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• The resultant hydrogel possesses an admirable feature of mechanical robustness and excellent electrical performance. • The intriguing overall properties are attributed to the synergy of multiple physical interactions and nano-reinforcement. • The hydrogel delivers sensitive strain-induced resistance change under variational deformations. • A strain sensor based on such hydrogel can accurately monitor multi-scale deformations from large mechanical deformation to tiny physiological motions. For advanced conductive hydrogels, adaptable mechanical properties and high conductivity are essential requirements for practical application, e.g., soft electronic devices. Here, a straightforward strategy to develop a mechanically robust hydrogel with high conductivity by constructing complicated 3D structures composed of covalently cross-linked polymer network and two nanofillers with distinguishing dimensions is reported. The combination of one-dimensional quaternized cellulose nanofibrils (QACNF) and two-dimensional MXene nanosheets not only provides prominent and tunable mechanical properties modulated by materials composition, but results in electronically conductive path with high conductivity (1281 mS m–1). Owing to the uniform interconnectivity of network structure attributed to the strong macromolecular interaction and nano-reinforced effect, the resultant hydrogel exhibits a balanced mechanical feature, i.e., high tensile strength (449 kPa), remarkable stretchability (> 1700 %), and ultra-high toughness (5.46 MJ m–3), outperforming those of virgin one. Additionally, the enhanced conductive characteristic with the aid of QACNF enables hydrogels with impressive electromechanical behavior, containing high sensitivity (maximum gauge factor: 2.24), wide working range (0–1465 %), and fast response performance (response time: 141 ms, recover time: 140 ms). Benefiting from the excellent mechanical performance, a flexible strain sensor based on such conductive hydrogel can deliver an appealing sensing performance of monitoring multi-scale deformations, from large and monotonous mechanical deformation to tiny and complex physiological motions (e.g., joint movement and signature/vocal recognition). Together, the hydrogel material in this work opens up opportunities in the design and fabrication of advanced gel-based materials for emerging wearable electronics. [Display omitted] [ABSTRACT FROM AUTHOR]

The emerging graph convolutional network (GCN) provides a way to extract additional relationship information and has demonstrated superior performance in fault diagnosis. However, the GCN-based methods have some limitations when applied to cross-domain fault diagnostics. First, the graph topology constructed according to certain criteria remains fixed while it may contain domain-specific information, which could hamper the extraction of domain-invariant features. Second, the non-Euclidean structure of the graph hinders its augmentation through mixing and interpolation, bringing its application challenges in scenarios with small samples. To address these limitations, this article proposes an adaptive topology-aware siamese network (ATA-SN) for cross-domain fault diagnosis with small samples. Specifically, the multichannel data are constructed as a complete graph as input. The adaptive topology-aware module updates and augments the graph simultaneously through biased uncertainty edge perturbation in a nonparametric manner. In combination with a contrastive loss, augmented data with clear class boundaries can be obtained. A statistical metrics-based style loss is used for domain-invariant feature learning. A pair of updated graphs is then fed into the siamese framework, which utilizes the semantic consistency of the paired graphs to recalibrate the contribution of the augmented data to the gradient descent, thus ensuring the effectiveness of the graph augmentation and domain adaptation. Comparative studies and cross-domain fault diagnosis experiments indicate the superiority and effectiveness of the proposed method even in scenarios with extremely limited training data. The code of ATA-SN is released at https://github.com/CQU-ZixuChen/ATA-SN.

Graphical abstract:

The unsupervised domain adaptation (UDA) technique is aimed at minimizing the distribution discrepancy of interdomain (DDID) and, thus, bears immense potential for label scarcity in the target domain. Currently, most UDA methods frequently utilize pseudo labels to measure the distribution of target domain features. However, the level of pseudo labels in the reported studies is always modest, thus restricting the performance of UDA. To address the aforementioned deficiency, we develop an ensemble domain adaptation network (EDAN). It leverages ensemble learning (EL) to generate high-accuracy pseudo labels and couples domain adaptation (DA) as well as EL to guarantee pseudo labels’ robustness. Specifically, an EL network (ELN) with high generalization to the target domain is constructed based on multiple multiscale convolutional neural networks (CNNs) and a self-reinforce soft voting mechanism. Moreover, we dynamically couple ELN and the weighted balance distribution adaptation (WBDA) to upgrade EDAN’s classification stability, as well as the applicability of each CNN to the target domain. Twelve cross-condition fault diagnosis tasks and seven cross-device fault diagnosis tasks are designed based on four open-access rolling bearing datasets to verify the effectiveness of the proposed method. The research results indicate that EDAN outperforms five related approaches.

Caliper pipeline inspection gauges (PIGs) are essential devices for ensuring the safe operation of oil and gas pipelines. However, traditional caliper PIGs cannot detect multiple pipe deformations at one time, and the equipment components are complex and cannot be reused. With the continuous improvement of detection performance requirements in practical application fields, there is an urgent need for a detector that can accurately quantify deformation along the pipeline with a simple structure. To this end, a new type of flexible caliper PIG with strain sensors embedded in polyurethane caliper disks was designed, which is less disturbed by the internal environment of the pipeline. In this article, the theoretical model of the flexible gauging disk for the quantification of deformation is first presented. Then, the whole process of the flexible gauging disk through the dent is simulated by a finite element method, and the theoretical analysis is carried out by the dynamic model. Moreover, a flexible caliper sensor motion test bench is established to verify the feasibility and rationality of the proposed flexible detection method. Four experiments are designed to explore the factors affecting the precision of flexible caliper sensors. The experimental results demonstrate that the flexible caliper sensor can effectively detect the deformation defects in the pipe. The thickness, outer diameter, and material hardness of the flexible gauging disk have no significant impact on the detection accuracy, and the detection error increases with increasing running speed. Overall, this research provided a theoretical basis for the development of intelligent and efficient pipeline deformation inspection system.

Convolutional neural network (CNN)-based intelligent fault diagnosis approaches have showcased remarkable performance in the assessment of machine safety. The data monitored from mechanical systems in industries is primarily characterized by class imbalance. Nevertheless, most of the current CNN-based models are designed under the assumption of balanced sample distributions, which do not align with the prevalent conditions observed in real industrial scenarios. To tackle this challenge, a state-of-the-art multiattention-based feature aggregation convolutional network (MFACN) is developed in this study. The key contributions of this study are outlined as follows: 1) this study designs an attention-based multiscale module (AMM) and a multiscale feature aggregation module (MFAM) to facilitate comprehensive learning across multiple levels; 2) a robust CNN model based on AMM and MFAM is established. The constructed model can explore abundant information from mechanical signals; and 3) a dual focal loss (DFL) function is introduced to enhance diagnostic results under conditions of data imbalance. To assess the applicability of the proposed MFACN in machine health state identification, two experiments were conducted using the bearing dataset and the planetary gearbox dataset. The experimental results unequivocally show that MFACN surpasses seven other state-of-the-art approaches, especially when dealing with imbalanced datasets.

Enhanced adaptive empirical Fourier decomposition (EAEFD) is a recently developed single-channel signal separation algorithm, which has attracted increasing attention for diagnosing localized rolling bearing failures. Even though the EAEFD approach can extract the fault characteristic information from the vibration signals, it has limited capability to comprehensively and accurately represent the bearing condition characteristic information. To tackle the drawbacks of EAEFD, in this article, the multivariate EAEFD (MEAEFD) approach is proposed to deal with the mode separation problem of multichannel signals for rolling bearings and realize the self-adaptive synchronous analysis of multivariate signals. To better consider the feature information of each channel, the MEAEFD-based mechanical fault diagnosis method is further proposed by fusing the multichannel feature information on the basis of the MEAEFD approach. The proposed MEAEFD approach is compared with multivariate empirical mode decomposition (MEMD) and multivariate variational mode decomposition (MVMD) methods by the simulated and measured signal analysis, which indicates that MEAEFD method has a certain superiority in terms of decomposition accuracy and robustness, and the proposed approach has better diagnostic accuracy than the compared approaches.

Small-diameter artificial blood vessels are increasingly being used in clinical practice. However, these vessels are prone to thrombus, and it is necessary to improve blood compatibility. Surface coating is one of the commonly used methods in this regard. Inspired by the biomimicry of mussels, the use of deposition technology to obtain coating coverage on the surface of fibers has significantly piqued the interest of researchers recently. In this study, tubular scaffolds consisting of a composite of poly(caprolactone), cellulose acetate, and tannic acid (TA) were electrospun, and then the scaffolds were treated with different Fe(III) solutions (iron(III) chloride hexahydrate (FeCl3’6H2O)) to obtain four tubular scaffolds: F0, F5, F15, and F45. According to scanning electron microscopy (SEM) and field emission-SEM results, TA/Fe(III) complex is coated on the fiber of the scaffold after post-treatment; the fiber surface morphology changes with different Fe(III) concentrations. This provides designability to the performance of tubular scaffolds. The tensile strength of the F5 tubular scaffold (3.33 MPa) is higher than that of F45 (3.14 MPa), while the strain (83.9%) of the F45 tubular stent was 2.26 times that of the F5 (37.2%). In addition, cytotoxicity and antithrombotic performance were evaluated. The test results show that surface TA/Fe(III) coating treatment can affect the cytotoxicity and anticoagulation performance of the scaffold surface. The biomimetic TA/Fe(III) coating of mussels used in this study improves the performance of artificial blood vessels.

Regulation of the complex structure is greatly significant for the preparation of single-molecule magnets (SMMs). A Schiff base ligand, having suitably flexible coordination pockets, is usually designed to construct SMMs. In this text, three new homometallic complexes ([Dy(HL)2](NO3)·2H2O (Dy1), [Dy5(L)4(CH3CO2)6](CH3CO2)·6MeOH·H2O (Dy5), and [Dy6(L)2(L1)2(u3-OH)4(CF3SO3)6(EtOH)4]·2EtOH (Dy6)) were synthesized based on a Schiff base ligand, 6,6′-dimethoxy-2,2′-[4,5-dimethyl-o-phenylenebis(nitrilomethylidyne)]-diphenol (H2L), which has an N2O2pocket and a certain extent of steric hindrance. Their structures are characterized by single-crystal X-ray diffraction, and their magnetic properties are also explored. Complex Dy1is a double-decker structure in which the Dy ion is sandwiched by two HL–ligands. Complex Dy5displays a helical quadruple-decker structure which can be regarded as the structural extension of complex Dy1but this is terminated by the coordination of acetate groups. Complex Dy6is a centrosymmetric hexanuclear structure in which three Dy(III) ions construct an independent triangular plane. The new ligand L12–(H2L1= 2-(hydroxymethyl)-6-methoxyphenol) in complex Dy6is produced in situ from H2L under hydrothermal conditions. Magnetic studies on these complexes revealed that both Dy1and Dy6are typical SMMs, with a Ueff/kBvalue of 38.4 K for Dy1and 33.6 K for Dy6, respectively, and complex Dy5also shows SMM behavior under a zero dc field.

The prognosis of bearings is vital for condition-based maintenance of rotating machinery. This article proposes a systematic prognostic scheme for rolling element bearings. The proposed scheme infers the degradation progression by developing a novel health indicator (HI). This novel HI, derived from the spectral correlation, Wasserstein distance, and linear rectification, can reflect the changes in the probability distribution of all cyclic power-spectra over time. In other words, any form of variation in modulation characteristics can be revealed through the proposed novel indicator, even for the weak information buried by the internal or external noise. Furthermore, the developed HI can eliminate random fluctuations that often impair the remaining useful life (RUL) prediction accuracy. Then, a 3 ${\boldsymbol{\sigma }}$ criterion-based technique is introduced to divide health stages. After that, the gated recurrent unit network is employed to predict the RUL of the bearing system, integrated with the Bayesian optimization algorithm to tune the optimal hyperparameters adaptively. This renders the establishment of an intelligent prognosis model with high prediction accuracy and generalization ability. Finally, experimental validations are conducted using the run-to-failure datasets of bearings. The obtained results demonstrate that the proposed HI has better monotonicity, and the proposed prognostic scheme can predict the RUL with high accuracy.

Rotating machines are essential components in manufacturing, power generation, transportation, and aerospace industries. Nevertheless, most existing diagnosis methodologies are developed based on the assumption that machinery operates under stable conditions, which may limit their ability to uncover sufficient discriminative features when confronted with high noise levels. To tackle this issue, this article proposes a joint threshold learning convolutional network (JT-LCN) for rotating machinery diagnosis under nonstationary conditions. The major contributions of this research work can be summarized and highlighted as follows: 1) proposing a novel plug-and-play joint-thresholding module (JTM) that uses both soft and hard threshold mechanisms for intelligent signal denoising; 2) constructing an end-to-end network architecture, termed JT-LCN, which achieves a lightweight design through the use of depthwise separable convolution (DSC) and effectively purifies and identifies discriminative fault-related information by progressively using the JTM; and 3) introducing a dynamic self-knowledge distillation approach to enhance the generalization ability of the proposed network while minimizing computational costs and run-time memory requirements. Comprehensive experimental results conclusively demonstrate that the developed JT-LCN outperforms competition state-of-the-art approaches.

Small-diameter artery disease is the most common clinical occurrence, necessitating the development of small-diameter artificial blood vessels. In this study, seven types of poly(-caprolactone)–cellulose acetate (PCL–CA) composite nanofiber membranes were prepared with different proportions of PCL and CA. The adhesion and growth of Mc3t3-e1 cells were considered to confirm the in vitro cytocompatibility of PCL–CA membranes. A smooth stainless-steel mandrel with a diameter of 4 mm was used to roll up the prepared nanofiber membranes to produce the tubular scaffold with 50 °C hot water. The tubular scaffolds were subjected to axial and circumferential tensile tests. The mechanical performance of the PCL–CA tubular scaffold could be improved by increasing the layers. In addition, the burst pressure (BP) of the tubular scaffolds was increased with the layers, and the BPs of six-layer (2380 ± 36.8 mmHg) and eight-layer (3720 ± 80.5 mmHg) tubular scaffolds were much higher than that of the human saphenous vein (2000 mmHg). The compression shape memory performances of the PCL–CA tubular scaffold with different layers were also investigated to simulate and analyze the contraction and expansion of tubular scaffolds. The experimental results showed that the compression strain of the tubular scaffold in the diameter direction reached 35%, and the ultimate shape recovery rate reached 87%. However, the shape fixity rate and shape recovery rate increased, demonstrating that the optimum number of layers can improve the compression shape memory performance of the tubular scaffold. The results of this study, including comprehensive morphological and mechanical properties and cytocompatibility, indicated the potential applicability of PCL–CA tubular scaffolds as tissue engineering grafts.

Severe challenges are restraining the practical application of solid-state batteries, such as the dendrite growth and unsatisfactory compatibility between solid electrolyte and electrode. Here, we propose an interface dynamic control (IDC) strategy to ensure the stable operation of NASICON-based solid-state sodium batteries. First, we introduce intergranular phase (CuO) to effectively promote the densification of Na3Zr2Si2PO12with an optimized ionic conductivity of 1.74 × 10–3S cm–1at 25 °C. Moreover, the kinetically formed Na–Cu–O interlayer reveals outstanding conductive capability. The dramatically reduced interfacial area-specific resistance (70 ohm cm–2) boosts the resistance to Na dendrite growth, ensuring the excellent cycling stability of symmetric Na cells at a current density of 0.4 mA cm–2and room temperature. All-solid-state sodium metal batteries with Na3V1.5Cr0.5(PO4)3cathode and modified Na3Zr2Si2PO12ceramic electrolyte reveal a high retention of 87.4% at 100 mA g–1over 300 cycles. This work opens up a new route for the rational interface design of NASICON-structure solid electrolyte toward the application in the high energy-density and high safety electrochemical energy storage devices.

In this study, a finite element low-velocity impact model of Twaron®plain-woven fabric was created and analyzed using the commercial code ANSYS®-AUTODYN, and then was validated by drop-weight impact experiments. As a bullet or a fragment can strike a protective system from any angle in space, it is necessary to investigate fragment impact behavior response to impact threats from all angles of space. Therefore, in-plane obliquity θ, and spatial obliquity φ, were employed in this study and 17 different simulation test impact scenarios with different impact obliquity values were carried out using a standard hemispherical-head impactor. Results showed that the energy absorption of Twaron®fabric decreases with increasing θ, whereas under the same θ, the energy absorption increases with increasing φ. This study also evaluated and compared the low-velocity impact performance of Twaron®fabric as a function of impactor shape, such as hemispherical, flat, and ogival heads, with different θ. The results showed that under the same density, volume, and diameter conditions and at the normal impact scenario of a flat-head impactor, the fracture mechanism of the yarn is the same with all impact scenarios for a hemispherical-head impactor; the contacted yarns of the fabric fractured almost simultaneously. For the other oblique impact scenarios of the flat-head impactor, as well as impact scenarios of the ogival-head impactor, the yarns of the fabric fractured intermittently. Additionally, for the impact scenario with the ogival-head impactor, the effect of impact obliquity on energy absorption of the fabric was completely opposite to that of the hemispherical-head impact scenario. This is because in the hemispherical-head impact scenario, the fabric yarn tends to be damaged by tension, whereas in the ogival-head impact scenario, the fabric tends to be damaged by out-of-plane shear. These findings provide important guidance for the engineering of soft body armor and composite materials.

A semiconductor emitter can possibly achieve a sharp cutoff wavelength due to its intrinsic bandgap absorption and almost zero sub-bandgap emission without doping. A germanium-wafer-based selective emitter with front-side antireflection and backside metal coating is studied here for thermophotovoltaic (TPV) energy conversion. Optical simulation predicts the spectral emittance above 0.9 in the wavelengths from 1 to 1.85 µm and below 0.2 in the sub-bandgap range with a sharp cutoff around the bandgap, indicating superior spectral selectivity behavior. This is confirmed by excellent agreement with indirectly measured spectral emittance of the fabricated Ge-based selective emitter sample. Furthermore, the TPV efficiency by pairing the Ge-based selective emitter with a GaSb cell is theoretically analyzed at different temperatures. This Letter facilitates the development of the semiconductor-based selective emitters for enhancing TPV performance.

Non-alcoholic fatty liver disease (NAFLD) is an aberrant lipid metabolism disease. Hypoxia inducible factor-1 (HIF-1α) is a transcription factor which plays an important part in adapting lower oxygen condition. Here, we aimed to clarify the relationship between HIF-1α and NAFLD.

Melanin is ubiquitous in living organisms across different biological kingdoms of life, making it an important, natural biomaterial. Its presence in nature from microorganisms to higher animals and plants is attributed to the many functions of melanin, including pigmentation, radical scavenging, radiation protection, and thermal regulation. Generally, melanin is classified into five types—eumelanin, pheomelanin, neuromelanin, allomelanin, and pyomelanin—based on the various chemical precursors used in their biosynthesis. Despite its long history of study, the exact chemical makeup of melanin remains unclear, and it moreover has an inherent diversity and complexity of chemical structure, likely including many functions and properties that remain to be identified. Synthetic mimics have begun to play a broader role in unraveling structure and function relationships of natural melanins. In the past decade, polydopamine, which has served as the conventional form of synthetic eumelanin, has dominated the literature on melanin-based materials, while the synthetic analogues of other melanins have received far less attention. In this perspective, we will discuss the synthesis of melanin materials with a special focus beyond polydopamine. We will emphasize efforts to elucidate biosynthetic pathways and structural characterization approaches that can be harnessed to interrogate specific structure–function relationships, including electron paramagnetic resonance (EPR) and solid-state nuclear magnetic resonance (ssNMR) spectroscopy. We believe that this timely Perspective will introduce this class of biopolymer to the broader chemistry community, where we hope to stimulate new opportunities in novel, melanin-based poly-functional synthetic materials.

As interesting alternatives, electroactive actuators based on plasticized thermoplastic polyurethane (TPU) have shown their potential in developing soft robotics due to the large bending deformation, fast response, and good durability, especially their designable properties. Understanding the actuation mechanism is essential for controlling soft actuators as well as developing novel ones. In this work, the behaviors of the plasticizer and TPU membranes in electric fields were investigated and observed in situ by a microscope, showing that the plasticizer molecules migrated toward the anode of the actuator. It is found that there was a very thin plasticizer-rich layer formed in the material because of the accumulation of negatively charged plasticizer molecules, basing on the results of electrochemical impedance measurement and space charge measurement. This further led to a lower Young’s modulus but an internal electric field with a higher density in this layer, resulting in the deformation of the actuator. Furthermore, based on the actuation mechanism, some actuation characteristics of the developed soft actuators were clarified. The maximum deflection of these actuators increased with the number of cycle tests, and in each cycle test, the deflection quickly reached the maximum value and then gradually decreased. It is believed that these characteristics are strongly related to the behaviors of plasticizer molecules, which were investigated accordingly.

At present, China’s energy distribution and economic development are extremely unbalanced. In order to make rational use of resources, China has promoted the “west to East power transmission” and “north to South Power Transmission” pattern. HVDC transmission has obvious advantages in this long-distance transmission, but there are some shortcomings in the traditional LCC-HVDC system. Therefore, a new system LCL-HVDC is proposed. Firstly, some advantages of the system are introduced; secondly, LCC-HVDC and LCL-HVDC models are built in Simulink, in which the current distortion rate of valve side winding of converter transformer is measured; finally, compared with LCC-HVDC, the loss of LCL-HVDC converter transformer is studied by using method 2 recommended by IEEE standard, and the kn value of the new system is calculated.

Recent reports suggest that next-generation hair dyes might take inspiration from the natural pigment melanin. In humans, melanin imparts color to hair and skin and acts as a natural sunscreen and radical scavenger, thereby protecting lipids and proteins from damage. The most commonly employed synthetic mimic of melanin is polydopamine, and its successful deposition on human hair was recently reported. Herein, we describe an enzymatic approach to synthetic melanin for dyeing human hair in a process that closely mimics part of natural melanogenesis. This chemoenzymatic method avoids the addition of a base and enables the implementation of several monomers beyond dopamine, including tyrosine, tyramine, and their derivatives. Critically, the enzyme provides a milder process for producing coated hair fibers than conventional chemical hair dyeing methods. In addition to providing natural coloration, these coatings have the potential to act as protective sunscreens that prevent photodamage of the inner hair fibers during exposure to sunlight. The protocols developed herein represent a mild and efficient route to nature-inspired multifunctional coatings. Such materials are promising candidates for artificial hair pigmentation and, more generally, could find extensive application as functional fiber coatings.

Melanins are a family of heterogeneous biopolymers found ubiquitously across plant, animal, bacterial, and fungal kingdoms where they act variously as pigments and as radiation protection agents. There exist five multifunctional yet structurally and biosynthetically incompletely understood varieties of melanin: eumelanin, neuromelanin, pyomelanin, allomelanin, and pheomelanin. Although eumelanin and allomelanin have been the focus of most radiation protection studies to date, some research suggests that pheomelanin has a better absorption coefficient for X-rays than eumelanin. We reasoned that if a selenium enriched melanin existed, it would be a better X-ray protector than the sulfur-containing pheomelanin because the X-ray absorption coefficient is proportional to the fourth power of the atomic number (Z). Notably, selenium is an essential micronutrient, with the amino acid selenocysteine being genetically encoded in 25 natural human proteins. Therefore, we hypothesize that selenomelanin exists in nature, where it provides superior ionizing radiation protection to organisms compared to known melanins. Here we introduce this novel selenium analogue of pheomelanin through chemical and biosynthetic routes using selenocystine as a feedstock. The resulting selenomelanin is a structural mimic of pheomelanin. We found selenomelanin effectively prevented neonatal human epidermal keratinocytes (NHEK) from G2/M phase arrest under high-dose X-ray irradiation. Provocatively, this beneficial role of selenomelanin points to it as a sixth variety of yet to be discovered natural melanin.

This work proposes an approach to fabricate flexible transparent ultraviolet (UV)-shielding membrane by casting method, which uniformly disperses pristine zinc oxide nanoparticles (NPs) in low-density polyethylene (LDPE). The critical conditions for film fabrication, such as casting temperature, LDPE concentration in the solution, dissolution time, NP concentration, and post hot press cooling processes, are systematically studied. It is found that the casting temperature needs to be close to the melting temperature of LDPE, namely, 115°C, so that transparent film formation without cracks can be guaranteed. NP agglomerates are suppressed if the polymer concentration is controlled below 6%. For good dispersion of NPs, LDPE has to be swelled or unentangled enough in the solution (close to 200 h dissolution time), and then the NP agglomerates can be diminished due to the diffusion of the NPs into the polymer gel (322 h dissolution time). When the NPs are well-dispersed in the LDPE film, the film can completely shield UV light while allowing high transmissivity for the visible light. As the concentration of NPs in the film increases from 4 to 6%, the transmissivity of the film decreases, the tensile strength increases, and the tensile failure strain decreases.

A discrete tetrahedral indium cage, {[In12(μ3-OH)4(HCO2)24(tcma)4]} (In12-GL), was synthesized solvothermally by the reaction of indium nitrate with the tripodal tricarboxylic acid ligand N,N,N-tris{(2′-carboxy[1,1′-biphenyl]-4-yl)methyl}methylammonium chloride ([H3tcma]+Cl). This cage consists of four trimeric units [In3(μ3-OH)(μ2-CO2)3(μ2-HCO2)3] and four [tcma]2–ligands, which all perform as 3-connection nodes to bridge each other, resulting in a tetrahedral cage structure. The trimeric unit [In3(μ3-OH)(μ2-CO2)3(μ2-HCO2)3] is observed for the first time in the family of In-based metal–organic structures and can be considered as an evolution of a 6-connected [In3(μ3-O)(μ2-CO2)6] unit. Each In3+is terminally coordinated by a μ1-HCO2group. This cage contains potential Lewis acidic/basic active sites endowed by In3+ions as Lewis acidic sites and the uncoordinated oxygen atoms of μ1-HCO2moieties as Lewis basic sites and was explored as an effective heterogeneous catalyst in the cycloaddition of CO2with epoxides and the Strecker reaction for amino nitriles. These catalytic reactions were deduced to happen on the surface of the In12-GL cage.

The aim of this study was to validate the diagnostic efficacy of acoustic attenuation imaging (ATI) and ultrasonic shear wave elastography (SWE) in classifying nonalcoholic fatty liver disease (NAFLD). A total of 100 patients with NAFLD were recruited from our hospital between January 2021 and December 2022. Patient demographics and clinical data were collected, and 2-dimensional ultrasound was used to screen patients based on liver echo characteristics. Patients without liver space-occupying lesions underwent routine ultrasound examinations. Imaging or serology was used to confirm the presence of fatty liver in patients or healthy individuals. Patients with alcoholic liver disease (alcohol equivalent content < 20 g/day for women, <30 g/day for men), as well as those with lenticular degeneration, total parenteral nutrition, autoimmune liver disease, drug-induced hepatitis, and viral hepatitis, were excluded from the study. Out of the 100 included patients, 24 had normal liver, 21 had mild fatty liver, 30 had moderate fatty liver, and 25 had severe fatty liver. There were age differences between the normal group and patients with mild fatty liver, and the average body mass index (BMI) varied across the 4 groups. As the severity of the disease increased, the average BMI also increased (P< .05). The ATI scores and SWE scores differed significantly among the different groups (P< .05), with both scores showing an upward trend as the fatty liver condition worsened. Correlation analysis revealed positive correlations between ATI and SWE scores and the degree of fatty liver (P< .05), positive correlations with BMI (P< .05), and negative correlations with high-density lipoprotein cholesterol expression (P< .05). The area under the curve (AUC) for the ATI score in diagnosing different degrees of fatty liver was > 0.750, and the AUC for the SWE score was also > 0.750. The AUC for SWE score in diagnosing different degrees of fatty liver ranged from 1.01 to 4.57, while the combined AUC for ATI and SWE scores was > 0.850, with respective cutoff values of 3.62, 5.72, and 7.57 based on the maximum approximate entry index. The combination of ATI and SWE has a significant impact on the grading diagnosis of NAFLD, and its application can be extended to clinical practice.

BACKGROUND AND PURPOSE:Breast cancer is now recognized as a clinically heterogeneous disease with a wide spectrum of epidemiological and clinicopathologic features. We aimed to evaluate whether epidemiological and clinicopathologic features are associated with the histological tumor grade of breast carcinomas in Western China. METHODS:We retrospectively collected data from the Western China Clinical Cooperation Group and assessed associations between clinicopathologic factors and histological tumor grade in 8619 female breast cancer patients. Patients were divided into two groups: Group I (tumor grade I/II) and Group II (tumor grade III). Univariable analysis and multivariable logistic regression models were used to analyze the relationships between clinicopathologic factors and tumor grade. RESULTS:Patients presenting with positive axillary lymph nodes, large tumor size (>2 cm), lymphovascular invasion, hormone receptor negativity, human epidermal growth factor receptor 2 (HER-2) positivity, and triple negativity tended to have an increased risk of a high tumor grade. However, the number of pregnancies or births was inversely correlated with the risk of a high tumor grade. In addition, patients presenting with grade III tumors were more likely to receive aggressive treatment, such as adjuvant chemotherapy, anti–HER-2 therapy, and level III axillary lymph node dissection. CONCLUSIONS:Our results suggested that several clinicopathologic factors were associated with high tumor grade of breast cancer patients in Western China.

Barium titanate/graphene oxide/polyurethane (BTO@GO@PU) composite membranes for microwave absorption were designed and fabricated by mechanical-blending of BTO and GO in PU medium, followed by mold formation. The cross section morphology of the BTO@GO@PU membrane indicated that the BTO nanoparticles with 450 nm average diameter are successfully incorporated into the PU matrix. Mechanical tensile measurement showed that, as the amount of BTO nanoparticles increased from 5 wt% to 20 wt%, the elastic modulus of the corresponding membrane increased up to 23.0 MPa elongation with the elongation above 450 %. Microwave absorption property of the BTO@GO@PU membranes were evaluated by measuring its reflection loss in the frequency range of 0.1-18 GHz. With the addition of BTO up to 20 wt%, the maximum absorptivity of the composite reached up to 51 %. This is attributed to the dielectric loss of BTO nanoparticles.

The traditional approach toward improving the crystallization rate as well as the mechanical and barrier properties of poly(lactic acid) (PLA) is the incorporation of nanocelluloses (NCs). Unfortunately, little study has been focused on the influence of the differences in NC morphology and dimensions on the PLA property enhancement. Here, by HCOOH/HCl hydrolysis of lyocell fibers, microcrystalline cellulose (MCC), and ginger fibers, we unveil the preparation of cellulose nanospheres (CNS), rod-like cellulose nanocrystals (CNC), and cellulose nanofibers (CNF) with different aspect ratios, respectively. All the NC surfaces were chemically modified by Fischer esterification with hydrophobic formate groups to improve the NC dispersion in the PLA matrix. This study systematically compared CNS, CNC, and CNF as reinforcing agents to induce different kinds of heterogeneous nucleation and reinforce the effects on the properties of PLA. The incorporation of three NCs can greatly improve the PLA crystallization ability, thermal stability, and mechanical strength of nanocomposites. At the same NC loading level, the PLA/CNS showed the highest crystallinity (19.8 ± 0.4%) with a smaller spherulite size (33 ± 1.5 μm), indicating that CNS, with its high specific surface area, can induce a stronger heterogeneous nucleation effect on the PLA crystallization than CNC or CNF. Instead, compared to PLA, the PLA/CNF nanocomposites gave the largest Young’s modulus increase of 350 %, due to the larger aspect ratio/rigidity of CNF and their interlocking or percolation network caused by filler–matrix interfacial bonds. Furthermore, taking these factors of hydrogen bonding interaction, increased crystallinity, and interfacial tortuosity into account, the PLA/CNC nanocomposite films showed the best barrier property against water vapor and lowest migration levels in two liquid food simulates (well below 60 mg kg–1for required overall migration in packaging) than CNS- and CNF-based films. This comparative study was very beneficial for selecting reasonable nanocelluloses as nucleation/reinforcing agents in robust-barrier packaging biomaterials with outstanding mechanical and thermal performance.

Supramolecular aggregation has provided the archetype concept to understand the variants in an emerging systems property. Herein, we have achieved the supramolecular assembly of carbon nanodots (CDs) for the first time and employ supramolecular aggregation to understand their alteration in photophysical properties. In detail, we have employed the CDs as a block to construct the supramolecular assembly of aggregates in the CDs’ antisolvent of ethanol. The CD-based aggregates exhibit complex and organized morphologies with another long-wavelength excitation-dependent emission band. The experimental results and density functional theoretical calculations reveal that the supramolecular assembly of CDs can decrease the energy gap between the ground and excited states, contributing to the new long-wavelength excitation-dependent emission. The supramolecular aggregation can be employed as one universal strategy to manipulate and understand the luminescence of CDs. These findings cast new light to build the emerging systems and understand the light emission of CDs through supramolecular chemistry.

Solid oxide electrolysis cell (SOEC) is a promising electrochemical device for effectively and sustainably converting CO2into CO, and the development of SOEC depends on the exploitation of appropriate cathodes with good catalytic activity and stability. La0.75Sr0.25Cr0.5Mn0.5O3(LSCM)-based cathodes have been widely studied due to the excellent redox stability and good compatibility with other components of SOEC. La0.75Sr0.2Ca0.05Cr0.5Mn0.5O3(LSCCM) fabricated in our previous work shows a relatively satisfying electrocatalytic performance and is expected to be further optimized. Herein, Fe-doped LSCCM, La0.75Sr0.2Ca0.05Cr0.5Mn0.5−xFexO3(LSCCMFex, x = 0, 0.05, 0.1, 0.15, denoted as LSCCM, LSCCMFe5, LSCCMFe10, and LSCCMFe15, respectively) materials, are investigated as the cathodes for direct CO2electrolysis in SOEC. Specifically, LSCCMFe5 material shows a good chemical compatibility with Gd0.1Ce0.9O2-δ(GDC) electrolyte and excellent chemical stability in 30% CO/CO2atmosphere. Compared with the LSCCM electrode, the LSCCMFe5 cathode presents 30.5% decrease in polarization resistance for a half cell under pure CO2atmosphere at 800 ℃ and 42.3% increase in current density (0.60 A cm−2) for the direct CO2electrolysis of a single cell with an applied voltage of 1.6 V at 800 ℃. LSCCMFe5 exhibits a high electrocatalytic activity among various LSCM-based cathodes. The improvement in electrocatalytic performance could be due to the enhanced chemical adsorption of CO2and increased highly active O-/O22-species related to the newly generated oxygen vacancy via Fe-doping, leading to favorable surface reaction kinetics. Moreover, no degradation could be observed for the single cell after the direct CO2electrolysis test up to 100 h, suggesting an attractive competitiveness for the application of Fe-doped LSCCM cathodes to SOECs.

Plasma electrolytic oxidation (PEO) can reduce the corrosion susceptibility of Mg alloys by producing a protective oxide layer. The present investigation examined the influence of PEO processing parameters on the corrosion resistance of the resulting coatings. Changes in the oxidation time, applied current density, and electrolyte temperature were shown to alter the thickness of the coating as well as its phase composition. Increasing the coating time was found to increase the thickness and uniformity of the coating. Application of a greater current density was found to increase the thickness of the outer layer, resulting in a more porous structure with reduced corrosion resistance. Elevating the temperature of the electrolyte resulted in partial dissolution of the coating, producing a thinner coating than that produced in an electrolyte at a lower temperature. The resistance to corrosion initiation was considered to be related to through-film pores in the coating, via electrochemical impedance modelling.

SnO2-Sb2O5 coated Ti anodes can be used in the anodic oxidation of organic compounds for wastewater treatment. In this work, different SnO2-Sb2O5 anode compositions were fabricated using various techniques, such that the composition of the coating was varied from a SnO2-based to a Sb2O5 based material. These anodes were tested for the activity in the electro-oxidation of oxalic acid, which served as a model organic compound in wastewater. The activity of the anodes was correlated to the Sb doping level in the coating films. Specifically, the variation in the coverage of electrochemically active surface sites was explained by the arrangement of Sn and Sb on the SnO2 surface, and the catalytic activity in organic oxidation was related to the detailed mechanism of electro-catalysis, modeled by considering a two-step oxidation with surface adsorbed intermediates. The modeled kinetics helps explain the behavior of these anodes in the anodic oxidation of oxalic acid.

A data analysis method was developed for the interpretation of the electrochemical impedance spectra of electrodes with a layered structure. This method was successfully applied to the study of a layered titanium-supported antimony-tin oxide anode material which had an artificial passive layer. The time constant spectrum showed a distribution of resistance across a wide range of time constants associated with the non-stoichiometric structures of titanium oxide. From this spectrum, the resistance from the electrode material was extracted using deconvolution, and was found in agreement with the value estimated from the distortion of the cyclic voltammogram in ferrocyanide solution.

Three kinds of ceramic composites with laminar structure, B4C-B4C/Ti3SiC2, B4C-B4C/Ti2AlC and B4C-B4C/8%Si were synthesized by hot pressing sintering, respectively. The microstructures and properties of the composites were investigated in detail. The experimental results showed the two layers of each composite were in good combination and no spallation phenomenon was observed during the process of fracture. The fracture mechanism of three kinds of composites was similar with each other. The fracture mode of ceramic layers was mainly transgranular fracture. The ductile layers which showed good ductile fracture characteristic exhibited a mixed mode of intergranular and transgranular fracture. The results of mechanical properties showed the comprehensive performance of B4C-B4C/8%Si was the best, the flexural strength and fracture toughness of which were 524 MPa and 3.5 MPa∙m1/2 respectively.

Antimony-doped tin oxide anodes were fabricated from the thermal decomposition of tin chloride and antimony chloride. The surface and in-depth distribution of elemental compositions were analyzed using photoelectron spectroscopy. The results suggested that during the thermal treatment of the anodes, antimony preferentially was lost by evaporation, resulting in a composition that deviated from that nominally expected. Further electrochemical tests revealed that the composition in the antimony-doped tin oxide coatings had an impact on the conductivity of the anodes. Therefore, this study reveals that the evaporation loss of the precursor had an impact on the electrochemical activity of the antimony-doped tin oxide anodes.

A nitroso compound (R-NO) known as a "spin trap" was used to study the production of hydroxyl radicals (OH*) on a Ti/SnO2-Sb2O5 anode. A linear voltammetry study was conducted on this anode in the presence of this compound, using the rotating disk electrode technique. The results showed that the electrode started to produce (OH*) at 0.7V vs. Ag/AgCl reference electrode. The current was limited by the mass-transport of RNO in the electrolyte. When the voltage increased to 1.4V and higher, significant oxygen evolution took place. Further investigation was conducted by constant voltage electrolysis and spectroscopic measurement of the RNO concentration. The change in the RNO was interpreted as the evolution of (OH*), and the current efficiency was calculated based on the assumed stoichiometry. The results showed that the efficiency was optimal within the potential range 0.7-1.4V, and the highest efficiency could reach 30%. This was in agreement with the RDE experiment.

Introduction. Serine hydroxymethyltransferase 2 (SHMT2) has a critical role in serine-glycine metabolism to drive cancer cell proliferation. Yet, the function of SHMT2 in tumorigenesis, especially in human colorectal cancer (CRC) progression, remains largely unclear. Materials and Methods. CRC and paired normal samples were collected in the Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, and assessed by real-time polymerase chain reaction (qPCR) analysis, western blot (WB), and immunohistochemistry (IHC). Moreover, SHMT2 expression in human CRC cells was identified by qPCR and WB. The CRC cell proliferation, migration, and invasion after SHMT2 knockdown were explored through in vitro and in vivo assays. mRNA-seq assays were used to investigate the underlying mechanisms behind the SHMT2 function. Results. It was found that SHMT2 mRNA and protein were overexpressed in CRC tissue compared to the levels in normal mucosa. Positive expression of SHMT2 was significantly correlated with TNM stage and lymph node metastasis, and elevated expression of SHMT2 resulted as an independent prognostic factor in patients with CRC. SHMT2 knockdown impaired the proliferation of CRC in vitro and in vivo and induced cell cycle arrest by regulating UHRF1 expression. Conclusion. Taken together, our findings reveal that UHRF1 is a novel target gene of SHMT2, which can be used as a potential therapeutic strategy for CRC therapy.

A mixed metal-oxide anode material, Ti/SnO2-Sb2O5, is a candidate electrode for the electro-oxidation of organic compounds for treatment of wastewater. The catalytic efficiency of this material is dependent on both its surface morphology and surface chemistry. The surface chemistry was studied by photoelectron spectroscopy, and correlated with the electrochemical behavior through scanning voltammetry and impedance spectroscopy. The results showed that the surface activity of the anode material is dependent on the amount of antimony present. The mechanism of electro-catalysis with simultaneous oxygen evolution was also investigated, as this is an undesirable competitive reaction pathway.

Pyroelectric sensors based on PVDF polymers have great potentialities in the practical areas because of their great merits in the high converting efficiency from caloric or kinetic energy to the electric signal, as well as light-weight and flexibility. This work emphasized on the simulation of the PVDF pyroelectric sensor on the circuit level. The presented equivalent circuit model was simulated with the combination of the whole testing circuit in the environment of Multisim, so the simulated data could be comparable with the measured ones. And the validity of this PVDF sensor’s Multisim model was testified by the comparison with experimental data. Moreover, thermoelectric energy conversion was discussed by the extracted parameters in the equivalent circuit.

PAN-based carbon fiber (CF) was modified by electrochemistry using H2SO4 and maleic anhydride (MA) in current rearch. The CF surface morphology and natures were characterized by specific facilities, such as laser confocal microsopy (LCM), Fourier transform infrared spectroscopy (FTIR) and the degree of moisture. On the other hand, the biocompatibility nature was indicated by immobilization results of microorganisms on CF. The outcomes show that the surface hydrophilicity, oxygen-based function-groups and surface roughness of CF would contribute greatly to improve the immobilization ability of microorganisms on CF surface. And H2SO4 anodic oxidation on CF has more effect on microorganism immobilization than MA electropolymerization.

The mass transport of species, including diffusion, convection and migration, involved in the electro-oxidation of oxalic acid was investigated. A rotating-disk electrode technique was used as a tool to investigate the influence of convection. The effect of pH and potential on the degradation rate of oxalic acid was also investigated by measuring oxalic acid oxidation over the pH range 0 to 7 and potential 1.6 to 2.4 vs. Ag/AgCl. The results showed that higher degradation rates were achieved by increasing the convection, using higher pH and E. The results also showed that the local pH at the electrode surface had a significant impact on electrolysis in a neutral non-buffered solution.

Uniform BaTiO3nanotubes were synthesized via a simple wet chemical route at low temperature (50 °C). The as-synthesized BaTiO3nanotubes were characterized using powder X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The results show that the BaTiO3nanotubes formed a cubic phase with an average diameter of ∼10 nm and wall thickness of 3 nm at room temperature. The composition of the mixed solvent (ethanol and deionized water) was a key factor in the formation of these nanotubes; we discuss possible synthetic mechanisms. The microwave absorption properties of the BaTiO3nanotubes were studied at microwave frequencies between 0.5 and 15 GHz. The minimum reflection loss of the BaTiO3nanotubes/paraffin wax composite (BaTiO3nanotubes weight fraction = 70%) reached 21.8 dB (∼99.99% absorption) at 15 GHz, and the frequency bandwidth less than −10 dB is from 13.3 to 15 GHz. The excellent absorption property of BaTiO3nanotubes at high frequency indicates that these nanotubes could be promising microwave-absorbing materials.

The rhesus macaque (Macaca mulatta) is perhaps the most widely distributed nonhuman primate, is used more extensively than any other primate species as animal models for the study of biomedicine. In this study, we sequenced and analysed a fragment of 491 bp of mitochondrial DNA (mtDNA) partial control region in 230 individuals belonging to 8 populations of Sichuan province of China. Among the 230 individuals, we observed 56 different haplotypes defined by 110 polymorphic sites. The average number of nucleotide differences (k) was 18.844, indicating that very high genetic differentiation and the extant Sichuan wild rhesus macaques population consists of diverse genetic groups in their maternal lineage. The mtDNA haplotypes of these Sichuan wild rhesus macaques clustered into two main clades (CladeⅠand Clade Ⅱ), may correspond to M. m. vestitus and M.m.lasiotis.

Cross-species amplification of twenty-five SSR loci from the DNA of five rhesus macaques of diverse regional origins was conducted using human primers for the polymerase chain reaction (PCR). Seven of these primer pairs, which consistently and unambiguously amplified polymorphic fragments from these five samples, were also used to amplify SSR loci for 111 Sichuan wild rhesus macaques of five different populations. The analysed microsatellite markers produced 109 alleles, varied from 4 to 16 alleles each locus. The number of alleles per population ranged from 6.79 to 11.38. Polymorphic information content showed that all seven loci were highly informative (mean = 0.9017±0.0166, >0.5). The average observed heterozygosity was less than the expected (mean = 0.6795 and mean = 0.8559, respectively). Genetic differentiation among the populations was considerably low with the overall and pairwise FST values (mean = 0.0375), and showed fairly low level of inbreeding (indicated by a mean FIS value of 0. 0.1991). Maintaining genetic diversity is a major issue in conservation biology. In comparison to other captive Macaca mulatta studies, these wild rhesus macaque populations showed a relatively high level of genetic diversity, and there was low gene flow among these populations. Careful genetic management is important for maintaining genetic variability levels. None of the seven informative loci are linked which screened in this study can be applied in future studies on population and conservation genetics of natural primate populations.

To study the effect of Shengmai San (▪ Pulse-activating Powder) in protecting myocardium in the rat of the type 2 diabetic cardiomyopathy (DCM) model.

As a biofilm carrier for wastewater treatment, PAN-based carbon fiber (CF) was usually modified with different ways. The double modification treatment composed of surface oxidation and maleic anhydride (MA) graft was used in current research and it’s regarded to be a favorable surface treatment for CF carrier. The consequent CF surface morphology and natures were then characterized by laser confocal microscopy (LCM), X-ray photoelectron spectroscopy (XPS) and the degree of moisture. In addition, biocompatibility of CF was discussed through immobilization behavior of microorganisms. The results indicated that the immobilization ability of microorganisms will be improved if the CF surface is modified to better hydrophilicity by producing oxygen-based functionalities. Furthermore, the configurations and the adhesion forms of cells were affected by the properties of CF surface.

Electro-oxidation is a potentially efficient method to remove organic compounds commonly found in municipal wastewater. Compared to the conventional treatment by microbial digestion, electro-oxidation can offer significant saving in capital equipment, land footprint and treatment time. However, one of the biggest challenges facing this technology is to reduce the energy consumption associated with treatment. This work investigated the possible use of square-wave current pulsing as an electrolysis technique to improve the current efficiency. The experiments evaluated the efficiencies of electro-oxidation in simulated and actual wastewater. Two electrolysis modes, constant current and pulsing, were compared. The results indicate that the overall efficiency was dependent only on the average current, and there was no significant difference between pulsing and steady state electrolysis. This result suggests further study of the mass-transport characteristics of the organic compounds at the electrode-electrolyte interface.

Electromagnetic shielding effect material is needed because electronic devices suffer electromagnetic interference. Otherwise, in many engineering designs such as antenna fairings, sonar cover and stealth aircraft, materials with good electromagnetic penetration are desired. High performance fiber-reinforced composites have high specific strength and mechanical properties, and there is therefore a need to develop an electronics enclosure with optimum shielding by using a combination of particular fiber reinforcements and a polymer matrix. This paper describes the development of high-performance fiber-reinforced composites that use four high strength fibers (super fibers), Dyneema SK60 (an ultra-high molecular weight polyethylene fiber), Zylon HM (poly-p-phenylenebenzobisoxazole fiber), Technora T-241J (aramid fiber) and Torayca T800HB (carbon fiber). These super fibers were fabricated by compression molding and their shielding effectiveness (SE) was tested. The results showed that the newly developed Dyneema fiber, Zylon fiber and Technora fiber composites exhibited low electromagnetic shielding properties of 1.3~2.3 dB at a frequency of 0.5~18 GHz. Furthermore, the Torayca fiber composite has high electromagnetic shielding properties of 10.2~20.7 dB at the same frequency. It is expected that these high-strength composites with optimum SE can be obtained by controlling the electromagnetic shielding properties from hybrid multi-fiber structures.

Signals propagate on plate-like structures as ultrasonic guided waves, and analysis of Lamb waves has been widely used for on-line monitoring. In this study, the wave velocities of symmetric and anti-symmetric modes in various directions of propagation were investigated. Since the wave velocities of these two modes are different, it is possible to compute the difference in their arrival times when these waves propagated the distance from the vibration source to sensor. This paper presents an evaluation formulation of wave velocity and describes a generalized algorithm for locating a vibration source on a thin, laminated plate. With the different velocities of two modes based on Lamb wave dispersion, the method uses two sensors to locate the source on a semi-infinite interval of a plate. The experimental procedure supporting this method employs pencil lead breaks to simulate vibration sources on quasi-isotropic and unidirectional laminated plates. The transient signals generated in this way are transformed using a wavelet transform. The vibration source locations are then detected by utilizing the distinct wave velocities and arrival times of the symmetric and anti-symmetric wave modes. The method is an effective technique for identifying impact locations on plate-like structures.

The energy released from damages may give rise to small surface displacements and cause transient elastic waves in materials. Wave propagation of thin plates usually takes the form of lamb waves, and the modes of the lowest symmetric (S0) and anti-symmetric (A0) lamb waves are called the extensional and the flexural modes, respectively. In this study, a formulation, including the effect of shear deformation and rotary inertia, was derived to valuate the velocity of plate waves. The characteristics of plate wave propagation in thin laminated plates were investigated. Acoustic emission (AE) signals were generated by function generators and lead breaks, and propagated in laminated plates. These waves would be detected by broadband AE sensors because of their high sensitivity. With wavelet transform, AE waves were analyzed and the wave velocities of A0 and S0 modes were exactly calculated. Moreover, a simple method was presented to evaluate delamination in laminated plates. The length of delamination was predicted, and agreed well with the actual length.

Carbon nanotubes (CNTs) reinforced natural rubber (NR) composites with the CNT contents of 1, 3, 5, 10 and 20 wt% were synthesized using a solution casting method. The morphology of the composites was observed by scanning electron microscopy and Fourier transform infrared spectroscopy. It was found that CNTs were well distributed into NR and there was an excellent interface between CNTs and natural rubber. The mechanical properties of the composites were investigated by dynamic mechanical analysis (DMA) test and tensile test. It was found that the increment of storage modulus of NR/CNT composites was about 0.42 MPa/wt% in the rubbery state which agreed well with the results of tensile test. The large modulus increment confirmed the reinforcement effect of carbon nanotubes.