全文获取类型
收费全文 | 42篇 |
免费 | 1篇 |
专业分类
化学 | 27篇 |
力学 | 1篇 |
数学 | 2篇 |
物理学 | 13篇 |
出版年
2022年 | 3篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 4篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2004年 | 1篇 |
2002年 | 1篇 |
1998年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1941年 | 1篇 |
1918年 | 1篇 |
1899年 | 1篇 |
1897年 | 2篇 |
1894年 | 1篇 |
1890年 | 1篇 |
1888年 | 3篇 |
1885年 | 1篇 |
排序方式: 共有43条查询结果,搜索用时 9 毫秒
1.
B. Keiser 《Fresenius' Journal of Analytical Chemistry》1941,122(5-6):229
Ohne Zusammenfassung 相似文献
2.
3.
Two boundary-value problems in plane geometry, modeling the field and current distribution produced by moving sources of magnetic
field (fluxons) in surrounding normal metals, are solved analytically. In the first case a fluxon moves with a constant velocity
in a superconducting plane separated by a vacuum gap from a half space filled with a metal having a low electrical conductivity.
In the second case the half space is replaced by a thin metal layer of high conductivity. The problems are solved by perturbation
techniques, the Fourier integral transform, and the Parseval identity. The latter is used to calculate the power dissipated
in the metal. An estimate of the power dissipation is needed in order to calculate certain torques of magnetic origin in the
Gravity Probe B project.
Zh. Tekh. Fiz. 68, 1–8 (February 1998) 相似文献
4.
Keiser T Höllriegl V Giussani A Oeh U 《Isotopes in environmental and health studies》2011,47(2):238-252
Thermal ionisation mass spectrometry (TIMS) method has been developed for the simultaneous detection of different cerium isotopes in biological samples (i.e., blood and urine) at very low concentrations. The work has been done in the frame of a biokinetic study, where different stable cerium isotopes have been administered orally and intravenously as tracers to the human body. In order to develop an appropriate detection method for the tracers in the biological samples, an optimum sample preparation technique has been set and adapted to the specific requirements of the analysis technique used, i.e., TIMS. For sample evaporation and ionisation, the double tantalum filament technique showed the best results. The ions produced were simultaneously collected on a secondary electron multiplier so that the isotopic ratios of the cerium isotopes in the biological samples could be measured. The technique has been optimised for the determination of cerium down to 1?ng loaded on the evaporation filament corresponding to cerium concentrations of down to 1?ng?ml(-1) in the blood or urine samples. It has been shown that the technique is reliable in application and enables studies on cerium metabolism and biokinetics in humans without employing radioactive tracers. 相似文献
5.
Fast Photoresponse and Long Lifetime UV Photodetectors and Field Emitters Based on ZnO/Ultrananocrystalline Diamond Films 下载免费PDF全文
Adhimoorthy Saravanan Prof. Dr. Bohr‐Ran Huang Jun‐Cheng Lin Gerd Keiser Prof. Dr. I‐Nan Lin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(45):16017-16026
We have designed photodetectors and UV field emitters based on a combination of ZnO nanowires/nanorods (ZNRs) and bilayer diamond films in a metal–semiconductor–metal (MSM) structure. The ZNRs were fabricated on different diamond films and systematic investigations showed an ultra‐high photoconductive response from ZNRs prepared on ultrananocrystalline diamond (UNCD) operating at a lower voltage of 2 V. We found that the ZNRs/UNCD photodetector (PD) has improved field emission properties and a reduced turn‐on field of 2.9 V μm?1 with the highest electron field emission (EFE) by simply illuminating the sample with ultraviolet (UV) light. The photoresponse (Iphoto/Idark) behavior of the ZNRs/UNCD PD exhibits a much higher photoresponse (912) than bare ZNRs (229), ZNRs/nanocrystalline diamond (NCD; 518), and ZNRs/microcrystalline diamond (MCD; 325) under illumination at λ=365 nm. A photodetector with UNCD films offers superior stability and a longer lifetime compared with carbon materials and bare ZNRs. The lifetime stability of the ZNRs/UNCD‐based device is about 410 min, which is markedly superior to devices that use bare ZNRs (92 min). The ZNRs/UNCD PD possesses excellent photoresponse properties with improved lifetime and stability; in addition, ZNRs/UNCD‐based UV emitters have great potential for applications such as cathodes in flat‐panel displays and microplasma display devices. 相似文献
6.
Mthandazo Dube Dayma Llanes Mohamad Saoud Robert Rennert Peter Imming Ccile Hberli Jennifer Keiser Norbert Arnold 《Molecules (Basel, Switzerland)》2022,27(9)
Neglected tropical diseases affect the world’s poorest populations with soil-transmitted helminthiasis and schistosomiasis being among the most prevalent ones. Mass drug administration is currently the most important control measure, but the use of the few available drugs is giving rise to increased resistance of the parasites to the drugs. Different approaches are needed to come up with new therapeutic agents against these helminths. Fungi are a source of secondary metabolites, but most fungi remain largely uninvestigated as anthelmintics. In this report, the anthelmintic activity of Albatrellus confluens against Caenorhabditis elegans was investigated using bio-assay guided isolation. Grifolin (1) and neogrifolin (2) were identified as responsible for the anthelmintic activity. Derivatives 4–6 were synthesized to investigate the effect of varying the prenyl chain length on anthelmintic activity. The isolated compounds 1 and 2 and synthetic derivatives 4–6, as well as their educts 7–10, were tested against Schistosoma mansoni (adult and newly transformed schistosomula), Strongyloides ratti, Heligmosomoides polygyrus, Necator americanus, and Ancylostoma ceylanicum. Prenyl-2-orcinol (4) and geranylgeranyl-2-orcinol (6) showed promising activity against newly transformed schistosomula. The compounds 1, 2, 4, 5, and 6 were also screened for antiproliferative or cytotoxic activity against two human cancer lines, viz. prostate adenocarcinoma cells (PC-3) and colorectal adenocarcinoma cells (HT-29). Compound 6 was determined to be the most effective against both cell lines with IC50 values of 16.1 µM in PC-3 prostate cells and 33.7 µM in HT-29 colorectal cells. 相似文献
7.
Betelhem Sirak Kaleab Asres Asrat Hailu Mthandazo Dube Norbert Arnold Cecile Hberli Jennifer Keiser Peter Imming 《Molecules (Basel, Switzerland)》2021,26(24)
Leishmaniasis and schistosomiasis are neglected tropical diseases (NTDs) infecting the world’s poorest populations. Effectiveness of the current antileishmanial and antischistosomal therapies are significantly declining, which calls for an urgent need of new effective and safe drugs. In Ethiopia fresh leaves of Ranunculus multifidus Forsk. are traditionally used for the treatment of various ailments including leishmaniasis and eradication of intestinal worms. In the current study, anemonin isolated from the fresh leaves of R. multifidus was assessed for its in vitro antileishmanial and antischistosomal activities. Anemonin was isolated from the hydro-distilled extract of the leaves of R. multifidus. Antileishmanial activity was assessed on clinical isolates of the promastigote and amastigote forms of Leishmania aethiopica and L. donovani clinical isolates. Resazurin reduction assay was used to determine antipromastigote activity, while macrophages were employed for antiamastigote and cytotoxicity assays. Antischistosomal assays were performed against adult Schistosoma mansoni and newly transformed schistosomules (NTS). Anemonin displayed significant antileishmanial activity with IC50 values of 1.33 nM and 1.58 nM against promastigotes and 1.24 nM and 1.91 nM against amastigotes of L. aethiopica and L. donovani, respectively. It also showed moderate activity against adult S. mansoni and NTS (49% activity against adult S. mansoni at 10 µM and 41% activity against NTS at 1 µM). The results obtained in this investigation indicate that anemonin has the potential to be used as a template for designing novel antileishmanial and antischistosomal pharmacophores. 相似文献
8.
Ohne Zusammenfassung 相似文献
9.
10.