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181.
Although the formulation of the nonlinear theory of H
∞ control has been well developed, solving the Hamilton–Jacobi–Isaacs equation remains a challenge and is the major bottleneck
for practical application of the theory. Several numerical methods have been proposed for its solution. In this paper, results
on convergence and stability for a successive Galerkin approximation approach for nonlinear H
∞ control via output feedback are presented. An example is presented illustrating the application of the algorithm. 相似文献
182.
M. Ramos Silva A. Matos Beja L. Alte da Veiga J. A. Paixo A. J. F. N. Sobral N. G. C. L. Rebanda A. M. d'A. Rocha Gonsalves 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1136-1138
The title compound, C27H37N, which is intended to be included in the structure of a sulfonamide porphyrin for the preparation of Langmuir–Blodgett films, consists of a dodecyl chain linked to an anthracene molecule through an aminomethyl group. The angle between the least‐squares plane of the anthracene and the dodecyl chain is 11.44 (8)°. The molecules are arranged in zigzag layers head‐to‐head, with the hydrocarbon chains side‐by‐side. The structure is stabilized by C—H?π interactions, the strongest having an H?centroid distance of 2.63 Å. 相似文献
183.
M. Ramos Silva A. Matos Beja J. A. Paixo L. Alte da Veiga A. J. F. N. Sobral A. M. d'A. Rocha Gonsalves 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1263-1264
In the title compound, C16H17NO4, the benzyloxycarbonyl group is anti to the pyrrolic N atom. The molecules are joined into head‐to‐head dimers by hydrogen bonds involving the carboxylic acid groups. There is orientational disorder of these groups over two positions with approximately equal occupancy. A weaker hydrogen bond between the pyrrolic N atom and the carbonyl O atom of the benzyloxycarbonyl group joins the dimers into chains running parallel to the [110] direction. 相似文献
184.
Jos S. Cmara Rosa Perestrelo Cristina V. Berenguer Carolina F. P. Andrade Telma M. Gomes Basit Olayanju Abuzar Kabir Cristina M. R. Rocha Jos Antnio Teixeira Jorge A. M. Pereira 《Molecules (Basel, Switzerland)》2022,27(9)
Green extraction techniques (GreETs) emerged in the last decade as greener and sustainable alternatives to classical sample preparation procedures aiming to improve the selectivity and sensitivity of analytical methods, simultaneously reducing the deleterious side effects of classical extraction techniques (CETs) for both the operator and the environment. The implementation of improved processes that overcome the main constraints of classical methods in terms of efficiency and ability to minimize or eliminate the use and generation of harmful substances will promote more efficient use of energy and resources in close association with the principles supporting the concept of green chemistry. The current review aims to update the state of the art of some cutting-edge GreETs developed and implemented in recent years focusing on the improvement of the main analytical features, practical aspects, and relevant applications in the biological, food, and environmental fields. Approaches to improve and accelerate the extraction efficiency and to lower solvent consumption, including sorbent-based techniques, such as solid-phase microextraction (SPME) and fabric-phase sorbent extraction (FPSE), and solvent-based techniques (μQuEChERS; micro quick, easy, cheap, effective, rugged, and safe), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), in addition to supercritical fluid extraction (SFE) and pressurized solvent extraction (PSE), are highlighted. 相似文献
185.
Thierry Wesley de Albuquerque Aguiar Jos Josenildo Batista Silvio Assis de Oliveira Ferreira Maíra de Vasconcelos Lima Sampaio Dewson Rocha Pereira Magda Rhayanny Assuno Ferreira Luiz Alberto Lira Soares Ana Maria Mendona de Albuquerque Melo Mnica Camelo Pessoa de Azevedo Albuquerque Andr de Lima Aires Hallysson Douglas Andrade de Araújo Luana Cassandra Breitenbach Barroso Coelho 《Molecules (Basel, Switzerland)》2022,27(15)
Biomphalaria glabrata snails constitute the main vector of schistosomiasis in Brazil, and Bauhinia monandra Kurz, the leaves of which contain BmoLL lectin with biocidal action, is a plant widely found on continents in which the disease is endemic. This work describes the composition of B. monandra preparations and the effect on embryos and adult snails, their reproduction parameters and hemocytes. We also describe the results of a comet assay after B. glabrata exposure to sublethal concentrations of the preparations. Additionally, the effects of the preparations on S. mansoni cercariae and environmental monitoring with Artemia salina are described. In the chemical evaluation, cinnamic, flavonoid and saponin derivatives were detected in the two preparations assessed, namely the saline extract and the fraction. Both preparations were toxic to embryos in the blastula, gastrula, trochophore, veliger and hippo stages (LC50 of 0.042 and 0.0478; 0.0417 and 0.0419; 0.0897 and 0.1582; 0.3734 and 0.0974; 0.397 and 0.0970 mg/mL, respectively) and to adult snails (LC50 of 6.6 and 0.87 mg/mL, respectively), which were reproductively affected with decreased egg deposition. In blood cell analysis, characteristic cells for apoptosis, micronucleus and binucleation were detected, while for comet analysis, different degrees of nuclear damage were detected. The fraction was able to cause total mortality of the cercariae and did not present environmental toxicity. Therefore, B. monandra preparations are promising in combating schistosomiasis since they can control both the intermediate host and eliminate the infectious agent, besides being safe to the environment. 相似文献
186.
Saldanha Renata Leal Gomes Bhetina Cunha da Rocha Torres Gabriel de Lima Brenda Raffaela de Castro José Adilson da Silva Ladário Ferreira Elivelton Alves 《Journal of Solid State Electrochemistry》2020,24(8):1991-1998
Journal of Solid State Electrochemistry - The anodic oxide on titanium can be thickened by anodization, with the consequent corrosion properties of this oxide depending on many variables, including... 相似文献
187.
Favaro D. I. T. Rocha F. R. Angelini M. A Henriques H. R. Soares J. S. Silva P. S. C. Oliveira S. M. B. 《Journal of Radioanalytical and Nuclear Chemistry》2018,316(2):805-818
Journal of Radioanalytical and Nuclear Chemistry - Concentration of metals in 15 bottom sediment samples from Tietê River, a significantly polluted river, were assessed. Total and partial... 相似文献
188.
Samuel Guieu Ctia I. C. Esteves Joo Rocha Artur M. S. Silva 《Molecules (Basel, Switzerland)》2020,25(24)
A family of iminoboronates was prepared through a one-pot multicomponent reaction, starting from boronic acid, anthranilic acid, and different salicylaldehydes. Their synthesis was straightforward and the complexes were obtained in good to excellent yields. Their photophysical properties were assessed in a diluted solution, and the complexes proved to be faintly luminescent. These chelates demonstrated remarkable Aggregation-Induced Emission Enhancement, which was rationalized using crystal structures. 相似文献
189.
Dr. Manuel Souto Dr. Karol Strutyński Dr. Manuel Melle-Franco Prof. João Rocha 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(48):10912-10935
Electroactive organic molecules have received a lot of attention in the field of electronics because of their fascinating electronic properties, easy functionalization and potential low cost towards their implementation in electronic devices. In recent years, electroactive organic molecules have also emerged as promising building blocks for the design and construction of crystalline porous frameworks such as metal–organic frameworks (MOFs) and covalent-organic frameworks (COFs) for applications in electronics. Such porous materials present certain additional advantages such as, for example, an immense structural and functional versatility, combination of porosity with multiple electronic properties and the possibility of tuning their physical properties by post-synthetic modifications. In this Review, we summarize the main electroactive organic building blocks used in the past few years for the design and construction of functional porous materials (MOFs and COFs) for electronics with special emphasis on their electronic structure and function relationships. The different building blocks have been classified based on the electronic nature and main function of the resulting porous frameworks. The design and synthesis of novel electroactive organic molecules is encouraged towards the construction of functional porous frameworks exhibiting new functions and applications in electronics. 相似文献
190.
Lucas H. Martorano Jordana T. Brito Ana Carolina F. de Albuquerque Carlos Magno Rocha Ribeiro Rodolfo Goetze Fiorot José Walkimar de Mesquita Carneiro Fabio Luiz Paranhos Costa Alessandra L. Valverde Fernando Martins dos Santos Junior 《Magnetic resonance in chemistry : MRC》2022,60(4):434-441
Recently, structural elucidation of natural products has undergone a revolution. The combined use of different modern spectroscopic methods has allowed obtaining a complete structural assignment of natural products using small amounts of sample. However, despite the extraordinary ongoing advances in spectroscopy, the mischaracterization of natural products has been and remains a recurrent problem, especially when the substance presents several stereogenic centers. The misinterpretation of nuclear magnetic resonance (NMR) data has resulted in frequent reports addressing structural reassignment. In this context, a great effort has been devoted to developing quantum chemical calculations that simulate NMR parameters accurately, allowing to achieve a more precise spectral interpretation. In this work, we employed a protocol for theoretical calculations of 1H NMR chemical shifts and coupling constants using density functional theory (DFT), followed by the application of the DP4+ method to revisit the structure of Heliannuol L, a member of the Heliannuol class, isolated from Helianthus annuus. Our results indicate that the originally proposed structure of Heliannuol L needs a stereochemical reassignment, placing the hydroxyl bonded to C10 in the opposite side of the methyl and hydroxyl groups bonded to C7 and C8, respectively. 相似文献