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21.
Meng Wang Weiyue Feng Junwen Shi Fang Zhang Bing Wang Motao Zhu BaiLi Yuliang Zhao Zhifang Chai 《Talanta》2007,71(5):2034-2039
A mild, efficient and convenient extraction method of using 2-mercaptoethanol contained extractant solution combined with an incubator shaker for determination of mercury species in biological samples by HPLC–ICP-MS has been developed. The effects of the concentration of 2-mercaptoethanol, the composition of the extractant solution and the shaking time on the efficiency of mercury extraction were evaluated. The optimization experiments indicated that the quantitative extraction of mercury species from biological samples could be achieved by using 0.1% (v/v) HCl, 0.1% (v/v) 2-mercapoethanol and 0.15% (m/v) KCl extractant solution in an incubator shaker for shaking overnight (about 12 h) at room temperature. The established method was validated by analysis of various biological certified reference materials, including NRCC DOLT-3 (dogfish liver), IAEA 436 (tuna fish), IAEA MA-B-3/TM (garfish filet), IAEA MA-M-2/TM (mussel tissue), GBW 08193 (bovine liver) and GBW 08572 (prawn). The analytical results of the reference materials were in good agreement with the certified or reference values of both methyl and total mercury, indicating that no distinguishable transformation between mercury species had occurred during the extraction and determination procedures. The limit of detection (LOD) for methyl (CH3Hg+) and inorganic mercury (Hg2+) by the method are both as 0.2 μg L−1. The relative standard deviation (R.S.D.s) for CH3Hg+ and Hg2+ are 3.0% and 5.8%, respectively. The advantages of the developed extraction method are that (1) it is easy to operate in HPLC–ICP-MS for mercury species determination since the extracted solution can be directly injected into the HPLC column without pH adjustment and (2) the memory effect of mercury in the ICP-MS measurement system can be reduced. 相似文献
22.
Minshou Zhao Xinbo Zhang Yujun Chai Changying Sun 《Research on Chemical Intermediates》2006,32(5):403-417
The structures and the electrochemical characteristics of La0.7−x
CexMg0.3Ni2.8Co0.5 (x = 0.1–0.5) alloy, Ti0.25−x
ZrxV0.35Cr0.1Ni0.3 (x = 0.05–0.15) alloy and AB3<x<5-type alloy, which are the representative examples of AB3-type alloy, solid solution alloy and non-AB5-type alloy, respectively, have been investigated, and the performances of MH-Ni battery in which AB3<x<5 type alloy is used as the negative electrode material are examined at relatively low temperature. 相似文献
23.
SOLAR SPECTRAL IRRADIANCE IN THE VISIBLE AND INFRARED REGIONS 总被引:1,自引:0,他引:1
Abstract— The analytical formulas previously developed for estimating the spectral irradiance reaching the ground in the ultraviolet are extended into the visible and infrared(350–3000 nm). This approach has two distinct features: (1) all physical inputs for calculating the direct irradiance are given in analytical form, and (2) the diffuse spectral irradiance (skylight) is calculated using dimensionless ratios which relate it to the direct irradiance. In common with other approaches, the global spectral irradiance for arbitrary ground reflectivity is calculated from the sum of the direct and diffuse spectral irradiances and a divisor which depends upon the ground and air spectral reflectivities. The global spectral irradiance on a tilted surface may also be calculated in terms of the above quantities and two angles. As in the case of the ultraviolet, the formulas presented are intended for photobiological applications. 相似文献
24.
Li Ting Chai Yang Zhou Li Wei Wei Wang Quan Rui Wang Feng Gang Tao 《中国化学快报》2007,18(12):1460-1462
Nation-Teflon bimembrane was used as an efficient support for the preparation and application of heterogeneous palladium catalysts.The supported palladium catalysts exhibit high activity and stability in the Suzuki cross-coupling of aryl bromides with arylboronic acids to afford the corresponding biaryls in good to excellent yields,and can be readily recovered and reused several times without significant loss of activity. 相似文献
25.
Macrocyclic Schiff‐base ligand, bisacetylaceton‐ethylenediimine (BAE) and its transition metal complexes M(BAE) (M = Cu2+, Ni2+) were synthesized. The complexes having characteristics of aromatic systems and well‐defined one‐dimensional structures, reacted with p‐phthaloyl chloride, to obtain polymer complexes. The complexes were characterized by elemental analysis, inductively coupled plasma (ICP), FT‐IR, and thermal analysis and show good thermal stability. ESR spectra analysis discovered that there are free radicals in the chain of polymers, indicating that a weak magnetic spin‐exchange interaction operates between the metal ions and free radicals. It is found that, as the bridging p‐phthaloyl group is able to propagate the magnetic exchange interaction, the polymer complexes show paramagnetic properties by measurement of temperature dependence of the magnetic property, and obey Curie–Weiss law. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
26.
In this paper, we investigate dual problems for nonconvex set-valued vector optimization via abstract subdifferential. We first introduce a generalized augmented Lagrangian function induced by a coupling vector-valued function for set-valued vector optimization problem and construct related set-valued dual map and dual optimization problem on the basic of weak efficiency, which used by the concepts of supremum and infimum of a set. We then establish the weak and strong duality results under this... 相似文献
27.
Zheng J. Maharaj C. Liu J. Chai H. Liu H. Dear J. P. 《Mechanics of Composite Materials》2022,58(1):125-140
Mechanics of Composite Materials - In this research, the maximum stress, Hashin, Puck, LaRC03, and Northwestern University (NU) criteria are analyzed based literature data, analytical results... 相似文献
28.
T. Sandrock T. Danger E. Heumann G. Huber B. H. T. Chai 《Applied physics. B, Lasers and optics》1994,58(2):149-151
We report, to our knowledge for the first time, Continuous Wave (CW) laser emission at room temperature of Pr:LiYF4 (Pr.YLF) at six wavelengths: 522, 545, 607, 639.5, 720 and 907.4 nm. The pump source was an argon-ion laser tuned to a wavelength of = 457.9 nm. The maximum output powers at 522 nm (3Pi 3H5) and 639.5 nm (3P0 3F2) were 144 and 266 mW, respectively. We also observed CW laser action of Pr:GdLiF4 (Pr: GLF) at = 639 nm and of Pr:KYF4 (Pr: KYF) at = 642.5 nm. 相似文献
29.
[reaction: see text] A novel cycloaldol approach to the isobenzofuran core common to many of the eunicellin diterpenes is described. The cycloaldol precursor was prepared by aldol addition of (S)-(+)-carvone and methacrolein followed by etherification to a glycolate ester. Chemoselective enolization of the glycolate ester led to the cycloaldol adduct in high yield and diastereoselectivity. An oxidative rearrangement-allylic diazene rearrangement sequence established the requisite cis ring fusion. 相似文献
30.
Z. F. Chai Q. F. Qian X. Q. Feng P. Q. Zhang N. Q. Liu W. Y. Feng M. X. Kuang H. Y. Wang Y. Z. Zhang 《Journal of Radioanalytical and Nuclear Chemistry》2004,259(1):153-156
The occupational health impact of atmospheric pollution on exposed workers at one iron and steel complex was studied by instrumental neutron activation analysis of workers' hair samples and medical examination. The experimental results indicate that there is a positive correlation between the high inhalation amounts of iron and other trace elements by the exposed workers and the symptom of their high blood pressure and hypoglycemia, which implies that the atmospheric environment polluted by iron and steel industry has an adverse health impact on the exposed workers. The measures to relieve and abate the occupational diseases caused by air-borne particulate matter should be taken 相似文献