用于实时皮肤创面愈合的超强工程化蛋白凝聚体黏合剂

Adhesives have attracted a great deal of attention as an advanced modality in biomedical engineering because of their unique wound management behavior.However,it is a grand challenge for current adhesive systems to achieve robust adhesion due to their tenuous interfacial bonding strength.Moreover,the absence of dynamic adaptability in conventional chemical adhesives restricts neoblasts around the wound from migrating to the site,resulting in an inferior tissue-regeneration effect.Herein,an extracellular matrix-derived biocomposite adhesive with robust adhesion and a real-time skin healing effect is well-engineered.Liquid–liquid phase separation is well-harnessed to drive the assembly of the biocomposite adhesive,with the active involvement of supramolecular interactions between chimeric protein and natural DNA,leading to a robustly reinforced adhesion performance.The bioadhesive exhibits outstanding adhesion and sealing behaviors,with a sheared adhesion strength of approximately 18 MPa,outperforming its reported counterparts.Moreover,the engineered bioderived components endow this adhesive material with biocompatibility and exceptional biological functions including the promotion of cell proliferation and migration,such that the use of this material eventually yields real-time in situ skin regeneration.This work opens up novel avenues for functionalized bioadhesive engineering and biomedical translations.

汽车行业双积分政策和碳交易的衔接优化——双层规划模型

随着中国双碳战略的推进,越来越多的学者和专家呼吁将双积分政策转变为碳交易机制,以更好地发挥汽车行业在碳减排方面的潜力。然而,关于这两种政策之间的衔接时间问题,学术界存在不同的观点和争议。为此,本文构建了一个双层规划模型,以探究政府政策与汽车制造商的生产和研发决策之间的相互关系,并研究碳交易引入时间和碳配额的最佳决策。研究结果表明,考虑到碳价和积分之间的价格差异,目前并非最佳时机来衔接这两种政策。值得注意的是,新能源汽车和传统燃油汽车的单车碳排放量减少对于碳交易引入时间存在相反的影响。此外,通过比较新能源汽车的利润和碳价格对于碳交易引入时机的影响,我们发现前者对于汽车行业采用碳交易机制的影响更为显著。

结合以旧换新的预售策略

近来,预售和以旧换新项目在许多行业中越来越受欢迎,现有文献分别研究了这两种策略,但这两个策略相结合的情况还没有被研究过。受商业实践的启示,我们研究了一种新的预售策略(AT策略),该策略利用以旧换新作为参与预售的奖励或折扣。本研究分析了在分别采用AT策略、传统预售策略(AS策略)和传统以旧换新策略(TN策略)时卖家的定价决策和最佳利润。我们发现当旧产品的残值足够低且产品成本不是太小时,相对于AT策略,卖家选择AS策略更优。另外,相对于TN策略,当产品残值和产品成本较低时,卖家在大多数情况下应该采用AT策略。此外,我们证明了在AT策略中当产品价格极高时卖家仍旧是有利可图的。即使消费者在预售阶段的效用是负的,他们仍愿意参加预售,因为购买两代产品的总消费者剩余是正的。

Nonlinear aeroelastic analysis of the folding fin with freeplay under thermal environment

The nonlinear aeroelastic behavior of a folding fin in supersonic flow is investigated in this paper.The finite element model of the fin is established and the deployable hinges are represented by three torsion springs with the freeplay nonlinearity.The aerodynamic grid point is assumed to be at the center of each aerodynamic box for simplicity.The aerodynamic governing equation is given by using the infinite plate spline method and the modified linear piston theory.An improved fixed-interface modal synthesis method,which can reduce the rigid connections at the interface,is developed to save the problem size and computation time.The uniform temperature field is applied to create the thermal environment.For the linear flutter analyses,the flutter speed increases first and then decreases with the rise of the hinge stiffness due to the change of the flutter coupling mechanism.For the nonlinear analyses,a larger freeplay angle results in a higher vibration divergent speed.Two different types of limit cycle oscillations and a multiperiodic motion are observed in the wide range of airspeed under the linear flutter boundary.The linear flutter speed shows a slight descend in the thermal environment,but the effect of the temperature on the vibration divergent speed is different under different hinge stiffnesses when there exists freeplay.