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991.
Hernández-Chávez JF González-Córdova AF Rodríguez-Ramírez R Vallejo-Cordoba B 《Analytica chimica acta》2011,708(1-2):149-154
A polymerase chain reaction and capillary gel electrophoresis (PCR-CGE) method with ultraviolet (UV) or laser induced fluorescence detection (LIF) was established for the detection of chicken or turkey in heat-treated pork meat mixtures. Mitochondrial DNA samples extracted from heat treated meat were amplified with their corresponding specific primers yielding PCR products between 200 and 300 bp. LIF detection was superior than UV detection in terms of precision and sensitivity for the study of DNA fragments. The CGE-LIF method was highly reproducible and accurate for determining DNA fragment size. The PCR-CGE-LIF was sensitive since a significant fluorescent signal was obtained at the minimum admixture level employed of 1% in meat mixtures. Thus, the PCR-CGE-LIF method established was useful for the detection of chicken or turkey in heat treated meat mixtures and may prove to be useful for the detection of poultry meat in pork processed products. 相似文献
992.
Hernán Pessoa‐Mahana R. Acevedo Ramiro Araya‐Maturana Claudio Saitz C. David Pessoa‐Mahana 《合成通讯》2013,43(20):3559-3567
New benzothiophene arylpiperazine derivatives 8 (a–f) were synthesized as potential serotoninergic agents with 5‐HT1A receptor affinity. Preparation of the derivatives was performed by treating N‐[2‐(chloromethyl)phenyl]‐4,7‐dimethoxybenzo[b]thiophene‐2‐carboxamide (7) with a series of substituted 4‐arylpiperazines. 相似文献
993.
Fernando Sánchez‐Juanes María Carmen Muñiz César Raposo Silvia Rodríguez‐Prieto Alberto Paradela Yaremi Quiros Francisco López‐Hernández Laura Ferreira 《Electrophoresis》2013,34(17):2473-2483
Urine is a suitable biological fluid to look for markers of physiological and pathological processes, including renal and nonrenal diseases. In addition, it is an optimal body sample for diagnosis, because it is easily obtained without invasive procedures and can be sampled in large quantities at almost any time. Rats are frequently used as a model to study human diseases, and rat urine has been analyzed to search for disease biomarkers. The normal human urinary proteome has been studied extensively, but the normal rat urinary proteome has not been studied in such depth. In light of this, we were prompted to analyze the normal rat urinary proteome using three complementary proteomics platforms: SDS‐PAGE separation, followed by LC‐ESI‐MS/MS; 2DE, followed by MALDI‐TOF‐TOF and 2D‐liquid chromatography‐chromatofocusing, followed by LC‐ESI‐Q‐TOF. A total of 366 unique proteins were identified, of which only 5.2% of unique proteins were identified jointly by the three proteomics platforms used. This suggests that simultaneous proteomics techniques provide complementary and nonredundant information. Our analysis affords the most extensive rat urinary protein database currently available and this may be useful in the study of renal physiology and in the search for biomarkers related to renal and nonrenal diseases. 相似文献
994.
J. Chandradass Hern Kim Francis W. Y. Momade 《Journal of Sol-Gel Science and Technology》2013,65(2):189-194
In the present study, MgFe2O4 nanofibers with smaller diameter have been successfully fabricated via electrospinning utilizing sol–gel precursor. The single phase of spinel ferrite was obtained at 700 °C. Different PVP concentrations were used and the results show that PVP concentration had played important role in the formation, uniformity, homogeneity and particularly in the reduction of nanofibers diameter. The average diameter of the nanofibers prepared with PVP concentration (6.3, 7.6, and 8.9 wt%) and calcined at 700 °C were 70 ± 7.6, 86 ± 11 and 113 ± 13 nm respectively. 相似文献
995.
José Manuel Guevara‐Vela Rodrigo Chávez‐Calvillo Prof. Dr. Marco García‐Revilla Prof. Dr. Jesús Hernández‐Trujillo Prof. Dr. Ove Christiansen Prof. Dr. Evelio Francisco Prof. Dr. Ángel Martín Pendás Prof. Dr. Tomás Rocha‐Rinza 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(42):14304-14315
The cooperative effects of hydrogen bonding in small water clusters (H2O)n (n=3–6) have been studied by using the partition of the electronic energy in accordance with the interacting quantum atoms (IQA) approach. The IQA energy splitting is complemented by a topological analysis of the electron density (ρ( r )) compliant with the quantum theory of atoms‐in‐molecules (QTAIM) and the calculation of electrostatic interactions by using one‐ and two‐electron integrals, thereby avoiding convergence issues inherent to a multipolar expansion. The results show that the cooperative effects of hydrogen bonding in small water clusters arise from a compromise between: 1) the deformation energy (i.e., the energy necessary to modify the electron density and the configuration of the nuclei of the isolated water molecules to those within the water clusters), and 2) the interaction energy (Eint) of these contorted molecules in (H2O)n. Whereas the magnitude of both deformation and interaction energies is enhanced as water molecules are added to the system, the augmentation of the latter becomes dominant when the size of the cluster is increased. In addition, the electrostatic, classic, and exchange components of Eint for a pair of water molecules in the cluster (H2O)n?1 become more attractive when a new H2O unit is incorporated to generate the system (H2O)n with the last‐mentioned contribution being consistently the most important part of Eint throughout the hydrogen bonds under consideration. This is opposed to the traditional view, which regards hydrogen bonding in water as an electrostatically driven interaction. Overall, the trends of the delocalization indices, δ(Ω,Ω′), the QTAIM atomic charges, the topology of ρ( r ), and the IQA results altogether show how polarization, charge transfer, electrostatics, and covalency contribute to the cooperative effects of hydrogen bonding in small water clusters. It is our hope that the analysis presented in this paper could offer insight into the different intra‐ and intermolecular interactions present in hydrogen‐bonded systems. 相似文献
996.
Juan Olguín Adrián Castillo Virginia Gómez-Vidales Simón Hernández-Ortega Rubén A. Toscano Eduardo Muñoz 《Supramolecular chemistry》2013,25(6):502-509
The reactions of mono-, bis- and tetrapicolyl-p-tert-butylcalix[4]arene derivatives functionalised in the phenolic positions (L 1 –L 4 ) with copper(II) acetate resulted in the formation of discrete complexes or extended coordination polymers. The centrosymmetric dimer [Cu2(μ-O2CCH3)4(L 1 )2] 1, obtained with monodentate L 1 , has square pyramidal coordination around the copper centres and a cone conformer of monopicolyl-calix[4]arene acting as an axial ligand, with a molecule of acetonitrile hosted within its cavity. The potentially bidentate L 2 acts as a monodentate ligand, affording the complex [Cu2(μ-O2CCH3)4(L 2 )2] 2, which based on spectroscopic and combustion analysis data has a similar coordination sphere around Cu(II). Compound L 3 bridges two dicopper units in the coordination polymer [Cu2(μ-O2CCH3)4(μ-L 3 )] n 3, with the calixarene hosting a molecule of tetrahydrofuran. Finally, compound L 4 reacts with 4 equivalents of copper(II) acetate, presumably generating a two-dimensional coordination polymer formulated as [{Cu2(μ-O2CCH3)4}2(L 4 )] 4. 相似文献
997.
Víctor Agmo Hernández 《Journal of Solid State Electrochemistry》2013,17(2):299-305
This short review describes how the theory of electrochemical metal nucleation considering non-stationary effects due to the activation of latent nucleation sites has been successfully translated and applied to describe phenomena observed on lipid membranes. This rather unexpected connection is merely formal, but has resulted in a completely new approach in liposome research. It has been proposed that hydrophobic active sites spontaneously and constantly appear and disappear on lipid membranes. These sites control the affinity of liposomes for hydrophobic surfaces and determine the permeability of the lipid membrane to small hydrophilic molecules. Thus, the kinetic models for liposome adhesion on hydrophobic substrates and for the spontaneous leakage of liposomal content are identical to that of non-stationary nucleation mentioned above. Therefore, the broad scope of the available work on metal nucleation has facilitated the interpretation of the data obtained in liposome research. Future applications of the nucleation model in the realm of liposomes are also discussed. 相似文献
998.
Dr. Cristina M. Posadas Dr. Nuria Rendón Dr. Joaquín López‐Serrano Dr. Yohar A. Hernández Dr. Eleuterio Álvarez Prof. Dr. Margarita Paneque Prof. Dr. Manuel L. Poveda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(5):1796-1809
The bis(ethylene) IrI complex [TpIr(C2H4)2] ( 1 ; Tp=hydrotris(3,5‐dimethylpyrazolyl)borate) reacts with two equivalents of aromatic or aliphatic aldehydes in the presence of one equivalent of dimethyl acetylenedicarboxylate (DMAD) with ultimate formation of hydride iridafurans of the formula [TpIr(H){C(R1)?C(R2)C(R3)O }] (R1=R2=CO2Me; R3=alkyl, aryl; 3 ). Several intermediates have been observed in the course of the reaction. It is proposed that the key step of metallacycle formation is a C? C coupling process in the undetected IrI species [TpIr{η1‐O‐R3C(?O)H}(DMAD)] ( A ) to give the trigonal‐bipyramidal 16 e? IrIII intermediates [TpIr{C(CO2Me)?C(CO2Me)C(R3)(H)O }] ( C ), which have been trapped by NCMe to afford the adducts 11 (R3=Ar). If a second aldehyde acts as the trapping reagent for these species, this ligand acts as a shuttle in transfering a hydrogen atom from the γ‐ to the α‐carbon atom of the iridacycle through the formation of an alkoxide group. Methyl propiolate (MP) can be used instead of DMAD to regioselectively afford the related iridafurans. These reactions have also been studied by DFT calculations. 相似文献
999.
A robust, specific, precise and sensitive high-performance liquid chromatographic method has been described for purity control of temocillin. Chromatographic separation was achieved using a Symmetry C18 (150 × 4.6 mm, 5 µm) column kept at 30 °C. The mobile phase consisted of a gradient mixture of mobile phases A (5 g/L solution of Na2HPO4·2H2O, pH 7) and B (ACN-MeOH-H2O, 50:10:40 v/v/v) pumped at a flow rate of 1.0 mL/min. UV detection was performed at 235 nm. The developed method was validated according to the ICH guidelines for its robustness, selectivity, sensitivity, precision and linearity. An experimental design was applied for the robustness study. Linearity was assessed both at impurity level in the range from LOQ to 10 % and assay level from 25 % to 150 % (0.6 mg/mL = 100 %). It is the first liquid chromatographic method described for the separation of temocillin and its potential impurities. It was possible to identify four degradation products from the forced degradation studies. The degradants do not interfere with the main peak and other known impurities showing that the method is specific and stability-indicating. 相似文献
1000.
O. Félix-Beltrán M. Gómez-Bock E. Hernández A. Mondragón M. Mondragón 《International Journal of Theoretical Physics》2011,50(7):2291-2303
We study the singularity of the surface that represents the masses of the isolated doublet of heavy, neutral Higgs bosons,
H
2–H
3, in a toy model based on the MSSM with CP violation, in parameter space. These two heavy, neutral Higgs bosons are coherent
and, for large values of the masses, nearly degenerate. In this scenario, mixing between the mass eigenstates of the H
2–H
3 system could be very large and exact degeneracy is possible. As function of the Lagrangian parameters, the physical mass
of the doublet has an algebraic branch point of rank one at the exceptional point where the two masses are equal. The real
and imaginary parts of the masses in the doublet have branch cuts that start at the same branch point but extend in opposite
directions in parameter space. Associated with this branch point, the propagator of the mixing doublet of neutral heavy Higgs
bosons has a double pole in the complex s-plane of the energy squared. We computed the mass surface of the isolated doublet of H
2–H
3 bosons as function of the Lagrangian parameters in the neighbourhood of the exceptional point in a toy model of the system
H
2–H
3. We also computed the trajectories of the poles of the transition matrix for values of the Lagrangian parameters close to
the exceptional point and explained the characteristic change of identity seen in these trajectories in the s-plane as a manifestation of the topology of the two-sheeted mass surfaces in the space of Lagrangian parameters. 相似文献