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121.
Andrey I. Buvaylo Nikolay M. Dudarenko Igor O. Fritsky Jolanta
witek‐Kozowska 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(8):m331-m333
The title compound, [Ni(C2H8N2)3][Ni(C3HN3O2)2]·H2O, appears to be a modular associate consisting of two complex counter‐ions, containing bivalent nickel as the central atom in both cases, and a solvent water molecule. The NiII ion in the complex cation lies on the C2 crystallographic axis. Its coordination environment is formed by six N atoms of three ethylenediamine (en) molecules, representing a distorted octahedral geometry. The NiII ion in the complex anion occupies a position at the center of inversion. It exhibits a distorted square‐planar coordination geometry formed by four N atoms belonging to the deprotonated oxidoimine and amide groups of the two doubly charged 2‐cyano‐2‐(oxidoimino)acetamidate anions, situated in trans positions with respect to each other. In the crystal packing, the complex anions are linked by water molecules via hydrogen bonds between the amide O atoms and water H atoms, forming chains translated along the a direction. The [Ni(en)3]2+ cations fill empty spaces between the translational chains, connecting them by hydrogen bonds between the oxime and amide O atoms of the anions and the amine H atoms of the cations, forming layers along the ac plane. The water molecules provide connection between layers through N atoms of the cations, thus forming a three‐dimensional modular structure. 相似文献
122.
The morphological variety of crystal habits is due to differences in relative growth rates of faces of which the crystal is composed. For equilibrium, the growth rates of faces are proportional to the distances from the centre of the crystal to the respective hkl faces. According to the BFDH law, such distances are inversely proportional to the interplanar distances, therefore the observed crystal faces are those with the largest interplanar distances. This paper tries to explain some peculiarities of the crystal morphology deduced from the BFDH law and shows that the crystal geometry influences morphological importance of faces and because of crystal geometry, the faces of the largest interplanar distances are not necessarily the largest faces in the BFDH morphology. 相似文献
123.
Joanna Wezgowiec Marta Tsirigotis-Maniecka Jolanta Saczko Mieszko Wieckiewicz Kazimiera A. Wilk 《Molecules (Basel, Switzerland)》2021,26(19)
This study aimed to characterize the hydrogel micro- and macro-particles designed to deliver curcumin to human colon cancer cells (LoVo). Six series of vehicles based on sodium alginate (micro- and macro-particles, uncoated, coated with chitosan or gelatin) were synthesized. The uncoated microparticles were fabricated using an emulsion-based technique and the uncoated macroparticles with an extrusion technique, with both coupled with ionotropic gelation. The surface morphology of the particles was examined with scanning electron microscopy and the average size was measured. The encapsulation efficiency, moisture content, and swelling index were calculated. The release of curcumin from the particles was studied in an experiment simulating the conditions of the stomach, intestine, and colon. To evaluate the anticancer properties of such targeted drug delivery systems, the cytotoxicity of both curcumin-loaded and unloaded carriers to human colon cancer cells was assessed. The microparticles encapsulated much less of the payload than the macroparticles and released their content in a more prolonged manner. The unloaded carriers were not cytotoxic to LoVo cells, while the curcumin-loaded vehicles impaired their viability—more significantly after incubation with microparticles compared to macroparticles. Gelatin-coated or uncoated microparticles were the most promising carriers but their potential anticancer activity requires further thorough investigation. 相似文献
124.
Stanislaw Penczek Ryszard Szymanski Andrzej Duda Jolanta Baran 《Macromolecular Symposia》2003,201(1):261-270
Polymerization of cyclic esters leads to (bio)degradable polymers of the increasing industrial importance. These polymerizations are of the living nature, although chain transfer to polymer with chain scission may cause deviations from the livingness and introduce structural differences (e.g. in end-groups), important for physical properties. Two different systems are discussed. In the first one two living macromolecules react one with another and reproduce two living macromolecules, retaining the same reactivities and the same end-groups. Polymerizations of ϵ-caprolactone and lactide belong to this category. On the other hand, polymerization of cyclic carbonates proceeds with chain transfer, in which disproportionation of the living chains takes place: from two living macromolecules one “dead” and one “doubly active” can be formed. Conditions of retaining the livingness in terms of the ratios of the rate constants of transfer, reinitiation, and propagation are discussed. 相似文献
125.
Telechelic poly(1,3-oxazolidine-acetal)s with -CH2OH and -CHO groups were synthesized by polycondensation of the 2-amino-2-hydroxy-1,3-propanediol ( 1 ) (TRIS) with terephthaldehyde ( 2 ). The degree of polymerization (DP) was controlled by the ratio of 1 to 2 at the given reaction time. Characterization was achieved by 1H and 13C NMR and IR spectroscopy. The distribution of oxazolidine-acetal units in the polymer chain has been performed using ESI-MS. The activities of telechelic poly(oxazolidine-acetal) were determined in reaction oxidation (4-chloroperbenzoic acid), reduction (CH3MgCl) and nucleophilic substitution (acylation, alkylation). 相似文献
126.
Harald Krautscheid Eberhard Matern Jolanta Olkowska‐Oetzel Jerzy Pikies Gerhard Fritz 《无机化学与普通化学杂志》2001,627(4):675-678
Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XXII. The Formation of [η2‐{tBu–P=P–SiMe3}Pt(PR3)2] from (Me3Si)tBuP–P=P(Me)tBu2 and [η2‐{C2H4}Pt(PR3)2] (Me3Si)tBuP–P = P(Me)tBu2 reacts with [η2‐{C2H4}Pt(PR3)2] yielding [η2‐{tBu–P=P–SiMe3}Pt(PR3)2]. However, there is no indication for an isomer which would be the analogue to the well known [η2‐{tBu2P–P}Pt(PPh3)2]. The syntheses and NMR data of [η2‐{tBu–P=P–SiMe3}Pt(PPh3)2] and [η2‐{tBu–P=P–SiMe3}Pt(PMe3)2] as well as the results of the single crystal structure determination of [η2‐{tBu–P=P–SiMe3}Pt(PPh3)2] are reported. 相似文献
127.
Zofia apiska Urszula Szwedowicz Anna Choromaska Jolanta Saczko 《Molecules (Basel, Switzerland)》2022,27(8)
Gynecological carcinomas affect an increasing number of women and are associated with poor prognosis. The gold standard treatment plan is mainly based on surgical resection and subsequent chemotherapy with cisplatin, 5-fluorouracil, anthracyclines, or taxanes. Unfortunately, this treatment is becoming less effective and is associated with many side effects that negatively affect patients’ physical and mental well-being. Electroporation based on tumor exposure to electric pulses enables reduction in cytotoxic drugs dose while increasing their effectiveness. EP-based treatment methods have received more and more interest in recent years and are the subject of a large number of scientific studies. Some of them show promising therapeutic potential without using any cytotoxic drugs or molecules already present in the human body (e.g., calcium electroporation). This literature review aims to present the fundamental mechanisms responsible for the course of EP-based therapies and the current state of knowledge in the field of their application in the treatment of gynecological neoplasms. 相似文献
128.
Jolanta Wawrzyniak Magdalena Rudziska Marzena Gawrysiak-Witulska Krzysztof Przyby 《Molecules (Basel, Switzerland)》2022,27(8)
The need to maintain the highest possible levels of bioactive components contained in raw materials requires the elaboration of tools supporting their processing operations, starting from the first stages of the food production chain. In this study, artificial neural networks (ANNs) and response surface regression (RSR) were used to develop models of phytosterol degradation in bulks of rapeseed stored under various temperatures and water activity conditions (T = 12–30 °C and aw = 0.75–0.90). Among ANNs, networks based on a multilayer perceptron (MLP) and a radial basis function (RBF) were tested. The model input constituted aw, temperature and storage time, whilst the model output was the phytosterol level in seeds. The ANN-based modeling turned out to be more effective in estimating phytosterol levels than the RSR, while MLP-ANNs proved to be more satisfactory than RBF-ANNs. The approximation quality of the ANNs models depended on the number of neurons and the type of activation functions in the hidden layer. The best model was provided by the MLP-ANN containing nine neurons in the hidden layer equipped with the logistic activation function. The model performance evaluation showed its high prediction accuracy and generalization capability (R2 = 0.978; RMSE = 0.140). Its accuracy was also confirmed by the elliptical joint confidence region (EJCR) test. The results show the high usefulness of ANNs in predictive modeling of phytosterol degradation in rapeseeds. The elaborated MLP-ANN model may be used as a support tool in modern postharvest management systems. 相似文献
129.
130.
Rony Snyders Christophe Roberges Marie-Pierre Faure Jolanta E. Klemberg-Sapieha 《Surface science》2007,601(1):112-122
We studied the mechanism of adhesion between N2 plasma treated polypropylene (PP/N2) backing and a hybrid hydrogel (HG) produced by chemical crosslinking between poly(ethylene glycol) and soy albumin. The work of adhesion, measured by peel testing, was found to be 25 times higher for PP/N2 compared to untreated PP (≈5.0 J/m2 versus ≈0.2 J/m2). In order to understand the adhesion mechanism, we performed a detailed analysis of the surface chemical composition of PP and PP/N2 using X-ray photoelectron spectroscopy (XPS), chemical derivatization and attenuated total reflectance infra-red (ATR-IR) measurements. The results confirm incorporation of different nitrogen- (amine, amide,…) and oxygen- (hydroxyl, carboxyl,…) containing chemical groups on the PP/N2 surface. The derivatized functions were primary amine, hydroxyl, carboxyl and carbonyl groups. Chemical derivatization reactions validated the XPS results (except for carbonyl groups), and they clearly underlined the essential role of primary amine groups in the adhesion process. In fact, after derivatization of the amine functions, the work of adhesion was found to be 0.41 ± 0.12 J/m2. Participation of amine groups in the formation of covalent bonds at the interface between PP/N2 and HG was directly confirmed by ATR-IR measurements. 相似文献