薄膜基荧光气体传感器中的涂层化学

近年来,高性能薄膜基气体传感器的研制备受关注,所涉及的涂层化学已经成为物理化学学科发展的一个热点。传感因分析物与敏感层(涂层)物质相互作用引起薄膜特定静态及动态物理量变化而实现,因此,薄膜传感性能势必受到敏感层物质种类和敏感层微纳结构等因素影响。就薄膜基荧光传感而言,荧光敏感物质的结构和性质对薄膜传感性能起着至关重要的作用。同时,因毛细凝结、色谱效应、尺寸效应、分子间相互作用等因素的存在,敏感层微观结构也极大地影响着薄膜的传感性能。本文结合课题组近期研究工作,简要讨论薄膜基荧光气体传感器研究中的涂层化学基本问题,以及相关薄膜基荧光传感器在隐藏爆炸物、毒品、挥发性有机污染物检测/监测等方面的应用探索。最后,文章展望了薄膜基荧光气体传感器的发展前景和所面临的主要挑战。

谁影响我们?我们又影响谁?——我国新闻传播学学科内与学科间互引的网络分析

本研究运用社会网络分析法,先对我国新闻传播学15本核心期刊学科内互引网络进行分析,探究新闻传播学科内部的知识交流结构与动向,分析发现新闻传播学科内部期刊之间互引较为普遍,但每本期刊的自我引用率与国际期刊相比偏低,这可能与我国期刊在研究主题上偏综合化而非特色化有关;此后,本文根据这15本核心期刊与其他学科核心期刊的互引网络,探寻新闻传播学科与其他学科知识产出的相互影响。结果表明,出版、教育综合、戏剧电影与电视艺术是与新闻传播学期刊互动最为频繁的几个学科,它们共同形成了一个双向高频互引群体,其他学科在与新闻传播学科互动的过程中则形成了主题单一的聚类。

糖葫芦的发光之旅——从中华美食到碳量子点材料

糖葫芦是中华传统美食之一,作为美食,它家喻户晓、人见人爱。众所周知,精心熬制的糖浆是制作出美味糖葫芦的关键原料。有意思的是,当我们将糖葫芦放在紫外灯下观察的时候,可以看到糖浆还能发出漂亮的绿色荧光,这是为什么呢?这是因为,糖浆中含有一种荧光材料——碳量子点。本文从糖葫芦外层糖浆在紫外灯下会发出荧光的现象入手,详细研究糖葫芦糖浆和实验室制备糖浆的荧光性能和微观结构,并简单介绍碳量子点在生活和科研中的应用。

Research on the application of computer network remote control system

In this era of accelerated pace of life, high efficiency and superior quality has undoubtedly become the focus of attention. In this context, the computer has been the core component of our daily production, life and entertainment. In fact, the vast majority of modem areas cannot be separated from the computer, if separated from the computer, these areas are likely to be subject to enormous challenges and threats, so people and computer dependence are increasing. With the advent of the Internet era, the network and the economic, trade, cultural exchanges and other activities related to the increasingly problematic. The computer network remote control system is a new kind of multimedia network control system Network platform to carry out related construction. In this paper, the application of computer network remote control system as the core of the study, hoping to provide help for the majority of technical staff.

OsPRMT6a-mediated arginine methylation of OsJAZ1 regulates jasmonate signaling and spikelet development in rice

Although both protein arginine methylation(PRMT)and jasmonate(JA)signaling are crucial for regulating plant development,the relationship between these processes in the control of spikelet development remains unclear.In this study,we used the CRISPR/Cas9 technology to generate two OsPRMT6a loss-of-function mutants that exhibit various abnormal spikelet structures.Interestingly,we found that OsPRMT6a can methylate arginine residues in JA signal repressors OsJAZ1 and OsJAZ7.We showed that arginine methylation of OsJAZ1 enhances the binding affinity of OsJAZ1 with the JA receptors OsCOI1a and OsCOI1b in the presence of JAs,thereby promoting the ubiquitination of OsJAZ1 by the SCF^(OsCOI1a/OsCOI1b) complex and degradation via the 26S proteasome.This process ultimately releases OsMYC2,a core transcriptional regulator in the JA signaling pathway,to activate or repress JA-responsive genes,thereby maintaining normal plant(spikelet)development.However,in the osprmt6a-1 mutant,reduced arginine methylation of OsJAZ1 impaires the interaction between OsJAZ1 and OsCOI1a/OsCOI1b in the presence of JAs.As a result,OsJAZ1 proteins become more stable,repressing JA responses,thus causing the formation of abnormal spikelet structures.Moreover,we discovered that JA signaling reduces the OsPRMT6a mRNA level in an OsMYC2-dependent manner,thereby establishing a negative feedback loop to balance JA signaling.We further found that OsPRMT6a-mediated arginine methylation of OsJAZ1 likely serves as a switch to tune JA signaling to maintain normal spikelet development under harsh environmental conditions such as high temperatures.Collectively,our study establishes a direct molecular link between arginine methylation and JA signaling in rice.

基于双重距离的多目标粒子群优化算法

多目标粒子群优化(multi-objective particle swarm optimization,MOPSO)算法在维护收敛性的同时搜索分布良好的最优解集较为费力.为此,提出一种基于双重距离的MOPSO,由种群的平均距离定义粒子的邻域空间,邻域粒子数为粒子的等级,数量越多,粒子的等级越大.当等级相同时,算法结合粒子的拥挤距离选择最优粒子,并更新外部归档集.此外,算法结合粒子的变异行为避免陷入局部最优.在对比实验中,该算法在收敛性和多样性上可取得较优结果.最后,将该算法应用到电力系统的环境/经济调度模型(environmental/economic dispatch,EED),也可获得性能较好的解集.

Young Leaf White Stripe encodes a P-type PPR protein required for chloroplast development

Pentatricopeptide repeat(PPR) proteins function in post-transcriptional regulation of organellar gene expression. Although several PPR proteins are known to function in chloroplast development in rice(Oryza sativa), the detailed molecular functions of many PPR proteins remain unclear.Here, we characterized a rice young leaf white stripe(ylws) mutant, which has defective chloroplast development during early seedling growth.Map-based cloning revealed that YLWS encodes a novel P-type chloroplast-targeted PPR protein with 11 PPR motifs. Further expression analyses showed that many nuclear-and plastid-encoded genes in the ylws mutant were significantly changed at the RNA and protein levels. The ylws mutant was impaired in chloroplast ribosome biogenesis and chloroplast development under low-temperature conditions. The ylws mutation causes defects in the splicing of atpF, ndhA, rpl2,and rps12, and editing of ndhA, ndhB, and rps14transcripts. YLWS directly binds to specific sites in the atpF, ndhA, and rpl2 pre-mRNAs. Our results suggest that YLWS participates in chloroplast RNA group II intron splicing and plays an important role in chloroplast development during early leaf development.

A fluorescent film sensor for high-performance detection of Listeria monocytogenes via vapor sampling

Foodborne Listeria monocytogenes poses serious threats to public health.Fast and sensitive detection of the pathogen at the point of contamination is thus crucial to halt the spread of bacteria-related diseases.Herein,we report for the first time a fluorescent film sensor to detect the biomarker of L.monocytogenes,3-hydroxy-2-butanone.The sensor demonstrated unprecedented sensing performance for the analyte with a detection limit lower than 0.05 mg/m^(3),response time less than 1 s,full reversibility,and excellent selectivity.Further study showed that the sensor can be used to monitor the growth of L.monocytogenes with much-improved sensitivity.The superior performance of the sensor is ascribed to the specific binding,efficient charge transfer emission,and porous adlayer structure of the specially designed sensing fluorophore-based film.Our work paves the way to develop a portable detector to meet the needs for on-site and real-time detection of foodborne pathogens.

Ribonuclease H-like gene SMALL GRAIN2 regulates grain size in rice through brassinosteroid signaling pathway

Grain size is a key agronomic trait that determines the yield in plants.Regulation of grain size by brassinosteroids(BRs)in rice has been widely reported.However,the relationship between the BR signaling pathway and grain size still requires further study.Here,we isolated a rice mutant,named small grain2(sg2),which displayed smaller grain and a semi-dwarf phenotype.The decreased grain size was caused by repressed cell expansion in spikelet hulls of the sg2 mutant.Using map-based cloning combined with a Mut Map approach,we cloned SG2,which encodes a plant-specific protein with a ribonuclease H-like domain.SG2 is a positive regulator downstream of GLYCOGEN SYNTHASE KINASE2(GSK2)in response to BR signaling,and its mutation causes insensitivity to exogenous BR treatment.Genetical and biochemical analysis showed that GSK2 interacts with and phosphorylates SG2.We further found that BRs enhance the accumulation of SG2 in the nucleus,and subcellular distribution of SG2 is regulated by GSK2 kinase activity.In addition,Oryza sativa OVATE family protein 19(OsOFP19),a negative regulator of grain shape,interacts with SG2 and plays an antagonistic role with SG2 in controlling gene expression and grain size.Our results indicated that SG2 is a new component of GSK2-related BR signaling response and regulates grain size by interacting with Os OFP19.

Nonplanar Perylene Monoimide-Based Fluorescent Film for Enhanced BTX Sensing

Film-based fluoresce nt sen sors have been adapted into portable devices for the vapor phase detecti on.The satisfactory sensing performs nee(e.g.,sen sitivity,selectivity,reusability)largely bene fits from fluorophores.

Structure-fluorescence relationships in pyrrole appended o-carborane crystalline materials

Based on three rationally designed pyrrole-appended o-carborane derivatives,we present that fluores-cence properties of crystalline materials are highly dependent on intermolecular interaction and steric hinderance.Though the three molecules are similar in structure,single crystals of the three compounds showed obvious difference in molecular stacking and fluorescence behavior.Systematic studies indicate that fluorescence quantum yields,thermo-response as well as mechano-response are highly dependent on intermolecular interaction and steric hindrance.In the three crystalline materials,the CB-NMe crys-tals with weaker intermolecular interaction and looser molecular packing showed superior fluorescence quantum yield and temperature sensitivity.Accordingly,surface temperature detection strip with favor-able reversibility is prepared by doping CB-NMe into the polymer.In addition,the CB-NMe aggregates can be used for monitoring bovine serum albumin(BSA)denaturation,as temperature response of the aggregates can be reversed when co-assembled with BSA.