In order to well know the current situation of atmospheric environment in Jilin City, correlation analysis method and applied statistical method were used to analyze the change characteristics of air pollutant mass concentration, and the correlation between pollutant concentration and meteorological factors, based on the monitoring data of CO, SO2, NO2, O3 (O3-8h), PM2.5 and PM10 from 7 ambient air quality monitoring stations in Jilin City from 2014 to 2018, and hourly meteorological data in 2018. The results show that: from 2014 to 2018, the annual average concentrations of SO2, NO2, PM10 and PM2.5 has showed a downward trend, while the concentration of O3 has been increasing in Jilin City, the concentrations of PM10, PM2.5 and O3 were occasionally higher than the national standard, indicating that they are the main air pollutants in Jilin City; the pollutant concentration varied from seasons, months and times, therefore, stagger production time according to the change law can improve ambient air quality; meteorological factors were correlative with pollutant concentrations, in which O3 concentrations was highly correlated with temperature, humidity and wind speed, and NO2 was highly negatively correlated with wind speed; the importance of meteorological factors to concentrations of CO, NO2, O3, PM10 and PM2.5 displays wind speed > atmospheric pressure > humidity > temperature; precipitation can reduce the concentration of PM10 and PM2.5, and the reduce effect was more obvious with increasing precipitation. The results of the current study can provide the data support for a further study of air pollution control and environmental capacity in Jilin City.

Cellulose is one of the most important renewable resources in nature. In this paper, a strain j-n3 was isolated from the soil of corn field. The isolated medium with carboxymethyl cellulose as the sole carbon source and Congo red staining method were used for preliminary screening, and then the screened strains were cultured by liquid fermentation and enzyme activity was determined. Combined with morphological characteristics and molecular biological identification, strain j-n3 was identified as Bacillus.According to the preliminary study of enzymatic properties, the optimum pH of the enzyme is 6.0, and the optimum reaction temperature is 50℃. After treated with strain J-N3 for 20 days, the weight loss rate and cellulose decomposition rate of corn stalks reached 26.22% and 31.01%, respectively.

The big data technology course is a core course in computer science that is interdisciplinary, practical, and cutting-edge. In response to the goals and requirements of cultivating innovation and entrepreneurship abilities, the characteristics and teaching objectives of big data technology courses were analyzed, and the problems in traditional course content and teaching methods were explored.Optimization methods were presented for teaching resource libraries, teaching methods, and assessment methods, and effective integrated teaching models and methods for innovation and entrepreneurship were proposed.The teaching practice shows that the optimized teaching content and teaching method have better improved the teaching effect and enhanced the students' ability of innovation and entrepreneurship.

In the process of MAP formation, the influence and change of pH of solution were very obvious，and then, the effects of pH on MAP production, yield and crystal type were studied. In the range of pH8~11, with the formation of MAP crystals, the pH of the solution dropped sharply, and quickly dropped to about 7 after 8min of addition. However, when the pH increased to 12, the pH of the solution changed slowly, but the impurities in the precipitate increased significantly, and basically no MAP crystal was formed. The results of yield experiment show that pH10 was the best condition for MAP production, which yield was high to 2.52g, and the impurities in the precipitate are few, the component was mainly magnesium ammonium phosphate. The SEM and XRD analyses showed that the composition of the precipitate were different with pH. It was mainly magnesium ammonium phosphate at pH8~10, however, the compositions of the precipitates were more complex at pH11~12, which were mainly the mixture of magnesium phosphate, magnesium hydroxide and ammonium magnesium phosphate. These results showed that the pH of solution has a significant effect on the formation of magnesium ammonium phosphate crystals.

The ideological and political courses can achieve quality improvement and efficiency by building golden courses, which is to meet the training needs of socialist builders and successors as well as the needs of individual students' development. In 2022, General Secretary Xi Jinping defined the effectiveness of ideological and political golden courses as "communication between minds, enlightenment of the mind and nourishment of the soul, inspiration of the fighting spirit". To explore three paths of realizing the effectiveness of ideological and political golden courses in colleges and universities from the perspective of Maslow's hierarchy of needs theory is a new idea for the construction of ideological and political courses in the new era.

A high-order ADRC scheme was proposed to deal with the unknown disturbance as well as the friction between the plate and the ball which affect the trajectory tracking accuracy in the ball and plate system. Firstly, the mathematical model of the ball and plate system was established and linear model was obtained by appropriately simplifying, linearization and decoupling. Secondly, the input signal with noise was filtered by the whole process fast differentiator. Thirdly, the high order ESO was designed to estimate the unknown disturbance inside the system. Finally, the nonlinear feedback controller was designed based on backstepping technique and the closed-loop stability is certificated by Lyapunov stability theory. Simulation results show that the improved high order ADRC can effectively filter out the noise and improve the trajectory tracking accuracy.

With the acceleration of globalization, supply chain has gradually extended from the coordination between internal and external enterprises at the micro level to the promotion of industrial chain and value chain at the macro level, and even the improvement of the performance of the whole national economy. Chemical industry is one of the five pillar industries in Jilin Province, but its industrial advantage has been weakening in recent years. From the perspective of modern supply chain, the paper found the problems in the development of chemical industry supply chain in Jilin Province, and tried to put forward the integration path and innovative development suggestions for the chemical industry supply chain in Jilin Province, so as to provide strategic reference for the realization of value chain climbing in the new development pattern of chemical industry in Jilin Province.

In the " Internet +" and the era of big data， combined the panoramic image technology with the
students＇ real life，and introduced design and implement the Internet +720° panoramic image display platform
concept and put into practice， which not only is a test to the students ＇ innovative entrepreneurial practice
ability，but also to improve the students＇ quality of innovation and entrepreneurship．It is a certain extent also
provides rich innovative and entrepreneurial practice inside and outside the schools．Furthermore，in this way，it
accumulates the experiences．

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.

The online teaching in ideological and political theory courses of colleges had come into a new condition under the epidemic prevention and control. It brings some new challenges in the implement of students' education. In order to meet the requirements of implementing the spirits of the important speeches by General Secretary Xi jinping and serve the high-quality development of higher education of "The Fourteen's Five-year Plan", it is necessary for colleges and universities to focus on the emotional education and gives deep consideration from  the following four aspects: leadership and management, purposes and tasks, objects of education and discipline integration in the subject of ideological and political education so as to improve the college students' sense of gain.