全文获取类型
收费全文 | 327篇 |
免费 | 13篇 |
国内免费 | 2篇 |
专业分类
化学 | 221篇 |
晶体学 | 1篇 |
力学 | 8篇 |
数学 | 56篇 |
物理学 | 56篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 23篇 |
2021年 | 19篇 |
2020年 | 17篇 |
2019年 | 22篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 14篇 |
2014年 | 14篇 |
2013年 | 33篇 |
2012年 | 18篇 |
2011年 | 20篇 |
2010年 | 15篇 |
2009年 | 13篇 |
2008年 | 16篇 |
2007年 | 11篇 |
2006年 | 10篇 |
2005年 | 8篇 |
2004年 | 9篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1980年 | 4篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有342条查询结果,搜索用时 0 毫秒
101.
Cemil Aydoğan Fatma Yılmaz Duygu Çimen Lokman Uzun Adil Denizli 《Electrophoresis》2013,34(13):1908-1914
A new type of polymethacrylate‐based monolithic column with chiral stationary phase was prepared for the enantioseparation of aromatic amino acids, namely d ,l ‐phenylalanine, d ,l ‐tyrosine, and d ,l ‐tryptophan by CEC. The monolithic column was prepared by in situ polymerization of butyl methacrylate (BMA), N‐methacryloyl‐l ‐histidine methyl ester (MAH), and ethylene dimethacrylate (EDMA) in the presence of porogens. The porogen mixture included DMF and phosphate buffer. MAH was used as a chiral selector. FTIR spectrum of the polymethacrylate‐based monolith showed that MAH was incorporated into the polymeric structure via in situ polymerization. Some experimental parameters including pH, concentration of the mobile phase, and MAH concentration with regard to the chiral CEC separation were investigated. Single enantiomers and enantiomer mixtures of the amino acids were separately injected into the monolithic column. It was observed that l ‐enantiomers of aromatic amino acids migrated before d ‐enantiomers. The reversal enantiomer migration order for tryptophan was observed upon changing of pH. Using the chiral monolithic column (100 μm id and 375 μm od), the best chiral separation was performed in 35:65% ACN/phosphate buffer (pH 8.0, 10 mM) with an applied voltage of 12 kV in CEC. SEM images showed that the chiral monolithic column has a continuous polymeric skeleton and large through‐pore structure. 相似文献
102.
Rajkumar Joshi Guruaribam Shashikumar Sharma Vikrant Kumar Athar Adil Hashmi Satyendra Kumar R. Achila M. Ejaz Hussain 《应用有机金属化学》2006,20(11):740-746
A heteroscorpionate ligand, potassium hydrobis(benzoato)(salicylaldehyde)borate (KL), has been synthesized. This was converted into organotin complexes R2SnL2 and R3SnL complexes by mixing and stirring with a methanolic solution/suspension of organotin chloride. The ligand and its complexes were characterized by elemental analyses and spectral studies (IR, 1H NMR, 13C NMR, ESI mass spectra and Thermo gravimetric analysis (TGA)). Antibacterial and antifungal studies of these compounds were evaluated by the disc diffusion method at variable concentration against three species of bacteria (Staphylococcus aureus, Klebsiella pneumonia and Bacillius subtillis) and two species of fungi (Asperjillius fiavus and Candida albicans). It was found that triorganotin derivatives (R3SnL) of the ligand were more effective as compared with diorganotin derivatives (R2SnL2). The organotin complexes of borates were tested for their algicidal activity on the cyanobacterial strains Aulosira fertilissma, Anabaena species, Anabaena variabilis and Nostoc muscorum and showed high to moderate toxicity towards the above species. The ligand and its complexes were also tested for its pH effect on soil in vitro for a duration of more than one month and it was found that they are able to kill pests without damaging the soil quality. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
103.
104.
The collision energy dependence of jet tomography is investigated within the GLV formalism. We estimate systematic uncertainties resulting from the interplay of energy loss fluctuations and the rapid increase of the parton transverse momentum slopes as √s decreases from 200 to 62.4 AGeV. 相似文献
105.
The molecular hyperpolarizability of some donor–acceptor oxadiazoles was investigated using ab initio methods. Ab initio optimizations
were performed at the Hartree-Fock level using different basis sets, starting with the minimal basis set, and then split valence
sets. The first hyperpolarizabilities were calculated at the Hartree-Fock level employing the corresponding basis sets using
Gaussian 98W. In general, the first hyperpolarizability is dependent on the choice of method and basis set. In order to understand
this phenomenon in the context of molecular orbital picture, we examined the molecular HOMOs and molecular LUMOs generated
via HF/6-31G level. It has also been calculated the polarizability, anisotropy of polarizability and ground state dipole moment
of all the molecules. Several of these oxadiazoles display significant second-order molecular nonlinearity, β(8.57–195.05 × 10−30 esu) and provide the basis for future design of efficient nonlinear optical materials having the oxadiazole core. 相似文献
106.
Davut Avcı Sümeyye Altürk Fatih Sönmez Ömer Tamer Adil Başoğlu Yusuf Atalay Belma Zengin Kurt Necmi Dege 《应用有机金属化学》2020,34(4):e5412
A series of mixed-ligand M(II) complexes containing 1,10-phenanthroline (phen) and 3-methylpyridine-2-carboxylic acid (3-mpaH) or 6-methylpyridine-2-carboxylic acid (6-mpaH), namely [Co(3-mpa)2(phen)]·3H2O ( 1 ), [Hg(6-mpa)2(phen)]·2H2O ( 2 ), [Mn(6-mpa)2(phen)]·2H2O ( 3 ), [Co(6-mpa)2(phen)]·H2O ( 4 ) and [Ni(6-mpa)2(phen)]·H2O ( 5 ), were synthesized for the first time. Among them, 1 was obtained as single crystals. The structural characterization for 1 was conducted using X-ray diffraction and that for 2 – 5 using mass spectrometry. The IC50 values for α-glucosidase inhibition of 1 – 5 were obtained as 0.161 to >600 μM. The spectral properties were also investigated using Fourier transform infrared and UV–visible spectra. Furthermore, to investigate the geometrical parameters, spectral and electronic properties and second- and third-order nonlinear optical parameters for 1 – 5 , density functional calculations were applied. 相似文献
107.
Adil Omar 《Green Chemistry Letters and Reviews》2019,12(1):1-8
A simple, efficient, eco-friendly and catalyst-free procedure was developed for the construction of novel coumarin-spiro[indoline-3,4'-pyran] conjugates via three-component reactions of various synthetic beta-ketoesters with isatins and malononitrile in aqueous medium. In addition to operational simplicity and absence of tedious separation procedures, being catalyst–free is the prominent advantage of this method. 相似文献
108.
A generalized bridge is a stochastic process that is conditioned on N linear functionals of its path. We consider two types of representations: orthogonal and canonical. The orthogonal representation is constructed from the entire path of the process. Thus, the future knowledge of the path is needed. In the canonical representation the filtrations of the bridge and the underlying process coincide. The canonical representation is provided for prediction-invertible Gaussian processes. All martingales are trivially prediction-invertible. A typical non-semimartingale example of a prediction-invertible Gaussian process is the fractional Brownian motion. We apply the canonical bridges to insider trading. 相似文献
109.
Adil Amin Aijaz Ahmad Dar Mohsin Ahmad Bhat Musarat Jan Nuzhat Rehman Mohammad Amin Mir 《Journal of Dispersion Science and Technology》2013,34(3):406-414
The present study deals with the interaction of sodium alkanoates viz. sodium acetate, sodium propionate, sodium butanoate, sodium hexanoate and sodium benzoate on the micellization of dodecylbenzyldimethylammonium chloride using conductometeric and flourscence quenching experiments carried out at 25°C. The analysis has been made through study of variation of critical micelle concentration (cmc), degree of counterion binding (β), aggregation number (N), and micropolarity with the concentration of these hydrophobic salts. The differentiation between the effects of hydrophobic and inorganic salts was made by comparing the above results with the influence of NaCl on cmc, β, and N. 相似文献
110.
R. Elwej N. Hannachi K. Adil F. Hlel 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):1173-1182
An orthophosphoric hybrid material was successfully prepared by a hydrothermal reaction at 110 °C. A single crystal X-ray structure, thermal behavior, IR, and NMR spectroscopy investigations are given for a new organic cation bis dihydrogenomonophosphate C7H12N2[H2PO4]2.1/2H2O. The latter has been synthesized hydrothermally using 2,4-diaminotoluene (DAT) and orthophosphoric acid. The atomic arrangement can be described as inorganic sheets alternating with inorganic-organic layers. The organic group C7H12N+ 2 is located between inorganic groups to build multiple hydrogen bonds to ensure the three-dimensional cohesion network. The thermal behavior and IR, NMR and impedance spectroscopy studies are discussed for the powder samples of this compound. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献