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211.
Poly(p‐phenylene) with Poly(ethylene glycol) Chains and Amino Groups as a Functional Platform for Controlled Drug Release and Radiotherapy 下载免费PDF全文
Bahar Guler Huseyin Akbulut Firat Baris Barlas Caner Geyik Dilek Odaci Demirkol Ahmet Murat Senisik Halil Armagan Arican Hakan Coskunol Suna Timur Yusuf Yagci 《Macromolecular bioscience》2016,16(5):730-737
Conventional cancer treatments such as chemotherapy, radiotherapy, or combination of these two result in side effects, which lower the quality of life of the patients. To overcome problems with these methods, altering the drug properties by conjugating them to carrier polymers has emerged. Such polymeric carriers also hold the potential to make tumor cells more sensitive to radiation therapy. Herein, poly(p‐phenylene) (PPP) polymer with poly(ethylene glycol) (PEG) chains and primary amino groups (PPP‐NH2‐g‐PEG) is synthesized and conjugated with anticancer drug Doxorubicin (DOX). pH dependent drug release experiments are performed at pH 5.3 and pH 7.4, respectively. Cell viability studies on human cervix adenocarcinoma cells show that lower doses of DOX inhibit cell proliferation when conjugated with nontoxic doses of PPP‐NH2‐g‐PEG polymer. Additionally, PPP‐NH2‐g‐PEG/Cys/DOX bioconjugate significantly increases radiosensitive properties of DOX. It is possible to use lower doses of DOX when conjugated to PPP‐NH2‐g‐PEG in combination with radiotherapy.
212.
Alphia R. Gataulina Damir A. Safin Timur R. Gimadiev Marina V. Pinus 《Transition Metal Chemistry》2008,33(7):921-924
Reaction of the potassium salts of podand-containing bis(dithiophosphonate)s [PhO(4-C6H4)P(S)(SH)OCH2CH2]2O (H
2
L) with Co(II), Ni(II) and Cd(II) in aqueous EtOH leads to complexes of formulae M2(L-S,S′)2. The structural formulae of the compounds were deduced by physico-chemical and spectroscopic methods. It was established
that complex Ni
2
L
2
recognizes CH2Cl2. 相似文献
213.
214.
The present study was aimed at elucidating the mechanism of aggregation in water of hydroxyl-terminated polyethylene glycol (PEG) of low molecular weight (600 g/mol). The results from fluorescence spectroscopy at different temperatures were consistent with surface tension measurements, suggesting aggregate formation. Indeed, the process of aggregation is accompanied by an increase in the fluorescence emission of a hydrophobic probe. So, PEG aggregates in the form of internal hydrated helices covered with CH(2) groups are shown to yield hydrophobic regions. These regions created upon PEG aggregation in water and at a temperature close to 35°C result from a balance between H bonding and entropic effects. By providing the first experimental evidence for hydrophobic mediation of aggregation with OH-terminated oxy-ethylene chains of low molecular weight, this study highlights their surfactant-like behaviour. 相似文献
215.
The glass transition is theoretically described in terms of a generic non-equilibrium thermodynamics approach employing De Donder's structural order parameter method, appropriate expressions for the relaxation behavior of glass-forming systems and a simplified but qualitative correct model of glass-forming melts with one order parameter related to the free volume of the system. Employing this approach the behavior of a variety of thermodynamic quantities describing glass-forming systems in vitrification and devitrification processes is interpreted theoretically. The present paper is devoted to the computation of the entropy, the entropy production and the glass transition temperature in dependence on the cooling and heating rates, varying latter parameter in a broad interval. A comparison with experimental results is given and some further consequences and possible extensions are discussed briefly. 相似文献
216.
Grinev TA Tscherbul TV Buchachenko AA Cavalli S Aquilanti V 《The journal of physical chemistry. A》2006,110(16):5458-5463
The matrices of electrostatic and spin-orbit Hamiltonians for the system of a 2P atom interacting with a closed shell diatomic molecule in uncoupled, coupled, and complex-valued representations for electronic diabatic basis functions are rederived, and the unitary transformations connecting them are given explicitly. The links to previous derivations are established and existing inconsistencies are identified and eliminated. It is proven that the block-diagonalization of a 6 x 6 matrix of the electronic Hamiltonian is a result of using the basis functions with well-defined properties with respect to time reversal. Consideration of time-reversal symmetry also enforces phase consistency relevant for applications to multisurface reactive scattering and photodetachment spectroscopy calculations, as well as for perspective studies of inelastic effects in cold and ultracold environments. These and further developments are briefly sketched. 相似文献
217.
Kirgöz UA Odaci D Timur S Merkoçi A Pazarlioğlu N Telefoncu A Alegret S 《Bioelectrochemistry (Amsterdam, Netherlands)》2006,69(1):128-131
The modification of a graphite-epoxy composite electrode (GECE) with bacterial cells along with an analytical application are presented. Pseudomonas putida DSM 50026 was used as a biological component and the measurement was based on the respiratory activity of the cells. The optimization of working conditions of resulting biosensor (including pH and temperature) was conducted and the limit of detection was calculated as 7 microM phenol based on the signal to noise ratio. Then the system was applied for xenobiotic detection. Resulting sample signals were found to be very similar with the standard solutions having the same concentration while the recoveries of the spiked samples were close to 100%. 相似文献
218.
A discret summation method [1] has been used to calculate the van der Waals dispersion interactions between an alkali metal atom and individual C60 fullerene molecules, as well as between an intercalated alkali metal atom and the face-centred-cubic lattice of solid fullerite. It is known [2, 3] that the conductivities observed in the doped C60 films vary considerably for different alkali atoms. Our interest was to investigate any correlation between these conductivities and the long range potential field behaviour. In the present study, we have obtained interaction potential curves of the C60 fullerene molecule including within its cage, as well the potential field topography within the overall C60 fullerite solid unit cell. We have found that for all intercalated alkali metals, except Cs, there are voids within the unit-cell of fullerite where the dopant experiences attractive interactions. Whereas on the other hand, inside the fullerene cage only Li and Na experience attractive forces. Importantly, it has been shown that the localization of the crystallographic sites [4] of doped alkali metals in fullerite coincide with the potential energy minima of long range van der Waals forces. 相似文献
219.
Timur Oikhberg 《Proceedings of the American Mathematical Society》1999,127(12):3659-3669
We give a characterization of operators on a separable Hilbert space of norm less than one that can be represented as products of orthogonal projections and give an estimate on the number of factors. We also describe the norm closure of the set of all products of orthogonal projections.
220.
Alzhan Z. Baimenov Ildar R. Fakhradiyev Dmitriy A. Berillo Timur Saliev Sergey V. Mikhalovsky Talgat S. Nurgozhin Vassilis J. Inglezakis 《Molecules (Basel, Switzerland)》2021,26(24)
The effectiveness of an amphoteric cryogel (AAC) as an oral sorbent (enerosorbent) for the treatment of acute poisoning of small animals (rats) with heavy metals (HMs) was studied in in vivo experiments. The morphological structure of the cryogel was examined using scanning electron microscopy/energy-dispersive X-ray analysis and confocal microscopy. The use of the cryogel in the treatment of rats administered an LD50 dose of Cd(NO3)2, CsNO3, Sr(NO3)2, or HgCl2 in aqueous solution showed their high survival rate compared to the control group, which did not receive such treatment. The histological and chemical analysis of internal tissues and the biochemical analysis of the blood of the experimental animals showed the effectiveness of the cryogel in protecting the animals against the damaging effect of HMs on the organism comparable with unithiol, a chelating agent based on 2,3-dimercapto-1-propane sulfonic acid sodium salt (DMPS) approved for the treatment of acute poisoning with some heavy metals. 相似文献