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Proton-conducting BaZrO3-doped electrolytes are considered as potential high temperature proton conductors due to their high ionic conductivity and electrical efficiency in the operating temperature range of solid oxide fuel cells. However, doping leads to a decrease in grain boundary conductivity and greatly limits its applications. Here, the charge transport properties of sub-micro and nano-BaZrO3 electrolytes were studied by in situ high-pressure impedance measurements and first-principles calculations. Mixed ionic-electronic conduction was found in both samples in the whole pressure range. Pressure-induced negative capacitance in the tetragonal phase of nano-BaZrO3 was observed, which was related to the space charge layer of grain boundaries as well as the electrostrictive strain of grains. The enhanced electrostrictive effect was attributed to the existence of polar nano-domains in nano-BaZrO3. Furthermore, the coincident imaginary part of impedance and modulus peaks on the frequency scale indicated a non-localized carrier conduction in the tetragonal phase of nano-BaZrO3. The grain boundary conductivity of nano-BaZrO3 was enhanced by four orders of magnitude, and the impedance response changed from a constant phase element to an ideal capacitance, which was accompanied by the cubic to tetragonal phase transition. At a switching frequency of 0.1 Hz, the real part of the dielectric function of nano-BaZrO3 increases sharply with frequencies from negative to positive values, exhibiting a plasma-like Drude behavior. Our results provide insight into the optimization and application of BaZrO3-based proton conductors in solid oxide fuel cells. [ABSTRACT FROM AUTHOR]

The n-type Ce:ZnO (NL) grown using a hydrothermal method was deposited on a p-type boron-doped nanoleaf diamond (BDD) film to fabricate an n-Ce:ZnO NL/p-BDD heterojunction. It shows a significant enhancement in photoluminescence (PL) intensity and a more pronounced blue shift of the UV emission peak (from 385 nm to 365 nm) compared with the undoped heterojunction (n-ZnO/p-BDD). The prepared heterojunction devices demonstrate good thermal stability and excellent rectification characteristics at different temperatures. As the temperature increases, the turn-on voltage and ideal factor (n) of the device gradually decrease. The electronic transport behaviors depending on temperature of the heterojunction at different bias voltages are discussed using an equilibrium band diagram and semiconductor theoretical model. [ABSTRACT FROM AUTHOR]

Because additively manufactured materials are increasingly being used in load-bearing structures, strength research has become critical. Surprisingly, numerous studies have reported the tensile strength measurements, but only a few studies have presented meaningful results for the shear strength measurements of additively manufactured polymers. Hence, this paper proposes a combined experimental and numerical investigation of a new interlayer shear strength measurement approach, and it targeted the applications of the same polyamide (PA12) specimens made with fused deposition modeling (FDM) and selective laser sintering (SLS). A necking-shaped shear specimen was developed to measure the pure shear strengths with the aid of a three-dimensional (3D) finite element analysis. The results showed that the specimens made with FDM and SLS exhibited totally different shear failure behaviors. The ultimate shear strength of the FDM-PA specimens had more than a 32% increase over that of the SLS-PA specimens. An interface mechanics assumption was employed to explore the different shear failure mechanisms with the support of a fractography analysis. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the present study was to explore the feasibility of transdermal delivery of metformin, a commonly used oral antidiabetic drug, by ionic liquid (IL) technology. Methods: Metformin hydrochloride (MetHCl) was first transformed into three kinds of ILs with different counterions. The physicochemical properties of the obtained ILs were characterized in depth. The simulation of stable configuration and calculation of interaction energies were conducted based on density functional theory (DFT). Skin-PAMPA was used to evaluate the intrinsic transdermal permeation properties. The cytotoxicity assay of these ILs was conducted using HaCaT cells to evaluate the toxicity to skin. These metformin ILs were then formulated into transdermal patch, and the transdermal potential was further evaluated using in vitro dissolution test and skin permeation assay. Finally, the pharmacokinetic profiles of these metformin IL-containing patches were determined. Results: Among all the three Met ILs, metformin dihexyl sulfosuccinate (MetDH) with proper overall physiochemical and biological properties demonstrated the highest relative bioavailability. Metformin docusate (MetD) with the highest lipophilicity and intrinsic transdermal permeability exhibited the most significant sustained release profile in vivo. Both MetDH and MetD were the promising candidates for further clinical investigations. Conclusions: Overall, the properties of ILs were closely related to the structures of counterion. IL technology provided the opportunities to finely tune the solid-state and biological properties of Metformin and facilitated the successful delivery by transdermal route. [ABSTRACT FROM AUTHOR]

Automatic modulation classification (AMC) plays a fundamental role in common communication systems. Existing clustering models typically handle fewer modulation types with lower classification accuracies and more computational resources. This paper proposes a hierarchical self-organizing map (SOM) based on a feature space composed of high-order cumulants (HOC) and amplitude moment features. This SOM with two stacked layers can identify intrinsic differences among samples in the feature space without the need to set thresholds. This model can roughly cluster the multiple amplitude-shift keying (MASK), multiple phase-shift keying (MPSK), and multiple quadrature amplitude keying (MQAM) samples in the root layer and then finely distinguish the samples with different orders in the leaf layers. We creatively implement a discrete transformation method based on modified activation functions. This method causes MQAM samples to cluster in the leaf layer with more distinct boundaries between clusters and higher classification accuracies. The simulation results demonstrate the superior performance of the proposed hierarchical SOM on AMC problems when compared with other clustering models. Our proposed method can manage more categories of modulation signals and obtain higher classification accuracies while using fewer computational resources. [ABSTRACT FROM AUTHOR]

Let H = (V (H) , E (H)) be a hypergraph, where V (H) is a set of vertices and E (H) is a set of non-empty subsets of V (H) called edges. If all edges of H have the same cardinality r , then H is an r -uniform hypergraph. A hypergraph H ′ = (V (H ′) , E (H ′)) is called a hypersubgraph of a hypergraph H = (V (H) , E (H)) if V (H ′) ⊆ V (H) and E (H ′) ⊆ E (H). The v e r t e x - c o n n e c t i v i t y of hypergraph H , denoted by κ (H) , is the cardinality of a minimum vertex set S such that H − S is disconnected or is a trival hypergraph. We call H k - c o n n e c t e d if κ (H) ≥ k. Tian, Lai and Meng [Y. Z. Tian, H.-J. Lai, J. X. Meng, On the sizes of vertex- k -maximal r -uniform hypergraphs, Graphs and Combinatorics 35(5) (2019) 1001–1010] conjectered that, for sufficiently large n , every n -vertex r -uniform hypergraph with no (k + 1) -connected hypersubgraphs has at most n r − n − k r + n k − 2 k r edges. This upper bound is equal to 1 2 k (n − k) 2 + 2 3 k 2 (n − k) − 3 2 k − 2 9 (n − k) when r = 3. In this paper, we prove that for k ≥ 3 and n ≥ 2. 6 7 k , every n -vertex 3 -uniform hypergraph with no (k + 1) -connected hypersubgraphs has at most 3 5 k (n − k) 2 + 1 2 k 2 (n − k) − k (n − k) + 1 3 (n − k) edges. [ABSTRACT FROM AUTHOR]

The heavier alkaline-earth hydrides AeH2 (Ae = Ca, Sr, and Ba) are considered as promising materials for hydrogen energy storage. Pressure-induced structural changes in AeH2 materials could improve hydrogen transport properties and result in a better understanding of the structure-property relationship. In this work, pressure evolution of carrier transport properties of SrH2 was investigated using impedance spectroscopy measurements at room temperature and first-principles calculations. The pressure-induced structure phase transition from a Pnma phase to a P63/mmc phase was accompanied by a transition from pure electronic conduction to mixed ionic-electronic conduction, which was related to the ionic migration barrier energy. In the P63/mmc phase, the H− ionic and electronic resistances of bulk and grain boundaries were distinguished, respectively. The total resistance of SrH2 decreased by about four orders of magnitude after the phase transition. This work provides critical insight into the structure-conduction relationship and the role of grain boundaries in the transport process of alkaline-earth hydrides under high pressure. [ABSTRACT FROM AUTHOR]

[Display omitted] • Structural dependent Fenton activity catalyzed by natural magnetite is studied. • Main influence factor of magnetite Fenton activity is probed by redundancy analysis. • Naphthol degradation is closely associated with Ti and V content. • H 2 O 2 accelerate e−−h+ separation of ilmenite resulting in high O 2 − generation. • Naphthol degradation is a detoxification process as revealed by GC–MS and ECOSAR. Magnetite is a ubiquitous iron mineral in nature and its iron ions are usually isomorphically substituted by Ti and V cations, which shows a high ability for degradation of organic contaminants via the photo-Fenton process. However, numerous reports pay more attention to the activity of synthetic magnetite rather than natural magnetite. Here, three types of natural magnetite (HG01, HG02, and GCL01) with different Ti and V contents were investigated from the perspective of the difference in structural property, catalytic activity, H 2 O 2 decomposition, and reactive oxygen species generation. Structural characterization exhibited that the purity of natural magnetite obeyed the order: GCL01 > HG02 > HG01. HG01 contained the highest Ti content in the form of ilmenite, followed by HG02 and GCL01. Moreover, HG01 yielded the highest photo-Fenton catalytic activity with 99.5 % of naphthol degradation and 96.0 % of H 2 O 2 decomposition after 60 min reaction. The superior activity of HG01 was attributed to the relatively high Ti and V content as demonstrated by redundancy analysis. Mechanistic investigation implied that the Ti and V in the octahedral sites of the magnetite surface can accelerate the electron transfer from Fe(III) to Fe(II), resulting in higher Fenton activity. Besides, ilmenite in HG01 enhanced naphthol degradation because H 2 O 2 accelerated the separation of photoelectron-holes pairs to promote O 2 − production. Furthermore, as revealed by gas chromatography-mass spectrometry and the toxicity of identified products predicted by the ECOSAR model, the toxicity of naphthol can effectively reduce accompanied by the harmless products generated. The high reusability, low iron ions residual in water, harmless end products, and easily recycled with magnetic separation suggest that natural magnetite has a promising application prospect for wastewater purification. [ABSTRACT FROM AUTHOR]

The purpose of this study was to explore the feasibility and mechanism of synthesizing silver nanoclusters (AgNCs) using a double-stranded DNA (dsDNA) template and to use the AgNCs as probes for captopril detection. The results showed that the binding of silver ions towards DNA bases deduced the destruction of the initial dsDNA structure, and AgNCs with decent quantum yield (43.54%) were obtained. The detection using these AgNCs probes showed good performance for captopril, with a linear range of 0.1–0.8 μg·mL−1 and a detection limit of 0.045 μg·mL−1. Recovery results in real samples of Apocynum venetum leaf tea and Ginkgo biloba leaf tablet demonstrated its good applicability. This work not only extended the understanding of DNA-AgNCs but also provided a fast and cost-effective tool for captopril detection. • The template dsDNA underwent a structural transformation during the synthesis. • The synthesized AgNCs had a decent quantum yield of 43.56%. • This method was time-saving and cost-effective with good analytical performance. [ABSTRACT FROM AUTHOR]

Automatic modulation classification (AMC) has recently attracted widespread attention nowadays due to its desirable features of generalisability and requirement of little prior knowledge through artificial intelligence (AI) technology. The authors propose a stacked auto‐encoder (SAE) based on various optimisation methods structure to intelligently process a feature space that includes spectral‐based features and high‐order cumulants. To unify the dimensionality of the features, they apply different normalisation methods to the feature space before training the SAE model to decide corresponding normalisations under different noise environments. Linear normalisation is superior when signal‐to‐noise ratio (SNR) is low, and standardisation is superior when SNR is between ‐1 and 4 dB. Regularisation works best when SNR is greater than 5 dB. To increase the recognition accuracy of the proposed model, they introduce the unconstrained optimisation theory to adjust the proposed SAE model, including Nelder‐Mead method, Newton optimisation method, conjugate gradient method and quasi‐Newton method. They observe that the quasi‐Newton method offers desirable performance when optimising SAE model. It is the first time to compare these data normalisation methods and discuss unconstrained optimisation theory together to recognise modulation types. The recognition accuracy of this model for eight modulation types can reach 99.8% when SNR ranges from −5 to 10 dB. [ABSTRACT FROM AUTHOR]

In this paper, an improved long short-term memory (LSTM)-based deep neural network structure is proposed for learning variable-length Chinese sentence semantic similarities. Siamese LSTM, a sequence-insensitive deep neural network model, has a limited ability to capture the semantics of natural language because it has difficulty explaining semantic differences based on the differences in syntactic structures or word order in a sentence. Therefore, the proposed model integrates the syntactic component features of the words in the sentence into a word vector representation layer to express the syntactic structure information of the sentence and the interdependence between words. Moreover, a relative position embedding layer is introduced into the model, and the relative position of the words in the sentence is mapped to a high-dimensional space to capture the local position information of the words. With this model, a parallel structure is used to map two sentences into the same high-dimensional space to obtain a fixed-length sentence vector representation. After aggregation, the sentence similarity is computed in the output layer. Experiments with Chinese sentences show that the model can achieve good results in the calculation of the semantic similarity. [ABSTRACT FROM AUTHOR]

In this study, an optimal adaptive control approach is established to solve the robust output tracking problem of a class of continuous time uncertain linear systems based on the policy iteration (PI) in actor-critic algorithm. First, by augmenting the integral variables of the tracking error into state variables, the robust tracking problem is transformed into a robust control problem of an augmented uncertain linear system. It is proven that the robust control law of the augmented system enables the output of the considered system to track a polynomial time signal asymptotically. Second, an optimal control method in the corresponding auxiliary nominal system is established, and based on the Bellman optimality principle, PI algorithms are proposed to solve online tracking controllers for the matched and the mismatched uncertain systems. Finally, for testing the availability of the proposed approach and theoretical results, two numerical experiments are provided. [ABSTRACT FROM AUTHOR]

There is evidence from numerous studies that dysbiosis of the microbiome provokes various immune-mediated diseases, obesity, diabetes, and cancers by regulating metabolites, host genetics, environmental elements, and stress. Such reports are yet to define an accurate regulatory network for host-gut microbiome communication. miRNAs have recently emerged as crucial mediators of this communication, as portrayed by their interaction with the host microbiome. This mini-review summarizes the bi-direction effects between miRNA and microbiome and elucidates their role in carcinogenesis. An in-depth understanding of the association of miRNA with host-microbiome could be valuable to improve cancer remission, diagnosis, and treatment, and may help to potential tumor markers. [ABSTRACT FROM AUTHOR]

This work aimed to explore whether radiomic features on magnetic resonance diffusion weighted image (MR DWI) can be used to identify triple-negative breast cancer (TNBC) and other subtypes (non-TNBC). This retrospective study included 221 unilateral patients who underwent breast MR imaging prior to neoadjuvant chemotherapy. The subtypes of breast cancer include luminal A (n = 63), luminal B (n = 103), human epidermal growth factor receptor-2 (HER2) overexpressing (n = 30), and triple negative (n = 25). Radiomic features were extracted using Omini-Kinetic software on DWI. Student's t -test and Mann–Whitney U test were used to compare the features between TNBC and non-TNBC patients. Logistic regression analysis and receiver operating characteristic (ROC) curve were used to evaluate the diagnostic efficiency of radiomic features. The Fisher discriminant model was employed to distinguish TNBC and non-TNBC patients automatically. An additional validation dataset with 169 patients was utilized to validate the model. A total of 76 imaging features were extracted from each lesion on DWI images, and 12 radiomic features were statistically significant between TNBC and non-TNBC patients (P < 0.05). The area of receiver operating characteristic curve (AUC) was 0.817 to apply logistic regression analysis. The accuracy of Fisher discriminant model in distinguishing TNBC and non-TNBC patients was 95.4%, and leave-one-out cross validation was achieved with an accuracy of 83.7%. The same classification analysis of the validation dataset showed an accuracy of 83.4% and an AUC of 0.804. Breast lesions exhibit differences in radiomic features from DWI, enabling good discrimination between TNBC and non-TNBC tumors. • Distinguishing triple-negative breast cancer has crucial therapeutic implications. • Radiomic analysis may help identify subtypes by quantifying tumor heterogeneity. • Radiomic analysis extracts a large number of imaging features to identify subtypes. • Radiomic features exhibit differences between TNBC and non-TNBC tumors. [ABSTRACT FROM AUTHOR]

Automatic modulation classification (AMC) has recently attracted widespread attention nowadays due to its desirable features of generalisability and requirement of little prior knowledge through artificial intelligence (AI) technology. The authors propose a stacked auto‐encoder (SAE) based on various optimisation methods structure to intelligently process a feature space that includes spectral‐based features and high‐order cumulants. To unify the dimensionality of the features, they apply different normalisation methods to the feature space before training the SAE model to decide corresponding normalisations under different noise environments. Linear normalisation is superior when signal‐to‐noise ratio (SNR) is low, and standardisation is superior when SNR is between ‐1 and 4 dB. Regularisation works best when SNR is greater than 5 dB. To increase the recognition accuracy of the proposed model, they introduce the unconstrained optimisation theory to adjust the proposed SAE model, including Nelder‐Mead method, Newton optimisation method, conjugate gradient method and quasi‐Newton method. They observe that the quasi‐Newton method offers desirable performance when optimising SAE model. It is the first time to compare these data normalisation methods and discuss unconstrained optimisation theory together to recognise modulation types. The recognition accuracy of this model for eight modulation types can reach 99.8% when SNR ranges from −5 to 10 dB. [ABSTRACT FROM AUTHOR]

Structural parameters, electronic and optical properties of biphenylene have been investigated using the plane-wave ultrasoft pseudo-potential technique based on the first-principles density functional theory. The non-uniform pressure dependence of the lattice parameters may also mean that the biphenylene undergoes anisotropic compression. And the bulk modulus at ambient pressure and temperature is B0 = 12.37 GPa and its derivative is B ′ 0 = 7.09. Meanwhile, the pressure dependence of the electronic band structure, density of states and partial density of states of biphenylene were presented. It is shown that biphenylene is a semiconductor with a direct gap of 2.325 eV, and a pressure induced decrease of the band gap is observed. Moreover, the complex dielectric function, absorption coefficient, reflectivity, refractive index and extinction coefficient are calculated and analysed. According to our work, we found that the optical properties of biphenylene undergo a red shift with increasing pressure. [ABSTRACT FROM AUTHOR]

We have studied the transport properties of three different contact structures in Si2C2 clusters by using the first principles based on density functional theory (DFT) and non-equilibrium Green's function (NEGF) in this paper. Both M1 and M2 show excellent transport properties and a weak negative differential resistance (NDR) phenomenon appears due to greater transferring charge between the central area and the electrodes. The intermediate barrier of M3 is very large, and the electrons are difficult to transmit. However, it also shows good conductivity after we add sulfur (S) atoms at both ends of the molecule. Through the molecular projected self-consistent Hamiltonian (MPSH) analysis, the molecular orbital is expanded with the addition of S atoms, thus showing good conductivity. With the addition of the bias, the conductance of Si2C2 clusters at the Fermi level is reduced due to the drift of the energy level. It is interesting to note that there is a high resonant transmission peak at −1.14 eV under 2 V bias of the M3 system, which shows a molecular switching behavior. [ABSTRACT FROM AUTHOR]

It is very meaningful and useful to select specific aptamers with capacity to distinguish small structural analogues, but it is difficult to carry out by traditional affinity chromatography-SELEX (systematic evolution of ligands by exponential enrichment) based on immobilized target molecules. In this paper, as a proof of concept, we selected DNA aptamers that can specifically recognize and differentiate riboflavin and its derivative flavin adenine dinucleotide (FAD) by a modified method. Here, the random DNA library was indirectly immobilized on streptavidin functional agarose beads by hybridization with its biotinylated short complementary strand, and the specific affinity between aptamers and its target would induce the aptamers to release from beads. Binding specificity can be tailored by performing an additional negative SELEX with the structure analogue of target. After about 10 rounds of selection, 6 aptamers for riboflavin and 2 aptamers for FAD with good affinities were isolated, and their dissociation constants (K d s) were all at low micromolar level. Moreover, as expected, most of these aptamers show high affinity and excellent selectivity for target molecules, almost no binding to structure analogues and purines, indicating this simple method could be used to select specific aptamers to distinguish small molecular targets with similar structures. Image 1 • Specific DNA aptamers for different flavins (riboflavin and FAD) were successfully isolated. • Six aptamers for riboflavin with low micromolar dissociation constant (K d) were achieved after 14 rounds of selection. • Two aptamers for FAD with low micromolar K d were achieved after 12 rounds of selection. • Most of these aptamers showed high affinity and excellent selectivity for their target molecule over the structure analogue. • The effective SELEX strategy for selection specific aptamers against small molecules with similar structures was developed. [ABSTRACT FROM AUTHOR]

The stiffener plays an important role in the overall performance of T-stiffened skin assembly which is a primary structure of aircraft. In this paper, a thermo-viscoelastic finite element model that has been verified by experimental results was established to investigate the effect of the stiffener on stress concentration, stress redistribution, and deformation of T-stiffened skin assembly during curing. The size dependence of residual stress and deformation was analyzed by establishing a series of integrated assemblies with different sizes and stacking sequences of the stiffener. The sensitivity of residual stress and deformation to the stiffener size and stacking sequence was investigated. The results reveal that the overall residual stress of T-stiffened skin assembly is mainly sensitive to the fillet radius and the stacking sequence, whereas the residual stress of skin is almost not sensitive to the stiffener size. The maximum deformation of T-stiffened skin assembly is located in the skin, and the evolution of the maximum deformation is significantly affected by the flange length and stacking sequence. [ABSTRACT FROM AUTHOR]

The dielectric properties and the role of grain boundaries in polycrystalline tetracene were studied at pressures of up to 21.3 GPa using in situ impedance spectroscopy measurements. Two anomalous changes in some of the electrical parameters (resistance, relaxation frequency and relative permittivity) were found at 6.0 and 19.0 GPa, which were related to the structural rearrangement and condensation reaction processes, respectively. Within this pressure range, grain boundaries play an important role in polycrystalline tetracene's conduction mechanism. Based on first-principles calculations, it was found that the variation in bulk resistance under pressure was mainly caused by a change of band gap. Intermolecular interactions are more sensitive to pressure than intramolecular interactions. The decrease in the relative permittivity under pressure indicates the existence of space charge polarization of the interface layer in addition to electronic polarization. [ABSTRACT FROM AUTHOR]

Utilizing in situ Raman spectroscopy, resistivity, and Hall-effect measurements, we conducted an extensive investigation on the continuous electronic phase transitions and transport properties of two-dimensional (2D) tellurium (Te) under high pressure at room and low temperature (80–300 K). The distinguishable decrease in the A1 Raman mode's full width at half maximum in the trigonal phase (Te-I) indicated an electronic phase transition at 2.2 GPa. The following Hall-effect experiments located the Lifshitz transition and the semiconductor-semimetal transition at 0.9 and 1.9 GPa, respectively, and the semiconductor-semimetal transition was also confirmed by resistivity variation through temperature. The charge carrier types of the Te changed from hole to electron during the phase transition from Te-I to Te-II (triclinic phase) at low temperature, while the transport parameters remained almost unchanged during the phase transition from Te-II to Te-III (monoclinic phase). The results offered complete and thorough electronic phase transitions and transport characteristics of 2D Te, hence great advancing the potential application of Te in electronic devices. [ABSTRACT FROM AUTHOR]

• Cyclically tested three specimens of modular steel structures infilled with cold-formed steel walls (MSS-CFSWs). • Using the CFSW significantly improved the mechanical performance of the MSS. • Evaluated the use of a novel connection system between the CFSW and MSS. • The connections experienced little damage, indicating the module frame can be reused. • Derived and verified an equation for the shear capacity of the MSS-CFSW. A reusable connection system between a cold-formed steel wall (CFSW) and modular steel frame was developed to provide effective seismic resistance while ensuring repairability. Three steel frame specimens were cyclically loaded along the lateral direction to study the influence of the CFSW infill and its connection to the frame on seismic performance, thereby exploring the feasibility of the proposed connection configuration. The results indicated that modular steel structures infilled with cold-formed steel walls (MSS-CFSWs) using the proposed connection exhibited the "strong frame, strong connection, and weak infilled wall" failure mode. The use of a CFSW resulted in increments of 149.8%–307.5% and 53.4%–80.2% in the initial lateral stiffness and shear capacity, respectively. Connecting the CFSW to both the frame beams and columns resulted in superior mechanical performance and energy dissipation capacity. No separation between the CFSW and frame was observed, proving that the proposed connection configuration is safe and reliable. Furthermore, the connector plates and angles in the connection exhibited no evident deformation or damage, allowing the replacement of damaged CFSW components and the reuse of frames. The shear capacity of the MSS-CFSW was calculated by considering plastic hinge formation at the beam end as the critical state and using a modified global analysis method to determine the shear capacity of the CFSW. The resulting equation was verified using the test data and was found to be safely conservative. The results of this study can therefore serve as a reference for the design of MSS-CFSWs. [ABSTRACT FROM AUTHOR]

This paper synergistically addressed the microstructure alteration and the mechanical behavior of rubber during thermo-oxidative aging process from both experimental and numerical modeling aspects. Through the FTIR spectra analysis, equilibrium swelling experiment, low-field NMR measurement and mechanical tests of styrene-butadiene rubber (SBR) samples, a macromolecular network alteration mechanism was introduced. The mechanism is related to the variation of the crosslinking network and dangling chain ends of SBR during aging. A finite deformation based hyper-viscoelastic constitutive model was then established to capture the mechanical behavior of SBR during aging. Based on the interpretation of the microscopic mechanism, the above-mentioned network alterations during aging were considered in the model. After the implementation by means of the finite element simulation software ABAQUS, the accuracy of the established model was checked via the comparison of the numerical results with the corresponding data obtained from mechanical tests. The work is helpful for estimating rubber mechanical performance during aging process. Image 10405 • A macromolecular alteration mechanism relating to crosslink network and dangling chain ends during SBR aging was proposed. • A hyper-viscoelastic constitutive model relating to the observed microscopic mechanism of SBR aging was established. • Helmholtz free energy was decomposed into the equilibrium and the non-equilibrium part, respectively. • The numerical model was implemented through the finite element method and the accuracy of the model was verified. [ABSTRACT FROM AUTHOR]

Door and window openings, which universally exist in the external load bearing walls of module units, significantly impact the seismic performance and shear capacity of cold-formed steel walls (CFSWs). In this study, we conducted cyclic loading tests on three full-scale specimens to investigate the seismic performance of a single frame of modular steel structures infilled with cold-formed steel walls (MSS-CFSWs). The CFSW of two specimens had window and door openings, while that of the remaining specimen did not have any openings. Test results indicated that the failure mode of the specimens had two stages; the self-drilling screw connection of the CFSW failed first, followed by plastic hinges formation at the beam end of the steel frame. We observed 45° inclined cracks on the wallboards on both sides of the CFSW with openings. The window and door openings reduced the initial lateral stiffness by 24.4% and 28.7% and shear capacity by 3.8% and 15.5%, respectively, compared with those of the specimen without openings. Both the CFSW and steel frame contributed to the shear capacity of the MSS-CFSW. Furthermore, the irregular wallboard units were divided into rectangular wallboard units. Based on the modified global analysis method and the failure mode of the plastic hinges formed at the beam end, we developed a calculation method for the shear capacity of the specimen. We verified the accuracy of the proposed method by comparing the theoretical and test values. The results of this study are expected to serve as a reference for engineering design. • Cyclic loading tests conducted to investigate the seismic performance of the MSS-CFSW with openings. • Openings impact the seismic performance of the MSS-CFSW. • Lateral stiffness and shear capacity reduced by window and door openings. • Calculation method developed for the shear capacity of the MSS-CFSW proposed and demonstrated. [ABSTRACT FROM AUTHOR]

Simple Summary: The protein translation machinery, of which tRNA is an essential part, is critical in controlling the growth of tumor cells. The development of cancer is also influenced by translational dysregulation. Understanding the rewiring of gene expression at the translational level, which underpins the development of transformational phenotypes during cancer, has made tremendous strides in recent years. We have found that the mode of translation regulation centered on tRNAs affects the translation system in various cancer types in a variety of different ways. In addition to the expression level of tRNA itself, codon and amino acid usage bias, tRNA modification regulation, and tRNA-derived fragments all play important roles. This review discusses recent developments and new insights to elucidate the role of tRNA-centered translational regulatory models in some aspects of carcinogenic and cancer cell activity. Cancer is a leading cause of morbidity and mortality worldwide. While numerous factors have been identified as contributing to the development of malignancy, our understanding of the mechanisms involved remains limited. Early cancer detection and the development of effective treatments are therefore critical areas of research. One class of molecules that play a crucial role in the transmission of genetic information are transfer RNAs (tRNAs), which are the most abundant RNA molecules in the human transcriptome. Dysregulated synthesis of tRNAs directly results in translation disorders and diseases, including cancer. Moreover, various types of tRNA modifications and the enzymes responsible for these modifications have been implicated in tumor biology. Furthermore, alterations in tRNA modification can impact tRNA stability, and impaired stability can prompt the cleavage of tRNAs into smaller fragments known as tRNA fragments (tRFs). Initially believed to be random byproducts lacking any physiological function, tRFs have now been redefined as non-coding RNA molecules with distinct roles in regulating RNA stability, translation, target gene expression, and other biological processes. In this review, we present recent findings on translational regulatory models centered around tRNAs in tumors, providing a deeper understanding of tumorigenesis and suggesting new directions for cancer treatment. [ABSTRACT FROM AUTHOR]

We investigated the relationship between the object control and emotional understanding of children aged 3 to 6 years, and the underlying mechanisms of its action. Using cluster sampling, we assessed the object control, inhibitory control, and emotional understanding of 694 children attending two kindergartens in a prefecture-level city in China. The children completed the Test of Gross Motor Development-2, the day–night Stroop task, and emotional understanding tasks. The results showed that the children's object control skills positively and significantly predicted their emotional understanding and inhibitory control. Object control skills affected emotional understanding not only directly, but also through the mediating effect of inhibitory control. These findings can provide theoretical guidance and practical approaches for improving children's emotional understanding. [ABSTRACT FROM AUTHOR]

Alkali metal azides can be used as starting materials for the synthesis of polymeric nitrogen, a potential material of high energy density. In this letter, we report the ionic transport behavior in sodium azide under high pressure by in situ impedance spectroscopy and density functional theory calculations. The ionic transportation consists of ion transfer and Warburg diffusion processes. The ionic migration channels and barrier energy were given for the high-pressure phases. The enhanced ionic conductivity of the γ phase with pressure is because of the formation of space charge regions in the grain boundaries. This ionic conduction and grain boundary effect in NaN3 under pressures could shed light on the better understanding of the conduction mechanism of alkali azides and open up an area of research for polymeric nitrogen in these compounds and other high-energy-density polynitrides. [ABSTRACT FROM AUTHOR]

The dielectric behavior of polycrystalline CaMoO 4 was investigated at pressures up to 36.0 GPa using in situ impedance measurements. Grain boundaries played a dominant role in the electrical transport process. Grain boundary microstructures rearranged with the application of pressures, and the relaxation activation energy increased with increasing pressure in the tetragonal phase but decreased in the monoclinic phase. The variation of the bulk resistance with pressure was attributed to defects generated during the compression. The increasing grain boundary resistance with pressure in the tetragonal phase was caused by the increased number of dangling bonds. In the tetragonal phase, localization around O atoms weakened with increasing pressure, which promoted the polarization of Mo O electric diploes and led to an increase of the relative dielectric constant. In addition, the dielectric loss tangent of CaMoO 4 was significantly reduced in the low frequency range after a pressure cycle. This work demonstrates that regulation of the polycrystalline dielectric performance by modifying the grain boundary distribution under compression can be used as an effective method to improve the bulk properties of ABO 4 -type dielectrics. [ABSTRACT FROM AUTHOR]

A three-dimensional differential viscoelastic model combining the effects of curing degree, thermal expansion, chemical shrinkage and stress relaxation for composite laminates was established and well verified. The evolution of strain and stress of composite laminates during cure was numerically simulated using the validated model. Also, fiber Bragg grating temperature and strain sensors were adjacently embedded in the composite laminate to in situ monitor the temperature and strain evolution. The monitored strain was evaluated by comparison with the corresponding simulated strain. The results reveal that the monitored temperature can reflect the actual temperature evolution in composite laminates, whereas the monitored strain cannot accurately characterize the actual strain evolution in composite laminates at the early stage of cure. However, when the resin/grating interfacial bond strength increases enough to transfer resin strain effectively, the changes in the monitored strain can match well with the actual strain changes. [ABSTRACT FROM AUTHOR]

Nanoscale materials exhibit properties that are quite distinct from those of bulk materials because of their size restricted nature. Here, we investigated the high-pressure structural stability of cubic (C−type) nano-Eu 2 O 3 using in situ synchrotron X−ray diffraction (XRD), Raman and luminescence spectroscopy, and impedance spectra techniques. Our high-pressure XRD experimental results revealed a pressure-induced structural phase transition in nano−Eu 2 O 3 from the C−type phase (space group: Ia -3) to a hexagonal phase (A−type, space group: P -3 m 1). Our reported transition pressure (9.3 GPa) in nano-Eu 2 O 3 is higher than that of the corresponding bulk-Eu 2 O 3 (5.0 GPa), which is contrary to the preceding reported experimental result. After pressure release, the A−type phase of Eu 2 O 3 transforms into a new monoclinic phase (B−type, space group: C 2/ m ). Compared with bulk−Eu 2 O 3 , C-type and A-type nano−Eu 2 O 3 exhibits a larger bulk modulus. Our Raman and luminescence findings and XRD data provide consistent evidence of a pressure-induced structural phase transition in nano-Eu 2 O 3 . To our knowledge, we have performed the first high-pressure impedance spectra investigation on nano-Eu 2 O 3 to examine the effect of the structural phase transition on its transport properties. We propose that the resistance inflection exhibited at ∼12 GPa results from the phase boundary between the C−type and A−type phases. Besides, we summarized and discussed the structural evolution process by the phase diagram of lanthanide sesquioxides (Ln 2 O 3 ) under high pressure. [ABSTRACT FROM AUTHOR]

Unlike isotropic homogenous materials, 3D printing polymers are anisotropic in terms of their strength and fracture toughness properties, according to previous research. Therefore, the lowest strength must be accurately measured before the extensive application of any 3D printing materials. Certain 3D printing materials have been increasingly employed in large structures; therefore, the size effect of their strengths has become very important. In this work, we performed a systematic experimental investigation on the minimum strengths and size effects of four common 3D printing polymers made by fusion deposition modeling and injection molding. Three types of tensile specimens with very different cross-sectional areas were selected. For each material system, two types of specimens with different printing surface angles were employed. The results from 200 specimens demonstrated that the minimum tensile strengths in the build direction of some specimens were only 25% that of the other directions in the same specimens, and 59% of the injection-molded specimens composed of the same material. No general conclusion on the size effects of the tensile strengths could be made for most specimens. Only the strengths along the build direction decreased up to 72% in two types of specific specimens if their cross-sectional areas increased by 60 times. Although their strengths were anisotropic, the stiffness properties of the 3D printing polymers were isotropic. Digital image correlation measurements showed that the Young's moduli of all specimens composed of the same material were similar. A dual-notch mechanics model was employed to explain the anisotropic strengths, and a fractography analysis supported the size effect. [Display omitted] • Tensile strength along the build direction was the minimum strength. • No general conclusion on the size effects of the tensile strengths could be made. • Strengths decreased 72% in only PLA and PC specimens if their areas increased by 60 times. [ABSTRACT FROM AUTHOR]

This paper considers the robust and adaptive nonsingular terminal sliding mode (NTSM) control for a class of second-order uncertain systems. First, a new fast NTSM was proposed which had global fast convergence rate in the sliding phase. Then, a new form of robust NTSM controller was designed to handle a wider class of second-order uncertain systems. Moreover, an exponential-decline switching gain was introduced for chattering suppression. After that, a double sliding surfaces control scheme was constructed to combine the NTSM control with the adaptive technique. The benefit is that a strict demonstration can be given for the stagnation problem in the stability analysis of NTSM. Finally, a case study for tracking control of a variable-length pendulum was performed to verify the proposed controllers. [ABSTRACT FROM AUTHOR]

An efficient parallel algorithm for Caputo fractional reaction-diffusion equation with implicit finite-difference method is proposed in this paper. The parallel algorithm consists of a parallel solver for linear tridiagonal equations and parallel vector arithmetic operations. For the parallel solver, in order to solve the linear tridiagonal equations efficiently, a new tridiagonal reduced system is developed with an elimination method. The experimental results show that the parallel algorithm is in good agreement with the analytic solution. The parallel implementation with 16 parallel processes on two eight-core Intel Xeon E5-2670 CPUs is 14.55 times faster than the serial one on single Xeon E5-2670 core. [ABSTRACT FROM AUTHOR]

[Display omitted] Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) is an important virulence factor that blocks the host immune response and facilitates M. tuberculosis growth in host cells. MptpB inhibitors are potential components of tuberculosis combination treatment. Herein, we present the development of new biphenyls MptpB inhibitors with greatly improved MptpB inhibition based on our reported thiobarbiturate lead 6 by rational design with the structure-based strategy. The eight biphenyls bearing thiobarbiturate fragment target compounds showed more potent MptpB inhibition (IC 50 : 1.18–14.13 μM) than the lead compound 6. Further molecular docking studies showed that compounds 13 , 26 , 27 and 28 had multiple interactions with active sites. Among them, compound 13 exhibited dose-dependent increased antituberculosis activity in mouse macrophages. The results displayed that the strategy of modification utilizing biphenyl scaffold was efficient. Our study identifies biphenyls bearing thiobarbiturate fragment as new MptpB inhibitors and verifies the therapeutic potential of antimycobacterial agent targeting MptpB. [ABSTRACT FROM AUTHOR]

This paper considers the problem of robust adaptive trajectory tracking control for a wheeled mobile robot (WMR). First, the trajectory tracking of the WMR is converted to a problem of the stabilization of a double integral system. Next, a continuous finite-time control method is employed to design a tracking controller. Then, a disturbance observer and an adaptive compensator are designed to cooperate with the tracking controller for dealing with system uncertainties of the WMR. Finally, a switching adaptive law is presented in combination with the boundary layer approach to attenuate the chattering in the adaptive compensator. As a result, the control system yields the ultimate boundedness of both the tracking error and the adaptive gain. Simulation results demonstrate the validity of the new method. [ABSTRACT FROM AUTHOR]

Herein, an efficient pair of split G-quadruplex probes was selected (S/N = 21) to construct a simple, rapid and label-free technique for the detections of T4 DNA ligase and PNK activity. DNA ligase and PNK are engaged in DNA replication and repair, ensuring the genetic stability. The detections of T4 ligase and PNK activity are of great significance in biology and biomedicine. Split G-quadruplex probes are robust label-free biosensing tools with turn-on signal readout. The selected pair of split G-quadruplex probes combined with toehold-mediated strand displacement in this work demonstrated an efficient strategy for monitoring the activities of T4 DNA ligase and PNK with good sensitivity. [ABSTRACT FROM AUTHOR]

The high pressure electrical transport behavior of pentacene has been investigated by alternating current impedance techniques and direct current resistivity measurement in a diamond anvil cell (DAC). The resistance decreases with increasing pressure below 17.4 GPa, while it increases above 17.4 GPa, which is caused by the transition of pentacene from an ordered state to the disordered state under higher pressure. From the Raman spectra under various pressures, pentacene becomes amorphous above 17.3 GPa, which is consistent with the impedance results. The charge transport operates in the hopping regime with charges jumping between interacting molecules, and the hopping mechanisms are related to the vibration modes. Above 17.4 GPa, the pressure dependence of the relaxation activation energy is 21.7 meV/GPa and pentacene keeps semiconductor characteristics up to 28.3 GPa. [ABSTRACT FROM AUTHOR]

This study explored the relationship between graduate students' proactive personality and academic procrastination, and the chain-mediation by research self-efficacy and learning adaptability. Participants were 905 postgraduates in China (female =70%; first year =56%; humanities and social sciences =54%). They completed the graduate students' proactive personality scale, the graduate students' academic procrastination scale, the research self-efficacy scale, and the learning adaptability scale. Applying chain mediation analyses, results showed that proactive personality was associated with higher research self-efficacy and learning adaptability. Learning adaptability mediated the relationship between proactive personality and academic procrastination, specifically decreasing procrastination. Research self-efficacy and learning adaptability played a chain-mediating role between proactive personality and academic procrastination, with higher cumulative reduction of procrastination than with either self-efficacy and learning adaptability alone. These findings suggest a need for graduate student development and support services to aim at improving students' self-efficacy and learning adaptability for timely school completion, [ABSTRACT FROM AUTHOR]

Diamond holds promise for optoelectronic devices working in high-frequency, high-power and high-temperature environments, for example in some aspect of nuclear energetics industry processing and aerospace due to its wide bandgap (5.5 eV), ultimate thermal conductivity, high-pressure resistance, high radio frequency and high chemical stability. In the last several years, p-type B-doped diamond (BDD) has been fabricated to heterojunctions with all kinds of non-metal oxide (AlN, GaN, Si and carbon-based semiconductors) to form heterojunctions, which may be widely utilized in various optoelectronic device technology. This article discusses the application of diamond-based heterostructures and mainly writes about optoelectronic device fabrication, optoelectronic performance research, LEDs, photodetectors, and high-electron mobility transistor (HEMT) device applications based on diamond non-metal oxide (AlN, GaN, Si and carbon-based semiconductor) heterojunction. The discussion in this paper will provide a new scheme for the improvement of high-temperature diamond-based optoelectronics. [ABSTRACT FROM AUTHOR]

Highlights: [•] A simple method has been developed to detect the dielectric properties in a DAC. [•] The relative errors have been analyzed using the FEA method. [•] The configuration was evaluated by detecting the dielectric properties of KNbO3. [•] The decrease of permittivity in KNbO3 is caused by pressure-induced charge transfer. [ABSTRACT FROM AUTHOR]

Pressure-induced electrical transport properties of KNbO3 including resistance, relaxation frequency, and relative permittivity have been investigated under pressure up to 30.6 GPa by in situ impedance spectroscopy measurement. The results indicate that the discontinuous changes of these physical parameters occur around the structural phase transition pressure. The decrease of activation energy with increasing pressure reveals that the vibration damping of Nb-O dipoles is weakened in the orthorhombic and the tetragonal phases. The density of states and difference charge density calculations show that the pressure-induced charge transfer between the Nb and O atoms causes the relative permittivity change of KNbO3. [ABSTRACT FROM AUTHOR]

In recent decades, considerable evidence has emerged indicating the involvement of tRNA-derived fragments (tRFs) in cancer progression through various mechanisms. However, the biological effects and mechanisms of tRFs in lung adenocarcinoma (LUAD) remain unclear. In this study, we screen out tRF-29-79, a 5ʹ-tRF derived from tRNAGlyGCC, through profiling the tRF expressions in three pairs of LUAD tissues. We show that tRF-29-79 is downregulated in LUAD and downregulation of tRF-29-79 is associated with poorer prognosis. In vivo and in vitro assay reveal that tRF-29-79 inhibits proliferation, migration and invasion of LUAD cells. Mechanistically, we discovered that tRF-29-79 interacts with the RNA-binding protein PTBP1 and facilitates the transportation of PTBP1 from nucleus to cytoplasm, which regulates alternative splicing in the 3ʹ untranslated region (UTR) of SLC1A5 pre-mRNA. Given that SLC1A5 is a core transporter of glutamine, we proved that tRF-29-79 mediate glutamine metabolism of LUAD through affecting the stability of SLC1A5 mRNA, thus exerts its anticancer function. In summary, our findings uncover the novel mechanism that tRF-29-79 participates in glutamine metabolism through interacting with PTBP1 and regulating alternative splicing in the 3ʹ UTR of SLC1A5 pre-mRNA. [ABSTRACT FROM AUTHOR]

As a typical organic semiconductor material, rubrene plays a prominent role in the field of optoelectronic devices. Here, a notable photoluminescence (PL) and photocurrent enhancement of rubrene by 8‐ and 2.5‐fold is reported under compression, respectively. The shortening of the π−π stacking distance and the twisting of the lateral phenyl are crucial reasons for the decrease in the bandgap, resulting in the enhancement of PL emission and photocurrent. Pressure can effectively suppress the excitons transition from a free exciton state to a self‐trapped exciton state and improve the emission efficiency. The photocurrent is subject to dual regulation by bandgap and resistance. Interestingly, rubrene undergoes an electronic structure transition at about 4.8 GPa, which is responsible for the weakening of PL emission and photocurrent. This work provides a strategy for optimizing the performance of rubrene‐based optoelectronic devices and designing novel optoelectronic materials. [ABSTRACT FROM AUTHOR]

Sway modular steel structures with semi-rigid connections (SMSS-SRCs) have special configurations of connections and columns. Hence, current design requirements regarding effective length factors are unsuitable. Therefore, the displacement method was used to derive expressions for single-module lateral stiffness in the first, middle, and top stories, thereby obtaining the overall lateral stiffness of SMSS-SRCs. The negative lateral stiffness of the modular column was obtained by modifying the rotational constraints at both of its ends. Subsequently, the overall negative lateral stiffness of SMSS-SRCs was obtained as well. The story support factor was used to quantify the degree of mutual support between stories. Finally, formulas for calculating for the critical buckling load and effective length factors of columns in SMSS-SRCs were obtained. Finite element models were established to verify the proposed formulas. The results showed that the proposed method has good accuracy. Hence, this study could provide a reference for calculating the critical buckling load and effective length factor of columns in SMSS-SRCs. • Stability of sway modular steel structures with semi-rigid connections analyzed. • Formulas for the critical buckling load and effective length factors of columns in SMSS-SRCs were obtained. • Expressions derived for single-module lateral stiffness in different stories. • Finite element models were established to verify the proposed formulas. • Theoretical and numerical results showed good accuracy and safer predictions. [ABSTRACT FROM AUTHOR]

Factors promoting satisfaction and engagement with waste sorting were investigated. An extended theoretical model was established by integrating the theories of consumer satisfaction and customer engagement, rather than customer loyalty. Full replies to 672 valid questionnaires were obtained from respondents in 31 Chinese provinces. This paper explored how the perceived value of waste sorting, sorting facilities, income, age, and education affect waste sorting satisfaction. This paper also analyzed the effect of satisfaction on engagement in terms of enthusiasm, social interaction, and active participation by region and gender using multiple-group structural equation modeling (SEM). The results revealed perceived value of sorting and good sorting facilities can enhance satisfaction. Satisfaction can enhance enthusiasm, social interaction, and active participation. Education level, income and age would influence satisfaction and three dimensions of engagement: enthusiasm, social interaction and active participation. Waste sorting satisfaction affected enthusiasm, social interaction, active participation to a greater extent in eastern versus middle and western regions of China. It is important to provide market-incentives, such as green points reward, deposit refund, to promote household waste sorting. Image 1 • Education has the highest effect on enthusiasm (coefficient of 0.132) for males. • Facility has the highest positive impact on satisfaction for both genders. • Satisfaction positively impacts enthusiasm, social interaction and participation. • Income can enhance engagement of waste sorting for both genders. [ABSTRACT FROM AUTHOR]

The structure and electrical transport properties of molybdenum dioxide (MoO 2) under high pressure were studied by X-ray diffraction, in situ Hall effect and variable temperature electrical resistivity measurements. The X-ray diffraction measurements revealed two structural phase transitions at 14.3 GPa and 22.6 GPa, and unusual changes in the electrical parameters with pressure were attributed to these transitions. The internal conduction mechanism of MoO 2 under compression was explained by the Hall mobility and charge carrier concentration. The abnormal changes in the temperature coefficient reflected changes in the lattice thermal vibration trend. MoO 2 keeps a low temperature coefficient up to 34.4 GPa, showing good stable electrical transport performance. The results of this study will help guide the future development of pressure-modulated devices based on MoO 2. • Two structural phase transitions occurred around 14.3 and 22.6 GPa. • MoO 2 keeps a low temperature coefficient below 34.4 GPa. • The conduction mechanism under compression was investigated in a charge carriers level. [ABSTRACT FROM AUTHOR]

This work investigates the impact of pressure on the structural, optical properties, and electronic structure of CsPbBr3 quantum dots (QDs) using steady‐state photoluminescence, steady‐state absorption, and femtosecond transient absorption spectroscopy, reaching a maximum pressure of 3.38 GPa. The experimental results indicate that CsPbBr3 QDs undergo electronic state (ES) transitions from ES‐I to ES‐II and ES‐II to ES‐III at 0.38 and 1.08 GPa, respectively. Intriguingly, a mixed state of ES‐II and ES‐III is observed within the pressure range of 1.08–1.68 GPa. The pressure‐induced fluorescence quenching in ES‐II is attributed to enhanced defect trapping and reduced radiative recombination. Above 1.68 GPa, fluorescence vanishes entirely, attributed to the complete phase transformation from ES‐II to ES‐III in which radiative recombination becomes non‐existent. Notably, owing to stronger quantum confinement effects, CsPbBr3 QDs exhibit an impressive bandgap tuning range of 0.497 eV from 0 to 2.08 GPa, outperforming nanocrystals by 1.4 times and bulk counterparts by 11.3 times. Furthermore, this work analyzes various carrier dynamics processes in the pressure‐induced bandgap evolution and electron state transitions, and systematically studies the microphysical mechanisms of optical properties in CsPbBr3 QDs under pressure, offering insights for optimizing optical properties and designing novel materials. [ABSTRACT FROM AUTHOR]

Electron transfer (ET) process is considered a substantial factor in influencing the photoelectric conversion efficiency of optoelectronic devices. While pressure has demonstrated effective tune ET, a comprehensive investigation into the mechanisms for both restraining and promoting ET remains elusive. Herein, we have performed measurements using in situ high-pressure steady-state photoluminescence (PL), Raman scattering spectra, and femtosecond transient absorption (fs-TA) spectroscopy on InP/ZnS quantum dot–anthraquinone (InP/ZnS QD-AQ) complexes. The experimental results have demonstrated that the pressure-suppressed ET process in the InP/ZnS QD-AQ complexes arises from both the aggregation-induced emission (AIE) effect of AQ in toluene and the quantum confinement effect of the InP/ZnS QDs. The reduction in the distance between InP/ZnS QD and AQ under pressure emerges as a key factor that promotes the ET process in the InP/ZnS QD-AQ complexes. Furthermore, we observed that the pressure not only enhances the ET process but also suppresses the auger recombination process in liquid phase I of toluene, consequently leading to an enhancement in the photoelectric conversion efficiency. This study contributes to understanding the mechanism of the ultrafast dynamic processes in the pressure-induced QD-receptor complexes, and it has great potential for preparing efficient and stable optoelectronic devices. [ABSTRACT FROM AUTHOR]

In the past two decades Brillouin-based sensors have emerged as a newly-developed optical fiber sensing technology for distributed temperature and strain measurements. Among these, the Brillouin optical time domain reflectometer (BOTDR) has attracted more and more research attention, because of its exclusive advantages, including single-end access, simple system architecture, easy implementation and widespread field applications. It is realized mainly by injecting optical pulses into the fiber and detecting the Brillouin frequency shift (BFS), which is linearly related to the change of ambient temperature and axial strain of the sensing fiber. In this paper, the authors provide a review of new progress on performance improvement and applications of BOTDR in the last decade. Firstly, the recent advances in improving the performance of BOTDRs are summarized, such as spatial resolution, signal-to-noise ratio and measurement accuracy, measurement speed, cross sensitivity and other properties. Moreover, novel-type optical fibers bring new characteristics to optic fiber sensors, hence we introduce the different Brillouin sensing features of special fibers, mainly covering the plastic optical fiber, photonic crystal fiber, few-mode fiber and other special fibers. Additionally, we present a brief overview of BOTDR application scenarios in many industrial fields and intelligent perception, including structural health monitoring of large-range infrastructure, geological disaster prewarning and other applications. To conclude, we discuss several challenges and prospects in the future development of BOTDRs. [ABSTRACT FROM AUTHOR]

This paper investigates trajectory tracking control of a dielectric electro-active polymers (DEAP) actuator with hysteresis nonlinearity by using second-order adaptive discrete-time fast terminal sliding mode control (2-ADFTSMC) scheme. Taking into account that the hysteresis behaviour is asymmetric rate-dependent, a Hammerstein model is established to represent the DEAP actuator. Then, based on a novel 2-ADFTSM function and a terminal-sliding-mode-type switching control law, a 2-ADFTSMC scheme is proposed to improve the trajectory tracking performance. Furthermore, the stability of the closed-loop system is proved. Compared with discrete-time sliding mode control (DSMC) and discrete-time fast terminal sliding mode control (DFTSMC) schemes, the proposed control scheme can provide higher tracking accuracy, faster convergence speed, and stronger robustness in presence of model uncertainties and external disturbances. The effectiveness and practicality of the proposed control scheme are validated through the experiments on the DEAP actuator. [ABSTRACT FROM AUTHOR]