全文获取类型
收费全文 | 61篇 |
免费 | 2篇 |
国内免费 | 6篇 |
专业分类
化学 | 47篇 |
综合类 | 1篇 |
数学 | 1篇 |
物理学 | 20篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 3篇 |
2009年 | 2篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有69条查询结果,搜索用时 78 毫秒
11.
John Jacob 《Journal of magnetism and magnetic materials》2010,322(6):614-28
In the present work, we have synthesized nanostructured hematite samples using chemical precipitation method. The crystal structure and the grain size of the samples were studied using XRD. The zero field cooled and field cooled magnetization curves of the samples were recorded in the temperature range from 300 to 10 K. The variations of Morin transition temperature and blocking temperature with the grain size of the samples were investigated. The hysterics curves of the samples were recorded and the samples showed a superparamagnetic nature at room temperature whereas, at 10 K the samples showed open hysteresis curves. The sample with smaller grain size showed higher value of coercivity compared to samples with larger grain size. Mössbauer spectra of the samples were recorded and the grain size dependence on Mössbauer parameters was investigated. 相似文献
12.
A poly (tetrafluroethylene)-deoxyribonucleate acid (PTFE-DNA) film-modified glassy carbon electrode (GCE) has been fabricated. The electrochemical oxidation behaviors of morin as well as its interaction with DNA have been studied at PTFE-DNA film-modified GCE and bare GCE by electrochemical methods. This modified electrode shows an enhanced effectiveness towards the oxidation of morin. Importantly, as to the interaction between morin and DNA in solution, characteristic parameters such as the binding stoichiometry and association equilibrium constant according to the Hill model for cooperative binding have been determined on the basis of linear sweep voltammetry and chronocoulometry. 相似文献
13.
在0.1mol/L(pH=4.7)的HAc NaAc缓冲溶液中,用L 半胱氨酸自组装膜修饰金电极对桑色素的电化学行为进行了初步的研究,考察了修饰时间、富集时间、富集电位、扫描速度、表面活性剂、金属离子等因素对其电化学行为的影响。研究发现,桑色素在0.44V(vs.SCE)左右产生一不可逆的氧化峰。该氧化峰电流与桑色素浓度在5×10-6~2×10-4mol/L范围内呈线性关系(相关系数r=0.9989),检出限为2×10-6mol/L,这比用裸金电极测试降低一个数量级。同时发现,十六烷基三甲基溴化铵(CTAB)对氧化峰电流有一定的增敏作用。该峰且随Pb2+浓度增大而线性增高,因此可用于Pb2+的测定。 相似文献
14.
Xiaojun Zou Yuemei Cui Xiangbing Zhu Zheng Hu Xijun Chang 《Journal of Sol-Gel Science and Technology》2009,50(1):35-43
Morin was successful as a chemical modifier to improve the reactivity of the nanometer SiO2 surface in terms of selective binding and extraction of heavy metal ions. This new functionalized nanometer SiO2 (nanometer SiO2-morin) was used as an effective sorbent for the solid-phase extraction (SPE) of Cd(II), Cu(II), Ni(II), Pb(II), Zn(II) in
solutions prior to its determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions
for effective adsorption of trace levels of metal ions were optimized with respect to different experimental parameters using
static and dynamic procedures in detail. The pH 4.0 was chosen as the optimum pH value for the separation of metal ions on
the newly sorbent. Complete elution of the adsorbed metal ions from the nanometer SiO2-morin was carried out using 2.0 mL of 0.5 mol L−1 of HCl. Common coexisting ions did not interfere with the separation and determination at pH 4.0. The maximum static adsorption
capacity of the sorbent at optimum conditions was found to be 22.36, 36.8, 40.37, 33.21 and 25.99 mg metal/g SiO2-morin for Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II), respectively. The time for 95% sorption for Cu(II) and Ni(II) and 70%
sorption for Cd(II), Pb(II) and Zn(II) was less than 2 min. The relative standard deviation (RSD) of the method under optimum
conditions was lower than 5.0% (n = 11). The procedure was validated by analyzing the certified reference river sediment material (GBW 08301, China), the results
obtained were in good agreement with standard values. The nanometer SiO2-morin was successfully employed in the separation and preconcentration of trace Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II)
from the biological and natural water samples yielding 75-folds concentration factor. 相似文献
15.
桑色素是桑枝中的主要成分之一,属黄酮类化合物。该化合物是一种天然的生物活性物质,在自然界分布广泛,具有祛风湿、通血络、消浮肿和抗氧化等多种药理作用。同时,桑色素可与多种金属离子形成配合物作为配体进行分析。目前,有关桑色素的电化学行为及分析应用方法见报道的有高效 相似文献
16.
Hongzhen Lian Danni Li Sizhu Mei Xiaojiang Wu Xiancong Tao Yijun Chen Lemei Dai Ning Gan Liching Tian 《Analytica chimica acta》2004,511(1):25-31
A novel strategy for the speciation of aluminum has been developed by fluorometry using selective analytical reagents under different pH conditions, which is based on the measurement of the complexation ability of Al for analytical reagents and native organic matters. With Eriochrome Blue Black R, labile monomeric Al and total monomeric Al fractions are determined at pH 4.5 and pH 8.0, respectively. With morin only the labile monomeric Al is determined at pH 4.0, while with 8-hydroxyquinoline the total monomeric Al is determined at pH 5.5. So, acid soluble Al fraction is obtained indirectly. This method is successfully applied to the fractionation of Al in natural waters. The results well agree with those obtained by Driscoll’s 8-hydroxyquinoline/cation-exchange protocol. This fluorometric method possesses some advantages such as high sensitivity, easy manipulation, no separation step and less time-consuming. 相似文献
17.
18.
Cuiling Ren Jinhua Li Jiefang Sun Xingguo Chen Zhide Hu Desheng Xue 《Journal of luminescence》2010,130(1):65-69
In this paper, a new kind of fluorescent nanomaterial with morin modified alumina core and silica shell was prepared. Samples were characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), photoluminescent (PL) spectroscopy and fluorescence microscope. TEM results indicated that this material could be synthesized in nanometer range. PL spectra suggested that this new synthesized material was photostable and it showed nearly no dye leakage. This was because the dye molecules could form stable complex with the reactive aluminum cations on the surfaces of the alumina particles. The excitation and emission maxima of this new luminescent material were located at 420 and 493 nm, respectively. This new kind of luminescent nanomaterial was prepared by morin, AlCl3 and tetraethyl orthosilicate, which was very important for the large-scale and economic preparation luminescent nanoparticles because these precursors were inexpensive and the preparation process was convenient. 相似文献
19.
桑色素极谱行为的研究 总被引:10,自引:0,他引:10
研究了桑色素在pH=1~14的水溶液中的极谱行为. 于不同pH范翻内得列了四个还原波. 研究证实在pH<4条件下获得的P_1波为表面催化氢波. 其余三个波为不同形态桑色素的单电子吸附还原波, 并伴有随后化学反应过程. 测得在单分子层饱和吸附条件下, 每一个桑色素分子所占汞电极面积为1.36 nm. 相似文献
20.
A sensitive and selective method for the simultaneous determination of copper, zinc and lead is presented. The method is based on the adsorptive accumulation of 2′,3,4′,5,7-pentahydroxyflavone (Morin) complexes of these elements onto a hanging mercury drop electrode, followed by reduction of adsorbed species by voltammetric scan using differential pulse modulation. Optimal analytical conditions were found to be Morin concentration of 2.0 μM, pH of 4.0, and an adsorption potential at −500 mV versus Ag/AgCl. With an accumulation time of 60 s, the peak currents are proportional to the concentration of copper, lead and zinc over the 1 to 60, 0.3-80 and 1-70 ng ml−1 range with detection limits of 0.06, 0.08 and 0.06 ng ml−1, respectively. The procedure was applied to the simultaneous determination of copper, lead and zinc in some real and synthetic artificial real samples with satisfactory results. 相似文献