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1.
将改进小波神经网络与BP神经网络相结合,提出一种新的混级联神经网络结构,用于单扫描示波极谱信号的同时测定。通过对网络结构的优化和网络参数的调整,加快了训练速度,提高了预测的准确度。用该法对邻、间硝基氯苯混合样进行了预测,结果满意。对级联神经网络法与单一BP神经网络法的预测结果进行了比较,表明级联神经网络优于单一BP神经网络。  相似文献   

2.
在pH 6.5的0.3 mol·L-1氯化钾介质中,在电位值-0.71 V 及-0.74 V处可分别见到对硝基氯苯及邻硝基苯酚的灵敏极谱峰,可分别对此两种化合物进行测定,但因两者相互干扰不能在混合物中同时测定.将改进的小波神经网络与BP神经网络相结合,提出一种新的混级联神经网络结构,并用于单扫描示波极谱法同时测定对硝基氯苯和邻硝基苯酚.通过对网络结构的优化和网络参数的调整,加快了训练速度,提高了预测的准确度.该法用于混合样品中同时测定对硝基氯苯和邻硝基苯酚,其相对误差和回收率分别为3.76%,96.2%;4.05%,96.0%.  相似文献   

3.
建立了测定麻疹病毒抗体的酶免疫电化学分析法。其原理是在异相酶联免疫之后用极谱法检测酶促产物。本法采用小型三电极系统“DME-Pt-Ag/AgCl”直接与商品酶联板配套使用,简化了操作步骤。对测定麻疹抗体的合适条件以及灵敏度,特异性等作了考察。结果表明,本法特异性强,灵敏度高,检测范围宽,不受样品颜色、浊度、杂散光及酶联板自身光吸收不均一的影响;应用于测定三批共118份血清样品,阳性率分别为15%(6/40),62.5%(25/40)和31.58%(12/38),用46份样品对本法和ELISA作相关性检验,其相关性良好(γ=0.77.t_r=10.84,P<0.001,相关显著)。  相似文献   

4.
无味红霉素是一种广谱临床抗生素,其分析方法已见报道的有薄层分离、生物自显影法和分光光度法。本文首次研究了无味红霉素的单扫极谱测定法,方法灵敏度可达0.05μg/mL,应用于血清和片剂分析,结果令人满意。并对极谱波性质作了初步探讨。 1 实验部分  相似文献   

5.
示波催化极谱法测定钢中微量钼   总被引:1,自引:0,他引:1  
采用EGTA-丙二酸复合掩蔽体系,苯羟乙酸-氯酸盐催化体系,示波极谱法直接测定了多种合金钢中的微量钼,方法操作简单,结果可靠,灵敏度高。  相似文献   

6.
生物素的微分脉冲极谱行为及其测定   总被引:6,自引:2,他引:6  
用微分脉冲极谱法研究了生物素的电化学行为,用滴汞电极作工作电极,在01mol·L-1LiCl底液中,生物素的峰电位为-150V,生物素浓度在528~877μmol·L-1范围内与峰高呈线性关系。初步探讨了电极反应机理。该法应用于含生物素样品的分析,可以不经分离,直接测定,结果良好。  相似文献   

7.
用电化学方法研究邻苯三酚的自氧化机理   总被引:15,自引:0,他引:15  
高若梅  邹洪 《分析化学》1997,25(3):297-300
利用单扫示波极谱法研究了邻苯三酚的自氧化机理,依据多种电化学参数和紫外可见吸收光谱对主要极谱峰和吸收峰的变化规律作出合理解释,指出邻苯三酚自氧化过程存在多种电子转移历程,单扫示波极谱法可直接监测半醌和醌等中间和最终产物的变化。  相似文献   

8.
实验发现,在硫酸介质及加热下,痕量钼(Ⅵ)对硫酸联氨还原甲基红这一缓慢褪色反应具有强烈催化作用;甲基红在氢氮化钠介质中于-0.70V.SCE处产生一灵敏的示波极谱波。据此,本文采用固定时间法,用示波极谱法研究了利用这一新的指示反应催化测定钼的影响因素,建立了一个检出限和测定范围分别为0.8ng/mL和1.6~100ng/mL钼的催化反应-示波极谱法,并用于测定矿石和钢样中的钼。  相似文献   

9.
线性回归间接极谱络合滴定   总被引:2,自引:0,他引:2  
刘建华  林文如 《分析化学》1995,23(8):922-925
本文提出的方法是,根据一定的络合平衡和物料平衡,将间接极谱和线性回归应用于络合滴定,旨在扩大络合滴定的应用范围。文中对测定误差作了分析和计算,探讨了滴定点及权重选择问题。  相似文献   

10.
砷在1.5×10^-4mol/L Co-0.1mol/L KCNS-1%抗坏血酸-0.7mol/L Na2SO4-4×10^-3mol/L NaBr介质中产生一灵敏催化波,峰电位为-1.1V。采用微分脉冲极谱法研究了各项实验条件,建立了直接测定硫中微量砷的方法。该法简便快速,结果满意。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

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