摘要：Mandibular defect occurs more frequently in recent years,and clinical repair operations via bone transplantation are difficult to be further improved due to some intrinsic *** engineering,which is a hot research field of biomedical engineering,provides a new direction for mandibular defect *** the basis and key part of tissue engineering,scaffolds have been widely and deeply studied in regards to the basic theory,as well as the principle of biomaterial,structure,design,and fabrication ***,little research is targeted at tissue regeneration for clinic repair *** mandibular bone has a special structure,rather than uniform and regular structure in existing studies,a methodology based on tissue engineering is proposed for mandibular defect repair in this *** steps regarding scaffold digital design,such as external shape design and internal microstructure design directly based on triangular meshes are discussed in *** analyzing the theoretical model and the measured data from the test parts fabricated by rapid prototyping,the feasibility and effectiveness of the proposed methodology are properly *** works about mechanical and biological improvements need to be done to promote its clinical application in future.

摘要：In maxillofacial surgery, there is a significant need for the design and fabrication of porous scaffolds with customizable bionic structures and mechanical properties suitable for bone tissue engineering. In this paper, we characterize the porous Ti6Al4V implant, which is one of the most promising and attractive biomedical applications due to the similarity of its modulus to human bones. We describe the mechanical properties of this implant, which we suggest is capable of providing important biological functions for bone tissue regeneration. We characterize a novel bionic design and fabrication process for porous implants. A design concept of “reducing dimensions and designing layer by layer” was used to construct layered slice and rod-connected mesh structure (LSRCMS) implants. Porous LSRCMS implants with different parameters and porosities were fabricated by selective laser melting (SLM). Printed samples were evaluated by microstructure characterization, specific mechanical properties were analyzed by mechanical tests, and finite element analysis was used to digitally calculate the stress characteristics of the LSRCMS under loading forces. Our results show that the samples fabricated by SLM had good structure printing quality with reasonable pore sizes. The porosity, pore size, and strut thickness of manufactured samples ranged from (60.95± 0.27)% to (81.23±0.32)%,(480±28) to (685±31)μm, and (263±28) to (265±28)μm, respectively. The compression results show that the Young’s modulus and the yield strength ranged from (2.23±0.03) to (6.36±0.06) GPa and (21.36±0.42) to (122.85±3.85) MPa, respectively. We also show that the Young’s modulus and yield strength of the LSRCMS samples can be predicted by the Gibson-Ashby model. Further, we prove the structural stability of our novel design by finite element analysis. Our results illustrate that our novel SLM-fabricated porous Ti6Al4V scaffolds based on an LSRCMS are a promising material for bone implants, and are potential

摘要：Mandibular defect occurs more frequently in recent years,and clinical repair operations via bone transplantation are difficult to be further improved due to some intrinsic *** engineering,which is a hot research field of biomedical engineering,provides a new direction for mandibular defect *** the basis and key part of tissue engineering,scaffolds have been widely and deeply studied in regards to the basic theory,as well as the principle of biomaterial,structure,design,and fabrication ***,little research is targeted at tissue regeneration for clinic repair *** mandibular bone has a special structure,rather than uniform and regular structure in existing studies,a methodology based on tissue engineering is proposed for mandibular defect repair in this *** steps regarding scaffold digital design,such as external shape design and internal microstructure design directly based on triangular meshes are discussed in *** analyzing the theoretical model and the measured data from the test parts fabricated by rapid prototyping,the feasibility and effectiveness of the proposed methodology are properly *** works about mechanical and biological improvements need to be done to promote its clinical application in future.

摘要：荧光各向异性方法又称荧光偏振法,基于相互作用的分子结合前后发射光退偏振的不同而实现对相互作用的研究或对目标物的检测。20世纪50年代Gregorio Weber用荧光各向异性法研究了氮磺酰氯与牛血清白蛋白和卵清白蛋白的作用,开启了该方法在生物化学研究中应用的先河。而20世纪90年代开始的功能性核酸(FNAs,包括核酸适配体和核酸酶等)的发现与合成,使基于功能性核酸的传感得到了广泛的应用。核酸适配体能够特异性识别目标分子,基于核酸识别的荧光各向异性分析方法具有高选择性、高灵敏度、高通量等优势,在研究蛋白质、核酸和小分子的相互作用中起到重要作用,然而如何提高结合前后的荧光各向异性信号变化,尤其是小分子识别前后,在基于功能性核酸识别的分析方法发展中是一个挑战。介绍了基于功能性核酸识别的荧光各向异性的方法应用于检测蛋白质、核酸及其他在生命活动中起重要作用的小分子的基本原理及设计理念。

摘要：一体化闭式循环快堆核能系统,简称一体化快堆,是核裂变能发展的高级阶段。为确保其满足先进核能系统的定位,应基于一体化快堆的特点及用户需求,开展顶层设计要求研究,为后续设计和技术研发指明方向。国际上对第四代核能系统的评价建立了相关方法学,本文结合第四代核能系统评价方法学关注的经济性、安全性、可持续性及防核扩散等方面,特别是与设计相关的用户要求条款,研究提出一体化快堆的顶层设计要求,为开展一体化快堆设计工作设定设计目标或指标要求。

摘要：毕业设计是培养学生工程实际应用能力和创新意识的重要实践性教学环节,在本科教育中占有非常大的比例。同时,校企联合指导毕业设计的教学模式是本科生教学的发展趋势。本文针对建筑环境与能源应用工程专业的应用特点,提出了校企联合指导建环专业毕业设计的教学模式。

摘要：结构的抗爆性是悬浮隧道设计中不可回避的问题,为了提高悬浮隧道结构的抗爆能力并对其结构形式进行优化,运用LS-DYNA有限元软件建立水下爆炸作用下悬浮隧道流固耦合模型,通过将二维水下爆炸冲击波映射到三维结构体上的方法,选取了具有代表性的3种结构形式(混凝土结构、钢板+混凝土组合结构和泡沫铝+混凝土组合结构)进行悬浮隧道管体水下爆炸动力响应计算,以结构位移、压力、有效应力以及应变作为评价结构抗爆性能的指标,分析了不同结构形式和防护方式对结构抗爆性能的影响。结果表明:①在混凝土厚度对结构抗爆性计算分析中,当混凝土管体厚度在1.1~1.43 m范围时,悬浮隧道抗爆性能随着厚度的增加显著提高,但超过此区间,抗爆性能表现出饱和趋势,厚度对管体的抗爆性影响有限;②在钢板防护对结构抗爆性计算分析中,钢管混凝土结构整体防护性能要优于外侧钢板,能够有效减小高应力范围,但对位移变形范围影响不显著,内侧钢板防护并不适用于外部水下爆炸的情况,钢管混凝土应力峰值与位移峰值相比混凝土结构减小了16.10%和17.63%;③在外侧泡沫铝防护的抗爆性计算分析中,由于泡沫铝材料多孔隙性的特点,能够有效吸收和分散作用在管体上的爆炸能量,因此其位移峰值和应力相比混凝土结构分别减小了23.11%和25.40%,整体抗爆性能要优于其他2种防护形式。

摘要：采用压裂技术提升煤层气储层渗透性是强化煤层气开发的重要途径。对于深部高温煤层气储层,液氮压裂技术通过在煤层中注入低温液氮形成显著热应力,基于冷冲击作用可实现对煤层气储层的致裂增渗。为研究液氮作用对高温煤岩的力学特性及损伤破裂特征的影响机制,对加热至不同温度条件下的煤样进行液氮冷却处理,通过波速测试和巴西劈裂测试,研究液氮对高温煤样波速、强度、声发射和裂纹演化等特征及破裂模式的影响机制。结果表明:高温煤样在液氮冷却作用后,力学性能出现了显著劣化,P波波速降低,超声频率分化严重,主频由51.10 kHz降至40.88 kHz。煤样逐渐由脆性破坏向延性破坏转变,巴西劈裂模量和脆性指数降幅最高分别为67%和75%。在巴西劈裂荷载下,煤样内部声发射信号均表现为低RA值、高AF值;煤样内部破坏形式主要为拉伸破坏,其次为剪切破坏。随着煤样初始温度的增加,煤样断裂面上形成多个起伏区域,3维形貌扫描的最大波峰与最大波谷高度差最高可达37.60 mm。液氮冷却诱导的微裂隙交叉扩展形成复杂的裂纹网络,进而导致局部失效区域的形成和煤样断裂面复杂化。表观裂纹分形维数在初始加热温度为100℃时达到最大值,由初始20℃时的0.50增加到1.83。研究结果可为深部高温煤层液氮压裂设计提供理论参考。

摘要：为探究紊动对水体中溶氧释放的促进效果,设计以潜水泵排水的方式,开展了不同水泵数量、功率、摆放方式、排水方向等工况下过饱和溶氧释放过程研究试验。结果表明,紊动对水体中溶氧释放有较好的促进效果。放入5个泵(功率20 W、纵向排水)时,水体溶氧释放系数为0.514 h^(-1),是未放入水泵时溶氧释放系数0.026 h^(-1)的19.77倍。当水泵垂直于水面排水时,溶氧释放效果较好。水泵个数越多、功率越大,溶氧释放系数越大,溶氧释放效果越好。

摘要：A conventional Fowler flap is designed to improve the take-off and landing performances of an aircraft. Because the flight states of general aviation aircraft vary significantly. A Fowler flap with a double-sliding track has been designed, which is ca- pable of changing airfoil camber while cruising and climbing as well as meeting low-speed performance requirements. The aerodynamic characteristics of the variable camber Fowler flap were studied by computational simulation, and cambering was found to be beneficial for improving the lift-to-drag ratio when the lift coefficient was larger than the critical value, below which decambering was more effective; this critical value differed somewhat under different conditions. Taking the mecha- nism into account, the take-off and landing configurations were optimized on the basis of the GA （W）-1 airfoil with a 30% chord Fowler flap. Compared with reference configuration, the maximum lift coefficient of optimized take-off configuration was increased by 6.6% as well as the stalling angle and the lift-to-drag ratio were increased by 1.3° and 7.58%, respectively. Moreover, the maximum lift coefficient of the optimized landing configuration was increased by 6.3%, and the stalling angle was increased by 1.1°; however, the nose-down pitching moment of both configurations increased. Similar results were at- rained on a general aviation aircraft wing/body combination nism was established in a computer-aided design system, achieved by the double-sliding track. A 3D model of the variable-camber Fowler flap driving mecha- and the results showed that all design configurations could be