On Energy Assessment of Titanium Alloys Belt Grinding Involving Abrasive Wear Effects

Improved energy utilisation,precision,and quality are critical in the current trend of low-carbon green manufactur-ing.In this study,three abrasive belts were prepared at various wear stages and characterised quantitatively.The effects of abrasive belt wear on the specific grinding energy partition were investigated by evaluating robotic belt grinding of titanium plates.A specific grinding energy model based on subdivided tangential forces of cutting and sliding was developed for investigating specific energy and energy utilisation coefficient EUC.The surface mor-phology and Abbott–Firestone curves of the belts were introduced to analyse the experimental findings from the per-spective of the micro cutting behaviour.The specific grinding energy increased with abrasive belt wear,especially when the belt was near the end of its life.Moreover,the belt wear could lead to a predominance change of sliding and chip formation energy.The highest EUC was observed in the middle of the belt life because of its retained sharp cutting edge and uniform distribution of the grit protrusion height.This study provides guidance for balancing the energy consumption and energy utilization efficiency of belt grinding.

Effect of Optimization of Agricultural Supply-side Factors on Characteristic Modern Agriculture--A Case Study of Chu Orange Manor

The structural imbalance of supply and demand of agricultural products is the result of agricultural products overemphasizing quantitative growth and neglecting quality improvement. The structural reform of agricultural supply side is to optimize the allocation of agricultural production factors,improve the quality and efficiency of supply,and meet the quality needs of consumers. The optimization of agricultural supply factors is the result of effective supply,rational allocation and comprehensive utilization of natural resources and social resources. The success of Chu Orange Manor has explained the function of the optimization of supply factors to the development of characteristic agriculture. That is,it has promoted the development of high-end agriculture,promoted the brand value of agricultural products,promoted the competitiveness of agriculture,broken the international green trade barrier of agricultural products,promoted the development of modern agriculture with characteristics,and realized the sustainable development of rural areas.

Strong room-temperature emission from defect states in CVD-grown WSe2 nanosheets

Monolayer transition metal dichalcogenides （TMDCs）, as direct bandgap semiconductors, show promise for applications in ultra-thin flexible optoelec- tronic devices. However, the optical properties and device performance are greatly affected by defects, such as vacancies, present in these materials. Vacancies exist unavoidably in mechanically exfoliated or grown by chemical vapor deposition （CVD） monolayer TMDCs; therefore, their influence on the electric and optical properties of host materials has been widely studied. Here, we report a new defect state located at 1.54 eV, which is 70 meV lower than the neutral exciton energy in as-prepared WSe2 monolayers grown by CVD. This defect state is clearly observed in photoluminescence （PL） and Raman spectra at ambient conditions. PL mapping, Rarnan mapping, and atomic force microscopy analysis indicate a solid-vapor reaction growth mechanism of the defect state formation. During a certain growth stage, nuclei with the composition of WOxSey do not fully react with the Se vapor, leading to the defect formation. This type of defects permits radiative recombination of bound neutral excitons, which can make the PL intensity as strong as the intrinsic excitation. Our findings reveal a new way to tailor the optical properties of two-dimensional TMDCs without any additional processes performed after growth.

Biomechanical study on implantable and interventional medical devices

Implants,including artificial joints,bone fixation devices,and other orthopedic implants,oral implants,and vascular interventional devices,are used to repair or replace human tissues or organs and restore their functions.Since biodegradable implants have advantage of avoiding long-term complications(including bone stress shielding,restenosis,thrombosis,and secondary surgery)while remaining safe and productive,personalized biodegradable implants will be an irresistible trend in the clinic for implantable and interventional medical devices.However,innovation of personalized biodegradable implants faces several challenges,including the interaction between the implant and its surrounding tissues or cells,the coordination of structural strength of implants and its degradation,the topological microstructure of implant and its fatigue properties,reliability,and safety.In this review,we introduced critical progresses achieved in the fields related to implants,including mechanical properties of materials,interaction between implants and host tissue,effect of stress on degradation;furthermore,we highlighted the optimized design and manufacture of implants as well as the evaluation of their reliability.