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151.
Hypochlorite‐Mediated Modulation of Photoinduced Electron Transfer in a Phenothiazine–Boron dipyrromethene Electron Donor–Acceptor Dyad: A Highly Water Soluble “Turn‐On” Fluorescent Probe for Hypochlorite 下载免费PDF全文
Disha Soni Naresh Duvva Deepak Badgurjar Dr. Tapta Kanchan Roy Dr. Surendra Nimesh Geeta Arya Dr. Lingamallu Giribabu Dr. Raghu Chitta 《化学:亚洲杂志》2018,13(12):1594-1608
A highly water‐soluble phenothiazine (PTZ)–boron dipyrromethene (BODIPY)‐based electron donor–acceptor dyad ( WS‐Probe ), which contains BODIPY as the signaling antennae and PTZ as the OCl? reactive group, was designed and used as a fluorescent chemosensor for the detection of OCl?. Upon addition of incremental amounts of NaOCl, the quenched fluorescence of WS‐Probe was enhanced drastically, which indicated the inhibition of reductive photoinduced electron transfer (PET) from PTZ to 1BODIPY*; the detection limit was calculated to be 26.7 nm . Selectivity studies with various reactive oxygen species, cations, and anions revealed that WS‐Probe was able to detect OCl? selectively. Steady‐state fluorescence studies performed at varied pH suggested that WS‐Probe can detect NaOCl and exhibits maximum fluorescence in the pH range of 7 to 8, similar to physiological conditions. ESI‐MS analysis and 1H NMR spectroscopy titrations showed the formation of sulfoxide as the major oxidized product upon addition of hypochlorite. More interestingly, when WS‐Probe was treated with real water samples, the fluorescence response was clearly visible with tap water and disinfectant, which indicated the presence of OCl? in these samples. The in vitro cell viability assay performed with human embryonic kidney 293 (HEK 293) cells suggested that WS‐probe is non‐toxic up to 10 μm and implicates the use of the probe for biological applications. 相似文献
152.
Kiran A. Thabaj Deepak S. Munavalli Shivamurti A. Chimatadar Sharanappa T. Nandibewoor 《Transition Metal Chemistry》2007,32(7):902-912
The micro amounts of iodide (10−7) (mol dm−3) and chloride (10−2) (mol dm−3) mediated oxidation of antimony(III) by cerium(IV) in an aqueous sulphuric acid medium have been studied spectrophotometrically
at 25 °C and μ = 3.10 mol dm−3. The stoichiometry is 1:2 in chloride and iodide mediated reactions. i.e. one mole of antimony(III) requires two moles of cerium(IV). In the case of chloride mediated reaction, the reaction was
first order in cerium(IV) and halide concentrations, whereas in the case of iodide mediated reaction the order with respect
to [cerium(IV)] was unity and with respect to iodide concentrations was more than unity (ca. 1.4). In both chloride and iodide mediated reactions the order with respect to antimony(III) concentrations was less than
unity. Increase in sulphuric acid concentration increased the rate. The order with respect to H+ ion concentration was less than unity. Added products, cerium(III) and antimony(V) did not have any significant effect on
the reaction rate. The active species of oxidant was understood to be
, whereas that of reductant as SbCl3 in the case of chloride and SbI2+ in case of iodide mediated reactions. The possible reaction mechanisms were proposed and the activation parameters were determined
and discussed. 相似文献
153.
Reaction of a lithium boryl, [(THF)2Li{B(DAB)}] (DAB=[(DipNCH)2]2?, Dip=2,6‐diisopropylphenyl), with a dinuclear magnesium(I) compound [{(MesNacnac)Mg}2] (MesNacnac=[HC(MeCNMes)2]?, Mes=mesityl) unexpectedly afforded a rare example of a terminal magnesium boryl species, [(MesNacnac)(THF)Mg{B(DAB)}]. Attempts to prepare the magnesium boryl via a salt metathesis reaction between the lithium boryl and a β‐diketiminato magnesium iodide compound, instead led to an intractable mixture of products. Similarly, reaction of the lithium boryl with a β‐diketiminato beryllium bromide precursor, [(DepNacnac)BeBr] (Dep=2,6‐diethylphenyl) did not give a beryllium boryl, but instead afforded an unprecedented example of a beryllium substituted diazaborole heterocycle, [{(DepNacnac)Be(4‐DAB?H)}BBr]. For sake of comparison, the same group 2 halide precursor compounds were treated with a potassium gallyl analogue of the lithium boryl, viz. [(tmeda)K{:Ga(DAB)}] (tmeda=N,N,N’,N’‐tetramethylethylenediamine), but no reactions were observed. 相似文献
154.
Priyanka G.Mandhane Ratnadeep S.Joshi Deepak R.Nagargoje Charansingh H.Gill 《中国化学快报》2011,22(5):563-566
An efficient synthesis of novelα-aminophosphonates by the reaction of aldehydes and amines with triethyl phosphite in the presence of the easily available,inexpensive,and nontoxic catalyst thiamine hydrochloride(VB1).This method affords theα-aminopho-sphonates under the influence of ultrasound irradiation in aqueous medium,in short reaction times(4-6 min),high yields(85-95%), with improved purity.The process is green,mild,inexpensive and excellent yields are the main compensation of this procedure. 相似文献
155.
Ruchi Badoni Deepak Kumar Semwal Prabhakar P.Badoni Sudhir Kumar Kothiyal Usha Rawat 《中国化学快报》2011,22(1):81-84
A novel bacteriohopanoid elucidated as 3β-hydroxy-35-(cyclohexyl-5’-propan-7’-one)-33-ethyl-34-methyl-bactereohopane(1) has been isolated from the bark of Celtis australis(Ulmaceae) together with three known compounds apigenin,quercetin and its glucoside.The structure of 1 was characterized by means of chemical and spectral methods including advanced 2D NMR studies. 相似文献
156.
O Nikel D Laurencin C Bonhomme GE Sroga S Besdo A Lorenz D Vashishth 《The journal of physical chemistry. C, Nanomaterials and interfaces》2012,116(10):6320-6331
Age-related bone fragility fractures present a significant problem for public health. Measures of bone quality are increasingly recognized to complement the conventional bone mineral density (BMD) based assessment of fracture risk. The ability to probe and understand bone quality at the molecular level is desirable in order to unravel how the structure of organic matrix and its association with mineral contribute to the overall mechanical properties. The (13)C{(31)P} REDOR MAS NMR (Rotational Echo Double Resonance Magic Angle Spinning Nuclear Magnetic Resonance) technique is uniquely suited for the study of the structure of the organic-mineral interface in bone. For the first time, we have applied it successfully to analyze the structure of intact (non-powdered) human cortical bone samples, from young healthy and old osteoporotic donors. Loading problems associated with the rapid rotation of intact bone were solved using a Finite Element Analysis (FEA) approach, and a method allowing osteoporotic samples to be balanced and spun reproducibly is described. REDOR NMR parameters were set to allow insight into the arrangement of the amino acids at the mineral interface to be accessed, and SVD (Singular Value Decomposition) was applied to enhance the signal to noise ratio and enable a better analysis of the data. From the REDOR data, it was found that carbon atoms belonging to citrate/glucosaminoglycans (GAGs) are closest to the mineral surface regardless of age or site. In contrast, the arrangement of the collagen backbone at the interface varied with site and age. The relative proximity of two of the main amino acids in bone matrix proteins, hydroxyproline and alanine, with respect to the mineral phase was analyzed in more detail, and discussed in view of glycation measurements which were carried out on the tissues. Overall, this work shows that the (13)C{(31)P} REDOR NMR approach could be used as a complementary technique to assess a novel aspect of bone quality, the organic-mineral interface structure. 相似文献
157.
In this report, the crystal structure of a new polymorphic form of 2-(4-Methylbenzamido)-5-(4-fluoro-3-phenoxyphenyl)-1,3,4-thiadiazole have been investigated and compared with the previously reported form. Crystallization experiments from a non-polar solvent resulted in the formation of a newly obtained polymorph of this substituted 1,3,4 thiadiazole compound. Structural differences and similarities in both the polymorphic forms were explored in terms of supramolecular building blocks present in the crystal packing and their influences on the supramolecular construct are investigated in terms of the nature and energetics of the associated interactions. In addition, Hirshfeld surface analysis and calculations on the enrichment ratio were carried out for both the forms to isolate the various types of interatomic contacts and differentiate their contribution towards the molecular assembly, as obtained from 2D fingerprint plots. Also, the interaction energies were computed for the new polymorph and compared with the reported form. The studies render quantitative insights into the role of strong H-bonds and weak intermolecular interactions acting cooperatively in the crystal. In addition, the role of both electrostatic and dispersion energies contributes to the overall stability in the crystal packing. 相似文献
158.
Thomas Lainer Dr. Deepak Dange Michael Pillinger Prof. Dr. Roland C. Fischer Prof. Dr. Anne-Marie Kelterer Prof. Dr. Cameron Jones Dr. Michael Haas 《ChemistryOpen》2022,11(3):e202100240
A convenient metal-free approach towards an N-heterocyclic carbene (NHC)-coordinated disilene 2 is described. Compound 2 , featuring the disilene incorporated in cyclopolysilane framework, was obtained in good yield and characterized using NMR spectroscopy and X-ray crystallography. Density functional theory (DFT) calculations of the reaction mechanism provide a rationale for the observed reactivity and give detailed information on the bonding situation of the base-stabilized disilene. Compound 2 undergoes thermal or light- induced (λ=456 nm) NHC loss, and a dimerization process to give a corresponding dimer with a Si10 skeleton. In order to shed light on the dimerization mechanism, DFT calculations were performed. Moreover, the reactivity of 2 was examined with selected examples of transition metal carbonyl compounds. 相似文献
159.
An efficient copper-catalyzed method for the synthesis of biologically important ebselen and related analogues containing a Se-N bond has been developed. This is the first report of a catalytic process of selenation and Se-N bond formation reaction. Copper-catalyzed reaction tolerates functional groups such as amides, hydroxyls, ethers, nitro, fluorides, and chlorides. The best results are obtained by using a combination of potassium carbonate as a base, iodo- or bromo-arylamide substrates, selenium powder, and copper iodide catalyst. 相似文献
160.
N. K. Deepak 《Pramana》2010,74(3):421-440
The channelling and scattering yields of 1 MeV α-particles in the 〈100〉, 〈110〉 and 〈111〉 directions of silicon implanted with bismuth and ytterbium have been simulated using
N-body model. The close encounter yield from dopant atoms in silicon is determined from the flux density, using the Bontemps
and Fontenille method. All previous works reported in literature so far have been done with computer programmes using a statistical
analytical expression or by a binary collision model or a continuum model. These results at the best gave only the transverse
displacement of the lattice site from the concerned channelling direction. Here we applied the superior N-body model to study the yield from bismuth in silicon. The finding that bismuth atom occupies a position close to the silicon
substitutional site is new. The transverse displacement of the suggested lattice site from the channelling direction is consistent
with the experimental results. The above model is also applied to determine the location of ytterbium in silicon. The present
values show good agreement with the experimental results. 相似文献