柳州职业技术学院

The self-piercing riveting is a major mechanical joining technique to join dissimilar lightweight materials, which has been widely used in the automotive industry. However, the die-casting aluminum sheet under the self-piercing riveted joint will generate cracks on the joint button due to the low ductility of the die-casting aluminum. A new technique of local-thickened self-piercing riveting (LT-SPR) is proposed to solve the problem of cracking on joint buttons in this paper. The effect of process parameters on cracking on joint button are discussed systematically and experimentally. The joint quality, mechanical properties, and failure mode of the LT-SPR joints are studied compared to the conventional SPR (C-SPR) joints. It is concluded that crack-free joints can be obtained in a wide range of rivet-die combinations using LT-SPR. Compared with the C-SPR joints, LT-SPR joints have larger forming quality indexes, smaller riveting force, smaller bending deformation, and better mechanical properties. For the LT-SPR process, the mechanical properties and failure mode are highly dependent on the rivet length, and larger rivet length can cause rivet fracture failure in the LT-SPR. The energy absorption of the joints that failed in interlock failure is superior to that of joints with rivet fracture failure, and joint strength is not affected by rivet fracture failure.

The business model is an effective and well-structured management tool that helps organizations acquire and hold onto a competitive edge over their competitors. This paper proposes a framework called “The Product Lifetime Value Business Model” for business model design and innovation of electric vehicle company. The framework consists of four layers, the innermost layer represents the business model, followed by the Product Lifetime Value layer and 6V model, the outermost layer comprises 17 additional dimensions that provide a more detailed and in-depth analysis. The concept of Product Lifetime Value is proposed and can be categorized into six distinct stages: planning, production, delivery, revenue generation, application, and recycling in this paper. In addition, a "6V" model is also proposed based on electric vehicle industry which contains value proposition, value creation, value delivery, value capture, value of after-sales services, and value of residual.

Objective:This study aimed to explore the aroma differences of Pixian bean paste from different brands and establish an analytical method for quality evaluation and quality control methods in Douban Sauce,based on solid-phase microextraction(SPME)and gas chromatography-mass spectrometry(GC-MS)techniques along with sensory evaluation.Methods:Three different brands of Pixian Douban Sauce were selected as the research objects.SPME and GC-MS techniques were used to extract and qualitatively analyze the aroma components,and the sensory evaluation of the three types of Pixian Douban Sauce was conducted based on current effective group standards.Results:57,90,and 70 volatile flavor compounds were identified in brands T,J,and C Pixian Douban Sauce,and 46,70,and 60 were identified in the database.Excluding impurity peaks and extremely low content fragment peaks,the flavor substances of brands T,J,and C are 32,47,and 43,respectively.Brand J has the highest sensory rating,followed by brand T,and brand C has the lowest.Based on the analysis of aroma components and content,the relative content of 3-methylbutyraldehyde and 2-methylbutyraldehyde(both with apple aroma and a pleasant feeling)in brand J is higher than the other two brands,and only furfural with a relative content greater than 3％ was detected in brand C.Conclusion:The combination of SPME-GC-MS technology and sensory evaluation analysis can distinguish the aroma components of different brands of Pixian Douban Sauce.

Phytosterols are 3-hydroxyl compounds with cyclopentadienanthrene as the backbone,which mainly exist in plant cell membranes in three forms:Free,esterified and glycoside.Phytosterols are precursors to the synthesis of steroid,vitamin D and many kinds of hormones.They are widely found in plant oils,vegetables,fruits,nuts,legumes and tubers.Phytosterols mainly include β-sitosterol,stigmosterol,canola sterol and so on,which are active substances with cholesterol structure.Phytosterols have many biological functions,such as regulating immunity,lowering cholesterol,anti-inflammatory,antioxidant,promoting growth,preventing cardiovascular and cerebrovascular diseases.With the deepening of research on phytosterols,they have been widely used in animal breeding and production in recent years.Phytosterols can improve the antioxidant capacity and immunity of animal body,improve lipid metabolism,improve production performance,improve the quality of animal products,and increase the economic benefit of breeding.In order to better apply phytosterols in animal production,the physicochemical properties,active functions and the research progress of phytosterols in animal culture were reviewed in this paper,and some references were provided for their further promotion and application in animal production.

Ganoderma lucidum has anti-tumor, antioxidant, and immune enhancing effects. This review summarized the latest research progress on the main nutritional components and biological activities of G. lucidum and the current comprehensive utilization status of G. lucidum in medical and health fields, analyzed the existing problems, and prospected the future development direction of G. lucidum.