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91.
Physics of Atomic Nuclei - Neutrino oscillation is an experimentally established phenomenon by which neutrinos undergo flavor transformations periodically as they propagate large enough distances.... 相似文献
92.
A. Dhal R. K. Sinha P. Agarwal S. Kumar Monika B. B. Singh R. Kumar P. Bringel A. Neusser R. Kumar K. S. Golda R. P. Singh S. Muralithar N. Madhavan J. J. Das A. Shukla P. K. Raina K. S. Thind A. K. Sinha I. M. Govil P. K. Joshi R. K. Bhowmik A. K. Jain S. C. Pancholi L. Chaturvedi 《The European Physical Journal A - Hadrons and Nuclei》2006,27(1):33-36
High-spin states in 78Kr have been studied via the 63Cu (19F, 2p2n)78Kr reaction at a beam energy of 60 MeV using the Indian National Gamma Array (INGA). In this nucleus, lifetimes have been
measured upto the Iπ=22+ level in the yrast positive-parity band and upto the Iπ=15- level in the negative-parity band using the Doppler Shift Attenuation Method (DSAM). The deduced transition quadrupole moments
Qt's are found to decrease with rotational frequency for both the bands. 相似文献
93.
Ajit Chaturvedi N. D. Shukla Pramod S. Shukla 《Annals of the Institute of Statistical Mathematics》1992,44(1):157-167
The sequential procedure developed by Bhargava and Srivastava (1973, J. Roy. Statist. Soc. Ser. B, 35, 147–152) to construct fixed-width confidence intervals for contrasts in the means is further analyzed. Second-order approximations for the first two moments of the stopping time and the coverage probability associated with the sequential procedure, are obtained. A lower bound for the number of additional observations after stopping is derived, which ensures the mxact probability of coverage. Moreover, two-stage, three-stage and modified sequential procedures are proposed for the same estimation problem. Relative advantages and disadvantages of these sampling schemes are discussed and their properties are studied. 相似文献
94.
From Linear to Angular Isomers: Achieving Tunable Charge Transport in Single‐Crystal Indolocarbazoles Through Delicate Synergetic CH/NH⋅⋅⋅π Interactions 下载免费PDF全文
Dr. Hui Jiang Dr. Peng Hu Dr. Jun Ye Dr. Apoorva Chaturvedi Dr. Keke K. Zhang Yongxin Li Dr. Yi Long Prof. Denis Fichou Prof. Christian Kloc Prof. Wenping Hu 《Angewandte Chemie (International ed. in English)》2018,57(29):8875-8880
Weak intermolecular interaction in organic semiconducting molecular crystals plays an important role in molecular packing and electronic properties. Here, four five‐ring‐fused isomers were rationally designed and synthesized to investigate the isomeric influence of linear and angular shapes in affecting their molecular packing and resultant electronic properties. Single‐crystal field‐effect transistors showed mobility order of 5,7‐ICZ (3.61 cm2 V?1 s?1) >5,11‐ICZ (0.55 cm2 V?1 s?1) >11,12‐ICZ (ca. 10?5 cm2 V?1 s?1) and 5,12‐ICZ (ca. 10?6 cm2 V?1 s?1). Theoretical calculations based on density functional theory (DFT) and polaron transport model revealed that 5,7‐ICZ can reach higher mobilities than the others thanks to relatively higher hole transfer integral that links to stronger intermolecular interaction due to the presence of multiple NH???π and CH???π(py) interactions with energy close to common NH???N hydrogen bonds, as well as overall lower hole‐vibrational coupling owing to the absence of coupling of holes to low frequency modes due to better π conjugation. 相似文献
95.
96.
Partial Molar Volumes of Some of α-Amino Acids in Binary Aqueous Solutions of MgSO4·7H2O at 298.15 K
The apparent molar volume, V
o
φ, 2, of glycine, alanine, α-amino-n-butyric acid, valine and leucine have been determined in aqueous solutions of 0.25, 0.5 and 1.0 mol⋅dm−3 magnesium sulfate, and the partial specific volume from density measurements at 298.15 K. These data have been used to calculate the infinite dilution apparent molar volume, V
o
2,m
, group contribution of amino acids and partial molar volume of transfer, Δtr
V
2,m
o, from water to aqueous magnesium sulfate solutions. The linear correlation of V
2,m
o for a homologous series of amino acids has been utilized to calculate the contributions of charged end groups (NH3
+, COO−), CH2 - groups and other alkyl chains of amino acids to V
2,m
o. The results for Δtr
V
2,m
o of amino acids from water to aqueous magnesium sulfate solutions have been interpreted in terms of ion-ion, ion-polar, hydrophilic-hydrophilic and hydrophobic-hydrophobic group interactions. The values of the standard partial molar volume of transfer for the amino acids with different hydrophobic contents, from water to aqueous MgSO4 are in general positive, indicating the predominance of the interactions of zwitterionic/hydrophilic groups of amino acids with ions of the salt. The hydration number decreases with increasing concentration of salt. The number of water molecules hydrated to amino acids decreases, further strengthening the predominance of ionic/hydrophilic interactions in this system. 相似文献
97.
Summary. A novel process for the one-step chemoselective conversion of alkyl halides into carbamates as protected amines was developed
using benzyltrimethylammonium hydroxide (Triton-B) in presence of gaseous carbon dioxide. Thus, carbamate esters of different
amines were prepared in very good to excellent yields.
Present address: Institute of Organic and Biomolecular Chemistry, George–August University, 37077, G?ttingen, Germany 相似文献
98.
A new ligand, 1-(2-furanthiocarbo)-3-thiosemicarbazide (H2ftsc), prepared from thiosemicarbazide and carboxymethyl-2-furandithioate, forms complexes [Mn(ftsc)(H2O)2], [Pd(ftsc)] · 2H2O, [M(Hftsc)(acac)2] (M=CoIII or CrIII), [M(Hftsc)2(acac)] (M=MnIII or FeIII) and [Zn(Hftsc)2] · 2H2O, which were characterized by elemental analyses, magnetic susceptibility, i.r., electronic and n.m.r. spectral data. The Mössbauer spectra of [Fe(Hftsc)2(acac)] at 298K and 80K suggest the presence of high-spin iron(III) with an S=5/2 state. In vivo and in vitro antitumour activity of the ligand and the complexes have been screened towards several tumour cell-lines. 相似文献
99.
Harsh S. Shah Kaushalendra Chaturvedi Matthias Zeller Simon Bates Kenneth Morris 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(9):1213-1219
Phenytoin sodium, a salt of 5,5‐diphenylimidazolidine‐2,4‐dione, or phenytoin, is commercially available in various dosage forms for its anti‐epileptic properties to treat and prevent seizures. The title compound, poly[aquatris(μ3‐4,4‐diphenyl‐2,5‐dioxoimidazolidin‐1‐ido)trimethanoltrisodium(I)], [Na3(C15H11N2O2)3(CH4O)3(H2O)1.08]n, a methanol solvate and hydrate of phenytoin sodium, forms a modulated crystal structure that consists of a supercell made up of three close‐to‐identical repeat units. Each of the basic fragments consists of one phenytoin anion, a sodium cation, and either a methanol, or a methanol and a water molecule coordinated to the sodium ion, yielding a formula unit of Na(C15H11N2O2)(CH3OH)x(H2O)y for each of the three segments (x, y = 0 or 1; x + y = 1 or 2). Modulation along the b axis is introduced due to the presence or absence of water or methanol molecules at sodium and by the alternating torsion angles of one of the two phenytoin phenyl rings. Individual segments within the asymmetric unit are linked by covalent Na—O and Na—N bonds, with each sodium ion coordinated to one anionic amide N atom and three keto O atoms. The Na—N and one of the Na—O bonds connect (C15H11N2O2)·Na units along the modulation direction, creating an infinite [(C15H11N2O2)·Na] chain that is further stabilized by intramolecular N—H…O hydrogen bonding parallel to [010]. The second Na—O bond connects this chain with a symmetry‐equivalent copy of itself created by a screw‐axis operation, yielding double strands of [(C15H11N2O2)·Na] chains. Two of these double strands, propagating in opposite directions, constitute the content of the unit cell. Neighboring double strands are connected with each other to form layers perpendicular to the a axis, tethered together via O—H…O hydrogen bonds involving the water and methanol molecules. In addition to modulation, each of the repeat units also exhibits disorder of the modulated segments. Phenyl rings of each repeat unit are rotationally disordered, and sodium‐coordinated methanol and water molecules are also positionally disordered and/or partially occupied. The solvated structure reported here, while not matching the patterns reported for any of the known forms of phenytoin sodium, does provide a first insight into the complications and complexities involved in resolving the structure of anhydrous phenytoin sodium. 相似文献
100.