全文获取类型
收费全文 | 140篇 |
免费 | 9篇 |
国内免费 | 5篇 |
专业分类
化学 | 78篇 |
晶体学 | 2篇 |
力学 | 5篇 |
数学 | 15篇 |
物理学 | 54篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 9篇 |
2016年 | 13篇 |
2015年 | 3篇 |
2014年 | 9篇 |
2013年 | 12篇 |
2012年 | 8篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 3篇 |
2007年 | 5篇 |
2006年 | 1篇 |
2003年 | 3篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 1篇 |
排序方式: 共有154条查询结果,搜索用时 15 毫秒
121.
Mir-Michael Mousavi Mahboob Nemati Ali Akbar Alizadeh Nabili Mansour mahmoudpour Seyedrafie Arefhosseini 《Journal of the Iranian Chemical Society》2016,13(12):2211-2218
A dispersive liquid–liquid microextraction (DLLME) method followed by gas chromatography/mass spectrometry (GC/MS) was applied for the trace determination of organochlorine pesticides in honey samples. The type and volume of organic extraction and disperser solvents, pH, effect of added salt content and centrifuging time and speed were optimized to find the appropriate extraction conditions. In DLLME, 30 µL of 1,2-dibromomethane (serving as extractant) and 1.5 mL of acetonitrile (serving as disperser) were applied. The limit of detection (3 s) and limit of quantification (10 s) for all the analytes of interest (organochlorine pesticides) varied from 0.004 to 0.07 and from 0.02 to 0.3 ng g?1, respectively. The extraction recovery ranged from 91 to 100 %, and the enrichment factors ranged from 171 to 199. The relative standard deviation was <6 % for intraday (n = 6) and <8 % interday (n = 4) measurements. The proposed DLLME–GC/MS method was confirmed to be fast, simple to perform, friendly to environment and suitable for analysis of organochlorine pesticide residues at trace levels in honey samples. 相似文献
122.
Mohammad A. Bigdeli Hamideh Dostmohammadi Firouzeh Nemati Gholam Hossein Mahdavinia 《Journal of heterocyclic chemistry》2008,45(4):1203-1205
A Direct one step synthesis of various benzimidazoles from 3,4‐diaminotoluene and benzaldehydes is described using TCCA as the oxidant. The salient features of this method include simple procedure, mild condition, no waste products, easy separation, low reaction times and generality. 相似文献
123.
Mahboob Nemati Nail Altunay Mustafa Tuzen Mir Ali Farajzadeh Mohammad Reza Afshar Mogaddam 《Journal of separation science》2022,45(14):2652-2662
An organic polymer was re-precipitated in solution to use as an adsorbent in dispersive solid-phase extraction of some pesticides from honey samples prior to their determination by high-performance liquid chromatography-tandem mass spectrometry. In this approach, different deep eutectic solvents were prepared using lysine and their ability in elution of the analytes from the adsorbent surface was tested. A diluted honey solution was transferred into a glass test tube and then a solution of polystyrene dissolved in dimethylformamide was injected into the solution. By doing this, polystyrene is re-precipitated in the solution and dispersed in whole parts of it as many tiny particles. Then the mixture was centrifuged and the adsorbed analytes on the particles were eluted using a proper hydrophilic deep eutectic solvent. The central composite design approach was used for the optimization of effective parameters. The limits of detection and quantification were in the ranges of 0.06–0.20 and 0.22–0.69 ng/g, respectively. The calibration curves obtained by matrix-matched standard solutions were linear in the range of 0.69–500 ng/g with a coefficient of determinations ≥0.9962. The method provided high extraction recoveries (70–99%) and enrichment factors (140–198), and an acceptable precision (relative standard deviations ≤7.1%). 相似文献
124.
Muhammad Mudasser Khan Ali Nemati Zia Ur Rahman Umair Hussain Shah Hassnain Asgar 《固体与材料科学评论》2018,43(3):233-268
Bulk metallic glasses (BMGs), that display extraordinary properties of high strength, corrosion resistance, polymer-like formability, and excellent magnetic properties, are emerging as modern quintessential engineering materials. BMGs have garnered significant research enthusiasm owing to their tremendous technological and scientific standing. In this article, the recent advancements in the field of BMGs and their applications are put in a nutshell. Novel state-of-the-art production routes and nano/microimprinting strategies with salient features capable of circumventing the processing related complexities as well as accelerating modern developments, are briefly summarized. Heterogeneous BMG composite systems that lead to incredible combination of otherwise conflicting properties are highlighted. Biocorrosion studies and recent developments in the field of magnetic BMGs are presented owing to their significance for prospective biomedical and magnetic applications, respectively. In the last section, the current status of BMGs applications in the field of catalysis, biomedical materials, structural materials, functional materials, microelectromechanical systems (MEMS), and micro/macro devices are summed up. 相似文献
125.
For a locally compact group G, we present some characterizations for f{phi}-contractibility of the Lebesgue–Fourier algebra LA(G){mathcal{L}A(G)} endowed with convolution or pointwise product. 相似文献
126.
Nemati Chelavi Azadeh Zare-Shahabadi Vahid Sayyahi Soheil Anaraki-Ardakani Hossein 《Research on Chemical Intermediates》2020,46(1):445-458
Research on Chemical Intermediates - In this study, the transfer hydrogenation reduction of acetophenone using supported nickel on MOF as catalyst was investigated. BBD and RSM were employed to... 相似文献
127.
Mohammadreza Ghandforoush-Sattari Siminozar Mashayekhi Mahboub Nemati Philipp A. Routledge 《Chromatographia》2009,69(11-12):1427-1430
Taurine is an amino acid which is not incorporated into proteins but found in the cytosol of many mammalian cells, in high concentrations (2–30 mM). Increase in plasma taurine concentration has already been reported after surgical trauma, X-radiation, muscle necrosis, carbon tetrachloride-induced liver damage, and paracetamol overdose. Plasma taurine concentration was measured using LC with fluorescence detection following derivatization by o-phtalaldehyde plus 3-mercapto-propionic acid and α-aminobutyric acid as internal standard. Under these conditions the retention time of taurine was 10 min. This method was sensitive enough, to quantify 150 pg mL?1 and detect 50 pg mL?1 of taurine ranging normally between 65 and 179 mmol L?1 (8–22 μg mL?1). The validated method allowed simple determination of human plasma taurine in pharmacokinetic and biomarker studies. 相似文献
128.
Effects of polymer network on electrically induced reflection band broadening of cholesteric liquid crystals 下载免费PDF全文
Meina Yu Ling Wang Hossein Nemati Huai Yang Timothy Bunning Deng‐Ke Yang 《Journal of Polymer Science.Polymer Physics》2017,55(11):835-846
The reflection band of polymer stabilized cholesteric liquid crystals with negative dielectric anisotropy can be broadened by DC electric fields, which was ascribed to the pitch gradient caused by the motion of the structural chirality, that is, the polymer network. They systematically varied the mixture components, such as the photo‐initiator concentration, the monomer functionality, and the chiral dopant, to explore their influences on the reflection band broadening behavior. They learned how to control the polymer network morphology and ion density, which in turn determined the reflection bandwidth. By optimizing the mixture, they have greatly enhanced the broadening effect and achieved large bandwidth at low voltages. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 835–846 相似文献
129.
Elhampour Ali Nemati Firouzeh Nahzomi Hossein Taherpour Mohagheghi Vahid 《Research on Chemical Intermediates》2017,43(11):6737-6761
Research on Chemical Intermediates - A novel magnetic catalyst-immobilized nano-palladium was efficiently prepared via a (2 + 3) cycloaddition pathway and characterized with... 相似文献
130.