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61.
D. Czakis-Sulikowska J. Radwańska-Doczekalska M. Markiewicz 《Journal of Thermal Analysis and Calorimetry》2000,60(1):145-151
The mixed 2,4'-bipyridine-oxalato complexes of the formulae M(2,4'-bipy)2 C2 O4 2H2 O (M (II)=Mn, Co, Ni, Cu; 2,4'-bipyridine=2,4'-bipy or L ; C2 O2–
4 =ox) have been prepared and characterized. IR data show that the 2,4'-bipy coordinated with these metals(II) via the least
hindered (4')N atom; that oxalate group acts as bidentate chelating ligand. Room temperature magnetic moments are normal for
the orbital singlet states. The thermal decomposition of these complexes was investigated by TG, DTA and DTG in air. The endothermic
or exothermic character of the decomposition of ML2 (ox)2H2 O was discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
62.
D. Czakis-Sulikowska J. Radwańska-Doczekalska A. Czylkowska M. Markiewicz A. Broniarczyk 《Journal of Thermal Analysis and Calorimetry》2006,86(2):327-335
New mixed-ligand complexes with empirical
formulae: Mn(2-bpy)1.5L2·2H2O,
M(2-bpy)2L2·3H2O
(M(II)=Co, Cu), Ni(2-bpy)3L2·4H2O
and M(2,4’-bpy)2L2·2H2O
(where 2-bpy=2,2’-bipyridine, 2,4’-bpy=2,4’-bipyridine; L=HCOO– ) have been
obtained in pure solid-state. The complexes were characterized by chemical
and elemental analysis, IR and VIS spectroscopy, conductivity (in methanol
and dimethylsulfoxide). The way of metal-ligand coordination discussed. The
formate and 2,4’-bpy act as monodentate ligands and 2-bpy as chelate
ligand. The new complexes with ligand isomerism were identified. During heating
the complexes lose water molecules in one or two steps. Thermal decomposition
after dehydration is multistage and yields corresponding metal oxides as final
products. A coupled TG-MS system was used to analysis principal volatile thermal
decomposition (or fragmentation) products of Ni(2,4’-bpy)2(HCOO)2·2H2O under dynamic air or argon atmosphere. 相似文献
63.
Nonlinear Dynamics of Floating Cranes 总被引:7,自引:0,他引:7
The nonlinear dynamic responses of moored crane vessels to regular wavesare investigated experimentally and theoretically. The main subject ofinterest are nonlinear phenomena like bifurcations and the existence ofmultiple attractors. In the experimental part of the work, a mooredmodel of a crane vessel has been excited by regular waves in a wavetank. A special mechanism has been developed to model the nonlinearbehavior of real mooring systems. The theoretical part of the workconcerns the mathematical modeling of the floating cranes. Twomathematical models of different levels of complexity are presented. Twodifferent tools are used to systematically determine the responses ofthe systems to periodic forcing of waves. Firstly, the path-followingtechniques in combination with numerical integration of equations ofmotion applied to a full nonlinear model give insight into the dynamicsin time domain. Secondly, the multiple scales method allows for ananalytical investigation of simplified nonlinear models in frequencydomain. Many results of computations for two crane vessels, barge andship, are presented. Special attention is paid to oscillations near thefrequencies of primary resonances and to subharmonic motions. Anexcellent agreement is found between the results of time-domain andfrequency-domain analysis. The computational examples chosen correspondto the models used not only in the present experiments but in theexperiments of others as well. The results presented in the work allow usto draw several important conclusions concerning the dynamic behavior offloating cranes during offshore operations. Both the developed modelsand the analytical tools can be used to identify the limits of theoperating range of floating cranes. 相似文献
64.
We propose a new method for computing a large number of eigenpairs in the interior of the spectrum for conservative gyroscopic eigenproblems by the nonlinear Arnoldi method combined with a localized version of safeguarded iteration. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
65.
Katarzyna Markiewicz Anna Biak-Bieliska Paulina ukaszewicz Piotr Stepnowski Joanna Doonek 《Molecules (Basel, Switzerland)》2021,26(6)
Nowadays anticancer drugs (ADs), like other pharmaceuticals, are recognized as new emerging pollutants, meaning that they are not commonly monitored in the environment; however, they have great potential to enter the environment and cause adverse effects there. The current scientific literature highlights the problem of their presence in the aquatic environment by publishing more and more results on their analytics and ecotoxicological evaluation. In order to properly assess the risk associated with the presence of ADs in the environment, it is also necessary to investigate the processes that are important in understanding the environmental fate of these compounds. However, the state of knowledge on mobility of ADs in the environment is still very limited. Therefore, the main aim of our study was to investigate the sorption potential of two anticancer drugs, 5-fluorouracil (5-FU) and methotrexate (MTX), onto different soils. Special attention was paid to the determination of the influence of pH and ionic strength as well as presence of co-contaminants (cadmium (Cd2+) and another pharmaceutical—metoprolol (MET)) on the sorption of 5-FU and MTX onto soil. The obtained distribution coefficient values (Kd) ranged from 2.52 to 6.36 L·kg−1 and from 6.79 to 12.94 L·kg−1 for 5-FU and MTX, respectively. Investigated compounds may be classified as slightly or low mobile in the soil matrix (depending on soil). 5-FU may be recognized as more mobile in comparison to MET. It was proved that presence of other soil contaminants may strongly influence their mobility in soil structures. The investigated co-contaminant (MET) caused around 25-fold increased sorption of 5-FU, whereas diminished sorption of MTX. Moreover, the influence of environmental conditions such as pH and ionic strength on their sorption has been clearly demonstrated. 相似文献
66.
Practical Iron‐ and Cobalt‐Catalyzed Cross‐Coupling Reactions between N‐Heterocyclic Halides and Aryl or Heteroaryl Magnesium Reagents 下载免费PDF全文
Dr. Olesya M. Kuzmina Dr. Andreas K. Steib M. Sc. Sarah Fernandez Willy Boudot Dr. John T. Markiewicz Prof. Dr. Paul Knochel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(22):8242-8249
The reaction scope of iron‐ and cobalt‐catalyzed cross‐coupling reactions in the presence of isoquinoline (quinoline) in the solvent mixture tBuOMe/THF has been further investigated. Various 2‐halogenated pyridine, pyrimidine, and triazine derivatives were arylated under these mild conditions in excellent yields. The presence of isoquinoline allows us to perform Fe‐catalyzed cross‐coupling reactions between 6‐chloroquinoline and aryl magnesium reagents. Furthermore, it was found that the use of 10 % N,N‐dimethylquinoline‐8‐amine increases the yields of some Co‐catalyzed cross‐coupling reactions with chloropyridines bearing electron‐withdrawing substituents. 相似文献
67.
Fourest T. Bouda P. Fletcher L. C. Notta-Cuvier D. Markiewicz E. Pierron F. Langrand B. 《Experimental Mechanics》2020,60(2):235-248
Experimental Mechanics - In the present work Image-Based Inertial Impact (IBII) tests are performed on Ti6Al4V material. The IBII test uses an impact on the edge of the specimen to generate a short... 相似文献
68.
Sylwia Ostrowska Bartosz Markiewicz Karolina Wąsikowska Natalia Bączek Juliusz Pernak Krzysztof Strzelec 《Comptes Rendus Chimie》2013,16(8):752-760
In this work, the application of an epoxy resin cured with ammonium ionic liquids as a support for palladium complex catalyst is reported. Supports based on epoxy resin were obtained as a result of the use of ionic liquids: didecyldimethylammonium tetrafluoroborate [d2m2am][BF4], 1-methyltheobromine tetrafluoroborate [mthb][BF4], didecyldimethylammonium theobrominate [d2m2am][thb], didecyldimethylammonium theophyllinate [d2m2am][thp] as cross-linking agents. The characterization of polymeric supports and heterogenized palladium catalysts has involved research methods like time-of-flight secondary ion mass spectrometry (TOF-SIMS), infrared spectroscopy (IR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS). The activity and stability during long-term use of the investigated catalytic systems were tested in a model Heck reaction. The influence of the type of ILs used as epoxy hardeners on the catalytic properties of epoxy-supported palladium catalysts is discussed. 相似文献
69.
Wanda Radecka‐Paryzek Izabela Pospieszna‐Markiewicz Maciej Kubicki 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):o399-o401
In the title salt, also known as pentane‐1,5‐diammonium dichloride, C5H16N22+·2Cl−, the cation exists in an ideal fully extended conformation and lies on a mirror plane in the space group Pbam. In the crystal structure, layers of cations are hydrogen bonded with Cl− anions, which occupy the space between the layers. This kind of packing leads to a short unit‐cell parameter of 4.463 (1) Å. This structure is another case of centro–non‐centrosymmetric ambiguity; the best results were obtained in a centrosymmetric space group, with the disordered NH3 groups accounting for the non‐centrosymmetric `component'. 相似文献
70.
D. Czakis-Sulikowska J. Radwańnska-Doczekalska M. Markiewicz M. Pietrzak 《Journal of Thermal Analysis and Calorimetry》2008,93(3):789-794
New mixed ligand complexes of the following stoichiometric formulae: M(2-bpy)2(RCOO)2·nH2O, M(4-bpy)(RCOO)2·H2O and M(2,4’-bpy)2(RCOO)2·H2O (where M(II)=Zn, Cd; 2-bpy=2,2’-bipyridine, 4-bpy=4,4′-bipyridine, 2,4′-bpy=2,4′-bipyridine; R=C2H5; n=2 or 4) were prepared in pure solid-state. These complexes were characterized by chemical and elemental analysis, IR and
conductivity studies.
Thermal behaviour of compounds was studied by means of DTA, DTG, TG techniques under static conditions in air. The final products
of pyrolysis of Cd(II) and Zn(II) compounds were metal oxides MO. A coupled TG/MS system was used to analyse of principal
volatile products of thermal decomposition or fragmentation of Zn(4-bpy)(RCOO)2·H2O under dynamic air and argon atmosphere.
The principal species correspond to: C+, CH+, CH3
+, C2H2
+, HCN+, C2H5
+ or CHO+, CH2O+ or NO+, CO2
+, 13C16O2
+ and 12C16O18O+ and others; additionally CO+ in argon atmosphere. 相似文献