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Target-tracking applications are promising and possess great theoretical and practical significance, though the research faces great challenges. With the development of multi-modal depth-sensing technology, a large number of scholars have proposed various target-tracking methods based on heterogeneous sensing and demonstrated great results. This review provides an overview of the techniques involved in target tracking in the different layers of the network as well as a comprehensive analysis of the research progress in heterogeneous sensing techniques in each layer. First, this review introduces the single sensing scheme and heterogeneous sensing scheme in the physical layer. Second, we present the heterogeneous communication technologies and heterogeneous optimization methods for communication protocols in the network layer. Third, we combine several typical heterogeneous-sensor target-tracking applications and analyze the applications of cloud computing, edge computing, big data and blockchain technologies. Finally, we discuss the challenges and future direction of heterogeneous-sensor target-tracking methods.

Intelligent urban governance is an inevitable choice to conform to the development trend of modern science and technology. With the development of digitalization, intelligent cities based on artificial intelligence will accelerate the modernization of urban governance. Based on the connotation and basic of intelligent city, this paper analyzes the application of artificial intelligence in the governance of intelligent city. It puts forward the idea that artificial intelligence will promote intelligent city governance, and holds that intelligent government affairs, intelligent transportation, intelligent medical care and intelligent education will greatly improve the efficiency of resource allocation, so as to realize the modernization of urban governance.

In order to read and write the motor controller parameters, download the motor controller program and make the upper computer interface display the running state of the new energy vehicle drive system. This paper designs a serial communication host computer software using Modbus communication protocol and Ymodem communication protocol. The CAN bus interface is provided by the motor controller. The PC is connected to the CAN bus interface of the controller through USB to realize the communication hardware connection between the upper computer and the lower computer. MFC development framework and C + + programming language are used to complete the development of the upper computer software in Visual Studio 2015. Through the analysis of CAN Bus Analyzer and motor test bench, it shows that the upper computer software runs stably and can correctly read the motor controller parameters and send data to it. The design meets the expected requirements.

The dry dual clutch of a passenger car is taken as the research object, and its three-dimensional model is established by software CATIA. On this basis, the thermal load characteristics of the dry dual clutch under the condition of multiple starting on the ramp are analyzed by software ABAQUS. The analysis results show that the temperature rise and thermal stress of the parts caused by the friction heat are within the normal range, which indicates that the designs of the pressure plate and the intermediate driving plate meet the requirements. This study obtains the distributions of the transient temperature field of the clutch friction pair under the conditions of the multiple starting, which has an important reference value for the design and optimization of the dry dual clutch.

RiSE and LEMUR IIB have good climbing ability. Inspired by these two robots, a new climbing robot with simplified motion mode and strong load capacity is proposed. In this paper, the structure of the robot is introduced detailedly. Through the dynamic analysis of its leg and body, the torque of the traction and swing motor under various driving modes are obtained. Static analysis of the robot’s claw is also carried out during the climbing process. Meanwhile, the equivalent tangential force and normal force required for the claw attached to the wall are described. The results indicate that the robot has high mobility and can successfully realize the climbing movement.

Although the agricultural e-commerce platform is developing continuously, it still has the disadvantage of weak mobility, and agricultural products have certain regional and timeliness. Through the application of mobile Internet technology, the design of rural e-commerce operation system is completed. Analyze the important development modes of mobile applications, complete the selection of cross platform development mode, realize the compatibility of multiple mobile systems based on Cordova development framework, give full consideration to the unique attributes of agricultural products, and better meet the needs of agricultural product e-commerce development.

Economic globalization and the rise of e-commerce make the scale of modern logistics company’s cargo transportation more and more large. In this context, the service quality of logistics enterprises often depends on the future of logistics enterprises. Through the establishment of a scientific logistics management system, comprehensive integration of logistics management information, optimization of its process, and ultimately achieve the purpose of improving the efficiency of logistics management business, reducing operating costs, and enhancing the competitiveness of enterprises.

As a sunrise industry in the development of modern agriculture, the development of fresh agricultural products industry has a huge space. Because of its various categories, and planting all over the country, the logistics distribution problems. The idea of “Internet +” modern agriculture combines big data with fresh agricultural logistics. By analyzing the current situation and mode of logistics distribution of fresh agricultural products, we find out the weak links of fresh agricultural products logistics distribution, and analyze the best way of fresh agricultural products logistics distribution system by using big data technology, which can effectively reduce the wastage of fresh agricultural products in logistics and transportation. Provide optimization platform for logistics distribution between regions. It is expected to provide important theoretical and practical guidance for the development of modern logistics big data of fresh agricultural products.

This paper takes Qingdao subway station as an example, considers reducing the cycle of track laying on the whole line, and adds rails and wells under the existing envelope structure. The single-track row of wells and a double-line entrance to the crossing are proposed. The analytical calculations and numerical simulation methods were used to check the mechanical condition of the station envelope and the main structure of the station under the rails. The research results show that the track laying base can be laid out in the enclosed open excavation station, and a series of problems such as land occupation coordination have been solved, and the period benefit is significant. This scheme can ensure the structural safety before the entrance of the rail row well is closed, and the position of the rail side frame below the middle plate of the station satisfies the requirements of the laying limit. This method has a novel design idea, has high application and promotion value, and provides a good reference for the design and construction of open-cut subway stations.

The AZ31 magnesium alloy sheets with different microstructures and textures were produced by high strain rate rolling (HSRR) at various temperatures and strain rates. Tensile tests were carried out on AZ31 magnesium alloy sheets along rolling direction (RD), transverse direction (TD) and 45° along the rolling direction (45° RD) at room temperature. The microstructures and textures were determined. The Schmid factors (SFs) contour lines were also calculated. The tilt angle of the c-axis towards the RD affects the anisotropy of tensile strength. For the AZ31 magnesium alloy sheets subjected to relatively low strain rate rolling, the anisotropy of yield strength is comparatively obvious, due to the elongated grains. When the loading direction is close to basal plane, prismatic slip is not favored during tension deformation at room temperature. The anisotropy of yield strength mainly depends on the critical resolved shear stress/Schmid factor (CRSS/m) ratios of second-order (2nd-order) pyramidal slip.

By combining temperature-dependent x-ray diffraction (XRD) with temperature-dependent Raman scattering, we have characterized the structural transitions and lattice dynamics of the hybrid organic–inorganic perovskite CH3NH3PbI3. The XRD measurements cover distinct phases between 15 K and 370 K and demonstrate a general positive thermal expansion. Clear anomalies are found around the transition temperatures. The temperature evolution of the lattice constants reveals that the transition at 160 K/330 K is of the first-/second-order type. Raman measurements uncover three strong low-frequency modes, which can be ascribed to the vibration of the Pb/I atoms. The temperature evolution of the modes clearly catches these transitions at 160 K and 330 K, and confirms the transition types, which are exactly consistent with the XRD results. The present study may set an experimental basis to understand the high conversion efficiency in methylammonium lead iodide.

Scaffold designs in combination with drug, growth factor and other bioactive chemicals account for lasting progress of vascular tissue engineering in the past decades. It is a great achievement to adjust tissue matrix composition and cell behaviour effectively. However, regenerating the innate physiologies of a blood vessel still needs its precise architecture to supply the vessel with structural basis for vascular functionality. Recent developments in biomaterial engineering have been explored in designing anisotropic surface geometries, and in turn to direct biological effects for recapitulating vascular tissue architecture. Here, we present current efforts, and propose future perspectives for the guidance on the architectural reconstruction and scaffold design of blood vessel.

Mechanical behavior and microstructure evolution of Al?Mg?Si?Cu alloy under tensile loading at different strain rates has been investigated by mechanical property and microstructure characterization in the present study. The results show that strain rate has some influences on the flow stress, mechanical property and microstructure of Al?Mg?Si?Cu alloy. As strain rate increases, both yield strength and ultimate tensile strength increase first, and then almost remain constant, and finally increase. Strain energy density also shows the similar trend. In general, increasing strain rate is more beneficial to improve elongation, however, their relationship is not monotonic increase. Elongation difference could be reflected by the dimple distribution. The dimples in dynamic fracture zone are larger and deeper than those in quasi-static fracture zone. Microstructure in the vicinities of the fracture regions of the tensile specimens is similar and comprised of elongated grains. However, the number of low angle grain boundaries and dislocation density is dependent on the strain rate.

Surface O3 pollution mainly comes from the photochemical reaction, which is related to both meteorology and environment. Hence the formation and maintenance mechanisms of O3 include both chemical and meteorological factors, resulting in a quite difficult forecast of surface O3 pollution. In this study, the current situation of surface O3 pollution in China's typical cities in 2014 is analyzed. The pollutants and meteorological factors before and after typical photochemical pollutions are statistically analyzed, in order to extract the forecast indicators of key parameters.

Thermally activated dislocation emission in high-temperature ferroelectric ceramics is investigated through an assumption of thermal stability and a novel analytical method. The stress intensity factor (SIF) arising from domain switching is evaluated by using a Green's function method, and the critical applied electric field intensity factor (CAEFIF) for brittle fracture at room temperature is obtained. Besides, the lowest temperature for single dislocation emission before brittle fracture is also obtained by constructing an energy balance. The multi-scale analysis of facture toughness of the ferroelectric ceramics at high temperature is carried out. Through the analysis, the CAEFIF for crack extension is recalculated. The results show that the competition and interaction effects between dislocation emission and brittle fracture are very obvious. Besides, the higher critical activation temperature, the more columns of obstacles will be overcome. Additionally, the shielding effect arising from thermally activated dislocations is remarkable, thus, the brittle-ductile transition can promote the fracture toughness of high-temperature ferroelectric ceramics.

Plane strain compression tests (PSC) were conducted on as-cast AZ31 Mg alloy samples at the temperature of 400 ?C with different strain rates of 10 s?1, 80 s?1 and 160 s?1. The twinning and recrystallization behaviors close to and away from crack boundaries were characterized using Electron Backscattered Diffraction technology. The results show: (1) the twinning within the grains close to crack boundaries is more active than that far away from crack boundaries due to the local stress concentration. In addition, the rate-sensitive twinning proliferates with increasing strain rate; (2) the {10-11}-{10-12} double twinning-induced dynamic recrystallization (TDRX) can form a necklace-like structure especially within the grains close to crack boundaries. In addition to twinning, the TDRX also presents the rate sensitivity and becomes more active at the higher strain rate due to the higher flow stress; (3) the failure strain of PSC tests first decreases and then increases with increasing strain rate. This phenomenon strongly depends on the strain-rate controlled competition between twinning hardening and TDRX softening.

We demonstrate a facile and versatile method to grow Ru particles uniformly on pristine few-layer graphene (FLG) in supercritical diethylamine. In particular, a large number of Ru subnanometer clusters less than 1.0 nm were observed. The particle size can be tuned by manipulating the loading content of Ru and controlling the reaction temperature. The resulting Ru/FLG showed remarkably high activity, selectivity, and reusability towards the hydrogenation of levulinic acid to γ-valerolactone. This method is flexible, and can be extended to the synthesis of a variety of other ultrafine metal particles supported on FLG.