全文获取类型
收费全文 | 215篇 |
免费 | 2篇 |
专业分类
化学 | 107篇 |
晶体学 | 2篇 |
力学 | 13篇 |
数学 | 50篇 |
物理学 | 45篇 |
出版年
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2016年 | 3篇 |
2014年 | 4篇 |
2013年 | 20篇 |
2012年 | 4篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 9篇 |
2008年 | 16篇 |
2007年 | 7篇 |
2006年 | 11篇 |
2005年 | 7篇 |
2004年 | 9篇 |
2003年 | 12篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1989年 | 2篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1966年 | 2篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1961年 | 1篇 |
1959年 | 1篇 |
1958年 | 2篇 |
1955年 | 1篇 |
1954年 | 1篇 |
1922年 | 1篇 |
排序方式: 共有217条查询结果,搜索用时 21 毫秒
1.
2.
3.
Dr. Ali Abdulkarim Marvin Nathusius Rainer Bäuerle Dr. Karl-Philipp Strunk Dr. Sebastian Beck Dr. Hans Joachim Räder Prof. Annemarie Pucci Dr. Christian Melzer Daniel Jänsch Dr. Jan Freudenberg Prof. Uwe H. F. Bunz Prof. Klaus Müllen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(1):281-288
The synthesis of unsubstituted oligo-para-phenylenes ( OPP ) exceeding para-hexaphenylene—in the literature often referred to as p-sexiphenyl—has long remained elusive due to their insolubility. We report the first preparation of unsubstituted para-nonaphenylenes ( 9PP s) by extending our precursor route to poly-para-phenylenes ( PPP ) to a discrete oligomer. Two geometric isomers of methoxylated syn- and anti-cyclohexadienylenes were synthesized, from which 9PP was obtained via thermal aromatization in thin films. 9PP was characterized via optical, infrared and solid-state 13C NMR spectroscopy as well as atomic force microscopy and mass spectrometry, and compared to polymeric analogues. Due to the lack of substitution, para-nonaphenylene, irrespective of the precursor isomer employed, displays pronounced aggregation in the solid state. Intermolecular excitonic coupling leads to formation of H-type aggregates, red-shifting emission of the films to greenish. 9PP allows to study the structure–property relationship of para-phenylene oligomers and polymers, especially since the optical properties of PPP depend on the molecular shape of the precursor. 相似文献
4.
Gabriella Leo Laura Cartechini Piero Pucci Antonio Sgamellotti Gennaro Marino Leila Birolo 《Analytical and bioanalytical chemistry》2009,395(7):2269-2280
The identification of proteinaceous components in paintings remains a challenging task for several reasons. In addition to
the minute amount of sample available, complex and variable chemical composition of the paints themselves, possible simultaneous
presence of several binders and contaminants, and degradation of the original materials due to aging and pollution are complicating
factors. We proposed proteomic strategies for the identification of proteins in binders of paintings that can be adapted to
overcome the requirements and difficulties presented by specific samples. In particular, we worked on (1) the development
of a minimally invasive method based on the direct tryptic cleavage of the sample without protein extraction; (2) the use
of microwave to enhance the enzymatic digestion yield, followed by the analysis of the peptide mixtures by nanoLC-MS/MS with
electrospray ionization (ESI). Moreover, as an additional tool to tackle the problem of contaminating proteins, we exploited
the possibility of generating an exclusion list of the mass signals that in a first run had been fragmented and that the mass
spectrometer had to ignore for fragmentation in a subsequent run. The methods, tested on model samples, allowed the identification
of milk proteins in a sample from paintings attributed to Cimabue and Giotto, thirteenth-century Italian masters, decorating
the vaults of the upper church in the Basilica of St. Francis in Assisi, Italy. 相似文献
5.
Edwin Laermann Fabrizio Pucci 《The European Physical Journal C - Particles and Fields》2012,72(11):1-13
The breaking of the taste symmetry is studied in the temperature range between 140 MeV to 550 MeV. In order to investigate this violation we have calculated the screening masses of the various taste states fitting the exponential decay of the spatial correlators. The computation has been performed using dynamical N f =2+1 gauge field configurations generated with the p4 staggered action along the Line of Constant Physics (LCP) defined by a pion mass m π of approximately 220 MeV and the kaon mass m K equals 500 MeV. For temperatures below the transition an agreement with the predictions of the staggered chiral perturbation theory has been found and no temperature effect can be observed on the taste violation. Above the transition the taste splitting still shows an $\mathcal{O}(a^{2})$ behavior but with a temperature-dependent slope. In addition to the analysis done for the pion multiplet we have performed an analogous computation for the light–strange and strange mesons and also looked at the scalar, vector and axial-vector channels to understand how the multiplets split at finite temperature. Finally the temperature dependence of the pion decay constant f π is investigated to get further information regarding the chiral symmetry restoration. 相似文献
6.
A material is of coaxial type if the Cauchy stress tensor T and the strain tensor B are coaxial for all deformations. Clearly a hyperelastic material is of coaxial type if and only if it is isotropic. Here we present a weaker definition of materials of coaxial type. Anisotropic materials may be of a coaxial type in a weak sense if for a given specific B we have that TB=BT. We denote these materials B-coaxial. We show that for transverse isotropic materials weak coaxial constitutive equations may be characterized using universal relations. We discuss the impact of B-coaxial materials in the modeling of soft tissues. We conclude that B-coaxial materials are a strong evidence that in real world materials two anisotropic invariants are always necessary to model in a meaningful and correct way single fiber reinforced materials. 相似文献
7.
M. A. Raggi C. Sabbioni V. Pucci N. Ghedini N. Calonghi G. Gerra 《Chromatographia》2001,53(7-8):409-413
Summary This study deals with the development of a new HPLC method for the determination of 3-methoxy-4-hydroxyphenylglycol (MHPG),
the main noradrenaline metabolite in human plasma. A Varian reversed-phase column (C8; 250 mm×4.6 mm i.d.; 5 μm particles) was used as the stationary phase and an aqueous solution of citric acid, 1-octanesulfonic
acid, EDTA, and methanol was used as the mobile phase. Coulometric electrochemical detection (ED) was used to obtain the highest
sensitivity. Isolation of MHPG from plasma was accomplished by means of a new solid-phase extraction procedure after a protein
precipitation step. The extraction yield of MHPG from plasma was very high (>97%). Linearity was observed in the 0.5–25 ng
mL−1 concentration range; the limit of detection was 0.2 ng mL−1 and the limit of quantitation was 0.5 ng mL−1. Repeatability (RSD,%) for plasma samples was found to be <3.2% and intermediate precision was <4.3%. The method was applied to the determination
of MHPG in the plasma of healthy subjects under experimentally-induced psychological stress. 相似文献
8.
Kanishka Perera Patrizia Pucci Csaba Varga 《NoDEA : Nonlinear Differential Equations and Applications》2014,21(3):441-451
We consider a nonlinear eigenvalue problem under Robin boundary conditions in a domain with (possibly noncompact) smooth boundary. The problem involves a weighted p–Laplacian operator and subcritical nonlinearities satisfying Ambrosetti–Rabinowitz type conditions. Using Morse theory and a cohomological local splitting as in Degiovanni et al. (Commun Contemp Math 12:475–486, 2010), we prove the existence of a nontrivial weak solution for all (real) values of the eigenvalue parameter. Our result is new even in the semilinear case p = 2 and complements some recent results obtained in Autuori et al. (Adv Anal Equ 18:1–48, 2013). 相似文献
9.
Iolinda Aiello Mauro Ghedini Annarita Grisolia Daniela Pucci Oriano Francescangeli 《Liquid crystals》2005,32(6):763-769
New Ni(II) and UO2(II) metallomesogens obtained from mesomorphic N,N'-salicyliden(3,3'-diamine-N-methyldipropylamine) ligands containing a pentadentate N3O2 chelating cavity and bearing two or four lateral substituents, are isolated and fully characterized. Some of the synthesized nickel and dioxouranium complexes show a SmC mesophase. To the best of our knowledge, these species are the first pentacoordinated Ni(II) and heptacoordinated UO2(II) metallomesogens to be reported. 相似文献
10.