全文获取类型
收费全文 | 182篇 |
免费 | 5篇 |
国内免费 | 1篇 |
专业分类
化学 | 107篇 |
晶体学 | 1篇 |
力学 | 4篇 |
数学 | 20篇 |
物理学 | 56篇 |
出版年
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 2篇 |
2019年 | 8篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 9篇 |
2012年 | 10篇 |
2011年 | 13篇 |
2010年 | 10篇 |
2009年 | 11篇 |
2008年 | 16篇 |
2007年 | 9篇 |
2006年 | 12篇 |
2005年 | 5篇 |
2004年 | 7篇 |
2003年 | 1篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1989年 | 1篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1983年 | 1篇 |
排序方式: 共有188条查询结果,搜索用时 15 毫秒
181.
This paper is concerned with two related types of directed polymers in a random medium. The first one is a d-dimensional Brownian motion living in a random environment which is white-noise in time and homogeneous in space. The second
is a continuous-time discrete-space Markov process on ℤ
d
, in a random environment with similar properties as in continuous space, albeit defined only on . The case of a space-time white noise environment can be achieved in this second setting. By means of some Gaussian tools,
we estimate the free energy of these models at low temperature, and give some further information on the strong disorder regime
of the objects under consideration.
Frederi Viens’ research partially supported by NSF grants no.: DMS 0204999 and DMS 0606615. 相似文献
182.
P Kodali A Jurkevica J Landero C Kuhlmann J Caruso O Adeoye 《Journal of separation science》2012,35(17):2153-2161
Stroke is the most common cause of morbidity and death in the Western world, following ischemic heart disease and cancer. Stroke can be of two types, ischemic or hemorrhagic, with ischemic stroke accounting for approximately 85% of the total number of strokes. Well-recognized environmental risk factors for stroke include hypertension, smoking, diabetes mellitus, atrial fibrillation, and atherosclerosis. Computed tomography (CT) scanning is used to diagnose hemorrhagic stroke but is relatively ineffective and may remain normal in patients with mild ischemic strokes. Magnetic Resonance Imaging (MRI) is more sensitive in detecting ischemia than CT, especially in the diagnosis of mild stroke but it is still not 100% sensitive or precise. A simple and low-cost, rapid blood test to confirm a clinical and imaging diagnosis of ischemic stroke would be extremely useful. Based on this, the central idea of this paper is to develop a method that would be applicable to a statistically viable sample set to provide candidate biomarkers for distinguishing stroke types. In search of these candidate biomarkers, different analytical separation techniques have been used to screen for major differences in the proteomes of patients plasma samples with proteomics for identification. 相似文献
183.
Marcelli T van Maarseveen JH Hiemstra H 《Angewandte Chemie (International ed. in English)》2006,45(45):7496-7504
In the steadily expanding field of organocatalysis, cinchona alkaloids play a prominent role. Until the late 1990s, bifunctional catalysts based on this scaffold relied exclusively on the C9-hydroxy group as the hydrogen-bond donor. Recently, new cinchona catalysts have been developed that feature a phenolic OH group in the C6' position-a structural feature that allows a diverse set of reactions to be catalyzed in a highly stereoselective fashion. This Minireview describes the scope and modes of action of this new class of asymmetric bifunctional organocatalysts. 相似文献
184.
185.
We consider the Dirichlet problem for a class of anisotropic degenerate elliptic equations. 相似文献
186.
F. Ceyda Dudak İsmail H. Boyacı Agnese Jurkevica Mahmud Hossain Zoraida Aquilar H. Brian Halsall Carl J. Seliskar William R. Heineman 《Analytical and bioanalytical chemistry》2009,393(3):949-956
A rapid and convenient assay system was developed to detect viable Escherichia coli in water. The target bacteria were recovered from solution by immunomagnetic separation and incubated in tryptic soy broth
with isopropyl-β-d-thiogalactopyranoside, which induces formation of β-galactosidase in viable bacteria. Lysozyme was used to lyse E. coli cells and release the β-galactosidase. β-Galactosidase converted 4-methylumbelliferyl-β-d-galactoside to 4-methylumbelliferone (4-MU), which was measured by fluorescence spectrophotometry using excitation and emission
wavelengths of 355 and 460 nm, respectively. Calibration graphs of 4-MU fluorescence intensity versus E. coli concentration showed a detection range between 8 × 104 and 1.6 × 107 cfu mL−1, with a total analysis time of less than 3 h. The advantage of this method is that it detects viable cells because it is
based on the activity of the enzyme intrinsic to live E. coli. 相似文献
187.
Paolo Inaudi Elio Mondino Ornella Abollino Mery Malandrino Monica Argenziano Laura Favilli Roberto Boschini Agnese Giacomino 《Molecules (Basel, Switzerland)》2022,27(10)
A measurement and speciation procedure for the determination of total mercury (HgTOT), inorganic mercury (HgIN), and methylmercury (CH3Hg) was developed and the applicability for on-site determination was demonstrated. A simple, portable sample pretreatment procedure was optimized to extract the analytes. Home-made columns, packed with a new sorbent material called CYXAD (CYPHOS 101 modified Amberlite XAD), were used to separate the two forms of the analyte. HgTOT and CH3Hg were determined by anodic stripping voltammetry (ASV), using a solid gold electrode (SGE). Two certified reference materials (BCR-463 Tuna Fish and Tuna Fish ERM-CE 464) and eight fresh fishes were analyzed. Then, the results that were obtained following the optimized portable procedure were compared with the concentrations obtained, using a direct mercury analyzer (DMA). This quantification, using the two techniques, demonstrated the good performance of the proposed method. 相似文献
188.
Agnese Giacomino Paolo Inaudi Gessica Silletta Aleandro Diana Stefano Bertinetti Elisa Gaggero Mery Malandrino Federico Stilo Ornella Abollino 《Molecules (Basel, Switzerland)》2023,28(1)
The determination of the authenticity of extra virgin olive oils (EVOOs) has become more interesting in recent years. Italy is the first country in Europe in terms of number of Protected Designation of Origin (PDO) oils, which connects consumers to a feeling of tradition and thus to higher quality standards. This work focused on the consideration of the inorganic content as a possible marker of EVOOs. Ten vegetable oils (VOs), eight Italian EVOOs and seven not Italian EVOOs were analyzed. After pretreatment by acid mineralization, Al, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, Sb, Se and Zn were determined by ICP-OES. The electrochemical properties of a selected group of EVOOs and other vegetal oils of different botanical origin were investigated by voltammetry. Carbon paste electrodes (CPEs) were prepared. The features observed in the voltammograms reflect the reactions of electroactive compounds, which are present in the oils. A chemometric treatment of the results was performed to assess the possibility to distinguish (i) the region of provenience considering the inorganic profile; and (ii) the plant species from which each oil was obtained on the basis of the current profile registered during voltammetric analysis. Inorganic composition seems to be a useful marker for the assessment of the geographical origin of an EVOO. The EVOO-CPEs voltammetry seems to have a good ability to distinguish the plant species of origin. This method could be useful to monitor the conservation status of the oils, as the redox profile is linked to the oxidative degradation state. 相似文献