The development history and technical overview of HPPO process by direct oxidation of hydrogen peroxide are reviewed at home and abroad, including the technical features and process flow of Basf/Dow chemical, Evonik/Uhde company, Sinopec and Yida chemical. The mechanism of HPPO process,the conditions of side reaction, the choice of reaction solvent and the purification method of PO are analyzed in detail. Some key problems in HPPO production process are put forward.
The Chinese science fiction film The Wandering Earth has achieved great success in the foreign film market. From the perspective of "skopos theory" in translation, this paper attempts to discuss the strategies and shortcomings of subtitle translation with the help of the translation principles of purpose, coherence and fidelity, so as to provide some references for the subtitle translation of Chinese films.
At present, the development of the second-hand auto market is extremely rapid. According to statistics, from 2000 to 2017, the number of second-hand auto transactions rose from 251,700 to 12,409,900, an increase of 49 times. With the increase of the penetration rate and the average age of cars, the volume of used cars in China will continue to increase in the next five years at a rate that exceeds the trading volume of new cars, forming a two-trillion-yuan used car market pattern. With the further development of the domestic car market, the number of new vehicles has been increasing, and consumers are eager to change their cars. The urgent demand has become increasingly prominent. The prospects for the development of the used car market are very broad.
AGV is the key equipment for the flexible and intelligent modern logistics system. This paper mainly designs the system of magnetic navigation AGV, including structural design and control system. In the structural design, the differential steering six-wheel running mode is adopted, and the three-dimensional design software is used for the modeling design. The control system adopts the MCU as the control unit. Based on the magnetic navigation, the fuzzy control is used to realize the driving speed adjustment to ensure that the AGV runs on the predetermined trajectory, so that the AGV has strong stability, fast response speed and automatic correction in the work. Ability. Finally, the corrective ability of the AGV is verified by simulink simulation.
Alkaline phosphatase (ALP) exists widely in human body and controls the processes in various physiological organisms. At present, it has been widely used in clinical, biological, medical and other fields. As a key biomarker of many diseases and a major tool of enzyme experiments, the classical ALP analysis methods cannot meet the new requirements of sensitivity, accuracy, anti-interference and wide range of targeted sample types. In order to better study ALP detection technology, this paper describes a variety of extraction and detection methods, including the latest ALP detection technology at home and abroad. At the same time, we summarize and compare the main advantages and disadvantages of these studies. At the same time, the future development prospects and trends are discussed, hoping to provide some inspiration for future work.
The carbonylative coupling reactions of aryl halides are effective way to synthesize carbonyl compounds. There are more valuable to realize the carbonylative coupling by C-H unactivation. In recent years, transition metal-catalyzed carbonylative coupling reactions have attracted more attention. But more energy will be needed in the cleavage process of C-H and the demands of the structure of substrates and types of catalyst are very harsh. We summarize the advances in transition metal-catalyzed carbonylative coupling by C-H bond activation from the point of the types of catalyst.
Enucleation is a necessary procedure in the process of pre-treating hawthorns. At present manual enucleation is still the most widely used method in China. However, such a manual method requires high labor intensity and is usually poorly efficient, which can easily result in overstock and decomposition of hawthorns, and furthermore cause huge economic loss for farmers. To this end, research and design a fully automatic hawthorn kernal-removal equipment, and to produce a simplified version of the prototype, the experimental results show that the processing efficiency of the design equipment is 12 times the manual processing. Using SolidWorks to analyze cutting system, the key part of the fully automatic hawthorn kernal-removal machine. The results of the analysis show that the maximum stress of the cutting system is 127.5MPa and the maximum deformation is 0.225mm, both of which appear at the joint of the knife holder and the motor, which shows that the reliability of the equipment meets the requirements , For the design and optimization of similar products provide a reference.
The young people' establishment of cultural self-confidence is a requirement of the development of the new era, which bears the future and destiny of the country. The mainstream cultural consciousness of contemporary youth generally presents a positive, healthy and good form that conforms to the development requirements of the socialist era. However, there are still weak links in cultural cognition, cultural value pursuit and cultural safety awareness. To cultivate the cultural confidence of the young people, we need to build a solid foundation of cultural confidence among the society, schools and young people.
Artificial Intelligence, as a branch of computer science, has been applied and developed in education industry in recent years. Higher education is the main place for training talents in our country, and it is also one of the best application scenarios of artificial intelligence. Among them, image processing technology is becoming more and more mature. Face recognition access control has gradually entered people's lives. Integrating artificial intelligence face recognition with laboratory entrance guard, obtaining students'face information from university student database, uploading it to face database in batches, and combining the entrance guard system with the administration system, students can make experiment appointment, brush their faces into the door, and input attendance information into the educational administration system. The application of this system promotes the development of educational informationization and realizes University laboratory. Intelligent management.
吉林化工学院学报自然科学版模板 
