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Among the intricately coupled thermoelectric parameters, carrier effective mass (m*) and carrier density (n) are two key parameters to determine the electrical transport properties. To enhance the broad-temperature thermoelectric performance in n-type PbSe, this work elaborately optimizes its power factor with the intrinsically proportional relationship between carrier effective mass and carrier density, n ∼ (m*)3/2. Herein, the carrier effective mass in n-type PbSe is first optimized with Sn alloying and undergoes a decrease from ∼0.34me in PbSe to ∼0.25me in Pb0.77Sn0.23Se because of band sharpening. This reduced carrier effective mass contributes to an obvious enhancement of carrier mobility, thereby boosting the maximum power factor from ∼16.8 μW cm−1 K−2 in PbSe to ∼20.5 μW cm−1 K−2 in Pb0.85Sn0.15Se. Moreover, to match the reduced carrier effective mass in n-type Pb0.85Sn0.15Se, its carrier density is well tuned with Ag counter doping, which further facilitates a high average power factor in the whole working temperature range. The average power factor in Pb0.85Sn0.15Se systems increases from ∼15.6 μW cm−1 K−2 with a carrier density of ∼6.21 × 1019 cm−3 to ∼17.6 μW cm−1 K−2 with a carrier density of ∼2.12 × 1019 cm−3 at 300–873 K. Finally, an average ZT (ZTave) of ∼0.95 is achieved in the n-type Pb0.85Sn0.15Se sample at 300–873 K, and the sample outperforms most other n-type PbSe-based thermoelectric materials.

Global freshwater shortage has become one of the essential issues and many countries are suffering increasing pressure on their environment. Recently, a large-area graphene nanomesh with microsize pores of 0.45–0.55 nm has been found to achieve a nearly 100% desalination efficacy; however, the development of nanoporous structures with excellent cycling, mechanical and electrical properties remains challenging. Based on density-functional theory, a high-performance stable two-dimensional graphene-based material (Kust-I) with a nanometer pore size of 0.45 nm is cleverly constructed with decagonal, hexagonal, and pentagonal carbon rings. First-principles and classical molecular dynamics simulation results indicate that ten-membered and pentagon rings act in parallel in Kust-I to provide sufficient salt-ion selective adsorption sites and the electron concentration and desalination effect of this material is satisfactory. The mechanical and electronic property results further suggest that the periodic pore structure and electron distribution can effectively overcome the stress concentrations, improve the service life, and produce a self-cleaning effect that facilitates recycling. A potentially facile Kust-I synthesis route was proposed. These findings show the material's tremendous potential in addressing the significant challenge of achieving mechanical stability, long service life, ease of recycling, and large-scale application of current two-dimensional carbon materials.

Intracerebral hemorrhage (ICH) is a devastating disease with the high mortality. The poor outcome of ICH is partially due to a combination of various secondary insults, including in the ischemic area. Xuemaitong capsule (XMT), a kind of traditional Chinese medicine, has been applied to clinic practice. The purpose of this study is to explore the mechanism of XMT in alleviating secondary damage in the ischemic area after ICH. We screened XMT target, compound components, and ICH-related targets using network pharmacology, cluster analysis, and enrichment analysis. We found that the tumor necrosis factor (TNF) signaling pathway might be the key signaling pathway for XMT treatment of ICH. An ICH rat model was established, as demonstrated by poor neurologic score. In the ICH rats, Western blot analysis and immunofluorescence indicated the upregulated expression of TNF receptor 1 (TNFR1), mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), and caspase-3 (CASP3). Importantly, administration of XMT alleviated inflammation, edema, and increased perfusion in the ischemic area, whereas the expression of TNFR1, MAPK, NF-κB, and CASP3 was decreased. Furthermore, Fluoro-Jade B and terminal deoxynucleotidyl transferase–mediated digoxigenin-deoxyuridine nick-end labeling staining revealed that XMT application also inhibited apoptosis and degradation of ischemic area neurons. In conclusion, this evidence elucidates that XMT alleviates neuron apoptosis, ischemic area inflammation, edema, and perfusion through the TNFR1-mediated CASP3/NF-κB/MAPK axis. SIGNIFICANCE STATEMENT Tumor necrosis factor (TNF) is the key signaling pathway of Xuemaitong (XMT) to intervention during intracerebral hemorrhage. Fourteen key targets [intercellular adhesion molecule 1, interleukin (IL) 6, TNF, C-C motif chemokine ligand 2, prostaglandin-endoperoxide synthase 2, v-rel reticuloendotheliosis viral oncogene homolog A, matrix metalloproteinase 9, endothelin-1 (EDN1), mitogen-activated protein kinase (MAPK) 1, fos proto-oncogene protein, caspase-3 (CASP3), jun proto-oncogene, IL1B, MAPK8] are retrieved from the data base. XMT can inhibit neuron apoptosis in the ischemic area via regulating TNF receptor 1 (TNFR1)/CASP3. XMT alleviates inflammation and edema through regulating TNFR1/nuclear factor-κB and TNFR1/MAPK signaling pathways. XMT alleviates hypoperfusion in the cerebral ischemic area through mediating TNFR1/MAPK/EDN1.

Pituitary adenoma is one of the most common intracranial tumors, more and more studies have shown that long non-coding RNA (lncRNA) plays a very important role in pituitary adenoma. However, there are few reports on the function of lncRNA BBOX1-AS1 in pituitary adenomas, and further exploration is needed. The objective of this research is to figure out what function BBOX1-AS1 plays in pituitary adenoma and how it regulates it. The expression of the E2F1, miR-361-3p and BOX1-AS1 genes was measured using a quantitative real-time PCR method. The functional involvement of BBOX1-AS1 in pituitary adenoma was examined utilizing the Transwell assay, western blot assays and the cell counting kit-8. RNA immunoprecipitation and luciferase reporter assays revealed that miR-361-3p binds to E2F1 or BBOX1-AS1. In addition, in-vivo assays were carried out. The expression of BBOX1-AS1 in pituitary adenoma tissues and cells has been increased, according to our findings. Furthermore, it is also noted that downregulation of BBOX1-AS1causes the inhibition of pituitary adenoma cells which result in invasion, apoptosis and proliferation, as well as boosting tumor development in vivo . In addition, BBOX1-AS1 knockdown inhibited tumor development in vivo . We identify BBOX1-AS1 bind to miR-361-3p and to suppress its expression in a negative way. Moreover, miR-361-3p has been shown to bind with E2F1 and inhibit its expression. E2F1 also corrected miR-361-3p-mediated cell invasion, proliferation and apoptosis in BBOX1-AS1-dysregulated pituitary adenoma cells in rescue tests. BBOX1-AS1 increases pituitary adenoma malignant activity by sponging miR-361-3p to upregulate E2F1 expression, which may lead to a new path in pituitary adenoma therapeutic attempts.

Building a safe space for stem cells The meristem, the collection of stem cells that builds plants, is resistant to viral infection. Wu et al. now show that WUSCHEL, a transcription factor that helps to sustain stem cell production in the shoot apical meristem of Arabidopsis , also protects that stem cell domain from viruses. WUSCHEL inhibited viral protein synthesis by repressing methyltransferases that regulate ribosomal RNA processing and ribosome stability. Science , this issue p. 227

Simple strain enhancement Piezoelectric materials are important as sensors and transducers for applications such as ultrasonics. Liu et al. discovered nanopillar regions in a sodium-niobium-oxide film that substantially improve the piezoelectric properties (see the Perspective by Bassiri-Gharb). These nanopillar regions reverse where the cations and anions are located in the crystal structure, with a distinctive boundary in between. This difference in structure results in a strain-sensitive polarity that enhances the piezoelectric properties in a chemically simple material. Science this issue p. 292 ; see also p. 252

The development of a constitutive model of concrete materials under multiaxial forces is an important problem in engineering science, and such a model is the theoretical basis for studying various mechanical behaviors. Based on the Ottosen yield criterion, a cap model parameter is proposed in this paper to describe the yielding behavior of concrete under high hydrostatic pressure; in addition, hardening and softening parameters are considered to reflect the hardening and softening of concrete during the stress state change, thus completely representing the yielding behavior according to the Ottosen criterion. A nonassociative flow rule for the Ottosen yield criterion is established to accurately calculate the strain change of concrete specimens and describe the expansion of concrete. The calculation is performed based on the established constitutive model, and the calculated results are compared with the results of uniaxial, biaxial, triaxial compression and uniaxial tension experiments on normal- and high-strength concrete. The comparison results show that the calculated stress–strain curves are in agreement with the experimental data. Hence, the proposed model can explain the stress–strain relationship and strength characteristics of concrete at different strengths.

Identification of rotating sources with non-uniform directivity has been paid much attention in the field of aeroacoustic measurements over recent years. Singularities may be produced on the source map by using the rotating source identifier based on the multipole model due to zeros of the directivity function. A correction method is proposed to remove the influence of source directivity on source imaging and restrain the singular problem. De-Dopplerized microphone signals are transformed to the frequency domain and deconvolved with transfer functions to compensate for directivity functions. Numerical simulations, as well as experiments using rotating dipole loudspeakers, were conducted to verify the proposed method. It is demonstrated that the method is suitable for rotating sources with arbitrary orientation and works well under a high level of background noise. Positions and strengths of sources are estimated more accurately than traditional algorithms.

In noisy environments, the acoustic wave is complicated and consists of the radiated wave, the incident wave, as well as its scattering wave. Double-layered pressure measurement is introduced to the boundary element method based near field acoustic holography to recover the free field quantities. First, the incoming and outgoing propagation waves are separated by exploring the propagation property of the two waves from their source to the field with the boundary integral equation. Subsequently, the scattering wave is filtered out by considering the boundary condition of the vibrating structure. Further, a measurement on an enclosing hologram is adopted to accurately reconstruct the distribution of normal velocity on the boundary. Two sets of the system of linear equations are built on the double-layered measurements. The Schur complement equation is then applied in conjunction with the Tikhonov regularization method to obtain an optimized reconstruction. Numerical examples are set up for two representative radiators impinged by incident waves. It is demonstrated that the free field normal velocity can be correctly reconstructed even if the signal-to-noise ratio is negative. An experiment is conducted for the cubic radiator to verify the accuracy and potential for the practical reconstruction in a noisy environment.

Nanoscale phase mixtures in transition-metal oxides (TMOs) often render these materials susceptible to external stimuli (electric field, mechanical stress, etc.), which can lead to rich functional properties and device applications. Here, direct observation and multifield manipulation of a nanoscale mixture of brownmillerite SrFeO

Crystalline SnSe has been revealed as an efficient thermoelectric candidate with outstanding performance. Herein, record-high thermoelectric performance is achieved among SnSe crystals via simply introducing a small amount of SnSe2 as a kind of extrinsic defect dopant. This excellent performance mainly arises from the largely enhanced power factor by increasing the carrier concentration high as 6.55 × 1019 cm-3, which was surprisingly promoted by introducing extrinsic SnSe2 even though pristine SnSe2 is an n-type conductor. The optimized carrier concentration promotes a deeper Fermi level and activates more valence bands, leading to an extraordinary room-temperature power factor ∼54 μW cm-1 K-2 through enlarging the band effective mass and Seebeck coefficient. As a result, on the basis of simultaneously depressed thermal conductivity induced from both Sn vacancies and SnSe2 microdomains, maximum ZT values ∼0.9-2.2 and excellent average ZT > 1.7 among the working temperature range are achieved in Na doped SnSe crystals with 2% extrinsic SnSe2. Our investigation illustrates new approaches on improving thermoelectric performance through introducing defect dopants, which might be well-implemented in other thermoelectric systems.

To provide alternative battery technologies to lithium ion battery, multivalent metal ion batteries with their high theoretical capacities and ease of preparation have gradually gained attention from both academia and industries. In this work, we report bismuth ion battery (BIB) as a promising trivalent metal ion battery, next to the only known aluminum ion battery. Our BIB successfully demonstrates battery behavior with discharge plateaus at 0.5 and 0.2 V. Gravimetric capacity of 300 mAh g-1 at current density of 0.2 A g-1 was obtained with ca. 98% coulombic efficiency. In addition, stable cyclic life was achieved after 100 cycles at 0.3 A g-1 which further suggests its suitability as potential trivalent metal ion battery.

Objective To determine the clinical value of 18F-FDG-PET/CT and dual-energy virtual noncalcium CT to detect and identify single osteolytic metastases (SOM) in participants with non-small cell lung cancer (NSCLC). Materials and Methods Forty-two participants (mean age, 63.5 years ± 10.1; range, 41–81 years) with suspected SOM diagnosed by whole-body 18F-FDG-PET/CT underwent non-enhanced dual-energy CT. All images were visually and quantitatively evaluated by two nuclear medicine physicians (R1 and R2) and two radiologists (R3 and R4) independently. The results of visual and quantitative analysis of 18F-FDG-PET/CT and dual-energy CT were compared with pathological results. Results In the visual analysis, the specificity and positive predictive value of dual-energy CT for reader 1 and reader 2 is larger than the corresponding figures of18F-FDG-PET/CT for reader 3 and reader 4 (94.1% each vs 82.4%/76.5%; 95.2%/95.0% vs 88.9%/86.2%). The sensitivity and negative predictive value of dual-energy CT is relatively lower than the number of 18F-FDG-PET/CT for readers (80.0%/76.0% vs 96.0%/100.0%; 76.2%/72.7% vs 93.3%/100.0%, respectively). ROI-based analysis of SUVmax on PET/CT images and CT numbers on VNCa images showed a significant difference between metastases and non-metastases (P Conclusions Pre-surgical evaluation by combination of whole-body 18F-FDG-PET/CT and dual-energy CT could improve the classification of SOM and may further guide the surgical decision-making in participants with NSCLC.

The metallic elements with a small atomic radius can not only compensate for the intrinsic vacancies to improve the carrier mobility, but also can form interstitials to reduce lattice thermal conductivity. In this work, we investigate the contrasting roles of three different metallic elements with small atomic radius on the thermoelectric properties of n-type PbM0.01Se (M = Cu, Zn, Ni). We find that all the metallic elements can increase the carrier concentration as electron donors and improve the electrical transport properties. In addition, the lattice thermal conductivity of PbSe can be significantly decreased through the formation of interstitials by the incorporated extra metallic elements. We also find that the PbCu0.01Se sample exhibits a unique and complex behavior compared with the other samples due to the diffusion and the thermally activated oxidation of Cu+ ions. When the temperature increased to 673 K, the carrier concentration of PbCu0.01Se sample increases suddenly and continues to increase by nearly two folds, which we ascribe to the release of 3d orbital electrons in Cu+ ions. This results in a strong decoupling of the charge and heat transport in the material, which can be manifested by the overestimation of the electronic thermal conductivity when assuming strong electron–phonon coupling in Wiedemann–Franz law. A maximum ZT of ∼1.6 can be reached at 773 K and the average ZT of ∼0.96 can be achieved in PbCu0.01Se. Our results demonstrate the exceptional contrasting behavior of Cu in PbSe by comparing with Zn and Ni, and the thermoelectric performance of n-type PbSe can be enhanced through the introduction of extra metallic elements with small radius.

In conventional delay-and-sum beamforming, the monopole source assumption may cause a dipole source to be misinterpreted, leading to incorrect mapping results. A dipole-based beamforming method is proposed that is an extension of monopole-based conventional beamforming. The dipole sources could be located with no prior knowledge of the source orientation, and the unknown orientation is arbitrary in a three-dimensional domain. The location of a dipole source is determined by calculating the beamforming results at predefined orientations and positions using a dipole-based propagation function, and the final beamforming result at each scanning point is determined by the maximum value at the predefined orientations. Numerical simulations and experiments are performed on rotating dipole sources, and satisfactory results for the location of these dipole sources are obtained with different orientations.

In the field of warhead design, non-cylindrical warhead, especially elliptical cross-section warhead, has received considerable attention. In this study, the initial velocity and distribution characteristics of the preformed fragments of a columnar projectile with an elliptical cross-section were examined. To obtain the velocity distribution of the fragments in this kind of projectile, three elliptical cross-section projectiles with different geometric sizes were test based on the static detonation tests. Then, the numerical models of the elliptical cross-section projectile have been established and validated according to the experiment results. Besides, two kinds of initiation types were studied by the simulation model, and the results indicate that not only the geometric size but the initiation type do great influences on the fragment velocity distribution in the direction of the axis. An empirical model was proposed based on the fragment two-step acceleration progress, and it was in good accordance with numerical results.

Inspiratory flow limitation means that when the flowrate reaches a certain value, it no longer increases, or even decreases, which is called negative effort dependence flow limitation, even if the inspiration effort is increased. This occurs often in obstructive sleep apnea patients, but its mechanism remains unclear. To reveal the mechanism of inspiratory flow limitation, we constructed a unique partially collapsible in-vitro upper airway model of obstructive sleep apnea patients to observe the change of airway resistance with inspiratory driving pressure. The important findings demonstrate that with the increase of inspiratory effort, the driving pressure increases faster than the airway resistance in the early stages, and then the reverse occurs as the airway becomes narrower. The airway collapse caused by the transmural pressure can lead to a rapid increase in downstream resistance with the increase of inspiratory effort, which is the key reason causing the flow reduction and the formation of typical negative effort dependence flow limitation. The mechanical mechanism revealed in this study will lead to fully new insights into the study and treatment of obstructive sleep apnea.

To explore the cumulative damage law of near-field underwater explosions on the side of the ship structure, the multi-cabin model of the shipboard local structure is designed and applied to close-in underwater explosion experiments with different explosive masses and model conditions. The pressure load of the explosion shock wave near the water surface is obtained and analyzed. The damage results, such as the damage pattern of the model and the damage range of cabins, are acquired. The comprehensive comparison shows that: the secondary explosion on the side has a significant cumulative damage effect; the damage pattern of the structure is closely related to the proportional distance of the explosion. The damaged power of a single large charge explosion on the shipboard is bigger than the cumulative damage caused by two small explosions. The results of this study can provide a reference for the research on the damage and protection of the ship.

Polyurea is widely employed as a protective coating in many fields because of its superior ability to improve the anti-blast and anti-impact capability of structures. In this study, the mechanical properties of polyurea XS-350 were investigated via systematic experimentation over a wide range of strain rates (0.001–7000 s−1) by using an MTS, Instron VHS, and split-Hopkinson bars. The stress-strain behavior of polyurea was obtained for various strain rates, and the effects of strain rate on the primary mechanical properties were analyzed. Additionally, a modified rate-dependent constitutive model is proposed based on the nine-parameter Mooney-Rivlin model. The results show that the stress-strain curves can be divided into three distinct regions: the linear-elastic stage, the highly elastic stage, and an approximate linear region terminating in fracture. The mechanical properties of the polyurea material were found to be highly dependent on the strain rate. Furthermore, a comparison between model predictions and the experimental stress-strain curves demonstrated that the proposed model can characterize the mechanical properties of polyurea over a wide range of strain rates. Keywords: Polyurea, Strain rate effect, Dynamic mechanical properties, Constitutive model

In this paper, using the first-order Nedelec conforming edge element space of the second type, we develop and analyze a continuous interior penalty finite element method (CIP-FEM) for the time-harmonic Maxwell equation in the three-dimensional space. Compared with the standard finite element methods, the novelty of the proposed method is that we penalize the jumps of the tangential component of its vorticity field. It is proved that if the penalty parameter is a complex number with negative imaginary part, then the CIP-FEM is well-posed without any mesh constraint. The error estimates for the CIP-FEM are derived. Numerical experiments are presented to verify our theoretical results.

Oxide nanosprings have attracted many research interests because of their anticorrosion, high-temperature tolerance, oxidation resistance, and enhanced-mechanic-response from unique helix structures, enabling various applications like nanomanipulators, nanomotors, nanoswitches, sensors, and energy harvesters. However, preparing oxide nanosprings is a challenge for their intrinsic lack of elasticity. Here, an approach for preparing self-assembled, epitaxial, ferroelectric nanosprings with built-in strain due to the lattice mismatch in freestanding La

A large electromechanical response in ferroelectrics is highly desirable for developing high-performance sensors and actuators. Enhanced electromechanical coupling in ferroelectrics is usually obtained at morphotropic phase boundaries requiring stoichiometric control of complex compositions. Recently it was shown that giant piezoelectricity can be obtained in films with nanopillar structures. Here, we elucidate its origin in terms of atomic structure and demonstrate a different system with a greatly enhanced response. This is in non-stoichiometric potassium sodium niobate epitaxial thin films with a high density of self-assembled planar faults. A giant piezoelectric coefficient of ∼1900 picometer per volt is demonstrated at 1 kHz, which is almost double the highest ever reported effective piezoelectric response in any existing thin films. The large oxygen octahedral distortions and the coupling between the structural distortion and polarization orientation mediated by charge redistribution at the planar faults enable the giant electric-field-induced strain. Our findings demonstrate an important mechanism for realizing the unprecedentedly giant electromechanical coupling and can be extended to many other material functions by engineering lattice faults in non-stoichiometric compositions.

Immunotherapy has led to an expansion of the treatment of malignancies, but its effect in prostate cancer (PCa) patients is modest. Chemoimmunotherapy is a promising approach that has attracted substantial attention. Although the widely used clinical chemotherapeutic drug doxorubicin (DOX) elicits immunogenic cell death (ICD), its weak ICD effect and the abnormal vasculature of tumors severely limit its efficacy in chemoimmunotherapy. Ingenol-3-angelate (I3A), an emerging antitumor drug with dual chemotherapeutic and immune response-eliciting effects, is expected to exert synergistic effects when administered in combination with DOX. I3A induces the ICD of PCa cells by triggering mitophagy and apoptosis and promotes the normalization of tumor vessels, resulting in sufficient infiltration of immune cells into tumors. A synergistic effect of I3A and DOX was observed in vitro at a molar ratio of 1:4. To codeliver this ratio of I3A and DOX to tumor and ensure their uptake, we designed a dual-targeting delivery system, polylactide-poly(ethylene) glycol-2-(3-((S)-5-amino-1-carboxypentyl)-ureido) pentanedioate/triphenylphosphonium (PLA-PEG-ACUPA/TPP), which targets prostate-specific membrane antigen (PSMA) and mitochondria. Delivery of these nanomedicines led to inhibited tumor growth and a strong antitumor immune response. This study sheds light on the mitophagic and antiangiogenic mechanisms underlying I3A treatment of PCa and provides a strategy for combining vascular normalization and chemoimmunotherapy for PCa treatment., Graphical abstract Image 1

This study aims to assess the diagnostic performance of dual-energy computed tomography (DECT) on lumbar paravertebral muscles fat infiltration (PMFI) in participants with low back pain (LBP).In this prospective study, 21 participants with LBP were performed with noncontrast DECT scans within 1 week after magnetic resonance (MR) examinations. The assessment was based on the selected region of interest obtained from the paravertebral L1/L2-L5/S1 muscle. On visual evaluation, PMFI was assessed at DECT virtual monoenergetic images (80 keV) with Goutallier classification system using MR results as a reference. Quantitative parameters fat fraction, CT number, ΔCT number (difference of CT number at 140 and 80 keV), and optimal cutoff values above the indicators between MR adjacent grades were measured.In this study, 582 ROIs from 21 participants (mean age, 60 ± 16 years old; 15 females) were evaluated. Sensitivity, specificity, and accuracy of readers 1 and 2 at severe grade (grades 3 and 4) were 67% and 85% (22 and 28 of 33), 99% and 99% (159 and 160 of 161), and 93% and 97% (181 and 188 of 194), respectively. Interobserver reliability was high with κ = 0.85 (p 0.001). For DECT quantification parameters, significance was all represented between five grades (all p 0.01). The area under the curve of indicators for discrimination between severe (grades 3 and 4) and normal and moderate (grades 0, 1, and 2) grades were 0.80 (p 0.001).DECT was a promising qualitative and quantitative imaging technique to assess lumbar PMFI in participants with LBP and could provide accurate quantification for different fat infiltration (FI) degrees. Moreover, visual DECT assessment could excellently distinguish severe from normal and moderate FI of MR grades.

In thermoelectrics, the material's performance stems from a delicate tradeoff between atomic order and disorder. Generally, dopants and thus atomic disorder are indispensable for optimizing the carrier concentration and scatter short-wavelength heat-carrying phonons. However, the strong disorder has been perceived as detrimental to the semiconductor's electrical conductivity owing to the deteriorated carrier mobility. Here, we report the sustainable role of strong atomic disorder in suppressing the detrimental phase transition and enhancing the thermoelectric performance in GeTe. We found that AgSnSe

Oxide nano-springs have attracted many research interests because of their anti-corrosion, high-temperature tolerance, oxidation resistance, and enhanced-mechanic-response from unique helix structures, enabling various nano-manipulators, nano-motors, nano-switches, sensors, and energy harvesters. However, preparing oxide nano-springs is a challenge for their intrinsic nature of lacking elasticity. Here, we developed an approach for preparing self-assembled, epitaxial, ferroelectric nano-springs with built-in strain due to the lattice mismatch in freestanding La0.7Sr0.3MnO3/BaTiO3 (LSMO/BTO) bilayer heterostructures. We find that these LSMO/BTO nano-springs can be extensively pulled or pushed up to their geometry limits back and forth without breaking, exhibiting super-scalability with full recovery capability. The phase-field simulations reveal that the excellent scalability originates from the continuous ferroelastic domain structures, resulting from twisting under co-existing axial and shear strains. In addition, the oxide hetero-structural springs exhibit strong resilience due to the limited plastic deformation nature and the built-in strain between the bilayers. This discovery provides an alternative way for preparing and operating functional oxide nano-springs that can be applied to various technologies.

Multitudinous topological configurations spawn oases of many physical properties and phenomena in condensed-matter physics. Nano-sized ferroelectric bubble domains with various polar topologies (e.g., vortices, skyrmions) achieved in ferroelectric films present great potential for valuable physical properties. However, experimentally manipulating bubble domains has remained elusive especially in the bulk form. Here, in any bulk material, we achieve self-confined bubble domains with multiple polar topologies in bulk Bi

The increase of the urban population and the expansion of the urban scale generate a large number of residents’ travel demand, which brings great pressure to the urban public transport system. As a new supplementary mode of urban public transport, virtual guided train transportation system will help to improve travel problem of residents. In the operation process, the virtual guided transportation system will face all kinds of unexpected situations, which will cause the sudden gathering of large-scale passenger flow. Therefore, it is of great practical significance to study the organization scheme of virtual guided train transportation under sudden large passenger flow. Based on the analysis of the characteristics of the virtual guided train transportation system and sudden large passenger flow, this paper puts forward the setting of emergency turn back station for virtual guided transportation system, emergency routing, emergency stop and technical scheme for collaborative organization of virtual oriented transportation system and conventional public transportation under sudden large passenger flow. Finally, Yibin smart rail line T1 is selected for analysis.

To date, thermoelectric performance has been enhanced through improving the power factor and/or reducing the lattice thermal conductivity. Here, we report an effective method of boosting thermoelec...

Integrating multiple properties in a single system is crucial for the continuous developments in electronic devices. However, some physical properties are mutually exclusive in nature. Here, we report the coexistence of two seemingly mutually exclusive properties-polarity and two-dimensional conductivity-in ferroelectric Ba$_{0.2}$Sr$_{0.8}$TiO$_3$ thin films at the LaAlO$_3$/Ba$_{0.2}$Sr$_{0.8}$TiO$_3$ interface at room temperature. The polarity of a ~3.2 nm Ba$_{0.2}$Sr$_{0.8}$TiO$_3$ thin film is preserved with a two-dimensional mobile carrier density of ~0.05 electron per unit cell. We show that the electronic reconstruction resulting from the competition between the built-in electric field of LaAlO$_3$ and the polarization of Ba$_{0.2}$Sr$_{0.8}$TiO$_3$ is responsible for this unusual two-dimensional conducting polar phase. The general concept of exploiting mutually exclusive properties at oxide interfaces via electronic reconstruction may be applicable to other strongly-correlated oxide interfaces, thus opening windows to new functional nanoscale materials for applications in novel nanoelectronics., Comment: Main text: 25 pages, 4 figures Supplementary note: 19 pages, 11 figures