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971.
Ni-based Mg/Al double-layered hydroxides, also called hydrotalcites (HTs), were co-precipitated with Zr (5 wt%) and impregnated with Y (0.2, 0.4, 0.6 wt%), and compared to the catalyst co-precipitated with both Y (0.4 wt%) and Zr (5 wt%). Their performance in dry reforming of methane was determined in the temperature range of 850–600 °C and stability tests at 700 °C for 5 h. The materials were characterized by X-ray powder diffraction, X-ray fluorescence, nitrogen adsorption/desorption, H2-TPR, CO2-TPD, hydrogen chemisorption, thermogravimetric analysis, transmission electron microscopy, high-resolution transmission electron microscopy, and Raman spectroscopy. A decrease in reducibility and lower total number of basic sites were observed for the sample promoted only with zirconia compared to the unpromoted material. After promotion with yttrium, no formation of ZrO2–Y2O3 solid solution was evident from XRD. The Ni dispersion was decreased due to decoration of the surface with Y species, leading to blockage of available nickel sites. All Zr and Y promoted samples were, however, more active in DRM than unpromoted HTNi. The co-precipitated Zr and Y catalyst (HTNi-ZrY0.4-cop) exhibited increasing conversion over time, and a H2/CO close to 1 in the isothermal test at 700 °C. H2-TPSR on the spent catalysts revealed that the promotion with yttrium favored regeneration of the catalytic bed, consuming the majority of removable coke and decreasing the formation of unreactive coke.  相似文献   
972.
The aim of this study was to determine the effects of ß-hydroxy-ß-methylbutyrate (HMB) supplementation during pregnancy on postpartum bone tissue quality by assessing changes in trabecular and compact bone as well as in hyaline and epiphyseal cartilage. The experiment was carried out on adult 6-month-old female spiny mice (Acomys cahirinus) divided into three groups: pregnant control (PregCont), pregnant HMB-treated (supplemented with 0.02 g/kg b.w of HMB during the second trimester of pregnancy, PregHMB), and non-pregnant females (NonPreg). Cross-sectional area and cortical index of the femoral mid-shaft, stiffness, and Young modulus were significantly greater in the PregHMB group. Whole-bone mineral density was similar in all groups, and HMB supplementation increased trabecular number. Growth plate cartilage was the thinnest, while the articular cartilage was the thickest in the PregHMB group. HMB supplementation increased the content of proteoglycans in the articular cartilage and the percentage of immature collagen content in metaphyseal trabeculae and compact bone. In summary, dietary HMB supplementation during the second trimester of pregnancy intensifies bone metabolic processes and prevents bone loss during pregnancy.  相似文献   
973.
Dr. Nicolas Boutard  Dr. Arkadiusz Białas  Dr. Aleksandra Sabiniarz  Paweł Guzik  Dr. Katarzyna Banaszak  Dr. Artur Biela  Marcin Bień  Anna Buda  Barbara Bugaj  Dr. Ewelina Cieluch  Dr. Anna Cierpich  Dr. Łukasz Dudek  Dr. Hans-Michael Eggenweiler  Dr. Joanna Fogt  Dr. Monika Gaik  Dr. Andrzej Gondela  Krzysztof Jakubiec  Dr. Mirek Jurzak  Agata Kitlińska  Dr. Piotr Kowalczyk  Maciej Kujawa  Katarzyna Kwiecińska  Marcin Leś  Dr. Ralph Lindemann  Monika Maciuszek  Maciej Mikulski  Paulina Niedziejko  Alicja Obara  Henryk Pawlik  Tomasz Rzymski  Magdalena Sieprawska-Lupa  Dr. Marta Sowińska  Joanna Szeremeta-Spisak  Agata Stachowicz  Mateusz M. Tomczyk  Dr. Katarzyna Wiklik  Łukasz Włoszczak  Sylwia Ziemiańska  Dr. Adrian Zarębski  Dr. Krzysztof Brzózka  Dr. Mateusz Nowak  Dr. Charles-Henry Fabritius 《ChemMedChem》2019,14(1):169-181
Energy and biomass production in cancer cells are largely supported by aerobic glycolysis in what is called the Warburg effect. The process is regulated by key enzymes, among which phosphofructokinase PFK-2 plays a significant role by producing fructose-2,6-biphosphate; the most potent activator of the glycolysis rate-limiting step performed by phosphofructokinase PFK-1. Herein, the synthesis, biological evaluation and structure–activity relationship of novel inhibitors of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), which is the ubiquitous and hypoxia-induced isoform of PFK-2, are reported. X-ray crystallography and docking were instrumental in the design and optimisation of a series of N-aryl 6-aminoquinoxalines. The most potent representative, N-(4-methanesulfonylpyridin-3-yl)-8-(3-methyl-1-benzothiophen-5-yl)quinoxalin-6-amine, displayed an IC50 of 14 nm for the target and an IC50 of 0.49 μm for fructose-2,6-biphosphate production in human colon carcinoma HCT116 cells. This work provides a new entry in the field of PFKFB3 inhibitors with potential for development in oncology.  相似文献   
974.
The development of a new parallel framework for integrated modeling of tokamak plasmas is a primary objective of the SciDAC Framework Architecture for Core-Edge Transport Simulations (FACETS) project. The FACETS code will be used to predict the performance of tokamak discharges and to optimize tokamak discharge scenarios. Novel parallel numerical algorithms and solvers have been developed in the FACETS project in order to simulate the multi-scale dynamics of tokamak plasmas. The status of development of modules for anomalous transport in the FACETS code is described in this paper. Mechanisms that are used for coupling 1D anomalous transport in the plasma core together with 2D transport in the plasma edge (in near separatrix and scrape-off-layer regions) are considered. Results of the first verification studies based on predictive modeling of several analytical and experimental equilibria are presented.  相似文献   
975.
The Streptococcus pyogenes Cas9 protein (SpCas9), a component of CRISPR-based immune system in microbes, has become commonly utilized for genome editing. This nuclease forms a ribonucleoprotein (RNP) complex with guide RNA (gRNA) which induces Cas9 structural changes and triggers its cleavage activity. Here, electronic circular dichroism (ECD) spectroscopy was used to confirm the RNP formation and to determine its individual components. The ECD spectra had characteristic features differentiating Cas9 and gRNA, the former showed a negative/positive profile with maxima located at 221, 209 and 196 nm, while the latter revealed positive/negative/positive/negative pattern with bands observed at 266, 242, 222 and 209 nm, respectively. For the first time, the experimental ECD spectrum of the gRNA:Cas9 RNP complex is presented. It exhibits a bisignate positive/negative ECD couplet with maxima at 273 and 235 nm, and it differs significantly from individual spectrum of each RNP components. Additionally, the Cas9 protein and RNP complex retained biological activity after ECD measurements and they were able to bind and cleave DNA in vitro. Hence, we conclude that ECD spectroscopy can be considered as a quick and non-destructive method of monitoring conformational changes of the Cas9 protein as a result of Cas9 and gRNA interaction, and identification of the gRNA:Cas9 RNP complex.  相似文献   
976.
977.
Reticulated polyurethane foams are often used as templates for the processing of metal and ceramic foams, since polyurethane foams with a high homogeneity and uniformity of pores and a wide variety of porosities and pore sizes are commercially available. Current conventional methods to pyrolyse polyurethane have brought attention to issues such as long processing time, high costs and high contents of carbon residue. Microwave hybrid heating, as a new pyrolysis method, has been investigated in this research to overcome these issues. Two microwave hybrid and one conventional heating process as comparison were performed to pyrolyse binder and polyurethane for the processing of NiCr8020 foams, which were fabricated by dip-coating method in a powder metallurgical route. Compared to the conventional process, the processing time and residual carbon content of the pyrolysed and pre-sintered foams can be reduced significantly by utilizing microwave hybrid heating techniques, whereas the stability of microwave hybrid heating must be improved and a compromise must be made between the heating rate and the residual carbon content due to the formation of burst holes during the rapid decomposition of polyurethane.  相似文献   
978.
979.
The aim of this work is to evaluate analytical tools for fast assessment of the catalysts’ ability to conduct a catalytic cracking process with the use of vegetable oils. The practical context of the presented concept relates to the use of cracking reaction products as valuable chemical raw materials. The proposed analytical tools allow for quick assessment of reaction products, indication of the molecular weight range, or the presence of specific functional groups. We want to emphasize that vegetable oils can not only be raw products for biofuels but also an alternative to petrochemicals. The study was undertaken to determine the influence of acid–base properties of catalysts on the rapeseed oil conversion process at 500°C. The effect of these properties on the character of the process and quality of the products obtained was shown to be very high. Basic correlations between the formation of coke, gaseous products and dehydrogenation products, and acid–base parameters of the individual catalysts have been observed. The use of spectroscopic methods (FTIR - Fourier Transform Infrared Spectroscopy, 1H NMR - Nuclear Magnetic Resonance) for fast qualitative analysis of the products is described.  相似文献   
980.
A food that has been praised for its beneficial effects on overall health is fish, particularly its polyunsaturated n-3 fatty acids, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). However, it has recently been suggested that minor fatty acids such as furan fatty acids are needed in combination with DHA and EPA to exert these positive effects of fish and fish oils. Only recently have furan fatty acids become available in quantities that allow the investigation of their biofunctional properties. In this study, the uptake and effect of the furan fatty acid 9-(3-methyl-5-pentylfuran-2-yl)-nonanoic acid (9M5) as a sole component and in combination with DHA and EPA on adipogenesis were analyzed using the 3T3-L1 cell model. 9M5 is taken up and metabolized into 7M5, 5M5, and 3M5 in 3T3-L1 adipocytes during a 24-h period as shown with gas chromatography with mass spectrometry (GC/MS). Furthermore, 9M5 significantly increased lipid accumulation during the differentiation process of 3T3-L1 preadipocytes into adipocytes. In addition, the combinations of DHA + 9M5 and EPA + DHA + 9M5 also exerted a significant increase compared to control adipocytes. 3T3-L1 cells incubated with 9M5 resulted in an increased protein expression of PPARγ, C/EBPα, FABP4, and adiponectin, although not to the extent that DHA as a sole component or DHA + 9M5 did. Earlier studies have shown that DHA is a natural ligand for PPARγ, thus being a potential alternative to the antidiabetic thiazolidinediones. We show that 9M5 activates a PPARγ-responsive reporter gene and could therefore be a natural ligand for PPARγ.  相似文献   
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