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The magnetic dipole interaction of the 91 keV state of147Pm in an environment of metallic neodymium has been investigated by a time-differential perturbed angular correlation (TDPAC) experiment. The measurement was performed in an external magnetic field of 2.94 (3) T at room temperature. From the Larmor precession frequency the magnetic dipole moment of the 91 keV state is derived as =+3.22(16) K. The enhancement of the external magnetic field by the paramagnetic 4f shell determines the ionicity of the Pm ion as Pm3+ in metallic and as Pm4+ in non-metallic sources.  相似文献   
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The IPAC-method has been used with the external magnetic field of 9.0 T of a split coil superconducting magnet and with the internal field of PdFe for a measurement of magnetic moments of105Pd states populated in the decay of 41.29d105Ag. The results are:μ 7/2 (645 keV)=?1.49(9) nmμ 5/2 (319 keV)=+0.95(20) nmμ 3/2 (280keV)=?0.074(13) nm. The half-life of the 645 keV state has been redetermined by use of cooled thallium free Nal detectors asT 1/2 (645 keV)=126(2) ps. γ-γ directional correlations were measured with a system of three large Ge planar diodes for the cascades 443–645 keV, 332–319 keV, 393–280 keV, and 64–280 keV and analyzed in terms of dipole quadrupole mixing ratios of theγ-lines involved. The spin of the 673 keV state was derived as l/2+.  相似文献   
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The magnetic dipole interaction of the 57 keV state of143Pr in an environment of metallic cerium and in an aqueous solution of Ce(NO3)3 has been investigated by time-differential perturbed angular correlation experiments. The measurements were performed in external magnetic fields between 0.94 T and 2.24 T and at temperatures between 77 K and 1200 K. From the temperature dependence of the observed spin rotation the ionicity of the Pr ion is determined as Pr4+ in the Ce(NO3)3 and as Pr3+ in Ce metal in the intermediate nuclear state. The magnetic dipole moment of the 57 keV state is derived as = +(3.4±0.1)K. From the room temperature relaxation constants 2 = (0.19±0.03)109s–1 for Ce(NO3)3 and 2= (0.07±0.02)109s–1 for Ce metal the correlation times J = (3.8±0.7)10–13s and J = (1.4±0.4)10–13s respectively are deduced. The angular correlation coefficientA 2=+0.17±0.02 is in good agreement with the result of a decoupling experiment.  相似文献   
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We studied the water density profile close to spherical and planar hydrophobic objects using molecular dynamics (MD) simulations. For normal pressure and room temperature, the depletion layer thickness of a planar substrate is approximately 2.5 Angstroms. Even for quite large spherical solutes with a radius of R = 18 Angstroms, the depletion layer thickness is reduced by 30%, which shows that substrate curvature and roughness is an experimentally important factor. Rising temperature leads to a substantial increase of the depletion layer thickness. The compressibility of the depletion layer is found to be surprisingly small and only approximately 5 times higher than that of bulk water. A high electrostatic surface potential of 0.5 V is found, which presumably plays an important role in the presence of charged solutes, since it can promote adsorption into the interfacial layer.  相似文献   
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Plants are an important source of drug development and numerous plant derived molecules have been used in clinical practice for the ailment of various diseases. The Toll-like receptor-4 (TLR-4) signaling pathway plays a crucial role in inflammation including rheumatoid arthritis. The TLR-4 binds with pro-inflammatory ligands such as lipopolysaccharide (LPS) to induce the downstream signaling mechanism such as nuclear factor κappa B (NF-κB) and mitogen activated protein kinases (MAPKs). This signaling activation leads to the onset of various diseases including inflammation. In the present study, 22 natural compounds were studied against TLR-4/AP-1 signaling, which is implicated in the inflammatory process using a computational approach. These compounds belong to various classes such as methylxanthine, sesquiterpene lactone, alkaloid, flavone glycosides, lignan, phenolic acid, etc. The compounds exhibited different binding affinities with the TLR-4, JNK, NF-κB, and AP-1 protein due to the formation of multiple hydrophilic and hydrophobic interactions. With TLR-4, rutin had the highest binding energy (−10.4 kcal/mol), poncirin had the highest binding energy (−9.4 kcal/mol) with NF-κB and JNK (−9.5 kcal/mol), respectively, and icariin had the highest binding affinity (−9.1 kcal/mol) with the AP-1 protein. The root means square deviation (RMSD), root mean square fraction (RMSF), and radius of gyration (RoG) for 150 ns were calculated using molecular dynamic simulation (MD simulation) based on rutin’s greatest binding energy with TLR-4. The RMSD, RMSF, and RoG were all within acceptable limits in the MD simulation, and the complex remained stable for 150 ns. Furthermore, these compounds were assessed for the potential toxic effect on various organs such as the liver, heart, genotoxicity, and oral maximum toxic dose. Moreover, the blood–brain barrier permeability and intestinal absorption were also predicted using SwissADME software (Lausanne, Switzerland). These compounds exhibited promising physico-chemical as well as drug-likeness properties. Consequently, these selected compounds portray promising anti-inflammatory and drug-likeness properties.  相似文献   
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A forced degradation study of idebenone was conducted under conditions of UV irradiation, acid, basic and oxidative hydrolysis and in order to develop an isocratic stability-indicating LC-UV method for drug quantification in chitosan and N-carboxymethylchitosan nanoparticles obtained by spray drying. The drug was more labile to alkaline treatment than under the other forced degradation conditions. Idebenone and its degradation products were optimally resolved (resolution >4) on a Luna Phenomenex C18 column with mobile phase composed by methanol:water: (80:20% v/v) at a flow rate of 1.0 mL min?1, at 30 °C, using wavelength of 279 nm for drug detection. The method was linear, over a drug concentration range of 2 to 10 μg mL?1. The RSD% value of intra- and inter-day precision studies was <1.5. The method showed excellent recoveries (99.4 to 101.1%). The LOD and LOQ values were found to be 0.18 and 0.59 μg mL?1, respectively. In conclusion this method can be used as a rapid and accurate assay of idebenone in the nanoparticles during stability tests.  相似文献   
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