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1.
We study the effect of numerical integration when the p-version of the finite element method is used to approximate the eigenpairs of elliptic partial differential operators. We obtain optimal orders of convergence for approximate eigenvalues and eigenvectors under a certain set of requirements on the quadrature rules employed. This is the same set of conditions that has been shown (in an earlier work) to be sufficient for the optimal approximation of the solutions of the corresponding source problems. 相似文献
2.
Yahya S. Alqahtani Sunil S. More Keerthana R. Ibrahim Ahmed Shaikh Anusha K. J. Veena S. More Francois N. Niyonzima Uday M. Muddapur Aejaz A. Khan 《Molecules (Basel, Switzerland)》2022,27(13)
Enzymes that degrade pectin are called pectinases. Pectinases of microbial origin are used in juice clarification as the process is cost-effective. This study screened a pectinase-producing bacterium isolated from soil and identified as Bacillus subtilis 15A B-92 based on the 16S rRNA molecular technique. The purified pectinase from the isolate showed 99.6 U/mg specific activity and 11.6-fold purity. The molecular weight of the purified bacterial pectinase was 14.41 ± 1 kD. Optimum pectinase activity was found at pH 4.5 and 50 °C, and the enzyme was 100% stable for 3.5 h in these conditions. No enzymatic inhibition or activation effect was seen with Fe2+, Ca2+, or Mg2+. However, a slight inhibition was seen with Cu2+, Mn2+, and Zn2+. Tween 20 and 80 slightly inhibited the pectinase, whereas iodoacetic acid (IAA), ethylenediaminetetraacetate (EDTA), urea, and sodium dodecyl sulfate (SDS) showed potent inhibition. The bacterial pectinase degraded citrus pectin (100%); however, it was inactive in the presence of galactose. With citrus pectin as the substrate, the Km and Vmax were calculated as 1.72 mg/mL and 1609 U/g, respectively. The high affinity of pectinase for its substrate makes the process cost-effective when utilized in food industries. The obtained pectinase was able to clarify orange and apple juices, justifying its application in the food industry. 相似文献
3.
Kaushik Pal Uday Narayan Maiti Tapas Pal Majumder Subhas Chandra Debnath 《Applied Surface Science》2011,258(1):163-168
A series of novel wurtzite cadmium sulphide (CdS) nanowires with uniform diameter were synthesized by using a rapid and simple solvothermal route. CdS nano structures with certain morphology could be selectively produced by only varying the concentration of poly ethylene glycol (PEG) as a surfactant in the reaction system with cadmium acetate, sulphur powder and ethelynediamine (EDA). We extensively studied UV-vis absorption spectra, photoluminescence spectra after confirming CdS nanowires with diameter 24-25 nm and length ranging up to several nano meters by field emission scanning electron microscopy (FE-SEM). Therefore we may definitely propose a new formation mechanism of CdS nanowires assisted by PEG with its illustrating optical properties. 相似文献
4.
Estrogen induced proliferation of existing mutant cells is widely understood to be the major risk determining factor in the
development of breast cancer. Hence determination of the Estrogen Receptor[ER] status is of paramount importance. We have
carried out the synthesis and characterization of a novel NIR fluorescent dye conjugate aimed at measuring ER+ve status in-vivo.
The conjugate was synthesized by ester formation between 17-β estradiol and a cyanine dye namely: bis-1, 1-(4-sulfobutyl)
indotricarbocyanine-5-carboxylic acid, sodium salt. The replacement of the sodium ion in the ester by a larger glucosammonium
ion was found to enhance the hydrophilicity and reduce the toxic effect on cell lines. The excitation and emission peaks for
the dye were recorded as 750 and 788 nm respectively; ideal for non-invasive optical imaging owing to minimal tissue attenuation
and auto-fluorescence at these wavelengths. The dye (NIRDC1) has a significant drop in plasma-protein binding therefore leading to marked improvement in pharmacokinetic profile such
as dye evacuation in comparison to ICG. In addition the dye showed enhanced fluorescence quantum yield, molar extinction coefficient
and linearity in fluorescence relative to ICG. This dye can be potentially used as a target specific exogenous contrast agent
in molecular optical imaging for early detection of breast cancer. 相似文献
5.
Rhodamine-19 (Rh-19) incorporated three types of sol–gel samples (mentioned as dope route-I, dope route-II and dip method) were prepared by using two different methods of dye impregnation. The photophysical properties of all the three types of Rh-19 incorporated sol–gel solids were studied by using the UV–Visible absorption and the fluorescence spectroscopy. A single photon counting technique was used to estimate the lifetime of fluorescent species. From the study of fluorescence spectra, the coexistence of dimers (fluorescent and non-fluorescent both) and monomer of Rh-19 was observed. The photophysical properties of Rh-19 were found to be the best in dip sample, medium in dope route-II sample and low in dope route-I sample. After studying photophysical properties, the samples were subjected to laser study under nitrogen laser pumping at 337.1 nm at the rate of 1.5 Hz in transverse dye laser cavity. The highest laser efficiency and photostability of the dye were observed in dip sample, medium in dope route-II sample and small in dope route-I sample. A comparison between photophysical properties and laser performance of these materials showed a very good correlation. 相似文献
6.
Baishya B Prabhu UR Suryaprakash N 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2008,192(1):101-111
In general, the proton NMR spectra of chiral molecules aligned in the chiral liquid crystalline media are broad and featureless. The analyses of such intricate NMR spectra and their routine use for spectral discrimination of R and S optical enantiomers are hindered. A method is developed in the present study which involves spin state selective two dimensional correlation of higher quantum coherence to its single quantum coherence of a chemically isolated group of coupled protons. This enables the spin state selective detection of proton single quantum transitions based on the spin states of the passive nuclei. The technique provides the relative signs and magnitudes of the couplings by overcoming the problems of enantiomer discrimination, spectral complexity and poor resolution, permitting the complete analyses of the otherwise broad and featureless spectra. A non-selective 180 degrees pulse in the middle of MQ dimension retains all the remote passive couplings. This accompanied by spin selective MQ-SQ conversion leads to spin state selective coherence transfer. The removal of field inhomogeneity contributes to dramatically enhanced resolution. The difference in the cumulative additive values of chemical shift anisotropies and the passive couplings, between the enantiomers, achieved by detecting Nth quantum coherence of N magnetically equivalent spins provides enhanced separation of enantiomer peaks. The developed methodology has been demonstrated on four different chiral molecules with varied number of interacting spins, each having a chiral centre. 相似文献
7.
8.
Pawar Umakant D. Pawar Chandrakant D. Mavle Rajendra R. Pardeshi Rajendra K. 《平面色谱法杂志一现代薄层色谱法》2019,32(5):435-437
JPC – Journal of Planar Chromatography – Modern TLC - A novel chromogenic reagent was developed for the identification and detection of organophosphorus herbicide. The organophosphorus... 相似文献
9.
Supriya S. Khot Prashant V. Anbhule Uday V. Desai Prakash P. Wadgaonkar 《Comptes Rendus Chimie》2018,21(9):814-821
Tris-hydroxymethylaminomethane has been demonstrated to be an efficient organocatalyst in diversity-oriented synthesis of medicinally prevalent spirochromenes by one-pot, three-component reactions between isatins, malononitrile, and enolizable CH acids like dimedone, 4-hydroxycoumarin, 4-hydroxy-N-methylquinolin-2-one, or in situ generated 2-methylpyrazolon-2-one. Biodegradability and extremely low cost of the catalyst are the noteworthy features of this chromatography-free protocol. 相似文献
10.