bluuebunny/crossref_metadata_2025_split huggingface dataset:
Self‐Rolling SiO2/Au Based Epsilon‐Near‐Zero Metamaterials
Authors: Habib Mohsin , Issah Ibrahim , Bermúdez‐Ureña Esteban , Caglayan Humeyra 
Published: May 2022

AbstractWave propagation in epsilon‐near‐zero (ENZ) media offers exciting possibilities in the field of nanophotonics. Here, a thin film self‐rolling technique to fabricate SiO2/Au based 3D multilayer structures is implemented. These cylindrical multilayer metamaterials are utilized to take advantage of the material dispersion as well as the structural dispersion to obtain self‐rolling ENZ metamaterials at the visible to near‐infrared wavelength range. The ENZ features are investigated initially by modelling the dispersion of the effective medium using circular effective medium approximation and further by the characterization of the optical response. Moreover, the potential of these structures for supporting an ENZ waveguide mode is demonstrated. This platform for dispersion engineering and obtaining ENZ metamaterials can provide opportunities for unique applications which cannot be possible with planar systems. It can be used to integrate active materials before the rolling process to actively control the layer properties, or embed single‐layer materials within different layers of ENZ metamaterials with potential applications in quantum nanophotonics.
Visible‐Light‐Enabled Photosensitizer‐ and Additive‐Free Decarboxylative Coupling Cyclization of Enaminone withN‐Arylglycine for 3‐Aminoalkyl Chromones
Authors: Zhu Zhi‐Qiang , Hu Jia‐Yu , Xie Zong‐Bo , Tang Juan , Le Zhang‐Gao 
Published: May 2022

AbstractAn photosensitizer‐ and additive‐free, visible‐light‐induced decarboxylative aminoalkylation/C−O coupling cyclization of enaminones withN‐arylglycine for the synthesis of 3‐aminoalkyl chromones has been achieved. This synthetic method features good functional‐group tolerance, mild reaction conditions and no request of photocatalyst or additive, thus making this protocol more practical and sustainable.magnified image
Fabrication and Optimization of CdSe Solar Cells for Possible Top Cell of Silicon‐Based Tandem Devices
Authors: Li Kanghua , Yang Xuke , Lu Yue , Xue Jiayou , Lu Shuaicheng , Zheng Jiajia , Chen Chao , Tang Jiang 
Published: May 2022

AbstractSilicon‐based tandem solar cells are regarded as one of the most feasible ways to break the single‐junction Shockley–Queisser limit efficiency and further reduce the cost of solar electricity. Recently, wide‐bandgap (≈1.7 eV) perovskite solar cells have drawn intense research interest as the top cell for Si‐based tandem devices. Despite significant progress in device efficiency, the unsatisfactory stability of perovskites is still a huge concern. Besides halide perovskites, there are many inorganic semiconductors worthy of investigation. It is believed that cadmium selenide, a binary compound enjoying outstanding optoelectronic properties, high stability, and low cost, is very promising as the top cell for Si‐based tandem devices. Herein, the CdSe thin‐film solar cells that have been neglected for 3 decades are revisited. Using rapid thermal evaporation, high‐quality CdSe thin films with large grain size, high‐photoluminescence, small Stokes shift, and intrinsic n‐type conductivity are obtained. Furthermore, CdSe solar cells are redesigned and a champion efficiency of 6.00% is achieved. Through in‐depth analysis, it is identified that bulk and interface defects limit the open‐circuit voltage and hence device performance. This work highlights the great potential of CdSe solar cells as top cells for Si‐based tandem devices.
Inhalation‐Driven Vertical Flutter Triboelectric Nanogenerator with Amplified Output as a Gas‐Mask‐Integrated Self‐Powered Multifunctional System
Authors: Heo Deokjae , Song Myunghwan , Chung Seh‐Hoon , Cha Kyunghwan , Kim Youna , Chung Jihoon , Hwang Patrick T.J. , Lee Jaeheon , Jung Heesoo , Jin Youngho , Hong Jinkee , Kim Min‐Kun , Lee Sangmin 
Published: May 2022

AbstractWith the widespread use of sensors and small electronics in the Internet of Things (IoT) era, triboelectric nanogenerators (TENGs) have emerged as sustainable and renewable energy sources owing to their high efficiency, compatibility with various materials, and low cost. However, the existing TENGs exhibit a low current output and require a large mechanical input to continuously generate an enhanced current output. In this study, an inhalation‐driven vertical flutter TENG (IVF‐TENG) with an amplified current output is developed. The IVF‐TENG exhibits two types of mechanical behaviors simultaneously, generating a high‐frequency continuous electrical voltage and closed‐circuit current (ICC) output of 17 V and 1.84 μA, respectively, during inhalation, and an electrostatic discharge voltage and ICC output of 456 V and 288 mA at the beginning and end of every inspiratory cycle, respectively. As a user‐position‐indicating light, the IVF‐TENG can power 130 LEDs in series and 140 LEDs in parallel for every inhalation. The IVF‐TENG can charge a capacitor of 660 μF, with a discharge process of a few seconds, to power a commercial Bluetooth tracker and wirelessly transfer the Bluetooth signal to a smartphone. Moreover, the IVF‐TENG can detect the user's respiration state or the presence of chemical warfare agents (GB, DMMP, etc.) via output waveforms.
Anode‐Free Solid‐State Lithium Batteries: A Review
Authors: Huang Wen‐Ze , Zhao Chen‐Zi , Wu Peng , Yuan Hong , Feng Wei‐Er , Liu Ze‐Yu , Lu Yang , Sun Shuo , Fu Zhong‐Heng , Hu Jiang‐Kui , Yang Shi‐Jie , Huang Jia‐Qi , Zhang Qiang 
Published: May 2022

AbstractAnode‐free solid‐state lithium batteries are promising for next‐generation energy storage systems, especially the mobile sectors, due to their enhanced energy density, improved safety, and extended calendar life. However, the inefficiency of lithium plating and stripping leads to rapid capacity degradation due to the absence of excess lithium inventory. Therefore, dissecting the difficulties and challenges faced by anode‐free solid‐state lithium batteries can pave the way to improving the cycle life of many lithium batteries. In this review, the key issues affecting capacity degradation are elaborated step‐by‐step based on the current understanding of anode‐free solid‐state lithium batteries. Furthermore, various strategies for optimizing performance are targeted. Finally, future opportunities and possible directions for anode‐free solid‐state lithium batteries are evaluated, aiming to stimulate the exploration of this emerging field.
Synergistic Effect of Band and Nanostructure Engineering on the Boosted Thermoelectric Performance of n‐Type Mg3+δ(Sb, Bi)2 Zintls
Authors: Liang Ji‐Sheng , Shi Xiao‐Lei , Peng Ying , Liu Wei‐Di , Yang Heng‐Quan , Liu Cheng‐Yan , Chen Jun‐Liang , Zhou Qi , Miao Lei , Chen Zhi‐Gang 
Published: May 2022

AbstractThermoelectric Mg3+δ(Sb, Bi)2 Zintls have attracted significant attention because of their high‐performing, eco‐friendly, and cost‐effective features, but their thermoelectric properties still need improvement for application to practical devices. Here an outstanding ZT of ≈1.87 at 773 K and a high average ZT of ≈1.2 in n‐type Y‐doped Mg3.2Sb1.5Bi0.49Se0.01 are reported, both of which rank as top values among the reported literature. First‐principles calculations indicate that substituting the Mg site with Y shifts the Fermi level into the conduction band and simultaneously narrows the bandgap, both strengthening the n‐type semiconducting feature and boosting the electron carrier density of Mg3.2Sb1.5Bi0.49Se0.01. A high power factor of ≈21.4 µW cm–1 K–2 is achieved at 773 K in Mg3.18Y0.02Sb1.5Bi0.49Se0.01, benefiting from the rationally tuned carrier density of ≈7.7 × 1019 cm–3 at this temperature. In addition, the doped Ys act as point defects to cause significant lattice distortions and strains, confirmed by comprehensive micro/nanostructure characterizations. These lattice imperfections suppress the lattice thermal conductivity to ≈0.41 W m–1 K–1 at 773 K, leading to such a high ZT. Furthermore, a high energy conversion efficiency of ≈13.8% is predicted by a temperature gradient of 450 K, indicating a great potential to be applied to practical devices for mid‐temperature applications.
Emerging Strategies toward Mechanically Robust Organic Photovoltaics: Focus on Active Layer
Authors: Yan Cenqi , Qin Jiaqiang , Wang Yinghan , Li Gang , Cheng Pei 
Published: May 2022

AbstractMechanical stability of organic photovoltaics (OPVs) is required not just for portable applications, which must accommodate strain as a function of operation, but also for manufacturing, transportation, and utility‐scale applications. However, the mechanical reliability of OPVs is often disregarded compared with other stress (thermal, oxygen, moisture, irradiation). The key to improving the mechanical stability of OPVs lies in realizing mechanically robust active layers. This perspective first analyzes working scenarios of flexible OPVs (static and dynamic conditions) and strategies toward achieving mechanically robust active layers. Then, the recent achievements in improving the mechanical robustness of active layers are summarized in the aspects of all‐polymer active layers, single‐component active layers, and third component strategies. In the end, an outlook and perspective on the future of the field are provided to help improve the mechanical stability of active layers.
Increasing the Pressure‐Free Stripping Capacity of the Lithium Metal Anode in Solid‐State‐Batteries by Carbon Nanotubes
Authors: Fuchs Till , Haslam Catherine G. , Moy Alexandra C. , Lerch Christian , Krauskopf Thorben , Sakamoto Jeff , Richter Felix H. , Janek Jürgen 
Published: May 2022

AbstractLithium metal is the key anode material for solid‐state‐batteries as its successful implementation will drastically increase their energy and power densities. However, anode contact loss during stripping leads to dendrites upon plating and subsequent cell failure. Design strategies to mitigate these issues are crucial to enable the use of lithium metal anodes. This paper reports the dissolution kinetics of composite anodes made of lithium metal and carbon nanotubes (CNTs) with a garnet‐type solid electrolyte (SE). In addition to an enhancement of the effective diffusion within the anode, its dissolution is fundamentally changed from being 2D to 3D. By maintaining contact with the SE, the CNTs facilitate lithium transport to the interface, which yields more than 20 mAh cm−2 discharge capacity at 100 µA cm−2 without the application of external stack pressure (>1 MPa). Conclusions drawn from electrochemical data on the anode microstructure are validated using cryo‐focused‐ion‐beam scanning electron microscopy and correlated with the mechanical properties. Micro‐indentation, acoustic analysis, and stress–strain testing show that mechanical properties of the anode, like yield strength and hardness, are adjustable. Overall, it is shown that the mechanical and electrochemical properties of Li–CNT composite electrodes can be tailored to suit the requirements of a practical cell.
Optical properties of gold nanoclusters constructed from Au13 units
Authors: Kong Jie , Zhang Wei , Wu Yanzhen , Zhou Meng 
Published: May 2022

AbstractAtomically precise gold nanoclusters with diameters of 1–3 nm have attracted considerable research interests in the past decade because they fill the gap between small organic‐metal complexes (<1 nm) and metal nanoparticles (>3 nm). Au13 nanocluster with icosahedral structure is a ubiquitous unit widely applied in nanocluster assembly. In this minireview, we introduce the optical properties of gold nanoclusters constructed from Au13 units. We first discuss the optical absorption and photoluminescence of Au13, Au25, Au37, and Au60 clusters. We then discuss the ultrafast dynamics, the detailed excited‐state deactivation processes, and the origin of coherent oscillations of the Au13 homologous clusters. Finally, we provide our outlook on the future direction on this topic.
Patterns of venous thromboembolism risk, treatment, and outcomes among patients with cancer from uninsured and vulnerable populations
Authors: da Costa Wilson L. , Guffey Danielle , Oluyomi Abiodun , Bandyo Raka , Rosales Omar , Wallace Courtney D. , Granada Carolina , Riaz Nimrah , Fitzgerald Margaret , Garcia David A. , Carrier Marc , Amos Christopher I. , Flowers Christopher R. , Li Ang 
Published: May 2022

AbstractThe epidemiology of cancer‐associated thrombosis (CAT) among uninsured and vulnerable populations in the US is not well‐characterized. We performed a retrospective cohort study for patients with newly diagnosed cancer from 2011 to 2020 at Harris Health System, which cares for uninsured residents in the Houston metropolitan area. Patient demographics, NCI comorbidity index, area of deprivation index (ADI), cancer histology, staging, and systemic therapy data were extracted. CAT included overall venous thromboembolism (VTE) or pulmonary embolism +/− lower extremity deep vein thrombosis (PE/LE‐DVT) within 1 year of diagnosis. We used multivariable Fine‐Gray models to assess the associations with CAT accounting for death as a competing risk. Among 15 342 patients, 74% were uninsured and 84% lived in socioeconomically disadvantaged neighborhoods. There were 16% Non‐Hispanic White (NHW), 28% Non‐Hispanic Black (NHB), 50% Hispanic (27% Mexican), and 6% Asian/Pacific Islanders (API). The 1‐year CAT incidence rate was 14.6%. Overall VTE was lower for Hispanics versus NHW (SHR 0.87 [0.76–0.99]) and API versus NHW (SHR 0.58 [0.44–0.77]). PE/LE‐DVT was higher for NHB versus NHW (SHR 1.18 [1.01–1.39]). CAT was also associated with chemotherapy‐based regimens (+/− immunotherapy), age, obesity, cancer type/staging, VTE history, and recent hospitalization. NCI comorbidity and ADI scores were associated with mortality but not CAT. In a large cohort of underserved patients with cancer, we identified an elevated incidence of CAT with known and novel risk predictors. Hispanics had lower adjusted rates of CAT and mortality. Our findings highlight the need to investigate and incorporate vulnerable populations in clinical trials.
Transition‐Metal‐Catalyzed Remote C(sp3)−H Functionalization Of Carboxylic Acid And Its Derivatives
Authors: Shahid M. , Banakar Vijay Basavaraj , Prabhakar Ganesh Pothapragada S. K. , Gopinath Purushothaman 
Published: May 2022

AbstractCarboxylic acids are ubiquitous functional groups present in many bio‐relevant molecules, including drugs and amino acids. In general, α‐ and β−C(sp3)−H bonds of carboxylic acids are easy to functionalize, contrary to remote (γ‐ and δ) C−H bonds which are difficult due to the distal location of these C−H bonds from the functional group. On the other hand, functionalizing an inert C(sp3)−H bond is another critical challenge in synthetic chemistry due to its lower acidity and reactivity. Nevertheless, the last decade has witnessed tremendous development in remote sp3‐C−H bond functionalization of carboxylic acid and its derivatives. Here, in this review, we have delineated recent progress in remote γ‐ and δ‐C−H bond functionalization of aliphatic carboxylic acids/amino acids and their derivatives. This review is further subdivided based on the type of functionalization reaction. Finally, we have presented some applications of these methodologies, such as total synthesis of hibispeptin A, etc.
Self‐consistent theory of dynamic melting of a vortex lattice
Authors: Grundberg Staffan , Rammer Jørgen 
Published: May 2022

AbstractThe dynamic melting of vortex lattices in type II superconductors is considered. A field‐theoretic formulation of the pinning problem allows the average over the quenched disorder to be performed exactly. A self‐consistent theory is constructed using a functional method for the effective action, allowing a determination of the pinning force and the vortex fluctuations. The phase diagram for the dynamic melting transition is determined numerically. In contrast to perturbation theory, the self‐consistent theory is in quantitative agreement with the prediction of a recent phenomenological theory and simulations and experimental data.
Rotating cylindrical systems and gravitomagnetism
Authors: Mashhoon B. , Santos N.O. 
Published: May 2022

AbstractWe discuss gravitomagnetism in connection with rotating cylindrical systems. In particular, the gravitomagnetic clock effect is investigated for the exterior vacuum field of an infinite rotating cylinder. The dependence of the clock effect on the parameters of the stationary Lewis metric is determined. We illustrate our results by means of the van Stockum spacetime.
Conductivity of heavily doped Si:P under uniaxial stress
Authors: Waffenschmidt S. , v. Löhneysen H. 
Published: May 2022

AbstractBarely insulating, uncompensated Si:P samples have been tuned through the metal‐insulator transition applying uniaxial stress along the [100] direction. We find a critical exponent μ ≈︂ 1 of the electrical conductivity extrapolated to temperature T = 0, i.e. σ(T → 0,S) ∼ |S — Sc|μ, in disagreement with earlier stress tuning studies along [123‐] where μ ≈︂ 0.5 was reported. Varying the stress or the concentration leads to a different T dependence of σ(T). Our stress‐tuning measurements obey finite‐T scaling with a dynamic exponent z = 3.
Interface of General Relativity, Quantum Physics and Statistical Mechanics: Some Recent Developments
Authors: Ashtekar A. 
Published: May 2022

AbstractThe arena normally used in black holes thermodynamics was recently generalized to incorporate a broad class of physically interesting situations. The key idea is to replace the notion of stationary event horizons by that of ‘isolated horizons.’ Unlike event horizons, isolated horizons can be located in a space‐timequasi‐locally. Furthermore, they need not be Killing horizons. In particular, a space‐time representing a black hole which is itself in equilibrium, but whose exterior contains radiation, admits an isolated horizon. In spite of this generality, the eroth and first laws of black hole mechanics extend to isolated horizons. Furthermore, by carrying out a systematic, non‐perturbative quantization, one can explore the quantum geometry of isolated horizons and account for their entropy from statistical mechanical considerations. After a general introduction to black hole thermodynamics as a whole, these recent developments are briefly summarized.
Exact radiative spacetimes: some recent developments
Authors: Bičák J. 
Published: May 2022

AbstractFive classes of radiative solutions of Einstein's field equations are discussed in the light of some new developments. These are plane waves and their collisions, cylindrical waves, Robinson‐Trautman and type N spacetimes, boost‐rotation symmetric spacetimes and generali ed Gowdy‐type cosmological models.
Strings and black holes
Authors: Damour T. 
Published: May 2022

AbstractI review some recent work (done in collaboration with G. Veneziano) which clarifies the existence of a correspondence between self‐gravitating fundamental string states and Schwarzschild black holes. The main result is a detailed calculation showing that self‐gravity causes a typical string state of mass M to shrink, as the string coupling g2 increases, down to a compact string state whose mass, size, entropy and luminosity match (for the critical value those of a Schwarzschild black hole. This confirms the idea that the entropy of black holes can be accounted for by counting string states, and suggests that the level spacing of the quantum states of Schwarzschild black holes is exponentially small, and very much blurred by radiative effects.
Foundations of Gravitational Lens Theory (Geometry of Light Cones)
Authors: Ehlers J. 
Published: May 2022

AbstractThe main concepts of gravitational lens theory are introduced on the basis of spacetime geometry without assuming approximations. The singularities of light cones, in particular their caustics, are reviewed as examples of singularities of Lagrangian resp. Legendrian maps. It is indicated how the usual approximate lens theory may be derived from the general framework.
An exact gravitational wave solution
Authors: Kramer D. 
Published: May 2022

AbstractAn exact solution describing an axisymmetric gravitational wave propagating in z ‐direction is given in closed form. This solution to Einstein's vacuum field equations has no curvature singularities, in particular it is regular at the symmetry axis. The gravitational wave solution has the nice property that the curvature invariants tend to zero with increasing distance from the axis.
Gravitational Wave Astronomy
Authors: Nollert H.‐P. 
Published: May 2022

AbstractGravitational waves, as predicted by the theory of General Relativity, have been studied theoretically for many decades. However, due to the weak coupling of gravitation with matter, it has not yet been possible to measure them directly. Up to now, we only have indirect evidence of the existence and the effect of gravitational radiation by pulsar timing measurements. New gravitational wave detectors, using laser interferometry, offer the chance of observing gravitational waves directly in the near future, paving the way to a new branch of astronomy, gravitational wave astronomy. In this article, we give a brief review of the techniques which can be used for the detection of gravitational waves, and of the astronomical sources which may emit them, making them candidates for observation through gravitational radiation.
Rotating perfect fluid models in general relativity
Authors: Perjés Z. 
Published: May 2022

AbstractThe various schemes for studying rigidly rotating perfect fluids in general relativity are reviewed. General conclusions one may draw from these are: (i) There is a need to restrict the scope of the possible ansätze, and (ii) the angular behaviour is a valuable commodity. This latter observation follows from a large number of analytic models exhibiting a NUT‐like behaviour. A method of getting around problem (ii) is presented on a simple example. To alleviate problem (i) for rigidly rotating perfect fluids, approximation schemes based on a series expansion in the angular velocity are suggested. A pioneering work, due to Hartle, explores the global properties of matched space‐times to quadratic order in the angular velocity.As a first example of the applications, it is shown that the rigidly rotating incompressible fluid cannot be Petrov type D.
Resolution deterioration in emission electron microscopy due to object roughness
Authors: Nepijko S.A. , Sedov N.N. , Schönhense G. , Escher M. , Bao Xinhe , Huang Weixin 
Published: May 2022

AbstractIn the present paper a general analytic expression has been obtained and confirmed by a computer simulation which links the surface roughness of an object under study in an emission electron microscope and it's resolution. A quantitative derivation was made for the model case when there is a step on the object surface. It was shown that the resolution is deteriorated asymmetrically relative to the step. The effect sets a practical limit to the ultimate lateral resolution obtainable in an emission electron microscope.
Dislocation theory as a 3‐dimensional translation gauge theory
Authors: Lazar Markus 
Published: May 2022

AbstractWe consider the static elastoplastic theory of dislocations in an elastoplastic material. We use a Yang‐Mills type Lagrangian (the teleparallel equivalent of Hilbert‐Einstein Lagrangian) and some Lagrangians with anisotropic constitutive laws. The translational part of the generalized affine connection is utilized to describe the theory of elastoplasticity in the framework of a translation gauge theory. We obtain a system of Yang‐Mills field equations which express the balance of force and moment.