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91.
Smith Verein für chemische Industrie Romijn Blank Finkenbeiner Jorissen und A. Vanino 《Fresenius' Journal of Analytical Chemistry》1900,39(1):60-64
Ohne Zusammenfassung 相似文献
92.
Castricum HL Sah A Kreiter R Blank DH Vente JF ten Elshof JE 《Chemical communications (Cambridge, England)》2008,(9):1103-1105
Unprecedented hydrothermal stability in functional membranes has been obtained with hybrid organic-inorganic nanoporous materials, enabling long-term application in energy-efficient molecular separation, including dehydration up to at least 150 degrees C. 相似文献
93.
Stump B Eberle C Kaiser M Brun R Krauth-Siegel RL Diederich F 《Organic & biomolecular chemistry》2008,6(21):3935-3947
Trypanothione reductase (TR) is an essential enzyme of trypanosomatids and therefore a promising target for the development of new drugs against African sleeping sickness and Chagas' disease. Diaryl sulfides with a central anilino moiety, decorated with a flexible N-alkyl side chain bearing a terminal ammonium ion, are a known class of inhibitors. Using computer modelling, we revised the binding model for this class of TR inhibitors predicting simultaneous interactions of the ammonium ion-terminated N-alkyl chain with Glu18 as well as Glu465'/Glu466' of the second subunit of the homodimer, whereas the hydrophobic substituent of the aniline ring occupies the "mepacrine binding site" near Trp21 and Met113. Systematic alteration of the carboxylate-binding fragments and the diaryl sulfide core of the inhibitor scaffold provided evidence for the proposed binding mode. In vitro studies showed IC(50) values in the low micromolar to submicromolar range against Trypanosoma brucei rhodesiense as well as the malaria parasite Plasmodium falciparum. 相似文献
94.
Olson MT Blank PS Sackett DL Yergey AL 《Journal of the American Society for Mass Spectrometry》2008,19(3):367-374
We present a data processing approach based on the spectral dot product for evaluating spectral similarity and reproducibility. The method introduces 95% confidence intervals on the spectral dot product to evaluate the strength of spectral correlation; it is the only calculation described to date that accounts for both the non-normal sampling distribution of the dot product and the number of peaks the spectra have in common. These measures of spectral similarity allow for the recursive generation of a consensus spectrum, which incorporates the most consistent features from statistically similar replicate spectra. Taking the spectral dot product and 95% confidence intervals between consensus spectra from different samples yields the similarity between these samples. Applying the data analysis scheme to replicates of brain tubulin CNBr peptides enables a robust comparison of tubulin isotype expression and post-translational modification patterns in rat and cow brains. 相似文献
95.
Prager L Dierdorf A Liebe H Naumov S Stojanović S Heller R Wennrich L Buchmeiser MR 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(30):8522-8529
The photochemical conversion of 200-500 nm layers of perhydropolysilazane --(SiH2-NH)n-- (PHPS) in the presence of oxygen into an SiOx network was studied. Different UV sources in the wavelength range of 160-240 nm, that is, 172 nm Xe2* and 222 nm KrCl* excimer, and 185 nm Hg low-pressure (HgLP) lamps were used for these purposes. The role of both ozone and O(1D) as well as of catalytic amounts of tertiary amines in the degradation process of PHPS and the formation of SiOx were studied. In this context, the kinetics of the entire reaction were elucidated and allowed both a continuous and discontinuous process to be established for the production of fully transparent, flexible barrier coatings. Barrier improvement factors (BIFs) of 400 were achieved with one single layer on 23 microm poly(ethyleneterephthalate) (PET), which translated into oxygen transmission rates (OTRs) of 0.20 cm3 m(-2) day(-1) bar(-1). Double layers prepared by this technique allowed the realization of OTRs of or=800. 相似文献
96.
Blank B Colling-Hendelkens M Kollann C Radacki K Rais D Uttinger K Whittell GR Braunschweig H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(17):4770-4781
Transition-metal-borylene complexes of the type [(OC)(5)M=BR] {M=Cr, Mo, W; R=N(SiMe(3))(2), 1a-3a, Si(SiMe(3))(3), 4a} and [(OC)(4)Fe=B=N(SiMe(3))(2)] (8) were prepared by salt elimination reactions. Synthesis of the latter complex was accompanied by the formation of substantial amounts of an unusual dinuclear iron complex [Fe(2){mu-C(2)O(2)(BN(SiMe(3))(2))}(2)(CO)(6)] (9). The aminoborylene complexes of Group 6 metals were converted to trans-[(Cy(3)P)(CO)(4)M=B=N(SiMe(3))(2)] (5a-7a) by irradiation in the presence of PCy(3). Structural and spectroscopic parameters were discussed with respect to the trans-effect of the borylene ligand and the degree of M-B d(pi)-p(pi)-backbonding. Computational studies were performed on Group 6-borylene complexes. The population and topological analyses as well as the molecular orbital composition are consistent with the presence of both sigma-and pi-type interactions. There are, however, indications that the d(pi)-p(pi)-backbonding in the silylborylene complex is significantly more pronounced than in the aminoborylene complexes. 相似文献
97.
An important problem of the monitoring of the environment is control of natural and waste waters. To elaborate the X-ray fluorescence determination of arsenic,selenium and mercury in the waters we used the extraction concentration of diethyldithiocarbamate of the elements from a strong acid solution. 相似文献
98.
Phenols of natural and antropogenic derivations are respected to the dangerous and wide occurring organical impurities coining in the environment with waste waters of chemical plants. Maximum permissible concentration (MPC) of phenol for unchlorinated water is 0.1 mg/l, and for chlorinated one - 0.001-0.002 mg/l. For the determination of such small contents of phenol in waters preliminary extractional or sorptional concentration is used. 相似文献
99.
S. N. Coppersmith Robert D. Blank Leo P. Kadanoff 《Journal of statistical physics》1999,97(3-4):429-457
We investigate a population genetics model introduced by Waxman and Peck(1) incorporating mutation, selection, and pleiotropy (one gene affecting several unrelated traits). The population is infinite, and continuous variation of genotype is allowed. Nonetheless, Waxman and Peck showed that if each gene affects three or more traits, then the steady-state solution of the model can have a nonzero fraction of the population with identical alleles. We use a recursion technique to calculate the distribution of alleles at finite times as well as in the infinite-time limit. We map Waxman and Peck's model into the mean-field theory for Bose condensation, and a variant of the model onto a bound-state problem in quantum theory. These mappings aid in delineating the region of parameter space in which the unique genotype occurs. We also discuss our attempts to correlate the statistics of DNA-sequence variation with the degree of pleiotropy of various genes. 相似文献
100.
Sasidhar Maddula Lars Mathias Blank Andreas Schmid Jörg Ingo Baumbach 《Analytical and bioanalytical chemistry》2009,394(3):791-800
Detection and immediate quantification of microbial metabolic activities is of high interest in fields as diverse as biotechnology
and infection biology. Interestingly, the most direct signals of microbial metabolism, the evolution of volatile metabolites,
is largely ignored in the literature, and rather, metabolite concentrations in the microbial surrounding or even disruptive
methods for intracellular metabolite measurements (i.e., metabolome analysis) are favored. Here, the development of a multi
capillary column coupled ion mobility spectrometer (MCC-IMS) was described for the detection of volatile organic compounds
from microbes and the MCC-IMS was used for characterization of metabolic activity of growing Escherichia coli. The MCC-IMS chromatogram of the microbial culture off-gas of the acetone-producing E. coli strain BL21 pLB4 revealed four analytes that positively correlated with growth, which were identified as ethanol, propanone
(acetone), heptan-2-one, and nonan-2-one. The occurrence of these analytes was cross-validated by solid-phase micro-extraction
coupled with gas chromatography mass spectrometry analysis. With this information in hand, the dynamic relationship between
the E. coli biomass concentration and the metabolite concentrations in the headspace was measured. The results suggest that the metabolic
pathways of heptan-2-one and nonan-2-one synthesis are regulated independent of each other. It is shown that the MCC-IMS in-line
off-gas analysis is a simple method for real-time detection of microbial metabolic activity and discussed its potential for
application in metabolic engineering, bioprocess control, and health care. 相似文献