全文获取类型
收费全文 | 118篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
化学 | 43篇 |
力学 | 5篇 |
数学 | 34篇 |
物理学 | 39篇 |
出版年
2019年 | 1篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2013年 | 7篇 |
2012年 | 5篇 |
2011年 | 8篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 5篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1956年 | 1篇 |
1940年 | 2篇 |
排序方式: 共有121条查询结果,搜索用时 15 毫秒
101.
Bahman N Shokouhi Bernadette ZY Wong Samir Siddiqui A Robert Lieberman Gregor Campbell Koujiro Tohyama Patrick N Anderson 《BMC neuroscience》2010,11(1):13
Background
Microglia/macrophages and lymphocytes (T-cells) accumulate around motor and primary sensory neurons that are regenerating axons but there is little or no microglial activation or T-cell accumulation around axotomised intrinsic CNS neurons, which do not normally regenerate axons. We aimed to establish whether there was an inflammatory response around the perikarya of CNS neurons that were induced to regenerate axons through a peripheral nerve graft. 相似文献102.
Volatile organic compounds generated by cultures of bacteria and viruses associated with respiratory infections
下载免费PDF全文
![点击此处可从《Biomedical chromatography : BMC》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Amir Abd El Qader David Lieberman Yonat Shemer Avni Natali Svobodin Tsilia Lazarovitch Orli Sagi Yehuda Zeiri 《Biomedical chromatography : BMC》2015,29(12):1783-1790
Respiratory infections (RI) can be viral or bacterial in origin. In either case, the invasion of the pathogen results in production and release of various volatile organic compounds (VOCs). The present study examines the VOCs released from cultures of five viruses (influenza A, influenza B, adenovirus, respiratory syncitial virus and parainfluenza 1 virus), three bacteria (Moraxella catarrhalis, Haemophilus influenzae and Legionella pneumophila) and Mycoplasma pneumoniae isolated colonies. Our results demonstrate the involvement of inflammation‐induced VOCs. Two significant VOCs were identified as associated with infectious bacterial activity, heptane and methylcyclohexane. These two VOCs have been linked in previous studies to oxidative stress effects. In order to distinguish between bacterial and viral positive cultures, we performed principal component analysis including peak identity (retention time) and VOC concentration (i.e. area under the peak) revealing 1‐hexanol and 1‐heptadecene to be good predictors. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
103.
Michael Lieberman Jiří Rosický Sebastien Vasey 《Journal of Pure and Applied Algebra》2019,223(10):4560-4582
Working in the context of μ-abstract elementary classes (μ-AECs)—or, equivalently, accessible categories with all morphisms monomorphisms—we examine the two natural notions of size that occur, namely cardinality of underlying sets and internal size. The latter, purely category-theoretic, notion generalizes e.g. density character in complete metric spaces and cardinality of orthogonal bases in Hilbert spaces. We consider the relationship between these notions under mild set-theoretic hypotheses, including weakenings of the singular cardinal hypothesis. We also establish preliminary results on the existence and categoricity spectra of μ-AECs, including specific examples showing dramatic failures of the eventual categoricity conjecture (with categoricity defined using cardinality) in μ-AECs. 相似文献
104.
105.
Cheng-yi Chen David R. Lieberman Leslie J. Street Alex R. Guiblin Robert D. Larsen Thomas R. Verhoeven 《合成通讯》2013,43(10):1977-1984
A palladium-catalyzed coupling of iodoaniline 2 with bis-TES propargyl alcohol 3 gives indole-3-methanol 4b in 72% yield. Displacement of the hydroxy group of 4b by sodium cyanide followed by hydrolysis of the cyano group and desilylation provides the indole acetic acid metabolite, L-749,335 (1), of the 5-HT1D receptor agonist MK-0462. 相似文献
106.
107.
108.
Relaxation oscillations due to plasma instabilities at frequencies
ranging from a few Hz to tens of kHz have been observed in various
types of plasma processing discharges. Relaxation oscillations have
been observed in electropositive capacitive discharges between a
powered anode and a metallic chamber whose periphery is grounded
through a slot with dielectric spacers. The oscillations of
time-varying optical emission from the main discharge chamber show,
for example, a high-frequency (\sim 40~kHz) relaxation
oscillation at 13.33Pa, with an absorbed power being nearly the
peripheral breakdown power, and a low-frequency ( \sim 3 Hz)
oscillation, with an even higher absorbed power. The high-frequency
oscillation is found to ignite plasma in the slot, but usually not in
the peripheral chamber. The kilohertz oscillations are modelled using
an electromagnetic model of the slot impedance, coupled to a circuit
analysis of the system including the matching network. The model
results are in general agreement with the experimental observations,
and indicate a variety of behaviours dependent on the matching
conditions. In low-pressure inductive discharges, oscillations appear
in the transition between low-density capacitively driven and
high-density inductively driven discharges when attaching gases such
as SF6 and Ar/SF6 mixtures are used. Oscillations of
charged particles, plasma potential, and light, at frequencies
ranging from a few Hz to tens of kHz, are seen for gas pressures
between 0.133 Pa and 13.33 Pa and discharge powers in a range of
75--1200 W. The region of instability increases as the plasma becomes
more electronegative, and the frequency of plasma oscillation
increases as the power, pressure, and gas flow rate increase. A
volume-averaged (global) model of the kilohertz instability has been
developed; the results obtained from the model agree well with the
experimental observations. 相似文献
109.
B.V. Chirikov M.A. Lieberman D.L. Shepelyansky F.M. Vivaldi 《Physica D: Nonlinear Phenomena》1985,14(3):289-304
Modulational diffusion, a weak instability that frequently occurs in many-dimensional, nonlinear Hamiltonian systems, is studied both analytically and numerically. Modulational diffusion arises when an oscillation in one of the degrees of freedom is phase modulated at a slow driving frequency, producing a “modulational layer” of overlapping resonances in phase spaces. Because the motion within this layer is chaotic, any coupling to the oscillation of another degree of freedom produces a long-time diffusion of its associated action along the layer. The diffusion rate for this process is evaluated analytically, and is compared with numerical calculations for a model, two-degree-of-freedom, nonautonomous Hamiltonian. The diffusion coefficient is found to vary in a series of descending steps as the frequency difference between the two oscillators is increased. Good agreement between analytical and numerical results has been obtained over many orders of magnitude in the diffusion coefficient. 相似文献
110.