全文获取类型
收费全文 | 1048篇 |
免费 | 60篇 |
国内免费 | 5篇 |
专业分类
化学 | 873篇 |
晶体学 | 8篇 |
力学 | 13篇 |
数学 | 134篇 |
物理学 | 85篇 |
出版年
2023年 | 10篇 |
2022年 | 15篇 |
2021年 | 20篇 |
2020年 | 21篇 |
2019年 | 26篇 |
2018年 | 16篇 |
2017年 | 9篇 |
2016年 | 31篇 |
2015年 | 34篇 |
2014年 | 36篇 |
2013年 | 69篇 |
2012年 | 58篇 |
2011年 | 103篇 |
2010年 | 47篇 |
2009年 | 51篇 |
2008年 | 73篇 |
2007年 | 95篇 |
2006年 | 75篇 |
2005年 | 73篇 |
2004年 | 61篇 |
2003年 | 35篇 |
2002年 | 33篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 11篇 |
1997年 | 11篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1937年 | 1篇 |
1932年 | 2篇 |
1924年 | 2篇 |
1919年 | 1篇 |
1917年 | 1篇 |
排序方式: 共有1113条查询结果,搜索用时 156 毫秒
151.
Corrigendum: Multifunctional Nanoprobes for Nanoscale Chemical Imaging and Localized Chemical Delivery at Surfaces and Interfaces
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Yasufumi Takahashi Dr. Andrew I. Shevchuk Dr. Pavel Novak Prof. Yanjun Zhang Neil Ebejer Prof. Julie V. Macpherson Prof. Patrick R. Unwin Dr. Andrew J. Pollard Dr. Debdulal Roy Dr. Charles A. Clifford Dr. Hitoshi Shiku Prof. Tomokazu Matsue Prof. David Klenerman Prof. Yuri E. Korchev 《Angewandte Chemie (International ed. in English)》2014,53(28):7109-7109
152.
153.
Dr. Julie Martin Dr. Mohammad Wehbi Dr. Cécile Echalier Dr. Sylvie Hunger Dr. Audrey Bethry Prof. Xavier Garric Dr. Coline Pinese Prof. Jean Martinez Dr. Lubomir Vezenkov Prof. Gilles Subra Prof. Ahmad Mehdi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(56):12839-12845
A simple and efficient way to synthesize peptide-containing silicone materials is described. Silicone oils containing a chosen ratio of bioactive peptide sequences were prepared by acid-catalyzed copolymerization of dichlorodimethylsilane, hybrid dichloromethyl peptidosilane, and Si(vinyl)- or SiH-functionalized monomers. Functionalized silicone oils were first obtained and then, after hydrosilylation cross-linking, bioactive polydimethylsiloxane (PDMS)-based materials were straightforwardly obtained. The introduction of an antibacterial peptide yielded PDMS materials showing activity against Staphylococcus aureus. PDMS containing RGD ligands showed improved cell-adhesion properties. This generic method was fully compatible with the stability of peptides and thus opened the way to the synthesis of a wide range of biologically active silicones. 相似文献
154.
Deborah C. Bebout James F. Bush II Elizabeth M. Shumann Julie A. Viehweg Margaret E. Kastner Damon A. Parrish Steven M. Baldwin 《Journal of chemical crystallography》2003,33(5-6):457-463
The dimeric mercurous ion has been encapsulated by a pair of the tetradentate tripodal nitrogen ligands tris[(2-(6-methylpyridyl))methyl]amine (TLA). The complex [Hg2(TLA)2](ClO4)2 (1) was isolated directly from an acetonitrile solution of Hg(ClO4)2 3H2O and TLA. Complex 1 crystallizes in the triclinic space group
with a = 10.537(2) Å, b = 10.751(2) Å, c = 10.907(2) Å, = 75.20(3), = 73.73(3), = 75.73(3), and Z = 1. The cation is located an inversion center. The Hg–Hg and Hg–Namine bond distances are 2.5469(8) and 2.297(6) Å, respectively, and the average Hg–Npyridyl bond length is 2.75(7) Å. Complex 1 was stable indefinitely in acetonitrile-d
3 solution, permitting detection of 13 and 22 Hz heteronuclear couplings between the Hg(I) ions and the methylene protons of the ligand. Comparisons with the structures and spectroscopic properties of related mercuric and mercurous complexes are made. 相似文献
155.
During our studies toward the synthesis of the ABC ring system of hexacyclinic acid, we have observed a dramatic influence of the solvent on both our key steps. The diastereoselectivity of the intermolecular Michael addition could be totally reversed by changing the polarity of the solvent, and trifluoroethanol was found to be the optimal solvent for the following Mn(III)-promoted radical cyclization. 相似文献
156.
157.
Hasan K Fowler C Kwong P Crane AK Collins JL Kozak CM 《Dalton transactions (Cambridge, England : 2003)》2008,(22):2991-2998
The structures and properties of six new iron(iii) diamine-bis(phenolate) complexes are reported. Reaction of anhydrous FeX(3) salts (where X = Cl or Br) with the diprotonated tripodal tetradentate ligands 2-pyridylamino-N,N-bis(2-methylene-4-methyl-6-tert-butylphenol), H(2)[L(1)], and N,N-dimethyl-N',N'-bis(2-methylene-4-methyl-6-tert-butylphenol)ethylenediamine, H(2)[L(2)], produces the trigonal bipyramidal iron(iii) complexes, [L(1)]FeCl , [L(1)]FeBr , [L(2)]FeCl and [L(2)]FeBr . Reaction of FeX(3) with the related linear tetradentate ligand N,N'-bis(4,6-tert-butyl-2-methylphenol)-N,N'-bismethyl-1,2-diaminoethane, H(2)[L(3)], generates square pyramidal iron(iii) complexes, [L(3)]FeCl and [L(3)]FeBr . Complexes have been characterized using electronic absorption spectroscopy and magnetometry. Single crystal X-ray molecular structures have been determined for complexes 1, 3, 5 and 6. 相似文献
158.
Hygroscopic growth of multicomponent aerosol particles influenced by several cycles of relative humidity 总被引:1,自引:0,他引:1
Infrared aerosol flow tube experiments were performed for mixtures of ammonium, sulfate, and hydrogen ions at 293 K. The impact of the cycling of relative humidity (RH) on the crystals formed and on the hygroscopic growth was evaluated. Submicron particles having an extent of neutralization (X) between 0.60 and 0.75 were the focus, with special emphasis on the composition of aqueous letovicite (NH4)3H(SO4)2 (X = 0.75) because of its unique behavior. Aqueous letovicite particles crystallized initially as an external mixture of solid particles, forming pure particles of letovicite (NH4)3H(SO4)2(s) (LET) in some cases and internally mixed particles of ammonium sulfate ((NH4)2SO4(s);AS) and ammonium bisulfate (NH4HSO4(s); AHS) in other cases. Cycling between 3% and 48% RH increased the fraction of LET particles in the aerosol population, moving in the direction of the more thermodynamically favored species. However, some internally mixed particles remained even after multiple cycles, possibly indicative of a memory effect of AS as a heterogeneous nucleus for AHS. For all compositions studied, the RH of first water uptake and the magnitude of water uptake at higher RH were compared to model predictions. As expected, the more acidic particles (X = 0.60 and 0.65) took up water at the eutonic RH (37%) of mixed AHS/LET particles, but not as expected, both solids dissolved completely, arguing for an increased water solubility possibly attributable to nanocrystalline materials. Particles of X = 0.70 took up water above 41% RH, suggesting a particle morphology of an outer coating of AHS that prevents water uptake at the lower eutonic RH values of mixed AHS/LET and AHS/AS particles. Particles of X = 0.75 took up water as expected for an externally mixed particle population of LET and AS/AHS particles, although the fraction of each type in the population depended on the RH history. These results show that the hysteresis effect for some particles depends on a multi-node RH history. The implication for atmospheric particles is that the crystals present therein as well as particle morphology, water content, and extent of internal/external mixing might continue to evolve during multiple atmospheric cycles of RH. 相似文献
159.
Bottier C Géan J Desbat B Renault A Marion D Vié V 《Langmuir : the ACS journal of surfaces and colloids》2008,24(19):10901-10909
Puroindolines (PINs), basic and cysteine-rich proteins of wheat endosperm, are composed of two proteins, puroindoline-a (PIN-a) and puroindoline-b (PIN-b). Using a monolayer assay at the air/liquid interface, both PIN-a and PIN-b were studied in pure components and mixed with wheat galactolipids, 1,2-di-O-acyl-3-O-(beta-d-galactopyranosyl)- sn-glycerol (MGDG) and 2-di-O-acyl-3-O-(beta-d-galactopyranosyl-1,6-beta-d-galactopyranosyl)-sn-glycerol (DGDG). Following the adsorption of PINs at the air/liquid interface thanks to surface pressure increases, we concluded that PIN-a displays a more amphipathic character than PIN-b. Compression isotherms combined with ellipsometric measurements showed that the area per molecule is smaller and the protein film is more condensed for PIN-a than for PIN-b. According to the polarization modulation-infrared reflection-absorption spectroscopy data, both proteins display a highly alpha-helical structure and the alpha-helices are oriented rather parallel to the interface. By measuring the overpressure due to PIN adsorption into MGDG and DGDG monolayers, we observed that PIN-a interacts more strongly into lipid films than PIN-b. The observation by atomic force microscopy of mixed protein/lipid films showed that the nature of the lipid plays a significant role in the organization of PINs, particularly for PIN-a. The presence of galactolipids at the interface stabilizes the alpha-helical structure of PINs, but significant changes were observed concerning the orientation of the alpha-helices. They adopt a perfect parallel orientation to the interface in the MGDG monolayer, whereas the bundle of alpha-helices orients normal to the interface in the DGDG film. 相似文献
160.
Julie A. Horner George C.-Y. Chan Scott A. Lehn Gary M. Hieftje 《Spectrochimica Acta Part B: Atomic Spectroscopy》2008
Recent experiments involving aerosol introduction into the inductively coupled plasma have shown that intact droplets and solute particles cause enormous fluctuations in analyte emission and mass-spectral signals. Here, particle-vaporization kinetics are simulated as a detailed function of the operating conditions, fundamental properties and spatial location in the inductively coupled plasma, and as a function of several of the properties of the particles themselves: diameter, chemical composition and size distribution. These simulations portray the particle vaporization as proceeding nominally linearly with respect to the particle radius when the particles are small, but roughly quadratically with radius when the particles are very large. Further, the heat- and mass-transfer-limited rates of vaporization are roughly equal for the typical gas-temperature range in the plasma tail flame, so that at any height either process might limit the rate of vaporization. This similarity gives rise to a dynamic, competitive picture of plasma vaporization kinetics. 相似文献