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131.
Schimmel u. Co. 《Fresenius' Journal of Analytical Chemistry》1923,62(10):411
Ohne Zusammenfassung 相似文献
132.
133.
3D DNA Origami Nanoparticles: From Basic Design Principles to Emerging Applications in Soft Matter and (Bio‐)Nanosciences 下载免费PDF全文
Sebastian Loescher Saskia Groeer Prof. Andreas Walther 《Angewandte Chemie (International ed. in English)》2018,57(33):10436-10448
Scaffold‐based lattice‐engineered 3D DNA origami is a powerful and versatile technique for the rational design and build‐up of arbitrarily structured and monodisperse DNA‐based 3D nanoobjects. Relying on the unsurpassed molecular programmability of sequence‐specific DNA hybridization, a long DNA single strand (termed scaffold) is assembled with many short single‐stranded oligomers (termed staples), which organize the scaffold into a 3D lattice in a single step, thereby leading to 3D nanoparticulate structures of the highest precision in high yields. Applications of 3D DNA origami are increasingly wide‐spread and interface with numerous fields of sciences, for example, anisometric or anisotropically functionalized nanoparticles, fundamental investigations of superstructure formation, biomedicine, (bio)physics, sensors, and optical materials. This Minireview discusses the fundamentals and recent advances from structure formation to selected applications, with a mission to promote cross‐disciplinary exchange. 相似文献
134.
Sturgeon RE Wahlen R Brandsch T Fairman B Wolf-Briche C Alonso JI González PR Encinar JR Sanz-Medel A Inagaki K Takatsu A Lalere B Monperrus M Zuloaga O Krupp E Amouroux D Donard OF Schimmel H Sejerøe-Olsen B Konieczka P Schultze P Taylor P Hearn R Mackay L Myors R Win T Liebich A Philipp R Yang L Willie S 《Analytical and bioanalytical chemistry》2003,376(6):780-787
The capabilities of National Metrology Institutes (NMIs—those which are members of the Comité Consultatif pour la Quantité de Matière (CCQM)of the CIPM) and selected outside "expert" laboratories to quantitate (C4H9)3Sn+ (TBT) in a prepared marine sediment were assessed. This exercise was sanctioned by the 7th CCQM meeting, April 4–6, 2001, as an activity of the Inorganic Analysis Working Group and was jointly piloted by the Institute for National Measurement Standards of the National Research Council of Canada (NRC) and the Laboratory of the Government Chemist (LGC), UK. A total of 11 laboratories submitted results (7 NMIs, and 4 external labs). Two external laboratories utilized a standard calibration approach based on a natural abundance TBT standard, whereas all NMIs relied upon isotope dilution mass spectrometry for quantitation. For this purpose, a species specific 117Sn-enriched TBT standard was supplied by the LGC. No sample preparation methodology was prescribed by the piloting laboratories and, by consequence, a variety of approaches was adopted by the participants, including mechanical shaking, sonication, accelerated solvent extraction, microwave assisted extraction and heating in combination with Grignard derivatization, ethylation and direct sampling. Detection techniques included ICP–MS (with GC and HPLC sample introduction), GC–MS, GC–AED and GC–FPD. Recovery of TBT from a control standard (NRCC CRM PACS-2 marine sediment) averaged 93.5±2.4% (n=14). Results for the pilot material averaged 0.680±0.015 µmol kg–1 (n=14; 80.7±1.8 µg kg–1) with a median value of 0.676 µmol kg–1. Overall, performance was substantially better than state-of-the-art expectations and the satisfactory agreement amongst participants permitted scheduling of a follow-up Key comparison for TBT (K-28), a Pilot intercomparison for DBT (P-43), and certification of the test sediment for TBT content and its release as a new Certified Reference Material (HIPA-1) with a TBT content of 0.679±0.089 µmol kg–1 (expanded uncertainty, k=2, as Sn) (80.5±10.6 µg kg–1).Electronic Supplementary Material Supplementary material is available in the online version of this article at . 相似文献
135.
136.
G N Kramer J Pauwels L Le Guern H Schimmel S Trapmann 《Fresenius' Journal of Analytical Chemistry》2001,370(2-3):142-146
In the execution of its mission to promote a common European measurement system in support of EU policies, IRMM's Reference Materials Unit is currently involved in preparation of proficiency-testing samples and candidate reference materials. Recent work related to bovine spongiform encephalopathy in cows, genetically modified organisms, and a variety of environmental materials is described. 相似文献
137.
P. E. R. Durigon D. F. S. Petri H. Drings Th. Schimmel M. Bruns 《Colloid and polymer science》2001,279(10):1013-1019
Films of immiscible blends of (PS) and poly(methyl methacrylate) (PMMA) were characterized by contact-angle measurements
with sessile drop and atomic force microscopy (AFM). These blends showed a linear dependence of the contact angles on the
composition, as predicted by Cassie's equation for ideal surfaces. The surface structure investigated by AFM showed low roughness
and phase-separation features. The ratio between the drop radius and the roughness amounted to the order of 104–105. This magnitude seemed to be sufficient to put the PS/PMMA films close to ideality. Upon sulfonation, the wettability and
the microscopic surface roughness of the PS/PMMA blends increased. The treatment with sulfuric acid yielded sulfonated PS
domains on the surface, causing an increase in the surface wettability. The SO3
− groups were evidenced by X-ray photoelectron spectroscopy. The sulfonation of the PS/PMMA blends enables the formation of
multiphase surfaces with hydrophobic, charged and polar domains.
Received: 11 December 2000 Accepted: 6 April 2001 相似文献
138.
J. Prokisch R. Zeleny S. Trapmann L. Le Guern H. Schimmel G. N. Kramer J. Pauwels 《Analytical and bioanalytical chemistry》2001,370(7):935-939
Homogeneity testing and the determination of minimum sample mass are an important part of the certification of reference
materials. The smallest theoretically achievable uncertainty of certified concentration values is limited by the concentration
distribution of analyte in the different particle size fractions of powdered biological samples. This might be of special
importance if the reference material is prepared by dry mixing, a dilution technique which is used for the production of the
new and third generation of genetically modified (GMO) plant certified reference materials. For the production of dry mixed
PMON 810 maize reference material a computer program was developed to calculate the theoretically smallest uncertainty for
a selected sample intake. This model was used to compare three differently milled maize samples, and the effect of dilution
on the uncertainty of the DNA content of GMO maize was estimated as well. In the case of a 50-mg sample mass the lowest achievable
standard deviation was 2% for the sample containing 0.1% GMO and the minimum deviation was less than 0.5% for the sample containing
5% GMO.
Received: 5 December 2000 / Revised: 14 March 2001 / Accepted: 19 March 2001 相似文献
139.
It has been shown that the concept of molar response, which is applicable to single ion monitoring of M+, can also be employed for ion trap MS/MS measurements, simplifying the determination of PCDD/PCDF by an extended IDA approach. 相似文献
140.
Gas chromatography-olfactometry analysis of the volatile compounds of two commercial Irish beef meats 总被引:1,自引:0,他引:1
The volatile flavour compounds of two commercial Irish beef meats (labelled as conventional and organic) were evaluated by gas chromatography-olfactometry and were identified by gas chromatography-mass spectrometry. The volatile compounds were isolated in a model mouth system. Gas chromatography-olfactometry was performed by a group of eight assessors using the detection frequency methodology. The odours of the detected compounds were described as well. Eighty-one volatile compounds were identified, 11 compounds of which possessed odour activity in the first beef sample and 14 of which in the second meat sample. Ten volatile flavour compounds were common to both: methanethiol, dimethyl sulphide, 2-butanone, ethyl acetate, 2- and 3-methylbutanal, an unknown compound, 2-octanone, decanal and benzothiazole. Two unknown compounds were only detected in the first sample while 2,3-pentanedione, 4-methyl-3-penten-2-one, 2-heptanone, dimethyl trisulphide and nonanal were only perceived in the second beef. Significant differences in terms of detection frequency, odour characteristics and in nature of the volatile flavour compounds were emphasised between the two samples. 相似文献