The rare ginsenoside Rg5 was efficiently prepared in the presence of molecular sieves. using the multi-functional improved Soxhlet extractor as extraction tool and ginseng fibrous root powder as raw material, hydrochloric acid as catalyst. The extraction process of ginsenoside Rg5 was optimized through one-factor experiment. The optimum result obtained from one-factor test was as follows: extraction solvent was 30 mL methanol, 4A molecular sieve was 0.3 g, the heating temperature in the extraction barrel was 65 ℃, and extraction time was 4 h. Under the optimized conditions, the extraction yield of total ginsenosides reached 10.2% and the yield of rare ginsenoside Rg5 was 3.20%, which could significantly improve the preparation efficiency of ginsenoside Rg5 compared with the traditional Soxhlet extractor. The method has following characteristics such as high extraction yield and simple operation, which indicated the method could extract Rg5 effectively.

The absorbance of lead in flour was determined by microwave digestion method and atomic absorption spectrophotometer. Box-behnken Design was used to determine the best instrumental analysis conditions. Through the single-factor test, the four factors of ashing temperature, ashing time, atomization temperature and atomization time were selected for the three-level test. The mathematical model was established by Box-Behnken Design, and the optimal conditions were sought by variance analysis, response surface analysis and desire function optimization. Results show that the established mathematical model of the R²=0.9671，R²_Adj =0.9342 shows that the model has good credibility, this model could be used to predict the coefficient of variation CV % = 3.08%, indicates that under the condition of the experiment, variation is small, the model has good repeatability, when ashing temperature is 525℃, ashing time is 20s, atomization temperature is 1550℃, atomization time for 5s absorbance maximum 0.24; Therefore, this study can provide a good theoretical basis for the determination of lead by atomic absorption spectrophotometer.

This design is about a certain specification range of l-shaped plate grab flexible manipulator design. The main workflows include the grab of l-shaped plate, positioning welding and hull welding, etc. This paper discusses the design background, design principle and work flow of flexible manipulator in detail. The design of l-shaped plate grasping flexible manipulator realizes the perfect combination of industrial robot, flexible fixture and intelligent welding technology.

Taking the O-shaped rubber ring in the reciprocating seal of the Hydraulic cylinder as the research object, a two-dimensional axisymmetric model was established. With a friction coefficient of 0.1, different medium pressures and different pre-compression ratios, the finite element software ANSYS workbench is used to analyze the deformation and stress of the O-ring during installation, static pressure and working conditions. The results indicate that: when the compression rate exceeds 15% during reciprocating motion, it is easy to cause O-ring stress relaxation, compression permanent deformation, and loss of sealing ability; and the seal ring has the most obvious stress concentration in the gap between the cylinder and the piston rod. In this position, it is easy to be squeezed into the gap, causing gap bite, resulting in seal failure; in the case of oil pressure less than 15MPa, the shear stress is always less than the shear strength of nitrile rubber, but under the reciprocating movement, the sealing ring will continue to It is easy to accumulate damage by friction and wear, leading to cracks or damage.

Cavitation in the diesel nozzle can have a serious impact on the performance of the diesel engine. On the one hand, it promotes the atomisation of the fuel, enabling efficient and sufficient combustion of the fuel inside the engine and reducing the possibility of carbon build-up. On the other hand cavitation can cause cavitation wear inside the nozzle, thus affecting the life and performance of the nozzle. This paper investigates the effect of nozzle structural parameters on cavitation performance through computational fluid dynamics using a VOF model plus a cavitation model. Three dimensionless quantities, the gas-liquid inlet angle ratio, the gas-liquid inlet length ratio, and the gas-liquid inlet diameter ratio, are analysed using the dimensionless quantity method. To provide a theoretical basis for future research into the fuel atomisation characteristics of gas-liquid two-phase fuel nozzles.

Based on relevant theories and methods such as business process reengineering and procedure analysis, this paper studies the optimization of outpatient process in hospital by taking the gastroenterology department of R hospital in J city as an example. Through field visits and questionnaire surveys, problems in the current service process in the gastroenterology department are found. Based on business process reengineering theory, this paper optimizes the outpatient process, and uses procedure analysis and Flexsim simulation to do the contrastive analysis of out patient process, which verifies the effectiveness of the optimization scheme.

In order to achieve the voltage regulation for high power switched-capacitor converters,the voltage regulation method of LC equivalent circuit using capacitor charging  loop is studied.The concrete implementation is that the analysis on the charging current and the charge-discharge process of the capacitors is made,then the output voltage regulation can be realized by changing the switching angle of the sinusoidal charging current.At the same time,it is necessary that the third quadrant operation of MOSFETs and special stray inductance arrangement be utilized in order to reduce the power dissipation and EMI noises from stray inductors in switches.The analysis and experiment results,on which voltage doubler has been built using two switched-capacitor prototype boards with variable output voltage regulation capability,show that the proposed voltage regulation method can not only achieve the soft switch function,and its efficiency can exceed the theoretical maximum efficiency value by traditional method.

Based on the basic principle of 6~10KV line over-current protection, design the on-site simulation realization under laboratory conditions and the simulation realization on the Multisim software platform. In the laboratory field simulation design, the principle wiring diagram-expand the wiring diagram-the design idea of the experimental wiring diagram, equipment selection and connection, a detailed equipment list and operation process, and finally recorded experimental simulation data. In the simulation design of the Multisim software platform, the field simulation experimental wiring diagram is the design basis Design the simulation circuit, and the equipment selection focuses on the presentation of functions. The connection structure of the equipment can be adjusted appropriately without affecting the actual function, and the simulation can be carried out in accordance with the on-site simulation operation sequence.The realization of virtual simulation must be based on the laboratory simulation data, and the two cooperate with each other , Learn from each other to achieve better teaching and learning results.

Based on the analysis of the structural characteristics of the existing sweeper, a sweeper with simple structure and high cleaning quality is designed. In this paper, the system composition and working principle of the sweeper are discussed in detail, including cleaning mechanism, reverse cleaning mechanism, filtration device, spraying self-cleaning device, walking mechanism, lifting mechanism, auxiliary mechanism, etc., in order to provide technical reference for the design of the small sweeper.

Skiing is a popular winter sport. In order to realize the beginner's quick start and the simulation of skiing process, an indoor skiing posture training simulator based on VR is designed. The simulator consists of three parts: virtual simulation system, sports training system and safety protection system, VR virtual simulation system can simulate the skiing training scene and increase the reality of skiing; the sports training system includes a variety of institutions to maximize the simulation of skiing posture; the safety protection system can protect users; the trainer combined with VR technology can realize the multi-dimensional simulation of skiing posture under the real skiing scene experience, so that the skier can experience the real body feeling when simulating the sports, and improve the real scene feeling of the experience person simulating skiing significantly.

The flexible joint was made with two different materials of silicone tube and elastic skeleton, and the static experiment was performed on it. The bending angle and clamping force under the same air pressure were obtained, and the deformation model of the flexible joint was established, and the air pressure was obtained. Deformation characteristics under. The research results show that the smaller the Shore hardness of the silicone rubber tube is, the smaller the shear elastic modulus and the elastic modulus, and the better the flexibility and mechanical properties of the flexible joint of the silicone tube. This research lays the foundation for further research on the application of elastic silicone tube in pneumatic manual actuator.

Aiming at the problem that the overshoot of the traditional optimization algorithm in the optimization of PID parameters is too large due to the improper selection of objective function, which results in the slow reaction speed and poor stability of the system, a new method based on the traditional genetic algorithm and introducing penalty function is proposed to construct a new one according to the overshoot in the system. The objective function is used to optimize the parameters of PID. Experiments show that this method can effectively reduce the overshoot in the system, speed up the optimization and operation speed while ensuring the stability of the system, and realize the optimization of PID parameters.

Aiming at the problems of a time-consuming, difficult and complex operation in ROS environment, a model building method of external robot model import was proposed. The ROS operating system was used to build the model simulation platform, and SolidWorks software was used to generate the URDF file that could be executed by the ROS platform to complete the 3D modeling of the robot. The 3D model is displayed in Rviz and Gazebo for simulation verification after URDF file parsing, which can realize the autonomous control of the robot. It is of great significance to the research on the mapping and path planning algorithm of wheeled robots.

Is common in urban and rural residential parking problems such as insufficient parking Spaces, access time is too long, in order to improve the vehicle's access policy, vehicle access time as objective function, using the queuing theory, respectively, set up priority save car, first car, sequential access, interleaved, such as the mathematical model of different routes, the working efficiency of the different access strategy to make use of the MATLAB simulation calculation, through contrast to choose the appropriate access strategy, the ideal way of access strategy, improve the utilization rate of parking Spaces and effectively solved the three-dimensional garage the existing problems, and widely used.

With the development of information construction and the popularization of LAN, most of the core data and customer information of enterprises are stored in the database of enterprises, including the core production technology, production data and enterprise internal information, etc., from which it can be seen that the network security of enterprises is how important.This paper mainly discusses the process of internal network penetration and relevant defense measures, so as to give relevant Suggestions to enterprise network managers.

Ethylene oxide is a kind of widely used organic compounds. The marginal profit level is comparatively higher all the time. Most petrochemical enterprises are equipped with this production equipment in our country. In the ethylene oxide factory measurement, there are often differences between truck scale and mass flowmeter measurement, which sometimes leads to measuring trade disputes. This paper analyses the reasons for dispersion, and puts forward countermeasures with the hope of protecting the mutual interest of buyers and sellers and promoting fair trade.

Tibouchina aspera is an excellent ornamental plant in Landscape ar-chitecture. In this paper, based on a 30-day cutting experiment, the effects of different substrate ratios on the growth of the cuttings of Paeonia suffruticosa were compared, and the rooting time, root number, longest root length, rooting rate, growth state of cuttings and substrate changes were analyzed. The results show the ratio of treatment group T8 (original soil: fine sand: peat soil: vermiculite: perlite) = 1: 1: 2: 1: 1 has the fastest rooting rate of cuttings, longest root length and best cutting growth among all experimental treatment groups. The treatment effect of T (peat soil) comes second, and it can be used as a backup plan for production under limited conditions.

Based on chebyshev approximation, an integer-order spectral operator differential matrix is derive, and a recurrence scheme for computing fractional spectral differential operator matrix is also obtained by using the three terms recurrence of chebyshev polynomials and the derivatives of chebyshev polynomials. Numerical examples are given to demonstrate the accuracy and effectiveness of the scheme.

The method of probability theory is a specific strategy to analyze, dispose and solve the problems of probability theory, with its features of randomness, generality, hierarchy, pertinence, integration and manipulity. The strategy of efficient implementation of probability theory is to clarify problems through association to bridge the known and unknown channels; to acquire construction through common models to solve problems directly or indirectly; to be reflective through review to refine innovation on probability models and methods.

Based on the first principle density functional theory and perturbation theory, the Exchange Correlation Energy Approximation (GGA) 、Local Density Approximation (LDA) and the pseudo potential approximation (TM) are employed. The relationship between lattice structure and protocell parameters of transition metal iron with 8 outer valence electrons and 16 outer valence electrons is calculated. It is suggested that 3s²3p⁶ should be regarded as the outer electron when calculating the melting temperature of transition metal Fe.