Search

Introduction: Incarceration occurred in approximately 5% to 15% of inguinal hernia patients, with around 15% of incarcerated cases progressing to intestinal necrosis, necessitating bowel resection surgery. Patients with intestinal necrosis had significantly higher mortality and complication rates compared to those without necrosis.The primary objective of this study was to design and validate a diagnostic model capable of predicting intestinal necrosis in patients with incarcerated groin hernias. Methods: We screened the clinical records of patients who underwent emergency surgery for incarcerated inguinal hernia between January 1, 2015, and December 31, 2022. To ensure balanced representation, the enrolled patients were randomly divided into a training set (n = 180) and a validation set (n = 76) using a 2:1 ratio. Logistic regression analysis was conducted using the rms package in R software, incorporating selected features from the LASSO regression model, to construct a predictive model. Results: Based on the results of the LASSO regression analysis, a multivariate logistic regression model was developed to establish the predictive model. The predictors included in the model were Abdominal effusion, Hernia Sac Effusion, and Procalcitonin. The area under the receiver operating characteristic (ROC) curve for the nomogram graph in the training set was 0.977 (95% CI = 0.957–0.992). In the validation set, the AUC for the nomogram graph was 0.970. Calibration curve and decision curve analysis (DCA) verified the accuracy and practicability of the nomogram graph in our study. Conclusion: Bowel necrosis in patients with incarcerated inguinal hernia was influenced by multiple factors. The nomogram predictive model constructed in this study could be utilized to predict and differentiate whether incarcerated inguinal hernia patients were at risk of developing bowel necrosis. [ABSTRACT FROM AUTHOR]

There was significant controversy about whether lateral lymph node dissection (LLND) should be performed routinely during radical rectal cancer surgery. This study compared total mesorectal excision (TME) with or without LLND in low and middle rectal cancer. Our team retrieved data from Pubmed, EMBASE, Ovid, Web of Science, and the Cochrane Library from their incipience to Oct 1, 2021. We combined the statistics using the survival variables' hazard ratio (HR). If the article only provided survival curves and delivered no HR value, we used a statistical method to extract logHR and standard errors for data estimation. A total of 33 studies were included in this study (26 cohort studies and 7 randomized controlled trials (RCTs). We found a statistically significant difference in the 5-year postoperative local recurrence rate between LLND + TME group patients (HR = 1.36, 95% CI: 1.07–1.73, p = 0.01); no statistically significant difference in 5-year postoperative overall survival (OS) (HR = 0.95, 95% CI: 0.85–1.06, p = 0.36) and recurrence-free survival (RFS) (HR = 1.13, 95% CI: 0.99–1.29, p = 0.08) between patients in the LLND + TME and TME groups; no statistically significant difference in 5-year OS and RFS between the LLND + TME and TME groups, regardless of preoperative lateral lymph node metastasis (LLNM). LLND + TME was associated with significantly longer operation time (WMD 92.29, 95% CI 82.29–102.28, p < 0.00001), more intraoperative blood loss (WMD 261.31, 95% CI 196.39–326.24, p < 0.00001), higher urinary dysfunction (OR = 2.15, 95% CI 1.16–3.96, P = 0.01), and sexual dysfunction (OR = 6.33, 95% CI 1.73–23.13, P = 0.005). Whereas anastomotic leakage (OR = 1.00, 95% CI 0.54–1.85, p = 0.99) and bowel obstruction (OR = 1.03, 95% CI 0.42–2.54, p = 0.95) were similar between the two groups. LLND did not improve the long-term prognosis of patients with rectal cancer, prolonged the duration of surgery, increased intraoperative bleeding, and led to a higher incidence of postoperative voiding disorders and sexual dysfunction. [ABSTRACT FROM AUTHOR]

Permanent magnet synchronous motor (PMSM) drive systems are commonly utilized in mobile electric drive systems due to their high efficiency, high power density, and low maintenance cost. To reduce the tracking error of the permanent magnet synchronous motor, a reinforcement learning (RL) control algorithm based on double delay deterministic gradient algorithm (TD3) is proposed. The physical modeling of PMSM is carried out in Simulink, and the current controller controlling id-axis and iq-axis in the current loop is replaced by a reinforcement learning controller. The optimal control network parameters were obtained through simulation learning, and DDPG, BP, and LQG algorithms were simulated and compared under the same conditions. In the experiment part, the trained RL network was compiled into C code according to the workflow with the help of rapid prototyping control, and then downloaded to the controller for testing. The measured output signal is consistent with the simulation results, which shows that the algorithm can significantly reduce the tracking error under the variable speed of the motor, making the system have a fast response. [ABSTRACT FROM AUTHOR]

Electronic tattoos have great potential application in the biomedical field; moreover, the substrate-free electronic tattoo offers better comfortability and conformal contact. However, the substrate-free electronic tattoo is more prone to malfunction, including fall off and fracture. In this paper, a self-healing and self-adhesive substate-free tattoo based on PEDOT: PSS is studied and reported. The dry composite electrode will turn into self-healing material while it transforms into hydrogel, and a cut with a width up to 24 μm could be healed in 1 s. In terms of adhesion performance, the substrate-free electrode can hang a 28.2 g weight by a contact area of 8 mm × 8 mm. Additionally, the substate-free electrode could maintain fully conformal contact with porcine skin in 15 days by its self-adhesiveness. When applied as a substrate-free tattoo, the contact impedance and ECG signal measurement performance before and after self-healing are almost the same. At a frequency of 10 Hz, the contact impedance of the undamaged electrode, healed electrode, and Ag/AgCl gel electrode are 32.2 kΩ, 39.2 kΩ, and 62.9 kΩ, respectively. In addition, the ECG signals measured by the undamaged electrode and healed electrode are comparable to that of Ag/AgCl electrode. The self-healing and self-adhesive substrate-free tattoo electrode reported here has broad application in health monitoring. [ABSTRACT FROM AUTHOR]

In this paper, we present difference of convex algorithms for solving bilevel programs in which the upper level objective functions are difference of convex functions, and the lower level programs are fully convex. This nontrivial class of bilevel programs provides a powerful modelling framework for dealing with applications arising from hyperparameter selection in machine learning. Thanks to the full convexity of the lower level program, the value function of the lower level program turns out to be convex and hence the bilevel program can be reformulated as a difference of convex bilevel program. We propose two algorithms for solving the reformulated difference of convex program and show their convergence to stationary points under very mild assumptions. Finally we conduct numerical experiments to a bilevel model of support vector machine classification. [ABSTRACT FROM AUTHOR]

The paper proposes and justifies a new algorithm of the proximal Newton type to solve a broad class of nonsmooth composite convex optimization problems without strong convexity assumptions. Based on advanced notions and techniques of variational analysis, we establish implementable results on the global convergence of the proposed algorithm as well as its local convergence with superlinear and quadratic rates. For certain structured problems, the obtained local convergence conditions do not require the local Lipschitz continuity of the corresponding Hessian mappings that is a crucial assumption used in the literature to ensure a superlinear convergence of other algorithms of the proximal Newton type. The conducted numerical experiments of solving the l 1 regularized logistic regression model illustrate the possibility of applying the proposed algorithm to deal with practically important problems. [ABSTRACT FROM AUTHOR]

Because the road surfaces of the underground roadways in coal mines are slippery, uneven, with dust and water mist, and the noise and light illumination effects are significant, global positioning system (GPS) signals cannot be received, which seriously affects the ability of the odometer, optical camera and ultrasonic camera to collect data. Therefore, the underground positioning of coal mines is a difficult issue that restricts the intellectualization of underground transportation, especially for automatic robots and automatic driving vehicles. Ultra-wide band (UWB) positioning technology has low power consumption, high performance and good positioning effects in non-visual environments. It is widely used in coal mine underground equipment positioning and information transmission. In view of the above problems, this research uses the WLR-5A mining unmanned wheeled chassis experimental platform; uses two UWB receivers to infer the position and yaw information of the vehicle in the underground roadway through the method of differential mapping; and tests the vehicle on the double shift line and quarter turn line in the GAZEBO simulation environment and on the ground simulation roadway to simulate the vehicle meeting conditions and quarter turning conditions in the underground roadway. The positioning ability of the method in these two cases is tested. The simulation and test results show that the vehicle position and attitude information deduced by two UWB receivers through the differential mapping method can basically meet the requirements of underground environments when the vehicle is traveling at low speeds. [ABSTRACT FROM AUTHOR]

The unevenly distributed mechanical properties of welded joints are one of the important factors, which affect welded joints' safety seriously. The user-defined field (USDFLD) subroutine in ABAQUS finite element software can introduce variable-dependent material properties. This method can define inhomogeneous materials whose mechanical parameters depend on spatial coordinates and can be used to characterize the uneven mechanical properties of heat-affected zone and fusion zone. By establishing the static crack finite element model of welded joint with continuous change in yield strength, the sudden change in mechanical field in the numerical simulation process of sandwich structure model is eliminated. Compared with the existing numerical simulation methods of local mechanical heterogeneity of welded joints, this method provides a method to realize the structural integrity evaluation of welded joints. [ABSTRACT FROM AUTHOR]

The explosion-proof diesel engine trackless rubber-tyred vehicle (TRTV) has the disadvantages of high fuel consumption and serious exhaust emissions, while the problems of insufficient power and short endurance limit the development of the explosion-proof battery trackless rubber-tyred vehicle. Hybrid technology can effectively reduce fuel consumption and emissions on the basis of ensuring sufficient power. Exploring the application of hybrid electric trackless rubber-tyred vehicle (HETRTV) has practical significance for coal mine auxiliary transportation. The degree of hybridization (DOH) will directly affect the performance and cost of TRTV, which needs to be focused in the development process. The effects of DOH on dynamic performance, fuel economy, emission performance, and cost were studied based on a simulation by ADVISOR, and the results were verified and analyzed by experiment. Compared with the flameproof diesel engine trackless vehicles, HETRTV with the optimal DOH exhausts has far less gas emissions. The engine fuel consumption and the equivalent fuel consumption of the vehicle are reduced by 33.9% and 12.5%, respectively. The results showed that in spite of a small increase in cost, the HETRTV with the optimal DOH can not only meet the driving requirements of underground working conditions but also greatly improve fuel economy and emission performance. [ABSTRACT FROM AUTHOR]

The dysbiosis of the gut microbiota has been implicated in various maladies. Research has identified an association between the dysbiosis of the gut microbiota and the risk of constipation, prompting this study to elucidate the potential causal relationship between gut microbiota imbalance with constipation through a two sample bidirectional Mendelian randomization (MR) study, shedding light on the genetic mechanisms underlying the connection between gut microbiota and constipation. The forward MR analysis aimed to scrutinize whether alterations in the composition and abundance of gut microbiota impact the risk of constipation, while the reverse MR analysis explored whether the genetic predisposition to constipation influences the abundance of gut microbiota. Genomic correlation data for the gut microbiota were sourced from the comprehensive statistics of the MiBioGen consortium. Genomic correlation data for constipation were obtained from the IEU database, encoded as the dataset ebi-a-GCST90018829. The correlation was assessed using various analytical techniques, including inverse variance weighting (IVW), Mendelian randomization-Egger regression (MR-Egger), and weighted median and mode methodologies. To ensure the robustness of the results, a meticulous sensitivity analysis was conducted, incorporating Cochran's Q test, MR-Egger intercept test, Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO), and a Leave-one-out analysis. In the forward Mendelian randomization analyses, a negative correlation was discerned between the abundance of Coprococcus in the gut microbiota and the occurrence of constipation (IVW: OR = 0.74, 95 % CI = 0.64–0.86, p = 0.0001), whereas a positive correlation was observed between the abundance of Bacteroidetes in the gut microbiota and constipation (IVW: OR = 1.22, 95 % CI = 1.00–1.50, p = 0.04). In the forward Mendelian randomization analyses, we were unsuccessful in obtaining valid instrumental variables for scrutiny, and we deemed that constipation exerts no influence on the composition of the gut microbiota. Genetic predisposition towards increased abundance of Coprococcus and decreased abundance of Bacteroidetes is correlated with a diminished susceptibility to constipation. This investigation showed that alterations in the gut microbiota precipitated the onset of constipation, rather than constipation inducing modifications in the microbial flora. [ABSTRACT FROM AUTHOR]

The mechanical properties of dissimilar metal-welded joint materials are heterogeneous, which is an obstacle to the safety evaluation of key welded structures. The variation of stress–strain conditions at the crack tip caused by mismatch of material mechanical properties in dissimilar metal-welded joints is an important factor affecting crack propagation behavior. To understand the influence of uneven distribution of ultimate strength of the base metal and the welded metal on the crack propagation path, fracture toughness, as well as the mechanical field at the crack tip in the small-scale yield range, the user-defined field variable subroutine method is used to express continuous variation characteristics of welded joint ultimate strength in finite element software. In addition, the J-integral during crack propagation is calculated, and the effect of the ultimate strength on the J-integral and the stress field at the crack tip are analyzed. The results show that as the crack propagation direction is perpendicular to the direction of ultimate strength, the gradient of ultimate strength increases from |Gy|= 50 to |Gy|= 100 MPa/mm, the crack deflection angle increases by 0.018%, and the crack length increases by 1.46%. The fracture toughness of the material decreased slightly during crack propagation. Under the condition that the crack propagation direction is the same as the direction of ultimate strength, the crack propagation path is a straight line. As the gradient of ultimate strength increases from Gx = 50 to Gx = 100 MPa/mm, the crack propagation length decreases by 5.17%, and the slope of fracture toughness curve increases by 51.63%. On the contrary, as the crack propagates to the low ultimate strength side, the crack propagation resistance decreases, the ultimate strength gradient increases from Gx = −100 to Gx = −50 MPa/mm, and the slope of the fracture toughness curve decreases by 51.01%. It is suggested to consider the relationship between crack growth behavior and ultimate strength when designing and evaluating the structural integrity of cracks at the material interface of dissimilar metal-welded joints. [ABSTRACT FROM AUTHOR]

• A new fault diagnosis method for rotating machinery is proposed by integrating an acoustic-vibration fusion framework and a regularization function. • The proposed acoustic-vibration fusion framework explores the feature connections between multi-sensor signals and provides stronger feature representations. Traditional fault diagnosis (FD) for rotating machinery solely based on vibration signals has problems such as inconvenient collection, low accuracy, and poor robustness. This article proposes a fusion framework based on tensor fusion and dual attention network (TFDAN), utilizing acoustic and vibration signals from two datasets of centrifugal pumps and cylindrical roller bearings. Firstly, continuous wavelet transform (CWT) is used to transform two original signals into two-dimensional time–frequency maps to highlight time–frequency features. Then, the images are fed into the fusion framework, where tensor fusion can construct the corresponding time–frequency maps of the working conditions into multi-channel datasets, enhancing the feature connections between acoustic and vibration signals. The dual attention network takes on the fused samples, extracts local features of the image using its positional attention module, and further aggregates feature correlations between channels using its channel attention mechanism. Finally, in order to simulate the actual production situation, different proportions of noisy labels are added to the dataset. In response to the impact of noisy labels, we incorporate an improved contrastive regularization function (ICRF) into the model, fully utilizing its advantage of preventing overfitting of noisy labels. The effectiveness of our proposed method has been demonstrated through two experimental cases. Compared with other methods, our method has better performance in terms of diagnostic accuracy and robustness to noisy labels. [ABSTRACT FROM AUTHOR]

Low-dimensional IIIâ€"V semiconductor arrays have been widely investigated for photonic, electronic and optoelectronic applications. Bottom-up epitaxy of nanostructures with metastable phase is an effective approach to modify their optical and electronic structures. However, in addition to their optical properties, their thermal properties are also important and can affect device performance. Here, we use wurtzite InP nanosheet arrays as an example and perform detailed optical and Raman scattering studies. It is shown that Al2O3 provides good protection for nanosheets up to 873 K without any observable deterioration in optical properties or phase transition. The A 1(TO) and E 2 h modes show opposite trends in polarization-dependent Raman scattering. The first-order temperature coefficient and thermal expansion coefficient of wurtzite and zincblende InP are obtained from temperature-dependent Raman experiments and are quite close to each other. Furthermore, by applying density functional theory and density functional perturbation theory, the GrĂĽneisen parameter and the thermal expansion of wurtzite InP lattice are calculated, showing good agreement with the experimental Raman data. There is little thermodynamic property difference between wurtzite and zincblende InP phase. The revealed thermal properties of the InP nanosheets provide valuable information for those devices that operate at high temperatures. [ABSTRACT FROM AUTHOR]

Electro-hydraulic Stewart 6-DOF platform is a 6-DOF parallel mechanism combined with the electro-hydraulic servo control system, which is widely used in the field of construction machinery. In actual working conditions, the flow and pressure pulsation of the hydraulic oil output from the hydraulic leg of the electro-hydraulic Stewart platform are inevitable, so the equivalent stiffness of the platform leg will change, and the stiffness parameters of the transmission system will change, resulting in vibration, which will affect the accuracy of the platform. This paper considering the fluid unit equivalent stiffness cyclical fluctuations and leg, on the basis of the relationship between hydraulic stiffness, constructs the electric hydraulic Stewart platform machine vibration dynamics equation, fluid coupling parameters of vibration parameters using the method of the multiscale approximate analytic formula of the main resonance and combination resonance are derived, and the system parameters vibration time-domain response and frequency response under two different poses are discussed. Results show that the system first to six order natural frequency and the first to the sixth order natural frequency and frequency of hydraulic oil equivalent stiffness of the combination of frequency will have an effect on the parameters of the system vibration. In the main resonance, the dominant frequency is mainly the first to sixth order natural frequency of the system; in the combined resonance, the dominant frequency is the combined frequency. Through the parameter vibration analysis of two different positions of the platform, it is concluded that when the platform is in an asymmetric position, each leg of the system is more involved in vibration. This study can provide the reference for the subsequent dynamic optimization and reliability analysis of the electro-hydraulic Stewart platform. [ABSTRACT FROM AUTHOR]

Selective area epitaxy (SAE) can be used to grow highly uniform III–V nanostructure arrays in a fully controllable way and is thus of great interest in both basic science and device applications. Here, an overview of this promising technique is presented, focusing on the growth fundamentals, formation of III–V nanowire arrays, monolithic integration of III–V nanowire arrays on silicon, the growth of nanowire heterostructures, and networks of various shapes. The applications of these III–V nanostructure arrays in photonics, electronics, optoelectronics, and quantum science are also reviewed. Finally, the current challenges and opportunities provided by SAE are discussed. [ABSTRACT FROM AUTHOR]

Through self-developed testing technology, in situ liquefaction tests are conducted and dynamic properties of saturated sand are investigated. Testing results indicate that pore pressure-shear strain relationship (PSR) is independent of acceleration and pore pressure generation is relatively uniquely related to the induced shear strain. Based on experimental results, two equations are, respectively, proposed to describe PSR and G/Gmax~ γ of liquefied sand. It reveals that shear strain can fundamentally reflect the process of soil liquefaction and the effect of liquefaction on dynamic characteristics of sand, which provides more solid foundations to develop strain-based analytical method and strategy for soil liquefaction. [ABSTRACT FROM AUTHOR]

• A novel B. cereus phage DZ1, belonging to Andromedavirus geneus, was isolated. • DZ1 lyses 21 different sequence types B. cereus , including emetic strains. • DZ1 can decrease B. cereus contamination on spiked rice and milk effectively. • DZ1 shows the potential to control B. cereus in food industry. Bacillus cereus is a pathogenic bacterium that causes food contamination, resulting in food poisoning such as diarrhea and emesis. Therefore, it is crucial to develop effective strategies to control this bacterium. In this study, we isolated and characterized a novel B. cereus phage, named DZ1. Morphological and genomic analyses revealed that phage DZ1 is a new species belonging to the Andromedavirus genus. Phage DZ1 was tolerant to a wide range of pH values (5–9), temperatures (4–55 ℃), and high concentrations of NaCl solution (1000 mM). B. cereus with 21 different sequence types (STs) can be lysed by phage DZ1. Importantly, phage DZ1 inhibited B. cereus growth in spiked rice substrates or milk up to 36 and 72 h, respectively, with suppression of 3 log. Therefore, phage DZ1 is a useful biocontrol agent for the control of B. cereus in the food industry. [ABSTRACT FROM AUTHOR]

The optimal control of thermally convective flows is usually modeled by an optimization problem with constraints of Boussinesq equations that consist of the Navier-Stokes equation and an advection-diffusion equation. This optimal control problem is challenging from both theoretical analysis and algorithmic design perspectives. For example, the nonlinearity and coupling of fluid flows and energy transports prevent direct applications of gradient type algorithms in practice. In this paper, we propose an efficient numerical method to solve this problem based on the operator splitting and optimization techniques. In particular, we employ the Marchuk-Yanenko method leveraged by the L 2 -projection for the time discretization of the Boussinesq equations so that the Boussinesq equations are decomposed into some easier linear equations without any difficulty in deriving the corresponding adjoint system. Consequently, at each iteration, four easy linear advection-diffusion equations and two degenerated Stokes equations at each time step are needed to be solved for computing a gradient. Then, we apply the Bercovier-Pironneau finite element method for space discretization, and design a BFGS type algorithm for solving the fully discretized optimal control problem. We look into the structure of the problem, and design a meticulous strategy to seek step sizes for the BFGS efficiently. Efficiency of the numerical approach is promisingly validated by the results of some preliminary numerical experiments. [ABSTRACT FROM AUTHOR]

Phages have been approved for use in the food industry to control bacterial contamination in some countries. However, their broader adoption is hindered by some limitations. For instance, the persistence of infectious phages in the food industry can lead to the emergence of resistant bacteria, which negatively impacts the long-term effectiveness of phages. Additionally, the narrow host range of phages limits their effectiveness against various strains. To address these deficiencies, phage engineering has been proposed as a rational approach for modifying phages. In this study, we developed a simple and efficient engineering method for Bacillus cereus phage, using DK1 as an example, to reduce the number of residual phages and expand its range of hosts. Specifically, we knocked out the appendage gene, which codes for the receptor-binding protein, to produce phage progeny with structural defects in their appendages, resulting in the loss of infectivity after host elimination. Furthermore, we used plasmid-mediated means to express different appendage proteins during phage preparation, which allowed altering the host spectrum of the engineered phages without gene insertion. In practical applications, our engineered phages effectively reduced the number of B. cereus in milk and prevented the amplification of active progeny. Our strategy transformed phages from active viruses into more controllable antibacterial agents, making them safer and more efficient for the prevention and control of B. cereus. Moreover, we believe this strategy will help drive the use of engineered phages in the food industry. • Marker-free knockout of housekeeping genes in Bacillus lytic phage was achieved. • Deletion of appendage gene can achieve self-inactivation of Bacillus lytic phage. • Self-inactivated phage maintains high antibacterial ability. • Convenient method to change the phage host was done through a plasmid mediated way. • Self-inactivated phage can be used effectively to kill the target bacteria in milk. [ABSTRACT FROM AUTHOR]

Surface passivation of semiconductor nanowires (NWs) is important for their optoelectronic properties and applications. Here, the in situ passivation effect of an epitaxial InP shell and the corresponding photodetector performance is experimentally studied. Compared with the unpassivated GaAs1–xSbx core-only NWs, the GaAs1–xSbx/InP core/shell NWs have shown much stronger photoluminescence and cathodoluminescence intensities. Correspondingly, the fabricated single GaAs1–xSbx/InP core/shell NW photodetector shows a responsivity of 325.1 A W−1 (@ 1.3 μm and 1.5 V) that is significantly enhanced compared to that of single GaAs1–xSbx core-only NW photodetectors (143.5 A W−1), with a comparable detectivity of 4.7 × 1010 and 5.3 × 1010 cm√Hz/W, respectively. This is ascribed to the enhanced carrier mobility and carrier concentration by the in situ passivation, which lead to both higher photoconductivity and dark-conductivity. Our results show that in situ passivation is an effective approach for performance enhancement of GaAs1–xSbx NW based optoelectronic devices. [ABSTRACT FROM AUTHOR]

Line-commutated converter based high voltage direct current (LCC-HVDC) transmissions are widely applied in delivering large-capacity electricity in China. Multiple large-capacity LCC-HVDC transmissions strengthen dynamic coupling between AC and DC networks. Existing literature has reported some stability problems caused by dynamic interactions between AC and DC power grids, however, the mechanism behind these problems has not been totally understood and revealed. To analyze dynamic interactions between AC and DC power grids, this article presents a small-signal model to understand the external characteristics of LCC-HVDC stations based on the motion equation concept. Comparison of time-domain simulation response with the detailed switching model shows that the proposed model can hold main behaviors of concern. Dynamic interactions between AC and DC power grids are studied based on the proposed model in multi-infeed LCC-HVDC systems. Analytical results demonstrate that there exists power dynamics in receiving AC grid when sending AC grid subjects to a disturbance, and effects of converter stations’ controller parameters on power dynamics are explained by the physical relationship among state variables of the proposed model. [ABSTRACT FROM AUTHOR]

Abstract The lattice misfits of different CeO 2 /NbC interfaces were calculated by Bramfitt two-dimensional lattice misfit degree theory. The interface relationship of CeO 2 (100)/NbC(111) was calculated by first principles, and the possibility of CeO 2 as the heterogeneous nucleus of NbC was analyzed as well. In this paper, hypereutectic Fe-Cr-C hardfacing coating was prepared with NbC and CeO 2 addtion to observe its microstructure by Transmission Electron Microscope (TEM) and optical microscope (OM). The calculated results show that the lattice misfit of CeO 2 (100)/NbC(111) is the smallest (7.85%), which indicates that it is moderately effective for the CeO 2 as the heterogeneous nucleus of NbC. Four interfaces were constructed between CeO 2 and NbC, which are Ce-C, Ce-Nb, O-C, and O-Nb ones. The adhesive works of Ce-C and Ce-Nb interfaces are small, which are negative. And their interface energies are large, which indicates that they are extremely unstable and easy to decompose. The adhesive work of O-Nb interface is the largest, which is positive. Its interface energy is the smallest, so that O-Nb interface is thermodynamically stable. O-C interface is less stable than O-Nb interface. In addition, O-C and O-Nb interfaces contains covalent, metallic and ionic bonds. The experimental results proves that CeO 2 can be as the heterogeneous nucleus of NbC, then refines NbC. Graphical abstract Image 1 Highlights • The misfit of CeO 2 (100)/NbC(111) is moderately effective with 7.85%. • CeO 2 (100) and NbC (111) are polar surfaces with four surfaces. • W a d C e − N b < W a d C e − C < W a d O − C < W a d O − N b , γ O − N b < γ O − C < γ C e − N b < γ C e − C . • CeO 2 exists in NbC that can act as the heterogeneous nucleus of NbC and refine it. [ABSTRACT FROM AUTHOR]

The alternating direction method of multipliers was proposed by Glowinski and Marrocco in 1974, and it has been widely used in a broad spectrum of areas, especially in some sparsity-driven application domains. In 1982, Fortin and Glowinski suggested to enlarge the range of the dual step size for updating the multiplier from 1 to the open interval of zero to the golden ratio, and this strategy immediately accelerates the convergence of alternating direction method of multipliers for most of its applications. Meanwhile, Glowinski raised the question of whether or not the range can be further enlarged to the open interval of zero to 2; this question remains open with nearly no progress in the past decades. In this paper, we answer this question affirmatively for the case where both the functions in the objective function are quadratic. Thus, Glowinski’s open question is partially answered. We further establish the global linear convergence of the alternating direction method of multipliers with this enlarged step size range for the quadratic programming under a tight condition. [ABSTRACT FROM AUTHOR]

The magnetic moments of five different doping configurations of Co, Mn, and Co-Mn codoped ZnO were investigated by using first-principles based on density functional theory (DFT), respectively. The total energy, electronic structure, density of state (DOS), partial density of states (PDOS), spatial spin density distribution and Curie temperature of doping ZnO were also studied and analyzed. The energy calculation results show that Co doped ZnO performance ferromagnetism and antiferromagnetism, Mn doped ZnO exhibits only antiferromagnetism, and the Curie temperature of both Mn and Co doping cannot reach the room temperature, but Co-Mn codoping can obtain a high Curie temperature and better ferromagnetism. The electronic structures illustrate that compact structures show better room temperature ferromagnetism. The DOS and PDOS illustrate the magnetic moment is mainly consisted of exchange interaction between Co and Mn, and there are a little exchange interaction between Mn and O atoms. It can be inferred that Co-Mn codoping is a better dopant than Co and Mn in the field of room temperature ferromagnetic materials. [ABSTRACT FROM AUTHOR]

Graphdiyne–ZnO composite is constructed to investigate field-emission. We hope the tip effect of graphdiyne can be strengthened by doping ZnO. We find that the effective movement of the Fermi level and the dwindling of band gap have contributed to the modification of the electronic structures of this composite significantly with increase in the electric field. The high binding energy indicates that the composite model is very stable. In addition, the ionization energies and work functions decrease linearly with the increasing electric field, which represents an improvement of field-emission properties. It implies that graphdiyne–ZnO composite may become a promising material for field-emission. [ABSTRACT FROM AUTHOR]

Bacteriophages are effective in the prevention and control of bacteria, and many phage products have been permitted and applied in the field. Because bacteriophages are expected to replace other antimicrobial agents like antibiotics, the antibacterial effect of bacteriophage has attracted widespread attention. Recently, the diversified defense systems discovered in the target host have become potential threats to the continued effective application of phages. Therefore, a systematic summary and in-depth illustration of the interaction between phages and bacteria is conducive to the development of this biological control approach. In this review, we introduce different defense systems in bacteria against phages and emphasize newly discovered defense mechanisms in recent years. Additionally, we draw attention to the striking resemblance between defense system genes and antibiotic resistance genes, which raises concerns about the potential transfer of phage defense systems within bacterial populations and its future impact on phage efficacy. Thus, attention should be given to the effects of phage defense genes in practical applications. This article is not exhaustive, but strategies to overcome phage defense systems are also discussed to further promote more efficient use of phages. • Bacteria have a variety of defense systems against phages. • Defense systems in bacteria similar to antibiotic resistant genes are transferable. • Transferable defense systems may threat the effectiveness of phages in application. • The strategies to overcome phage defense systems are discussed. [ABSTRACT FROM AUTHOR]

The islanded scenarios of voltage source converter (VSC) high-voltage DC (HVDC) directly supplying power to islanded loads or connecting to wind farm are becoming popular, in which some new issues are required to be further addressed. While several control strategies have been studied, to the authors’ best knowledge, few have investigated the potential capability of VSC HVDC using the typical phase-locked loop (PLL)-synchronized vector control (PLLSynVC) to address islanded operation issues. To explore the potential capability of the typical PLLSynVC in islanded system, this paper proposes a frequency regulation scheme (FRS), including inertia and primary frequency control, for the PLL-synchronized VSC HVDC based on the motion equation concept. By adding the FRS, the VSC HVDC using the PLLSynVC, similar to a synchronous generator from the view of the phase motion equation, not only can self-maintain the frequency stable in an islanded system, but also naturally avoids the transition of control operation modes without changing the basic control structure. Furthermore, based on the developed phase motion equation, the inertia characteristics of VSC HVDC with the FRS is studied, which synthetically considers the impact of different controllers and PLL, and makes VSC HVDC's manifested inertia clear. The effectiveness of FRS and inertia analysis results is verified by time-domain simulations. [ABSTRACT FROM AUTHOR]

Inhibiting component of therapy with (−)-epigallocatechin-3-gallate (EGCG) is low bioavailability of fresh tea polyphenols that outcome from insecurity under stomach related circumstances, insufficient transcellular transport. As needs are, fucose- carboxymethyl chitosan (FU-CMC) graft EGCG with gold nanoparticles (GNPs) (FU-CMC-EGCG-GNPs) nanocomposites were prepared and managed peritumorally to assess their anticancer action. The physicochemical properties of as-prepared nanocomposite were evaluated by FTIR spectroscopy, UV–visible absorption spectra, XRD, FESEM-EDX and HRTEM-SAD. Additionally, the viability and cell uptake assays revealed that the as-prepared nanocomposite successfully repressed the propagation of gastric tumor cells. In vivo anticancer treatment of FU-CMC-EGCG-GNPs nanocomposites showed more anticancer action contrasted with pure EGCG. Immuno-histological investigations established a superior numeral of apoptotic tissues in the as-prepared FU-CMC-EGCG-GNPs nanocomposites contrasted with pure EGCG. Overall, the as-prepared FU-CMC-EGCG-GNPs nanocomposite affords a proficient medicine delivery stage for chemotherapy. [ABSTRACT FROM AUTHOR]

Recently, the alternating direction method of multipliers (ADMM) has found many efficient applications in various areas; and it has been shown that the convergence is not guaranteed when it is directly extended to the multiple-block case of separable convex minimization problems where there are m ≥ 3 functions without coupled variables in the objective. This fact has given great impetus to investigate various conditions on both the model and the algorithm’s parameter that can ensure the convergence of the direct extension of ADMM (abbreviated as “e-ADMM”). Despite some results under very strong conditions (e.g., at least (m − 1) functions should be strongly convex) that are applicable to the generic case with a general m, some others concentrate on the special case of m = 3 under the relatively milder condition that only one function is assumed to be strongly convex. We focus on extending the convergence analysis from the case of m = 3 to the more general case of m ≥ 3. That is, we show the convergence of e-ADMM for the case of m ≥ 3 with the assumption of only (m − 2) functions being strongly convex; and establish its convergence rates in different scenarios such as the worst-case convergence rates measured by iteration complexity and the globally linear convergence rate under stronger assumptions. Thus the convergence of e-ADMM for the general case of m ≥ 4 is proved; this result seems to be still unknown even though it is intuitive given the known result of the case of m = 3. Even for the special case of m = 3, our convergence results turn out to be more general than the existing results that are derived specifically for the case of m = 3. [ABSTRACT FROM AUTHOR]

Doubly fed induction generator (DFIG)-based wind turbines (WTs) occupy a high penetration in power systems and are being required to emulate inertia response as synchronous generators (SGs). Therefore, it is of value to study the impact of inertia control of DFIG-based WT on electromechanical oscillation damping (EOD) of SG. However, relevant studies that are mainly based on eigenvalue analysis method are not enough and general mechanism study is still lacking. This paper studies the impact rules and mechanism of inertia control parameters (proportional constant and time constant) of WT on EOD of SG with a novel approach. First, linearized model of WT under inertia control is derived based on motion equation concept, which can explicitly describe the external characteristic of WT. From the model, it is clear that the proportional constant determines the inertia characteristic of WT, while time constant has decisive effect on the damping characteristic. Then, by interaction analysis based on motion equation models of both SG and WT, the impact rules and mechanism of inertia control parameters on EOD of SG are explained clearly. Besides, since variable inertia control parameters mean variable inertia and damping coefficients of WT, the impact mechanism can be understood from a general perspective. [ABSTRACT FROM PUBLISHER]

With the high penetration of power electronics based renewable energy generators being integrated into power grids, dynamic stability problems have become unprecedentedly challenging in modern power systems. Thus, an accurate description of equipment features for system dynamics analysis is desperately needed. Double fed induction generator (DFIG) wind turbines (WTs) are an example of this type of equipment with extremely complex characteristics. To analyze the effect of DFIG WT system behavior characteristics on angle and voltage stability issues, a small-signal DFIG WT model based on the internal voltage motion equation in the electromechanical time-scale is proposed. This approach models from the perspective of the equipment's internal voltage vector, and describes equipment features through the relationship between the input/output power and the internal voltage phase/amplitude. Understanding of the DFIG WT's internal voltage phase and amplitude motion is deepened by developing an analogy to a real dynamical system a rotor's rotation and the voltage across a capacitor. With this approach, the mechanism describing the dynamics of the internal voltage phase-amplitude is elaborated by a physical perspective, particularly system voltage amplitude dynamics. The factors influencing the phase-amplitude dynamics were investigated based on this model in a single-machine system. [ABSTRACT FROM PUBLISHER]

Power balance, including active and reactive power, between the system supply and the demand from induction motor loads is a potentially necessary condition for system stable operation. Motion of system states depends on the balancing of active and reactive powers. Therefore, this paper proposes an induction machine model in electromechanical timescale from a power balancing viewpoint, in which the induction motor load is modeled as a voltage vector driven by power balancing between the system supply and the demand from induction motor load, so as to describe the dynamic characteristics of induction motor loads in a physical way for power system dynamic analysis. Then a voltage magnitude-phase dynamic analysis with the proposed induction machine model is constructed. Based on the voltage magnitude-phase dynamic analysis, the characteristics of grid-connected induction motor loads are explored, and the instability mechanisms of grid-connected induction motor loads induced by a large disturbance are discussed. It is shown that the dynamic behavior of grid-connected induction motor loads can be described as the dynamic process of the terminal voltage vector driven by coupled active and reactive power balancing in different timescales. In this way, the dynamic behavior of induction motor loads in terms of voltage magnitude-phase dynamics and its physical characteristics are clearly illustrated. Time-domain simulation results are presented to validate the above analyses. [ABSTRACT FROM AUTHOR]

High-frequency oscillations caused by voltage source converters (VSCs) are constantly emerging in power systems with the increasing penetration of renewable energies. VSC models in current control timescale play a pivotal role in the analysis of these oscillation issues. Conventional VSC models show few physical mechanisms of VSC dynamics during system oscillations. Hence, this paper proposes a VSC model from the viewpoint of its internal voltage (namely, VSC output voltage), which is driven by current balancing between the current reference and the feedback in a stationary frame. The proposed model can be used to study VSC dynamic characteristics in an intuitionistic physical way. Based on the proposed model, it is found that VSC current reference in a stationary frame varies with internal voltage dynamic due to the essence of active and reactive current control in a current control timescale. Additionally, in a stationary frame, the dynamic relation between internal voltage and error current embodies a generalized integrating characteristic with adaptable center frequency determined by a phase-locked loop, which guarantees the zero steady state error of VSC current control. Comparisons of simulations between the proposed model and a switch-based model validates the effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

Insulin-like growth factor I (IGF-I) and binding protein 3 (IGFBP-3) play a role in the maintenance of gut mucosal barrier function. Nevertheless, IGF-I/IGFBP-3 and tight junction protein (TJP) expression in small intestinal mucosa are often impaired during endotoxemia. In this model of acute endotoxemia, the regulatory effect of berberine on IGF-I/IGFBP-3 and TJP expression in ileal mucosa was evaluated. The findings revealed systemic injection of lipopolysaccharide (LPS) suppressed mRNA and protein expression of IGF-I and IGFBP-3, but berberine ameliorated their production. LPS injection inhibited occludin and claudin-1 protein generation, and this inhibitory effect of LPS was abolished by berberine. Inhibition of IGF-I/IGFBP-3 signaling by AG1024 or siRNAs reduced berberine-induced occludin and claudin-1 production. Additionally, GW9662 was found to repress berberine-induced IGF-I/IGFBP-3 expression, indicating of a cross-link between PPARγ and IGF-I/IGFBP-3 axis. [ABSTRACT FROM AUTHOR]

The first-swing stability of synchronous generators (SGs) has a close relationship with synchronizing ability of the grid and inertia characteristic of all the generators. This paper studies inertia characteristic of doubly fed induction generator (DFIG) based wind turbine (WT) under transient control to analyze its impact on the first-swing stability of SGs. First, an analytic model of DFIG-based WT following the concept of motion equation is developed to describe and explain its inertia characteristic. The foundation is the definition of internal voltage of DFIG. Based on the model, an important conclusion is drawn that DFIG-based WT under transient control during grid fault has adjustable inertia characteristic that has a clear link with control parameters. Then, the impacts of transient control parameter of DFIG-based WT on the first-swing stability of SGs are studied through numerical simulation. Finally, the impact mechanism of transient control of DFIG-based WT on the first-swing stability of SGs is clearly explained by physical concept of inertia characteristic and synchronizing force. [ABSTRACT FROM AUTHOR]

Periodic arrangement of twin planes creates a controllable polytype that can affect both the electronic and optical properties of nanowires. The approach that is most used for inducing twinning superlattice (TSL) formation in III-V nanowires is introducing impurity dopants during growth. Here, we demonstrate that controlling the growth parameters is sufficient to produce regular twinning planes in Au-catalysed InSb and InP nanowires. Our results show that TSL formation in InSb nanowires only exists in a very narrow growth window. We suggest that growth conditions induce a high concentration of In (or Sb) in the Au droplet, which plays a similar role to that of surfactant impurities such as Zn, and increases the droplet wetting angle to yield a geometry that is favorable for TSL formation. The demonstration of TSL structure in InSb and InP nanowires by controlling the input of In (or Sb) further enhances fundamental understanding of TSL formation in III-V nanowires and allows us to tune the properties of these nanowires by crystal phase engineering. [ABSTRACT FROM AUTHOR]

A thermodynamic reassessment of the ternary C-Ni-Si system is performed by means of calculation of phase diagrams method based on the critical literature review. The fcc_A1/NiSi_L1 disordered/ordered transition is described using a four-sublattice model. Thermodynamic description of the liquid phase is optimized, successfully avoiding the formation of inverted miscibility gap at high temperatures. An optimal and self-consistent set of thermodynamic parameters for the C-Ni-Si system is obtained. The computed phase diagram and phase relations fit well with all the reliable experimental information according to the present modelling. [ABSTRACT FROM AUTHOR]

With the increasing use of voltage source converters (VSCs) in power electronics dominated power systems, oscillation phenomena in DC-link voltage control (DVC) timescale (around 10 Hz) among multiple VSCs have occurred. Several studies have tried to analyze these oscillation problems, but all associated with the single VSC situation. To consider the dynamic interactions between VSCs in DVC timescale, especially in the weak grid condition, this paper presents a small-signal model to understand VSC external characteristics based on motion equation concept also featured in synchronous generator (SG). Comparisons of time-domain simulation responses and eigenvalues show that the proposed model can hold the main behaviors of concern. The form of the model is very similar to the rotor motion equation in SG, with which power engineers have been very familiar. In addition, by establishing the relationship between the unbalanced powers and state variables of internal voltage (viz., VSC output voltage), the modeling idea introduced in this paper can be applied to other power electronic devices. [ABSTRACT FROM PUBLISHER]

To meet the objective requirements of civil engineering construction and mitigation of earthquake disasters, and achieve the goal of economic rationality, we propose a new method for liquefaction-induced lateral spread zonation that is adapted to regionalization and modern technology. To overcome the disadvantage of the National Earthquake Hazard Reduction Program (NEHRP) method that depends on high-density boreholes to complete zoning work, two key technologies of the new method are proposed in this paper, including liquefaction lateral spread level (LLSL) criteria and an extraction technique of polygon features to match the LLSL criteria, detailed as follows. (1) LLSL criteria are used to directly determine the lateral spread level within a certain range of each influence factor. (2) The extraction of polygon features for the influence factors. The geologic and soil condition factors are extracted by combining 3-D geographic information systems and a mining visualization system with geologic interpretation and fewer boreholes. The proposed method is used for the liquefaction-induced lateral spread distribution of a 7.8-magnitude earthquake south of Tangshan, China in 1976. The result is consistent with measurements just after that earthquake. This proves that the new method for liquefaction-induced lateral spread zonation is basically reasonable and feasible. The disadvantage of the NEHRP method, which depends on high-density boreholes, is thereby overcome. This can effectively cut economic costs and still keep the necessary accuracy in the sense of regionalization. [ABSTRACT FROM AUTHOR]

In this work, the adhesion energy, interfacial energy, electronic structure and bonding of WC/LaAlO 3 interface were investigated by first-principles method. Meanwhile, the stable interface structure for LaAlO 3 as the heterogeneous nucleus of WC was also analyzed. The results show that LaAlO 3 (111) slab and WC (0001) slab can reach bulk-like characteristics when the atomic layers N ≥ 9 and N ≥ 7, respectively. For LaAlO 3 (111) surface, in the whole range of Δμ Al , the LaO 3 -terminated structure is more stable than the Al-terminated one. For WC (0001) surface, the W-terminated structure is more stable than the C-terminated one. For the four LaAlO 3 /WC interfaces, the LaO 3 -W-terminated interface exhibits the largest W ad , which is 2.42 J/m 2 . The LaO 3 -C-terminated interface follows, which is 1.26 J/m 2 . Both of them are larger than those of the Al-terminated interfaces. In the whole range of Δμ Al and Δμ C , the interfacial energy of the four LaAlO 3 /WC interfaces exhibits the following sequence: LaO 3 -W interface < LaO 3 -C interface < Al-W interface < Al-C interface. Especially, the interfacial energy of LaO 3 -W-terminated interface is much lower than the other ones, which suggests the much higher stability of the LaO 3 -W-terminated interface. Compared to other LaAlO 3 /WC interfaces, LaAlO 3 is more likely to be the heterogeneous nucleus of WC. The bonding of the LaO 3 -W-terminated interface is a combination of polar covalent bond and metallic bond, and that of the LaO 3 -C-terminated interface is covalent and ionic. Both of them exhibit stronger binding strength than the Al-terminated interfaces. [ABSTRACT FROM AUTHOR]

A thermodynamic reassessment of the ternary Ni–Si–Ti system was performed by means of CALPHAD (CALculation of PHAse Diagram) method. The fcc_A1/Ni 3 Si-L1 2 disordered/ordered transition was described using a four-sublattice model. The enthalpies of formation of the ternary compounds τ 1 , τ 2 , and τ 4 and end-members of the Ti 5 Si 3 and Ni 3 Ti phases at 0 K in the Ni–Si–Ti ternary system were computed via first-principles calculations to supply necessary thermodynamic data for the CALPHAD modeling. In the Ni–Si–Ti ternary system, it was clarified that the ordered Ni 3 Si-L1 2 phase is formed from the liquid phase with the addition of Ti. An optimal set of thermodynamic parameters for the Ni–Si–Ti system was obtained by taking into consideration of the experimental data from the literature and theoretic values from the present first-principles calculations. Comparisons between the calculated and measured phase diagrams indicated that almost all the reliable experimental information was satisfactorily accounted for by the present modeling. [ABSTRACT FROM AUTHOR]

This paper presents an alternative inertial control method for doubly fed induction generator (DFIG)-based wind turbines by directly adjusting the phase locked loop (PLL) response. The synthetic internal voltage vector of the wind turbine-driven DFIG is defined in the electromechanical timescale to present the dynamic properties. The phase angle motion equation is further deduced to depict the relationship between the contributed inertial response and the defined internal voltage. Based on the developed motion equation, the equivalent inertia is estimated and quantified, and further found to be significantly determined by the PLL parameters. Moreover, the effect of both PLL and active power control on the defined internal voltage dynamics is also described during the inertial response. Simulated results on a modified 3-machine, 9-node test system were conducted to validate the feasibility of the proposed inertial control method and the correctness of the developed inertial characteristics. [ABSTRACT FROM AUTHOR]

Voltage problems are challenging in modern power systems with a high penetration of renewables integrated via power electronics. This paper extends the transient time-scale classification to identify voltage dynamics in modern power systems. Voltage dynamics in the current control time-scale is firstly proposed and then the mechanism of terminal voltage change is elaborated. After that the significant influences of the voltage source converter (VSC), current control (CC) loop and voltage feed forward (VFF) on the voltage dynamics in the current control time-scale are discussed. The VSC current control loop provides positive damping on the terminal voltage, while the VFF scheme results in an additional loop that deteriorates terminal voltage dynamic performance and stability. In addition, a sensitivity analysis was carried out to investigate the influence of critical parameters on stability. Finally, simulation results of a current-controlled VSC attached to different strength of AC grids (including a weak grid) are presented to validate the phenomenon and the influencing factors of voltage dynamics in the current control time-scale. [ABSTRACT FROM PUBLISHER]

Developments of wireless body area networks (WBANs) facilitate the pervasive health monitoring with mHealth applications. WBANs can support continuous health monitoring for the human body in convenience and high efficiency without any intervention. The monitoring data in health care have the characteristics of various data flows and heterogeneous data arrival rates, the transmission of which must be in timeliness and reliability, especially the burst data. Moreover, the energy-constraint nodes should be provident in energy consumption. Designing MAC protocols with high reliability and energy efficiency for WBANs is the prime consideration. In this paper, we propose a token-based two-round reservation MAC (TTR MAC) protocol based on IEEE 802.15.6 with considering the data features of health monitoring. With analyzing the characteristics of monitoring data, one-round reservation is conducted for periodic data and two-round reservation is generated adaptively for burst data to save energy. Besides, TTR MAC protocol assigns appropriate number of allocation slots to nodes in heterogeneous data arrival rates. Furthermore, a token is introduced on the basis of user priority and health severity index to indicate the transmission order of nodes with burst data, which highly decreases the average delay. In addition, a bit sequence scheduled algorithm is proposed for m-periodic ( m>1) monitoring data for network capacity expansion. The simulation results show that TTR MAC protocol achieves higher energy efficiency and longer lifetime compared with IEEE 802.15.6 and other one-round reservation MAC (OR MAC) protocols for both 1-periodic and m-periodic data. [ABSTRACT FROM AUTHOR]

This note provides a simple proof of a worst-case convergence rate measured by the iteration complexity for the Douglas-Rachford operator splitting method for finding a root of the sum of two maximal monotone set-valued operators. The accuracy of an iterate to the solution set is measured by the residual of a characterization of the original problem, which is different from conventional measures such as the distance to the solution set. [ABSTRACT FROM AUTHOR]

Mid-infrared GaAs1− xSb x/InP core/shell nanowires are grown coherently with perfectly twin-free zinc blende crystal structure. An unusual triangular InP shell with predominantly {112}A facets instead of {112}B facets is reported. It is found that this polarity preference is due to the surfactant role of Sb, which inhibits InP shell growth rate in the 〈112〉A directions. This behavior reveals a new degree of control and tunability allowed in manipulating nanowire facet geometry and polarity in radial heterostructures by a simple means. Tuning the Sb composition in the core yields controllable intense photoluminescence emission in both the 1.3 and 1.5 μm optical telecommunication windows, up to room temperature for single nanowires. The internal quantum efficiency of the core/shell nanowires is experimentally determined to be as high as 56% at room temperature. Transient Rayleigh scattering analysis brings complementary information, revealing the photoexcited carrier lifetime in the core/shell nanowire to be ≈100 ps at 300 K and ≈800 ps at 10 K. In comparison, the carrier lifetime of core-only nanowire is below the detection limit of the system (25 ps). The demonstrated superior optical quality of the core/shell nanowires and their ideal emission wavelength range makes them highly relevant candidates for near-infrared optoelectronic applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new N, O co-doped graphene was fabricated via facile UV laser engraving. • The graphene electrode has superior sensitivity and stability for nitrite detection. • pH dependance was found and the mechanism behind that was elucidated. Increasing food safety awareness in our daily life has called for the establishment of rapid toxic nitrite detection techniques. In this work, we reported on a facile, quick laser processing method for the preparation of N, O co-doped porous graphene, which was patterned using a computer-controlled system to directly engrave a commercial polyimide (PI) tape, and subsequently used as an electrode for electrochemical nitrite detection. The laser-induced graphene (LIG) was characterized using various physical methods, and the electrochemical performance of the LIG sensing electrode was investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CA). The designed electrode exhibited outstanding sensing ability toward nitrite oxidation. The peak current of the DPV curve had a good linear relationship with analyte concentrations ranging from 5 to 450 μmol/L, and the limit of detection (LOD) was calculated to be 0.8 μmol/L (S/N = 3). None of the common cations and anions yielded a positive current response, demonstrating that the electrode showed superior selectivity for electrochemical nitrite recognition. Furthermore, we observed and elucidated the pH dependence of electrocatalytic activity, which was attributed to the synergy of the surface functional groups derived from N, O co -doped graphene. Owing to its fast response and anti-interference capacity, this new LIG electrode offers great potential as a nitrite electrochemical sensor for environmental applications. [ABSTRACT FROM AUTHOR]

Bacillus cereus is a common foodborne pathogen that causes vomiting and diarrheal symptoms. Due to its spore-forming ability, B. cereus can resist physical sterilization and possess a relatively high contamination level in dairy products; therefore, it is necessary to develop an efficient strategy to control the growth of B. cereus. In this study, a novel bacteriophage, named DLn1, was isolated and characterized, and its endolysin was expressed. Morphological and genomic analyses revealed that the phage is a new species belonging to the Northropvirinae subfamily of the Salasmaviridae family. The life cycle and stability assays showed that the phage DLn1 exhibited a short latent period (15 min) and high burst size (618 plaque-forming units (PFU)/cell) and was tolerant to a wide range of pH (4–10) and temperature (4–55 °C) conditions. This lytic phage had narrow but specific host range to B. cereus strains, and could effectively reduce the number of B. cereus in milk within 6 h. More interestingly, the purified endolysin of phage DLn1 had a much wider lytic range and the inhibitory effect against B. cereus in milk was more efficient. Taken together, the new phage DLn1 and its endolysin could be promising biocontrol agents against B. cereus in dairy products. • A new lytic phage infecting B. cereus , named DLn1, was identified from sewage. • The endolysin of phage DLn1 was expressed and purified. • The endolysin of phage DLn1 had wider lytic range than its parental phage. • DLn1 and its endolysin have potentials to control the contamination of B. cereus in milk. [ABSTRACT FROM AUTHOR]

Euclidean distance embedding appears in many high-profile applications including wireless sensor network localization, where not all pairwise distances among sensors are known or accurate. The classical Multi-Dimensional Scaling (cMDS) generally works well when the partial or contaminated Euclidean Distance Matrix (EDM) is close to the true EDM, but otherwise performs poorly. A natural step preceding cMDS would be to calculate the nearest EDM to the known matrix. A crucial condition on the desired nearest EDM is for it to have a low embedding dimension and this makes the problem nonconvex. There exists a large body of publications that deal with this problem. Some try to solve the problem directly and some are the type of convex relaxations of it. In this paper, we propose a numerical method that aims to solve this problem directly. Our method is strongly motivated by the majorized penalty method of Gao and Sun for low-rank positive semi-definite matrix optimization problems. The basic geometric object in our study is the set of EDMs having a low embedding dimension. We establish a zero duality gap result between the problem and its Lagrangian dual problem, which also motivates the majorization approach adopted. Numerical results show that the method works well for the Euclidean embedding of Network coordinate systems and for a class of problems in large scale sensor network localization and molecular conformation. [ABSTRACT FROM AUTHOR]

The theory of elastic wave scattering is a fundamental concept in the study of elastic dynamics and wave motion, and the wave function expansion technique has been widely used in many subjects. To supply the essential tools for solving wave scattering problems induced by an eccentric source or multi-sources as well as multi-scatters, a whole-space transform formula of cylindrical wave functions is presented and its applicability to some simple cases is demonstrated in this study. The transforms of wave functions in cylindrical coordinates can be classified into two basic types: interior transform and exterior transform, and the existing Graf's addition theorem is only suitable for the former. By performing a new replacement between the two coordinates, the exterior transform formula is first deduced. It is then combined with Graf's addition theorem to establish a whole-space transform formula. By using the whole-space transform formula, the scattering solutions by the sources outside and inside a cylindrical cavity are constructed as examples of its application. The effectiveness and advantages of the whole-space transform formula is illustrated by comparison with the approximate model based on a large cycle method. The whole-space transform formula presented herein can be used to perform the transform between two different cylindrical coordinates in the whole space. In addition, its concept and principle are universal and can be further extended to establish the coordinate transform formula of wave functions in other coordinate systems. [ABSTRACT FROM AUTHOR]