全文获取类型
收费全文 | 197篇 |
免费 | 19篇 |
国内免费 | 7篇 |
专业分类
化学 | 171篇 |
晶体学 | 4篇 |
力学 | 3篇 |
数学 | 3篇 |
物理学 | 42篇 |
出版年
2022年 | 7篇 |
2021年 | 16篇 |
2020年 | 8篇 |
2019年 | 13篇 |
2018年 | 10篇 |
2017年 | 12篇 |
2016年 | 23篇 |
2015年 | 23篇 |
2014年 | 18篇 |
2013年 | 20篇 |
2012年 | 23篇 |
2011年 | 16篇 |
2010年 | 3篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1997年 | 1篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 15 毫秒
81.
Li Li Zhao Yin Jin Yang Linghu Wensheng Chen Chaogui Asiri Abdullah M. Marwani Hadi M. Sheng Guodong 《Journal of Radioanalytical and Nuclear Chemistry》2019,321(3):1035-1044
An ammonium/hydroxyl-enriched p-BN microrods were synthesized and the adsorption behavior of uranyl on p-BN was systematically studied. The adsorption kinetic and isotherm studies revealed the adsorption behavior is independent on electrostatic attraction or chemisorption. The results demonstrate uranyl hydrolyzed precipitated crystals are formed on the surface of p-BN at an optimized pH of 2.86 and the maximum adsorption capacity can reach 413 mg g?1 at T?=?303 K. A hypothetical adsorption mechanism with a combination of surface adsorption and induced precipitation crystallization was proposed.
相似文献82.
Mixed micellization study of ibuprofen (sodium salt) and cationic surfactant (conventional as well as gemini) 下载免费PDF全文
Dileep Kumar Malik Abdul Rub Naved Azum Abdullah M. Asiri 《Journal of Physical Organic Chemistry》2018,31(1)
Herein, we have studied the interaction between cationic surfactant (conventional [myristyltrimethylammonium bromide, MTAB] as well as gemini surfactant 1, 4‐butanediyl‐α, ω‐bis(dimethyltetradecylammonium bromide) (14‐4‐14)) and anti‐inflammatory sodium salt of ibuprofen (IBU) drug in aqueous solutions by using tensiometry method at 298.15 K. The means of the interaction of drugs by added foreign materials is of paramount importance in the drug delivery. Ibuprofen is used for the relief of pain, fever, and swelling. From this study we have evaluated different parameters, for example, critical micelle concentration (cmc), micellar mole fraction of mixed micelles/mixed interface (X1m/X1σ), micellar/surface interaction parameter (βm/βσ), activity coefficients (f1m/f1σ and f2m/f2σ) of the mixed micelles/mixed interface, excess Gibbs free energy of mixed monolayer/mixed micelle formation ( / ), surface excess concentration (Γmax) etc. and discussed in detail. The micellar interaction parameter (βm) was determined from the critical micelle concentration values of the pure surfactant (MTAB/14‐4‐14) and IBU (cmc1 and cmc2) and the mixed system (cmc) using the Rubingh's model. In addition to this, various other parameters such as packing parameters of amphiphiles in the micelles (P), volume contribution of the hydrophobic chain (V0), and its effective length (lc), have also been calculated. The value of micellar mole fraction ( ) is found to be more for IBU + 14‐4‐14 mixtures as compared to IBU + MTAB mixtures at lower mole fraction and vice versa at a higher mole fraction of surfactant. The ΔGom and ΔGoads values for all studied systems were found out to be negative, ie, micellization, as well as adsorption processes, are found to be energetically favorable. 相似文献
83.
Lijun Liu Long Yu Xinfeng Chen Ji Yue Abdullah M. Asiri Hadi M. Marwani Dejian Huang Suhua Wang 《Journal of nanoparticle research》2017,19(10):344
Gold nanoparticles 1.7 and 54 nm in diameters have been synthesized and functionalized successfully with their surfaces engineered using two atropisomeric capping ligands, 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) and 1,1′-binaphthalene-2,2′-diamine (DABN), respectively. A systematic study to compare the two different gold nanoparticles is presented using multiple material characterization techniques. It was found that the two systems show different capping mechanism and hence differ in their intrinsic core and surface properties. The compound BINAP plays only surface capping agent and stabilizes the gold nanoparticles, resulting in small particle size and suppressed surface plasmon resonance absorption at 520 nm. The DABN capping ligand is different from BINAP and acts as both reducing and capping agent, causing the reduction of Au (III) to Au (0). The nucleation growth of the gold core occurs in accordance with the polymerization-passivation process by DABN, resulting in a big particle size of 20 nm. A strong surface plasmon resonance band shows a maximum peak at 564 nm, consistent with the Au core size. The simultaneous oxidative polymerization of DABN and the induced metal reduction process lead to the formation of gold nanoparticles encapsulated by a mixture of DABN oligomers or polymers. 相似文献
84.
Mohammad Y. Alshahrani Kholoud M. Alshahrani Munazzah Tasleem Arshiya Akeel Tahani M. Almeleebia Irfan Ahmad Mohammed Asiri Najla A. Alshahrani Nadiyah M. Alabdallah Mohd Saeed 《Molecules (Basel, Switzerland)》2021,26(19)
Minichromosome maintenance complex component 7 (MCM7) is involved in replicative licensing and the synthesis of DNA, and its overexpression is a fascinating biomarker for various cancer types. There is currently no effective agent that can prevent the development of cancer caused by the MCM7 protein. However, on the molecular level, inhibiting MCM7 lowers cancer-related cellular growth. With this purpose, this study screened 452 biogenic compounds extracted from the UEFS Natural Products dataset against MCM protein by using the in silico art of technique. The hit compounds UEFS99, UEFS137, and UEFS428 showed good binding with the MCM7 protein with binding energy values of −9.95, −8.92, and −8.71 kcal/mol, which was comparatively higher than that of the control compound ciprofloxacin (−6.50). The hit (UEFS99) with the minimum binding energy was picked for molecular dynamics (MD) simulation investigation, and it demonstrated stability at 30 ns. Computational prediction of physicochemical property evaluation revealed that these hits are non-toxic and have good drug-likeness features. It is suggested that hit compounds UEFS99, UEFS137, and UEFS428 pave the way for further bench work validation in novel inhibitor development against MCM7 to fight the cancers. 相似文献
85.
86.
87.
88.
89.
Sajjad Dadashi‐Silab Abdullah Mohamed Asiri Sher Bahadar Khan Khalid A. Alamry Yusuf Yagci 《Journal of polymer science. Part A, Polymer chemistry》2014,52(10):1500-1507
Photoinduced free radical polymerization of vinyl monomers by using semiconductor inorganic nanoparticles (NPs) is investigated. Zinc oxide and iron‐doped zinc oxide were used as photosensitive compounds to initiate the polymerization of acrylamide as a water‐soluble monomer in aqueous environment and methyl methacrylate as an oil‐soluble monomer in organic media under UV‐light irradiation. The method uses photochemically generated electrons and holes from the NPs to form initiating hydroxyl radicals in aqueous media, while tertiary amines and iodonium salt served as coinitiator in organic media. The initiation mechanism in organic media involves hydrogen abstraction or reduction processes via charge carriers, respectively. The kinetic of the polymerization in both environments was studied by means of a photo‐differential scanning calorimetry. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1500–1507 相似文献
90.
A.A.Leslie Gunatilaka N.P.Dhammika Nanayakkara M. Uvais S. Sultanbawa 《Tetrahedron letters》1981,22(15):1425-1428
Kokzeylanol and kokzeylanonol obtained from have been shown to be 6β,27-dihydroxy-D:A-friedo-olean-3-one () and 6β,27-dihydroxy-D:A-friedo-oleana-3,21-dione (), respectively by the deoxygenatlon of their 27-acetoxy derivatives using Lithium-ethylene diamine reduction coupled with spectroscopic and irradiation methods. Kokzeylanonol represents the first tetraoxygenated D:A-friedo-oleanane isolated from a natural source. 相似文献