山东华宇工学院是经教育部批准设立的一所全日制普通本科高校，坐落于素有“九达天衢、神京门户”之美誉的山东省德州市，位于德州市德城区古运河畔锦绣川风景区附近。学校的前身是创建于2002年的德州华宇学校；2004年改建为专科层次的山东华宇职业技术学院；2014年升格为全日制普通本科高校，更名为山东华宇工学院。2018年6月，山东省人民政府学位委员会批准学校列为学士学位授予单位。学校已建成省级品牌专业群1个，山东省民办高校本科优势特色专业4个，省级高职特色专业3个。学校坚持地方性、应用型、开放式的办学定位，适应山东经济社会发展，开设普通本科专业30个，高职（专科）专业35个，形成了以工学为主体，以管理学和艺术学为两翼，以能源和智能制造类专业为特色，工学、管理学、文学和艺术学多学科协调发展的学科专业格局。建筑环境与能源应用工程、机械设计制造及其自动化、电气工程及其自动化、数字媒体技术和电子信息工程为省级普通本科优势特色专业；其中，数字媒体技术和电气工程及其自动化获批省级一流特色专业建设点。
Effectively managing heat generation in high-power electronic devices and microelectromechanical systems is critical for their performance and reliability. This paper proposes and numerically optimizes an innovative microchannel heat sink (MCHS) design that incorporates 50 curved concave microchannels, each separated by a cylindrical microtube. The design aims to enhance heat transfer efficiency while addressing manufacturability. The MCHS, fabricated from copper, is cooled by a laminar, single-phase flow of a silver/water–ethylene glycol hybrid nanofluid (50:50), with nanoparticle volume fractions ( ϕ ) ranging from 0 to 1 ϕ = 1
This paper conducts a comprehensive investigation into the dynamic and damping characteristics of composite cylindrical shells incorporating multiple viscoelastic damping layers. A refined mathematical model is developed, specifically tailored for multilayer composite shell structures with embedded damping treatments. The formulation employs the first-order shear theory to establish the kinematic relationships and constitutive equations. The governing equations are systematically derived employing Hamilton’s principle, accounting for the viscoelastic material behavior through a complex modulus approach. The eigenvalue problem is solved analytically by the Navier solution technique, providing efficient computation of natural frequency (NF) and associated loss factor (LF) for simply-supported composite open cylindrical shells with varying numbers of damping layers. A comprehensive parametric investigation was performed to assess the effects of critical structural parameters. Important conclusions are drawn regarding the optimal design strategies for composite sandwich open cylindrical shells with integrated viscoelastic damping treatments, providing valuable guidance for practical engineering applications in aerospace and automotive industries requiring enhanced vibration control.
A cobalt-modulated NiCoMnCuFe high-entropy alloy anchored on reduced graphene oxide was rationally designed, delivering low Tafel slopes of 38.1 and 64.1 mV dec-1 for OER and HER, respectively. The catalyst enables alkaline overall water splitting at 1.80 V to reach 1 A cm-2 with stable operation over 50 h. Density functional theory (DFT) calculations reveal that Co-induced charge redistribution optimizes intermediate adsorption and accelerates reaction kinetics.
A novel microchannel integrated with zigzag cavities and waterdrop-shaped ribs was proposed in this study to enhance heat transfer. Numerical simulations were conducted to analyze the thermal-hydraulic performance of water in the novel microchannel, while the entropy generation principle was employed to elucidate the underlying mechanisms. Results show that: within a Reynolds number (Re) range of 341-796, compared with the straight microchannel (Structure-1), the zigzag microchannel (Structure-2), the straight microchannel with waterdrop-shaped ribs (Structure-3), the heated-surface average temperatures of the zigzag microchannel with waterdrop-shaped ribs (Structure-4) decreased by 24.1-30.1 K, 18.3-24.2 K, and 1.0-2.5 K, maximum temperature reduced by 33.3-39.7 K, 21.8-27.4 K, and 2.7-3.7 K, while the average Nusselt numbers (Nuave) exhibited maximum increments of 106.01%, 80.21%, 12.15%, respectively. At Re = 568, the pressure drop (Delta p) of Structure-3 increases nearly seven times compared with Structure-1, and 32.42% higher than Structure-4. Notably, Structure-4 outperforms in both heat transfer and flow resistance. For all the same Re, the entropy generation increase number (Ns,a) of Structure-4 is 16.9%-22.5% lower than Structure-3, indicating that a synergistic combination of zigzag cavities and waterdrop-shaped ribs is superior in reducing the irreversibility of flow and heat transfer. The flow resistance of Structure-4 was reduced by 50.08%-57.73% compared with Structure-1 in the study range. The results can clarify the differences in heat transfer and fluid flow among diverse structures, and provide a foundation for microchannel selection, optimal design, and heat transfer efficiency enhancement.
This study explores the psychological mechanism linking moral leadership to the work engagement of young university teachers. Drawing on Self-determination Theory, we tested a model where professional identity—comprising efficacy, belonging, and values—mediates this relationship. Using questionnaire data from 285 teachers analyzed with structural equation modeling, we found moral leadership significantly enhanced all three dimensions of professional identity. While professional efficacy and values positively predicted work engagement, professional belonging did not show a direct impact. Most importantly, the results confirmed a complete mediation: the direct influence of moral leadership on work engagement was non-significant, indicating its effect is entirely channeled through professional identity. This research reveals the core path through which moral leadership operates in higher education, confirming that satisfying teachers’ psychological needs via identity enhancement is key to fostering engagement, and providing clear implications for university management.
