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81.
Jindong Ren Marvin Cnudde Dana Brünink Stefan Buss Constantin G. Daniliuc Lacheng Liu Harald Fuchs Cristian A. Strassert Hong‐Ying Gao Nikos L. Doltsinis 《Angewandte Chemie (International ed. in English)》2019,58(43):15396-15400
A series of Pt(II) complexes with tetradentate luminophores has been designed, synthesized, and deposited on coinage metal surfaces with the aim to produce highly planar self‐assembled monolayers. Low‐temperature scanning tunneling microscopy (STM) and density functional theory (DFT) calculations reveal a significant initial nonplanarity for all complexes. A subsequent metal‐catalyzed separation of the nonplanar moiety at the bridging unit via the scission of a C?N bond is observed, leaving behind a largely planar core complex. The activation barrier of this bond scission process is found to depend strongly on the chemical nature of both bridging group and coordination plane, and to increase from Cu(111) through Ag(111) to Au(111). 相似文献
82.
Nikos I. Karachalios 《Letters in Mathematical Physics》2008,83(2):189-199
We consider on a bounded domain \(\Omega \subset {\mathbb{R}}^N\) , the Schrödinger operator ? Δ ? V supplemented with Dirichlet boundary solutions. The potential V is either the critical inverse square potential V(x) = (N ? 2)2/4|x|?2 or the critical borderline potential V(x) = (1/4)dist(x, ?Ω)?2. We present explicit asymptotic estimates on the eigenvalues of the critical Schrödinger operator in each case, based on recent results on improved Hardy–Sobolev type inequalities. 相似文献
83.
Yogesh Patil George Zapsas Yves Gnanou Nikos Hadjichristidis 《Journal of polymer science. Part A, Polymer chemistry》2020,58(1):163-171
This study presents the synthesis and properties of linear PVDF-based amphiphilic triblock terpolymers with PS and PEO, [PVDF-b-PS-b-PEO], by adopting a procedure that involves: (a) iodine-transfer polymerization (ITP) of VDF with 1-iodoperfluorohexane (C6F13I) serving as chain-transfer agent (CTA) to afford C6F13-PVDF-I, (b) ITP of styrene with the C6F13-PVDF-I macromolecular-CTA to obtain C6F13-PVDF-b-PS-I diblock copolymer, (c) end-group exchange from iodo- to azido-group by nucleophilic substitution reaction with NaN3, and (d) copper-catalyzed azide-alkyne cycloaddition (CuAAC) with alkyne-terminated PEO to achieve C6F13-PVDF-b-PS-b-PEO triblock terpolymers. The 1H and 19F NMR spectroscopy confirmed the presence of all blocks, while gel permeation chromatography traces showed the living nature of ITP technique. The self-assembly of these terpolymers was investigated in films (atomic force microscopy and DSC), as well as in aqueous and organic solvents (DLS). The analysis of crystalline phases based on the FTIR spectroscopy indicated the conversion of PVDF α-phase into α + β-phases and β + γ-phases upon the incorporation of PS and PEO blocks, respectively. The synthesized amphiphilic copolymers were evaluated (fluorescence spectroscopy) as carriers of small hydrophobic molecules in water. © 2019 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 163–171 相似文献
84.
Ionics - Films consisting of phosphorus-doped multi-walled carbon nanotubes (further denoted as P-MWCNTs) were fabricated by means of chemical vapor deposition technique with decomposition of... 相似文献
85.
86.
Viko Ladelta George Zapsas Yves Gnanou Nikos Hadjichristidis 《Journal of polymer science. Part A, Polymer chemistry》2019,57(24):2450-2456
New tricrystalline triblock terpolymers, polyethylene‐block‐poly(ε‐caprolactone)‐block‐poly(L‐lactide) (PE‐b‐PCL‐b‐PLLA), were synthesized by ROP of ε‐caprolactone (CL) and L‐lactide (LLA) from linear ω‐hydroxyl polyethylene (PE‐OH) macroinitiators. The linear PE‐OH macroinitiators were prepared by C1 polymerization of methylsulfoxonium methylide (polyhomologation). Tin(II) 2‐ethylhexanoate was used as the catalyst for the sequential ROP of CL and LLA in one‐pot polymerization at 85 °C in toluene (PE‐OH macroinitiators are soluble in toluene at 80 °C). 1H NMR spectra confirmed the formation of PE‐b‐PCL‐b‐PLLA triblock terpolymers through the appearance of the characteristic proton peaks of each block. GPC traces showed the increase in the number average molecular weight from PE‐OH macroinitiator to PE‐b‐PCL, and PE‐b‐PCL‐b‐PLLA corroborating the successful synthesis. The existence of three crystalline blocks was proved by DSC and XRD spectroscopy. © 2019 The Authors. Journal of Polymer Science Part A: Polymer Chemistry published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2450–2456 相似文献
87.
88.
The present technique describes the development of a simple sensitive spot optical test and the construction of a portable biosensor for the rapid one-shot detection of naphthalene acetic acid (NAA) using stabilized lipid films supported on a methacrylate polymer on a glass fiber filter with incorporated auxin-binding protein 1 receptor. The lipid films without the receptor provided fluorescence under a UV lamp. The use of the receptor in these films quenched this fluorescence and the colour became similar to that of the filters without the lipid films. A drop of aqueous solution of naphthalene acetic acid provided a “switching on” of the fluorescence which allows the rapid detection of this stimulant at the levels of 10−9 M concentrations. It was also possible to have quantitative data based on a calibration graph. The effect of potent interferences included a wide range of compounds. The results showed no interferences from these compounds in concentration levels usually found in real samples. The method was applied for the determination of NAA in fruits and vegetables and the reproducibility of the method was checked in about 50 samples. A quantitative method for the detection of NAA in crops that can be complimentary to HPLC methods is provided in the present paper. These lipid films can be used as portable biosensors for the rapid one-shot detection of NAA in fruits and vegetables by non-skilled personnel in the field. 相似文献
89.
Catherine P. Raptopoulou Athanassios K. Boudalis Katerina N. Lazarou Vassilis Psycharis Nikos Panopoulos Michael Fardis George Diamantopoulos Jean-Pierre Tuchagues Alain Mari George Papavassiliou 《Polyhedron》2008,27(18):3575-3586
The use of salicylaldehyde oxime (H2salox) in manganese(III) carboxylate chemistry has yielded new members of the family of hexanuclear compounds presenting the [Mn6(μ3-O)2(μ2-OR)2]12+ core, complexes [MnIII6(μ3-O)2(O2CPh)2(salox)6(L1)2(L2)2] (L1 = py, L2 = H2O (1); L1 = Me2CO, L2 = H2O (2); L1 = L2 = MeOH (3)). Addition of NaOMe to the acetonitrile reaction mixture, afforded the 1D complex [MnIII3Na(μ3-O)(O2CPh)2(salox)3(MeCN)]n (4), whereas addition of NaClO4 to the acetone reaction mixture afforded an analogous 1D complex [MnIII3Na(μ3-O)(O2CPh)2(salox)3(Me2CO)]n (5). The structures of 1–3 present the [Mn6(μ3-O)2(μ2-OR)2]12+ core and can be described as two [Mn3(μ3-O)]7+ triangular subunits linked by two μ2-oximato oxygen atoms of the salox2− ligands, which show the less common μ3-κ2O:κO′:κN coordination mode. The benzoato ligands are coordinated through the usual syn,syn-μ2-κO:κO′ mode. The 1D polymeric structures of 4 and 5 consist of alternating [Mn3(μ3-O)]7+ subunits and Na+ atoms linked through two μ3-κ2O:κO′:κN and one μ4-κ2O:κ2O′:κN salox2− ligands as well as one syn,anti-μ2-κO:κO′ benzoato ligand. DC and AC magnetic susceptibility studies on 1 revealed the stabilization of an S = 4 ground state, and indications of single-molecule magnetism behavior, whereas the DC experimental data from polycrystalline sample of 5 are indicative of antiferromagnetic interactions within the [Mn3] subunit. Solid state 1H NMR data of 1 were used to probe the spin-lattice relaxation of the system. 相似文献
90.
Bakandritsos A Psarras GC Boukos N 《Langmuir : the ACS journal of surfaces and colloids》2008,24(20):11489-11496
The preparation of magnetic iron oxide colloids directly from the coprecipitation of Fe (2+) and Fe (3+) species at different temperatures may lead to crystallites of higher size as the temperature of the reaction increases. On the other hand, dynamic light scattering investigations and dielectric measurements rather point to the similar colloidal size of the entities existing in their aqueous or solid-state dispersions, irrespective of the size of the primary nanocrystallites. Significant enhancement of the stability of the colloids, even in the presence of high electrolyte concentrations, is furnished after the addition of relatively small amounts of poly(vinyl alcohol), and the stabilization mechanism is discussed in terms of the various forces participating in the system. The experimental results suggest that the increased colloidal stability is triggered from the particles' decrease of velocity rather than from steric (entropic) effects originating from polymer absorption. 相似文献