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171.
Multidrug‐Containing,Salt‐Based,Injectable Supramolecular Gels for Self‐Delivery,Cell Imaging and Other Materials Applications 下载免费PDF全文
Rajdip Roy Prof. Parthasarathi Dastidar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(42):14929-14939
Both molecular and crystal‐engineering approaches were exploited to synthesize a new class of multidrug‐containing supramolecular gelators. A well‐known nonsteroidal anti‐inflammatory drug, namely, indomethacin, was conjugated with six different l ‐amino acids to generate the corresponding peptides having free carboxylic acid functionality, which reacted further with an antiviral drug, namely, amantadine, a primary amine, in 1:1 ratio to yield six primary ammonium monocarboxylate salts. Half of the synthesized salts showed gelation ability that included hydrogelation, organogelation and ambidextrous gelation. The gels were characterized by table‐top and dynamic rheology and different microscopic techniques. Further insights into the gelation mechanism were obtained by temperature‐dependent 1H NMR spectroscopy, FTIR spectroscopy, photoluminescence and dynamic light scattering. Single‐crystal X‐ray diffraction studies on two gelator salts revealed the presence of 2D hydrogen‐bonded networks. One such ambidextrous gelator (capable of gelling both pure water and methyl salicylate, which are important solvents for biological applications) was promising in both mechanical (rheoreversible and injectable) and biological (self‐delivery) applications for future multidrug‐containing injectable delivery vehicles. 相似文献
172.
Chantry RL Siriwatcharapiboon W Horswell SL Logsdail AJ Johnston RL Li ZY 《The journal of physical chemistry. C, Nanomaterials and interfaces》2012,116(18):10312-10317
This study focuses on the deposition and growth mode of rhodium (Rh) on gold (Au) seed nanorods (NRs). Using a combination of scanning transmission electron microscopy imaging, energy-dispersive X-ray spectroscopy, and UV-visible absorption spectroscopy, we show that Rh deposition results in an uneven overlayer morphology on the Au NR seeds, with a tendency for Rh deposition to occur preferentially on the Au NR ends. The results suggest that complex and kinetically driven metal-metal interactions take place in this system. 相似文献
173.
The reaction of chloroacetyl chloride and triethylamine with a chiral imine derived from the combination of methyl glyoxylate and protected L-threonine gave two optically active α-amino acid derivatives with a cis-substituted β-lactam skeleton in a 72:28 ratio. The major product is obtained in 59% yield by simple crystallisation. 相似文献
174.
Metal recovery from low concentration solutions using a flow-by reactor under galvanostatic approach
A recently proposed method using constant current steps were applied for a period of time on a reticulated vitreous carbon cathode. The current steps were calculated from a theoretical analysis of the metal concentration profile assuming that the metal was deposited under mass transport control. A model was developed to predict the concentration decay of metal ions during the process. The current required to reduce the metal at the mass transfer limit at each time step was predicted from the concentration decay obtained from the model. This process should enable one to maintain high metal recovery rates whilst maximizing current efficiency. This concept was tested on Cu(II) deposition from an acidified sulfate electrolyte using a flowby reactor system with a reticulated vitreous carbon electrode. The model was good for predicting copper metal removal using a three dimensional cathode in dilute rinse waters. Also, the predicted current efficiency was in good agreement with that obtained using the experimental data. 相似文献
175.
Dipak Ghosh Madhumita Lahiri Argha Deb Susobhan Das Krishnadas Purkait Biswanath Biswas Jayanta Roy Choudhury Rini Chatterjee Abdul Kayum Jafry 《The European Physical Journal C - Particles and Fields》2011,71(1):243-249
The scaled factorial moments and the multifractal moments have been investigated in different??-intervals to study the dynamical fluctuation of pions produced in 200 AGeV32S-Ag/Br interaction. In order to investigate the detail characteristics of intermittency behaviour, theF-moments are extracted up to the eighth order of moments in differentM-intervals. The analysis indicates a non-thermal phase transition and different regime of particle production during the hadronisation process. 相似文献
176.
R. G. Stebbins T. Roy T. R. Doane 《International journal of environmental analytical chemistry》2013,93(3):127-137
Abstract The 1-ethylmonocarboxylic acid of Malathion (MCA) was identified as a metabolite of Malathion in the gut of golden shiners (N. Chrysoleucas) (7.11 × 102±0.66 × 102 ng/g tissue). As noted in the literature the rate of hydrolysis of Malathion above pH 7 is first order with respect to Malathion and pH dependent. In addition, the rate of hydrolysis of Malathion in aquaria housing these fish was found to be dependent on the concentration of Ca+2; sparging the aquaria with air affected the rate. Some of the hydrolysis products of Malathion were identified by gc/ms and found to be pH dependent above pH 7. The half-life of Malathion under different conditions, the identification of some hydrolytic products and a general scheme for the analysis of Malathion, along with some of its metabolic and hydrolytic products are included in this paper. 相似文献
177.
The infectious disease burden imposed by trypanosomatidae family continues to create burden in countries that are least equipped
to bring new medicines to the clinic. For sickness caused by this family of parasites (African trypanosomiasis, Chagas disease,
and leishmaniasis) no vaccines are available, and currently available drugs suffer from insufficient efficacy, excessive toxicity,
and steady loss of effectiveness due to resistance. Availability of the genome sequence of pathogens of this family offers
a unique avenue for the identification of novel common drug targets for all three pathogens. Sirtuin family of nicotinamide
adenine dinucleotide (NAD)-dependent deacetylases are remarkably conserved throughout evolution from archaebacteria to eukaryotes
and plays an important role in trypanosomatidae biology and virulence. In order to gain insight for selective drug design,
three-dimensional (3D) models of L. major, L. infantum, T. brucie, and T. cruzi sirtuin were constructed by homology modeling and compared with human sirtuin. The molecular electrostatic potentials and
cavity depth analysis of these models suggest that the inhibitor binding catalytic domain has various minor structural differences
in the active site of trypanosomal and human sirtuin, regardless of sequence similarity. These studies have implications for
designing effective strategies to identify inhibitors that can be developed as novel broad-spectrum antitrypanosomal drugs. 相似文献
178.
R. S. Stein M. Sethumadhavan R. A. Gaudiana T. Adams D. Guarrera S. K. Roy 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(7):517-531
Abstract At present we have strong evidence that several members of a series of wholly-aromatic, para-linked, rodlike polyamides, polyesters, and polyesteramides form molecular composites with certain flexible-chain, thermoplastic polymers over a wide range of compositions. This paper reports on the initial results of an investigation of intermolecular interactions using spectroscopy and various scattering techniques as well as characterization of some of the mechanical and optical properties of these materials. The composites are made by two techniques: 1) photo-polymerization of a homogeneous solution of a rodlike polymer in a monomer containing a photoinitiation; 2) solvent evaporation from homogeneous solutions of very limited combinations of solvent, rodlike polymers and flexible polymers. While both of these techniques produce optically clear, nonscattering films of various thicknesses over the entire compositional range, e.g., 1–99 wt% of rodlike polymer, the latter is generally more convenient and has been used extensively in this study. Optical and electron microscopy, wide angle light scattering, and spectroscopic and thermal analysis support the view that these polymer combinations are truly molecularly dispersed. 相似文献
179.
M. Roy S. Sahu S. K. Barbar S. Jangid 《Journal of Thermal Analysis and Calorimetry》2013,113(2):873-879
Polycrystalline ceramic samples of Bi4V2?xMexO11 (Me = Nb, Zr, Y and Cu and x = 0.0 and 0.02) have been synthesized by standard solid state reaction method using high purity oxides. The formation of the compounds have been analysed by X-ray diffraction method. The dielectric constant, dielectric loss and AC conductivity as a function of frequency and temperature have been measured. The dielectric studies indicate that the material is highly lossy and hence its AC conductivity increases with the increase of temperature. The DC conductivity of material has been measured as a function of temperature from room temperature to 380 °C and its activation energy was calculated using the relation σ = σ 0exp (?E a/kT). The modulated differential scanning calorimetry has been used to investigate the effect of substitution on the heat capacity and heat flow of the compounds. The results are discussed in detail. 相似文献
180.
Abhijit Chandra Roy V.S. Nisha Chetna Dhand Md. Azahar Ali B.D. Malhotra 《Analytica chimica acta》2013
We report results of the studies relating to the fabrication and characterization of a conducting polymer based molecularly imprinted para-nitrophenol (PNP) sensor. A water pollutant, para-nitrophenol is electrochemically imprinted with polyvinyl sulphonic acid (PVSA) doped polyaniline onto indium tin oxide (ITO) glass substrate. This PNP imprinted electrode (PNPI-PANI-PVSA/ITO) prepared via chronopotentiometric polymerization and over-oxidation is characterized by Fourier transform infra-red spectroscopy (FT-IR), UV–visible (UV–vis) spectroscopy, contact angle (CA), scanning electron microscopy (SEM), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) studies. The response studies of PNPI-PANI-PVSA/ITO electrode carried out using DPV reveal a lower detection limit of 1 × 10−3 mM, improved sensitivity as 1.5 × 10−3 A mM−1 and stability of 45 days. The PNPI-PANI-PVSA/ITO electrode shows good precision with relative standard deviation of 2.1% and good reproducibility with standard deviation of 3.78%. 相似文献