全文获取类型
收费全文 | 118篇 |
免费 | 3篇 |
专业分类
化学 | 43篇 |
晶体学 | 1篇 |
力学 | 3篇 |
数学 | 41篇 |
物理学 | 33篇 |
出版年
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 8篇 |
2014年 | 3篇 |
2013年 | 11篇 |
2012年 | 3篇 |
2011年 | 7篇 |
2010年 | 2篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1966年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有121条查询结果,搜索用时 203 毫秒
31.
The suitability of acid- and enzymatically hydrolyzed birch hemicellulose as biotechnical raw material was studied usingCluconobacter oxydans, Fusarium oxysporum, andCandida utilis for production of xylonic acid, ethanol, and SCP, respectively. The fermentabilities of both hydrolyzates were rather similar
and inhibition was evident in all cases at xylose concentrations of 257–30 g/L and higher. Potential identified fermentation
inhibitors were the lignin-derived compounds sinapyl alcohol, coniferyl alcohol, vanillin, and syringaldehyde and the sugar
degradation products furfural and 5-hydroxymethyl furfural. 相似文献
32.
Eveliina Markkula Harri M. Salo Kaisa Rikalainen Ilmari E. Jokinen 《Photochemistry and photobiology》2009,85(1):347-352
The effects of long-term, low-dose ultraviolet B (UVB) radiation on immune functions of two fish species representing different taxonomic groups, carp ( Cyprinus carpio ) and rainbow trout ( Oncorhynchus mykiss ), were assessed in this study. The fish were exposed to 7, 20 or 60 mJ cm−2 UVB three times per week, for 6 weeks. In carp, UVB exposure affected the respiratory burst activity of blood and head kidney phagocytes, differential blood leukocyte counts and blood chemistry. Phytohemagglutinin (PHA)-stimulated in vitro proliferation responses of blood and head kidney lymphocytes, however, remained unchanged. Rainbow trout tolerated the irradiations with fewer alterations, but significant changes were detected in blood chemistry and hematocrits of the irradiated fish. These results indicate that long-term exposure to low doses of UVB induces immunomodulation in fish, and that there are species-specific differences in sensitivity to irradiation. 相似文献
33.
Beale AM van der Eerden AM Kervinen K Newton MA Weckhuysen BM 《Chemical communications (Cambridge, England)》2005,(24):3015-3017
The potential of combined operando UV-Vis/Raman/XAFS has been explored by studying the active site and deactivation mechanism of silica- and alumina-supported molybdenum oxide catalysts under propane dehydrogenation conditions. 相似文献
34.
We discuss lepton pair and real photon emission from quark-gluon plasma, which is very likely to be formed in high energy nucleus-nucleus collisions. Measurement of pair production crosssection will provide one with accurate information of the temperature of this plasma. 相似文献
35.
The dual properties of the inclusive reaction π?p → pX are studied over a wide energy range by exploiting the scaling behaviour. Semi-local duality is found to be well satisfied. An energy-dependent triple-Regge analysis reveals a strong triple-pomeron coupling. There is some evidence of an abnormal component in which diffractively produced resonances are dual to pomeron exchange. Combining duality with factorization leads to relations between production cross sections of meson and baryon resonances in πp and pp collisions, which are compatible with existing experimental data. 相似文献
36.
J.R. Fry R. Matthews H. Muirhead C. Brankin A. Angelopoulos A. Apostolakis P. Theocharopoulos G. Vasiliades T.A. Filippas E. Simopoulou P. Tsilimigras A. Vayaki B. Buschbeck D. Dallman G. Otter P. Schmid H.I. Miettinen 《Nuclear Physics B》1973,58(2):420-428
We present double differential cross sections for the reactions K? + p → π± + anything at 8.25 GeV/c. Using published data for reactions K+ + p→ π? + anything and p + p → π+ anything we predict the differential cross sections for γ + p → π? + anything, π? + p → π? + anything and π? + p → π+ + anything in the target fragmentation region based on factorisation of the pomeron and Regge trajectories. Our predictions agree with the experimental data and support the hypothesis of factorisation of the Regge trajectories in the target fragmentation region. 相似文献
37.
Vesa Ojalehto Kaisa Miettinen Timo Laukkanen 《Computational Optimization and Applications》2014,58(3):757-779
Interactive multiobjective optimization methods have provided promising results in the literature but still their implementations are rare. Here we introduce a core structure of interactive methods to enable their convenient implementation. We also demonstrate how this core structure can be applied when implementing an interactive method using a modeling environment. Many modeling environments contain tools for single objective optimization but not for interactive multiobjective optimization. Furthermore, as a concrete example, we present GAMS-NIMBUS Tool which is an implementation of the classification-based NIMBUS method for the GAMS modeling environment. So far, interactive methods have not been available in the GAMS environment, but with the GAMS-NIMBUS Tool we open up the possibility of solving multiobjective optimization problems modeled in the GAMS modeling environment. Finally, we give some examples of the benefits of applying an interactive method by using the GAMS-NIMBUS Tool for solving multiobjective optimization problems modeled in the GAMS environment. 相似文献
38.
Gianluca Destro Kaisa Horkka Olivier Loreau David‐Alexandre Buisson Lee Kingston Antonio Del Vecchio Magnus Schou Charles S. Elmore Frdric Taran Thibault Cantat Davide Audisio 《Angewandte Chemie (International ed. in English)》2020,59(32):13490-13495
A transition‐metal‐free carbon isotope exchange procedure on phenyl acetic acids is described. Utilizing the universal precursor CO2, this protocol allows the carbon isotope to be inserted into the carboxylic acid position, with no need of precursor synthesis. This procedure enabled the labeling of 15 pharmaceuticals and was compatible with carbon isotopes [14C] and [13C]. A proof of concept with [11C] was also obtained with low molar activity valuable for distribution studies. 相似文献
39.
Synchronous approach in interactive multiobjective optimization 总被引:8,自引:0,他引:8
We introduce a new approach in the methodology development for interactive multiobjective optimization. The presentation is given in the context of the interactive NIMBUS method, where the solution process is based on the classification of objective functions. The idea is to formulate several scalarizing functions, all using the same preference information of the decision maker. Thus, opposed to fixing one scalarizing function (as is done in most methods), we utilize several scalarizing functions in a synchronous way. This means that we as method developers do not make the choice between different scalarizing functions but calculate the results of different scalarizing functions and leave the final decision to the expert, the decision maker. Simultaneously, (s)he obtains a better view of the solutions corresponding to her/his preferences expressed once during each iteration.In this paper, we describe a synchronous variant of the NIMBUS method. In addition, we introduce a new version of its implementation WWW-NIMBUS operating on the Internet. WWW-NIMBUS is a software system capable of solving even computationally demanding nonlinear problems. The new version of WWW-NIMBUS can handle versatile types of multiobjective optimization problems and includes new desirable features increasing its user-friendliness. 相似文献
40.
Michiko Watanabe Midori Hitomi Kathy van der Wee Florence Rothenberg Steven A Fisher Robert Zucker Kathy K H Svoboda Edie C Goldsmith Kaisa M Heiskanen Anna-Liisa Nieminen 《Microscopy and microanalysis》2002,8(5):375-391
Programmed cell death or apoptosis occurs in many tissues during normal development and in the normal homeostasis of adult tissues. Apoptosis also plays a significant role in abnormal development and disease. Increased interest in apoptosis and cell death in general has resulted in the development of new techniques and the revival of old ones. Each assay has its advantages and disadvantages that can render it appropriate and useful for one application, but inappropriate or difficult to use in another. Understanding the strengths and limitations of the assays would allow investigators to select the best methods for their needs. 相似文献