Addition of alkynes and osmium carbynes towards functionalized dπ-pπ conjugated systems

碳-碳三键和碳-金属三键是两类高度不饱和的化学键。该工作发现了这两类三键之间的全新反应模式。利用该反应能把金属和有机π共轭体系有效结合，得到一类金属d轨道参与π共轭的全新大π共轭体系。化学化工学院夏海平教授课题组碳龙化学研究取得新进展，利用金属卡拜与炔烃的新反应，成功地合成了一类金属d轨道参与π共轭的全新共轭体系并在有机太阳能电池领域得到应用。该工作是在夏海平教授和南方科技大学何凤副教授共同指导下完成的。化学化工学院2016级iChEM博士生陈仕焰和南科大博士生刘龙珠为论文的共同第一作者。该工作充分体现了多学科协同创新研究优势：相关化合物合成、表征由陈仕焰、高翔、彭丽霞、张颖等完成；光电测试由刘龙珠完成；理论计算由陈仕焰、华煜晖完成。化学化工学院杨柳林副教授、谭元植教授等对研究工作给予了大力支持。【Abstract】The metal-carbon triple bonds and carbon-carbon triple bonds are both highly unsaturated bonds. As a result, their reactions tend to afford cycloaddition intermediates or products. Herein, we report a reaction of M≡C and C≡C bonds that affords acyclic addition products. These newly discovered reactions are highly efficient, regio- and stereospecific, with good functional group tolerance, and are robust under air at room temperature. The isotope labeling NMR experiments and theoretical calculations reveal the reaction mechanism. Employing these reactions, functionalized dπ-pπ conjugated systems can be easily constructed and modified. The resulting dπ-pπ conjugated systems were found to be good electron transport layer materials in organic solar cells, with power conversion efficiency up to 16.28% based on the PM6: Y6 non-fullerene system. This work provides a facile, efficient methodology for the preparation of dπ-pπ conjugated systems for use in functional materials.This research was supported by the National Natural Science Foundation of China (Nos. U1705254, 21931002, and 21975115), Guangdong Provincial Key Laboratory of Catalysis (No. 2020B121201002), Shenzhen Nobel Prize Scientists Laboratory Project (no.C17783101), and the National Key R&D Program of China (2017YFA0204902). We thank the SUSTech Core Research Facilities for the Holiba-UVISEL measurements. 研究工作得到了国家自然科学基金(U1705254、21931002、21975115)，广东省催化化学重点实验室(No. 2020B121201002)，国家重点研发计划(2017YFA0204902)，及深圳诺贝尔奖科学家实验室(C17783101)等项目资助

Research Progress on Acoustic Model of Porous Sound Absorbing Materials and Measurement Method of Its Characteristic Parameters

噪声是载人航天器的重要环境因素之一,航天器环境噪声升高会直接影响航天员工作和休息,进而影响空间科学任务。然而,以往在轨运行的载人航天器存在较多噪声过大的问题,多孔吸声材料已经在国际空间站应用并取得良好的降噪效果,我国空间站预计2022年底建成,了解声学多孔材的声学模型以及吸声机理对我空间站运营阶段的降噪具有重要的意义。基于刚性框架假设,多孔吸声材料声学等效模型分为经验模型和唯像模型,Delany-Bazley是常用的经验模型,采用此模型不能对多孔材料吸声的性能提供精确的预测,唯象模型考虑了声波在材料孔隙和空腔中的传播,可以准确预测吸声性能,因此Johnson-Champoux-Allard唯象模型被众多学者应用。流阻、孔隙率、曲率、粘胶特征长度和热特性长度等多孔材料声学特性参数是准确建立多孔材料Johnson-Champoux-Allard模型的关键,流阻测试方法包括直接气流法、声学阻抗管法、交流法和比较法;孔隙率的测试方法分为直接测试方法和声学阻抗管测试方法;曲率、粘性特征长度和热特性长度可以通过超声波进行直接测试,直接测量通常比较复杂、不太可靠并且具有破坏性,反演优化方法是获得多孔材料曲率、粘性特征长度和热特性长度的常用方法。本文概述了多孔吸声材料在国际空间站的应用情况,综述了多孔吸声材料声学等效模型的研究进展,介绍了多孔吸声材料吸声原理、声学扰动基本方程以及声学属性参数的测试方法,重点介绍了多孔吸声材料声学等效模型中的经验模型和唯像模型,进而对多孔材料声学等效模型中的声学特征参数的测试方法进行详细论述。</p

基于主成分分析法与逼近理想解法的38MnVS6激光熔覆工艺研究

采用激光熔覆在燃烧室部件表面制备高性能涂层对延长柴油机寿命有重要意义,多工艺参数的优化是获得高性能熔覆层的关键。以激光功率、扫描速度和送粉速率为优化对象,以熔覆层宽度、稀释率和表面硬度为优化目标,对活塞用38MnVS6中碳钢基体表面激光熔覆镍基合金粉末进行了L_9(3~3)正交试验。基于主成分分析法计算各目标权重,并采用马氏距离的逼近理想解法对试验数据进行分析,获得了如下最佳工艺参数组合:激光功率850 W、扫描速度3 mm/s、送粉速率3. 13 g/min.经试验验证,与L_9(3~3)正交试验最佳方案相比,稀释率下降了1. 13%,平均硬度提高了4. 56%.通过极差分析,得到工艺参数对熔覆层综合质量和熔池尺寸的影响由大到小依次为激光功率、送粉速率、扫描速度

基于主成分分析法与逼近理想解法的38mnvs6激光熔覆工艺研究

采用激光熔覆在燃烧室部件表面制备高性能涂层对延长柴油机寿命有重要意义,多工艺参数的优化是获得高性能熔覆层的关键。以激光功率、扫描速度和送粉速率为优化对象,以熔覆层宽度、稀释率和表面硬度为优化目标,对活塞用38MnVS6中碳钢基体表面激光熔覆镍基合金粉末进行了L_9(3~3)正交试验。基于主成分分析法计算各目标权重,并采用马氏距离的逼近理想解法对试验数据进行分析,获得了如下最佳工艺参数组合:激光功率850 W、扫描速度3 mm/s、送粉速率3.13 g/min.经试验验证,与L_9(3~3)正交试验最佳方案相比,稀释率下降了1.13%,平均硬度提高了4.56%.通过极差分析,得到工艺参数对熔覆层综合质量和熔池尺寸的影响由大到小依次为激光功率、送粉速率、扫描速度

Effect of droplet impact on molten pool dynamics in hybrid laser-MIG welding of aluminum alloy

In order to investigate the effect of droplet impact on molten pool dynamics in hybrid laser-MIG (metal inert gas) welding, a three-dimensional mathematical model was developed, and a new approach to simulate the droplet impact was proposed. In the model, the droplet heat and impact under the influence of laser was considered, and the deformation of molten pool was calculated with considering droplet impact and arc pressure. To simplify the model, a modified body heat source model was presented for laser source to take into account multiple reflections and Fresnel absorption. Surface tension, electromagnetic force, and buoyancy were considered to calculate the fluid flow pattern. Furthermore, several dimensionless numbers were used to recognize the importance of the driving forces in molten pool. It was found that molten pool dynamics and final weld bead geometry were strongly affected by the droplet impact. To demonstrate the importance of droplet impact, the temperature, velocity distribution, and the deformation of molten pool were analyzed and compared under different conditions. With considering droplet impact, the penetration was bigger, and the width was smaller. Furthermore, the simulated weld bead geometry was in good agreement with experimental measurement

Surface hardening of steel by pulse laser with proportional intensity distribution spots

激光硬化层均匀性受光束空间强度分布和作用时间的影响.采用二元光学变换技术得到光束中心线强度比值为1:2:3,3:2:1和1:1:1的5×5点阵光斑,研究这三种强度分布光斑对Q235钢脉冲激光硬化后表面形貌,硬化层形状,硬度及耐磨性的影响.结果表明,激光光斑的空间强度分布对Q235钢硬化层均匀性影响很大,1:2:3强度分布光斑作用下的材料表面形貌,硬化层均匀性,硬度均匀度均优于1:1:1强度分布光

铝合金激光-MIG复合焊焊缝力学性能研究

对高铁车身用6N01铝合金进行激光-MIG复合焊接实验,并对焊缝力学性能进行了研究.测定了从焊缝区至热影响区及母材的硬度变化,得到了焊缝的抗拉强度及拉伸曲线,拟合出了疲劳寿命趋势线,而且观测了断口形貌并测定了断口成分

纯镍与304不锈钢激光异种焊接的工艺及其接头的组织性能

采用高密度Nd：YAG固态连续激光器对N6纯镍和304奥氏体不锈钢进行了焊接工艺实验,探究了激光功率和离焦量对焊缝成形的影响。对接头进行了拉伸强度和硬度的测试,并结合光学显微镜（OM）、扫描电镜（SEM）、能谱分析仪（EDS）等手段分析了接头的微观组织。结果表明：N6纯镍一侧热影响区晶粒长大明显,焊缝区靠近两侧熔合线附近为向焊缝中心区域生长的柱状晶,焊缝中心区域存在细小的胞晶区域;N6热影响区的显微硬度最低,焊缝的显微硬度介于N6镍母材和304不锈钢母材之间;接头拉伸断裂位置在焊缝区,抗拉强度达到N6纯镍母材的90%以上,可以满足实际情况下的使用要求。拉伸断口表现为准解理断裂

DPSIR Model-based Assessment of ecologically sustainable development in Shandong Peninsula Blue Economic Zone

山东半岛作为我国最大的半岛,其地理位置决定了海洋生态可持续发展对其的重要性。本文使用DPSIR(驱动力-压力-状态-影响-响应)模型,结合社会经; 济和自然生态两个方面搭建指标体系评估其蓝色经济区生态可持续发展能力。结果表明:山东半岛承受的社会经济压力正不断增大。海洋生态系统综合状态评价值为; 0.53,其中海水、沉积物质量及生物综合评价值分别为0.22、0.19及0.123,生态环境现状不容乐观。影响和响应评价值分别为2.5和4.3,; 海洋灾害的影响范围较大,危害程度较深,但海洋管理部门在面对生态环境变化时的反应较为迅速、有效。Shandong Peninsula is the largest peninsulas in China and its; geographical position plays a vital role in its ecological health. In; this paper, we used the Driving-Pressure-State-Impact-Response (DPSIR); model, combined with social economic and natural ecological parameters,; to establish an ecologically sustainable development evaluation index; system. The results show there to be increasing social and economic; pressures on the Shandong Peninsula, and the comprehensive state; evaluation value for its ecological system is 0.5313. The water,; sediment and biological quality values are 0.22, 0.19, and 0.123,; respectively. Current conditions are not encouraging. The impact; indicator and response indicator values are 2.5 and 4.7, respectively,; which indicates that marine disasters have great influence on the; Peninsula and can cause serious damage, although the government's; response to changes in the ecological environment is typically quick and; efficient.山东省优秀中青年科学家科研奖励基金计划项