对称消声器传递损失测量及误差修正

为了提高对称消声器传递损失的测量效率，基于声学理论分析，提出了一种单负载法传递损失计算模型。针对反射系数较大的吸声末端，导致该方法在实际测量中存在较大误差的问题，推导出了一种能够消除测试管道末端反射声波在上、下游形成多次反射的修正公式。通过自制阻抗管进行试验测试，结果表明：在末端声学负载吸声性能良好的情况下，单负载法传递损失计算模型能够精确计算出对称消声器的传递损失；修正公式能够有效地消除末端负载所引起的反射波对传递损失计算的影响，降低对末端声学负载吸声性能的要求，保证单负载传递损失计算模型的适用性。     

磁絮凝强化技术处理厌氧消化污泥脱水液

为满足后续生物处理单元对固体悬浮物（SS）和铁浓度的进水要求，采用磁絮凝强化技术对厌氧消化污泥脱水液进行预处理。通过正交试验和单因素试验，本文考察了混凝水力条件、聚合氯化铝（PAC）投加量、聚丙烯酰胺（PAM）投加量、磁粉投加量及药剂投加顺序对磁絮凝效果的影响。试验结果表明：磁絮凝强化技术在快搅300r/min（2min）、慢搅100r/min（15min）、静置10min时，依次投加磁粉（40mg/L）、PAC（30mg/L）、PAM（4mg/L）时处理效果最好。在此运行条件下，SS和Fe³⁺去除率分别为97.61%、98.24%、絮凝指数（FI值）取得最大值、zeta电位绝对值最小，絮凝效果最佳。与对照相比，磁絮凝强化技术对SS和Fe³⁺去除率分别可提高3.70%和10.82%，同时絮体最大沉降速度可提高33%。磁絮凝技术处理后的出水不仅可以满足后续生物处理单元对SS和铁浓度的要求，还可以有效提高磁絮凝体的沉降速度，减小沉淀时间，具有较好的实用价值。     

基于ANSYS及加速寿命试验台对油缸单耳环活塞杆杆头断裂进行设计改进

该文对某工程机械油缸单耳环活塞杆杆头断裂进行失效分析,提出了在毛坯锻造工艺满足设计要求的条件下,单耳环活塞杆杆头变截面处应力集中导致残余应力过大,是单耳环活塞杆杆头断裂的主要原因。从这方面出发,优化了单耳环活塞杆杆头变截面处的残余应力,通过ANSYS软件对优化后的结构进行应力分析,并用油缸加速寿命可靠性试验台做2F台架实验和整机多批次小批量试装来验证改进措施的有效性,最终提高了油缸单耳环活塞杆杆头在极限工况下抗疲劳的强度。     

基于环三磷腈磷氮阻燃剂的合成及其在聚氨酯泡沫的应用

以六氯环三磷腈、对羟基苯甲醛、苯胺及亚磷酸二乙酯等原料，成功合成阻燃剂六（4-苯胺基次甲基苯氧基-亚磷酸二乙酯基）环三磷腈（HADPPCP），用于阻燃基于苹果酸多元醇的聚氨酯硬泡。HADPPCP具有良好的热稳定性和成炭性，氮气气氛下的初始分解温度为191.9℃，700℃时的残炭量高到46.8%（质量）。HADPPCP的加入可以改善聚氨酯硬泡的热稳定性、阻燃性能和燃烧行为。添加25%(质量)的HADPPCP可以将聚氨酯泡沫的氧指数从18%提高到25%，最大热释放速率和总热释放量分别从230 kW/m²和20.1 MJ/m²降低至213 kW/m²和16.6 MJ/m²，总产烟量从10.5 m²下降到5.3 m²。     

锂电池回收再生石墨增强水泥性能研究

废弃锂离子电池的负极活性材料主要为石墨,现阶段对于废弃锂离子电池中的石墨主要采用填埋等方法进行处理,造成了资源的浪费和环境的污染。现有的研究表明,废弃锂离子电池中的石墨经高温热解及酸浸处理后可以得到纯净的再生石墨,采用再生石墨增强水泥基复合材料的力学性能和电学性能。结果表明：再生石墨的引入可以增强材料的抗压性能和抗折性能,最大增幅分别达到了57.3%和84.4%。此外,再生石墨的加入有效降低了材料的电阻率,减少了极化时间,当再生石墨的掺加量为3%时,养护28 d后材料的电阻率仅为249 Ω·cm。该复合材料还具有典型的压敏特性。所制备的复合材料有望用于混凝土材料结构的实时动态监测。此外,对于废弃锂离子电池的全组分回收利用及功能水泥材料的研发具有重要意义。     

线性富磷化阻燃剂在聚氨酯泡沫中的应用研究

通过界面聚合法合成了一种线性富磷化阻燃剂（LPRFR），将LPRFR与可膨胀石墨（EG）复配制备了阻燃聚氨酯泡沫（RPUF），使用红外光谱分析仪、核磁共振分析仪对阻燃剂LPRFR的化学结构进行了表征，并通过极限氧指数仪、锥形量热仪、扫描电子显微镜和红外光谱分析仪对RPUF的燃烧性能、微观形貌和化学结构进行了分析。结果表明，仅10 %（质量分数，下同）的LPRFR 与8 %EG复配后，RPUF的极限氧指数（LOI）便达到26.1 %；LPRFR和EG能大幅降低RPUF的热释放速率，并提高基体的成炭能力； LPRFR参与了燃烧过程中的成炭反应，形成了含P—O—C及P=O结构的高质量炭层，有效隔绝了氧气和热量；LPRFR是一种对于聚氨酯泡沫阻燃性能优异的新型阻燃剂。     

Development of fan‐shaped tracker for single particle tracking

With the development of super‐resolution fluorescence microscopy, complex dynamic processes in living cells can be observed and recorded with unprecedented temporal and spatial resolution. Single particle tracking (SPT) is the most important step to explore the relationship between the spatio‐temporal dynamics of subcellular molecules and their functions. Although previous studies have developed SPT algorithms to quantitatively analyze particle dynamics in cell, traditional tracking methods have poor performance when dealing with intersecting trajectories. This can be attributed to two main reasons: (a) they do not have point compensation process for overlapping objects; (b) they use inefficient motion prediction models. In this paper, we present a novel fan‐shaped tracker (FsT) algorithm to reconstruct the trajectories of subcellular vesicles in living cells. We proposed a customized point compensation method for overlapping objects based on the fan‐shaped motion trend of the particles. Furthermore, we validated the performance of the FsT in both simulated time‐lapse movies with variable imaging quality and in real vesicle moving images. Meanwhile, we compared the performance of FsT with other five state‐of‐the‐art tracking algorithms by using commonly defined measures. The results showed that our FsT achieves better performance in high signal‐to‐noise ratio conditions and in tracking of overlapping objects. We anticipate that our FsT method will have vast applications in tracking of moving objects in cell.     

Analysis of optoelectronic and trasnport properties of magnesium based MgSc2X4 (X=S,Se) spinels for solar cell and energy storage device applications

Intense research work is underway for identifying materials with potential applications in energy storage and energy harvesting systems. The magnesium based scandium chalcogenides have recently emerged as potential candidates for Mg batteries owing to their high Mg ionic conductivity and low electron conduction. At the same time, their band gaps are capable of absorbing electromagnetic radiations in visible to UV range; making them suitable for solar cell applications. In order to analyze the application of MgSc₂X₄(X = S, Se) compounds in energy devices, in this work we employ density functional theory calculations using the full potential linear augmented plane-wave method for examining their optoelectronic and thermoelectric properties. For the structural properties, the generalized gradient approximation functional designed for solids (PBEsol-GGA) has been used, while modified Becke and Johnson (mBJ) potential functional is used for computing the optoelectronic and transport properties. Our calculated optical properties indicate that these materials can find applications in solar cells. Moreover, the electronic transport properties computed using Boltzmann transport equation suggest carrier concentrations in MgSc₂S₄ to MgSc₂Se₄ spinels can be tuned for making them suitable for metal ion batteries.