全文获取类型
收费全文 | 119篇 |
免费 | 4篇 |
专业分类
化学 | 67篇 |
力学 | 5篇 |
数学 | 14篇 |
物理学 | 37篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 11篇 |
2012年 | 13篇 |
2011年 | 8篇 |
2010年 | 8篇 |
2009年 | 4篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1983年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
排序方式: 共有123条查询结果,搜索用时 15 毫秒
91.
Em. Cincu I. Manea V. Manu D. Barbos O. Sima I. Gustavsson P. Vermaercke N. Vajda Zs. Molnar H. Polkowska-Motrenko 《Journal of Radioanalytical and Nuclear Chemistry》2007,274(1):199-205
Samples of high alloy Stainless Steel SS 1 were analyzed by instrumental neutron activation analysis (INAA) at 5 research
institutes in 4 European countries within the frame of an Inter-Laboratory Comparison (ILC) exercise aiming at checking if
the results were independent of the standardization methods, and if INAA was accurate enough to contribute to certification.
The mean element concentration values yielded by INAA were also compared with mean values obtained by atomic emission spectroscopy
techniques at other laboratories that took part in the International Proficiency Testing organized by KIMAB Institute of Sweden,
producer of the SS 1. The performances of the nuclear and atomic techniques were compared in terms of the z-score values calculated for 11 element concentrations evaluated by the two analytical ways. Finally, consideration is given
to the ways in which highest accuracy and precision can be ensured for certifying stainless steels as CRMs. 相似文献
92.
The static dielectric properties of liquid and solid water are investigated within linear response theory in the context of ab initio molecular dynamics. Using maximally localized Wannier functions to treat the macroscopic polarization we formulate a first-principles, parameter-free, generalization of Kirkwood's phenomenological theory. Our calculated static permittivity is in good agreement with experiment. Two effects of the hydrogen bonds, i.e., a significant increase of the average local moment and a local alignment of the molecular dipoles, contribute in almost equal measure to the unusually large dielectric constant of water. 相似文献
93.
Dr. Anssi Peuronen Anni I. Taponen Dr. Elina Kalenius Dr. Ari Lehtonen Dr. Manu Lahtinen 《Angewandte Chemie (International ed. in English)》2023,62(7):e202215689
The design of molecular containers capable of selectively binding specific guest molecules presents an interesting synthetic challenge in supramolecular chemistry. Here, we report the synthesis and structure of a coordination cage assembled from Cu3I4− clusters and tripodal cationic N-donor ligands. Owing to the localized permanent charges in the ligand core the cage binds iodide anions in specific regions within the cage through ionic interactions. This allows the selective binding of bromomethanes as secondary guest species within the cage promoted by halogen bonding, which was confirmed by single-crystal X-ray diffraction. 相似文献
94.
We report recent efforts in the design and construction of water-walking machines inspired by insects and spiders. The fundamental
physical constraints on the size, proportion and dynamics of natural water-walkers are enumerated and used as design criteria
for analogous mechanical devices. We report devices capable of rowing along the surface, leaping off the surface and climbing
menisci by deforming the free surface. The most critical design constraint is that the devices be lightweight and non-wetting.
Microscale manufacturing techniques and new man-made materials such as hydrophobic coatings and thermally actuated wires are
implemented. Using high-speed cinematography and flow visualization, we compare the functionality and dynamics of our devices
with those of their natural counterparts.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
95.
Manu Pratap Singh Kishori Radhey Sandeep Kumar 《International Journal of Theoretical Physics》2017,56(8):2521-2534
In the present paper, simultaneous classification of Orange and Apple has been carried out using both Grover’s iterative algorithm (Grover 1996) and Ventura’s model (Ventura and Martinez, Inf. Sci. 124, 273–296, 2000) taking different superposition of two- pattern start state containing Orange and Apple both, one- pattern start state containing Apple as search state and another one- pattern start state containing Orange as search state. It has been shown that the exclusion superposition is the most suitable two- pattern search state for simultaneous classification of pattern associated with Apples and Oranges and the superposition of phase-invariance are the best choice as the respective search state based on one –pattern start-states in both Grover’s and Ventura’s methods of classifications of patterns. 相似文献
96.
Pottathil Shinu Manu Sharma Girdhari Lal Gupta Somdutt Mujwar Mahmoud Kandeel Manish Kumar Anroop B. Nair Manoj Goyal Purna Singh Mahesh Attimarad Katharigatta N. Venugopala Sreeharsha Nagaraja Mallikarjun Telsang Bandar E. Aldhubiab Mohamed A. Morsy 《Molecules (Basel, Switzerland)》2022,27(20)
The 4-allyl guaiacol is a natural phenolic molecule that has been widely studied for its antioxidant capacity against reactive-oxygen-species-mediated cellular damage. Therefore, we hypothesized that concomitant use of an antioxidant and NSAID may decrease the risk of gastrointestinal toxicity and make the therapy safer. To address the gastrointestinal toxicity of conventional NSAIDs, a new S-naproxen-4-allyl guaiacol chimera (MAS-1696) was computationally developed, chemically synthesized, and tested for anti-inflammatory effectiveness and gastrointestinal safety. The inhibitory potency of MAS-1696 tested against cyclooxygenase-2 (COX2), 15-lipoxygenase-2 (15-LOX2), and lipoxygenase-5 (5-LOX) in vitro revealed a stronger inhibition of COX2. Furthermore, the MAS-1696 chimera increased the COX selectivity index by 23% as compared to the parent compound naproxen, implying higher efficacy and gastric safety. In vivo data showed that MAS-1696 was less likely to cause gastrointestinal harm than naproxen while also exerting anti-inflammatory and analgesic effects equivalent to or superior to naproxen. In conclusion, MAS-1696 is orally active, bio-labile, and crystalline, making it a medication that may be administered orally. 相似文献
97.
Papanna Roopa Kothathi Kanakapura Basavaiah Gowda Shankara Bujuvally Shivaiah Basavaraju Mahesh Puttegowda Veena Keregodu 《Journal of Analytical Chemistry》2021,76(11):1262-1270
Journal of Analytical Chemistry - Four simple, precise and sensitive visible spectrophotometric methods were developed for the determination of solifenacin succinate in pure and pharmaceutical... 相似文献
98.
Jose Manu Kumari Mahitha Karunakaran Remya Shukla Satyajit 《Journal of Sol-Gel Science and Technology》2015,75(1):38-44
Journal of Sol-Gel Science and Technology - Highly crystalline nanotubes/nanoplates of pure and Ag-doped anatase-titania (TiO2) having high aspect-ratio have been synthesized, without the... 相似文献
99.
Dr. Nonappa Johannes S. Haataja Prof. Jaakko V. I. Timonen Dr. Sami Malola Dr. Peter Engelhardt Dr. Nikolay Houbenov Dr. Manu Lahtinen Prof. Hannu Häkkinen Prof. Olli Ikkala 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(23):6573-6577
The synthesis and spontaneous, reversible supracolloidal hydrogen bond-driven self-assembly of cobalt nanoparticles (CoNPs) into hollow shell-like capsids and their directed assembly to higher order superstructures is presented. CoNPs and capsids form in one step upon mixing dicobalt octacarbonyl (Co2CO8) and p-aminobenzoic acid (pABA) in 1,2-dichlorobenzene using heating-up synthesis without additional catalysts or stabilizers. This leads to pABA capped CoNPs (core ca. 5 nm) with a narrow size distribution. They spontaneously assemble into tunable spherical capsids (d≈50–200 nm) with a few-layered shells, as driven by inter-nanoparticle hydrogen bonds thus warranting supracolloidal self-assembly. The capsids can be reversibly disassembled and reassembled by controlling the hydrogen bonds upon heating or solvent exchanges. The superparamagnetic nature of CoNPs allows magnetic-field-directed self-assembly of capsids to capsid chains due to an interplay of induced dipoles and inter-capsid hydrogen bonds. Finally, self-assembly on air–water interface furnishes lightweight colloidal framework films. 相似文献
100.