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As photonic integration continues to evolve, compact and low loss Mach–Zehnder interferometers (MZI) have been an area of significant research in recent years. Here, we propose a valley-Hall effect based topologically protected Mach–Zehnder interferometer (TPMZI). Our simulations show that the TPMZI is efficient and stable even in complex situations. Sharp waveguide bending and defects such as obstructions and epitaxial disorders, do not affect the propagation of photons along the interface, which guarantees the TPMZI high output power. In addition, the TPMZI yields excellent sensitivity, extinction ratio and modulation depths, making it advantageous over existing systems when applied to optical communication, biochemical sensing, spectrometer analysis and measurement systems, etc.

As we all know, the large number of counts is a challenging and time consuming task subject because of oversized number and complex conditions. However, the development of deep learning makes deep learning models very competitive in image segmentation. In this paper, we take cigarette filter rods as the research object. we first evaluate the standard Unet for the filter rod target recognition to separate target and background. Secondly, we use the focal loss function instead of the traditional cross-entropy function to solve the problem of imbalance between target and background area. Thirdly, we add a self-attention module in the traditional Unet convolutional layer to enhance the convolution effect. Fourth, we propose structural element detection criteria and round tangency matching strategy based on HMM (Hidden Markov Model) for the geometric relationship of filter rod position, which further improves the accuracy of the algorithm. We used Qu's [1], Mask-R-CNN [2], FCN [3], Deep-lab-V1 [4] and this paper’s algorithm to test the performance of 30000 images from the industrial site. The performance of this paper’s algorithm is completely better than the performance of the above algorithm.

Here, novel and stable core–shell silver–carbon nanocomposites (Ag@CSs) were obtained using glucose as the carbon source and stabilizer, silver nitrate as the silver source, and trioctylamine (TOA) as the soft template and extractant. It is worth mentioning that the shape of the silver core shows the hexagon shape, and we consider that TOA and glucose selectively adsorb the Ag (111) crystal face resulting in this growth pattern of the silver core. Owing to the enhanced local field effect around their sharp corners and edges, such structure exhibits superior properties for the surface-enhanced Raman scattering (SERS) enhancement. The hydrothermal carbon shell not only effectively avoids the agglomeration of Ag nanoparticles core, but also serves as a protective layer of the SERS active nanostructure during the whole course of the experiment. In addition, the thickness of the loose shell was significantly reduced after the product was stored in ethanol solution for a period of time. It is found that dropped cast probe molecules onto Ag@CSs have a lower SERS activity, while that immersed in the probe molecular solution for a period of time have a higher SERS activity, indicating that the detection of the probe molecules using this Ag@CSs substrate may require an interactive process. The results show that the as-obtained Ag@CSs hold tremendous potential for SERS applications for its long-term stability and superior SERS performance.

Characterized by low temperature difference and high heat flux, pool boiling heat transfer has been widely applied in various engineering technical fields. The aim of this study was to explore the thermal performance of pool boiling heat transfer on an enhanced surface modified by the combination of microstructures and wetting properties. The two-dimensional transient volume of fluid model and numerical simulation were selected to investigate each case which was established. Variation of the vapor bubble behavior, the velocity field of computational domain, the temperature at the liquid/solid interface and heat transfer coefficient (HTC) of each case were analyzed. The heat transfer performances of mixed hydrophilic and hydrophobic microstructures were all superior to those of hydrophilic microstructures only, except the flat. With respect to hydrophilic microstructures, the average growth rates of HTC for mixed hydrophilic and hydrophobic microstructures were 17.59%, 21.59%, 2.74% and 3.81% when the heights of microstructures were 3 μ m , 5 7, 7 μ m and 9 μ m , respectively. Moreover, the average growth rate of HTC for mixed hydrophilic and hydrophobic microstructures decreased by 12.44%, 5.31% and 5.21% with increasing width.

At present, the product testing on high-speed assembly line mainly depends on manual testing. Automatic Depression cigarettes detection system is a machine vision method instead of manual testing. The utility model can overcome the defects of easy inspection, high false detection and slow speed of human inspection, and meets the development trend of industrial automation production and the continuous improvement of people's requirements on the quality of cigarettes. In order to quickly and accurately detect complex detonation beads with background texture and improve the computational complexity of traditional algorithms, this paper proposes a dictionary learning algorithm based on sparse representation of cigarettes detonation to indirectly detect the light spots in the image by reducing the dimensionality At the same time, the probability of flare distribution in the shot bead can be calculated by using the algorithm of Markov-Bayesian inference, which can be effectively used in the shot detection. In this experiment, a high-performance industrial computer and a self-developed bursting ball detection algorithm were used to detect the explosive beads on the assembly line, so that the bursting of the added cigarettes could be quickly and accurately detected.

As a new kind of highly compact and efficient micro-channel heat exchanger, printed circuit heat exchanger (PCHE) is a promising candidate satisfying the heat exchange requirements of liquefied natural gas (LNG) vaporization at low and high pressure. The effects of airfoil fin arrangement on heat transfer an flow resistance were numerically investigated using supercritical liquefied natural gas (LNG) as a working fluid. The thermal properties of supercritical LNG were tested by utilizing a REFPROF software database. Numerical simulation was performed using FLUENT. The inlet temperature of supercritical LNG was 121 K,and its pressure was 10.5MPa. The reference mass flow rate of LNG was set 1.22 g/s for the vertical pitch Lv = 1.67 mm and the staggered pitch Ls = 0 mm, with the Reynolds number of about 3750. The SST k-ω model with enhanced wall treatment was selected by comparing with the experimental data. The airfoil fin PCHE had better thermal-hydraulic performance than that of the straight channel PCHE. Moreover, the airfoil fins with staggered arrangement displayed better thermal performance than that of the fins with parallel arrangement. The thermal-hydraulic performance of airfoil fin PCHE was improved with increasing Ls and Lv. Moreover, Lv affected on the Nusselt number and pressure drop of airfoil fin PCHE more obviously. In conclusion, a sparser staggered arrangement of fins showed a better thermal-hydraulic performance in airfoil fin PCHE.

As a new kind of highly compact and efficient micro-channel heat exchanger, the printed circuit heat exchanger (PCHE) is a promising candidate satisfying the heat exchange requirements of liquefied natural gas (LNG) vaporization at low and high pressure. The effects of airfoil fin arrangement on heat transfer and flow resistance were numerically investigated using supercritical liquefied natural gas (LNG) as working fluid. The thermal properties of supercritical LNG were tested by utilizing the REFPROF software database. Numerical simulations were performed using FLUENT. The inlet temperature of supercritical LNG was 121 K, and its pressure was 10.5 MPa. The reference mass flow rate of LNG was set as 1.22 g/s for the vertical pitch Lv = 1.67 mm and the staggered pitch Ls = 0 mm, with the Reynolds number of about 3750. The SST k-ω model was selected and verified by comparing with the experimental data using supercritical liquid nitrogen as cold fluid. The airfoil fin PCHE had better thermal-hydraulic performance than that of the straight channel PCHE. Moreover, the airfoil fins with staggered arrangement displayed better thermal performance than that of the fins with parallel arrangement. The thermal-hydraulic performance of airfoil fin PCHE was improved with increasing Ls and Lv. Moreover, Lv affected the Nusselt number and pressure drop of airfoil fin PCHE more obviously. In conclusion, a sparser staggered arrangement of fins showed a better thermal-hydraulic performance in airfoil fin PCHE.

Novel and stable carbon based embedded silver nano composite materials (Ag/CSs) were successfully prepared by a facile one-pot hydrothermal method with trioctylamine (TOA) as soft template and stabilizer. These as-prepared Ag/CSs exhibit well-defined shape and relatively uniform size with an average diameter of 1.5 μm and uniformly embedded Ag nanoparticles about 5 nm. The proper proportion of glucose, AgNO3 and TOA is the key to the common growth of hydrothermal carbon materials and silver nanoparticles in an embedded way. Besides, the thickness of carbon sphere matrix and the size of Ag particles can be tailored precisely by adjusting the experimental parameters. In order to facilitate comparative analysis, carbon spheres (CSs) without Ag particles embedded were also prepared with glucose under the same hydrothermal reaction conditions. The composition, structure and morphology of the as-prepared Ag/CSs and CSs were confirmed by X-ray powder diffraction (XRD), FT-IR spectroscopy, Raman spectrum, Transmission electron microscopy (TEM) and scanning electron microscopy (SEM). In addition, the possible formation mechanism of the Ag/CSs has been proposed based on experimental evidences. Finally, the as-prepared Ag/CSs and CSs were used as catalysts in the experiments of photocatalytic degradation of methylene MB in water under visible light irradiation and the high efficiency of photocatalytic performance of Ag/CSs has been verified.

According to the physical and traffic flow characteristics of ring road expressways, the road section elements classification and numbering have been conducted, and three types of traffic organization such as diversion, evacuation and rescue under emergency situation have been studied. Taking the road section between Hongqitai Bridge and Beiliguan Bridge of Shenyang third ring road expressway as an example, the specific diversion, evacuation and rescue routes have been proposed.

Emergency traffic organization under the circumstances of incidents is a very important technical aspect in incident management. It accelerates the speed of the highway administration department responding to a critical situation. It requires a good understanding of highway topology and incident situations. A good choice of traffic organization could result in saving many peoples’ lives. In this paper, methods of emergency traffic organization under the circumstances of incidents are studied. The demonstration includes the dividing of emergency responding areas and incident areas. The combine traffic organization for the Up-flow area and incident area in the case of completely interrupted flow or incompletely interrupted flow is described. In the end, Boshen Highway is used as an example to demonstrate how to apply these methods in the real practice.