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21.
ÜMMÜHAN OCAK HALIT KANTEKIN YAŞAR GÖK H. BASIR ŞENTÜRK 《Journal of inclusion phenomena and macrocyclic chemistry》2006,55(1-2):87-91
The selective liquid–liquid extraction of various transition metal cations from the aqueous phase to the organic phase was carried out using a 14-membered N2O2S2-macrobicycle. Metal picrates such as Pb2+, Co2+, Zn2+, Ni2+,Cu2+ and Cd2+ were used in this extraction studies. It was found that the ligand showed moderate selectivity towards Pb2+ only among the other metals. The extraction constant (log K
ex) was determined to be 13.8 for Pb2+ complex. 相似文献
22.
Nizam M. El-Ashgar Issa M. El-Nahhal Mohamed M. Chehimi Michel Delamar Florence Babonneau Jacques Livage 《Monatshefte für Chemie / Chemical Monthly》2006,41(1):263-275
A new porous solid macrocyclic 1,4,7,11,14-pentaazapentadecane-3,15-dione polysiloxane ligand system of the general formula
P–(CH2)3–C11H22O2N5 (where P represents [Si–O]n siloxane network) has been prepared by the reaction of polysiloxane-immobilized iminobis(N-(2-aminoethyl)acetamide) with 1,3-dibromopropane. The FTIR and XPS results confirm the introduction of the macrocyclic functional
ligand group into the polysiloxane network. The new macrocyclic polysiloxane ligand system exhibits high potential for the
uptake of metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+). 相似文献
23.
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25.
Katarína Mosnáčková Mohamed M. Chehimi Pavol Fedorko Mária Omastová 《Chemical Papers》2013,67(8):979-994
Conducting textiles of polyamide (PA) fabrics and polypyrrole (PPy) were prepared by in situ oxidative chemical polymerisation of pyrrole (Py) on the surface of PA textiles using FeCl3 as oxidant. The anionic surfactant, dodecylbenzenesulphonic acid, was used as co-dopant during Py polymerisation on the textile surface. The influence of the monomer amount and polymerisation conditions on formation of the conducting PPy layer, conductivity, morphology, and stability of the prepared PA/PPy was studied. The conductivity of modified textiles decreased rapidly after the washing process, so a special Py-functionalised silane (1-(3-(triethoxysilyl)propylamino)-3-(1-H-pyrrole-1-yl)propan-2-ol; SP) was synthesised and applied to the PA surface prior to PPy formation. The presence of SP on the PA surface after completion of the sol-gel process was verified by Fourier transform infrared spectroscopy with an attenuated total reflectance. Pyrrole polymerisation was subsequently applied to the SP pre-treated textile surface. The influence of SP concentration on both the fastness of the conducting layer after the washing process and stability of the electrical conductivity of the prepared PA/PPy samples was investigated. Surface conductivity of the samples treated and untreated by the sol-gel process of SP was measured both prior to and after washing of the prepared textiles. It was found that an application of 0.6 mass % of SP significantly improved the fastness of the PPy layers. Examination of the modified PA surface using scanning electron microscopy disclosed the differences in the formation of PPy on PA textiles when using SP and also showed differences on the PPy modified textile surface prior to and after washing. The method of X-ray photoelectron spectroscopy was used for a detailed study of the surface composition. It was confirmed that the pre-treatment with Py-functionalised triethoxysilane significantly influenced the chemical composition of the PA surface modified with PPy. 相似文献
26.
Noushine Shahidzadeh Mohamed M. Chehimi Farzaneh Arefi-Khonsari Jacques Amouroux Michel Delamar 《Plasmas and Polymers》1996,1(1):27-45
Acid-base properties of ammonia plasma-treated polypropylene (APTPP) were characterized by X-ray photoelectron spectroscopy
(XPS) in conjunction with the molecular probe technique and using chloroform (TCM) as a reference Lewis acid. It is shown
that TCM is retained by the basic surfaces of APTPP but not by the untreated PP. The retention of TCM is shown to be entirely
due to the formation of TCM:APTPP acid-base complexes. This is supported by the C12p3/2 binding energy (BE) and the shape of the Cl2p peak from the adsorbed TCM. ΔHAB, the heat of TCM:APTPP acid-base interaction was found to be in the range of 3.1–4.3 kcal/mol using a published Cl2p3/2 BE−ΔHAB correlation. This ΔHAB compares remarkably well with the values of 4.3–4.9 kcal/mol determined for TCM:amine complexes, and shows indeed that TCM
is complexed by nitrogen containing basic groups grafted at the surface. However, the TCM/N ratio has an optimal value up
to 1 second of plasma treatment and then decreases sharply, showing that less specific interaction sites are accessible at
the surface for longer treatment times. This parallels previous findings about the metallization of APTPP by aluminium which
was found to be optimal for treatment times lower than 1 second in our experimental conditions. This work shows that XPS can
now indeed be used to quantitatively assess the acid-base properties of modified polymer surfaces. 相似文献
27.
28.
S. Slomkowski D. Kowalczyk M. M. Chehimi M. Dealamar 《Colloid and polymer science》2000,278(9):878-883
The application of X-ray photoelectron spectroscopy (XPS) for studies of surface layers of objects with spherical shape was
investigated using as examples polystyrene and poly(styrene–acrolein) microspheres with attached human serum albumin (HSA).
The amounts of immobilized protein were determined by the standard biochemical Lowry method and by XPS, using the intensity
of the N1s signals of HSA as a basis for evaluation. The XPS data were treated by taking into account the spherical shape of the particles
analyzed (variable take-off angle of ejected electrons). The best agreement between the results of the biochemical and XPS
determinations was found assuming that for the average particle the takeoff angle varies from 0° to 72.7°. This reflects the
fact that in the multilayer arrangement of particles, placed onto the support of the XPS apparatus, the particles from the
upper layer partially screen the edges of the particles in the layer below.
Received: 23 November 1999 Accepted: 16 March 2000 相似文献
29.
B. Miksa S. Slomkowski M. M. Chehimi M. Delamar J.-P. Majoral A.-M. Caminade 《Colloid and polymer science》1999,277(1):58-65
Quartz plates were modified by consecutive immobilization of γ-aminopropyltriethoxysilane (APTS), phosphorus containing dendrimers
with aldehyde groups (generation 5 – G5), Starburst PAMAM dendrimers generation 4 (G4-PAMAM), and poly(styrene/acrolein/divinylbenzene)
microspheres [P(SAD)]. In this way surfaces with heterogeneity on molecular, macromolecular, and microscopic levels, and which
were equipped with functional amino or aldehyde groups were obtained. Surface layers were characterized by X-ray photoelectron
spectroscopy (XPS) and by contact-angle measurements. Analysis of XPS spectra revealed that the thickness of the layer of
G5 on the SiO2-APTS substrate was 3.7 nm, i.e., the thickness was typical for macromolecular dimensions. The average thickness of the layer
of PAMAM dendrimers on SiO2-APTS-G5 was found to be 0.35 and 0.29 nm, depending on whether calculations were based on attenuation of the intensity of
the Si2p or the P2p signal respectively. This thickness was unreasonably low for a monolayer of PAMAM dendrimers and indicated that the surface
of the SiO2-APTS-G5 substrate was incompletely covered with these macromolecules. The XPS method was also used for the determination
of the degree of coverage of the surface of a SiO2-APTS-G5-PAMAM plate with P(SAD) microspheres. The degree of coverage was found to be 0.60 and approaches the maximum theoretically
possible value (0.62) for microspheres attached chaotically and irreversibly to the surface in an arrangement one microsphere
thick. Subsequent coverage of the SiO2-APTS-G5-PAMAM-P(SAD) substrate with PAMAM dendrimers resulted in the formation of a PAMAM adlayer 3.2 nm thick, close to
the molecular dimensions of these dendrimers. Contact-angle measurements revealed considerable differences in the hydrophobicity
of the surfaces of the quartz plates, depending on their modification. Hydrophobicity increased in the order SiO2 < SiO2-APTS-G5-PAMAM < SiO2-APTS ≤ SiO2-APTS-G5 < SiO2-APTS-G5-PAMAM-P(SAD).
Received: 17 March 1998 Accepted: 14 September 1998 相似文献
30.
Tarik Matrab Bernadette Charleux Eva Cabet-deliry Mohamed M. Chehimi Michel Delamar 《Surface science》2007,601(11):2357-2366
Poly(n-butyl methacrylate), PBMA, chains were grafted by atom transfer radical polymerization (ATRP) from the surface of iron plates using electrochemically attached initiators based on diazonium salts providing an iron/polyphenylene/PBMA structure. This surface-initiated ATRP procedure was controlled by the addition of a small proportion of Cu++ deactivator, but in the absence of any sacrificial initiator. Combined XPS, IR and AFM experiments provide a powerful means for the characterization of the obtained complex iron/polyphenylene/PBMA layered structure. It is possible to measure the thickness of the brominated aryl structure covalently attached to iron. Concerning the PBMA brushes, their presence on the surface was confirmed by IRRAS. The brominated chain end could be traced by XPS testifying for the ATRP character of the polymerization and the thickness of the polymer brushes was determined. The controlled living ATRP character of the polymerization is confirmed through a linear correlation between the thickness of the layer and the degree of polymerization. Measurement of the grafting density of PBMA chains indicates that they are compactly packed and that, approximately, one brominated aryl chain out of two efficiently initiates ATRP. 相似文献