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111.
Liubov
M. Lifshits John A. Roque III Prathyusha Konda Susan Monro Houston D. Cole David von Dohlen Susy Kim Gagan Deep Randolph P. Thummel Colin G. Cameron Shashi Gujar Sherri A. McFarland 《Chemical science》2020,11(43):11740
Mounting evidence over the past 20 years suggests that photodynamic therapy (PDT), an anticancer modality known mostly as a local treatment, has the capacity to invoke a systemic antitumor immune response, leading to protection against tumor recurrence. For aggressive cancers such as melanoma, where chemotherapy and radiotherapy are ineffective, immunomodulating PDT as an adjuvant to surgery is of interest. Towards the development of specialized photosensitizers (PSs) for treating pigmented melanomas, nine new near-infrared (NIR) absorbing PSs based on a Ru(ii) tris-heteroleptic scaffold [Ru(NNN)(NN)(L)]Cln, were explored. Compounds 2, 6, and 9 exhibited high potency toward melanoma cells, with visible EC50 values as low as 0.292–0.602 μM and PIs as high as 156–360. Single-micromolar phototoxicity was obtained with NIR-light (733 nm) with PIs up to 71. The common feature of these lead NIR PSs was an accessible low-energy triplet intraligand (3IL) excited state for high singlet oxygen (1O2) quantum yields (69–93%), which was only possible when the photosensitizing 3IL states were lower in energy than the lowest triplet metal-to-ligand charge transfer (3MLCT) excited states that typically govern Ru(ii) polypyridyl photophysics. PDT treatment with 2 elicited a pro-inflammatory response alongside immunogenic cell death in mouse B16F10 melanoma cells and proved safe for in vivo administration (maximum tolerated dose = 50 mg kg−1). Female and male mice vaccinated with B16F10 cells that were PDT-treated with 2 and challenged with live B16F10 cells exhibited 80 and 55% protection from tumor growth, respectively, leading to significantly improved survival and excellent hazard ratios of ≤0.2.Ru(ii) photosensitizers (PSs) destroy aggressive melanoma cells, triggering an immune response that leads to protection against tumor challenge and mouse survival. 相似文献
112.
A new sesquiterpene diol, now named jaeschkeanadiol, has been isolated from the roots of Ferula jaeschkeana Vatke and is shown to possess structure1. Its stereochemistry has been established by a direct chemical correlation with laserol (9). 相似文献
113.
An efficient new procedure for the degradation of cyclolaudenyl acetate to 3β - acetoxy - 4,4,14α -trimethyl - 9, 19 - cyclo - 5α - pregnan - 20 - one and/or 3β - acetoxy - 4,4,14α - trimethyl - 9,19 - cyclo - 5α -androstan - 17 - one is described. The key-step is simultaneous base-catalysed dehydrohalogenation and isomerisation of the resulting olefin, of a suitably derived halide. 相似文献
114.
115.
116.
A detailed theoretical study of the low-temperature lattice specific heat of Ni-based dilute alloys has been carried out.
Lattice Green’s function method has been used to calculate the local density of states of substitutional impurities and lattice
specific heat in different alloys. The resonance condition has been investigated for possible occurrence of resonance modes.
Except in NiCr and NiMn, low-frequency resonance modes have been obtained in all the alloys. However, no localized mode was
obtained. The impurity-induced increase in lattice specific heat is explained on the basis of the obtained resonance modes.
The calculation shows an excellent agreement with the measured lattice specific heat in these alloys 相似文献
117.
Mihir K. Chaudhurp Shiv K. Chettri Gagan C. Mandal Pradip C. Paul Satya B. Paul Pendyala Srinivas 《Journal of Chemical Sciences》1995,107(4):305-316
An interpretative account of the results of reactions in aqueous medium of a highly peroxygenated vanadium(V) complex, K [V(O2
3]·3H2O, with different organic and inorganic substrates is presented. The reactions were monitored by solution EPR spectroscopy
and isolation of products at different stages of the reactions. Redox reactions between diperoxide, K[VO(O2)2(H2O)] and VOSO4 were conducted. The results of the investigation suggest that secondary oxygen exchange-reaction occurs which not only depends
on but also utilises the intermediates in the primary reaction during diperoxovanadate-dependent oxidation of VOSO4.
In an interesting reactiontris(acetylacetonato)-manganese(III), Mn(acac)3, on being reacted with a hydrogen peroxide adduct, KF·H2O2, and bpy and phen afforded crystalline [Mn(acac)2(bpy)] and [Mn(acac)2(phen)], respectively. The X-ray structural analysis of [Mn(acac)2(phen)] showed that the compound crystallised in orthorhombic space groupPbcn. The structure consists of a pseudooctahedral Mn(II) ion being bound to two acac−(C5H5O
2
−
) and a phen ligand with the molecule lying on two-fold axis.
Reactivity profiles of two new chromium(VI) reagents viz., pyridinium fluorochromate, C5H5NH[CrO3F] (PFC), and quinolinium fluorochromate C9H7NH [CrO3F] (QFC), have been presented. The compounds are capable of acting as both electron-transfer and oxygen-atom-transfer agents.
The X-ray analysis of PFC crystals reveals that the compound crystallises in the orthorhombic space group CmcZ1. The structure consists of discrete pyridinium cations and CrO3 F anions with no significant hydrogen bonding. This results in total disorder of the pyridinium cation. The tetrahedral [CrO3 F]− ion lies on a crystallographic mirror plane. 相似文献
118.
Growth behavior of thin Ag films on Si substrates at room temperature has been investigated by scanning tunneling microscopy and reflection high energy electron diffraction. In the layer-plus-island growth Ag islands show strongly preferred atomic scale heights and flat top. At low coverage (1 ML), islands containing two atomic layers of Ag are overwhelmingly formed. At higher coverages island height distribution shows strong peaks at relative heights corresponding to an even number (2, 4, 6, …) of Ag atomic layers. Beyond some coverage the height preference vanishes due to the appearance of screw dislocations and spiral growth. 相似文献
119.
Sukh Dev 《Tetrahedron》1960,8(3-4):171-180
The structure, previously assigned to zerumbone, has been found to be untenable. The ketone has been shown to be monocyclic containing three ethylenic linkages, and has been further correlated with humulene. Results from ozonolysis, and base-catalysed cleavage allowed the compound to be formulated as 2,6,9,9-tetramethyl-2,6,10-cyclo-undecatrien-1-one. 相似文献
120.
We calculate geometric and homotopical bordism rings associated to semi-free S1 actions on complex manifolds, giving explicit generators for the geometric theory. The classification of semi-free actions with isolated fixed points up to cobordism complements similar results from symplectic geometry. 相似文献