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311.
It was found that the weak chemiluminescence produced from the reaction of polyhydroxy phenols with luminol in alkaline solution could be strongly enhanced by ferricyanide and ferrocyanide. Based on this found, a new flow injection chemiluminescence method is proposed for the determination of four polyhydroxy phenols: pyrogallol, phlorglucinol, quinol and resorcinol. The detection limits of the method are 0.03 μg ml−1 pyrogallol, 0.03 μg ml−1 phlorglucinol, 0.04 μg ml−1 quinol, and 0.02 μg ml−1 resorcinol. The possible mechanism of CL reactions is also discussed briefly. 相似文献
312.
原油三维荧光分析中猝灭现象辨析 总被引:5,自引:0,他引:5
研究了原油的三维荧光猝灭现象,指出浓度过高是原油产生荧光猝灭的主要原因,将会造成三维荧光等值线图畸变,致使定量分析数据失真,谱图特征变异,难以获取原油特征三维指纹图。提出了避免荧光猝灭的预试方法,并列出了不同类型原油的最佳测试浓度。 相似文献
313.
Lu Chengxun Feng Xinde Wang Chongqing Ll Dechang 《Journal of polymer science. Part A, Polymer chemistry》1980,18(8):2411-2422
Four typical bioactive esters of acrylic monomers, N-p-acryloxybenzoyloxysuccinimides, 3-ac-ryloxy-4-oxo-3,4-dihydro-1,2,3-benzotriazines, N-acryloxy-5-norbornene-2,3-dicarboximides, and I-p-acryloxybenzoyloxybenzotriazoles, were Synthesized and polymerized as reactive polymers. Twelve new monomers were prepared by coupling acrylic acid, methacrylic acid, p-acryloxybenzoic acid, or p-methacryloxybenzoic acid with four N-hydroxy compounds such as N-hydroxysuccinimide (HOSu), 3-hydroxy-4-oxo-3,4-dihydro-1,2,3-benzotriazine (HOObt), N-hydroxy-5-norbornene-2,3-dicarboximide (HONB), and I -hydroxybenzotriazole (HOBT) in the presence of dicyclohexylcarbodimide. All monomers polymerized readily in solution with azobisisobutyronitrile (AIBN) as free radical initiator. The resulting reactive polymers with reactive ? OSu, ? OObt, ? ONB, or ? OBT group on the side chain are equally reactive toward n-butylamine at room temperature in the formation of corresponding polyacrylamides. Reactive polymers were used to immobilizetrypsin. It has been found that poly(N-p-methacryloxybenzoyloxy-5-norbornene-2,3-dicarboximide)-trypsin matrix had high activity around three times that of the poly(N-methacryloxy-5-norbornene-dicarboximide)-trypsin matrix. It is proposed that this activity may be due to the presence of a long spacer arm with a hydrophobic and rigid benzene ring between the ligand and matrix. The reactive poly(N-p-methacryloxybenzoyloxysuccinimide-p-methacryloxybenzoic acid) copolymer was used to immobilize the serum protein. This immobilized protein was a hopeful bioactive solid immunoadsorbent. 相似文献
314.
Multivariate classification methods were used to evaluate data on the concentrations of eight metals in human senile lenses measured by atomic absorption spectrometry. Principal components analysis and hierarchical clustering separated senile cataract lenses, nuclei from cataract lenses, and normal lenses into three classes on the basis of the eight elements. Stepwise discriminant analysis was applied to give discriminant functions with five selected variables. Results provided by the linear learning machine method were also satisfactory; the k-nearest neighbour method was less useful. 相似文献
315.
以SiO2和Li2CO3为反应原料,采用高温固相法于不同温度下合成了一系列可在高温500~750 ℃之间直接吸收CO2的硅酸锂(Li4SiO4)材料。采用扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)分别观察和评价了合成材料的表面形貌与结构特征,用热重分析仪(TG)研究了硅酸锂材料吸收CO2的性能。实验结果表明,在750 ℃下煅烧6 h即可合成出吸收CO2性能良好的硅酸锂材料,在CO2气氛下,于700 ℃保持约15 min即可达到吸收平衡,其吸收量约达43%(wt)左右。与文献报道相比,材料的合成条件有所改善,材料吸收CO2的容量也有较大提高。 相似文献
316.
317.
The hydrothermal reaction of NaVO(3).H(2)O, barbituric acid, NH(2)NH(2).2HCl, H(3)PO(4), and H(2)O gave a novel heteropolyoxovanadate Na(6)[(P(V)O(4))V(V)(6)V(IV)(12)O(39)](2).H(3)PO(4).31H(2)O (1) and an unexpected phase Na(2)[C(12)H(6)N(6)O(9)].7H(2)O (2). The basic building blocks in 1 are the six-capped sphere-shaped heteropoly anion [(P(V)O(4))V(V)(6)V(IV)(12)O(39)](3-) with framework similar to that of the reported polyoxovanadates possessing [V(18)O(42)] clusters encapsulating VO(4) or other ions. These heterpoly anionic units are linked via V[bond]O[bond]V bridges into an interesting 3D straight-channel structure. The structure of 2 consists of novel organic anions ([C(12)H(6)N(6)O(9)](2-), 5,5-bis(2',4',6'-trioxopyrimidyl)barbital, representing the first oxidized barbituric acid trimer) linked via sodium ions into 1D hollow tubes with diameter of 4.49 x 6.86 A and further connected into a three-dimensional framework via hydrogen bonds. 相似文献
318.
319.
Using synthesized 8-hydroxy-2'-deoxyguanosine 3'-monophosphate as a marker, the 32P-postlabeling method was adapted with minimum modifications for the analysis of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) content in deoxyribonucleic acid (DNA). This method allows the analysis of one 8-OH-dG per 10(4) DNA nucleotides with only 10 pmoles of nucleotides required. The amounts of 8-OH-dG in DNA detected by the postlabeling method correlated well with the electrochemical detection method but were consistently lower. 相似文献
320.
C. X. Lu Qiang Li Jingqi Pan 《Journal of polymer science. Part A, Polymer chemistry》1985,23(12):3031-3044
Four novel semirigid poly(amide-ester)s having the same ordered amide-amide-ester-ester (-AAEE-) and the same or the different phenyl structure were synthesized from the various combination of active acylamide of benzotriazole (HBT) such as 1,1′-(isophthaloyl)bisbenzotriazole (IPBBT) and 1,1′-(terephthaloyl)bisbenzotriazole (PBBT) with diols such as N,N'-bis(2-hydroxyethyl)isophthamide (HEIPA) and N,N'-bis(2-hydroxyethyl)terephthamide (HEPTA) which prepared from the selective N-acylation of IPBBT or PBBT with aminoethanol in excellent yield at room temperature. Before the preparation of diol monomers, a model reaction of selective N-acylation was also completed from active monoacylamide of benzotriazole, 1-benzoylbenzotriazole with aminoethanol. The ordered structure of poly(amideester)s were characterized by infrared (IR) and NMR spectra. On the bases of different reactivity between selective N-acylation and O-acylation of active acylamide of benzotriazole, poly(amide-ester)s having the ordered AAEE and the same phenyl structure were also readily synthesized from the IPBBT or PBBT with aminoethanol under mild conditions by one-bath process. 相似文献