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71.
Krizkova S Ryvolova M Hynek D Eckschlager T Hodek P Masarik M Adam V Kizek R 《Electrophoresis》2012,33(12):1824-1832
Zinc(II) as the only transition metal lacking redox activity is an essential part of approximately 10% proteins as a cofactor of these proteins. Considering the fact that there are numerous zinc(II) containing proteins, proteomics and metallomics studies aimed on them require accurate methods for preparation of real biological samples prior to their subsequent analysis using 2DE and MS. For this purpose, we suggested a new method based on chicken anti-zinc antibodies and magnetizable particles. Antibodies were covalently immobilized to the surface of paramagnetic beads activated with tosyl group. Binding of the antibody to the beads was confirmed by secondary anti-chicken antibody conjugated with horseradish peroxidase. The immunoextraction conditions, such as concentration of the beads (6-18 μg/mL of the sample), time of immunoextraction (6-34 min), pH and composition of the elution buffer, and time of extraction (48-300 s) were optimized. Subsequently, zinc proteins were extracted from human plasma and total concentration of zinc was monitored by electrochemical detection in the extracts. Under optimal conditions it was possible to monitor the proteins and zinc removal from the sample by chip CE, SDS-PAGE, and indirectly using electrochemistry. 相似文献
72.
John Texter Vivek Arjunan Vasantha Rene Crombez Rafael Maniglia Lisa Slater Thomas Mourey 《Macromolecular rapid communications》2012,33(1):69-74
The controlled atom transfer radical polymerization of an ionic liquid, 1‐(11‐acryloylundecyl)‐3‐methyl imidazolium bromide (ILBr), from both ends of a telechelic poly(propylene oxide) (PPO) macroinitiator, end‐functionalized with bromoisobutyryloyl is reported. The resulting highly water‐soluble triblock, poly(ILBr‐b‐PO‐b‐ILBr) is multistimuli responsive. This new class of triblocks exhibits classical surface activity in lowering surface tension at the air–water interface and in modifying wetting in waterborne coatings. It also immunizes model colloids against coagulation induced by Debye–Hückel (indifferent electrolyte) electrostatic screening. Further, sol–gel thermoreversibility is unexpectedly found as an additional form of stimuli responsiveness. 相似文献
73.
Rene Hornung Mathias K. Fehr Jill Monti-Frayne Tatiana B. Krasieva Bruce J. Tromberg Michael W. Berns Yona Tadir 《Photochemistry and photobiology》1999,70(4):624-629
Photodynamic therapy (PDT) uses light to activate a photosensitizer that has been absorbed or retained preferentially by cancer cells after systemic administration. The first pegylated photosensitizer, tetrakis-(m-methoxypolyethylene glycol) derivative of 7,8-dihydro-5,10,15,20-tetrakis(3-hydroxyphenyl)-21,23-[H]-porphyrin (PEG-m-THPC), was evaluated to target selectively unresectable pelvic ovarian cancer bulks. Our goals were two-fold: (1) to establish an ovarian cancer model suitable for the development of debulking techniques and (2) to characterize the pharmacokinetics and tumor selectivity of PEG-m-THPC by fluorescence microscopy. NuTu-19 ovarian cancer cells were injected into the caudal part of the right psoas muscle of Fisher rats. Five weeks later, 30 mg/kg body weight of PEG-m-THPC was injected intravenously. Necropsy was performed between 4 and 10 days following drug application, and fluorescence of the tumor and various abdominal organs was measured. All rats developed bulky pelvic tumors with an average diameter of 2.6 cm (+/- 0.6 SD). Tumor masses were encompassing and infiltrating pelvic organs in a similar manner to ovarian cancers in humans. Fluorescence of cancer tissue was maximal 8-10 days following drug application. At 8 days, the tumor-to-tissue ratio was 40:1 (+/- 12 SE) for most abdominal organs. We conclude that this tumor model may be used for the study of new pelvic debulking techniques, and that the tumor selectivity of PEG-m-THPC is exceptionally high 8 days after drug application. Based on these data, we are currently developing a PDT-based minimally invasive debulking technique for advanced ovarian cancer. 相似文献
74.
75.
Viktor A. Tafeenko Olga V. Kaukova Rene Peschar Aleksandr V. Petrov Leonid A. Aslanov 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):m421-m423
The crystal structure of the title potassium salt, K+·C8HN4O2−, of the organic anion 3‐cyano‐4‐(dicyanomethylene)‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olate shows that the dicyanomethylene moiety is able to accept an electron in the same way as does tetracyanoethylene, to yield the novel product. The organic anion is nearly planar, with deviations caused by steric crowding among the exocyclic cyano groups. The K+ cations lie within tricapped trigonal prisms that stack to form channels. The three‐dimensional structure is completed by the formation of hydrogen‐bonded chains by the anions. 相似文献
76.
77.
Zhen Yang Yujing Guo Prof. Dr. Rene M. Koenigs 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(27):6703-6706
Sigmatropic rearrangement reactions constitute one of the most fundamental reactions of carbenes. While state-of-the-art synthetic methods require the use of expensive precious metal catalysts, the application of visible light for the photolysis of α-aryldiazoacetates is much less investigated and provides an operationally simple entry to carbenes under mild reaction conditions. Herein, we report on blue-light induced sigmatropic rearrangement reactions of sulfur compounds with α-aryldiazoacetates. This process, depending on the substitution pattern of the sulfide, opens up formal insertion reactions of carbenes into S−N, S−C, or C−H bonds. 相似文献
78.
Nonlinear Dynamics - We study the Kuramoto–Sakaguchi model composed by N identical phase oscillators symmetrically coupled. Ranging from local (one-to-one, $$R=1$$ ) to global (all-to-all,... 相似文献
79.
Wolfgang Bauer Rene Bellwied John Harris Gary Westfall 《Acta Physica Hungarica A》2004,21(2-4):99-100
80.
Digital image processing is applied to X-ray element maps and back-scattered electron (BSE) images obtained with scanning
electron microscopy-energy dispersive X-ray analysis (SEM-EDX), to quantify and identify salts and porosity with depth in
porous media. Until now, only salt chemical composition with depth has been characterised and salt mineral composition inferred,
so that no salt quantification was possible. The method we present can be used stand-alone or integrated with other techniques
to fill certain gaps in our knowledge. It can be used to quantify texture and porosity of clay minerals, with implications
in petroleum research. Also, salts may be identified and quantified with depth in porous media; this is important when selecting
among salt extraction procedures in order to conserve cultural heritage. Finally, the method can help in interpreting salt
weathering processes and links between stone decay forms at different scales, with consequences for geomorphology.
To demonstrate the method, salt and pore percentages with depth are determined in two limestone types from monuments in the
Aunis province, SW France: i) Crazannes sparite, showing alveolisation and black crust, and ii) La Pallice micrite, suffering
from micro-delamination. In most of the micrites no salts are identified. Porosity data show that micro-fissures are confined
between the surface and 9 mm depth in LPAM5, the only micrite with loading salts with depth (NaCl = 1.9% at the surface versus
1.4% at 18 mm; and Na2SO4 · H2O and MgCl2 ∼ 0.02% in the first 3 mm). In the sparites, those samples with no crust display an alveolisation zone with lower porosity
and higher diversity and percentage of salts. In CRZM6, the stone crust-alveolisation front lies at a depth of 9 mm. In the
crust, porosity is lower than in the alveolisation zone (12%). Salt concentration, by contrast, is higher in the crust (2.91%
versus 0.14% in the alveolisation zone).
Received September 1, 2000 Revision November 2, 2001 相似文献