Pingping Liu

In this work, FLUENT is used to systematically investigate the effects of two key factors on the hydrothermal performance and entropy generation within a mass flow rate range of 0.3–1.1 g/s: (1) the coupling modes between grooves (simple and composite) and microchannels (straight, convergent, and divergent), and (2) the cross-sectional shape of composite grooves. Results show that, compared with simple grooves, composite grooves induce stronger spiral fluid disturbances between the mainstream and near-wall zones, enhancing direct fluid impingement on groove walls and thus improving the cooling effect on the microchannel. Among the configurations, the coupling of composite grooves and converging microchannels (CG-R-CM) yields the highest Nusselt number (Nu = 2.38) and the lowest entropy production (SG = 0.0015) at a mass flow rate of 1.1 g/s, albeit with an exponential increase in pressure drop. In contrast, coupling of composite grooves with divergent microchannels (CG-R-DM) effectively reduces pressure drop, achieving a maximum hydrothermal performance (η) of 1.485. Furthermore, modifying the cross-sectional shape of composite grooves significantly improves heat transfer performance with only a slight increase in the pressure drop. The study provides design references for microchannel-composite groove coupling.

A phosphorus (P) and boron (B) enhanced N-doped carbon nanofiber material was prepared via a facile electrospinning method as a binder-free anode for lithium-ion storage application, achieving a high capacity retention of 94.8% after 500 cycles.

The hot-press fusing process of a laser printer is one of the principal causes for paper folding and bending deformation. In order to predict and control the deformation of paper, first, the following analysis method is proposed for the transient temperature field analysis of the continuous moving paper: discretizing the thermal analysis process, replacing the moving paper model with the moving heat source, and simulating the movement speed of paper by setting the flow boundary conditions. Second, taking the steady-state thermal calculation results of the printer in the standby mode as initial conditions, the temperature distribution characteristics of paper during the movement are obtained with the paper model placed in a whole-machine environment to analyze the transient temperature field. Third, using the method of multi-field coupling, the transient temperature field results of paper are taken as the external load of its static analysis to analyze the deformation of paper during the fusing process; therefore, the quantitative deformation results and deformation characteristics of paper after fusing are obtained. According to the results, more precise boundary conditions can be achieved by calculating the temperature field of paper in a whole-machine environment. The method of transient temperature field analysis for continuous moving objects proposed in this study can effectively simulate the movement process of paper. The results reveal the mechanism of paper wrinkle and bending deformation in the fusing process, which can be used to predict the conveying performance of paper and guide the design work of the printer.

Laser printer internal parts are prone to deformation when they are working in high temperature environment for a long time, resulting in machine faults such as paper jam and angle folding. In order to predict the deformation of parts in thermal environment and further determine their initial allowable deformation, so as to guide the structural design and production process of parts, and to reasonably determine the stress mode of parts in the working process, the structural deformation of the complex injection part-fuser upper cover in a laser printer after long-term operation in thermal environment is studied. First, on the basis of fusing temperature control technology and heat exchange analysis of the whole machine, the internal temperature field of a laser printer is numerically simulated by using the flow and heat transfer analysis software, and the temperature data of the key parts inside the machine are obtained more accurately. Then, the sequential coupling method is used to apply the results of thermal analysis of the whole machine as the external loads of static stress analysis to the fuser upper cover model, and the structural thermal deformation data of the fuser upper cover are obtained.

Current industrial robotics technology is often not well integrated with the enterprise’s on-site environment and actual working conditions and small and medium-sized enterprises are unable to achieve product automation due to production cost constraints. In order to meet the medium and small scale production of the slide valve body of OCV (Oil Control Valve) of a certain enterprise and its special process requirements, the automatic test system and sorting system based on the production environment of the enterprise are studied and designed. Firstly, according to the production conditions and process requirements of the enterprise, the overall design scheme of the automatic production line is put forward based on the existing automatic assembly system. Secondly, the test description is further improved by analysing and interpreting the test requirements of the products in detail and the automatic test system and test process are designed. Finally, according to the sorting process requirements, a Cartesian coordinate robot sorting system with two-terminal manipulators parallel operation is designed and its sorting motion scheme is optimized. The automatic test system and sorting system are seamlessly connected with the automatic assembly system, which can efficiently complete the automatic test and sorting of products and meet the production cycle time.

Firstly, the paper chooses one college as a case for analysis on self- cognition and career planning of college's students. And then, the paper analyzes the problems of career planning. And finally, from the following points such as adjusting the attitude to actively cope with employment pressure, a comprehensive analysis of college students to strengthen career planning awareness, and self - employed to innovate career planning to strengthen college's students career planning.

At present, there are three modes studying on the relationship between strategic human resource management and organizational performance. These modes are universality mode, form mode and contingency mode. The paper firstly analyses on the characteristics of these three modes. And then, it infers the need for the use of contingency mode studying on the relationship between strategic human resource management and organizational performance. Secondly, it measures the standard of the organizational performance. At last, the paper takes the qualitative research method to study on the relationship between strategic human resource management and organizational performance, what factors influence on the relationship between the two, and the mediating variables and how to influence the process. It tries to provide a basis for subsequent research.

Firstly, the paper analysis on the current situation of career planning and its problems, and then it selects one college as a case for analysis on self-cognition and career planning of college's students.And finally, from the following points such as planning and career planning curriculum, establishing career planning experiment center, improving service system and working mechanism, independent entrepreneurship and innovating career planning, it proposes strategy to strengthen the college students career planning.