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合成了一系列水杨醛缩芳香胺席佛碱稀土配合物,研究了它们的红外光谱、紫外可见光谱及荧光光谱性质。与配体相比,配合物的红外特征键C=N吸收波数有减小趋势,紫外光谱中出现新的长波长吸收带,荧光光谱为属离子微扰配体发光。 相似文献
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在四(三苯基膦)钯(Pd(PPh3)4催化作用下,通过催化偶合法可合成5,8-二噻基-萘基喹喔啉(DThQx(ace))和3,6-二噻基-哒嗪(DThPD)两种新型噻吩衍生物,同时也可合成了4,7-二噻基-2,1,3-苯并噻二唑(DThB)和1,4-二噻基-苯(DThPh),上述化合物产率分别为75%,78%,82%和67%。用红外光谱、核磁共振谱、元素分析等方法进行了表征,并对噻吩与不同芳香环构成的衍生物的紫外-可见吸收光谱和荧光光谱进行了对比研究。这四种化合物的紫外-可见吸收光谱中分别在435,336,446,325 nm处有最大吸收波长。其中DThQx(ace)、DThB和DThPh的荧光光谱中分别在564,568 nm和384 nm处观察到荧光,而DThPD无荧光。 相似文献
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9,10-蒽-3,3′-双(1,3-戊二烯-2,4-二醇)的合成与荧光性质 总被引:1,自引:1,他引:1
合成了一种含蒽环的荧光性烯醇化合物——9,10-蒽-3,3′-双(1,3-戊二烯-2,4-二醇),采用核磁共振谱、电喷雾质谱、红外光谱、紫外可见光谱和荧光光谱对该化合物进行结构表征。 相似文献
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合成了一种新的阴离子受体化合物PySN,通过1H NMR对其进行了表征。受体分子结合不同阴离子的紫外-可见光谱和荧光发射光谱变化表明:在非质子性溶剂中,PySN可选择性识别和传感氟离子、醋酸根及磷酸二氢根离子。 相似文献
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壳聚糖支载有机荧光染料可在生理条件下改变其荧光特性,本文采用壳聚糖(CTS)支载有机荧光染料Cy3,利用红外光谱和热分析对产物进行了表征,研究了壳聚糖支载的荧光染料紫外吸收光谱和荧光光谱特性,结果表明,壳聚糖支载的荧光染料Cy3的紫外吸收特征峰的波长无明显变化,荧光强度明显增强,支载后的荧光染料光稳定性良好,初步细胞标记实验显示,壳聚糖支载后的Cy3染料对脑胶质瘤细胞具有良好的亲和性,并能穿透细胞膜且发出明显荧光。 相似文献
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顶空固相微萃取对新疆麻黄挥发成分的分析 总被引:1,自引:0,他引:1
用顶空固相微萃取法分析了新疆地产野生蓝麻黄、中麻黄和木贼麻黄的挥发成分,共鉴定出167种化学成分,测定了各成分的相对质量分数并进行了比较,发现这3种麻黄草中所含的挥发成分有显著差异。其中,从蓝麻黄中鉴定出97种化合物,烯烃类化合物为其主要成分,占总峰面积的68.59%,含量最多的化合物是β-月桂烯,占总峰面积的28.10%;从中麻黄中鉴定出68种化合物,烯烃类化合物为其主要成分,占总峰面积的55.97%,含量最多的化合物是β-月桂烯,占总峰面积的25.42%;从木贼麻黄中鉴定出69种化合物,烯烃类化合物为其主要成分,占总峰面积的54.05%,含量最多的化合物是(1S,5S)-2(10)-蒎烯,占总峰面积的32.73%。 相似文献
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Orientation factor and number of fibers at failure plane in ring-type steel fiber reinforced concrete 总被引:1,自引:0,他引:1
Considering the probabilistic distributions of fibers in ring-type steel fiber reinforced concrete, the orientation factor and the number of ring-type steel fibers crossing the failure plane were theoretically derived as a function of fiber geometry, specimen dimensions, and fiber volume fraction. A total number of 24 specimens were tested incorporating different fiber types, specimen geometry, and fiber volume fractions of 0.2% and 0.4%: 5 beams and 5 panels containing straight steel fibers; and 6 beams and 8 panels containing ring-type steel fibers. Measurements were made to assess the number of fibers at fractured surfaces of steel fiber reinforced concrete. The developed theoretical expressions reasonably predicted the orientation factor and the number of ring-type steel fibers at failure plane: the average and the standard deviation for the ratios of the test to theory were 1.03 and 0.26, respectively. Theoretical investigations and comparisons were made for the values of orientation factor and the number of fibers at failure plane for straight steel fibers and ring-type steel fibers. 相似文献
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在有机溶剂中以维生素E和琥珀酸酐为底物在脂肪酶的催化下合成了维生素E琥珀酸酯。首先对酶促反应的脂肪酶、反应介质和反应温度进行了考察,在所选的几种脂肪酶中,假丝酵母脂肪酶(Candidasp.)的催化活性最好;叔丁醇和DMSO组成的混合溶剂(体积比为2∶3)为最合适的反应介质;30℃为适宜的反应温度。并采用Box-Behnken实验设计和响应面因子分析法对底物摩尔比等其他反应条件进行了优化。维生素E琥珀酸酯最优反应条件为:维生素E浓度0.26mmol.ml-1,维生素E和琥珀酸酐摩尔比1∶5,在5ml叔丁醇和DMSO混合溶剂(体积比为2∶3)中,30℃下在0.02gCandidasp.脂肪酶的催化下反应71h,维生素E琥珀酸酯产率达到98.71%。 相似文献
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《Ceramics International》2019,45(11):14214-14222
The potential of electrophoretic deposition of ceramic particles for additive manufacturing of 3D structures is investigated. A custom-made test setup is constructed using a hollow electrode for the supply of a ceramic suspension and a tip c electrode for focused deposition of particles on the surface of a membrane. Parameters like voltage, electrode distance, suspension flow rate, etc. are systematically varied to study their impact on the deposition yield and the morphology of the deposited structures. Experimental work is supported by computer simulations on the electrical field distribution within the electrode area. Although detrimental phenomena like electrohydrodynamic effects occur, we have shown that the technique offers opportunities for future 3D printing of ceramics. 相似文献
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Pro/ENGINEER在塑料模具设计中的应用 总被引:1,自引:1,他引:0
以摄像机上盖模具设计为实例,介绍了Pro/ENGINEER软件在塑料模具设计中的应用。使用Pro/ENGINEER软件可大大缩短设计和制造周期,提高产品设计准确性,降低设计成本。 相似文献
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Vitamin E succinate was synthesized in organic solvents using a modified Novozym-435 as catalyst.In order to improve the catalytic performance of Novozym-435,the enzyme was modified using acetic anhydride, propionic anhydride and succinic anhydride separately.We found that both the hydrolytic activity and the thermal stability of the modified Novozym-435 were enhanced compared with the unmodified enzyme.The modified Novozym-435 catalysts were used to synthesize the succinate derivative of vitamin E.Compared with the native Novozym-435,the catalytic activity of the modified novozym-435 in promoting the synthesis of vitamin E succinate was dramatically increased,with the novozym-435 modified with succinic anhydride(N435-S)as the most active catalyst.Conditions for the synthesis of vitamin E succinate were also optimized.A mixture of tert-butanol and DMSO(volume ratio of 2︰3)was the most suitable medium for the reaction,whereas the appropriate molar ratio of vitamin E to succinic anhydride and reaction temperature were 1︰5 and 40°C,respectively.Under these reaction conditions,the yield of vitamin E succinate reached 94.4%.N435-S could be reused for five batches. 相似文献
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