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81.
Cleomacio Miguel da Silva Carlos Eduardo de Oliveira Costa Júnior 《The International journal of environmental studies》2019,76(3):357-369
The counties of Pedra and Venturosa have one of the largest natural radioactive occurrences of Brazil. The large farms producing milk in the state of Pernambuco are located in these counties. The forage plants cultivated on those farms have high concentrations of 228Ra, a naturally occurring descending radionuclide from the 232Th series. The 228Ra is transferred to the forage plants, and once ingested by the lactating cow, this radionuclide is rapidly transferred to the milk. Thus, milk intake is an important route for 228Ra of incorporation by the human consumer and may induce the appearance of bone sarcoma. Accordingly, the aim of the present study was to determine the concentrations of 228Ra in milk produced in the Pedra and Venturosa farms, in order to estimate the risk of ingestion in the local population. The 228Ra was determined by actin-228 (228Ac) using the radiochemical technique of barium sulphate precipitate (BaSO4). The milk samples had concentrations of 228Ra ranging from 61 to 1338 mBq.l?1, which corresponded to the cumulative equivalent dose ranging from 0.04 to 0.1 Sv. Although the doses were low, regulatory and protective measures should be taken to study the radiotoxic effects of 228Ra in subjects in the public. 相似文献
82.
The quantity variations and the structural changes of the α 1,4 —α 1,6 glucopolysaccharides contained in the endosperm of sweet corn, waxy and amylose extender maize genotypes, were studied during early germination. The α 1,4 —α 1,6 glucopolysaccharides were fractionated according to their branching degree. The results obtained showed that: the degradation pattern of the α 1,4 —α 1,6 glucopolysaccharides was similar for the different corn genotypes studied. In addition, soluble dextrins or partial degradation products were not detected, but reducing sugars were accumulated. Furthermore, the structure of the remaining polysaccharides was similar to those present in the non germinating seed. These results led us to propose that once a polysaccharide molecule was used as the substrate by degradative enzymes during germination, that molecule was totally degraded. 相似文献
83.
Seigo Nagashima Anderson Azevedo Dutra Mayara Pezzini Arantes Rafaela Chiuco Zeni Carolline Konzen Klein Flvia Centenaro de Oliveira Giulia Werner Piper Isadora Drews Brenny Marcos Roberto Curcio Pereira Rebecca Benicio Stocco Ana Paula Camargo Martins Eduardo Morais de Castro Caroline Busatta Vaz de Paula Andra Novaes Moreno Amaral Cleber Machado-Souza Cristina Pellegrino Baena Lucia Noronha 《International journal of molecular sciences》2022,23(3)
Mast cells (MCs) have relevant participation in inflammatory and vascular hyperpermeability events, responsible for the action of the kallikrein–kinin system (KKS), that affect patients inflicted by the severe form of COVID-19. Given a higher number of activated MCs present in COVID-19 patients and their association with vascular hyperpermeability events, we investigated the factors that lead to the activation and degranulation of these cells and their harmful effects on the alveolar septum environment provided by the action of its mediators. Therefore, the pyroptotic processes throughout caspase-1 (CASP-1) and alarmin interleukin-33 (IL-33) secretion were investigated, along with the immunoexpression of angiotensin-converting enzyme 2 (ACE2), bradykinin receptor B1 (B1R) and bradykinin receptor B2 (B2R) on post-mortem lung samples from 24 patients affected by COVID-19. The results were compared to 10 patients affected by H1N1pdm09 and 11 control patients. As a result of the inflammatory processes induced by SARS-CoV-2, the activation by immunoglobulin E (IgE) and degranulation of tryptase, as well as Toluidine Blue metachromatic (TB)-stained MCs of the interstitial and perivascular regions of the same groups were also counted. An increased immunoexpression of the tissue biomarkers CASP-1, IL-33, ACE2, B1R and B2R was observed in the alveolar septum of the COVID-19 patients, associated with a higher density of IgE+ MCs, tryptase+ MCs and TB-stained MCs, in addition to the presence of intra-alveolar edema. These findings suggest the direct correlation of MCs with vascular hyperpermeability, edema and diffuse alveolar damage (DAD) events that affect patients with a severe form of this disease. The role of KKS activation in events involving the exacerbated increase in vascular permeability and its direct link with the conditions that precede intra-alveolar edema, and the consequent DAD, is evidenced. Therapy with drugs that inhibit the activation/degranulation of MCs can prevent the worsening of the prognosis and provide a better outcome for the patient. 相似文献
84.
Luis M. Montao Bettina Sommer Juan C. Gomez-Verjan Genaro S. Morales-Paoli Gema Lizbeth Ramírez-Salinas Hctor Solís-Chagoyn Zuly A. Sanchez-Florentino Eduardo Calixto Gloria E. Prez-Figueroa Rohan Carter Ruth Jaimez-Melgoza Bianca S. Romero-Martínez Edgar Flores-Soto 《International journal of molecular sciences》2022,23(8)
Theophylline (3-methyxanthine) is a historically prominent drug used to treat respiratory diseases, alone or in combination with other drugs. The rapid onset of the COVID-19 pandemic urged the development of effective pharmacological treatments to directly attack the development of new variants of the SARS-CoV-2 virus and possess a therapeutical battery of compounds that could improve the current management of the disease worldwide. In this context, theophylline, through bronchodilatory, immunomodulatory, and potentially antiviral mechanisms, is an interesting proposal as an adjuvant in the treatment of COVID-19 patients. Nevertheless, it is essential to understand how this compound could behave against such a disease, not only at a pharmacodynamic but also at a pharmacokinetic level. In this sense, the quickest approach in drug discovery is through different computational methods, either from network pharmacology or from quantitative systems pharmacology approaches. In the present review, we explore the possibility of using theophylline in the treatment of COVID-19 patients since it seems to be a relevant candidate by aiming at several immunological targets involved in the pathophysiology of the disease. Theophylline down-regulates the inflammatory processes activated by SARS-CoV-2 through various mechanisms, and herein, they are discussed by reviewing computational simulation studies and their different applications and effects. 相似文献
85.
Eduardo Cuevas Abigail Uribe-Martínez 《International journal of remote sensing》2018,39(11):3608-3627
Recently, the need for quantitative information on the spatiotemporal distribution of floating macroalgae, particularly the two species of genus Sargassum, has grown because of blooms of these species in the Gulf of Mexico and Caribbean Sea. Remote sensing is one of the most frequently used tools to assess pelagic Sargassum distribution. The purpose of this study was to implement a methodological approach to detect floating algae in an efficient and replicable manner at a moderate cost. We analyzed Landsat 8 imagery, from which we calculated four vegetation indices and one floating-algae index to implement a supervised classification, together with the bands 2 and 5, using the Random Forest algorithm. The analysis was performed monthly from 2014 to 2015 for the northeastern Yucatan Peninsula, Mexico, with a total of 91 analyzed images. The quantitative performance metrics of the classifier (overall, Kappa and Tau) were greater than 80%, whereas bands 2 and 5 as well as the atmospherically resistant vegetation index made the greatest contributions to the classifications. During summer 2015, more than 4,000 ha of Sargassum coverage per image were observed, which was substantially greater than that over the rest of the period. This approach constitutes a transferable alternative for the systematic detection of Sargassum, which enables a quantitative semi-automated time series comparison. 相似文献
86.
Ana Beatriz Aguiar Sanford Leidivan Sousa da Cunha Caio Bezerra Machado Flvia Melo Cunha de Pinho Pessoa Abigail Nayara dos Santos Silva Rodrigo Monteiro Ribeiro Fabiano Cordeiro Moreira Manoel Odorico de Moraes Filho Maria Elisabete Amaral de Moraes Lucas Eduardo Botelho de Souza Andr Salim Khayat Caroline Aquino Moreira-Nunes 《International journal of molecular sciences》2022,23(15)
The circadian clock (CC) is a daily system that regulates the oscillations of physiological processes and can respond to the external environment in order to maintain internal homeostasis. For the functioning of the CC, the clock genes (CG) act in different metabolic pathways through the clock-controlled genes (CCG), providing cellular regulation. The CC’s interruption can result in the development of different diseases, such as neurodegenerative and metabolic disorders, as well as cancer. Leukemias correspond to a group of malignancies of the blood and bone marrow that occur when alterations in normal cellular regulatory processes cause the uncontrolled proliferation of hematopoietic stem cells. This review aimed to associate a deregulated CC with the manifestation of leukemia, looking for possible pathways involving CG and their possible role as leukemic biomarkers. 相似文献
87.
88.
Cátia L. Ücker Luciano T. Gularte Cristian D. Fernandes Vitor Goetzke Eduardo Ceretta Moreira Cristiane W. Raubach Mario L. Moreira Sergio S. Cava 《Journal of the American Ceramic Society》2019,102(4):1884-1892
This work demonstrates the obtention of Nb2O5 nanoparticles by the microwave-assisted hydrothermal synthesis method in a fast way and with the use of low temperatures. The heat treatment applied on the samples promotes the phase change in Nb2O5 from pseudohexagonal to orthorhombic as the temperature increases, with a particle size between 7.3 and 32.6 nm. The band gap of the samples decreases with increasing temperature, obtaining a minimum value of 3.04 eV at 800°C. Dye-sensitized solar cells (DSSC) were assembled using the Doctor Blade coating technique. The photovoltaic parameters of open-circuit voltage (Voc) and short-circuit current density (Jsc) were evaluated. The cells showed a photovoltaic response, demonstrating that Nb2O5 has a semiconductive potential. The DSSC have different characteristics regarding Jsc and Voc, showing that according to the temperature increase in the semiconductor sample, there is a decrease in the photovoltaic parameters of the cells. 相似文献
89.
Rodrigo Battisti Eduardo Hafemann Carlos Alberto Claumann Ricardo Antonio Francisco Machado Cintia Marangoni 《Polymer Engineering and Science》2019,59(5):891-898
This study provides a novel value‐added utilization of the agroindustrial waste of royal palm tree leaf sheath to produce cellulose acetate. One of the motivations of this work was the fact that Brazil is one of the largest heart of palm producers in the world. However, as a result of extraction and processing, tons of waste are generated and discharged to the environment. Such waste is rich in lignocellulosic material, which could be reused to obtain derivatives of interest and commercial value. The synthesis of cellulose acetate was performed through a homogeneous acetylation reaction. Three different conditions were tested for delignification of the raw material, which resulted in a reduction in lignin content from 17.75 to 7.72%. The highest yield of cellulose acetate reached 99.5%, with degree of substitutions ranging between 2.08 and 2.82, which indicates satisfactory conversion. The Fourier transform infrared spectrum showed that practically all hydroxyl groups were replaced by acetate groups; this was also confirmed by nuclear magnetic resonance analysis. X‐ray diffraction analysis showed that the cellulose acetate crystallinity index was 8.9%. This demonstrates the viable potential of cellulose acetate production with low cost and use of highly available agroindustrial waste. POLYM. ENG. SCI., 59:891–898, 2019. © 2018 Society of Plastics Engineers 相似文献
90.
Eduardo Di Mauro Matteo Camaggi Nils Vandooren Caleb Bayard Jordan De Angelis Alessandro Pezzella Bill Baloukas Richard Silverwood Abdellah Ajji Christian Pellerin Clara Santato 《Polymer International》2019,68(5):984-991
In the human body, the black‐brown biopigment eumelanin blocks harmful ultraviolet (UV) radiation. In the plastics industry, additives are often added to polymers to increase their UV‐absorption properties. We herein report an assessment of the biopigment eumelanin as a nature‐inspired additive for plastics to enhance their UV absorption. Since eumelanin is produced by natural sources and is nontoxic, it is an interesting candidate in the field of sustainable plastic additives. In this work, the eumelanin‐containing films of commercial ethylene–vinyl acetate copolymer, a plastic used for packaging applications, were obtained by melt compounding and compression molding. The biopigment dispersion in the films was improved by means of the melanin free acid treatment. It was observed that eumelanin amounts as low as 0.8 wt% caused an increase of the UV absorption, up to one order of magnitude in the UVA range. We also evaluated the effect of eumelanin on the thermal stability and photostability of the films: the biopigment proved to be double‐edged, working both as UV‐absorption enhancer and photo‐prooxidant, as thermogravimetric analysis and infrared spectroscopy revealed. © 2019 Society of Chemical Industry 相似文献