全文获取类型
收费全文 | 103篇 |
免费 | 9篇 |
出版年
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 8篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1994年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1983年 | 3篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有112条查询结果,搜索用时 234 毫秒
1.
The paper presents a computationally effective method for fault detection. A system’s responses are measured under healthy and ill conditions. These signals are used to calculate so-called signature functions that create a signal space. The current system’s response is projected into this space. The signal location in this space easily allows to determine the fault. No classifier such as a neural network, hidden Markov models, etc. is required. The advantage of this proposed method is its efficiency, as computing projections amount to calculating dot products. Therefore, this method is suitable for real-time embedded systems due to its simplicity and undemanding processing capabilities which permit the use of low-cost hardware and allow rapid implementation. The approach performs well for systems that can be considered linear and stationary. The communication presents an application, whereby an industrial process of moulding is supervised. The machine is composed of forms (dies) whose alignment must be precisely set and maintained during the work. Typically, the process is stopped periodically to manually control the alignment. The applied algorithm allows on-line monitoring of the device by analysing the acceleration signal from a sensor mounted on a die. This enables to detect failures at an early stage thus prolonging the machine’s life. 相似文献
2.
3.
Barbara Pietrzak Anna Bednarska Magdalena Markowska Maciej Rojek Ewa Szymanska Miroslaw Slusarczyk 《Hydrobiologia》2013,715(1):125-134
The combined effect of external environment and energy allocation strategy of the organism on longevity can be exceptional. In a cold oligotrophic fishless habitat, individual Daphnia can live for over a year, several times the usual Daphnia lifespan. This extreme lifespan is in part a consequence of the overwintering strategy which includes storing resources and delaying reproduction until another spring. Yet, contrasting strategies may be applied by Daphnia, resulting in over twofold differences in lifespan within a single habitat. We identify physiological mechanisms mediating such differences in longevity in closely related Daphnia of two lineages coexisting within a high altitude lake, testing the predictions that long-lived animals stay in colder waters and have lower metabolic rates, irrespective of temperature. Vertical distribution of the animals was assessed during three summer stratification seasons, and metabolic activity was measured as oxygen consumption and RNA:DNA ratio. The results not only support our predictions but also reveal that habitat choice is dependent on reproductive status rather than genotype. The young individuals of the overwintering lineage may delay reproduction in part by staying in colder waters than the reproducing adults, which together with low intrinsic metabolic rates may underlie the longevity of Daphnia of this lineage. 相似文献
4.
5.
Magdalena Paczkowska Miko?aj Mizera Hanna Piotrowska Daria Szymanowska-Powa?owska Kornelia Lewandowska Joanna Goscianska Robert Pietrzak Waldemar Bednarski Zbigniew Majka Judyta Cielecka-Piontek 《PloS one》2015,10(3)
This study aimed to obtain and characterize an RU-β-CD complex in the context of investigating the possibility of changes in the solubility, stability, antioxidative and microbiological activity as well as permeability of complexated rutin as against its free form. The formation of the RU-β-CD complex via a co-grinding technique was confirmed by using DSC, SEM, FT-IR and Raman spectroscopy, and its geometry was assessed through molecular modeling. It was found that the stability and solubility of the so-obtained complex were greater compared to the free form; however, a slight decrease was observed inits antibacterial potency. An examination of changes in the EPR spectra of thecomplex excluded any reducing effect of complexation on the antioxidative activity of rutin. Considering the prospect of preformulation studies involving RU-β-CD complexes, of significance is also the observed possibility of prolongedly releasing rutin from the complex at a constant level over along period of 20 h, and the fact that twice as much complexated rutin was able topermeate compared to its free form. 相似文献
6.
7.
8.
Specificity of Formation of Complexes Between Coat Protein and Bacteriophage f2 RNA 总被引:2,自引:2,他引:0 下载免费PDF全文
The specificity of formation of phage f2 RNA-protein complexes was studied. Complex I contains up to 8 mol of coat protein per 1 mol of RNA. Its formation proceeds equally well in medium (i) without magnesium ions, (ii) containing magnesium ions, (iii) containing 4 mM EDTA, and (iv) at temperatures from 0 to 45 C. Complex II contains up to 200 mol of coat protein per 1 mol of RNA. Its formation is inhibited by the presence of magnesium ions in medium. Formaldehyde- or methoxyamine-treated f2 RNA in which only exposed bases were modified showed a normal pattern of complex II formation, whereas formation of complex I was inhibited or abolished. We conclude that complex I formation involves the interaction between coat protein and specific region of exposed bases in RNA. A possible site of attachment of coat protein is discussed. 相似文献
9.
10.
Pietrzak A Zalewska A Chodorowska G Nockowski P Michalak-Stoma A Osemlak P Krasowska D 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》2008,46(1):11-21
Psoriasis is a common skin disease involving 1-4% of human population worldwide, of strong genetic background. The following cytokines are directly involved in psoriasis: TNF, IL-1, IL-2, IL-6, IL-7, IL-8, IL-15, IL-18, IL-19, IL-20, IL-23 whereas IL-4, IL-10, IL-12 as well as IL-11, IL-17 and IFN-gamma are rather indirectly engaged. This work is a review of some genetic factors and structure of selected cytokines and receptors and their genes location. 相似文献