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Graphene oxide is attractive in flexible materials due to its biocompatibility. Herein, flexibility of graphene oxide under uniaxial tensile strain has been studied in term of the bending modulus. It is demonstrated that tensile strain plays an effective role in softening the bending modulus of graphene oxide. The strained graphene oxide can be even more flexible than graphene. The mechanism of strain softened bending modulus is discussed where weakened atomic bonding accounts directly for the enhanced flexibility. Particularly, an important factor for softened bending modulus is proposed, i.e. alignment of epoxide groups. The degradation of bending modulus is more prominent when the epoxides are aligned along the bending direction. This work not only proposes an effective method to enhance the flexibility of graphene oxide, but also unveils the mechanism of softened bending modulus, which could be useful in design of highly flexible materials.

Lateral buckling is a severe phenomenon that takes place in reinforced concrete structural walls under severe seismic action and can lead to total collapses. One critical mechanical parameter affecting the lateral buckling phenomenon is the degree of tensile strain that the wall boundary edges have been subjected to during the cyclic loading of seismic action. This phenomenon is studied here for the first time for such a large degree of elongation, modelling a severe seismic action leading to the appearance of out-of-plane buckling. The study herein involves a tensile strain equal to 60‰. Afterwards, compression loading is applied until failure. A prism specimen is used to model the boundary edges—a practice well established worldwide. Useful conclusions arise from the application of such a large degree of tensile strain. [ABSTRACT FROM AUTHOR]

The improved electrocatalytic activity towards oxygen electrode reactions in lithium-oxygen batteries of NiFe-based bimetal-organic frameworks with certain internal tensile strain is realized via a simple organic linker scission strategy. The introduced tensile strain broadens the inherent interatomic distances, leading to an upshifted d-band center of metal nodes in MOFs, and thus the enhancement of the adsorption strength of catalysts surface towards intermediates, and increasing the reaction activity for oxygen electrode in lithium-oxygen batteries. [Display omitted] Developing effective electrocatalyst and fundamentally understanding the corresponding working mechanism are both urgently desired to overcome the current challenges facing lithium-oxygen batteries (LOBs). Herein, a series of NiFe-based bimetal-organic frameworks (NiFe-MOFs) with certain internal tensile strain are fabricated via a simple organic linker scission strategy, and served as cathode catalysts for LOBs. The introduced tensile strain broadens the inherent interatomic distances, leading to an upshifted d-band center of metallic sites and thus the enhancement of the adsorption strength of catalysts surface towards intermediates, which is contributed to rationally regulate the crystallinity of discharge product Li 2 O 2. As a result, the uniformly distributed amorphous film-like Li 2 O 2 tightly deposits on the surface of strain-regulated MOF, resulting in excellent electrochemical performance of LOBs, including a large discharge capacity of 12317.4 mAh g−1 at 100 mA g−1 and extended long-term cyclability of 357 cycles. This work presents a novel insight in adjusting the adsorption strength of cathode catalysts towards intermediates via introducing tensile strain in catalysts, which is a pragmatic strategy for improving the performance of LOBs. [ABSTRACT FROM AUTHOR]

Conventional silicon-based transistor downscaling is approaching its physical limits, and thus additional novel solutions are urgently desired to address this issue. Herein, we show that 2-D antimonene with heavy effective mass and high density of state (DOS) via strain engineering presents reliable transistor performance with the channel length (${L}_{\text {ch}}$) shrinking below 5 nm. As the biaxial tensile strain increases to 7%, the band switching gives rise to a heavy hole effective mass of $12.6{m}_{{0}}$ and a Van Hoff singularity-like DOS. This unique electronic structure can effectively suppress the tunneling current, resulting in steep subthreshold swings (SSs) and ideal ON-current (${I}_{ \mathrm{ON}}$). Especially, as ${L}_{\text {ch}}$ downscales to 2.2 nm, the OFF-current can be easily reduced to 0.1 $\mu \text{A}/\mu \text{m}$ with SS of 120 mV/dec (310 mV/dec for pristine antimonene) and ${I}_{ \mathrm{ON}}$ exceeds 900 $\mu \text{A}/\mu \text{m}$ , fulfilling the requirements for high-performance applications. Our results provide new insights on extending the scaling limit in energy-efficient gate-controlled devices. [ABSTRACT FROM AUTHOR]

In this letter, we comprehensively investigate the electrical properties of the 1200 V planner-gate 4H-SiC power metal–oxide–semiconductor field-effect transistors under the mechanical strains. Three kinds of strains, including the biaxial strain, uniaxial strain parallel to the gate channel, and uniaxial strain perpendicular to the gate channel, are applied using the wafer bending system. It is found that all kinds of compressive strains improve the drain current (Id) under the same gate voltage (Vg) and shift the threshold voltage (Vth) negatively, while the tensile strains decrease Id and shift Vth positively. The Vth shift mainly results from the strain modulated band structure in the poly-Si gate. Under the same overdrive gate voltage (Vov), biaxial strains merely change Id, while both the parallel and perpendicular uniaxial compressive strains enhance Id. The uniaxial compressive strain elevates the electron mobility in the inverted channel by repopulating more electrons into the valleys with a smaller conduction effective mass, which results in the current improvement. [ABSTRACT FROM AUTHOR]

It is important and difficult to improve the tensile strength of backfill material to ensure the stability of goafs. In this study, rice straw (RS) in fiber form is used to improve the tensile properties of cemented paste backfill (CPB). An orthogonal experiment was designed, Brazilian indirect tensile strength tests were conducted to test the tensile performance of RS fiber-reinforced cemented paste backfill (RSCPB) under different fiber content (1, 2, 3 kg/m3) and fiber length (0.8~1, 1~3, 3~5 cm), and the microstructure of RSCPB was analyzed with scanning electron microscopy (SEM). The results showed that, compared with the conventional cemented paste backfill (CCPB), the increase in tensile strength of RSCPB ranged from 115.38% to 300.00% at 3 days curing age, 40.91% to 346.15% at 7 days, and −38.10% to 28.00% at 28 days, and the strain was slightly reduced during the curing period. The tensile strength, strain, and percentage increase of the RSCPB compared to the CCBP did not show a monotonic pattern of variation with the RS fiber content and length during the curing period. The RSCPB samples fractured under peak stress, showing obvious brittle failure. In addition, sulfate generated from S2− in the tailings inhibits the hydration reaction, and generates swelling products that form weak structural surfaces, which, in turn, lead to a 28-day tensile strength and strain of RSCPB lower than those at 7 days. [ABSTRACT FROM AUTHOR]

This study used a digital imaging technique (DIC) to obtain the strain distribution at various locations in undermatching X80 pipe girth-weld joints under uniaxial tensile loading. In addition, the microstructure characteristics and deformation patterns in different regions were analyzed by scanning electron microscopy (SEM). The results showed that there was strain heterogeneity between the various regions of the welded joint. Strain concentration existed only in the 12.8 mm base metal heat-affected zone (HAZ) and only in the elastic deformation stage. There was strain concentration in the weld metal (WM) and both sides of the HAZ close to the near-fracture stage, and the maximum deformation was in the WM. When εM = 12.2%, the KC was 6.27 and the KF was 1.73, and the KF was 113% and 152% of the KC and the KG, respectively. The large number of slip strips generated indicated serious damage in the WM near the fracture stage. In the elastic deformation stage, the strain concentration of the N1 HAZ was caused by the softened ferrite. The maximum deformation of the WM near the fracture stage was caused by the large grain size and the non-uniform martensite–austenite (M–A) islands, which may also lead to better local toughness of the cover weld and further affect the fracture mechanism of the welded joint.

Despite widely used as a commercial cathode, the anisotropic 1D channel hopping of lithium ions along the [010] direction in LiFePO 4 prevents its application in fast charging conditions. Herein, an ultrafast nonequilibrium high-temperature shock technology is employed to controllably introduce the Li-Fe antisite defects and tensile strain into the lattice of LiFePO 4 . This design makes the study of the effect of the strain field on the performance further extended from the theoretical calculation to the experimental perspective. The existence of Li-Fe antisite defects makes it feasible for Li + to move from the 4a site of the edge-sharing octahedra across the ab plane to 4c site of corner-sharing octahedra, producing a new diffusion channel different from [010]. Meanwhile, the presence of a tensile strain field reduces the energy barrier of the new 2D diffusion path. In the combination of electrochemical experiments and first-principles calculations, the unique multiscale coupling structure of Li-Fe antisite defects and lattice strain promotes isotropic 2D interchannel Li + hopping, leading to excellent fast charging performance and cycling stability (high-capacity retention of 84.4% after 2000 cycles at 10 C). The new mechanism of Li + diffusion kinetics accelerated by multiscale coupling can guide the design of high-rate electrodes., (© 2024 Wiley‐VCH GmbH.)

In this perspective article, we discuss the application of ion implantation to manipulate strain (by either neutralizing or inducing compressive or tensile states) in suspended thin films. Emphasizing the pressing need for a high-mobility silicon-compatible transistor or a direct bandgap group-IV semiconductor that is compatible with complementary metal-oxide-semiconductor technology, we underscore the distinctive features of different methods of ion beam-induced alteration of material morphology. The article examines the precautions needed during experimental procedures and data analysis and explores routes for potential scalable adoption by the semiconductor industry. Finally, we briefly discuss how this highly controllable strain-inducing technique can facilitate enhanced manipulation of impurity-based spin quantum bits (qubits)., (Creative Commons Attribution license.)

Moisture in unbound layers and temperature in asphalt layers affect the structural response of pavements, such as the tensile strain at the bottom of asphalt concrete layers. Previous studies have proposed relationships for estimating tensile strain at the bottom of an asphalt layer from Falling Weight Deflectometer (FWD) surface deflection measurements. These relationships have been developed based on theoretical calculations of strains and surface deflections. The main objective of this study was to evaluate these relationships using measured FWD deflections and tensile strains at the bottom of asphalt concrete layers. Three instrumented test structures were considered in the study. FWD and strain measurements were conducted at varying groundwater levels in the subgrade and temperatures in the asphalt concrete layers. The results revealed that the relationships have poor agreement with measured strains. A new relationship is proposed that incorporates the volumetric water content in the subgrade and the temperature in the asphalt layers in addition to the surface FWD deflections. [ABSTRACT FROM AUTHOR]

Almost all proposed configurations and practical achievements based on superconductor/ferromagnet (S/F) heterostrucutres focus on s-wave superconductors. However, several attempts targeted also high temperature superconductors, most of them using manganite ferromagnets LaXMnO3 (X: Ca or Sr) and Y1Ba2Cu3O7âˆ' x (YBCO). Here we propose a new ferromagnetic material that can be used with YBCO for the fabrication of S/F hybrid structures. We show that a ferromagnetic order can be induced in a thin layer (∼130 nm thickness) of CaRuO3 grown by pulsed laser deposition on epitaxial YBCO film. Detailed magnetic and structural investigations show that the observations of the weak ferromagnetism are consistent with the magnetic order induced by in-plane tensile strain of about 1.7% and the easy-magnetization axis forms an angle of ∼180Âş with the layer plane. The value of the Curie temperature T Curie estimated using the Curieâ€"Weiss law was 340 K. An unusual temperature dependence of the magnetic moment around the superconducting transition was observed in both field-cooled and zero-field-cooled configurations which is attributed to the paramagnetic Meissner effect. [ABSTRACT FROM AUTHOR]

Almost all proposed configurations and practical achievements based on superconductor/ferromagnet (S/F) heterostrucutres focus on s-wave superconductors. However, several attempts targeted also high temperature superconductors, most of them using manganite ferromagnets LaXMnO3 (X: Ca or Sr) and Y1Ba2Cu3O7âˆ' x (YBCO). Here we propose a new ferromagnetic material that can be used with YBCO for the fabrication of S/F hybrid structures. We show that a ferromagnetic order can be induced in a thin layer (∼130 nm thickness) of CaRuO3 grown by pulsed laser deposition on epitaxial YBCO film. Detailed magnetic and structural investigations show that the observations of the weak ferromagnetism are consistent with the magnetic order induced by in-plane tensile strain of about 1.7% and the easy-magnetization axis forms an angle of ∼180Âş with the layer plane. The value of the Curie temperature T Curie estimated using the Curieâ€"Weiss law was 340 K. An unusual temperature dependence of the magnetic moment around the superconducting transition was observed in both field-cooled and zero-field-cooled configurations which is attributed to the paramagnetic Meissner effect. [ABSTRACT FROM AUTHOR]

Electrochemical hydrogenation (ECH) uses electricity to drive proton (H+) reduction for hydrogenation, which can greatly reduce energy supply and environmental pollution, representing an ideal alternative to traditional thermal hydrogenation. In this work, we put forward tensile‐strained PdRuCu alloy to promote ECH. Tensile strain promotes the adsorption of C=C by changing the d‐band center. Meanwhile, alloying Ru and Cu into Pd lattice facilitates hydrogenation by weakening Pd−H bonding. Therefore, PdRuCu icosahedra display excellent ECH performance of 2‐methyl‐3‐buten‐2‐ol (MBE) with specific activity of 227.4 μmolMBE nm−2 min−1 at −0.3 V versus reversible hydrogen electrode (RHE), about 16.1 and 10.5 times higher than that of commercial Pd/C and Ru/C, respectively. In addition, PdRuCu icosahedra was excellent in the scaling up of substrate concentration combined with anisyl alcohol oxidation to produce high‐value added anisaldehyde at anode. This work provides a guideline for the rational design of highly active and durable metallic catalyst in ECH. [ABSTRACT FROM AUTHOR]

An asphalt-binder is one of the key constituent elements that significantly influences and controls the fracture behavior and cracking performance of hot-mix asphalt (HMA). In particular, the low-temperature rheological properties of asphalt-binders are critical in terms of improving the HMA fracture properties in the laboratory and ultimately mitigating cracking in the field. The bending beam rheometer (BBR) is one of the most widely used laboratory test methods for evaluating and quantifying the asphalt-binder behavior at low temperatures, mostly using the stiffness (S) and m-value parameters. Using the Texas flexible pavements and overlays database, namely, the Texas data storage system (DSS), as the primary data source, this study was conducted to correlate the asphalt-binder low-temperature rheological properties (measured using the BBR) to the HMA fracture properties. The HMA fracture properties were measured in the laboratory using the monotonic-loading overlay tester (ML-OT). In general, the asphalt-binder low-temperature rheological properties [particularly the stiffness (S)] exhibited promising potential to predict the HMA fracture properties, namely, the tensile strain (εt) and fracture energy index (FE Index), with a coefficient of determination (R2) greater than 60%. [ABSTRACT FROM AUTHOR]

In this work, VO2 based thermal sensing thin film synthesized on flexible muscovite substrates by direct oxidation of deposited vanadium metal, were investigated for the impact of doping and strain on their electrical properties. We investigated both undoped and Ti doped VO2 on muscovite substrate and compared with those on Quartz substrate. Both doped and undoped VO2 were found to undergo phase transition due to effect of heat as well as mechanical strain on muscovite substrate. On the other hand, the Ti doped VO2, on both quartz and muscovite substrate showed significant reduction in the transition temperature compared to the undoped VO2 thin films on these two substrates. When subjected to mechanical strain, the VO2 thin film on muscovite substrates resulted in a decrease or an increase in resistance depending on whether the applied strain was tensile or compressive, respectively. The resistance change was also steeper around the transition temperature compared to room temperature, exhibiting high gauge factor. This metal doped VO2 on flexible muscovite substrate has the significantly low transition temperature which causes the VO2 film to undergo phase transition at a near-room temperature and enables it to be used as a temperature sensor with enhanced sensitivity.

With the ever-increasing interest in low-dimensional materials, it is urgent to understand the effect of strain on these kinds of structures. In this study, taking the CF2Si monolayer as an example, a computational study was carried out to investigate the effect of tensile shear strain on this compound. The structure was dynamically and thermodynamically stable under ambient conditions. By applying tensile shear, the structure showed a strain-driven transition from a semiconducting to a metallic behavior. This electronic transition’s nature was studied by means of the electron localization function index and an analysis of the noncovalent interactions. The result showed that the elongation of covalent bonds was not responsible for this metallization but rather noncovalent interactions governing the nonbonded bonds of the structure. This strain-tuned behavior might be capable of developing new devices with multiple properties involving the change in the nature of chemical bonding in low-dimensional structures.

We investigated the production conditions and optoelectrical properties of thin film material consisting of regularly ordered core/shell Ge/Al and Ge/Si3N4/Al quantum dots (QDs) in an alumina matrix. The materials were produced by self–assembled growth achieved by means of multilayer magnetron sputtering deposition. We demonstrated the successful fabrication of well-ordered 3D lattices of Ge/Al and Ge/Si3N4/Al core/shell quantum dots with a body-centred tetragonal arrangement within the Al2O3 matrix. The addition of shells to the Ge core enables a strong tuning of the optical and electrical properties of the material. An Al shell induces a bandgap shift toward smaller energies, and, in addition, it prevents Ge oxidation. The addition of a thin Si3N4 shell induces huge changes in the material spectral response, i.e., in the number of extracted excitons produced by a single photon. It increases both the absolute value and the width of the spectral response. For the best sample, we achieved an enhancement of over 250% of the produced number of excitons in the measured energy range. The observed changes are, as it seems, the consequence of the large tensile strain in Ge QDs which is induced by the Si3N4 shell addition and which is measured to be about 3% for the most strained QDs. The tensile strain causes activation of the direct bandgap of germanium, which has a very strong effect on the spectral response of the material.

To investigate the behavior of piles and the performance of the mechanically stabilized earth (MSE) walls under static and cyclic lateral loading, six reduced-scale model tests of single and group piles within the MSE walls were conducted inside a test box. In the single pile tests, a hollow aluminum tube as a pile was placed at a distance of 2D or 4D (D is pile diameter) behind the wall facing, while in the group pile tests, the piles were only placed at the distance of 2D with a spacing of 3.3D between the piles. The piles were subjected to static lateral loading only and cyclic lateral loading followed by static loading until failure. The test results showed that the lateral load capacity of each pile in the group pile test was approximately 60% that of the single pile, while the wall facing displacements and the geogrid strains in the group pile test were larger than those in the single pile test. The lateral pile capacity, the wall facing displacement, the strain in the geogrid, and the lateral earth pressure behind the wall facing in the static and cyclic loading tests were evaluated at the pile head displacement equal to 20%D. [ABSTRACT FROM AUTHOR]

The rheological properties of polymer have profound effects on the displacement efficiency of polymer in reservoir porous medium. This paper investigated the effects of polymer concentration, temperature, metal ions, and mechanical shear on the elongational rheological behavior of ultra-high molecular weight HPAM (U-HPAM) and normal medium molecular weight HPAM (M-HP AM). It was found that the intermolecular entanglement and elongational viscosity increased with HP AM concentration, and U-HP AM exhibited superior ability to enhance the elongational viscosity than M-HP AM. The intermolecular entanglement was reduced by increasing temperature, increasing Na+, Ca2+, Mg2+, Fe3+, Fe2+ concentrations and enhancing mechanical shear, which correspondingly decreased the elongational viscosity. Temperature and additional Na+, Ca2+, Mg2+, Fe3+ had severe impact on the elongational behavior of M-HPAM more than that of U-HPAM, while the additional Fe2+ and mechanical shear had the similar effects on the elongational behavior of M-HPAM and U-HPAM. Seepage and core displacement experiments exhibited that U-HPAM had better profile control ability than M- HP AM, and it could play a better role in oil displacement in strong heterogeneous formation. [ABSTRACT FROM AUTHOR]

Monolayer MoS2 is a typical transition metal dichalcogenides (TMDs), which is similar to graphene. However, MoS2 is a direct band gap semiconductor material. Based on the density functional theory, the changes of band structure, densities of states, phonon dispersion relations, and Raman spectrum of 2H monolayer MoS2 under ab biaxial strain are studied in this paper. The results show that the band gap, the structural stability, and the peak value of Raman spectrum of monolayer MoS2 are obviously changed under the biaxial strain. At compressive strain of 4%, monolayer MoS2 changed from direct band gap semiconductor to indirect band gap semiconductor, and at tensile strain of 10%, it changed from semiconductor material to metal material. During compressive strain above 4%, imaginary frequency appears in the phonon dispersion curve, and it means that the structure becomes unstable. [ABSTRACT FROM AUTHOR]

This study has aimed to analyze the effect of alkali treatment and drying method on the surface morphology and tensile properties of single coir fibers. The treatments of the coir fibers have been configured on the concentration of alkali solution, the soaking period, and the drying method. Furthermore, they have been soaked in 2 wt% and 6 wt% sodium hydroxide solution at room temperature for 1- and 2-hours soaking periods. The drying procedures adopted have been air, oven, and sun-drying. Observations with a scanning electron microscope (SEM) show that the coir surface is coarser, especially on fibers treated with 6 wt% sodium hydroxide solution. The properties such as tensile strength and strain, as well as tensile modulus of the different samples have been measured. The results have showed that the treated coir fiber with the 2 wt% concentration alkali solution has lower tensile strength than the untreated one. The treated coir with 6 wt% sodium hydroxides has the most considerable tensile strength. The effect of the soaking period on the tensile properties has been influenced by the drying method. Therefore, the appropriate combination of the soaking period and the drying method increase single coir fibers tensile properties. Slow drying (air-drying) has generated better tensile properties than the fast method (oven and sun-drying). [ABSTRACT FROM AUTHOR]

The results of studying the resistivity, magnetoresistance, and Hall coefficient of thin films of bismuth and the bismuth–antimony system on a borosilicate-glass substrate under plane tensile strain are presented. Deformation is created by a specially developed method that allows a change in its magnitude directly during measurement of the film properties. The films are obtained by thermal evaporation in vacuum. Varying the technological modes made it possible to obtain films of various structures: from small blocks to single crystal. Based on the experimental results, within the framework of the two-band approximation, the concentrations of charge carriers and the positions of the energy extrema of the valence and conduction bands relative to the chemical potential level are calculated. It is shown that the two-band approximation is insufficient for describing the properties of films of the studied compositions under plane tensile strain. [ABSTRACT FROM AUTHOR]

The excellent cracking control characteristics and high ductility of engineered cementitious composites (ECC) make it a promising research prospect as a waterproof material. In order to design an ECC with excellent waterproof performance and good mechanical properties, nonionic paraffin emulsion (NPE) was used to modify ECC. The influence of NPE on the mechanical performance and water-repellent characteristics of ECC was explored experimentally. The results show that NPE significantly improves the hydrophobic performance without significantly reducing the mechanical properties of ECC. The capillary water absorption coefficient of ECC decreases, and the permeability resistance increases obviously with the increasing of NPE content. Meanwhile, the tensile strain capacity is always greater than 6 %. When the NPE content is higher than 1 %, the water contact angle of ECC is larger than 90°, indicating that the material exhibits good hydrophobicity. This study shows that NPE is an excellent admixture to improve the impermeability of ECC. • NPE significantly improves the hydrophobic performance of ECC. • Permeability resistance of ECC increases with the rising of NPE content. • Tensile strain capacity of waterproof ECC is always greater than 6 %. [ABSTRACT FROM AUTHOR]

• Prediction of three two-dimensional binary compound of silicon nitride. • Electronic structures of the three stable structures are investigated. • The electronic structures can be tuned by strain engineering. The two-dimensional (2D) IV-V semiconductors have attracted much attention due to their fascinating electronic and optical properties. In this work, we predicted three phases of silicon nitrides, denoted α-Si 2 N 2 , β-Si 2 N 2 , and γ-Si 4 N 4 , respectively. Both α-Si 2 N 2 and β-Si 2 N 2 consist of two buckled SiN sheets, and γ-Si 4 N 4 consists of two puckered SiN sheets. It is challenging to transform between α-Si 2 N 2 and β-Si 2 N 2 because of the high energy barrier. The three dynamically stable bilayers are semiconductors with fundamental indirect band gaps from 0.25 eV to 2.92 eV. As expected, only the s and p orbitals contribute to the electronic states, and the p z orbitals dominate near the Fermi level. Furthermore, insulator-metal transitions occur in α-Si 2 N 2 and β-Si 2 N 2 under the biaxial strain of 16 %. These materials perhaps have potential applications in microelectronics and spintronics. [Display omitted] [ABSTRACT FROM AUTHOR]

• Chemical adsorption has higher energy than that of physical adsorption in P/Gra unexpectedly. • Underlying mechanism can be attributed to the distortion caused by p chemisorption. • Tensile strain can counterbalance the distortion energy. • The induced magnetic moment seems stronger in proposed P/Gra than that in B/Gra. Recent studies have identified that boron adatom chemisorbs on graphene with a weak localized magnetic moment. Using hybrid exchange-correlation functional, we show that P adatom rather than As can also chemically adsorb on the bridge site (Bri) of graphene. However, due to the large local distortion caused by P adsorption, the most energetically favorable site is Hollow (H) site instead with physisorption. Tensile strain (ε) is able to counterbalance the dominant distortion and can switch the stable site from H to Bri when ε exceeds 2.3 %. The corresponding localized magnetic moment is sizable with 1.00 µ B , which seems stronger than the case of B adatom. Such apparent spin-polarization stems from the abundant charge transfer from P adatom to graphene. We also find that interlayer coupling of graphene can reduce the threshold of tensile strain significantly. Our findings might extend the atomic scale magnetism on graphene from hydrogen/boron to underlying phosphorus. [Display omitted] [ABSTRACT FROM AUTHOR]

van der Waals heterostructures (vdWHs) have attracted significant interest as unique structures for application in nanoelectronic devices. A novel BC 6 N/ZnO vdWH was prepared by superimposing BC 6 N semiconductor wafers onto a hexagonal ZnO monolayer. The electronic structure, optical absorptivity, and power conversion efficiency (PCE) of BC 6 N/ZnO vdWH under tensile strain were studied using first-principles calculations. The band structure of the BC 6 N/ZnO vdWH exhibited a type-I band alignment with a direct bandgap of 1.92 eV. The type-I direct bandgap transformed into a type-II indirect bandgap when the uniaxial and biaxial tensile strains were increased to 10 %. Although the bandgap of the BC 6 N/ZnO vdWH increased (from 1.92 to 2.20 eV) monotonically with uniaxial strain (0–10 %), it was nearly independent of biaxial strain. The BC 6 N/ZnO vdWH exhibited a wide range and strong optical absorption in the ultraviolet (UV)–visible range; the absorptivity curve was red-shifted, and the optical absorptivity significantly increased in the UV region with increasing tensile strain. The PCE of BC 6 N/ZnO vdWH reached 22.5 % and 15.3 % under 10 % biaxial and uniaxial strains, respectively. The tunable electronic structure, excellent optical absorptivity, and ultrahigh PCE of BC 6 N/ZnO vdWH can be used in designing two-dimensional high-efficiency photovoltaic devices. [Display omitted] • A novel type-I BC 6 N/ZnO van der Waals heterostructure with a direct bandgap of 1.92 eV was investigated. • The BC 6 N/ZnO heterostructure exhibits type-II indirect bandgap under 10 % tensile strain. • The BC 6 N/ZnO shows improved optical absorptivity and a red-shifted absorption curve under tensile strain. • BC 6 N/ZnO exhibits an ultrahigh PCE (22.5 % and 15.3 %) under 10 % tensile (biaxial and uniaxial) strain. • The electronic and optical properties of BC 6 N/ZnO can be modulated by tensile strain. [ABSTRACT FROM AUTHOR]

Ethanol oxidation reaction (EOR) at the anode of direct ethanol fuel cells (DEFCs) obeys C1/C2 dual-pathway reaction mechanism, and improving the selectivity of C1 pathway is crucial to the commercialization of DEFCs. Herein, a novel hydrogen-implanted PdGa single-atom alloy metallene (H-Ga 1 Pdene) is designed for optimizing the C1 pathway to achieve greatly enhanced C1 pathway selectivity through electronic and strain engineering. Benefiting from the strong p-d orbital hybridization interaction and tensile strain effect induced by hydrogen-implantation, H-Ga 1 Pdene exhibits high mass activity of 10.34 A mg Pd −1 and C1 pathway selectivity of 54.7%, both showing an order of magnitude higher than that of commercial Pd/C. Theoretical calculations reveal that the p-d hybridization interaction could effectively accelerate the C-C bond cleavage and tensile strain enable efficient oxidation of CO* and CH 3 * produced by the C-C bond cleavage in C1 pathway, enabling H-Ga 1 Pdene to efficiently catalyze the complete electrooxidation of ethanol through the C1 pathway. [Display omitted] • Hydrogen-implanted PdGa single-atom alloy metallene (H-Ga1Pdene) was fabricated. • Both p-d orbital hybridization and tensile strain were induced by interstitial hydrogen. • p-d hybridization and tensile strain facilitated EOR activity and C1 pathway selectivity. • The C1 pathway selectivity of H-Ga1Pdene for EOR was 54.7%. • Uncover the underlying mechanism of p-d hybridization and tensile strain for efficient EOR. [ABSTRACT FROM AUTHOR]

Polyvinyl chloride (PVC) is used to obtain a wide range of materials for various purposes. High demand of PVC is explained by possibility to modify polyvinyl chloride and produce broad range of materials with improved properties as well as to have cost efficient ratio: productivity, available raw materials, saving of natural resources. However, under normal temperature polyvinyl chloride is brittle and inelastic, that limits the fields of PVC application. The production of basic PVC compositions is impossible without plasticizers – low-molecular compounds that allow direct regulating physical and mechanical properties of polymer. Production of plasticizers became one of the most important branch of petrochemical industry. Recently, however, the range and production of plasticizers have drastically decreased due to the increased cost, which reduced the competitiveness of plasticized PVC products. Therefore, the expansion of plasticizer variety for PVC is a strategic task of great practical significance. The present work describes synthesis methods of esters on the basis of oxyalkylated alcohols suggested as polyvinyl chloride plasticizers. Physico-chemical properties of synthesized compounds were studied. Conditions for their production with maximum outcome were selected. The results of experiments in which obtained compounds were tested as additives in the plasticization of PVC showed that the obtained samples of cable plastic, adhesive PVC tapes and multi-layered polyvinyl chloride linoleum satisfy all the technical requirements by the main indicators: cable plastic compound – GOST 5960-72 with amendment 1-9; a PVC adhesive tape – Technical Conditions – 2245-001-00203312-2003; multilayered linoleum – GOST 7251-77. According to the experimental results, phthalates of oxyalkylated alcohols possess rather high efficiency as plasticizers of polyvinyl chloride and are recommended for use in the above-mentioned industrial PVC recipes

In the areas of catalysis and renewable energy conversion, the development of active and stable electrocatalysts continues to be a highly desirable and crucial aim. Single-atom catalysts (SACs) provide isolated active sites, high selectivity, and ease of separation from reaction systems, becoming a rapidly evolving research field. Unfortunately, the real roles and key factors of the supports that govern the catalytic properties of SACs remain uncertain. Herein, by means of the density functional theory calculations, in the Au/WSSe SAC, built by filling the single Au atom at the S vacancy site in WSSe monolayer, we find that the powerful binding between the single Au atom and the support is induced by the Au d and W d orbital hybridization, which is caused by the electron transfer between them. The extra tensile strain could further stabilize the Au/WSSe by raising the transfer electron and enhancing the orbital hybridization. Moreover, by dint of regulating the antibonding strength between the single Au atom and H atom, the extra tensile strain is capable of changing the electric-catalytic hydrogen evolution reaction (HER) performance of Au/WSSe as well. Remarkably, under the 1% tensile strain, the reaction barrier (0.06 eV) is only one third of that of free state. This theoretical work not only reveals the bonding between atomic sites and supports, but also opens an avenue to improve the electric-catalytic performance of SACs by adjusting the bonding with outer factors.

We demonstrate high-sensitivity fiber strain sensors based on an elongated abrupt taper. The fiber abrupt taper, with a tapered diameter ranging from 40–60 μm, was made by using a hydrogen microflame to break the waveguide adiabaticity so as to convert the fundamental mode into cladding modes. The abrupt taper was further uniformly tapered by using a normal moving flame with a torch diameter of 7 mm to elongate the tapered region until the tapered diameter was down to 2.5–5 μm. The excited high-order modes were confined to propagate along the cladding and then recombined at the rear edge of the fiber taper to produce interferences with extinction ratios of up to 16 dB. The tapered region was pulled outwardly to change the optical path difference (OPD) between modes to measure the tensile strain with all the interfering wavelengths blue-shifted. The measured best strain sensitivity was 116.21 pm/με and the coefficient of determination R2 of linear fitting exhibits high linearity. This strain sensor based on elongated abrupt taper is several times higher than that of most of the fiber strain sensors ever reported.

With the increasing research on heterojunctions, it is gradually been realized that interface structure and strain have a huge impact on film properties. However, the research on Bi-based superconducting heterojunctions is still lacking and needs to be explored at the atomic-scale. In this article, the interface structure, element diffusion, and lattice mismatch relaxation of the Bi 2 Sr 2 CaCu 2 O 8+δ (Bi-2212)/SrTiO 3 heterojunction have been investigated by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (Cs-HAADF STEM), energy-dispersive X-ray spectroscopy (EDX), and geometric phase analysis (GPA). The experiment results reveal the interfacial atomic sequence as SrTiO 3 (TiO 2 -terminated)-SrO-Cu/TiO 2 –Ca–BiO-(Bi-2212) n , where the SrO layer is the nucleation layer and Ti atoms diffuse into the CuO 2 layer. The Bi-2212/SrTiO 3 heterointerface is found to be semi-coherent and accompanied by the non-ideally periodic arrangement of stand-off misfit dislocations. Moreover, lattice distortion and stacking fault have also been revealed to release part of the in-plane lattice mismatch. Through the combined effect of the above several lattice mismatch relaxation methods, the final Bi-2212 film experiences an average in-plane tensile strain (ε xx ~ +0.414%) compared with bulk Bi-2212. [ABSTRACT FROM AUTHOR]

The dynamic inverter using amorphous indium-gallium-zinc oxide thin-film transistors (a-IGZO TFTs) is revealed to be more robust to tensile strain than the static inverter that is most widely used in TFT circuits. The results with the inverters can be reasonably extended to NAND or NOR gates, because all of them are commonly composed of pull-up and pull-down networks. The experimental results after tensile bending up to 20 000 times with a bending radius of 1.5 mm show that $\Delta \text{V}_{{\text {OH}}}$ and $\Delta \text{V}_{{\text {OL}}}$ in the dynamic inverter decrease to 85% and 0% of those in the static inverter, respectively. Also, while the power consumption of the static inverter increases by 36%, which is tens of $\mu \text{A}$ , the dynamic inverter maintains low-power consumption, which is tens of nA. It is also worth noting that ratioed design and TFT operation in the saturation region make the circuit more sensitive to tensile strain than ratio-less design and TFT operation in the triode region. [ABSTRACT FROM AUTHOR]

An effective method, reducing the material volume of the air cavity by asymmetrical tapering fiber, is demonstrated to enhance the sensitivity of the strain sensor dramatically. High-sensitive strain sensors are fabricated through this method that splicing and tapering fiber with arc discharge at the misaligned center of the air cavity. The strain sensitivity of the sensor is measured to be ∼ 41.81 pm/μϵ at a resonant wavelength ∼ 1560 nm ranging from 0 to 500 μϵ. In addition, the experimental results show that the asymmetrical tapered-fiber enables both the material volume to smaller and the wall thickness to thinner, resulting in strain sensitivity higher. The proposed sensors have the advantages of fabricated repeatability, high sensitivity, and compact size, benefiting its practical sensing applications. [ABSTRACT FROM AUTHOR]

Graphene is widely used for nano-devices due to its distinctive band structure and fascinating properties. The substrates could significantly affect the properties of graphene and related devices. In this work, we investigate the effect of surface morphology and roughness of patterned silicon nitride substrates on Raman scattering and stress of graphene. We find that the Raman scattering of graphene depend strongly on surface morphology and roughness of patterned substrates. It is concluded that the peak red-shifts in 2D and G bands was due to the strain induced by patterns with different surface morphology (holes and trenches) and roughness. Furthermore, the effects of morphology of patterned area are much greater than the role of surface roughness in the induced strain of graphene. Due to the larger surface area (about 1.65 times), the strain in the grooves is greater than in holes, in spite of greater surface roughness in holes. Our results also reveal that the effect of pattern depth should be taken into account to understand the Raman peak shift and the strain change of graphene. Our work is fundamentally important for understanding the graphene properties on dependence of surface morphology of substrates and enhancing the interfacial strength of graphene-based devices.

Nitrate is one of the essential raw ingredients in agriculture and industry. The electrochemical nitrogen oxidation reaction (NOR) is promising to replace the conventional nitrate synthesis industry with high energy consumption and greenhouse gas emission. Here, tensile‐strained palladium porous nanosheets (Pd‐s PNSs) were prepared. They exhibited enhanced activity for electrochemical NOR at ambient conditions, greatly outperforming Pd nanosheets. 15N isotope labeling experiments proved that nitrate originated from nitrogen oxidation. Combining electrochemical in situ Raman and FTIR spectroscopy with density functional calculations, it was revealed that the tensile strain could facilitate the formation of NOR active species of PdO2, leading to high activity. [ABSTRACT FROM AUTHOR]

This study focuses on the absorption characteristics and evolution of key properties of silicone rubber (SiR) in the presence of silicone grease; a typical material used in power cable accessories. Diffusion mechanism of silicone grease within the SiR is investigated and the results indicate that it follows Langmuir diffusion model in the absence of significant swelling. Silicone grease absorption behavior is also explored under tensile strain and at various temperatures. The tensile strain accelerates and increases the absorption of silicone grease. In addition, the influence of the absorbed silicone grease on the key electrical and mechanical properties of SiR is surveyed. The investigation shows that the properties deteriorate. In addition, the mechanism of the mechanical property deterioration of SiR is discussed. [ABSTRACT FROM AUTHOR]

The power conversion efficiencies (PCEs) of the solar cells containing metal halide perovskites (MHPs) have rapidly increased and exceeded 25% during the past decade. The photovoltaic properties of these devices are extensively investigated in terms of their microstructures, environmental characteristics, and carrier dynamics, and the MHP structural evolution under high pressure is evaluated. In addition, the energy level structure, electron/hole dynamics, and optical/electronic properties of MHPs with anisotropic crystal structures are examined. However, the correlation between the structural anisotropy and material properties of these perovskites is rarely considered in the literature studies on their high‐pressure behavior. In this progress report, the optical/electronic properties of MHPs with anisotropic structures under thermal, mechanically imposed, and in‐service strains/stresses that have been previously neglected by researchers are summarized. [ABSTRACT FROM AUTHOR]

Highly tensile-strained Ge quantum dots (TS-Ge-QDs) emitting structures with different size were successfully grown on InP substrates by molecular beam epitaxy. Dislocation-free TS-Ge-QDs were observed by transmission electron microscopy. Finite element modeling indicates a maximum tensile strain of 4.5% in the Ge QDs, which is much larger than the required strain to achieve direct band gap conversion of Ge based on theoretical prediction. Photoluminescence (PL) from a direct band-gap-like transition of TS-Ge-QDs with a peak energy of 0.796 eV was achieved and confirmed by the etch depth-dependent PL, temperature-dependent PL, and excitation-power-dependent PL. In addition, a strong defect-related peak of 1 eV was observed at room temperature. The band structure of the TS-Ge-QDs emitting structures was calculated to support the experimental results of PL spectra. Achieving PL from direct band-gap-like transitions of TS-Ge-QDs provides encouraging evidence of this promising highly tensile strained semiconductor-nanostructure-based platform for future photonics applications such as integrated light sources. [ABSTRACT FROM AUTHOR]

Flexible strain sensors have aroused widespread concern due to their potential applications in detecting human motion and health. Carbon-based materials are surpassing candidate materials for flexible strain sensors with superior performances, because of their outstanding electrical conductivity, lightweight and flexibility, and excellent stability. In order to satisfy the detecting requirements for different strain forms in practical applications, various types of strain sensors based on carbon materials have been designed and prepared, including tensile, pressure, bending, torsion, and multiplex strain sensors. Herein, the latest advances in the preparation of flexible carbon-based strain sensors are reviewed according to the strain types. Furthermore, the potential applications and existing challenges of sensors in the field of human motion and physiological information detection are summarized. This review aims to provide some references for further exploitation of high-performance flexible carbon-based strain sensors. [ABSTRACT FROM AUTHOR]

A record high electron mobility of 698 cm2/ $\text{V}\cdot \text{s}$ in a tensile-strained Ge0.96Sn0.04 nMOSFET is demonstrated in this letter. High-quality GeSn films were epitaxially grown by low-temperature chemical vapor deposition. Different strain conditions in the active GeSn layers were achieved by Ge or GeSn relaxed buffers. A mesa FET structure was used to effectively reduce the OFF leakage by a recessed p/n junction in Ge. The ION/IOFF ratio in the mesa GeSn FETs is boosted by a factor of 100 compared to conventional planar devices. As the GeSn film becomes more tensile strained, the channel mobility is enhanced, which could be attributed to a higher carrier population in the ${\Gamma }$ valley. [ABSTRACT FROM AUTHOR]