induced fluctuations, resonances, quasi‐localized states, and minibands. Conduction fluctuations show generic behavior amenable to experimental confirmation. It is emphasized that both electrons and phonons are affected by geometry modulation and that, contrary to what is often assumed, their properties cannot be a priori tuned independently. Effects of periodicity and disorder on electrons and phonons in the same structures indicate strategies to design geometry modulation for high thermoelectric efficiency. Generic principles of operation boost prospects to make technologically important materials (e.g., Si, III–Vs, graphene) efficient thermoelectric materials. Geometrically enhanced thermoelectric properties and controlled heat conduction can cooperate with other functionalities of metamaterials for next‐generation nanodevices.
Single‐ or Poly‐Crystalline Ni‐Rich Layered Cathode, Sulfide or Halide Solid Electrolyte: Which Will be the Winners for All‐Solid‐State Batteries?
Authors: Han Yoonjae , Jung Sung Hoo , Kwak Hiram , Jun Seunggoo , Kwak Hunho H. , Lee Jong Hoon , Hong Seung‐Tae , Jung Yoon Seok
Published: April 2021

Two newly emerging materials for application in all‐solid‐state batteries, namely, single‐crystalline Ni‐rich layered oxide cathode and halide solid electrolyte (SE), are of utmost interest because of their superior properties (good microstructural integrity and excellent electrochemical oxidation stability, respectively) to conventional polycrystalline layered oxides and sulfide SEs. In this work, four electrodes employing single‐ or polycrystalline LiNi0.88Co0.11Al0.01O2 (NCA) and Li3YCl6 or Li6PS5Cl0.5Br0.5 are rigorously characterized by complementary analyses. It is shown that the synergy of employing cracking‐free single‐crystalline NCA and oxidation‐tolerable Li3YCl6 can be achieved by considering intercoupled engineering factors that are prone to overlook, such as size, lightness, and mixing of particles. Accordingly, the highest level of performances in terms of discharge capacity (199 mA h g−1 at 0.1C), initial Coulombic efficiency (89.6%), cycling performance (96.8% of capacity retention at the 200th cycle), and rate capability (130 mA h g−1 at 4C) are demonstrated at 30 °C. Severe side reactions occurring at the Li6PS5Cl0.5Br0.5/NCA interfaces are also quantified and probed. Importantly, an overlooked but significant contribution of the side reaction of Li6PS5Cl0.5Br0.5 to the detrimental electrochemo‐mechanical degradation of polycrystalline NCA is revealed for the first time by postmortem scanning electron microscopy and operando electrochemical pressiometry measurements.
Porosity Engineering of MOF‐Based Materials for Electrochemical Energy Storage
Authors: Du Ran , Wu Yifan , Yang Yuchen , Zhai Tingting , Zhou Tao , Shang Qiyao , Zhu Lihua , Shang Congxiao , Guo Zhengxiao
Published: April 2021

Metal–organic frameworks (MOFs) feature rich chemistry, ordered micro‐/mesoporous structure and uniformly distributed active sites, offering great scope for electrochemical energy storage (EES) applications. Given the particular importance of porosity for charge transport and catalysis, a critical assessment of its design, formation, and engineering is needed for the development and optimization of EES devices. Such efforts can be realized via the design of reticular chemistry, multiscale pore engineering, synthesis methodologies, and postsynthesis treatment, which remarkably expand the scope of applications. By imparting conductive backbones, guest compounds, and/or redox‐active centers, MOFs and their derivatives have been heavily explored for EES in the last decade. To improve the design of MOF‐based materials for EES, the strategies of pore architecturing of MOFs and their derivatives are systematically analyzed and their applications reviewed for supercapacitors and metal‐ion batteries. Potential challenges and future opportunities are also discussed to guide future development.
Metal‐Organic Frameworks Nanocomposites with Different Dimensionalities for Energy Conversion and Storage
Authors: Bai Yang , Liu Chunli , Shan Yuying , Chen Tingting , Zhao Yan , Yu Chao , Pang Huan
Published: April 2021

Metal‐organic frameworks (MOFs) have emerged as a promising material with unique features such as diverse composition, high porosity, tunable pore structure, and versatile functionality. These characteristics have attracted significant research interest in photochemical and electrochemical energy conversion and storage (ECS). However, the utilization of pristine MOFs in ECS is still hindered by their limited conductivity and functionality. Recently, the integration of MOFs with functional materials has been studied intensively to surmount the deficiencies of pristine MOFs while maintaining their original advantages. The MOFs act as the essential active species, or as supports to accommodate and stabilize these materials. The incorporation can deliver synergistic effects and enhance the properties of MOFs, thus greatly improving their efficiency and stability in ECS. The favorable nanostructures of MOF composites with different dimensionalities including 0D, 1D, 2D, and 3D can further enrich their structural diversity. Their advanced nanostructures contribute greatly to the enhanced structural robustness, exposure of active sites, and mass/electron transport, which are promising for practical ECS. In this review, recent progress in the rational design of MOF composites with different dimensionalities is summarized. The extensive applications of MOF composites for ECS systems are also discussed for elucidating their advantages, challenges, and prospects.
Climatic constraints to yield and yield components of temperate japonica rice
Authors: Kim Yean‐Uk , Moon Kanghyun , Lee Byun‐Woo
Published: April 2021

Although temperate japonica rice (Oryza sativa L.) production is limited by both low‐ and high‐temperature stresses, the primary constraint was reported to be cold stress in the past. However, the magnitudes of low‐ and high‐temperature stresses may have been altered by global warming. In this study, the major climatic constraints to the yield and yield components of temperate japonica rice grown in field conditions under the current climates were assessed using the random forests method with 14‐yr field trial data (n = 499). Low temperatures had negligible impacts on rice yield under the current climates (2005–2018) in South Korea. Meanwhile, high‐temperature stress was most significant during the ripening stage, followed by the reproductive stage. Yield losses by high temperatures were primarily associated with reduced filled‐grain percentage, followed by reduced 1,000‐grain weight. During the vegetative stage, higher temperature (or higher growing degree days, GDD) decreased the number of panicles per m2 and increased the number of spikelets per panicle, resulting in negligible changes in the number of spikelets per m2 and yield. The effect of solar radiation was most significant during the ripening stage. More solar radiation during the ripening stage enhanced rice yield by increasing filled‐grain percentage and 1,000‐grain weight. This study highlights that the primary constraints to temperate japonica rice grown under the current climates are high‐temperature stresses during the ripening and reproductive stages rather than low‐temperature stresses. Thus, there is an urgent need to explore options for improving the adaptation of temperate japonica rice to anticipated global warming.
Genotype by environment interaction on phenology and synchronous maturity of mungbean
Authors: Marwiyah Siti , Suwarno Willy Bayuardi , Wirnas Desta , Trikoesoemaningtyas  , Sutjahjo Surjono Hadi
Published: April 2021

Genotype × environment interaction (G×E) of harvest period should be involved to assess the suitability of mungbean (Vigna radiata L. Wilczek) for monoculture or intercropping cultivations. This research was aimed to study the effect of G×E interactions on phenology and synchronous maturity, the change of genetic parameter estimates, and the stability of harvest period in mungbean. The study was conducted in Bogor, Indonesia, from December 2017 to October 2018 in four environments: wet season, monoculture (WS.M) and intercropping (WS.I); dry season, monoculture (DS.M) and intercropping (DS.I). Ten mungbean genotypes were evaluated in monoculture and intercropping with sorghum [Sorghum bicolor (L.) Moench] cultivar Numbu using a randomized complete block design with three replications. The phenological traits, namely days to flowering, days to the first harvest, days to 90% harvest, plant height, number of productive branches, seed weight per plant (SWP), and the synchronous maturity traits, namely harvest period, degree indetermination of plant height (DDh1), degree of indetermination of harvest period (DDd2), were observed. The results showed that the G×E interaction effect was highly significant (p < .01) for all phenological and synchronous maturity traits except DDd2. Phenotypic expression of all traits, except SWP and DDh1, were largely controlled by the genetic factor (h2bs > 59.83%). Kefa, Kawur, VR480B, Lom2, MLB, Vima 2, VR10, VR60 were stable (bi = 1), VR05 was sensitive (bi = 1.70), and No.129 was insensitive (bi = 0.66) and suitable for monoculture in the dry season. The GGE biplot showed Kefa as a stable genotype with the shortest harvest period. Mungbean selection for synchronous maturity can use harvest period trait in monoculture at dry season.
Genetic parameters and selection indexes in F2 and F2:3 soybean populations
Authors: Silva Carolina Oliveira , Hamawaki Osvaldo Toshiyuki , Nogueira Ana Paula Oliveira , Almeida Myckell Ramos Campos de , Castro Douglas Goulart , Marques Fábio Serafim , Lemes Hamawaki Raphael , Hamawaki Cristiane Divina Lemes , Cardoso Gabriela Marques , Diniz Victor Hugo Rodrigues
Published: April 2021

The evaluation of genetic parameters in early generations select individuals in F2 and F2:3 and advancing only progenies with the potential to generate pure productive lines. The objectives of this study were to estimate genetic and phenotypic parameters in F2 and F2:3 populations derived from UFUS 7415 and TMG 7161 RR, evaluate different genotype selection strategies, and select progenies to improve agronomic traits. Populations in the F2 and F2:3 generations derived from a biparental cross between the parents UFUS 7415 and TMG  7161 RR were evaluated. The genetic parameters of 360 individuals in the F2 generation and 150 genotypes of each parent were evaluated. Heritability varied from 4.66% for the number of seeds per pod to 86.06% for plant height at flowering. The greatest selection gain was obtained for plant height at flowering (29.68%), related to grain production. In the F2:3 generation, 145 genotypes were evaluated and their parents, in a randomized block design with two replications. The correlations between characters and the genetic gains obtained by direct and indirect selection and based on the genotype–ideotype distance index and the Mulamba and Mock index of the sum of “ranks” were evaluated. With direct selection, selection gains ranged from –5.34 to 16.19%. The genotype–ideotype distance index showed a total selection gain of 40.49%, while the Mulamba and Mock index of the sum of ranks obtained a total gain of 39.35%. Twenty‐three genotypes were selected for the characters evaluated with both indexes in the F3 generation.
Racial disparities in the survival of patients with indolent non‐Hodgkin lymphomas in the United States
Authors: Vaughn John L. , Spies Daniela , Xavier Ana C. , Epperla Narendranath
Published: April 2021

There is a paucity of data regarding racial disparities in the survival of patients with indolent non‐Hodgkin lymphomas (iNHL) in the contemporary time‐period. Hence, we sought to determine whether racial disparities exist in the survival of patients with iNHLs in the US. We included 68 059 adult patients with follicular lymphoma (FL, n = 41 943), marginal zone lymphoma (MZL, n = 22 485), and lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM, n = 3631) who were diagnosed in the US between 2000 and 2017. Race was categorized as White, Black, Asian/Pacific Islander, or American Indian/Alaska Native (API/AI). The primary outcome was relative survival (RS), which was estimated using flexible parametric survival models. The RS estimates varied according to race and disease histology but were consistently lower for racial minorities, including those diagnosed during the most recent 5‐year time‐period of 2012–2017. On multivariable analysis for RS, Black patients with FL had a 32% higher excess mortality rate compared to White patients [adjusted excess hazard ratio (aEHR), 1.32; 95% CI, 1.15–1.51; p < .001], corresponding to a difference of 55 (95% CI, 24–86) excess deaths per 10 000 person‐years. For MZL, Black patients had a 40% higher excess mortality rate compared to White patients (aEHR 1.40; 95% CI, 1.18–1.66; p < .001), corresponding to a difference of 62 (95% CI, 26–98) excess deaths per 10 000 person‐years. No significant racial differences were detected for patients with WM. The greatest disparity was seen for younger Black patients with FL. Our findings highlight the need for interventions to improve the outcomes of Black patients with iNHLs, particularly younger Black patients with FL.
What Shall We Do with the Computed Detonation Performance? Comment on “1,3,4‐Oxadiazole Bridges: A Strategy to Improve Energetics at the Molecular Level”
Authors: Muravyev Nikita V.
Published: April 2021

In this Correspondence, a question is raised on how confident are the computed detonation performance values. Consideration of the energetic materials in a recent Research Article in this journal and some other newly synthesized promising compounds shows that the variation between the available methods of calculation is surprisingly high.
Advances and Challenges for the Electrochemical Reduction of CO2 to CO: From Fundamentals to Industrialization
Authors: Jin Song , Hao Zhimeng , Zhang Kai , Yan Zhenhua , Chen Jun
Published: April 2021

The electrochemical carbon dioxide reduction reaction (CO2RR) provides an attractive approach to convert renewable electricity into fuels and feedstocks in the form of chemical bonds. Among the different CO2RR pathways, the conversion of CO2 into CO is considered one of the most promising candidate reactions because of its high technological and economic feasibility. Integrating catalyst and electrolyte design with an understanding of the catalytic mechanism will yield scientific insights and promote this technology towards industrial implementation. Herein, we give an overview of recent advances and challenges for the selective conversion of CO2 into CO. Multidimensional catalyst and electrolyte engineering for the CO2RR are also summarized. Furthermore, recent studies on the large‐scale production of CO are highlighted to facilitate industrialization of the electrochemical reduction of CO2. To conclude, the remaining technological challenges and future directions for the industrial application of the CO2RR to generate CO are highlighted.
Exploring ortho‐(4,4′‐dimethoxybenzhydryl) substitution in iron ethylene polymerization catalysts: Co‐catalyst effects, thermal stability, and polymer molecular weight variations
Authors: Liu Tian , Ma Yanping , Solan Gregory , Liang Tongling , Sun Wen‐Hua
Published: April 2021

Six different types of 4,4′‐dimethoxybenzhydryl‐substituted bis(arylimino)pyridine‐iron(II) chloride complex—[2‐{{2,6‐((p‐MeOPh)2CH)2‐4‐MeC6H2}N=CMe}‐6‐(ArN=CMe)C5H3N]FeCl2 (Ar = 2,6‐Me2C6H3 (Fe1), 2,6‐Et2C6H3 (Fe2), 2,6‐iPr2C6H3 (Fe3), 2,4,6‐Me3C6H2 (Fe4), 2,6‐Et2‐4‐MeC6H2 (Fe5), 2,6‐((p‐MeOPh)2CH)2‐4‐MeC6H2 (Fe6)—are reported. The molecular structures of Fe2 and Fe3 emphasize the unsymmetrical nature of the N,N,N‐chelating ligand and the steric protection exerted by the ortho‐(4,4′‐dimethyoxybenzhydryl) groups. A range in catalytic activities for ethylene polymerization was observed when Fe1–Fe6 were treated with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO). In particular, Fe1/MAO bearing the least bulky N‐2,6‐dimethylphenyl group exhibited a very high activity of 1.11 × 107 g (PE) mol−1 (Fe) h−1 at 70°C/10 atm over a 30‐min run time that remained high even after 60 min, an observation highlighting its appreciable catalyst lifetime and thermal stability. In addition, the polyethylene formed by this catalyst class displayed desirable characteristics such as high linearity and high molecular weight (Mw range: 5.17–7.62 × 105 g mol−1). Indeed, the molecular weight of the polymer produced using Fe1 (with MAO or MMAO) exceeds that obtained using related benzhydryl‐containing bis(imino)pyridine‐iron catalysts. As a general feature, activation of Fe1–Fe6 with MMAO led to lower activity and lower molecular weight polyethylene, especially for runs performed at 1 atm ethylene pressure.
In vitro and in vivo evaluation of degradability and biocompatibility of poly(p‐dioxanone) hemostatic clips for laparoscopic surgery
Authors: Zheng Heng , Peng Haitao , Wang Peng , Li Hong , Li Lin , Du Yan , Lv Guoyu
Published: April 2021

For the clinical application of biodegradable hemostatic surgical clips in laparoscopic surgery, it is necessary to determine their degradability and biocompatibility. Herein, in vitro and in vivo studies were undertaken to evaluate the degradability and biocompatibility of bioabsorbable clips made of poly(p‐dioxanone). Changes in weight loss, pull‐off force, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) of the poly(p‐dioxanone) clips were determined after they were degraded in deionized water and phosphate buffer saline for the in vitro experiment and in laparoscopic models of bile duct ligation(BDL) and right gastroepiploic artery ligation(GEAL) using New Zealand white rabbits for the in vivo experiment. Changes in weight loss and pull‐off force were greater in the in vivo experiment than the in vitro experiment. DSC showed the greatest variation in the degree of crystallinity of the clips degraded in deionized water. Stark differences in SEM were observed after 4 weeks of degradation both in vitro and in vivo. Furthermore, the cytocompatibility of the clips was considered satisfactory because the L929 cells could adhere to the clips and proliferate adequately in the presence of the clip extract. Biocompatibility was inferred based on the histological analysis of BDL and GEAL, no significant inflammatory responses were observed after 4 weeks of ligation.