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The study proposes a Kalman Filter Family-schemed algorithm to identify the vehicle's parameters and evaluate the road roughness simultaneously, based on the response of an adapted monitoring vehicle. The vehicle is simplified as a three-dimensional multi-body system consisting of the unsprung mass of wheels and the sprung mass of the car body, connected by springs and dampers that represent the suspension system. Accelerometers and a gyroscope measure the accelerations or angular velocity of different positions of the vehicle during vibrations. The Kalman filter (KF) with unknown inputs enables the prediction of the car body's accelerations from those of wheels. On the other hand, the Augmented KF can compute the accelerations of wheels based on the car body's accelerations. Thus, an inner-systemic objective function incorporating the vehicle's parameter is built between the predicted and measured accelerations and solved in an optimized manner with the Genetic Algorithm, so that an individual complicated impact test or bump test is avoided. The numerical examples carry out field tests on a 900 m long standardized test road under two scenarios of with and without a bump. The road roughness estimated by these two KF methods from different measurements is used to calculate the International Roughness Index (IRI) and further the Riding Quality Index, which are compared with those directly provided by a standardized laser IRI profilometer. Accordance in between confirms the accuracy of the proposed algorithm under different scenarios. The analysis underlines the measurements from unsprung wheels that contact directly with the road enable a more accurate estimation of road roughness than those from the sprung car body. In addition, a vehicle speed lower than 40 km/h can provide a better estimation of the road profiles. [ABSTRACT FROM AUTHOR]

The evaluation of road roughness plays a critical role in the life-long maintenance of the highway system. This study proposes a Kalman Filter-based scheme to evaluate the road roughness indirectly from the response of a moving adapted monitoring vehicle. Key feature of the scheme is the use of measurements from dynamic tire pressure of unsprung mass components that directly interact with roads. Combination of ideal gas law and elastic contact model results in a nonlinear relationship between the tire pressure and the contact force, in which the parameters are calibrated by the Extended Kalman Filter. Identification of vehicle's physical parameters adopts the power spectrum method with a known-size bump test. Subsequently, the road roughness is treated as unknowns in the vehicle's state-space equation and solved by the Discrete Kalman Filter with unknown inputs. The estimated road roughness profiles are then used to calculate the International Roughness Index and compared with that provided by the standardized laser profilometer, an outer-systematic comparison. On the other hand, available measurements are split into groups that measurements of tire pressure are used to predict the accelerations of the car body and wheels and compared with these accelerations directly measured from accelerometers, an inner-systemic comparison. Field tests are carried out on a 900 m long standardized road under two scenarios of with and without the bump and four different vehicle running speeds from 20 to 50 km/h. Consistence of comparison from different perspectives proves the reliability of the proposed scheme. In addition, the results unveil that the scenario with a lower running speed can offer a better estimation of road roughness. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two novel unsymmetrical NTAamide ligands were developed for the An3+/Ln3+ separation. • The unsymmetrical NTAamide ligands show significantly higher extractability than NTAamide(n -Oct). • The extractability can be improved by shortening the chain length of the substituent. • A neutral complexation extraction model was determined by solvent extraction and complexation study. The efficient separation of trivalent actinides over lanthanides is a major challenge for the partitioning and transmutation (P&T) strategy in spent nuclear fuel reprocessing due to their very similar properties. In this context, the present work reports three amine-triamide NTAamides (nitrilotriacetamides), to investigate the influence of ligand structure on the extraction of Am3+ over Eu3+. Among the three ligands, N , N -diethyl- N ′, N ′, N″ , N″ -tetraoctylnitrilotriacetamide shows higher extraction ability for Am3+ compared with that of N , N -dibutyl- N ′, N′ , N″ , N″ -tetraoctylnitrilotriacetamide and N,N,N′,N′,N″,N″ -hexaoctylnitrilotriacetamide (NTAamide(n -Oct)) in the examined acid range of 0.01–0.50 mol/L HNO 3. The structure–activity relationship study reveals that the two unsymmetrical NTAamides with varying alkyl substituted groups have higher extraction efficiency to Am3+ and relatively lower selectivity for Am3+ over Eu3+ than the symmetrical NTAamide(n -Oct) due to the steric hindrance effect. The complexation study by means of slope analysis, ESI-MS, and UV–vis titration suggests the formation of 1:2 metal/NTAamide extracted species. Meanwhile, the NTAamide is identified as a tetradentate ligand by FT-IR and XPS analyses. Furthermore, the analysis of Raman and TRLFS indicates that the NO 3 − and the H 2 O molecule do not participate in the inner coordination sphere of Eu3+. By combining the results of solvent extraction and complexation, a neutral complexation extraction model is proposed. Additionally, the stability constants (log β) and thermodynamic parameters (Δ H , Δ S , and Δ G) regarding the complexation of Eu3+ with NTAamides are also presented. [ABSTRACT FROM AUTHOR]

Understanding how genes and experience work in concert to generate phenotypic variability will provide a better understanding of individuality. Here, we considered this in the main olfactory epithelium, a chemosensory structure with over a thousand distinct cell types in mice. We identified a subpopulation of olfactory sensory neurons, defined by receptor expression, whose abundances were sexually dimorphic. This subpopulation of olfactory sensory neurons was over- represented in sex-separated mice and robustly responsive to sex-specific semiochemicals. Sex- combined housing led to an attenuation of the dimorphic representations. Single-cell sequencing analysis revealed an axis of activity-dependent gene expression amongst a subset of the dimorphic OSN populations. Finally, the pro-apoptotic gene Baxwas necessary to generate the dimorphic representations. Altogether, our results suggest a role of experience and activity in influencing homeostatic mechanisms to generate a robust sexually dimorphic phenotype in the main olfactory epithelium. [ABSTRACT FROM AUTHOR]

Accumulation of extracellular amyloid-β (Aβ) in hippocampal subregions is a hallmark of Alzheimer's disease (AD), which promotes neuronal apoptosis, potentiates cognitive decline and play a causative role in AD pathogenesis. However, whether this process is controlled by distinct miRNAs at the posttranscriptional level remain fascinating but poorly understood. Using post mortem hippocampal samples from human AD patients and 3xTg-AD mouse, we demonstrate that miR-342-3p expression was significantly induced during the AD development. With the aid of intrahippocampal injection of miR-342-3p antagomir, we further show that in vivo miR-342-3p inhibition synergistically improved cognitive deficits in 3xTg-AD mice. The hippocampal Aβ-plaque burden in 3xTg-AD mice, as revealed by immunohistochemical analysis with 4G8 antibody, was attenuated also. Mechanistically, the upregulation of neuronal miR-342-3p is linked to an increase in the activation of the stress kinase c-Jun N-terminal kinase with the subsequent death of the neurons in Aβ-challenged HT22 hippocampal neuronal cells. These findings support the model that derangement of hippocampus signal transduction and subsequent neuronal apoptosis in AD arises as a consequence of increased Aβ burden and chronic activation of the JNK MAPK cascade in a miR-342-3p-dependent manner. Overall, we described for the first time the regulatory activity of miR-342-3p on relevant Aβ metabolism pathways in Alzheimer's disease. [ABSTRACT FROM AUTHOR]

The composition, phase transitions and isothermal oxidation dynamics of a new polycrystalline Ni-Cr-Co-W base superalloy are investigated using CALculation of PHAse Diagrams (CALPHAD), Differential Scanning Calorimetry (DSC), ThermoGravimetric analysis (TG/dTG), Scanning Electron Microscope and Energy Dispersion Spectrum (SEM/EDS) methods. The microstructure of the designed alloy shows a uniform γ matrix with the precipitates of rich-Ti cellular η and rich-Nb acicular platelet δ phase, and no Topologically Close-packed Phases (TCPs) observed, and the oxide behavior obeys a parabolic law with a parabolic constant ( k p ) 2.945 mg 2 /(cm 4 ·h) at isothermal 1300°C for 30 hours. The oxide scales are composed of an outer loose oxide mixture containing Cr, Ni, Ti and Nb/Ta and generous pores presented for a volatilization of Cr 2 O 3 , and a dense aluminum-rich oxide layer. [ABSTRACT FROM AUTHOR]

• Expression patterns of 10 DEGs were diametrically opposite in Z8R and Z8S group. • DHAV-3 infection results in cell growth suppression may be associated with IFITM1. • Conserved regions of IFITM1 (213–317 bp) could affected the cell cycle of DEF cells. Duck viral hepatitis (DVH) has a significant economic impact on duck industry, and duck hepatitis A virus genotype 3 (DHAV-3) is the most prevalent pathogen of DVH in Asian duck industry. The detailed study connecting differentially expressed genes (DEGs) and the differential resistance to DHAV-3 have not been accurately described, although a large numbers of DEGs have been identified by transcriptomic studies. Here, a resistant Pekin duck line (Z8R) and a susceptible Pekin duck line (Z8S) as models, high mortality and dramatically increased aspartate aminotransferase (AST), alanine aminotransferase (ALT) and the expression of immune-related genes of Z8S group were shown to be noticeable signs of cases caused by DHAV-3 infection. Compared with the control (Con) group, 1117 down-regulated DEGs and 612 up-regulated DEGs were found in the Z8S group and 37 down-regulated DEGs and 82 up-regulated DEGs were found in the Z8R group. Ultimately, the expression patterns of 10 DEGs were found to be diametrically opposite in Z8R and Z8S group. Functional analysis revealed that IFITM1 was associated with cell growth suppression, which was considered a key candidate gene. Results of flow cytometry showed that the conserved regions of IFITM1 (213–317 bp) could affected the cell cycle of duck embryo fibroblast (DEF) cells after infection with DHAV-3. Transcriptome and western blot analysis suggested that the CCND1, CCNE1 and CDK6 were significantly up-regulated in susceptible ducks by comparing with Con group. The hepatic injury and pathogenic outcomes caused by DHAV-3 infection were more severe in Z8S group compared to Z8R. Results of transcriptomics analysis and flow cytometry suggested that DHAV-3 infection can induce cell cycle changes that may be associated with IFITM1 expression level. These data will greatly enhance our understanding of the pathogenesis of DHAV-3 infection in ducklings and have implications for development of resistance breeding. [ABSTRACT FROM AUTHOR]

Femtosecond lasers (fs-lasers) offer a powerful and advantageous tool for fabricating a very large variety of materials. When processing transparent dielectrics, structural defects, such as cracks and broken edges, are always present, thus restricting the precision of fs-laser processing. In this paper, the formation and suppression mechanism of fs-laser induced structural defects are systematically studied. We demonstrate a novel method to improve the processing precision of lithium niobate (LiNbO 3) by elevating the substrate temperature. A crack-free ablation hole with a smooth edge was fabricated at the substrate temperature of 1000 ° C. Our results show that the increase of absorptivity and the suppression of incubation effects are responsible for the high precision processing at a high substrate temperature, which not only inhibits the formation of defects, but also additionally increases the efficiency of fs-laser processing. This work provides a simple method to efficiently suppress the defect formation induced by fs-laser in LiNbO 3 samples, paving the way for a new technique for high precision fs-laser processing. [ABSTRACT FROM AUTHOR]

In the process of ocean exploration, highly accurate and sensitive measurements of seawater temperature and pressure significantly impact the study of seawater's physical, chemical, and biological processes. In this paper, three different package structures, V-shape, square-shape, and semicircle-shape, are designed and fabricated, and an optical microfiber coupler combined Sagnac loop (OMCSL) is encapsulated in these structures with polydimethylsiloxane (PDMS). Then, the temperature and pressure response characteristics of the OMCSL, under different package structures, are analyzed by simulation and experiment. The experimental results show that structural change hardly affects temperature sensitivity, and square-shape has the highest pressure sensitivity. In addition, with an input error of 1% F.S., temperature and pressure errors were calculated, which shows that a semicircle-shape structure can increase the angle between lines in the sensitivity matrix method (SMM), and reduce the effect of the input error, thus optimizing the ill-conditioned matrix. Finally, this paper shows that using the machine learning method (MLM) effectively improves demodulation accuracy. In conclusion, this paper proposes to optimize the ill-conditioned matrix problem in SMM demodulation by improving sensitivity with structural optimization, which essentially explains the cause of the large errors for multiparameter cross-sensitivity. In addition, this paper proposes to use the MLM to solve the problem of large errors in the SMM, which provides a new method to solve the problem of the ill-conditioned matrix in SMM demodulation. These have practical implications for engineering an all-optical sensor that can be used for detection in the ocean environment. [ABSTRACT FROM AUTHOR]

A novel optical modulation method for stimulated Brillouin scattering (SBS) and the phase noise suppression in a remote interferometric fiber sensing system is proposed. Compared to the conventional phase modulation method to suppress SBS with only one phase modulation signal, another phase modulation signal with π shift is applied at the output end of the fiber, which converts the generated multi-frequency light to single-frequency light. Therefore the method can suppress not only SBS but also the phase noise induced by linewidth broadening owing to the first phase modulation. As a result, the method can keep the system a low phase noise level with a higher input power, which overcomes the conventional drawback of linewidth broadening. The results show a good reference to the design of remote interferometric fiber sensing systems. [ABSTRACT FROM AUTHOR]

Botulinum neurotoxin type A1 (BoNT/A1) is a potent protein toxin responsible for the potentially fatal human illness botulism. Notwithstanding, the long-lasting flaccid muscle paralysis caused by BoNT/A has led to its utility as a powerful and versatile bio-pharmaceutical. The flaccid paralysis is due to specific cleavage of neuronal SNAREs by BoNTs. However, actions of BoNTs on intoxicated neurons besides the cleavage of SNAREs have not been studied in detail. In this study we investigated by microarray analysis the effects of BoNT/A and a catalytically inactive derivative (BoNT/A ad) on the transcriptome of human induced pluripotent stem cell (hiPSC)-derived neurons at 2 days and 2 weeks after exposure. While there were only minor changes in expression levels at 2 days post exposure, at 2 weeks post exposure 492 genes were differentially expressed more than 2-fold in BoNT/A1-exposed cells when compared to non-exposed populations, and 682 genes were differentially expressed in BoNT/A ad-exposed cells. The vast majority of genes were similarly regulated in BoNT/A1 and BoNT/A ad-exposed neurons, and the few genes differentially regulated between BoNT/A1 and BoNT/A ad-exposed neurons were differentially expressed less than 3.5 fold. These data indicate a similar response of neurons to BoNT/A1 and BoNT/A ad exposure. The most highly regulated genes in cells exposed to either BoNT/A1 or BoNT/A ad are involved in neurite outgrowth and calcium channel sensitization. [ABSTRACT FROM AUTHOR]

Abstract: Large-scale few-layer graphene (FLG) films were prepared by an industrial single-roller melt spinning technique based on molten alloy quenched carbon self-segregation using nickel and carbon as precursors. A formation mechanism of FLG based on rapid diffusion and non-equilibrium segregation of carbon is discussed. This ultra-fast thin film preparation technique can be extended and used to produce ultrathin sheets of two-dimensional materials other than graphene. [Copyright &y& Elsevier]

Significant developments have been made in the navigation of autonomous mobile robots within indoor environments; however, there still remain challenges in the face of poor map construction accuracy and suboptimal path planning, which limit the practical applications of such robots. To solve these challenges, an enhanced Rao Blackwell Particle Filter (RBPF-SLAM) algorithm, called Lidar-based RBPF-SLAM (LRBPF-SLAM), is proposed. In LRBPF, the adjacent bit poses difference data from the 2D Lidar sensor which is used to replace the odometer data in the proposed distribution function, overcoming the vulnerability of the proposed distribution function to environmental disturbances, and thus enabling more accurate pose estimation of the robot. Additionally, a probabilistic guided search-based path planning algorithm, gravitation bidirectional rapidly exploring random tree (GBI-RRT), is also proposed, which incorporates a target bias sampling to efficiently guide nodes toward the goal and reduce ineffective searches. Finally, to further improve the efficiency of navigation, a path reorganization strategy aiming at eliminating low-quality nodes and improving the path curvature of the path is proposed. To validate the effectiveness of the proposed method, the improved algorithm is integrated into a mobile robot based on a ROS system and evaluated in simulations and field experiments. The results show that LRBPF-SLAM and GBI-RRT perform superior to the existing algorithms in various indoor environments. [ABSTRACT FROM AUTHOR]

Abstract: The novel specific structure of carbon nanotubers (CNTs) and the fascinating heterostructure of carbon nanotubers/metal nanostructure continue to attract attention for potential application and development in science and technology fields. Here, a special structure of CNTs (with small pits or holes on its walls) was fabricated by the combination of adorning the channel of anode alumina oxide (AAO) by electrochemical depositing metal Ag and growing of CNTs by chemical vapor deposition (CVD) and their structures details were characterized by transmission electron microscopy (TEM). The formation mechanism of this novel structure and its possible potential application are suggested. Furthermore, on the basis of this work, a novel heterostructure of Pt particles and carbon nanotubers was synthesized via similar approach. Regarding the latter, the approach presented here could be further extended to fabricate carbon nanotubes/other metal nanostructures. [Copyright &y& Elsevier]

Abstract: The B4C nanowires can be easily fabricated by employing an activated carbon, boron and Ni(NO3)2 whereas almost no B4C nanowires can be obtained if activated carbon is replaced by pure carbon. The analyses show that there are Si and Al impurities in the activated carbon, and both Si and Ni are critical to the growth of the B4C nanowires. Additionally, the yield of the B4C nanowires is greatly increased if the B4C nanowires are grown by the carbon nanotubes-confined method when Si is introduced. The mechanism of the Si enhanced growth of B4C nanowires is discussed. [Copyright &y& Elsevier]

Abstract: Polyurethanes were modified using monobenzyloxy polyethylene glycol (BPEG) which possesses a bulky hydrophobic benzyloxy group at one end and a hydroxyl group at the other end as a preconstructed BPEG layer, and poly(ethylene glycol) (PEG) and monomethoxyl poly(ethylene glycol) (MPEG) with various chain lengths as fillers. Our objective was to investigate the effect of PEG graft density and conformation on protein adsorption at PEGlated surface. The graft density was estimated by a chemical titration method. The combination of ATR-FTIR, AFM and titration results provide evidences that the graft density can be increased by backfilling PEG or MPEG to a BPEG layer. However, fibrinogen and albumin adsorption significantly increased on all surfaces after PEG or MPEG backfilling. We conclude that the conformation of hydrophobic benzyloxy end groups of the BPEG layer plays a key role. The benzyloxy end groups of preconstructed PEG chains stretch to the surface after PEG backfilling, which possibly accounts for the observed increase in protein adsorption. The BPEG conformation change after backfilling with PEG or MPEG was also suggested by contact angles. Additionally, protein adsorption was slightly influenced by the length of filler, suggesting a change in surface morphology. [Copyright &y& Elsevier]

The two DOTA-tetraamide ligands, DOTAM- n -butyl (1,4,7,10-tetrakis[(N - n -butyl; carbamoyl)methyl]-1,4,7,10-tetraazacyclododecane) and DOTAM-benzyl (1,4,7,10- tetrakis[(N -benzylcarbamoyl)methyl]-1,4,7,10-tetraazacyclododecane), were synthesized and characterized by MS, NMR and FTIR spectra. In acid solution, DOTAM- n -butyl was liable to be protonated. FTIR, 1H NMR, ESI-MS spectra and X-ray diffraction analyses revealed that the nitrogen atoms of cyclen ring combined two protons to form a cation with two positive charges. The protonated DOTAM- n -butyl had strong extraction ability and good selectivity for ReO 4 −. It was extracted by means of the substitution of one ReO 4 − for one NO 3 − in the 1:2 complex of DOTAM- n -butyl with HNO 3. The solvent extraction and X-ray crystallography demonstrated an anion-exchange extraction model. Meanwhile, X-ray crystal structure analyses of ligand complexes with HReO 4 or HNO 3 also indicated that ReO 4 − or NO 3 − ions were located in the gap between the upper and lower protonated ligands through multiple hydrogen bonds and electrostatic interactions. Image 1 • DOTA-tetraamide exhibited strong extraction ability and good selectivity for ReO 4 − separation in HNO 3 solution. • The single crystals for free ligand and its complexes with HNO 3 and HReO 4 were obtained for the first time. • An anion-exchange extraction model of ReO 4 − in HNO 3 solution by DOTA-tetraamide was determined. [ABSTRACT FROM AUTHOR]

Aim: The present study aimed to elucidate the potential function of microRNA 1228 (miR-1228) on the high glucose (HG)-damaged human renal proximal tubule cells (HK-2) and the underlying mechanism. Methods: The datasets GSE47185 and GSE51674 were downloaded from the Gene Expression Omnibus database for mining differently expressed mRNAs and miRNAs, respectively. Bioinformatics online tools were applied to predict the binding sites between miR-1228 and thrombospondin 2 (THBS2), which was confirmed by dual-luciferase assay. Real-time quantitative polymerase chain reaction was used to detect the mRNA level of miR-1228/THBS2. Western blot was used to detect the protein level of THBS2 and the PI3K/AKT signaling pathway-associated markers. HK-2 cells were cultured in HG (30 mM) to mimic hyperglycemia. Cell counting kit 8 and flow cytometry assays were utilized to determine the cell proliferation and apoptosis. Results: The expression of THBS2 was significantly upregulated in diabetic nephropathy (DN) based on bioinformatics tools and identified as a direct target of miR-1228. miR-1228 was downregulated in DN and HG-damaged HK-2 cells. HG notably reduced HK-2 cell proliferation. This negative effect was attenuated by transfecting with an miR-1228 mimic and aggravated by transfecting with an miR-1228 inhibitor. However, under basal condition, there was no significant effect on the HK-2 cell proliferation among blank control, mimic, and inhibitor groups. Overexpression of THBS2 abolished the elevating effect of the miR-1228 mimic on the HG-damaged HK-2 cell proliferation, while restored the inhibitory effects of the miR-1228 mimic on the cell apoptosis. On the contrary, the suppressive effects on the proliferation and the enhancive effects on the apoptosis by silencing miR-1228 in HK-2 cells stimulated with HG can be weakened by recommendation of THBS2 small interference RNAs. Furthermore, we also found that HG significantly enhanced the phosphorylation levels of PI3K and AKT. In terms of overexpression and knockdown experiments, Western blot analysis further revealed that miR-1228 inhibited the activation of the PI3K/AKT signaling pathway in HG-damaged HK-2 cells by regulating THBS2. Conclusion: The findings illustrated that miR-1228 improved survivability and inhibited apoptosis in HK-2 cells stimulated with HG partly by restraining the activation of the PI3K/AKT signaling pathway. [ABSTRACT FROM AUTHOR]

[Display omitted] • A DMES optimization model to boost renewable energy usage in data center is proposed. • A demand response model is built considered electricity price and renewable energy. • Monte Carlo and interval methods are combined to analyze effects of multi-uncertainty. • Model reduces costs by 1.85% but boosts renewable energy utilization by 0.77%. • Multi-uncertainty optimization increased DMES's costs but reduced operation risk. To address the increasing energy demands in data centers, distributed multi-energy system (DMES) can provide an efficient solution. This study proposes a DMES coupled by photovoltaics, wind turbines, ground source heat pump, internal combustion engines, electric chillers, absorption chillers, and energy storage device. The optimal scheduling of DMES with source-load interaction plays a crucial role in improving the performance of data centers. To achieve this, an integrated demand response (IDR) strategy is established, considering time-of-use pricing and renewable energy peak subsidies. Then, a clean and economical optimal operation model for DMES based on proposed IDR strategy and carbon trading mechanisms is established. Furthermore, to enhance the robustness of scheduling, this study analyzes the impacts of uncertainties in renewable energy output and demand response on DMES operation using the Monte Carlo method and interval method. Case study results demonstrate that the proposed IDR strategy increases electricity and cooling loads while reducing heat loads during the peak period of renewable energy generation, compared to the traditional IDR strategy. The proposed scheduling model, which incorporates the proposed IDR strategy and carbon trading mechanism, improves data center performance by reducing total costs by 1.85%, carbon emissions by 0.56%, electricity purchases by 2.93%, while increasing renewable energy utilization by 0.77%. The results also highlight the critical role of energy storage devices, with an optimal initial charge state is 0.5. Additionally, optimization considering multiple uncertainties, results in higher total costs and broader interval widths compared to single-factor uncertainty optimization, but reduces system operational risk. [ABSTRACT FROM AUTHOR]

This study develops and tests an automatic pixel-level image recognition model to reduce the amount of manual labor required to collect data for road maintenance. Firstly, images of six kinds of pavement distresses, namely, transverse cracks, longitudinal cracks, alligator cracks, block cracks, potholes, and patches, are collected from four asphalt highways in three provinces in China to build a labeled pixel-level dataset containing 10,097 images. Secondly, the U-net model, one of the most advanced deep neural networks for image segmentation, is combined with the ResNet neural network as the basic classification network to recognize distressed areas in the images. Data augmentation, batch normalization, momentum, transfer learning, and discriminative learning rates are used to train the model. Thirdly, the trained models are validated on the test dataset, and the results of experiments show the following: if the types of pavement distresses are not distinguished, the pixel accuracy (PA) values of the recognition models using ResNet-34 and ResNet-50 as basic classification networks are 97.336% and 95.772%, respectively, on the validation set. When the types of distresses are distinguished, the PA values of models using the two classification networks are 66.103% and 44.953%, respectively. For the model using ResNet-34, the category pixel accuracy (CPA) and intersection over union (IoU) of the identification of areas with no distress are 99.276% and 99.059%, respectively. For areas featuring distresses in the images, the CPA and IoU of the model are the highest for the identification of patches, at 82.774% and 73.778%, and are the lowest for alligator cracks, at 14.077% and 12.581%, respectively. [ABSTRACT FROM AUTHOR]

A novel water-soluble ligand of N,N,N‴,N‴ -tetraethyl- N ′ ,N ″-ethidene bisdiglycolamide (TEE-BisDGA) was synthesized and used as a masking agent for selective extraction of Am(III) over Eu(III) from HNO 3 solution by N,N,N ′, N ′ ,N ″ ,N ″-hexaoctylnitrilotriacetamide (NTAamide(C8)) in kerosene. Influences of acidity, concentration of water-soluble ligands and extractant as well as nitrate ions on the distribution ratios ( D ) and separation factors ( SF ) of Am(III) and Eu(III) were investigated. In the range of examined acidity from 0.001 to 0.2 mol/L, D Am and D Eu decreased with the increase of HNO 3 concentration. Using 0.1 mol/L NTAamide(C8) as an extractant, the maximum SF Am/Eu of 26 can be obtained in the presence of 0.01 mol/L TEE-BisDGA in aqueous phase with pH of 3.0, which was significantly higher than that case with no TEE-BisDGA. Job's method and mole ratio method were employed for extraction mechanism research. It has been shown that Am(III) and Eu(III) formed di-solvated species with TEE-BisDGA and mono-solvated species with NTAamide(C8), respectively. Moreover, the stability constants logβ values were obtained from UV–vis adsorption spectroscopic titration for Nd(III) complexes with TEE-BisDGA and N,N,N ′ ,N ′-tetraethyldiglycolamide (TEDGA), which indicated that TEDGA had a stronger complex ability than TEE-BisDGA. [ABSTRACT FROM AUTHOR]

The two-stage suspension system (TSSS) is designed for the fiber optic vector hydrophone (FOVH) to isolate the vibration from the mooring rope. The acceleration transmissibility of the TSSS is studied theoretically and experimentally. The results show that the TSSS has a major advantage over the traditional one-stage suspension system (OSSS). Typically, the vibration isolation of the TSSS is demonstrated to be over 25 dB higher than that of the OSSS at 100 Hz. Meanwhile, it is demonstrated that the TSSS has little negative influence on the in-band acceleration response of the FOVH. The TSSS has the prospect of reducing the mechanical noise of the FOVH, which is conducive to suppressing the self-noise and enhancing the ability of weak signal detection. [ABSTRACT FROM AUTHOR]

Modulation instability (MI) is the main limitation factor of the maximum optical power in long-haul phase-sensitive optical time domain reflectometry (Φ-OTDR), and induces signal fading and serious phase noise. In this paper, a method of coherent seed injection is proposed to suppress the MI-induced phase noise in long-haul Φ-OTDR. The spontaneous MI is suppressed by stimulating induced MI in an optical fiber. The visibility of the signal in Φ-OTDR is enhanced and the phase noise is suppressed significantly. This paper offers an effective method to increase the maximum input power with the MI-induced phase noise suppressed in the long-haul Φ-OTDR system. As a result, the maximum input power and sensing distance can be potentially increased, which is greatly beneficial to the enhancement of the performance of long-haul Φ-OTDR. [ABSTRACT FROM AUTHOR]

Thermal effect inevitably occurred in a bipolar membrane electrodialysis (BMED) stack impacts its energy efficiency and potentially damages non-metallic components. Up to now, thermal mechanism and impacts within a BMED stack remain incompletely understood. Thus, thermal mechanism and impacts within the stack were investigated using the validated equivalent circuit model of a BMED system. Its results revealed that currents/Joule effect in the main circuit were dominant compared to those in the external circuit. The proportion of Joule heat in the main circuit exceeds 99.00 %, while that in the external circuit was less than 1.00 %. Joule heat generated in the outermost slot of the maximum conductivity compartment was obvious, while that in any position of the main circuit within the minimum conductivity compartment was also significant. Thermal impacts of non-metallic components were affected by the heat transfer of solution thermal effect. Besides, these effects which included current distribution, Joule effect, and thermal risk, were mainly affected by the size of the element at spacer, and the conductance provided by the salt and its products. Larger size of slots/ducts at spacer reduced the heat transfer efficiency at their location, while that of main channel enhanced the heat transfer efficiency between membranes and solution. Low conductivity salts and corresponding products pose a greater thermal risk for BMED stack. Meanwhile, these effects would be aggravated from the lab- to large-scale BMED stack. These findings can enhance the comprehension of the involved processes for optimizing BMED technique, thereby accelerating its development. [Display omitted] • Thermal mechanism in a BMED stack was caused by current distribution of main/external circuit. • Thermal risk of non-metallic components was affected by heat transfer of solution thermal effect. • Larger size of slots at spacer reduced the heat transfer efficiency at their location. • Low conductivity salts and corresponding products pose a greater thermal risk for BMED stack. [ABSTRACT FROM AUTHOR]

• Vehicle modal parameters are identified using the free responses from the field tests of a vehicle passing over humps. • The road roughness can be estimated accurately using the measured vehicle responses from the field tests. • The proposed method can be easily and effectively performed with a few accelerometers only. Accurate information about vehicle parameters and road roughness is of great significance in vehicle dynamic analysis, road driving quality, etc. In this study, a method for estimating vehicle parameters and road roughness was developed using the measured vehicle responses from field tests which is efficient, economical, and accurate. First, the full-vehicle model was introduced. Then, vehicle modal parameters were identified using the consequent free responses of a vehicle passing over bumps. Second, the expression of the vehicle frequency response function (FRF) with respect to the wheel contact point was derived from the vehicle equation of motion, and a road roughness estimation method based on the vehicle FRF was developed. Third, field tests in which the vehicle passes over bumps were performed for vehicle model identification. Finally, field tests for road roughness estimation were carried out using a calibrated vehicle to verify the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]

The mammalian olfactory system uses a large family of odorant receptors (ORs) to detect and discriminate amongst a myriad of volatile odor molecules. Understanding odor coding requires comprehensive mapping between ORs and corresponding odors. We developed a means of high-throughput in vivo identification of OR repertoires responding to odorants using phosphorylated ribosome immunoprecipitation of mRNA from olfactory epithelium of odor-stimulated mice followed by RNA-Seq. This approach screened the endogenously expressed ORs against an odor in one set of experiments using awake and freely behaving mice. In combination with validations in a heterologous system, we identified sets of ORs for two odorants, acetophenone and 2,5-dihydro-2,4,5-trimethylthiazoline (TMT), encompassing 69 OR-odorant pairs. We also identified shared amino acid residues specific to the acetophenone or TMT receptors and developed models to predict receptor activation by acetophenone. Our results provide a method for understanding the combinatorial coding of odors in vivo. [ABSTRACT FROM AUTHOR]

The effect of die temperature on the mechanical performance and morphology of polyethylene (PE) pipe prepared via mandrel rotation extrusion is described. The experimental results showed that during the rotation extrusion of PE pipe, the hoop flow caused by the mandrel rotation was superimposed on the axial flow to deviate the formed shish-kebab from the axial direction which was favorable to improve the hoop strength of the PE pipe. However, high die temperature caused relaxation of most of the oriented molecular chains and the consequent formation of isotropic crystals in the PE pipe, whereas too low a die temperature led to imperfections in the PE pipe. As a result, there was an optimum temperature range for the enhancement of the hoop strength. When the mandrel rotated at 6 r/min, the hoop strength of the PE pipes prepared at the die temperature of 170°C reached the maximum value, 31.8 MPa, 22% and 29% higher than that at 150°C and 210°C, respectively. [ABSTRACT FROM AUTHOR]

To adapt to the complex application of polyurethane bearings, it is feasible to improve the tribological performance of single polyurethane-based friction materials through the synergistic effect produced by multi-component-lubricating fillers. In this context, rather than using tungsten disulfide (WS2), which has demonstrated excellent self-lubricating performance as a lubricating oil additive, this paper proposes that WS2 and single-walled carbon nanotubes (SWNTs) can be designed for addition into a polyether 4,4′-diphenylmethane diisocyanate (MDI) polyurethane matrix as self-lubricating fillers so as to explore the synergistic effect of micro- and nano-lubricating fillers on the tribological performance of polyurethane matrix materials. Through a series of characterizations and tests, it was found that the dispersion of two-component-lubricating additives in a polyurethane matrix is improved when the ratio of WS2 to SWNTs is roughly 2:1. In this case, the tribological performance of polyurethane matrix composites is more satisfactory than at other ratios. In addition, compared with the blank sample, the tribological performance of the synergistically modified polyurethane composites under dry friction is more significantly improved with the increase in contact load, while there is no significant improvement under water lubrication. Aside from contributing to the idea of exploring the synergistic effect of WS2 and other micro or nanofillers, this method also opens up the possibility of practically applying WS2 in the field of friction. [ABSTRACT FROM AUTHOR]

Background: With a pronounced and historically unprecedented tendency of population ageing, research on ageing and related disorders has been increasingly brought into focus. Horticultural therapy (HT), as an important role of social prescribing, has been an integrative for decades. This systematic review and meta-analysis aimed to evaluate HT for general health in older adults. Methods: Electronic databases including PubMed, Web of Science, ScienceDirect, the Cochrane Library, MEDLINE (Ovid), EMBASE (Ovid), CINAHL (EBSCO), China National Knowledge Infrastructure (CNKI), and the Wanfang database, grey literature databases and clinical trials registers were searched from inception to March 2021. Randomized controlled trials (RCTs), quasi-RCTs (QRCTs) and the cohort studies about HT for adults aged over 60 were included in this study. Outcome measures were physical function, quality of life, BMI, mood tested by self-reported questionnaire and the expression of the immune cells. The study was registered under PROSPERO (CRD42019146184). Results: Totally, fifteen studies (thirteen RCTs and two cohort studies) involving 1046 older participants were included. Meta-analysis showed that HT resulted in better quality of life (MD 2.09, 95% CI [1.33, 2.85], P<0. 01) and physical function (SMD 0.82, 95% [0.36, 1.29], P<0.01) compared with no-gardener; the similar findings showed in BMI (SMD -0.30, 95% [-0.57, -0.04], P = 0.02) and mood tested by self-reported questionnaire (SMD 2.80, 95% CI [1.82, 3.79], P<0. 01). And HT might be conducive on blood pressure and immunity, while all the evidence were moderate-quality judged by GRADE. Conclusions: HT may improve physical function and quality of life in older adults, reduce BMI and enhance positive mood. A suitable duration of HT may be between 60 to 120 minutes per week lasting 1.5 to 12 months. However, it remains unclear as to what constitutes an optimal recommendation. [ABSTRACT FROM AUTHOR]

Abstract: A test method for spherical mirrors with super-long radius of curvature that only one compensator is employed to measure the radii of curvature of both concave and convex mirrors is presented. With this testing system, the surface figure and radius of curvature of spherical mirrors can be measured simultaneously. Using the ABCD matrix method, a precise formula for radius of curvature calculation is deduced. Experimental results show that the relative measurement error of this method is less than 4.2×10−4. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to focus on the preparation of Kevlar fiber (KF) and alkaline hydrolyzed KF (KF-H) to improve the dispersed condition of polyaniline (PAn), as the aggregation of PAn would lead to some adsorption sites buried. And then the materials were used to enrich anionic dye Congo red (CR) from aqueous solution. Design/methodology/approach: The materials (KF@PAn and KF-H@PAn) were designed by means of "diffusion-interfacial-polymerization" under mild condition as high affinity due to the structural properties of PAn, KF and KF-H. The dispersed degree of PAn on the surface of KF and KF-H was validated according to adsorption efficiency for CR. Findings: The content of PAn introduced was not beyond 20 wt.%, while adsorption capacity for CR was significantly enhanced by 4–8 times (on the basis of kinetic data) according to the calculation only by the content of PAn due to KF and alkaline hydrolyzed KF exhibited almost no adsorption for CR, indicating dispersed situation of PAn coating was greatly enhanced and more active sites exposed, which was favorable for the adsorption process. Presence of NaCl would exhibit a more or less positive effect on CR uptake, suggesting the materials could be used for high salt environment. Research limitations/implications: The investigated means of dispersed degree of PAn on the surface of KF and KF-H are the further and future investigation. Practical implications: This study will provide a method to improve the dispersed situation of PAn and a theoretical support to treat anionic dyes from aqueous solution especially for salt environment. Originality/value: The results showed that the dispersed condition of PAn on the surface of KF and KF-H was greatly improved. According to the adsorption capacities for CR, it can be concluded that part of adsorption sites were buried due to the aggregation of PAn, and introduction of KF and KF-H, buried adsorption sites decreased greatly. This study will provide a method to decrease buried adsorption sites of PAn and a contribution for their convenient application in wastewater treatment especially for high salt environment. [ABSTRACT FROM AUTHOR]

Carbocysteine (H 2 ccys) wastewater, which contains H 2 ccys, chloroacetic acid, and ammonium chloride, can pose significant risks to the environment. In this study, a novel strategy was proposed for treating H 2 ccys wastewater by bipolar membrane electrodialysis (BMED) to realize resource recovery. The migration and coexistence mechanism of organic/inorganic ions in wastewater were investigated in lab-scale experiments. The results indicated that the desirable migration of inorganic ions, such as NH 4 + and Cl− ions, in the feed compartment were dominant. The undesirable migration of organic molecules, such as ClCH 2 COOH and H 2 ccys, could be managed through precise control of the BMED reaction process. To optimize the energy efficiency and thermal effect occurred in the pilot-scale, a two-stage BMED process was designed for treating H 2 ccys wastewater. The results revealed that BMED produced 1.33–1.63 M of HCl and 2.62–2.88 M of NH 3 ·H 2 O, and removed 90 wt% of NH 4 Cl from H 2 ccys wastewater. Meanwhile, the thermal effect of the slot at the outermost acid compartment decreased from 3.32 W in the one-stage BMED process to 0.10 W in the two-stage BMED process during the pilot-scale tests. The current efficiency of the two-stage BMED process for the acid/base production and feed desalination in the pilot-scale tests increased and its energy consumption decreased compared with the lab-scale tests. Moreover, the BMED r r ecycling route showed that a closed loop can be realized in the treatment of H 2 ccys wastewater, and its economic assessment showed that applying BMED to the treatment of H 2 ccys wastewater have economic benefits. These findings illustrated the feasibility of this novel strategy for treating H 2 ccys wastewater and laid a solid foundation for its industrialization. [Display omitted] • H 2 ccys wastewater treated by BMED process was investigated from lab-to pilot-scale. • Migration and coexistence mechanism of the ions in H 2 ccys wastewater were identified. • Novel concept of the stack design that prioritizes thermal effects was initially applied. • In situ application route of BMED products was established on the basis of recycling concept. • Economy of utilizing BMED to treat H 2 ccys wastewater was assessed. [ABSTRACT FROM AUTHOR]

Selective serotonin reuptake inhibitors (SSRIs) are first-line antidepressants, however, only around 60% of patients could benefit from them. Acupuncture is supported by insufficient evidence to help with symptom relieving and SSRIs tolerance. This pragmatic randomized controlled trial compared SSRIs alone versus SSRIs together with manual acupuncture (MA) or electroacupuncture (EA) in moderate to severe depressed patients. Patients were randomly allocated to receive MA + SSRIs (161), EA + SSRIs (160), or SSRIs alone (156) for six weeks, and then followed up for another four weeks. The primary outcome was response rate of the 17-item Hamilton Depression Scale (HAMD-17) at 6th week. The secondary outcomes were HAMD-17 (remission rate, early onset rate, total score), Self-Rating Depression Scale (SDS: total score), Clinical Global Impression (CGI), Rating Scale for Side Effects (SERS: total and domain scores), number of patients with adjusted dosage of SSRIs and adverse events (AEs). Both MA + SSRIs and EA + SSRIs were significantly better than SSRIs at 6th week on HAMD-17 response rate (RR = 1.21, 95% CI 1.04, 1.42, P = 0.013; RR = 1.27, 95% CI 1.09, 1.48, P = 0.0014), HAMD-17 early onset rate (P < 0.0001), HAMD-17 and SDS total scores (P < 0.05), CGI (P < 0.01), SERS total score (P < 0.01), number of patients with increased dosage of SSRIs (P < 0.01). For HAMD-17 remission rate, EA + SSRIs was significantly higher than SSRIs (P = 0.0083), while MA + SSRIs showed no significant difference at 6th week (P = 0.092). No unintended acupuncture-related severe AE was observed. This study identified that both MA and EA showed beneficial effects in addition to SSRIs alone in patients with moderate to severe depression, and were well tolerated. Clinical trials registration: ChiCTR-TRC-08000297. [ABSTRACT FROM AUTHOR]

In this work, a unique Ppy@NiCo 2 S 4 core-shell heterostructure material is prepared taking polypyrrole (Ppy) nanotubes as skeleton through a simple and environmentally friendly hydrothermal method. The heterostructured structure with Ppy nanotubes (NTs) as the core and intertwined flake-like NiCo 2 S 4 as the outer shell, holds a large specific surface area (217 m 2 g −1 ), convenient charge transport channel, high specific capacitance (908.1 F g −1 at a current density of 1 A g −1 ), and excellent cycling performance (87.7% of initial value is retained after 2000 cycles). What’s more, an asymmetric supercapacitor is fabricated by employing Ppy@NiCo 2 S 4 core-shell heterostructured material as positive and nitrogen-doped carbon nanotubes (N-C NTs) as negative electrode. This Ppy@NiCo 2 S 4 //N-C asymmetric supercapacitor effectively provides a high energy density over 50.82 Wh kg −1 with a high power density of 160 W kg −1 and preeminent cyclic stability of 126.6% after 2000 cycles. Due to the introduction of one-dimensional flexible Ppy inner core, as-designed the core-shell heterostructure composite may be promising in the flexible energy storage devices. [ABSTRACT FROM AUTHOR]

This paper develops an approach that estimates the range and depth of a broadband source by adopting the vector hydrophone vertical array (VHVA) in the deep ocean. The sound field in the direct wave zone is mainly composed of direct (D) and once-sea-surface-reflected (S1B0) waves. The arrival angles and time delays of the two waves are consistent. The combined beamforming technology is applied to the VHVA to accurately obtain the elevation angles and further enhance the received signal-to-noise ratio (SNR). The source ranges are then estimated according to the simple geometric relationship. The source depth estimation model is established based on the Lloyd-mirror principle, which relates the interference properties of D and S1B0 to the oscillation period of the combined signals of VHVA. The feasibility and availability of this method are validated by both simulations and sea trials in the South China Sea. The experimental results indicate the range estimation error of the moving vessel is less than 10% and the surface or submerged targets can be effectively determined. Our proposed algorithm has the strong benefits of simple principle, low computational complexity and small error. These properties indicate this algorithm can be used in target detection in the deep sea. • Applying the combined beamforming to the vector hydrophone vertical array to estimate elevation angle more accurately. • Providing a simple method for range and depth estimation. • Range estimation error of a moving vessel is less than 10% in the direct zone. • Recognizing surface or submerged targets effectively at moderate ranges. • Valuable deep-sea data in the experiment. [ABSTRACT FROM AUTHOR]

Two diglycolamide homologs, N,N,N′,N′-tetraoctyl-3,6-dioxaoctane diamide (DOODA) and N,N,N′,N′-tetraoctyl-3,6,9-trioxaundecane diamide (TOUDA), were synthesized. Their extraction behaviors of Am and Eu were investigated and compared with those of N,N,N′,N′-tetraoctyl-3-oxapentane diamide (TODGA). The extraction ability toward Am and Eu decreased with increasing etheric oxygen number in the extractant structure. In contrast to TODGA, an very interesting inversion on the selectivity occurred for DOODA and TOUDA, which were more favor of extracting Am than Eu. The maximum SF of 3.5 for DOODA can be achieved at 3.0 mol/L HNO. The stoichiometries of extracted species and extraction thermodynamic parameters were also presented. Graphical Abstract: [ABSTRACT FROM AUTHOR]

EP3 is a receptor for prostaglandin E2 (PGE2), and although its effect on bladder excitability has attracted considerable attention, the underlying mechanism remains unclear. To investigate whether the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in the interstitial cells of Cajal (ICCs) of the bladder are involved in the effect of EP3 activation on bladder excitability, wild-type mice, HCN1 knockout (HCN1 −/− ) mice and rats were used in our study. Double immunofluorescence staining and immunoprecipitation assays demonstrated the interaction between EP3 and the HCN channels. Sulprostone is a selective agonist of EP3. The current density of HCN channels was enhanced by sulprostone or PGE2 using whole-cell patch clamping. Western blot analyses showed that the expression levels of HCN1 and HCN4 were higher in bladders that had undergone intravesical instillation with sulprostone than in bladders treated with normal saline (NS). Both PGE2 and sulprostone increased the calcium concentration of the ICCs, and their effects were inhibited by ZD7288 (antagonist of HCN channels) treatment. In bladder detrusor strip testing, both PGE2 and sulprostone enhanced the amplitude of the bladder detrusor in HCN1 −/− mice; however, these effects were less than those in the wild-type mice. Furthermore, the effects of PGE2 and sulprostone were inhibited by ZD7288. Taken together, our results indicate that EP3 is expressed in bladder ICCs and facilitates bladder excitability via HCN channels. This study provides more comprehensive insights into the mechanism between inflammation and bladder excitability and highlights methods that can resolve bladder hyperactivity. [ABSTRACT FROM AUTHOR]

To clarify the structure-property relationships of pyridylpyrazole ligands and provide guidance for the design of new and more efficient ligands for the selective extraction of actinides over lanthanides, a series of alkyl-substituted pyridylpyrazole ligands with different branched chains at different positions of the pyrazole ring were synthesized. Extraction experiments showed that the pyridylpyrazole ligands exhibited good selective extraction abilities for AmIII ions, and the steric effects of the branched chain had a significant impact on the distribution ratios of AmIII and EuIII ions as well as the separation factor. Moreover, both slope analyses and UV/Vis spectrometry titrations indicated the formation of a 1:1 complex of 2-(1-octyl-1 H-pyrazol-3-yl)pyridine (C8-PypzH) with EuIII ions. The stability constant (log K) for this complex obtained from the UV/Vis titration was 4.45 ± 0.04. Single crystals of the complexes of 3-(2-pyridyl)pyrazole (PypzH) with Eu(NO3)3 and Sm(NO3)3 were obtained; PypzH acts as a bidentate ligand in the crystal structures, and the N atom with a bound H atom did not participate in the coordination. In general, this study revealed some interesting findings on the effects of the alkyl-chain structure and the special complexation between pyridylpyrazole ligands and LnIII ions. [ABSTRACT FROM AUTHOR]

Accurate vehicle parameter information plays an important role in assessing the conditions of roads and bridges, along with the corresponding maintenance. This study considered a vehicle parameter identification method based on a vehicle frequency response function (FRF). First, the vehicle FRF was deduced with respect to the displacements of the vehicle-road contact points, thereby building the relationships among the FRF, vehicle responses, and road profile in the frequency domain. Next, using the responses of vehicles passing over on-road bumps of known size, a direct estimation of the vehicle FRF was described. Then, a combination of Tikhonov regularization and a shape function method was used to update the estimated vehicle FRF by removing the singular data owing to the direct computation of the vehicle FRF. Subsequently, the modifying factors of the vehicle parameters were iteratively identified based on a sensitivity analysis of the estimated FRF to the vehicle parameters. A numerical simulation for vehicle parameter identification was performed to test the effectiveness of the proposed methods, considering a 5% Gaussian noise pollution and the influences of different driving speeds. At last, field tests of a vehicle passing over bumps were performed for the verification of vehicle parameter identification. [ABSTRACT FROM AUTHOR]

[Display omitted] • The polyethylene glycol brush grafted from nitrile butadiene rubber is successfully prepared and characterized with the reactive site found. • The brush improves the tribological performance of NBR, with coefficient of friction reduced by 73.4% at 100 rpm in particular. • The Fast Sample Entropy Diagram is proposed to analyze the friction-induced vibration visually. The water-lubricated bearing will be in a state of poor lubrication when marine stern shafts operate under low speed and heavy load conditions, which could cause severe wear and vibration, endangering the stealth performance of underwater vehicles. In this study, the grafting of polyethylene glycol brush was carried out on the surface of nitrile butadiene rubber (PEG-g-sNBR) by "grafting from" method. Fourier-transform-infrared-spectroscopy, nuclear-magnetic-resonance, and scanning-electron- microscope results demonstrated that the PEG-g-sNBR brush was successfully synthesized, and the reactive site was found. Using a tribological test machine with a high-precision vibration acceleration sensor, the tribological behaviors of PEG-g-sNBR were studied under aqueous lubrication. The results showed that the coefficient of friction of PEG-g-sNBR was reduced by 73.4% at 100 rpm compared to pure NBR, its microscopic wear and vibrational energy were also lower than pure NBR. Moreover, the lubrication states were revealed by friction, wear, together with the complexity of friction-induced vibration signal time series, and a lubricating film was formed on the friction surface of PEG-g-sNBR at lower rotational speed. In addition, the PEG-g-sNBR could work stably for 12 h at 300 rpm, and still maintain good tribological performance. [ABSTRACT FROM AUTHOR]

When marine stern shafts operate under low speed and heavy load conditions, the metal shaft and water-lubricated bearing will be in a state of boundary lubrication or even dry friction. Poor lubrication can cause severe wear and friction-induced vibration, endangering the stealth performance of underwater vehicles. In this study, several typical liquid lubricants, including liquid paraffin, tung oil (TO), dimethyl silicone oil (DSO), ionic liquid (IL), and hexamethylene diisocyanate (HDI) were selected as the surface coatings for nitrile butadiene rubber (NBR). Using a tribological test machine with a high-precision vibration acceleration sensor, as well as scanning electron microscopy (SEM) and other techniques, the tribological performance and mechanisms of the NBR samples coated with different lubricants were studied under various working conditions. The results showed that the liquid lubricant significantly reduced the coefficient of friction of the NBR at high rotational speeds by over 92.2%. The sample coated with HDI showed obvious tribochemical wear, and coating with the rest of the liquid lubricants decreased the specific wear rate of NBR. According to the friction-induced vibration signals, we found that an increase in loading aggravated friction-induced vibrations, and the vibrational energy was mainly concentrated in the low frequency range. The liquid paraffin and TO coatings barely changed the vibration characteristics of the NBR, while the other three lubricants produced more friction-induced self-oscillations. In conclusion, compared to the other liquid lubricants, TO exhibited the best tribological performance. The finding of this study further our understanding of the friction and vibration behaviours of polymer materials, providing a reliable basis for designing composite materials with good lubrication and vibration damping performance. • A feasible method for friction-induced vibration testing and analyzing is provided. • The tribological behavior database of liquid lubricants is improved. • Tung oil shows excellent lubricating performance. • The lubrication state is revealed by friction, wear and vibration together. [ABSTRACT FROM AUTHOR]

We demonstrate the modulation instability (MI) and four-wave mixing (FWM) spectra at the input of a pump accompanied with a seed in the dispersion-shifted fiber. By numerically solving the nonlinear Schrodinger equation, it is confirmed that there are two regions as the absolute value of the second-order fiber dispersion decreases, where MI and FWM dominates, respectively. We attribute this phenomenon to the competition between MI and FWM. Furthermore, for the FWM-dominating region, it can be divided into two subregions according to the different power levels of MI, which mainly results from the power transfer between MI and dispersive wave. Our results may lead to a further understanding of nonlinear interactions in optical fiber. [ABSTRACT FROM AUTHOR]

The nanopowders of Zn 2 SnO 4 were prepared via a hydrothermal method with different solution pH values. The influence of the pH value on the crystal structure, morphology, specific surface area, and gas sensing performance was comparatively investigated. The sensor prepared at the pH value of 13 showed the most promising integral ethanol gas sensing properties. At the optimal operating temperature of 300 °C, the sensor response increased linearly with ethanol concentration among the range of 5–200 ppm and showed a sensitivity of 0.213/ppm, a response/recovery time less than 15 s, and a high ethanol gas sensing selectivity against to acetone, methylbenzene and methanol. The related sensing mechanism was discussed based on the structural characteristics and the sensing properties. The results indicated that as-prepared Zn 2 SnO 4 nanopowders might be a promising candidate material for fabricating practical ethanol gas sensors. [ABSTRACT FROM AUTHOR]

The interaction between laser and water flow is very complicated in the absorption chamber of a high energy laser (HEL) energy meter which directly uses water as an absorbing medium. Therefore, the heat exchange model cannot be studied through traditional methods, but it is the most important factor to improve heat exchange efficiency in the absorption chamber. After the exchanges of heat and mass were deeply analyzed, experimental study and numerical fitting were brought out. The original testing data of laser power and water flow temperature at one moment were utilized to calculate those at the next moment, and then the calculated temperature curve was compared with the measured one. If the two curves matched well, the corresponding coefficient was obtained. Meanwhile, numerous experiments were performed to study the effects of laser power, duration, focal spot scale, and water flow rate on heat exchange coefficient. In addition, the relationship between water phase change and heat exchange was analyzed. The heat exchange coefficient was increased by optimizing the construction of the absorption chamber or increasing water flow rate. The results provide the reference for design of water-direct-absorption-typed HEL energy meters, as well as for analysis of the interaction between other similar lasers and water flow. [ABSTRACT FROM AUTHOR]

High spatial frequency laser-induced periodic surface structures (high-spatial frequency LIPSSs; HSFLs), being beyond the optical diffraction limit, have attracted great attention due to their outstanding physical characteristics and potential for use in various fields. However, the formation mechanism of HSFL is still controversial, which severely limits their further applications. In this work, a novel numerical model with experimental support are proposed to explain the formation of HSFL through the existence of subsurface plasmon polaritons (Sub-SPPs) generated at the subsurface of the material. According to the results, the period of HSFL is determined by the competition between the propagation loss of Sub-SPP and the penetration loss of fs-laser pulses. Given this competition, the HSFL formation can be investigated through the optical method by introducing a typical dielectric constant and thereby avoiding the discussion of complex electronic behavior. The numerical simulation results are in good agreement with the experimental data acquired on various materials, thus evidencing the applicability of this model. This work provides a clear physical picture of HSFL formation, allowing one to develop state-of-the-art surface morphology controlling methods for potential manufacturing applications. [Display omitted] • Experimental support of sub-surface energy deposition in HSFL formation is obtained. • A novel numerical model is developed to explain HSFL formation. • The stability of HSFL period is analyzed through different types of losses. [ABSTRACT FROM AUTHOR]

In order to meet the needs of phase generated carrier (PGC) demodulation technology for interferometric fiber optic hydrophones, we proposed an optical microfiber all-optical phase modulator (OMAOPM) based on the photo-induced thermal phase shift effect, which can be used as a phase carrier generation component, so as to make the modulation efficiency and working bandwidth of this type of modulator satisfy the requirements of underwater acoustic signal demodulation applications. We analyzed the modulation principle of this modulator and optimized the structural parameters of the optical microfiber (OM) when the waist length and waist diameter of OM are 15 mm and 1.4 μm, respectively. The modulation amplitude of the modulator can reach 1 rad, which can meet the requirements of sensing applications. On this basis, the fiber optical hydrophone PGC-Atan demodulation system was constructed, and the simulated underwater acoustic signal test demodulation research was carried out. Experimental results showed that the system can demodulate underwater acoustic signals below 1 kHz. [ABSTRACT FROM AUTHOR]