苯甲酰氨基脲的合成及其阴离子识别

设计合成了N-(取代苯甲酰氨基)脲衍生物(取代基=p-OC2H5,H,p-Cl)1～3,应用吸收光谱法考察了受体分子与阴离子如CH 3 CO-2,F-,H 2 PO-4等的相互作用,考察了取代基对受体分子与阴离子亲合力和结合选择性的调控或改善能力.结果表明,该类受体分子与阴离子通过氢键形成阴离子配合物,乙腈中受体分子1对F-表现出极高的响应选择性.Job作图法表明1与F-的结合计量比为1∶1,1H NMR滴定结果为受体分子与阴离子间的氢键作用本质提供了直接证据,初步探讨了F-响应选择性的原因

Ga掺杂δ-Pu的密度泛函理论计算

&delta;-Pu为Pu的高温相,掺杂少量的Ga即可使其在室温下稳定存在.本文采用密度泛函理论方法,对不同掺杂量体系进行晶体结构和电子结构计算,主要包括体系的晶格常数、密度、形成能、态密度、电荷密度和Mulliken布居分析.结果表明：在研究范围内,Ga掺杂后,体系晶格常数降低,密度增大,6.25%（原子百分比,下同）掺杂量体系的稳定性高于3.125%和12.5%掺杂量的体系;Ga掺杂使得Pu周围体系电子的局域性增强,成键能力增强,揭示了Ga稳定&delta;-Pu的电子机制.Ga和Pu之间为金属键,发生的作用主要由Pu的7s、6p、6d和Ga的4s、4p轨道电子贡献,但这种成键作用相对较弱,使得掺杂体系可以保持原有的力学性能和机械加工性能.Ga对&delta;-Pu的稳定作用主要在于改善Pu原子的成键性能,而不是与Pu原子直接成键.</p

The emergence of a new qiaoxiang: Its development, influences, problems and countermeasures

本文剖析位于福建省内陆山区的明溪新侨乡形成、发展的原因和过程 ,尤其注重考察近年来各类出国人员对移出地形成的社会影响 ,剖析在国际劳动力人口空前大规模流动的背景下 ,应当如何化堵为疏 ,对新老侨乡业已自行建立的跨国网络进行有效利用与引导 ,促进我国丰富的劳动力资源从跨国劳务中找寻机遇 ,有序流动 ,拓展新时期侨务工作的社会基础 ,加速农村小康社会的建设发展This is an empirical report based on the authors' recent field research. After tracing the history of Mingxi new qiaoxiang in the last decade, this paper attempts to explore the factors that have initiated and shaped the transnational emigration wave in this inland mountainous area of Fujian. In particular, both positive and negative social influences have resulted from the emigrants on the above-mentioned sending society. It argues that in the current age of migration, it would be better to formalize and promote the peasants' self-made migration network instead of simplg trying to destory it. It is obvious that stopping migration is neither possible nor desirable

融合几何特征向量的三维人脸识别

针对现有识别方法在特征选择的局限性,借鉴人脸的特征,提出一种融合几何特征向量的三维人脸识别方法。该方法提取了人脸面部具有相当代表性的特征点,从而得到一个相对完整的几何特征向量组用于识别匹配工作。实验结果表明,该方法改进了识别算法,从而较好得提高了识别率

Observation on Marangoni convection induced by desorption in falling soap film

In gas-liquid mass transfer processes,Marangoni convection may occur due to the surface tension gradient produced by mass transfer near the interface.With a falling soap film tunnel and the Schlieren optical method,the Marangoni convection patterns along the film surface were observed directly in the desorption process of acetone from the falling soap film.The Schlieren images showed the regular roll convection in the thin falling soap film during the acetone desorption.The hydraulic characteristics were determined experimentally by measuring the variation of acetone concentration in the film and the surface tension of the soap liquid.The results show that the acetone concentration gradient vertical to the falling direction is very small because the thickness of the soap film is in the order of 10-6 m.The variation of acetone concentration along the falling film is large,so there is a significant surface tension gradient,resulting in the Marangoni roll convection.The experimental results and a qualitative analysis may be helpful to understand the mechanism of Marangoni convection near the interface in the mass transfer.国家自然科学基金项目(20606027)---

Monitoring of Inshore Aquaculture Cages Using Unmanned Aerial Vehicle

无人机(unmanned aerial vehicle,UAV)遥感具有高时效、机动灵活、高分辨率的特点,探索应用UAV遥感平台对沿海养殖区进行监测,实时掌握养殖发展动态,开展灾后应急监测,显然具有重要意义.利用UAV获取的CCD相机光谱信息,建立渔排监测指数,提出了渔排监测指数阈值快速提取算法;并针对渔排本身混合了水体和木筏2种目标物的特性,对提取结果进行图像闭合算子运算.在福建沿海古雷和可门港的实验结果表明,基于UAV获取的数据影像,利用渔排监测指数快速提取算法估算的渔排面积精度在两个区域分别达到98.9%和97.4%,与传统遥感分类方法——最大似然法相比,在同一计算平台上,计算速度提高5倍,无论精度或速度都可满足海洋与渔业管理部门在业务上的快速响应需求.此外应用UAV,以苏迪罗台风过后的三都澳海区为例,尝试开展了台风灾害造成的渔排损毁分析,初步推算出台风造成的渔排损毁面积比例.该研究表明利用UAV遥感可以为渔业管理提供有效的技术支持.Unmanned aerial vehicle( UAV) may provide a quick means to gather information of inshore aquaculture cages for the government to have an emergency response to events such as typhoons.Based on CCD imageries with 0. 1 meter resolution acquired with UAV platform and its spectral features,here we proposed a threshold method to quickly detect the distribution of aquaculture cages in two bays of southern Fujian.An identification accuracy of 98. 9% and 97. 4%,for Gulei and Kemen bays,respectively,was obtained.Meanwhile,the image processing time is reduced by 5 times,compared to the time needed using the widely accepted conventional approach-maximum likelihood method.In addition,a rough evaluation on the ruin extent of aquaculture cages by typhoon was also attempted,using UAV acquired imageries and satellite images.This study suggests that optical remote sensing with UAV holds promise for better management of inshore aquaculture activities.国家科技支撑计划(2013BAB04B01);; 厦门大学海洋科学基地科研训练及科研能力提高项目(J1210050);厦门大学大学生创新创业训练计划(201510384091

Effects of transfection with acidic fibroblast growth factor by electroporation on skeletal muscle satellite cells

背景:课题组早期研究表明体外一定剂量酸性成纤维细胞生长因子对骨骼肌卫星细胞增殖有促进作用。目的:进一步验证电穿孔转染酸性成纤维细胞生长因子基因对骨骼肌卫星细胞生长、增殖及分化的影响。方法:原代培养、纯化骨骼肌卫星细胞,将带有酸性成纤维细胞生长因子基因的质粒P SECTAg-gfP-A fgf通过电转染的方法转染大鼠骨骼肌卫星细胞,荧光显微镜观察绿色荧光蛋白的表达情况并计算转染率,以流式细胞仪分析转染后细胞周期,绘制细胞生长曲线,观察转染后肌管形成情况,WESTErn blOTIng检测酸性成纤维细胞生长因子基因的表达。结果与结论:1免疫细胞化学检测:骨骼肌肌动蛋白呈阳性表达。2转染效率:P SECTAg-A fgf质粒电转染12 H后即可看见散在发绿色荧光的卫星细胞,72-96 H达高峰,阳性表达率约90%。3细胞周期检测:电转染后S期所占的百分比明显多于未转染对照组(P<0.05)。4细胞生长曲线检测:电转染细胞接种后第3天进入对数生长期,第5天后开始减少。5分化能力观察:电转染组肌管较未转染对照组明显减少,老化细胞较少。6WESTErn-blOT:酸性成纤维细胞生长因子基因在转染骨骼肌卫星细胞中表达。结果表明,通过电穿孔法可以将酸性成纤维细胞生长因子基因转染进骨骼肌卫星细胞并获得高效持久的表达,并有促进骨骼肌卫星细胞增殖及抑制分化为肌管的作用。BACKGROUND: Previous studies have shown that a certain dose of acidic fibroblast growth factor can promote skeletal muscle satellite cell proliferation in vitro.OBJECTIVE: To investigate the effects of transfection with acidic fibroblast growth factor by electroporation on growth, proliferation and differentiation of skeletal muscle satellite cells.METHODS: Skeletal muscle satellite cells were cultured and purified, and then transfected with plasmid p Sectag-GFP-a FGF by electroporation.The expression of green fluorescent protein was observed under fluorescence microscope, and the transfection efficiency was calculated.After transfection, cell cycle was analyzed by flow cytometry to draw the growth curve of skeletal muscle satellite cells.Western blot assay was employed to measure protein level of acidic fibroblast growth factor.RESULTS AND CONCLUSION:(1) Immunocytochemistry detection: The skeletal muscle satellite cells were positive for a-sarcomeric actin.(2) Transfection efficiency: At 12 hours after transfection with p Sectag-a FGF, several cells showed green fluorescence, and the green fluorescent expression reached the peak at 72-96 hours after transfection with a positive rate of about 90%.(3) Cell cycle: After electrotransfection, the proportion of cells at S phase in the electroporation group was higher than that in the control group(P < 0.05).(4) Cell growth curve: At 3 days after electrotransfection, the cells entered logarithmic growth phase but the proliferation slowed down at 5 days.(5) Differentiation capacity: There were fewer myotubes and aging cells in the electroporation group than the control group.(6) Western blot assay: Acidic fibroblast growth factor protein was highly expressed in the cells transfected with target gene detected by western blot assay.These findings indicate that by using electroporation method, acidic fibroblast growth factor can be transferred into skeletal muscle satellite cells and have a high-efficiency and long-term expression, which can promote the proliferation of skeletal muscle satellite cells and inhibit formation of myotubes

Synthesis of N-Benzamidoureas and Its Anion Recognition

Three N-(substituted-benzamido)urea-based receptors (substituent=p-OC2H5, H, p-Cl) 1 similar to 3, were designed and synthesized. Their interactions with anions such as CH3CO2-, F-, H2PO4, ClO4-, Cl and Br- in acetonitrile were investigated by using absorption spectroscopy. H-1 NMR titrations and Job plots confirming that I : I hydrogen-bonding complexes were formed between the receptors and anions. Results showed that varying substituent could efficiently tune the hydrogen bonding interaction with anions and modulate the selectivity and sensitivity to anion recognition. Receptor 1 bearing an electron-donating substituent showed a highly selective recognition of a fluoride anion, which may result from the formation of an intramolecular seven-membered ring hydrogen bond in the receptor molecule that affords a suitable arrangement of the anion binding sites matching well for a fluoride anion

锂离子电池三元层状氧化物正极材料失效模式分析

镍钴锰三元层状氧化物(NCM)正极材料由于其优越的综合性能在动力/储能电池系统(ESS)领域得到广泛应用。虽然Ni含量的增加可提高三元材料的比容量及电池的能量密度,但相关电池体系的容量保持率和安全性将会变差。如何有效解决该矛盾是此类NCM电池所面临的关键问题。本文从NCM电池体系循环过程中常见的体相结构破坏和正极-电解液界面组成改变两方面失效现象出发,结合近年来国内外对NCM失效模式研究中所提出的新理论、方法、应用,从机械破坏、结构演变、电化学极化、化学副反应、正负极协同效应等多个角度对NCM材料的衰退机理提出见解,对指导电池用户合理制定充放电协议、缓解电动汽车(EV)里程焦虑乃至材料设计本身均有重要的指导及借鉴意义。国家重点研发计划资助（2018YFB0104400,2018YFB0905400