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AM-DEAM-AA共聚物的合成及性能研究 总被引:1,自引:0,他引:1
合成了丙烯酰胺(AM)、N,N-二乙基丙烯酰胺(DEAM)、丙烯酸(AA)的三元共聚物。研究了影响共聚反应的主要因素和共聚物溶液性能,通过IR、NMR、DSC和TG对共聚物进行了结构表征。结果表明,共聚物的玻璃化和热分解温度分别为173℃和240℃,共聚物溶液具有良好的抗剪切性、耐盐性和热稳定性 相似文献
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AM—DEAM—AA共聚物的合成及性能研究 总被引:4,自引:0,他引:4
合成了然酰胺,N,N-二乙基丙烯酰胺,丙烯酸的三元共聚物,研究了影响共聚反应的主要因素和共聚物溶液性能,通过IR、NMR、DSC和TG对共聚物进行结构表征,结果表明,共聚物的玻璃化和热分解温度分别为173℃,240℃共聚物溶液具有良好的抗剪切切性,耐盐性和热稳定性。 相似文献
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本研究了乳化剂(E)(1283,SDS和1283+SDS)对明胶/丙烯酸丁酯(Gel/BA)、明胶/丙烯腈(Gel/AN)明胶/(丙烯酸丁酯-珍烯腈)(Gel/(BN-AN)接枝共聚反应的影响,提示出了这三种乳论剂的使用对明胶拉枝共聚反应的影响规律。对于Gel/BA三种乳化剂均合适,对于Gel/AN,Gel/(BA-AN),1283或不加乳化剂较为合适,本还研究了在不用乳化剂的条件下,乳化时间 相似文献
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利用现有的抗体可变区晶体结构数据及抗人黑色素瘤细胞单抗可变区的氨基酸序列,在SGI图象工作站上,利用同源蛋白质结构预测的方法,建立了该抗体Fv部分的三维空间模型,并对其与配体神经节苷脂分子相互作用的可能模式进行了模拟研究。结果研究表明,抗体中的抗原结合部位包括由14个氨基酸组成的类似葫芦形的狭长口袋,其中的六个氨基酸参与了八对氢键的形成。GD2分子中的GalNAc及Gal上两上N-乙酰神经氨糖酸( 相似文献
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苯乙烯—丙烯腈—N—苯基马来酰亚胺乳液共聚物的热分析表征 总被引:5,自引:1,他引:4
通过乳液聚合的方法制备了苯乙烯-丙烯腈-N-苯基马来酰亚胺三元共聚物,由DSC、DMA及TG热分析方法对共聚物的性能进行了对比表征。实验结果表明,DMA方法能更好地表征N-PMI组分对共聚物耐热性能的影响,它一方面可以确定玻璃化的变化,另一方面可以测定材料模量的变化情况。 相似文献
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Jinsheng Liao Huazhong Huang Hangying You Xin Qiu Yong Li Bao Qiu He-Rui Wen 《Materials Research Bulletin》2010,45(9):1145-1149
NaGd(MoO4)2:Eu3+ (hereafter NGM:Eu) phosphors have been prepared by sol-gel method. The properties of the resulting phosphors are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL) spectra and decay curve. The excitation spectra of NGM:Eu phosphors are mainly attributed to O → Mo charge-transfer (CT) band at about 282 nm and some sharp lines of Eu3+ f-f transitions in near-UV and visible regions with two strong peaks at 395 and 465 nm, respectively. Under the 395 and 465 nm excitation, intense red emission peaked at 616 nm corresponding to 5D0 → 7F2 transition of Eu3+ are observed for 35 at.% NGM:Eu phosphors as the optimal doping concentration. The luminescence properties suggest that NGM:Eu phosphor may be regarded as a potential red phosphor candidate for near-UV and blue light-emitting diodes (LEDs). 相似文献
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Drew MS Finlayson GD 《Journal of the Optical Society of America. A, Optics, image science, and vision》2000,17(8):1361-1370
Spectral sharpening is a method for developing camera or other optical-device sensor functions that are more narrowband than those in hardware, by means of a linear transform of sensor functions. The utility of such a transform is that many computer vision and color-correction algorithms perform better in a sharpened space, and thus such a space can be used as an intermediate representation for carrying out calculations. In this paper we consider how one may sharpen sensor functions such that the transformed sensors are all positive. We show that constrained optimization can be used to produce positive sensors in two fundamentally different ways: by constraining the coefficients in the transform or by constraining the functions directly. In the former method, we prove that convexity can be used to constrain the solution exactly. In a sense, we are continuing the work of MacAdam and of Pearson and Yule, who formed positive combinations of the color-matching functions. However, the advantage of the spectral sharpening approach is that not only can we produce positive curves, but the process is "steerable" in that we can produce positive curves with as good or better properties for sharpening within a given set of sharpening intervals. At base, however, it is positive colors in the transformed space that are the prime objective. Therefore we also carry out sharpening of sensor curves governed not by positivity of the curves themselves but of colors resulting from them. Curves that result have negative lobes but generate positive colors. We find that this type of constrained sharpening generates the best results, which are almost as good as for unconstrained sharpening but without the penalty of negative colors. All methods discussed may be used with any number of sensors. 相似文献
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本文研究了一类混合型Lyapunov矩阵方程的对称正定解问题。首先将此方程转化为等价的含参矩阵方程,然后运用矩阵分解和紧凸集上不动点定理,给出了方程具有对称正定解的一些必要和充分条件:其次建立两种求方程对称正定解的参数迭代算法,分析了迭代的收敛性及参数的选取方法,并指出这两种算法的适应性和特点;数值算例表明上述算法的可行性和有效性,并对比出两种迭代的敛速。 相似文献
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非线性微分方程组边值问题多个正解的存在性 总被引:1,自引:0,他引:1
本文考虑了张力桥稳定性问题的数学模型,对相应的非线性微分方程组边值问题正解的存在性问题进行了研究.通过构造特殊的锥,在不同区间上利用锥拉伸和锥压缩不动点定理,给出了一类复合型非线性微分方程组边值问题一个或多个正解的存在性,并且给出几个例子说明本文定理的应用,从而有助于对实际工程中张力桥的稳定性问题的研究. 相似文献
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本文讨论了一类带有非线性边界条件的捕食-食饵模型,此模型比相应具有线性边界条件的模型具有更加广泛的应用价值。我们利用格林公式证明了一类特征值问题的所有特征值都是正的,利用局部分歧理论证明了模型正解的存在性,进一步,我们利用扰动理论建立了分歧解的渐近稳定性。为了支持和补充分析结果,我们最后利用Matlab软件进行了数值模拟。 相似文献
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高阶中立型差分方程正解的存在性和渐近性 总被引:8,自引:0,他引:8
研究了一类高阶中立型差分方程△^l(Xn-CnXn-m) PnXn-k=0,n=N,N 1,N 2……正解的存在性和渐近性。利用Krasnoselskii不动点定理,给出了该类方程存在有界最终正解及当n→ ∞时其解渐近趋于零的几个充分条件。 相似文献