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51.
Research in science and medicine is witnessing a massive increases in literature concerning extracellular vesicles (EVs). From a morphological point of view, EVs include extracellular vesicles of a micro and nano sizes. However, this simplistic classification does not consider both the source of EVs, including the cells and the species from which Evs are obtained, and the microenvironmental condition during EV production. These two factors are of crucial importance for the potential use of Evs as therapeutic agents. In fact, the choice of the most suitable Evs for drug delivery remains an open debate, inasmuch as the use of Evs of human origin may have at least two major problems: (i) autologous Evs from a patient may deliver dangerous molecules; and (ii) the production of EVs is also limited to cell factory conditions for large-scale industrial use. Recent literature, while limited to only a few papers, when compared to the papers on the use of human EVs, suggests that plant-derived nanovesicles (PDNV) may represent a valuable tool for extensive use in health care.  相似文献   
52.
以一种特定成分的有机硅为原料,采用溶胶-凝胶法,在硅基片上制备出用于光波导器件的薄膜.通过折射率和厚度测试及XPS成分测试验证了此薄膜具有较好的均匀性、厚度和光学特性,满足光波导器件的要求.分析了溶胶-凝胶法中常见的龟裂现象的原因以及采预防方法.利用这种薄膜结合微电子加工工艺制备出光波导器件阵列波导光栅.  相似文献   
53.
Incorporation of ions in the active layer of organic semiconductor devices may lead to attractive device properties like enhanced injection and improved carrier transport. In this paper, we investigate the effect of the salt concentration on the operation of light‐emitting electrochemical cells, using experiments and numerical calculations. The current density and light emission are shown to increase linearly with increasing ion concentration over a wide range of concentrations. The increasing current is accompanied by an ion redistribution, leading to a narrowing of the recombination zone. Hence, in absence of detrimental side reactions and doping‐related luminescence quenching, the ion concentration should be as high as possible.  相似文献   
54.
One-dimensional (1D) organic nanoribbons built on N-p-nitrophenylsalicylaldimine cadmium complex were synthesized via a facile solvothermal route. Scanning electron microscope images revealed that the as-synthesized products were ribbon like with widths of 500 nm,thicknesses of about 50nm, and lengthes up to several hundred micrometers. Fourier transform infrared spectrum was employed to characterize the structure. The conductivity of a bundle of nanoribbons was also measured,which showed that Schiff base cadmium nanoribbons had good photoconductive property. This work might enrich organic photoconductive materials and be applicable in nano photoswitch devices in the future.  相似文献   
55.
In this study we report first data on exfoliated graphitic nanoplatelets (xGnPs) as a sorbent for phenol removal and preliminary evaluated the ability of different type of natural organic matter (NOM) to effectively disperse exfoliated graphitic nanoplatelets.  相似文献   
56.
Highly dispersed,high performance Pt and PtRu catalysts,supported on multiwalled carbon nanotubes(CNTs),were prepared by a high pressure organic colloid method.The particle sizes of the active components were as small as 1.2 nm for Pt and 1.1 nm for PtRu,and the active Pt surface areas were 295 and 395 m2/g,respectively.The catalysts showed very high activities toward the anodic oxidation of methanol,evaluated by cyclic voltammetry,being up to 4 times higher than that of commercial Johnson Matthey Hispec 20...  相似文献   
57.
To understand the potential threat of volatile organic compounds (VOCs) to the health of residents living close to a heavily polluted river, this study investigated the species and the concentration of VOCs evaporating from a river and surveyed the health condition of the nearby residents. Air samples were taken seasonally at the upstream, midstream, and downstream water surfaces of the river, and at different locations at certain distances from the river. These samples were analyzed qualitatively and quantitatively through gas chromatography and electron capture detector (GC/ECD) for chlorinated organic compounds, and through gas chromatography and flame ionization detector (GC/FID) for ordinary hydrocarbons. The health data obtained from valid health questionnaires of 908 residents were analyzed through Statistical Package for Social Science (SPSS) software. Twenty-six species of VOCs were identified in the environment adjacent the river, many of which are carcinogenic or believed to be carcinogenic to humans. However, results of this study shows that the VOCs evaporating from the polluted river have not been definitively identified as a major factor of cancer in the residents. However, the risk of suffering from certain chronic diseases may increase in residents living less than 225 m away from the river due to the high levels of evaporated VOCs. Residents living less than 225 m away from the river and with nearby specific industries are 3.130 times more at risk of suffering from chronic diseases than those with no nearby specific industries.  相似文献   
58.
天然气净化厂硫磺回收及尾气处理装置尾气中有机硫含量对SO_2减排有重要影响。研究表明,硫磺回收装置的燃烧炉、催化反应器及尾气处理装置的加氢水解反应器中均会生成有机硫。对此,可通过减少酸气中烃类含量、提高燃烧炉温度、选择合适催化剂类型以及保持较高的加氢水解反应温度等措施,有效降低有机硫的生成量。同时,对于过程中生成的有机硫,应优化催化剂组合方式,在各级反应器中叠加水解,并保持加氢水解单元的高效转化,将进入灼烧炉的有机硫含量降至最低,从而实现生产装置尾气排放达标。  相似文献   
59.
研究页岩气的散失过程、散失能力及其控制因素对于揭示页岩气的成藏机理、指导页岩气的勘探选区等都具有重要的现实意义。为此,以四川盆地东南部及其盆缘转换带(以下简称渝东南盆缘转换带)下志留统龙马溪组页岩为例,通过现场解吸实验模拟页岩气散失过程,并借助X射线衍射分析、有机碳含量测试、低温氮气吸附实验、等温吸附实验、扫描电镜观察等室内研究手段,定性分析页岩气的散失过程,定量评价页岩气的散失能力,并在此基础上探讨影响页岩气散失能力的主控因素。研究结果表明:(1)该转换带龙马溪组上、下段页岩的页岩气散失过程存在着明显的差异,后者的散失能力明显低于前者;(2)页岩气散失能力主要由温度、压力及岩石属性等决定,其中温度、压力是最主要的外在因素;(3)有机质含量是决定页岩气散失能力的最主要内在控制因素,随有机质含量的增加,页岩比表面积增大、吸附能力增强,页岩气散失能力降低;(4)页岩气散失能力在一定程度上受到岩石矿物成分和孔隙结构的影响,石英含量、黄铁矿含量与散失能力呈负相关关系,长石含量与散失能力呈正相关关系,碳酸盐矿物含量和黏土矿物含量与散失能力之间的相关性不明显。  相似文献   
60.
To achieve semiconducting materials with high electron mobility in organic field‐effect transistors (OFETs), low‐lying energy levels (the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO)) and favorable molecular packing and ordering are two crucial factors. Here, it is reported that the incorporation of pyridine and selenophene into the backbone of a diketopyrrolopyrrole (DPP)‐based copolymer produces a high‐electron‐mobility semiconductor, PDPPy‐Se. Compared with analogous polymers based on other DPP derivatives and selenophene, PDPPy‐Se features a lower LUMO that can decrease the electron transfer barrier for more effective electron injection, and simultaneously a lower HOMO that, however, can increase the hole transfer barrier to suppress the hole injection. Combined with thermal annealing at 240 °C for thin film morphology optimization to achieve large‐scale crystallite domains with tight molecular packing for effective charge transport along the conducting channel, OFET devices fabricated with PDPPy‐Se exhibit an n‐type‐dominant performance with an electron mobility (μe) as high as 2.22 cm2 V?1 s?1 and a hole/electron mobility ratio (μhe) of 0.26. Overall, this study demonstrates a simple yet effective approach to boost the electron mobility in organic transistors by synergistic use of pyridine and selenophene in the backbone of a DPP‐based copolymer.  相似文献   
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