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11.
多波长线性回归紫外吸光光度法同时测定炼油厂污水中苯酚和苯胺 总被引:2,自引:0,他引:2
提出用多波长线性回归紫外吸光光度法同时测定炼油厂污水中的苯酚和苯胺.方法省去了萃取、蒸馏、显色等步骤,操作简单.对合成水样进行测定,相对标准偏差≤4.57%,相对误差≤±2.3%.对炼油厂水样进行测定并进行加标回收试验,苯酚和苯胶的回收率分别为99.4%~103.0%和97.2%~104.0%,结果良好.苯酚和苯胶的最低检出限分别为0.010和0.048μg·ml~(-1). 相似文献
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The direct and regioselective N-alkylation of amino-azoles to the corresponding 2-N-(alkylamino)azoles using various alcohols as alkylating agents with good to excellent yields has been accomplished by an iridium complex/base system. 相似文献
13.
X Liu H Nan W Sun Q Zhang M Zhan L Zou Z Xie X Li C Lu Y Cheng 《Dalton transactions (Cambridge, England : 2003)》2012,41(34):10199-10210
Heteroleptic neutral mononuclear cuprous complexes with dipyrrin derivatives and phosphine mixed-ligands including 1,3,7,9-tetramethyldipyrrin (1), 5-phenyl-1,3,7,9-tetramethyldipyrrin (2), 2,8-dibromo-1,3,7,9-tetramethyldipyrrin (3), 1,9-dichloro-5-phenyldipyrrin (4), 1,9-dibromo-5-phenyldipyrrin (5), 5-pentafluorophenyl-1,3,7,9-tetramethyldipyrrin (6) and 1,5,9-triphenyldipyrrin (7) have been synthesized and fully characterized. The central Cu(i) atoms of these complexes in general formulas of Cu(1-6)(PPh(3))(2) (1a-6a) and Cu(1-6)(DPEphos) (1b-6b) [DPEphos = bis(2-diphenylphosphinophenyl)ether] all exhibit a pseudo-tetrahedral geometry, while complex Cu(7)(PPh(3)) (7a) is tricoordinated in a pyramidal conformation due to the large steric hindrance of ligand 7. The oxidation potentials assigned to oxidations of Cu(i)-Cu(ii) are extraordinarily low in the range of 0.36-1.02 V vs. Ag/AgCl compared with traditional [Cu(phen)(PP)](+) analogues. Their emission maxima range from 495 to 595 nm in dichloromethane at room temperature with quantum yields of 0.05-4.03% and lifetimes on the order of nanoseconds. Unlike the characteristic MLCT emission in cationic Cu(i) complexes, the emissions are assigned to the dipyrrin-centered intraligand charge transition (ILCT) based on the fact that the increased conjugation within the dipyrrinato anion leads to a weaker metal-ligand interaction, thus preventing the mixing of π orbitals of ligand and 3d orbitals of Cu(i) atom. This conclusion is also supported by electrochemical data and theoretical calculations. 相似文献
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基于传统抛光的亚表面损伤层厚度,进行磁流变去除亚表面损伤层的实验以便验证在该加工方式下对元件中频误差的影响。计算机模拟结果及实验数据表明:磁流变加工的走刀间距会引起中频误差评价指标PSD曲线出现对应频率的峰值;抛光斑的不稳定性会引起PSD曲线出现不确定的次主峰;去除深度与PSD曲线峰值之间有近似的线性关系。采用磁流变作为亚表面损伤层的去除手段,元件的中频误差质量受加工参数影响很大。如果前级加工不佳导致留下的亚表面损伤层较深,用磁流变加工进行去除时会造成中频误差质量超过限定指标。1 相似文献
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悬浮液进样-火焰原子吸收光谱法测定玉米面中的锌和铁 总被引:7,自引:0,他引:7
本文提出一种悬浮液进样-火焰原子吸收光谱法测定玉米面中锌、铁的新方法.将玉米面悬浮于琼脂胶体中,直接喷入空气-乙炔火焰中,用标准加入法测定,测定结果与灰化法一致.方法简便、快速. 相似文献
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悬浮液进样火焰原子吸收光谱法测定豆米类粮食中镁 总被引:8,自引:2,他引:6
将样品磨细配制成悬浮液,并对悬浮剂的选择及化学干扰的消除进行了考查。为消除化学干扰,取适量悬浮液,加入La3+溶液制成试液。将试液喷入空气-乙炔火焰,以空白溶液为参比,用工作曲线法进行测定。测定结果与灰化法一致,相对误差小于±1.3%。方法简便、快速、准确。 相似文献
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基于最小二乘迭代的多表面干涉条纹分析 总被引:1,自引:1,他引:0
为了准确地测量透射平行平板,提出了基于最小二乘迭代的多表面干涉条纹分析方法.依据波长调谐相移的原理,通过最小二乘迭代准确地求得每组双表面干涉条纹的实际相移值.从而准确地提取平板前后表面面形及厚度变化等信息.模拟计算结果表明.当相移值有微小偏差(小于0.2 rad)时,通过10次迭代后求得相位的峰值(PV)误差为0.005 rad,均方根(RMS)误差为0.002 rad,而相应Okada算法的PV误差为0.512 tad.RMS误差为0.103 rad.实验结果验证了该箅法的有效性. 相似文献
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Three-dimensional fractures of different fractal dimensions have been constructed with successive random addition algorithm,
the applicability of various dimension determination methods at nanometer scale has been studied. As to the metallic fractures,
owing to the limited number of slit islands in a slit plane or limited datum number at nanometer scale, it is difficult to
use the area-perimeter method or power spectrum method to determine the fractal dimension. Simulation indicates that box-counting
method can be used to determine the fractal dimension at nanometer scale. The dimensions of fractures of valve steel 5Cr21Mn9Ni4N
have been determined with STM. Results confirmed that fractal dimension varies with direction at nanometer scale. Our study
revealed that, as to theoretical profiles, the dependence of frsctal dimension with direction is simply owing to the limited
data set number, i.e. the effect of boundaries. However, the dependence of fractal dimension with direction at nanometer scale
in real metallic fractures is correlated to the intrinsic characteristics of the materials in addition to the effect of boundaries.
The relationship of fractal dimensions with the mechanical properties of materials at macrometer scale also exists at nanometer
scale.
Project supported by the National Natural Science Foundation of China (Grant Nos. 59771050 and 59872004) and the Foundation
Fund of Ministry of Metallurgical Industry. 相似文献