To solve the inevitable shortcomings of single sensor environmental perception system, the LiDAR and camera were fused to combine the advantages of the two sensors and form complementarity for improving the environmental perception capability of unmanned vehicles. The fusion technology of LiDAR and camera was investigated and applied for the target recognition at urban intersections. Combining the search theory of Flood Fill algorithm with the tangent theory of spectral clustering algorithm, and considering the Euclidean distance and spatial distribution characteristics between point clouds, the laser radar target detection method was investigated. The target recognition method based on the fusion of LiDAR radar and camera was proposed, and the traditional PnP solving principle was analyzed. The pose transformation relationship was solved based on the plane normal alignment, and the genetic algorithm was introduced to optimize the solution results. The fusion results of LiDAR and camera were simulated and verified by the autonomous driving simulation software. The results show that by the proposed fusion method of LiDAR and camera, the vehicle targets at urban intersections can be accurately recognized, and the unmanned vehicles can perceive targets within 360° range. This can ensure the safety of unmanned vehicles and improve the environmental understanding ability.

To address the urban distribution route optimization issue in cold chain logistics, the new model of multitemperature codistribution with soft time windows for electric vehicles was proposed for the lowcost and highefficiency needs of logistics enterprises. Based on the cooler and insulated boxes, the different temperaturelevel goods were delivered simultaneously by ordinary electric vehicles for improving vehicle utilization. The improved ant colony algorithm was proposed to solve the problem, and the 2optimization（2opt） algorithm was combined with the ant colony algorithm to enhance the local search capability. The effectiveness of the model and algorithm was verified through case analysis based on the Solomon dataset. The results show that compared to the single temperature distribution, the proposed multitemperature codistribution can reduce delivery costs and improve efficiency. As the width of time windows is expanded, the number of vehicles is decreased, and the delivery cost shows decreasing trend. After the number of vehicles is reduced to the minimum, the total cost continues to decline slowly due to the continuous reduction of incentive costs and spoilage costs.

To solve the delay problem between sensor perception and V2V communication in the intelligent networked environment, the dual delay multiple lookahead full velocity difference (DDMLFVD) model was proposed with considering dual delay and multiple front vehicle feedbacks. The dual delay information was introduced according to the sensing characteristics of intelligent connected vehicles, and the DDMLFVD model was proposed by combining the multivehicle speed differences and the desired speeds. The tiny perturbation method was utilized to solve the critical stability conditions of the DDMLFVD model, and the effects of the vehicle number in front of ego vehicle and the delay value on the stability domain of the model were investigated. The model was simulated and analyzed by the straight road scenario, and the stability effect of DDMLFVD on traffic flow under variable disturbance and variable delay scenarios was emphatically investigated. The results show that by the proposed DDMLFVD model, the disturbances can be well absorbed in the face of complex disturbances, and the stability of traffic flow can be improved.

To solve the safety problem of automobile side collision, the safety performance of the driver side door was optimized and analyzed by combining simulation analysis and mathematical optimization with passenger car door as research object. According to the test requirements of GB/T 37337—2019 of protection of the occupants in the event of a lateral pole collision, the lateral pole collision simulation model was established, and the reliability of the simulation model was analyzed. The safety performance indicators of the intrusion of the side wall of vehicle, the energy absorption of each component of the door and the acceleration of vehicle were investigated. By designing the sample data of the Latin experiment, the response surface model of the optimization target was established, and the multiobjective optimization solution of the established optimization mathematical model was obtained based on the nondominated sorting genetic algorithmⅡ（NSGAⅡ）. The Euclidean distance of the Pareto front solution was calculated by the entropyTOPSIS method, and the final optimization scheme was determined. The results show that when the door mass is reduced by 1.22%, the maximum intrusion of the door is reduced by 10.28%, and the proportion of energy absorption of the main energyabsorbing parts of the door is increased by 16.14%, while the peak acceleration of the door is reduced by 7.58%. The optimized door is improved to different degrees in terms of intrusion, acceleration and energy absorption, which can enhance the door impact intensity and improve the side impact safety of car. The peak acceleration of the vehicle is reduced by 16.37%, and the secondary impact force on the occupants is relieved.

To effectively remove liquid water in the channel, the effect of partial blockage in the fuel cell channel on the droplet transport process was investigated by the volume of fluid model (VOF) method, and the effects of blockage block shape parameters, droplet size and gas diffusion layer (GDL) surface wettability on the twophase transport characteristics in the channel were explored. The results show that the presence of block affects the droplet transport in the channel. The introduction of block can increase the droplet shear force in the y direction, which increases the droplet transport rate and facilitates the removal of liquid water from the GDL surface. As the blocking ratio and longitudinal ratio increase, the pressure drop in the channel is increased, and the droplet transport rate is accelerated. With the increasing of droplet diameter and contact angle of GDL surface, the droplet transport rate is increased. When the droplet diameter is 0.8 cm with the GDL surface contact angle of 150°, the droplet transport rate in the channel is fast.

Based on the structure of power battery liquid cooling plate, the structure of the liquid cooling plate was optimized to realize uniform mass flow distribution. Through the Isight optimization platform integrated modeling software of CATIA and the computational fluid dynamics simulation software of STARCCM+, the optimal Latin hypercube method in the experimental design was used to generate sample points in the design space. On the basis, the response surface approximation model of each flow channel mass flow value was established. For the target, the combined optimization strategy of multiisland genetic algorithm and sequential quadratic programming method was used to optimize the response surface model for obtaining the optimal design. The joint model of liquidcooling plate battery pack was established for thermal simulation verification, which was used to verify the established optimization model. The results show that the error between the mass flow distribution of each flow channel of the liquid cooling plate and the target mass flow value is less than 5%, and the maximum temperature of the optimized battery module is reduced by about 2 ℃.

To investigate the hydrodynamic cavitation phenomenon in microchannel devices, the influence laws were analyzed from three aspects of geometric shapes and dimensions of flow restrictive elements, working fluids and channel roughness. The common shapes of flow restrictive elements are mainly microorifice, microventuri, microdiaphragm and micropillar. Different geometries of flow restrictive elements have different cavitating flow characteristics. The dimensional parameters of the flow restrictive elements and the scale effect caused by the size reduction play an important role in the cavitating flow patterns. The commonly used working fluids contain deionized water, ethanol, phosphatebuffered saline (PBS), refrigerant (R123), poly(vinyl alcohol) (PVA)，microbubbles (MBs) suspension, perfluoropentane (PFC5) suspension, titania nanoparticle suspension, binary liquid mixtures, etc. Compared to water, the remaining working fluids can increase cavitation intensity to different degrees. The introduction of roughness is mainly realized by the surface roughness elements and sidewall roughness elements of the channel, and the cavitation intensity can be significantly improved compared to that of the smooth surface. Microchannel hydrodynamic cavitation devices are mainly used in energy harvesting, liquidphase exfoliation and biomedical fields. Based on the research status of microscale hydrodynamic cavitation at home and abroad in recent years, the potential research directions and application trends of hydrodynamic cavitation phenomena in microchannel devices are provided.

To investigate the pressure pulsation characteristics of multiwing centrifugal fans in the rotational stall stage, taking the multiwing centrifugal fans as research object, the Creo software was used to model in three dimensions, and the models were meshed and calculated for unsteady values. Monitoring points were set in different circumferential, radial and axial positions of the impeller outlet, and the internal pressure pulsation law of the fan under the rotational stall condition was analyzed. The calculation results show that the pressure coefficient of the monitoring point at the diaphragm tongue is the largest, and with the decreasing of flow, the intensity of pressure pulsation is increased. The impeller outlet is affected by the dynamic and static interference between impeller and volute, and the amplitude of the pressure coefficient is the largest. When it moves radially to the volute wall, the pressure pulsation degree is weakened. The law of pressure pulsation is slightly affected by the axial position change，while the change of rotational stall degree can cause the change of pressure pulsation. The stronger the rotational stall is, the more intense the pressure pulsation is. The wider the lowfrequency pulsation range is, the higher the stall frequency amplitude is.

To solve the poor performance problem of the existing solutions based on filters, dynamic analysis and static analysis in detecting unknown XSS attacks, the machine learning methods were used to efficiently detect unknown XSS attacks, and the XSS attack detection model was proposed based on genetic algorithm and support vector machine. The fuzzy testing was used to generate XSS attack pre samples, and the genetic algorithm was used to search the feature space. The optimal test cases were iteratively generate, and the dataset was expanded to enrich the XSS attack vector library. The attack detection model was proposed based on genetic algorithm and support vector machine, and the coding rules for XSS test cases were determined. The fitness function was designed, and the designs of selection operator, crossover operator and mutation operator were completed. The detection performance of the classifier was evaluated based on accuracy, recall, false positive rate and F1 score. The results show that the accuracy of the model can reach 99.5%. Compared with other detection methods, the proposed detection model has better detection performance with high recall rate and low false positive rate.

To solve the problem of low message authentication efficiency in the internet of vehicles (IoVs) caused by limited network bandwidth and computing power, the certificateless batch authentication scheme applied to the IoVs was proposed. The authority generated evaluation proof for each registered vehicle and calculated global commitment based on all registered vehicles. The vehicles participated in the message authentication process based on the evaluation proof. In the authentication process, the global commitment could be utilized by the trusted authorities to check the validity of vehicle evaluation proofs through bilinear pairing for realizing rapid batch authentication. For the privacy and security, the zeroknowledge proof was introduced by the proposed scheme based on the blockchain architecture, which provided privacy protection properties of anonymity and unlinkability for vehicles. The accurate traceability and fast revocation were realized through the blockchain state database. The security analysis, computational efficiency analysis and simulation experiments were conducted. The results show that the proposed scheme can satisfy various security requirements of anonymity and unlinkability, and the average authentication time is 0.357 ms, which is at least 12.46% better than those of existing schemes.

To solve the problem that the previously constructed Sboxes based on chaotic systems were difficult to achieve good cryptographic performance, the design scheme for Sboxes was proposed based on hyperchaotic system and genetic particle swarm optimization algorithm. Introducing sine and cosine functions and exponential factors, the twodimensional hyperchaotic system was constructed based on the onedimensional chaotic mapping. The performance analysis was conducted by system bifurcation diagram, phase diagram and Lyapunov exponent diagram to reveal that the chaotic system exhibited continuous hyperchaotic intervals in the parameter range with complex chaotic behavior. By varying initial values, parameters and iteration times of the chaotic system, Sboxes were dynamically generated. Combining particle swarm optimization algorithm and genetic algorithm, the genetic particle swarm optimization algorithm for Sboxes was proposed, and the Sboxes generated by chaotic system were used as initial population. The particle swarm optimization algorithm was leveraged to enhance the crossover operation in the genetic algorithm, and a new mutation strategy was introduced in conjunction with hillclimbing algorithm. To verify the performance of the generated Sbox, the simulation tests were conducted on bijective property, nonlinearity, strict avalanche criterion, differential probability and bit independence criterion. The simulation results show that the proposed optimization algorithm can generate Sboxes with good performance in terms of nonlinearity, differential uniformity and bit independence criterion.

To further improve the cooling performance and operation stability of system, the gasliquid separator enhanced loop thermosyphon/vapor compression hybrid system was proposed. In the thermosyphon mode, the separator was used to reduce the pressure drop of fluid in the twophase tube for improving the performance of steadystate heat transfer and startup and the operation stability of system. In the vapor compression mode, the separator was used to make the saturated vapor into the condenser for increasing the mass flow rate in the condenser and enhancing the system coefficient of performance (COP). The simulation model of the hybrid system was developed to investigate the impact of structural parameters on thermosyphon mode performance. The difference of refrigeration performance between the new system and the conventional system in vapor compression mode was comparatively analyzed under the given structural condition of system. The results show that the system performance is the best when the inner diameters of twophase tube and gas tube are respective 10 mm and 9 mm with separator height and total system height of respective 1.05 m and 1.45 m. Compared with the conventional system, the new system can achieve better performance under any operating condition, and the maximum COP of the new system is improved by 19.70%.

The reaction kinetics mechanisms of KAUST PAH mechanism 2（KM2） and AramcoMech are commonly used to simulate and predict the generation of polycyclic aromatic hydrocarbon(PAH) and soot. The two kinetics mechanisms were evaluated based on the flame multiparameter measurement data using methane mixed with ethylene opposed diffusion flame as research carrier. The results show that the two mechanisms can accurately predict the thermochemical structure of methane mixed with ethylene diffusion flame. However, the prediction performance of the influence of methane mixing on PAH and soot generation is poor. Neither mechanism fails to predict the inhibition of PAH and soot generation in methane mixed with ethylene flame. Comparing the similarities and differences of PAH and soot generation paths between the two mechanisms, it is found that both mechanisms overestimate the sensitivity of propargyl radical（C3H3·）generation to methane blending. The flame multiparameter measurement data are helpful to further optimize and verify the reaction mechanism of methane fuel.

To investigate the influence of water film produced by the liquefaction of saturated sand with weak permeability on the distribution of sand strength and deformation index, the onedimensional finite difference model of liquefied water film in saturated sand was established to simulate the formation mechanism, development and dissipation process of water film in the liquefaction process of saturated sand with weak permeability fine sand, and the relationship between the water film and the characteristic parameters of soil layer for especially the interlayer. The results show that there is obvious plateau stage in the process of excess pore water pressure dissipation, and the starting and ending points have good relationship with the formation of the maximum thickness and disappearance of the water film. The formation and development of water film is closely related to the duration of high pore pressure. In the case of weak permeability interlayer, the water film is produced under the interlayer, and the duration of high pore pressure application in saturated sand is significantly longer than that without interlayer, which has adverse effect on soil deformation. The rationality of the model is verified by comparing with the experimental results.

The novel Fe doped carbon dots (FeCDs) with good photoluminescent properties were rapidly synthesized by microwaveassisted method with ferric citrate and polyethyleneimine as raw materials. The results show that the FeCDs have good stability under the conditions of broad pH range from 3 to 9, high ion strengths and long storage time. The prepared FeCDs can easily penetrate and accumulate into the cell, which can be used as effective probe for biological imaging of A549 cells. The FeCDs display distinct peroxidaselike (POD) activities, which is evidenced by the catalyzed oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) into blue oxidized products in the presence of H2O2. A colorimetric method for the determination of H2O2 is established based on the results. Under optimal reaction conditions, the colorimetric method for H2O2 detection is constructed with good linear relationship from 0 to100.00 μmol/L and detection limit down to 0.13 μmol/L. The highly selective and ultrasensitive method is successfully applied to detect H2O2 inside A549 tumor cells with good recoveries of 98.4%-102.8%, which can verify the proposed method.

The crystal structure, electronic structure and the effect of spinorbit coupling (SOC) on the magnetic and electronic properties of double perovskite Ba2CoOsO6 were systematically investigated by firstprinciples calculations. Through the coupling analysis of electron structure and spin orbit, the influence on the macroscopic physical properties was discussed. The results show that Ba2CoOsO6 is antiferromagnetic semiconductor material with narrow band gap and disordered Os1/Co1 defects. The electronic structure analysis confirms that the charge combination of Ba2CoOsO6 is Ba2+2Co2+Os6+O2-6, which verifies the existence of Co2+ and Os6+. The spin magnetic moment of Co and Os ions is decreased by SOC, and the band gap is narrowed. The results of firstprinciples calculations show that the effect of spinorbit coupling on electronic structure and electromagnetic properties can not be ignored. Compared with other methods, the calculated values are closer to the results of experimental analysis, which can verify the theoretical calculation.