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1.
We obtain a solution of the DGLAP equation for the gluon at low x first by expanding the gluon in a Taylor series and then using the method of characteristics. We test its validity by comparing
it with that of Glück, Reya and Vogt. The convergence criteria of the approximation used are also discussed. We also calculate
εF
2(x,Q)2/ε In Q
2 using its approximate relations with the gluon distribution at low x. The predictions are then compared with the HERA data. 相似文献
2.
Algebras and Representation Theory - We introduce the concept of a prime band in a string algebra Λ and use it to associate to Λ its finite bridge quiver. Then we introduce a new... 相似文献
3.
Papia Datta Dibakar Sardar Uttam Panda Ajanta Halder Nabin Baran Manik Chun‐Jung Chen Chittaranjan Sinha 《应用有机金属化学》2016,30(5):323-334
Os(II) hydridocarbonyl complexes of coumarinyl azoimidazoles, [Osh(CO)(PPh3)2(CZ‐4R‐R′)]0/+ ( 3 , 4 ) (CZ‐R‐H = 2‐(coumarinyl‐6‐azo)‐4‐substituted imidazole or 1‐alkyl‐2‐(coumarinyl‐6‐azo)‐4‐substituted imidazole), were characterized from spectroscopic data and the single‐crystal X‐ray data for one of the complexes, [Osh(CO)(PPh3)2(CZ‐4‐Ph)] ( 3c ) (CZ‐4‐Ph = 2‐(coumarinyl‐6‐azo)‐4‐phenylimidazolate), confirmed the structure. The complexes show higher emission (quantum yield ? = 0.0163–0.16) and longer lifetime (τ = 1.4–10.3 ns) than free ligands (? = 0.0012–0.0185 and τ = 0.685–1.306 ns). Cyclic voltammetry shows quasi‐reversible metal oxidation at 0.67–0.94 V for [Os(III)/Os(II)] and 1.21–1.36 V for [Os(IV)/Os(III)] and subsequent azo reductions (?0.68 to ?0.95 V for [? N?N? ]/[? N N? ]? and irreversible < ?1.2 V for [? N N? ]?/[? N? N? ]2?) of the chelated coumarinyl azoimidazole. The complexes are photostable and show better photovoltaic power conversion efficiency than free ligands. Also, the complexes were used as catalysts for the oxidation of primary/secondary alcohols to aldehydes/ketones using oxidizing agents like N‐methylmorpholine N‐oxide, t‐BuOOH and H2O2. Density functional theory computation was carried out from the optimized structures and the data obtained were used to interpret the electronic and photovoltaic properties. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
4.
Humaira Latif Sadaf Jamil Rana Babar Shahzad Khan Sardar Sikandar Hayat 《辐射效应与固体损伤》2017,172(11-12):851-865
Trace rare gas optical emission spectroscopy (TRG-OES) is carried out to determine the excitation temperature, vibrational temperature, dissociation fraction and nitrogen (N) atom density in 50?Hz active screen cage nitrogen plasma, as a function of discharge parameters (current density and fill pressure) and hydrogen concentrations. The excitation temperature is determined from Ar–I emission lines and is found to increase with hydrogen mixing. In a similar fashion, the vibrational temperature of second positive system is determined and found to have increasing trend with hydrogen addition. The dissociation fraction increases with hydrogen concentration up to 40% H2 in the nitrogen plasma, so as the nitrogen atom density. 相似文献
5.
Andrew L. Hector William Levason Mark E. Light Gillian Reid Kripasindhu Sardar Wenjian Zhang 《无机化学与普通化学杂志》2013,639(6):906-910
Crystalline CrOCl3 contains [Cl2OCr(μ‐Cl)2CrOCl2] molecules with two square pyramidal CrOCl4 units sharing a common edge and with the Cr–O arranged anti, a new structure type for transition metal MOX3 compounds. Crystals are monoclinic with space group P21/c, Z = 4, with a = 5.735(5), b = 13.738(7), c = 11.318(4) Å, α = 90°, β = 98.346(6)°, γ = 90°. Its IR and UV/Vis spectra are reported and compared with those of the C3v monomer found in the gas phase. Structures are also reported for M2[CrOCl5] (M = Cs or Rb) and show a pseudo‐octahedral anion. Cs2[CrOCl5] adopts a K2PtCl6‐type structure with [CrOCl5]2– ions randomly orientated, but Rb2[CrOCl5] is orthorhombic with space group Pnma with a = 13.6471(7), b = 9.9175(5), and c = 6.9562(4) Å. Rietveld refinement of the data on the rubidium salt gave Cr–O = 1.628(1), Cr–CltransO = 2.652(7), Cr–CltransCl = 2.239(8)–2.342(3) Å. Corresponding CrV oxide bromide species do not form. 相似文献
6.
U. V. Valiev J. B. Gruber D. K. Sardar B. Zandi I. S. Kachur A. K. Mukhammadiev V. G. Piryatinskaya V. Yu. Sokolov I. S. Edelman 《Physics of the Solid State》2007,49(1):91-98
The Zeeman effect in the 7 F 6 → 5 D 4 absorption band of the Tb3+ ion in the paramagnetic garnets Tb3Ga5O12 and Tb3Al5O12 was studied. The field dependences of the Zeeman splitting of some absorption lines are found to exhibit unusual behavior: as the magnetic field increases, the band splitting decreases rather than increases. Symmetry analysis relates these lines to 4f → 4f electron transitions of the doublet-quasi-doublet or quasi-doublet-doublet type, for which the field dependences of the splitting differ radically from the well-known field dependences of the Zeeman splitting for quasi-doublet-quasi-doublet or quasi-doublet-singlet transitions in a longitudinal magnetic field. 相似文献
7.
In this paper we introduce the notion of operator semirings of a -semiring to study -semirings. It is shown that the lattices of all left (right) ideals (two-sided ideals) of a -semiring and its right (respectively left) operator semiring are isomorphic. This has many applications to characterize various -semirings.AMS Subject Classification (2000): 16Y60, 16Y99 相似文献
8.
Overtone spectrum of o, m and p-nitrobenzaldehydes and p-chlorobenzaldehyde has been studied in 2000–12000 cm−1 region. Vibrational frequencies and anharmonicity constants for aryl as well as alkyl CH stretch vibrations have been determined.
We have also determined the internuclear distances for the aryl CH bond in the different molecules. The small variation observed
in these distances is an indication of the substitution effect.
It is observed that in the case of p-disubstituted benzens, the shift in aryl CH bond is proportional to sum of the Hammet σ of the substituents. However in the
case of o-disubstituted benzenes it is only 80% of the para-substituted shift. 相似文献
9.
Federico Gonzalez‐Fernandez Brandi Betts‐Obregon Brian Yust Joshua Mimun Dongjin Sung Dhiraj Sardar Andrew T. Tsin 《Photochemistry and photobiology》2015,91(2):371-378
Retinol degrades rapidly in light into a variety of photoproducts. It is remarkable that visual cycle retinoids can evade photodegradation as they are exchanged between the photoreceptors, retinal pigment epithelium and Müller glia. Within the interphotoreceptor matrix, all‐trans retinol, 11‐cis retinol and retinal are bound by interphotoreceptor retinoid‐binding protein (IRBP). Apart from its role in retinoid trafficking and targeting, could IRBP have a photoprotective function? HPLC was used to evaluate the ability of IRBP to protect all‐trans and 11‐cis retinols from photodegradation when exposed to incandescent light (0 to 8842 μW cm?2); time periods of 0–60 min, and bIRBP: retinol molar ratios of 1:1 to 1:5. bIRBP afforded a significant prevention of both all‐trans and 11‐cis retinol to rapid photodegradation. The effect was significant over the entire light intensity range tested, and extended to the bIRBP: retinol ratio 1:5. In view of the continual exposure of the retina to light, and the high oxidative stress in the outer retina, our results suggest IRBP may have an important protective role in the visual cycle by reducing photodegradation of all‐trans and 11‐cis retinols. This role of IRBP is particularly relevant in the high flux conditions of the cone visual cycle. 相似文献
10.
The reactions of Vaska’s complex [IrCl(CO)(PPh3)2] with 2-(coumaryl-6-azo)imidazole (CZ-H) and its derivatives (CZ-X) have synthesized [Ir(CZ)(CO)(PPh3)2] and [Ir(CZ-X)(CO)(PPh3)2]. All the complexes have been characterized by FT-IR, UV-Vis, 1H NMR and FAB-MS spectroscopy. The structural confirmation has been done in one case, by a single crystal X-ray diffraction study, which shows a distorted square pyramidal geometry around the central Ir atom. The complexes are emissive at room temperature. The cyclic voltammetry of the complexes shows a metal centered irreversible oxidation and ligand centered quasireversible reduction couples. To get an insight into the electronic structure, absorption spectra and electrochemical properties, detailed calculations on all three complexes have been performed at the DFT level. 相似文献