Based on modal theory, modal analysis of an industrial robot was carried out by simulation and experimental methods. Firstly, a three-dimensional model of the robot was established in a typical posture, ANSYS Workbench software and ADAMS software were used to analyze the theoretical mode of the robot, dynamic characteristics such as natural frequency and mode shape were obtained, and the weak vibration part was determined. Secondly, the hammer method was used to carry out the modal analysis of the robot experiment and the vibration test of the robot was used to verify the correctness of the simulation results. Finally, the optimization solution was proposed for parts with severe vibration. The analysis results show that the robot joint 2 and joint 3 are prone to low-frequency vibration, and the rigidity of the small robot arm is relatively weak compared with other parts. The results can provide theoretical and experimental references for robot optimal design and work performance improvement.

To solve the problem of difficult power supply for the equipment in the pressure regulating station along the natural gas pipeline, a small power generation control system suitable for 10~40 kPa natural gas low-pressure differential power generation was designed. The domestic chip was selected as the main control chip of control system, and the permanent magnet synchronous generator PMSG was selected as the energy recovery device of front end. In the designed hardware circuit of the control system, the maximum power point was used as the control output, and it met the explosion-proof requirements by using the intrinsically safe circuit. Lithium titanate battery was used as energy storage and instrument equipment. In the program design, the control of pipeline solenoid valve was realized to solve the problem of input overload under the condition of fully charged battery and excessive high voltage difference, and a variety of protection strategies were used to prevent the high voltage after rectification from damaging the components. The performance of the control system was tested through the construction of the test-bed, and the function basically can meet the expected requirements.

Aiming at the difficulty in detecting the amount of silicone oil injection caused by the small gray difference between the neutral transparent refill and the colorless silicone oil, a new method and system for detecting the injection amount of colorless silicone oil based on machine vision was proposed and designed. An image acquisition unit and an external light source control unit were the main hardware part of the system. By adjusting the illumination angle of the external light source, the enhancement of the gray difference in the colorless silicone oil area can be realized. In the part of software and algorithm, a gray region histogram algorithm was used to select the corresponding region of interest (ROI) and parameters on the constructed human interaction interface, and the length detection results were displayed in real time. The experimental results show that the system can accurately detect the continuous length of silicone oil, the system has good real-time performance and stability, high accuracy, and has a certain value of promotion and application.

Aiming at problems of slow convergence and long time consuming in trajectory tracking, and chattering problem exists in the control of Mecanum wheel omnidirectional mobile robot based on general sliding mode, a sliding mode control method was proposed to realize the rapid convergence of the system by using the multi power reaching law. The position change of three degrees of freedom of robot was realized by controlling the angular velocity of four Mecanum wheels, and the control of three inputs and four outputs was completed. According to the mathematical model established, the multi power reaching law was used to adjust the convergence speed at different stages of the system approaching sliding mode surface, and the hyperbolic tangent function was used to replace the sign function in the reaching law to improve the chattering problem. The stability of the three inputs and four outputs control system was proved by Lyapunov theory. Finally, the control effect of the proposed algorithm was illustrated by simulation and comparison analysis.

During the production of hot rolled H-beam, two linear cracks with the same position and similar morphology will appear at the R-angle connecting the web and flange, and close to the side of the web. In order to distinguish these two kinds of defects effectively, the macro and micro analysis of the two kinds of linear defect structures were carried out by means of on-site sampling, experimental analysis, production data statistics, metallographic observation and scanning electron microscope. The results show that both the causes and the production processes of the two linear cracks are all different. One is the hot crack generated from the billet, and the web crack at the R-angle is formed after the later heating and rolling. The other is the cold crack generated by the straightening process, and the straightening crack is formed at the R-angle of the finished product.

Combining resistant starch and resistant maltodextrin which directly affecting the composition of human intestinal microbiota and fermentation capacity in different ways, a compound cellulose tablet candy with the function of moistening intestines and defecating was developed. The combined use of sugar alcohol sweetener isomaltitol and mannitol was researched by the experiment, so that the sweetness of the product has a soft and mellow taste. The sour agent DL-malic acid was used to make the sour taste of the product round, slow but long-lasting stimulation. The lubricant magnesium stearate can prevent the tablet from sticking and punching. It was prepared by the wet granulation and tableting process. Taking sensory evaluation as an indicator of the product,  single factor test and orthogonal design test were conducted, and the quality was evaluated through the difference in tablet weight, hardness and friability. The best ratio of the test is 72% composite cellulose powder, 13% isomaltitol, 13% mannitol, 0.25% DL-malic acid, 1.0% magnesium stearate, average tablet weight 812 mg, average hardness 488.01 kPa, friability <1%. The tableted candy prepared by the formula has a smooth surface, a suitable taste and moderate hardness, which is suitable for the consumption needs of people of all age groups except infants, pregnant women, and nursing mothers, and has strong health significance and broad market prospects.

The aim of this study was to determine the chemical constituents of volatile constituents from Isatidis Radix, and evaluate the antimicrobial and antioxidant activities using in vitro assays, including disk diffusion test, prussian blue test, ferric reducing antioxidant power and 1, 1-diphenyl-2-trinitrophenylhydrazine free radical (DPPH·) scavenging activity. Results showed that the volatile constituents of Isatidis Radix had low content (0.038%) and comprised of isothiocyanates, aromatic hydrocarbons, carboxylic acids, etc., which were identified by NIST Library. The volatile constituents of Isatidis Radix had antibacterial effects on Escherichia coli and Staphylococcus aureus, and the average antibacterial zone diameters were 8.1 mm and 6.5 mm, respectively. Also, it had good reducing ability, and obvious scavenging effect on DPPH·, with IC₅₀ value of 7.169 mg/mL.

The molecular dynamics method was used to construct the bio-based rejuvenator-asphalt model, and the fusion diffusion behavior of bio-based rejuvenator-asphalt was investigated by microscopic simulation. Firstly, the FTIR test combined with the SARA model was used to determine the molecular structure of 12 kinds of asphalt before and after aging. And the main components of animal waste bio-based rejuvenators including steroids and carboxylic acids were selected to establish the molecular dynamics model of the asphalt-rejuvenator diffusion system. Furthermore, the density and compatibility index were used to verify the reliability of the molecular dynamics model, and the fusion diffusion behavior of bio-based rejuvenator in virgin asphalt and aged asphalt were analyzed under different temperatures and aging conditions . The results show that the diffusion coefficients of bio-based rejuvenator in aged asphalt is higher than that in virgin asphalt. The diffusion performance of steroids is better than carboxylic acids at the same temperature. The diffusion coefficients of two bio-based rejuvenators increase with the increase of temperature, since the greater kinetic energy at high temperature makes it easier for the system molecules to get rid of the constraint of molecular force.

In order to obtain the quantitative integration results of the relationship between online brand community customer interaction and customer loyalty, and understand the relationship between them in the clothing field, the meta-analysis method was used to study 5137 independent samples of 16 related literatures published at home and abroad from 2011 to 2020. It was found that all dimensions of online brand community customer interactions play a moderate role in promoting customer loyalty and community types play a moderating role in the relationship between customer interaction dimensions and customer loyalty. A phased summary of the research between the two was made, research focus was adjusted according to their own community types while customer interaction had been concerned, and the relationship between them in the clothing field was predicted. Finally, some suggestions were put forward for the community operation of clothing online brands.

In order to improve the fit of young men's tops, 300 young men aged 18~25 years old in Anhui areas were selected as the research subjects. Relevant datas on seven main upper body parts were collected by 3D body scanner, and factor analysis was performed through SPSS software, and three common factors of horizontal factor, length factor and girth factor that affecting upper body shape characteristics were obtained. The weight of each factor was calculated, and three characteristic indexes, namely height, waist circumference and chest waist difference were selected. Finally, it was determined that the upper body shape of young men was tall and thin, short, medium height and thin, and medium height and fat, accounting for 25.09%, 28.00%, 37.09%, 9.82%. The research results are helpful to understand the characteristics of human body shape in Anhui areas, and provide feasible reference for regional garment enterprises in improving garment structure.

A method based on monocular vision and ultrasonic ranging for the intelligent Raspberry Pi robot for detecting static and dynamic obstacles was proposed. An improved monocular visual obstacle detection algorithm was applied to perform contour detection on indoor static and dynamic obstacles, the distance was measured between the robot car and obstacles with an ultrasonic sensor. For static obstacle detection, image enhancement was introduced in the image preprocessing stage, and different obstacle color features were extracted through HSV images to improve the efficiency and accuracy of obstacle contour calibration. For dynamic obstacle detection, background difference was combined with 3D image display technology to achieve dynamic target capture, and a distance decision module was set up to record obstacle location information. The experimental results show that the method can  effectively reduce the average consumption time of obstacle detection, and improve the accuracy of indoor obstacle detection.

The operating space of rail transit system is relatively closed. In order to ensure the safe operation of the subway, it is of great significance to explore the chain effect formed by the mutual transmission of risks. Based on the risk chain theory, the research on the risk factors, pregnancy risk environment, and carrier characteristics of urban rail transit fire events were conducted. The chain transmission effects formed by the mutual transfer of subway fire risks were analyzed. A subway fire risk chain evolution network model was established, four evaluation indicators in the complex network theory including access degree, numbers of subnet nodes, betweenness centrality and tight centrality were adopted, and the importance of fire risk network nodes was comprehensively evaluated. The results show that there is strong transmissibility between model risks, and the open fire in the subway station is the key node for risk control. The research results can provide theoretical support for controlling risk transmission from the perspective of subway fire risk chain, reduce the probability of key risks in the process of fire transmission, and avoid more serious consequences caused by secondary disasters and derivative disasters.

Most of current thermoporoelastic models of porous media are incomplete coupled ones, and the physical models mostly adopt one-dimensional or one-dimensional axisymmetric models. In view of this point, a fully coupled model of a two-dimensional saturated porous media flat plate was presented and the corresponding numerical simulation was carried out. The fully coupled of three physical fields (heat, fluid flow, and solid stress/deformation) were realized by means of strong coupling. The boundary conditiorns were assumed as follows: As for the temperature field and the displacement field, 30 ℃ fluid and solid temperature boundary conditions and fixed displacement boundary conditions were exerted on the left side of the plate, and naturual boundary conditions were prescribed on the other sides of the plate. Meanwhile, 0 Pa pore pressure boundary conditions were loaded around the plate. The numerical solutions of flow field, strain field and two temperature fields were obtained by the PDEs pattern of COMSOL Multiphysics FEA software. Numerical results showed that fluid and solid temperature, strain and pore pressure transfer along the x-axis direction with increasing time, and the strain in the x-direction is much larger than that in the y-direction. In addition, it was found that the maximum values of y-direction strain and pore pressure gradually decrease with time. The presented mathematical model and numerical solutions are of benefit to provide deep insights into the fully thermoporoelastic coupled behavior of two-dimensional saturated porous media.

Let

be a proper

k-total coloring of a graph G. Define a weight function on total coloring as

$ \phi (x) = f(x) + \mathop \Sigma \limits_{e \mathrel\backepsilon  x} f(e) + \mathop \Sigma \limits_{y \in N(x)} f(y) $

, where

$ N(x) = \{ y \in V(G)|xy \in E(G)\} $

. If

$ \phi (u) \ne \phi (v) $

for any edge

$ uv \in E(G) $

, then f is called a neighbor full sum distinguishing k-total coloring of G. The smallest value k for which G admins a neighbor full sum distinguishing total coloring with k colors is called the neighbor full sum distinguishing  total chromatic number of G and denoted by

${\rm{ftnd}}{{\rm{i}}_\Sigma }(G)$

. The research conjectures that

${\rm{ftnd}}{{\rm{i}}_\Sigma }(G) \leqslant \Delta  + 2$

for every graph except for

$ {K_2} $

, where ∆ represents the maximum degree of G. Meanwhile, we get this parameter for Cartesian product graphs of paths and paths, paths and cycles are ∆ + 1, respectively, which confirm the above conjecture.

The super-efficiency slack-based measure (SBM) model considering the unexpected output was used to calculate the atmospheric environmental efficiency of 16 cities in Anhui province based on the panel datas of input and output of Anhui province from 2010 to 2018. And STATA software was used to analyze the internal elements of improving atmospheric environment. Empirical results show that the atmospheric environmental efficiency of Anhui province is generally low and presents the characteristic of “central Anhui > southern Anhui > northern Anhui”. It is beneficial to reduce the production of air pollutants to increase the investment of industrial R&D and the operation cost of waste gas treatment equipment, and the latter effect is more significant. Based on this, some suggestions on the input of atmospheric governance were given.

Tea culture tourism is an emerging form of rural eco-tourism. To clarify the main structure, basic knowledge framework, hot topics in different stages and overall development trend of tea culture tourism, with Citespace and VOSviewer as auxiliary tools of literature analysis, a visualized analysis of articles on tea culture tourism collected by China National Knowledge Infrastructure over the past 28 years from 1993 to 2021 was conducted, and the core authors and institutions, focus and the main development trend of researches in this field were summarized, so as to further the integration of tea culture and tourism by making relevant researches more standard and rigorous and enriching there searchers’ ideas.