全文获取类型
收费全文 | 69篇 |
免费 | 0篇 |
专业分类
化学 | 21篇 |
数学 | 5篇 |
物理学 | 43篇 |
出版年
2021年 | 1篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1932年 | 2篇 |
排序方式: 共有69条查询结果,搜索用时 296 毫秒
21.
P I Ohlsson T Horie J M Vanderkooi K G Paul 《Acta chemica Scandinavica. Series B: Organic chemistry and biochemistry》1986,40(4):257-261
Fluorescent derivatives of horseradish peroxidase C were prepared by replacing protoheme by protoporphyrin or mesoporphyrin. Calculations according to F?rster on energy transfer allowed the determination of the distances of greater than 2.2 nm between tryptophan and porphyrin (heme) and greater than 2 nm between tryptophan and substrate-binding site. The modification of the single tryptophan with 2-hydroxy-5-nitrobenzyl bromide (Koshland's reagent) did not affect the enzyme's activity towards hydrogen peroxide or ascorbate. Modified and unmodified peroxidase showed the same affinity for aromatic substrates. 相似文献
22.
23.
24.
K. E. Anders Ohlsson Anders Cedergren Wolfgang Frech 《Spectrochimica Acta Part B: Atomic Spectroscopy》1992,47(14):1525-1533
Clear experimental evidence is given showing that AlH molecules are present during the spike-like Al atomic absorbance signals obtained when samples containing> 500 ng aluminium are slowly heated in a graphite atomizer. The molecules CN(g) or C2(g) were not observed, which does not, however, rule out the involvement of Al2C2(g) in the spike formation process. The AIH molecules are probably formed in the gas phase from aluminium and hydrogen. The partial pressure of the latter is estimated to be 200–600 Pa and seems to be constant during the Al spike. 相似文献
25.
Methods for short-term BOD analysis (BODst) based on ferricyanide mediator reduction have succeeded in overcoming some problems associated with the standard BOD test analysis (BOD5) such as long-term incubations (5 days), the need to dilute samples and low reproducibility. Here we present a bioassay where a Klebsiella pneumoniae environmental strain successfully reduces ferricyanide without de-aeration of the samples with linear BOD5 ranges between 30 and 500 mg L−1 or 30 and 200 mg L−1, using glucose-glutamic acid solution (GGA) or OECD standards respectively. We further propose a new assay termination solution that allows higher reproducibility and standardization of the cell-based assay, employing formaldehyde (22.7 g L−1) or other compounds in order to stop ferricyanide reduction without affecting the amperometric detection and therefore replace the centrifugation step normally used to stop microbial-driven reactions in ferricyanide-mediated bioassays. These improvements led to an accurate determination of real municipal wastewater samples. 相似文献
26.
In this article, we derive the intrinsic equations for a generalized relaxed elastic line on an oriented surface in the Galilean 3-dimensional space G3. These equations will give direct and more geometric approach to questions concerning about generalized relaxed elastic lines on an oriented surface in G3. 相似文献
27.
We propose a simplified version of the inverse seesaw model, in which only two pairs of the gauge-singlet neutrinos are introduced, to interpret the observed neutrino mass hierarchy and lepton flavor mixing at or below the TeV scale. This “minimal” inverse seesaw scenario (MISS) is technically natural and experimentally testable. In particular, we show that the effective parameters describing the non-unitary neutrino mixing matrix are strongly correlated in the MISS, and thus, their upper bounds can be constrained by current experimental data in a more restrictive way. The Jarlskog invariants of non-unitary CP violation are calculated, and the discovery potential of such new CP-violating effects in the near detector of a neutrino factory is discussed. 相似文献
28.
Lenneke WA van Hooijdonk Muhammad Ichwan Thomas F Dijkmans Theo G Schouten Marijke WA de Backer Roger AH Adan Fons J Verbeek Erno Vreugdenhil Carlos P Fitzsimons 《BMC neuroscience》2009,10(1):2-19
Background
In the adult hippocampus, the granule cell layer of the dentate gyrus is a heterogeneous structure formed by neurons of different ages, morphologies and electrophysiological properties. Retroviral vectors have been extensively used to transduce cells of the granule cell layer and study their inherent properties in an intact brain environment. In addition, lentivirus-based vectors have been used to deliver transgenes to replicative and non-replicative cells as well, such as post mitotic neurons of the CNS. However, only few studies have been dedicated to address the applicability of these widespread used vectors to hippocampal cells in vivo. Therefore, the aim of this study was to extensively characterize the cell types that are effectively transduced in vivo by VSVg-pseudotyped lentivirus-based vectors in the hippocampus dentate gyrus. 相似文献29.
30.
Eva Millqvist Mats Bende Moa Brynnel Inger Johansson Sofi Kappel Ann-Christine Ohlsson 《Journal of voice》2008,22(4):512-515
Voice problems are seldom reported in pollen allergy, although the allergic reaction involves the entire airways. The objective of this study was to investigate voice dysfunction during the pollen season in patients with allergic rhinitis. Thirty patients with verified birch pollen allergy and 30 controls were investigated twice, during the pollen season and outside the pollen season. Both times they scored respiratory and voice symptoms, the latter with the validated questionnaire Voice Handicap Index (VHI), and performed standardized voice recordings. These recordings were analyzed in a controlled manner by a professional voice therapist. During the allergy season, patients reported more respiratory and voice symptoms compared with controls. Those with blinded scored voice dysfunction scored their voice quality during springtime as 31 mm (95% confidence interval [CI] 20-42 mm), compared with 13 mm (95% CI 6-21 mm for participants without voice dysfunction (P<0.01). Furthermore, the group with experienced voice dysfunction scored significantly higher on the VHI in the functional and physical domains and in the total VHI score. Although voice problems during the pollen season are rarely discussed, in allergic rhinitis the larynx may also be involved. These findings support that some patients experience voice change, an experience which can be objectively confirmed. 相似文献