全文获取类型
收费全文 | 231篇 |
免费 | 2篇 |
专业分类
化学 | 195篇 |
晶体学 | 2篇 |
数学 | 1篇 |
物理学 | 35篇 |
出版年
2022年 | 13篇 |
2021年 | 15篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 10篇 |
2014年 | 5篇 |
2013年 | 5篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 4篇 |
2007年 | 9篇 |
2006年 | 15篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 7篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 5篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1965年 | 1篇 |
排序方式: 共有233条查询结果,搜索用时 15 毫秒
81.
M. Kowalska S. Naimi J. Agramunt A. Algora G. Audi D. Beck B. Blank K. Blaum Ch. B?hm M. Breitenfeldt E. Estevez L. M. Fraile S. George F. Herfurth A. Herlert A. Kellerbauer D. Lunney E. Minaya-Ramirez D. Neidherr B. Olaizola K. Riisager M. Rosenbusch B. Rubio S. Schwarz L. Schweikhard U. Warring 《The European Physical Journal A - Hadrons and Nuclei》2009,42(3):351-359
With the Penning trap mass spectrometer ISOLTRAP, located at ISOLDE/CERN, preparatory work has been performed towards mass and decay studies on neutron-rich Hg and Tl isotopes beyond N = 126 . The properties of these isotopes are not well known because of large isobaric contamination coming mainly from surface-ionised Fr. Within the studies, production tests using several target-ion source combinations were performed. It was furthermore demonstrated around mass number A = 209 that the resolving power required to purify Fr is achievable with ISOLTRAP. In addition, masses of several isobaric contaminants, 211-213Fr and 211Ra , were determined with a three-fold improved precision. The results influence masses of more than 20 other nuclides in the 208Pb region. 相似文献
82.
Ewa Kowalska Magorzata Ziarno Adam Ekielski Tomasz elaziski 《Molecules (Basel, Switzerland)》2022,27(10)
Probiotics and probiotic therapy have been rapidly developing in recent years due to an increasing number of people suffering from digestive system disorders and diseases related to intestinal dysbiosis. Owing to their activity in the intestines, including the production of short-chain fatty acids, probiotic strains of lactic acid bacteria can have a significant therapeutic effect. The activity of probiotic strains is likely reduced by their loss of viability during gastrointestinal transit. To overcome this drawback, researchers have proposed the process of microencapsulation, which increases the resistance of bacterial cells to external conditions. Various types of coatings have been used for microencapsulation, but the most popular ones are carbohydrate and protein microcapsules. Microencapsulating probiotics with vegetable proteins is an innovative approach that can increase the health value of the final product. This review describes the different types of envelope materials that have been used so far for encapsulating bacterial biomass and improving the survival of bacterial cells. The use of a microenvelope has initiated the controlled release of bacterial cells and an increase in their activity in the large intestine, which is the target site of probiotic strains. 相似文献
83.
Szymon Poliski Patrycja Topka Magorzata Taska Sylwia Kowalska Sylwester Czaplicki Aleksandra Szydowska-Czerniak 《Molecules (Basel, Switzerland)》2022,27(21)
The aim of this study was to optimize the grinding process parameters (mesh size of grinder sieve (X1), the peripheral velocity of the grinding wheels (X2)), and the storage time (X3) of ground ginger rhizome and nutmeg to obtain ethanol and ethanol-water extracts with improved antioxidant properties. The optimal conditions were estimated using response surface methodology (RSM) based on a three-variable Box–Behnken design (BBD) in order to maximize the antioxidant capacity (AC) determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods, and the total phenolic content (TPC) was determined by the Folin–Ciocalteu (F–C) method in spice extracts. Additionally, the phenolic acid profiles in extracts from optimized conditions were analyzed using ultra-performance liquid chromatography (UPLC). It was found that the optimal preparation conditions for antioxidant extraction were dependent on the spice source and solvent type. The best antioxidant properties in nutmeg extracts were achieved for X1 = 1.0 mm, X2 = 40–41 Hz and X3 = 7 days, whereas the optimized parameters for ginger extracts were more varied (1.0–2.0 mm, 43–50 Hz and 1–9 days, respectively). The ginger extracts contained 1.5–1.8 times more phenolic acids, and vanillic, ferulic, gallic, and p-OH-benzoic acids were dominant. In contrast, the nutmeg extracts were rich in protocatechuic, vanillic, and ferulic acids. 相似文献
84.
Grygierczyk Gabriela Wasilewski Janusz Witkowska Magdalena Kowalska Teresa 《平面色谱法杂志一现代薄层色谱法》2003,16(1):11-14
JPC – Journal of Planar Chromatography – Modern TLC - This paper focuses on the use of complexation liquid chromatography (in its TLC mode) to investigate eleven monosulfides. In the... 相似文献
85.
The 1-dodecene-lauryl alcohol bicomponent system was investigated as an exemplary one, able to form the hydrogen-bonded mixed multimers, involving the olefinic double bond π-electrons. We applied the following analytical techniques: IR spectroscopy, dielectric permeativity measurements, and examinations taking advantage of the cellulose sorbents. 相似文献
86.
P. Byszewski Z. Klusek S. Pierzgalski S. Datta E. Kowalska M. Pop
awska 《Journal of Electron Spectroscopy and Related Phenomena》2003,130(1-3):25-32
The C60ONCFn cycloadduct (Fn=ferrocene) was prepared in the reaction between C60 and ferrocene oxime, the ferrocene derivative was bound to C60 at the 6–6 bond by a heterocyclic oxygen–nitrogen–carbon ring; the compound was stable in air. The compound dissolved in dichloroethane was deposited on HOPG and observed by UHV STM/STS methods. The molecules of C60ONCFn formed several-microns-long straight chains with clearly visible adducted groups pointing to one side of the chain. The STM/STS observations are discussed within the terms of semiempirical quantum chemical molecular modeling. 相似文献
87.
T. Kowalska 《Chromatographia》1982,15(10):650-652
Summary An effort was undertaken to elucidate the chromatographic behaviour of higher fatty alcohols and acids on Whatman No. 2 paper. A model of the dipole association was assumed, aiming to simply describe the intermolecular interactions between a molecule of the chromatographed substance and the sorbent monolayer. The thermodynamic relationships correspond to the empirical relationships, established during the studies. 相似文献
88.
A comparison was performed of the selected glycols, i.e., 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol, in respect of their ability to form intramolecular hydrogen bonds. The following analytical techniques were employed: ir absorption spectroscopy and a new method taking advantage of chromatographic paper. 相似文献
89.
Małgorzata Kowalska Magdalena Woźniak Anna Krzton-Maziopa Serge Tavernier Łukasz Pazdur Anna Żbikowska 《Journal of Dispersion Science and Technology》2019,40(2):192-205
The aim of this work was to obtain and evaluate the stability of new emulsion systems, in which diacylglycerols derived from enzymatic interesterification of mutton tallow with hemp oil were used as emulsifiers. In order to achieve a higher content of the polar fat fraction in the final fat blend, a different amount of water was added to the reaction mixtures. The modified fats with a mixture of mono and diacylglycerols served as a fat base for emulsions. Based on the results of Turbiscan test, the droplet size, emulsion texture, and studies of rheological properties, it was found that addition of water to the reaction mixture in the range of 1.00–1.25%, wt./wt., caused the formation of a sufficient amount of emulsifiers stabilizing the dispersion system.
The novelty of this work was to determine the optimal amount of water added to the interesterification of mutton tallow with vegetable oil, ensuring the synthesis of a high-efficiency emulsifying system. Another new aspect of this work was to show that the diacylglycerols obtained during such fat modification constitute effective emulsifiers for new stable emulsion systems that may find potential use as food emulsions (dressings) or cosmetic products dedicated to sensitive skin. 相似文献
90.
Summary The dependence of specific retention by a binary stationary phase in GC can be expressed as the sum of the products of the specific retention of the pure components times their respective volume fractions. In this study, however, one component has a site, which is not only mainly responsible for the selectivity, but also participates in strong self-association. This requires introduction of a concentration-dependent factor (x) in the corresponding term of the equation correlating Vg
mix
x
with x. In the GC resolution of N-trifluoroacetyl-amino acid isopropyl esters on a binary phase, N-lauroyl-L-amino t-butyl amide-squalane, data for the values of x were obtained.Adapting a previously developed LC retention model to the above GC data, an equation was derived for the dependence of x on the weight fraction (x) of the selector, namely x=1/x. This relationship permits calculation of retention volumes on the binary phase for a given x, as well as corresponding resolution coefficients of enantiomeric amino acid derivatives with generally excellent agreement with experiment. The chirality of the system is not relevant to application of the equation. 相似文献