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111.
以1-氯戊烷和N-甲基咪唑为原料合成了室温离子液体1-戊基-3-甲基咪唑四氟硼酸盐(PMIMBF4)和六氟磷酸盐(PMIMPF6),通过考察各种影响因素对中间产物氯代咪唑盐(PMIMCl)的影响得出合成1-戊基3-甲基咪唑离子液体的最佳条件为:原料N-甲基咪唑与1-氯戊烷的投料比为1.2∶1,反应温度为70-75℃,反应时间为24 h。最终产物的收率为92%-94%。产物结构用FT-IR和1HNMR光谱进行表征。 相似文献
112.
Song Shen Marhaba Mamat Shengchang Zhang Jin Cao Zachary D. Hood Legna Figueroa‐Cosme Younan Xia 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(36)
As a solid precursor to O2 and hydrogen peroxide (H2O2), calcium peroxide (CaO2) has found widespread use in applications related to disinfection and contaminant degradation. The lack of uniform nanoparticles, however, greatly limits the potential use of this material in other applications related to medicine. Here, a new route to the facile synthesis of CaO2 nanocrystals and their spherical aggregates with uniform, controllable sizes is reported. The synthesis involves the reaction between CaCl2 and H2O2 to generate CaO2 primary nanocrystals of 2–15 nm in size in ethanol, followed by their aggregation into uniform, spherical particles with the aid of poly(vinyl pyrrolidone) (PVP). The average diameter of the spherical aggregates can be easily tuned in the range of 15–100 nm by varying the concentrations of CaCl2 and/or PVP. For the spherical aggregates with a smaller size, they release H2O2 and O2 more quickly when exposed to water, resulting in superior antimicrobial activity. This study not only demonstrates a new route to the synthesis of uniform CaO2 nanocrystals and their spherical aggregates but also offers a promising bacteriostatic agent with biodegradability. 相似文献
113.
提出了文物保护工程中确定壁画地杖层空腔区域的一种新方法——声波检测方法。该方法是以人工激振的方法向介质发射声波,在一定的空间距离上接收介质物理特性调制的声波,通过观测和分析声波在不同介质中的传播速度,可以确定地杖层的空腔区域。从而为壁画文物保护工程的设计提供可靠的地质资料。因此,该方法具有一定的使用价值。 相似文献
114.
丁基磺酸纤维素醚减水剂的制备及其减水机理 总被引:1,自引:0,他引:1
以纤维素棉桨粕和1,4-丁烷磺内酯(BS)为原料合成了丁基磺酸纤维素醚减水剂(SBC)。采用红外光谱(FTIR)、13C 固体碳谱(13 CP MAS)、扫描电镜(SEM)、X衍射(XRD)等对产品结构进行了表征,并考察了纤维素聚合度、原料配比、反应温度、反应时间等合成工艺参数对SBC减水剂减水性能的影响。从丁基磺酸纤维素醚减水剂水溶液的表面张力和水-SBC-水泥体系的ζ电位等方面研究了SBC减水剂的减水机理。研究结果表明:SBC减水剂几乎不改变水的表面张力,它们在气-液界面的取向能力很小,对混凝土没有引气作用;SBC减水剂在水泥颗粒表面吸附的结果,使水泥颗粒表面带有相同电荷而相互排斥造成水泥颗粒的分散,从而出现减水效果。 相似文献
115.
通过研究纤维素氨基甲酸酯(CC)溶液中CC与NaOH配比(质量比)、溶液纺前处理时间及温度、纺丝凝固浴及再生浴的组成和温度对纤维素氨基甲酸酯溶液可纺性及其纤维性能的影响,得到湿纺工艺制备纤维素氨基甲酸酯纤维的最佳纺丝工艺条件.结果表明:配制CC质量分数为7%,CC与NaOH质量比为1的纤维素氨基甲酸酯的氢氧化钠溶液,在15℃ 以下进行纺前处理10~12h,溶液可纺性良好.这种溶液在温度为40℃ 的含H2SO4(150g /L)、Na2SO4(200g /L)、AI2(SO4)3(50g /L)的凝固浴中成形后,在温度为85℃ 、质量分数为1%的氢氧化钠水溶液中再生,可得到具有一定强度及伸长率的再生纤维素纤维. 相似文献
116.
以棉浆粕为基材,硝酸铈铵/HNO3为引发剂,甲基丙烯酸丁酯(BMA)为接枝单体,N ,N'-亚甲基双丙烯酰胺为交联剂,采用悬浮震荡接枝聚合反应制备了纤维素基吸油材料。采用红外光谱、X射线衍射、扫描电镜、热重分析、差示量热等手段对产物结构进行了表征,考察了棉浆粕的引发及其后的接枝聚合反应,得到最佳工艺条件为:采用含有铈离子的0.15 mol/L的HNO3水溶液在45 ℃下将棉浆粕活化处理2.5 h后,在HNO3水溶液及交联剂存在下,与BMA发生接枝聚合反应;反应配比为纤维素/引发剂/单体/交联剂=1/0.03/1.5/0.03,聚合反应温度为50 ℃,反应时间为24 h。所得纤维素与BMA的接枝共聚物有较高的接枝率及理想的吸油性能。 相似文献
117.
Muthukaruppan Karthigayan Mohd Rizon Mohamed Juhari Ramachandran Nagarajan Masanori Sugisaka Sazali Yaacob Mohd Rozailan Mamat Hazry Desa 《Artificial Life and Robotics》2007,11(2):197-203
In this article, two subjects, one South East Asian (SEA) and the other Japanese, are considered for face emotion recognition
using a genetic algorithm (GA). The parameters relating the face emotions in each case are entirely different. All six universally
accepted emotions and one neutral are considered for each subject. Eyes and lips are usually considered as the features for
recognizing emotions. This paper has two parts. The first part investigates a set of image processing methods suitable for
recognizing face emotion. The acquired images have gone through a few preprocessing methods such as gray-scale, histogram
equalization, and filtering. The edge detection has to be sufficiently successful even when the light intensity is uneven.
So, to overcome this problem, the histogram-equalized image has been split into two regions of interest (ROI): the eye and
lip regions. The two regions have been applied with the same preprocessing methods, but with different threshold values. It
was found that the Sobel edge detection method performed very well in segmenting the image. Three feature extraction methods
are considered, and their respective performances are compared. The method which is fastest in extracting eye features is
adopted. The second part of the paper discusses the way to recognize emotions from eye features alone. Observation of various
emotions of the two subjects lead to an unique eye characteristic, that is, the eye exhibits ellipses of different parameters
in each emotion. The GA is adopted to optimize the ellipse characteristics of the eye features in each emotion based on an
ellipse-based fitness function. This has shown successful emotion classifications, and a comparison is made on the emotions
of each subject. 相似文献
118.
Dr. Constantin Mamat Dr. Birgit Mosch Christin Neuber Prof. Dr. Martin Köckerling Dr. Ralf Bergmann Prof. Dr. Jens Pietzsch 《ChemMedChem》2012,7(11):1991-2003
Members of the Eph receptor tyrosine kinase family play essential roles in the pathogenesis of cancer and are therefore promising candidates for molecular imaging by positron emission tomography (PET), for example. In this regard, radiochemical access to novel PET radiotracers derived from potent inhibitors that target the EphB4 kinase domain and which bear a benzodioxolylpyrimidine structural motif was developed. A synthetic route was established for a new fluorine‐18‐containing radiotracer and for the desired precursor based on a high‐affinity benzodioxolylpyrimidine receptor tyrosine kinase inhibitor lead structure. The radiotracer [18F] 15 was obtained in 16 % radiochemical yield with a specific activity of ~7 GBq μmol?1 and >95 % radiochemical purity. Due to the implication of EphB4, particularly in the progression, angiogenesis, and metastasis of melanoma, EphB4‐overexpressing human melanoma cells were generated and used as a novel in vitro model for radiopharmacological evaluation of the radiotracer. We demonstrate that the corresponding non‐radioactive reference compound regained its functionality as an inhibitor for both EphB4 receptor tyrosine kinase and Src kinase. EphB4 was significantly inhibited at compound concentrations >1 μM . Cellular uptake studies with [18F] 15 revealed substantial uptake in both EphB4‐overexpressing and control cells. Moreover, NMRI nu/nu mice bearing both EphB4‐overexpressing tumors and control tumors were used for radiopharmacological characterization by biodistribution studies ex vivo and by dynamic small‐animal PET experiments in vivo. Despite the high metabolic stability of the novel radiotracer observed in vivo, no substantial binding or accumulation in EphB4‐overexpressing and control tumors was observed. Nevertheless, we point out that the approach presented herein gives convenient access to novel 18F‐labeled benzodioxolylpyrimidines and is a promising strategy for the further development of novel radiotracers for imaging Eph receptor tyrosine kinases in cancer. 相似文献
119.
120.
Through cross-linking modification of poly(o-phenylenediamine) (PoPD) to increase the adsorption active sites, the Cu2+ adsorption capacity of PoPD was improved significantly. According to FT-IR, XRD, SEM and BET results, both PoPD and the cross-linked PoPD had porous or surface-adhesive porous morphology with a typical mesoporous character, the specific surface area of the latter was increased obviously from the former. Both of them showed excellent Cu2+ adsorption capabilities with the maximum adsorption qexpmax of 76.51 and 85.49 mg·g−1, and the corresponding removal ratios of 60.21% and 68.39%, respectively. The adsorption capacity was increased to its 1.54 times with pentaerythritol tris[3-(1-aziridinyl)propionate] (cross-linking agent-III) as cross-linking agent at pH = 5 and 25°C. Because temperature could affect the adsorption behavior of materials and the adsorption process is endothermic with ΔG < 0, the process should be accompanied by spontaneous chemical changes. The XRD, SEM–EDX mapping and XPS results showed that Cu2+ was successfully removed from the aqueous solution. Additionally, the adsorption was mainly based on the cation-π interaction and the formation of Cu-N bonds. 相似文献