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41.
Niklaus Wirth 《BIT Numerical Mathematics》1969,9(4):362-386
An attempt to devise a methodology of compiler design is described, and an outline is given for a possible course on this subject. The theoretical basis is formed by the concepts of phrase-structure language, finite-state- and stack-acceptor, and transducer. As their extension capable of processing context-dependent elements of languages, a so-called Table-Transducer is postulated, and it serves as the core-algorithm upon which compilers are based. The developed theory and method of compiler construction is applied to an example of a simple programming language. 相似文献
42.
Two new bufadienolides, isolated from Ch'an Su, are proved to be 19-oxo-cinobufagin (III) and 19-oxo-cinobufotalin (V), respectively. 相似文献
43.
Summary For the solutions of a system of ordinary differential equations restricted Liapunov stability and the notion of Liapunov stable sets are discussed, in particular for separable and almost separable Hamiltonian systems. We consider stabilization procedures, i.e. modifications of the original differential equations such that the solutions of the modified are Liapunov stable and thus the new system is better suited for numerical integration. In this paper some theoretical aspects rather than numerical methods are pointed out.
Zusammenfassung Wir diskutieren die eingeschränkte Liapunov-Stabilität von Lösungen eines Systems von gewöhnlichen Differentialgleichungen und den Begriff der Liapunov-stabilen Menge, insbesondere für separable und fastseparable Hamilton'sche Systeme. Dann betrachten wir Stabilisierungs-methoden, d.h. Abänderungen der Differentialgleichungen, die bewirken, dass die Lösungen des modifizierten Systems Liapunov-stabil sind und die numerische Integration dadurch verbessert wird. Das Gewicht liegt auf der Klärung von einigen theoretischen Zusammenhängen und nicht auf der Erläuterung von numerischen Methoden.相似文献
44.
Wetter C Gierlich J Knoop CA Müller C Schulte T Studer A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(5):1156-1166
The synthesis of new six- and seven-membered cyclic alkoxyamines bearing ethyl groups at the alpha-N position of the alkoxyamines is described. The key step in the synthesis of the sterically hindered six-membered cyclic alkoxyamines is a Wadsworth-Horner-Emmons olefination with bisphosphonate 1. The seven-membered cyclic alkoxyamines were prepared from the corresponding six-membered keto alkoxyamines by ring-enlargement with trimethylsilyl(TMS)-diazomethane. The use of the new alkoxyamines as regulators/initiators for radical polymerization is discussed. Efficient controlled and living polymerization of styrene and n-butyl acrylate was obtained with the six-membered tetraethyl alkoxyamine 13. Controlled polymerizations can be conducted even at 90 degrees C. In addition, alkoxyamine 13 can be used for the preparation of AB diblock and ABA triblock copolymers with narrow polydispersities. The influence of the replacement of methyl groups in the alpha-position of the N atom in cyclic alkoxyamines by larger ethyl groups on the styrene polymerization (reaction time, PDI, kinetics of the C-O bond homolysis) is discussed. In addition, thermal decomposition of the new alkoxyamines was studied. Furthermore, the synthesis of N,N-bissilylated alkoxyamines is described. The silylated alkoxyamines are not suitable as regulators/initiators for the controlled/living radical polymerization. The C-O bonds in silylated alkoxyamines are stronger than the C-O bonds in analogous N,N-dialkylated alkoxyamines. The experimental results are verified by calculations with Gaussian 98 (A. 9). 相似文献
45.
N.U. Wetter 《Applied physics. B, Lasers and optics》2007,86(3):515-518
We report on the performance of a commercial, non-AR-coated diode laser bar of 20 W output power, consisting of 20 emitters,
which uses an external cavity to achieve tunable, dual-wavelength emission. The separation between the wavelength peaks can
be continuously tuned from 0 nm to 5 nm. An output power of 2.9 W is achieved at 3.7 nm peak-to-peak separation and higher
powers are achieved for less separation. This is the highest dual wavelength output power reported so far using a standard
diode laser array.
PACS 42.55.Px; 42.60.-v; 42.60.Da; 42.60.Fc 相似文献
46.
47.
Viktoriia Postupalenko Lo Marx David Viertl Nadge Gsponer Natalia Gasilova Thibaut Denoel Niklaus Schaefer John O. Prior Gerrit Hagens Frdric Lvy Patrick Garrouste Jean-Manuel Segura Origne Nyanguile 《Chemical science》2022,13(14):3965
Antibodies are an attractive therapeutic modality for cancer treatment as they allow the increase of the treatment response rate and avoid the severe side effects of chemotherapy. Notwithstanding the strong benefit of antibodies, the efficacy of anti-cancer antibodies can dramatically vary among patients and ultimately result in no response to the treatment. Here, we have developed a novel means to regioselectively label the Fc domain of any therapeutic antibody with a radionuclide chelator in a single step chemistry, with the aim to study by SPECT/CT imaging if the radiolabeled antibody is capable of targeting cancer cells in vivo. A Fc-III peptide was used as bait to bring a carbonate electrophilic site linked to a metal chelator and to a carboxyphenyl leaving group in close proximity with an antibody Fc nucleophile amino acid (K317), thereby triggering the covalent linkage of the chelator to the antibody lysine, with the concomitant release of the carboxyphenyl Fc-III ligand. Using CHX-A′′-DTPA, we radiolabeled trastuzumab with indium-111 and showed in biodistribution and imaging experiments that the antibody accumulated successfully in the SK-OV-3 xenograft tumour implanted in mice. We found that our methodology leads to homogeneous conjugation of CHX-A′′-DTPA to the antibody, and confirmed that the Fc domain can be selectively labeled at K317, with a minor level of unspecific labeling on the Fab domain. The present method can be developed as a clinical diagnostic tool to predict the success of the therapy. Furthermore, our Fc-III one step chemistry concept paves the way to a broad array of other applications in antibody bioengineering.A method is reported to attach a radionuclide chelator in a single step chemistry to the Fc domain of any therapeutic antibody. 相似文献
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50.
Based on chemical and NMR. evidence structure 1 is assigned to the cardioactive scillicyanoside isolated from white squill. 相似文献