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31.
Bernard K Tarabalka Y Angulo J Chanussot J Benediktsson JA 《IEEE transactions on image processing》2012,21(4):2008-2021
In this paper, a new method for supervised hyperspectral data classification is proposed. In particular, the notion of stochastic minimum spanning forest (MSF) is introduced. For a given hyperspectral image, a pixelwise classification is first performed. From this classification map, M marker maps are generated by randomly selecting pixels and labeling them as markers for the construction of MSFs. The next step consists in building an MSF from each of the M marker maps. Finally, all the M realizations are aggregated with a maximum vote decision rule in order to build the final classification map. The proposed method is tested on three different data sets of hyperspectral airborne images with different resolutions and contexts. The influences of the number of markers and of the number of realizations M on the results are investigated in experiments. The performance of the proposed method is compared to several classification techniques (both pixelwise and spectral-spatial) using standard quantitative criteria and visual qualitative evaluation. 相似文献
32.
Jose M. Algueta Antonio J. Lopez‐Martin Jaime Ramirez‐Angulo Ramon G. Carvajal 《International Journal of Circuit Theory and Applications》2014,42(8):831-841
A technique to improve the input and output range of CMOS transconductors with resistive current division for continuous tuning is presented. Using it, a tunable transconductor is proposed which features high linearity over a wide input range and simplicity. Measurement results of the transconductor, fabricated in a 0.5 µm CMOS process, show an IM3 of ?66 dB for a ±1.65 V supply and two input tones centered at 1 MHz of 1 Vpp each, and only 0.7 mW of power consumption. This represents an improvement of 13 dB versus the same transconductor using conventional current division. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
33.
Recent studies on the use of vegetable fibers in polymers have led to the conclusion that the fibers must be treated to improve their adherence to plastic matrices. The present study investigated the effect of physical and chemical treatments on the suitability of fiber from the Canary banana tree for use as reinforcement for polymers in injection molding processes. This fiber has the advantage of being derived from the vegetable waste that is produced by farms involved in banana cultivation in the Canary Islands. Sodium hydroxide and maleic anhydride were used to treat the fiber under different conditions of pressure and temperature, and then the fiber was examined by thermogravimetric analysis and Fourier transform infrared spectroscopy. The best treatment for improving the thermal properties of banana fiber, with no significant decrease in mechanical behavior, for use in a composite was a combination of 1 N NaOH and saturation pressure. 相似文献
34.
Roberto Cannataro Leandro Carbone Jorge L. Petro Erika Cione Salvador Vargas Heidy Angulo Diego A. Forero Adrin Odriozola-Martínez Richard B. Kreider Diego A. Bonilla 《International journal of molecular sciences》2021,22(18)
Sarcopenia, an age-related decline in skeletal muscle mass and function, dramatically affects the quality of life. Although there is a consensus that sarcopenia is a multifactorial syndrome, the etiology and underlying mechanisms are not yet delineated. Moreover, research about nutritional interventions to prevent the development of sarcopenia is mainly focused on the amount and quality of protein intake. The impact of several nutrition strategies that consider timing of food intake, anti-inflammatory nutrients, metabolic control, and the role of mitochondrial function on the progression of sarcopenia is not fully understood. This narrative review summarizes the metabolic background of this phenomenon and proposes an integral nutritional approach (including dietary supplements such as creatine monohydrate) to target potential molecular pathways that may affect reduce or ameliorate the adverse effects of sarcopenia. Lastly, miRNAs, in particular those produced by skeletal muscle (MyomiR), might represent a valid tool to evaluate sarcopenia progression as a potential rapid and early biomarker for diagnosis and characterization. 相似文献
35.
Foodborne diseases are an important public problem affecting millions of Americans each year and resulting in substantial morbidity and mortality. Many foodborne infections occur in outbreak settings. Outbreaks are often detected by complaints from the public to health authorities. This report reviews complaints received by the San Francisco Department of Public Health involving suspected foodborne illness in 1998. Although such foodborne complaints are commonly received by health officials, we provide the first review of population-based data describing such complaints. We use a broad definition of a foodborne disease outbreak. We judged a complaint to be a "likely foodborne disease outbreak" if it involved more than one person and more than one family; no other common meals were shared recently by ill persons; diarrhea, vomiting, or both was reported; and the incubation period was more than one hour. In 1998, 326 complaints of foodborne illness, involving a total of 599 ill people, were received by the Communicable Disease Control Unit in San Francisco. The complaints involved from 1 to 36 ill persons, with 61% involving one ill person and 25% involving two ill persons. Of the 126 reports involving illness in more than one person, 77 (61%) were judged to be likely foodborne disease outbreaks. Three of these 77 outbreaks had been investigated prior to our review. This project confirms that more foodborne disease outbreaks occur than are reported to state and national outbreak surveillance systems. Our review of the San Francisco system highlights opportunities for gleaning valuable information from the foodborne disease complaint systems in place in most jurisdictions. 相似文献
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38.
C Peiró J Angulo JL Llergo L Rodríguez-Ma?as J Marín CF Sánchez-Ferrer 《Canadian Metallurgical Quarterly》1997,240(2):367-371
Matrix metalloproteinases (MMP) are enzymes responsible for extracellular matrix degradation, a critical component influencing the growth and metastatic potential of cancer. The purpose of this study was to determine the in vitro effects of MMP inhibition on human pancreatic cancer cells and to document its effect on cancer growth in vivo. The effect of MMP inhibition was determined using the MMP inhibitor BB-94 and a moderately differentiated pancreatic cancer cell line (HPAC). In vitro, a dose response curve was generated over 5 days utilizing the MTT [3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. In vivo, using an established orthotopic model for pancreatic cancer (LD100 = 80 days), 22 nude mice with orthotopic tumors (30 were implanted) received either BB-94 or vehicle beginning 4 days prior to implantation and continuing to death or sacrifice on Day 70. Mice were weighted weekly. At death/sacrifice, tumors were weighted, volume determined, and metastases/ distant spread documented. In vitro, BB-94 had little effect on HPAC proliferation at 40 ng/ml but achieved progressively greater to near complete inhibition at doses up to 4000 ng/ml while maintaining cell viability. In vivo, BB-94 significantly increased length of survival (69 +/- 0.1 days vs. 56 +/- 3.1 days) and necropsy weight (25.7 +/- 1.67 g vs. 19.8 +/- 1.14 g) while decreasing metastatic rate (1 vs. 20) and tumor size (0.14 +/- 0.02 g vs. 0.65 +/- 0.1 g). MMP inhibition limits HPAC proliferation in a dose-dependent fashion without direct cytotoxic effects in vitro. Mice harboring orthotopic tumors treated with BB-94 demonstrated significant reductions in tumor weight, volume, and metastases which corresponded to increased animal weight and prolonged survival. 相似文献
39.
Lopez S. de la Vega D. Angulo I. Guerra D. Angueira P. Arrinda A. Ordiales J.L. 《Electronics letters》2008,44(22):1286-1288
Recently developed digital radio systems for the medium wave band require accurate field strength prediction algorithms for coverage estimation. Presented is a comparison of estimation accuracy provided by the most relevant field strength prediction methods employed for ground-wave propagation at this band. Moreover, a field strength prediction method recently developed by the authors, has been considered in the analysis. Empirical values from measurement campaigns carried out in three different broadcasting networks have been used to analyse the accuracy of the prediction methods. Comparison between predicted and measured values allows objective evaluation of the estimation accuracy of each method under different reception conditions. The proposed method provides the most accurate results on field strength predictions, consequently it is a suitable method for the coverage estimation of the new digital radio systems. 相似文献
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