Phase characterisation of metalenses

Metalenses have emerged as a new optical element or system in recent years, showing superior performance and abundant applications. However, the phase distribut...     

Nanocarrier-Loaded Imidaclothiz Promotes Plant Uptake and Decreases Pesticide Residue

There is a great demand for improving the effective utilization of pesticides and reducing their application for sustainable agriculture, and polymeric nanoparticles have provided strong technical support for the efficient delivery of pesticides. To this context, we tried to construct a relatively safe imidaclothiz nano-delivery system for enhanced plant uptake, reduced pesticide residue and improved bioactivity toward green peach aphids. The imidaclothiz could be assembled with the hydrophobic core of SPc through hydrophobic association, which led to the self-assembly of nanoscale imidaclothiz/SPc complex consisting of nearly spherical particles. The SPc decreased the contact angle of imidaclothiz drops and remarkably increased the plant uptake. Furthermore, the bioactivity and control efficacy of imidaclothiz were significantly improved with the help of SPc in both laboratory and field. Excitingly, the residue of imidaclothiz decreased with the help of SPc 7 d after the treatment due to the faster degradation of nanoscale imidaclothiz/SPc complex, which exhibited no negative effects on agronomic traits of tobacco plants. The current study successfully constructed a nano-delivery system for imidaclothiz, which can not only increase the effective utilization of pesticides, but also decrease the pesticide residue.     

几种纳米加工技术的原理、特点及其应用

从整体上介绍了基于传统半导体加工的纳米加工技术、探针直接书写式纳米加工技术、纳米复制加工技术,以及这几种纳米加工技术的原理、特点及其应用。     

基于矩阵束方法的传输线系统瞬态响应分析

带有频变负载的传输线系统的瞬态响应分析是电磁兼容领域的一个重要内容,特别是对于频变负载网络较为复杂或内部结构不清晰的情况,其瞬态响应的分析较为困难。本文首先在采样频率点处对频变负载端口导纳进行测量或计算得到相应的采样导纳,并采用有理函数逼近的方式对端口导纳进行等效;之后采用矩阵束(MPM)方法求解出有理逼近函数所需的极点和留数,并将其代入到分段线性递归卷积(PLRC)技术中,实现传输线和频变负载连接点处电压的分段线性递归卷积表达;最后,结合传输线方程实现带有频变负载的传输线系统的瞬态响应分析,并通过2个算例对所提方法的性能进行验证。结果表明,所提方法在计算精确度上具有明显的优势。     

窨制方式对玫瑰红茶品质的影响

传统花茶的窨制主要是以鲜花与茶叶结合,为探究不同的窨制方法对玫瑰红茶的滋味和品质的影响,通过4种窨制方法（鲜花赋香、玫瑰细胞液喷洒赋香、玫瑰细胞液蒸气赋香、花瓣与细胞液蒸气结合赋香）对红茶进行赋香,完成玫瑰红茶的窨制。以色差、茶多酚总量、游离氨基酸含量、儿茶素等指标为依据,结合HS-SPME-GC-MS对不同窨制工艺制得的玫瑰红茶香气成分进行分析。结果表明,4种赋香方式所得玫瑰红茶的理化成分具有显著性差异（P<0.05）。用鲜花赋香和细胞液喷洒赋香的两种红茶茶汤偏红、偏黄,明亮度不及其它2种赋香方式。以喷洒玫瑰细胞液的窨制方式得到的玫瑰红茶氨基酸含量较高（112.66 mg/L）;以玫瑰鲜花窨制得到的玫瑰红茶茶多酚含量较低（680.38 mg/L）。玫瑰红茶的主要呈香化合物为苯乙醛、芳樟醇、（E,E）-2,4-庚二烯醛、水杨酸甲酯、乙酸苯乙酯、β-紫罗酮、香叶醇、2-正戊基呋喃和正己醛这9种,玫瑰鲜花细胞液窨制的玫瑰红茶中含有的9种主要呈香化合物显著高于其它3种。本研究有助于创新玫瑰红茶的窨制方式,为高品质玫瑰红茶的窨制提供参考。     

MicroRNAs as Potential Biomarkers in the Differential Diagnosis of Lipomatous Tumors and Their Mimics

Adipocytic tumors are the most common subtype of soft tissue tumors. In current clinical practice, distinguishing benign lipomas from well-differentiated liposarcomas (WDLPS), as well as dedifferentiated liposarcomas (DDLPS) from their morphologic mimics, remains a significant diagnostic challenge. This is especially so when examining small biopsy samples and without the aid of additional ancillary tests. Recognizing the important role that microRNAs (miRNAs) play in tumorigenesis and their potential utility in tumor classification, we analyzed routine clinical tissue samples of benign and malignant lipomatous tumors, as well as other sarcoma mimics, to identify distinguishing miRNA-based signatures that can aid in the differential diagnosis of these entities. We discovered a 6-miRNA signature that separated lipomas from WDLPS with high confidence (AUC of 0.963), as well as a separate 6-miRNA signature that distinguished DDLPS from their more aggressive histologic mimics (AUC of 0.740). Functional enrichment analysis unveiled possible mechanistic involvement of these predictive miRNAs in adipocytic cancer-related biological processes and pathways such as PI3K/AKT/mTOR and MAPK signaling, further supporting the relevance of these miRNAs as biomarkers for adipocytic tumors. Our results demonstrate that miRNA expression profiling may potentially be used as an adjunctive tool for the diagnosis of benign and malignant adipocytic tumors. Further validation studies are warranted.     

测井技术的发展给仪修工程师带来的挑战

随着测井技术及仪器的发展,仪器的设计与制造越来越集成化,常规的维修方法逐渐落后。文章介绍了测井技术的发展趋势及测井仪器维修现状,阐述了只具备传统维修技术的仪修工程师对此面临的挑战,并分析了应对措施。     

混凝沉淀工艺对不同优势藻类的去除特性研究

为了考察混凝沉淀工艺的除藻性能在不同藻类优势期内的变化,将试验过程分为绿藻优势期和蓝藻优势期两个阶段,进行进水藻类群落结构特征及其变化对混凝沉淀除藻效能的影响研究.结果表明,混凝沉淀在绿藻优势期和蓝藻优势期的除藻效率分别为68.3%和40.4%,且各种藻类的去除效能并无明显的相互影响.蓝藻优势期的藻类去除率大大低于绿藻优势期,其根本原因在于占优势地位的微囊藻的生理生态特征.因此,把水中的所有藻类笼统地作为一个去除对象是不适宜的,应分析水中藻类群落结构特征,并根据特定原水中的优势藻种类进行针对性的除藻方案研究.     

石墨烯基导热薄膜的研究进展

随着现代技术的发展,散热和导热已成为制约芯片器件小型化和大功率制造业发展的关键问题之一。由于传统的金属导热材料存在密度大和易氧化等问题,近年来以石墨烯基材料为代表的非金属碳基材料逐渐成为国内外的研究热点。本文综述了近年国内外石墨烯导热薄膜的制备方法及最新研究成果,分析讨论了热处理工艺、晶粒尺寸、薄膜密度及杂质原子和缺陷等对石墨烯导热薄膜性能的影响和物理机理,并对该领域的发展趋势进行了展望。