With increasingly severe issues of energy crisis and greenhouse effect, countries are paying more attention to energy consumption and emission levels of agricultural machinery．Electrification and hybrid power technology, as important technical means to solve this problem, have gradually become a key research direction．Based on basic principles and different layout forms of agricultural machinery electrification and hybrid technology, research and application status of hybrid agricultural machinery were analyzed and summarized．Focusing on advantages, disadvantages, and key technological paths of hybrid technology, application methods and development points of hybrid technology in the field of agricultural machinery were discussed．Through evaluation and analysis of technological development and economic aspects, future research focus and development trend of hybrid agricultural machinery have been identified．

Due to poor working conditions and other reasons, diesel engine used in self-propelled intelligent flower leaf industrial hemp harvesting equipment（hereinafter referred to as hemp diesel engine）often experiences one type or another of malfunction, among which holding bush is one of the most common and serious faults in hemp diesel engines．Starting with analyzing stress on crankshaft bearing shells of diesel engines, a diagnostic approach for bearing shells was proposed based on working principle of diesel engine lubrication system and fault phenomenon of bearing shells．Specific reasons for bearing shells were analyzed in detail, and effective measures were provided to prevent and reduce bearing shells．And it creatively proposed adding a set of oil advance lubrication device to original lubrication system of hemp diesel engines, fundamentally avoiding occurrence of bearing failure．

Low level of mechanization and automation in facility agriculture seriously restrict development of facility agriculture in China．Affected by facility structure, natural conditions（light, ventilation, etc.）, planting habits and other factors, most of solar greenhouses in Shanxi Province are mostly about 20 m in the north-south ridge span, and north-south short ridge cultivation is not suitable for mechanized production operations, which seriously restricts improvement of mechanization level of facility agriculture．In 2022, Shanxi Agricultural Machinery Development Center and China Agricultural University conducted an experiment on tomato production in Qixian County and Xinjiang County of Shanxi Province, aiming to find a production mode suitable for machine-oriented cultivation of facilities in Shanxi Province．In the experiment, benefits of east-west ridge to high ridge cultivation mode and artificial north-south ridge to tomato production were compared and analyzed．The east-west ridge to mechanized tomato production could not only save labor and time to a great extent, but also have strong seedling, wide leaves, high fruit hanging rate and no reduction in yield．

In order to accurately grasp planting and production capacity of facility vegetables in Beijing City, and to deeply explore value of 5000facility greenhouse data collected by the "digital vegetable field project", research on facility production status and crop variety recognition based on internet of things technology and image recognition technology was carried out．A facility greenhouse production status recognition model and a crop variety recognition model was constructed, which have been integrated into Beijing crop industry comprehensive management platform, and thus a regulatory facility agriculture application scenario was constructed, so as to provide precise and efficient centralized supervision, remote command, and decision-making support for government, and promote revitalization of agricultural industry and rural areas through development of facility vegetables in Beijing City．

In view of low efficiency, high cost and large pollution of pesticide spraying in corn seedling stage, a visual recognition and spraying system that can be mounted on a small pesticide spraying robot was proposed．The system used SSD-MobileNetv1 network as corn seedling recognition algorithm, combining methods of data augmentation and transfer learning．The ARM was used as an embedded device．When camera detected corn seedlings within spraying range, control pin generated PWM signals to start praying system to spray accurately．Results showed that recognition accuracy of system for corn seedlings could reach 84.18%, and estimation of distance basically met requirements of robot spraying．

In order to improve comprehensive management level of agricultural mechanization in Beijing City, achieve scientific monitoring and evaluation of agricultural machinery operation quality, and support scientific distribution of subsidies for protective tillage operations, the Beijing agricultural machinery big data platform has been developed．This platform included five modules: agricultural mechanization comprehensive exhibition, cooperative management, agricultural machinery management, precision operation management, and subsidy operation supervision．From 2020 to 2022, 749 sets of monitoring terminals for conservation tillage operations were installed．Centering on three operation links of deep loosening, straw returning to field and less and no-tillage seeding, this platform collected equipment and operation information from 101 cooperatives and 29 agricultural machinery households, with a total operating area of 83000 hectares and a total of 25685 operating plots．Monitoring area accounted for 71.51% of total planned area reported by each district, supporting distribution of agricultural machinery operation subsidies of 6042.31 million yuan in 9 agricultural districts in Beijing City．

The Xinjiang cotton meteorological data service platform was established by meteorological site live database, meteorological grid database, meteorological early warning database, historical meteorological database, farmland microclimate site database, service product database, and cotton climate suitability evaluation database, to achieve cotton monitoring and forecasting, disaster warning, climate charts, cotton technical services, my cotton five functions, and carry out location-based grid real-time data, query of forecast and early warning data, statistics of historical meteorological data and refined meteorology serve agricultural service products．The purpose was to promote precise, personalized, and digital development of cotton meteorological services in Xinjiang, and to improve level of cotton meteorological services in Xinjiang．

In order to promote development of blueberry industry, climate resources in Dandong City, Liaoning Province, were investigated and analyzed in 2022．Results showed that climate resources of temperature, light and water in main blueberry producing areas of Dandong City were abundant, and climate conditions for blueberry growth were satisfied, combination of region's geographical location, natural environment, technical conditions, investment costs and other advantages, it was very conducive to development of blueberry industry．But at the same time, because of special geographical environment of border, coast and river, meteorological disasters such as strong wind, hail and even rain occur more frequently, which have a certain impact on characteristic agriculture of blueberry, in particular, hail weather disasters are most serious in fruit period of blueberry flower, it could lead to no harvest and no yield, and weather disasters of strong wind and even rain are relatively light．According to law of weather disasters, defense suggestions were put forward, according to characteristics of climate conditions in this area, suggestions and measures to promote development of blueberry industry were put forward．

Based on environmental impact and resource consumption, a comprehensive evaluation model for life cycle of direct combustion power generation system of pruned apple tree branches was established and analyzed．Results showed that comprehensive performance index of direct combustion power generation of pruned apple tree branches ranged from 0.055 to 0.225(person·year)/(10000 kW·h), and effect of environmental impact on comprehensive performance was much greater than that of resource consumption, and characteristics were local > equal > regional > global．The maximum value of direct combustion power generation of pruned apple tree branches was only 57.25% of the minimum value of coal-fired power generation, showing a good advantage．Comprehensive performance of direct combustion power generation of pruned apple tree branches was most sensitive to total amount of solid waste and raw material consumption rate．Therefore, effective management and disposal of solid waste, as well as improvement of quality of biomass boilers and fuels, can further improve environmental benefits of direct combustion power generation of pruned apple tree branches．Results of this study could provide theoretical basis and reference data for research of direct combustion power generation system based on pruned fruit tree branches．

Core material is one of the key materials of wind turbine blades, which is mainly used in shell, web and blade root of wind turbine blades．The core materials mainly provide stiffness and shear resistance for blades, so core materials need good mechanical properties and mechnial properties．For the foam core materials currently used in wind turbine blades, domestic and foreign research institutions and manufacturers have been carried out many studies．The progress of four widely used wind turbine blade core materials（Balsa, PVC, PET, and SAN）in performance and processing application was reviewed．

According to process requirements of rice drying, taking air source heat pump grain dryer of a family farm in Taizhou City as an example, performance of air source heat pump hot air unit based on internet of things was tested and studied under different ambient temperatures and matching different dryer conditions．Data such as temperature, air volume and power consumption of hot air dryer were collected．Actual performance of heat pump system was analyzed by calculating data of heat production, coefficient of performance（COP）, specific moisture extraction rate（SMER）and drying cost．Results showed that performance of air source heat pump system was significantly affected by average ambient temperature．With increase of ambient temperature, heat produced by heat pump gradually decreased, COP increased and SMER increased．However, when ambient temperature was lower than 9 °C, outlet air temperature of heat pump could not reach set value, COP and SMER were lower than mean value．The system performed well when ambient temperature was higher than 9 °C．

A fragrant pear brown yogurt with a burnt and pear aroma was prepared using fragrant pears, skimmed milk, and white granulated sugar as main raw materials, and a mixture of Streptococcus thermophilus and Lactobacillus bulgaricus as fermentation agent．Using acidity, viscosity, pH value, and sensory evaluation as indicators, optimal processing technology was selected through single factor experiments and response surface methodology．Through experimental analysis, it was found that optimal process for producing fragrant pear brown yogurt was as follows: adding 8% fragrant pear juice, 4 % white sugar, 0.30 % fermentation agent, 7 hours of fermentation time, and 43 °C fermentation temperature．Under these conditions, fragrant pear brown yogurt has a scorched and pear aroma, the best taste．

The aim of this study was to explore appropriate density and time for waterless live transportation of Urechis unicinctus．Physiological stress and quality indicators of samples in control group, low-density group, medium-density group and high-density group were analyzed at different transport time．Results showed that concentration of cortisol in three density groups was significantly higher than that in control group（P<0.05）．Water holding capacity and lactic acid contents changed significantly after treatment of 24 h（P<0.05）．Transportation density stress had a greater effect on glucose content．Glucose content in high-density group was significantly higher than other two density groups at 12 to 60 h（P<0.05）．There was no significant difference in SOD activities between different densities at 36 h and 60 h, and change of malondialdehyde showed the same trend（P>0.05）．Recommended transport density should not exceed 1.0 kg/L during waterless live transportation to better maintain quality of Urechis unicinctus．

Shortage of water resources is main problem facing agricultural production in northern China．Current agricultural irrigation（amount and time）in this region mostly depends on manual control, which not only wastes water resources but also threatens crop growth．Promoting agricultural intelligent irrigation technology is an effective way to achieve intelligence and scientificization of agricultural irrigation and improve efficiency of water resource utilization．Development status and existing problems of intelligent irrigation in water shortage region of northern China were summarized．A variety of farmland intelligent irrigation technologies and their applications in different types of crop land were listed．Suggestions and prospects for developing intelligent irrigation were put forward, expecting to provide a reference for application of agricultural intelligent irrigation in northern China．

Aiming at problems of high energy consumption, easy adhesion and poor reliability of turning plow, high-speed intelligent hydraulic turning plough was developed, and structure and configuration parameters of whole machine were optimized．Bionic plough was designed by combining triangular arc structure of pangolin's body surface with convex hull structure of dung beetle's body surface as a bionic prototype．Overload protection automatic obstacle avoidance mechanism of two-way ploughing equipment was designed．In equilibrium state, required spring pre tension force was 9.75 kN, with a safety factor of 1.3, and initial pre tension force was set to 12.67 kN．Discrete element simulation model of ploughing process was established．Compared with traditional plow, soil viscosity reducing performance of bionic plow body is increased by 44.15% and drag was reduced by 7.8%．Coefficient of variation of tillage depth stability was 2.86%, and broken rate of soil was 97.1%．It could provide reference for design and improvement of high-speed intelligent hydraulic turning plow．

Various components of combine harvester are connected by bolts and their connectors, which affect and excite each other during working process, and have severe impacts, wear, and unbalanced collisions．Degree of looseness and main vibration at bolt connections was studied, time-domain characteristics of main working components of combine harvester during working process were extracted, and main frequency and harmonics response of bolts and their connections were analyzed．Results indicated that during normal operation, time-domain characteristic values of edge bolts of vibrating screen were at extremely high levels, and frequency components were also relatively complex．Main frequency of other measurement points was 34.7195 Hz, and there was no obvious sideband generated in frequency doubling．However, vibration screen bolts were not affected by engine rotation frequency and its doubling frequency, except for their own main frequency of 2.302 Hz and its high doubling frequency．It could be concluded that bolt connection of vibrating screen was subjected to the most severe and complex load, laying foundation for online monitoring of bolt and connector loosening and failure at vibrating screen．

In order to address issues of excessive spray boom in large-scale high clearance sprayer and poor damping effect of vibration damping elements, using test method of quadratic orthogonal rotation combination, field vibration tests with four factors and three levels were carried out on suspension damping elements, and significance and trend of each factor's influence on vibration were obtained．Parameters of vibration damping combinations were optimized and experimentally validated．The optimal vibration damping combination was found to be a sprayer travel speed of 2.125 m/s, a vertical spring stiffness coefficient of 78.14 N/mm, a vertical damper restoring damping coefficient of 8.23 N·s/mm, and a horizontal damper restoring damping coefficient of 8.74 N·s/mm．After optimization, percentage of acceleration within the range of 0～6 m/s² in the boom's direction of travel accounted for 85.26%, which was increased by more than 4%．Percentage within range of 0～0.6° for roll angle accounted for 88.37%, which was increased by more than 4%．And percentage within range of 0～6 m/s² for vertical direction acceleration accounted for 87.96%, which was increased by more than 3%．Combination testing and optimization validation of boom suspension vibration damping elements could provide valuable references for setting operational parameters and selecting damping element parameters for sprayers．

When tunnel type food fryer is running, deformation of tank body when it is heated will affect operation stability of fryer．The maximum deformation of traditional "U" shaped tank has reached 20 mm, resulting in frequent failures of transportation, slag removal and other mechanisms, which has been plaguing equipment manufacturers．Thermal deformation of tank body of buffer tank structure fryer is small．Due to defects such as incomplete slag removal and inconvenient cleaning, it is not conducive to widespread promotion．The minimum thermal deformation of tank body of the "H" shaped tank structure frying machine could be controlled below 6 mm．Under this deformation, operation stability of whole machine can be improved, and it is not difficult to process．This technology can be promoted and applied in tunnel type food fryer．

To understand hotspots and trends of carbon emission in China in recent 20 years, literatures about carbon emission research in China in recent 20 years were analyzed based on knowledge graph, which quantity was 5683, and authors, published organizations, literatures influence, factors affecting carbon emissions, results of carbon emission reduction, measures to reduce carbon emission and future research trends in carbon emission reduction were analyzed．Results showed that network of researchers involved in carbon emissions was closely connected and showed a certain special block．Research institutions were mainly composed of high-level and interconnected research institutions, which plaied a positive role in promoting carbon emission research．Research focus on carbon emissions was factors of carbon emission, impact of excessive carbon emission, measures to reduce carbon emissions．High-impact literature was mainly based on data analysis, among which the most frequently cited literature was cited 17029 times．Researches on impact of carbon emissions mainly focused on three aspects: climate change, agricultural development and economic development．Through development of a low carbon economy and policy lead to reduce carbon emissions．In the future, main fields of carbon emission research still included economy and ecology, in addition, carbon neutrality and emission peak would become a relatively concentrated hot topic．Results could provide a reference for future scholars in this field．

In order to improve training quality of graduate students majoring in mechanical engineering and cultivate innovative and application-oriented high-quality talents, teaching reform of course of Engineering Optimization Design Methods was carried out．Significance of constructing a case base was explained, and teaching of this case base was analyzed mainly from aspects of its construction content, implementation methods, and implementation effects．A large amount of tedious theoretical knowledge was transformed into rich engineering practice cases．Teaching practice of case base in the past three years has shown that this method not only improved classroom teaching effectiveness and promoted deep cooperation between schools and enterprises, but also enhanced teaching ability of teachers．

Perfect practice teaching is objective requirement for cultivating application-oriented talents in colleges and universities, and school-enterprise collaborative teaching is an important way to cultivate high-level applied talents．Significance, current situation, and shortcomings of school enterprise cooperation practical teaching mode in bioengineering major in higher education institutions was analyzed．From perspective of mutual development among students, schools, and enterprises, teaching reform ideas were proposed to promote rational development of applied talent cultivation in bioengineering major．

Importance and necessity of combining professional courses with ideological and political education was systematically introduced．Focused on ideological and political elements contained in Food Microbiology and organically integrated some typical cases with knowledge points in the course．It was expounded how to realize high efficiency of ideological and political construction of curriculum from aspects of reforming teaching methods, innovating teaching concepts and improving ideological and political awareness of teachers．It could provide reference for ideological and political construction in subsequent professional courses, and provide reference and inspiration for teachers to explore ideological and political elements from knowledge points of professional courses．

In order to understand relative importance of main agronomic traits in yield composition of maize in Anhui Province, relationship and evolution between yield and main agronomic traits of maize varieties tested in high density group of regional experiment in Anhui Province from 2011 to 2021 were analyzed by correlation analysis and path analysis．Results showed that output level of testing varieties in Anhui Province rised steadily, evolution trend of number of rows per ear, number of grains per row, ear length, and seed yield was consistent with yield, which had a significant direct impact on yield．Growth period, plant height, spike height, spike diameter, bald tip length, empty stem rate, and lodging（folding）rate showed a downward trend, which was also directly related to continuous improvement of yield．Correlation coefficients between characters and yield were panicle diameter > row grain number > panicle length > seed-producing rate > 1000-grain weight > panicle position height > growth period > plant height > panicle row number > lodging rate > empty stem rate > bare tip length, and panicle diameter, row grain number, panicle length, seed-producing rate and yield were significantly positively correlated．The 1000-grain weight, panicle height, growth period and plant height had no significant correlation with yield, while number of panicle rows, empty stem rate, lodging rate and bare tip length had negative correlation with yield．It was found that panicle diameter, grain number per row, panicle length, seed-producing rate and 1000-grain weight were highly correlated with yield of 550 varieties, but row number per ear was not highly correlated with yield．

In order to verify effects of multi-year mixed application of biogas slurry and mushroom residue on yield and quality of tomato and soil environment in solar greenhouse, a single variable method was used to take "Provence" tomato as test material．The yield, quality and soil physiochemical properties of tomato under four treatments of conventional fertilization（CK）, biogas slurry returning to field（BS）, oyster mushroom residue returning to field（MR）and combined application of biogas slurry and mushroom residue（BM）were studied．Compared with CK, BS, MR and BM treatments, yield and soluble sugar content of tomato were increased by 19.33%, 14.32% and 31.49%, respectively．Contents of soil organic matter, available nitrogen, available phosphorus and available potassium were increased, and soil environment of tomato planting was improved．Diversity of fungi community was increased, and diversity of archaea and fungi community was decreased．BS or BM treatment could not only increase tomato yield, but also to some extent improve basic physical and chemical properties of soil, change microbial community structure in tomato rhizosphere soil, and promote crop nutrient absorption and utilization．

Apricot is an important variety of forestry and fruit industry in Xinjiang Production and Construction Corps（XPCC）．Based on ecological suitability evaluation, comparative advantage analysis and cost benefit on market demand analysis of apricot, comprehensive evaluation of apricot planting layout of XPCC was carried out．Research results indicated that excellent planting areas for apricots were concentrated in key production areas such as the First, Third, and Fourth Agricultural Divisions．Evaluation results were consistent with overall production situation, providing quantifiable reference for optimizing apricot planting layout of Xinjiang Production and Construction Corps．

Taking Homey Group as an example, industrial chain of it and relationship between brand construction of marine ranching and its industrial chain was analyzed．Brand cultivation path of Homey Group was elaborated, which included group's marketing network and means adopted in marketing process．Based on perspective of industrial chain, a brand building model for ocean ranches was constructed, which should require precise brand positioning, ensure safety and green of entire industry chain, search for unique product innovation points, and deeply expand brand marketing channels, in order to provide useful reference for sustainable development of ocean ranches in China．

Ecological agriculture is an effective way to realize dual goals of ecological revitalization and agricultural revitalization．Vigorously developing ecological agriculture is a scientific practice of ecological civilization thought of "harmonious coexistence between humans and nature"．Taking Zhongzhong Village in Ankang City, Shaanxi Province, Qinba Mountain Area as an empirical case, using a combination of literature research and market research methods, "three main bodies, three links, and three livelihoods" ecological agriculture revitalization model, main practices, and experience inspirations of Zhongzhong Village were summarized and analyzed, and development suggestions were proposed, intended to provide examples and reference for development of ecological agriculture and promotion of rural industrial revitalization in the Qinba Mountains or similar areas．

To study current development status of Laiyang pear industry, diamond model was used to analyze advantages of industrial clusters．It was found that pear industry in Laiyang City has obvious advantages, but there were still problems such as aging of pear farmers, low degree of production and operation coordination, and insufficient excavation of cultural heritage．Through analysis of coupling and coordination relationship between culture, tourism industry, and regional economy in Laiyang City, it was shown that development of cultural industry in Laiyang City was relatively lagging behind, and there was an urgent need to accelerate integration of pear industry and cultural tourism industry．Measures were proposed using a three-dimensional dynamic model to enhance comprehensive competitiveness of Laiyang pear industry．