全文获取类型
收费全文 | 118篇 |
免费 | 4篇 |
专业分类
化学 | 54篇 |
晶体学 | 8篇 |
力学 | 17篇 |
数学 | 23篇 |
物理学 | 20篇 |
出版年
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 1篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 5篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有122条查询结果,搜索用时 0 毫秒
41.
In this study, two novel 4,4′-difluoro-4-bora-3a,4a-diaza-s-indacenes (BODIPY)-based metal ion sensors were synthesised using ‘click’ chemistry. The coordination modes and binding constants of the complexes formed with a range of metal ions were calculated. Results indicate that both BODIPY molecules can potentially serve as fluorescent sensors for the studied metal cations. The results also show that the BODIPY-based sensors have more selectivity for Zn (II) ions in the presence of other metal ions. 相似文献
42.
We observed the surface morphology and adhesive interaction of adsorbents on rubber substrates by atomic force microscopy (AFM). The detachment of adsorbents from rubber substrates is an important issue for various machines like home appliances and laundry machine. Since a clean surface of the functioning parts is required, a frequent cleaning process must be developed. In particular, dust and lint have a tendency to bind to the rubber surface of a laundry machine. Several practical methods have been attempted to remove these particles from the surface. Pure water, detergent, sodium hypochlorite (65 °C), and cold water (18 °C) are treated onto artificial dust and lint mixtures on rubber with water fluid by rapid rpm. The dust‐and‐lint adsorbents are investigated by AFM after the treatment, and topographic images and force–distance (F–D) curves were generated for the samples. The roughness, measured as the root mean square, is a key factor to judge the cleaning quality. From the F–D curves, we are able to obtain adhesive energy in addition to adhesive force which will yield qualitative measures of the interactions between the remaining adsorbents and the rubber surface. Considering the values that were measured, hot water with water fluid by rapid rpm offers the best performance when cleaning the surface. The chemical like sodium hypochlorite is good for thinning the materials, but it solidifies them, which is eventually detrimental to proper functioning. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
43.
44.
The results of phase equilibria predictions for the Na,K∥SO4,CO3,HCO3,F-H2O six-component system at 25°C in the trona crystallization region (Na2CO3 · NaHCO3 · 2H2O) by the translation method are considered. Trona, which is one of the equilibrium solid phases of the title system at 25°C, is involved in equilibria that correspond to 14 invariant points, 37 monovariant curves, and 28 divariant fields. These data were used to construct a fragment of the phase equilibrium diagram of the title system in the trona crystallization region. 相似文献
45.
Film flows occur in many technical processes (e.g. coating techniques) as well as in nature. In this paper we establish a new analytical method in order to calculate both the velocity field and the surface shape of a two–dimensional gravity driven film flow of a Newtonian fluid down a periodically varying bottom topology. We discuss the special case of a sinusoidal bottom shape. 相似文献
46.
47.
Zikai Feng Monila Nadikudi Krystel L. Woolley Ayman L. Hemasa Sueanne Chear Jason A. Smith Nuri Gueven 《Molecules (Basel, Switzerland)》2021,26(5)
Short-chain quinones (SCQs) have been investigated as potential therapeutic candidates against mitochondrial dysfunction, which was largely thought to be associated with the reversible redox characteristics of their active quinone core. We recently reported a library of SCQs, some of which showed potent cytoprotective activity against the mitochondrial complex I inhibitor rotenone in the human hepatocarcinoma cell line HepG2. To better characterize the cytoprotection of SCQs at a molecular level, a bioactivity profile for 103 SCQs with different compound chemistries was generated that included metabolism related markers, redox activity, expression of cytoprotective proteins and oxidative damage. Of all the tested endpoints, a positive correlation with cytoprotection by SCQs in the presence of rotenone was only observed for the NAD(P)H:quinone oxidoreductase 1 (NQO1)-dependent reduction of SCQs, which also correlated with an acute rescue of ATP levels. The results of this study suggest an unexpected mode of action for SCQs that appears to involve a modification of NQO1-dependent signaling rather than a protective effect by the reduced quinone itself. This finding presents a new selection strategy to identify and develop the most promising compounds towards their clinical use. 相似文献
48.
Cagdas Gonen Mine Gungormusler Nuri Azbar 《Applied biochemistry and biotechnology》2012,168(8):2136-2147
In this study, pumice stone (PS), which is a vastly available material in Turkey, was evaluated as an alternative immobilization material in comparison to other commercially available immobilization materials such as glass beads and polyurethane foam. All immobilized bioreactors resulted in much better 1,3-propanediol production from waste glycerol in comparison to the suspended cell culture bioreactor. It was also demonstrated that the locally available PS material is as good as the commercially available immobilization material. The maximum volumetric productivity (8.5?g?L?1?h?1) was obtained by the PS material, which is 220?% higher than the suspended cell system. Furthermore, the immobilized bioreactor system was much more robust against cell washout even at very low hydraulic retention time values. 相似文献
49.
Mehmet Kabak Yal
in Elerman Vildan Güner Tahsin Nuri Durlu 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):e207-e208
In the title compound, C35H26ClNO, the four‐membered β‐lactam ring is essentially planar, with a maximum deviation of 0.012 (1) Å for the N atom. The C—C bond lengths in the β‐lactam ring are 1.591 (2) and 1.549 (2) Å. The two phenyl rings attached to the β‐lactam ring are nearly perpendicular to each other [83.2 (1)°]. 相似文献
50.
Enhancement of heat transfer to the fluid can be done by turbulence promoters such as attached fins to the pipe walls. In
this study, the flow field and the heat transfer rates were numerically investigated in a pipe with an internally attached
fin. Numerical simulations were conducted for four different types of fluids and for different fin heights and locations,
and as the Reynolds number was varied, the effects of the fin on Nusselt number and friction factors were investigated. For
all the Reynolds numbers considered in this study, the effect of fin location on the heat transfer rate and friction factor
was negligible. As the fin height was increased, the mean Nusselt number and the friction factor also increased in the turbulent
flow regimes. For low Prandtl number fluids (Pr = 0.011), the main heat transfer mode is conduction, and hence the mean Nusselt number slightly affected the flow rates. 相似文献