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排序方式: 共有209条查询结果,搜索用时 15 毫秒
61.
Ilias G. Kavouras Vicken Etyemezian David W. DuBois 《Environmental Modelling & Software》2009,24(8):1003-1011
Soil properties and air-mass backward trajectories were integrated into a geographical information systems (GIS) tool to identify geographical regions that were likely to have significant influence on dust concentrations at Class I national parks and wilderness areas in US. The Windblown Dust Index (WDI) was introduced by spatial analysis of wind erosion and land use/land cover data for North America to identify potential area sources of windblown dust. The spatial probability density maps of backward trajectories were utilized to determine the number of trajectory points that passed near a grid cell at speeds higher than a specified threshold value. Analysis of data for the Salt Creek and White Mountain wilderness areas highlighted the significant potential of both local and regional sources of windblown dust at the two sites, with evidence for seasonal variation. These data are useful in evaluating the importance of windblown dust source areas and developing cost-effective targeted studies and/or mitigation strategies. 相似文献
62.
Charalampos Doukas Ilias Maglogiannis 《IEEE engineering in medicine and biology magazine》2007,26(5):29-35
We have provided an overview of state-of-the-art ROI coding techniques applied to medical images. These techniques are classified according to the image type they apply to; thus the first class includes ROI coding schemes developed for two-dimensional (2-D) still medical images whereas the second class consists of ROI coding in the case of volumetric images. In the third class, a prototype ROI encoder for compression of angiogram video sequences is presented. ROI coding preserves image quality in diagnostically critical regions by performing advanced image compression, enabling better image examination and addressing issues regarding image handling and transmission in telemedicine systems. The mapping of the ROI from the spatial domain to the wavelet domain is dependent on the used wavelet filters and it is simplified for rectangular and circular regions. Therefore, ROI coding is considered quite important in distributed and networked electronic healthcare. 相似文献
63.
A promising anode material for hybrid electric vehicles (HEVs) is Li4Ti5O12 (LTO). LTO intercalates lithium at a voltage of ∼1.5 V relative to lithium metal, and thus this material has a lower energy compared to a graphite anode for a given cathode material. However, LTO has promising safety and cycle life characteristics relative to graphite anodes. Herein, we describe electrochemical and safety characterizations of LTO and graphite anodes paired with LiMn2O4 cathodes in pouch cells. The LTO anode outperformed graphite with regards to capacity retention on extended cycling, pulsing impedance, and calendar life and was found to be more stable to thermal abuse from analysis of gases generated at elevated temperatures and calorimetric data. The safety, calendar life, and pulsing performance of LTO make it an attractive alternative to graphite for high power automotive applications, in particular when paired with LiMn2O4 cathode materials. 相似文献
64.
Ilias Marmouzi Nezha Saidi Bouchra Meddah Mohammed Bouksaim Said Gharby Miloud El Karbane Samira Serragui Yahia Cherrah My El Abbes Faouzi 《Sensing and Instrumentation for Food Quality and Safety》2016,10(1):156-165
Oat has been recognized as a healthy food for a long time. In this study, physicochemical analysis including, moisture, pH, ash, fibres, proteins, starch, carbohydrates, some minerals, sugars, fatty acids, sterols, total phenolic, and flavonoid contents of four Moroccan Oat varieties (Amlal, Tissir, Zahri and Ghali) were investigated. Additionally, starch morphology has been described according to scanning electron microscopy, and viscosity as measured on a rotary rheometer, increased with stabilization time. Furthermore, Oat extracts were analyzed with regard to their antioxidant activities using DPPH radicals’ cation, Trolox equivalent antioxidant capacity and ferric reducing/antioxidant power. Results from this investigation demonstrated that Moroccan Oat varieties constitute an interesting supplement of natural antioxidants, especially phenolic compounds. Moreover, potassium was the main mineral in Oat seeds (1628.17–2541.52 mg/Kg); also, the oleic, linoleic, and palmitic acids were the dominant fatty acids. While the major sterols were, β-sitosterol, Δ-5-avenasterol and campesterol. Finally, sugar analysis by HPLC-RI indicate that sucrose content was higher than glucose and fructose respectively, and that Ghali and Amlal varieties exhibit an important total sugars levels. Those results highlight the possible contributions of Oat seeds to nutritional therapy. 相似文献
65.
Ilias K. Nikolaidis Ioannis G. Economou Georgios C. Boulougouris Loukas D. Peristeras 《American Institute of Chemical Engineers》2016,62(3):868-879
A robust numerical scheme for the calculation of constant composition (isoplethic) phase diagrams of complex multicomponent mixtures is presented. The scheme refers to the sequential calculation of the phase envelope of a mixture by guiding the estimation for the equilibrium curve via the introduction of a “spring” that sets the slope value of the modified tangent plane distance with respect to either temperature or pressure. A simple variation of the proposed method allows direct estimation of the Cricondentherm and/or Cricondenbar points, thus avoiding the calculation of the entire phase diagram. Extensive tests of the proposed scheme for different types of phase diagrams, using both cubic and higher‐order equations of state are presented. © 2015 American Institute of Chemical Engineers AIChE J, 62: 868–879, 2016 相似文献
66.
We present a computational approach to the design of fiscal policy that is based on algorithmic, linear feedback control methods. In particular, in the context of a linear, deterministic macro-model, we develop an algorithmic procedure which allows us to design fiscal policy rules for government expenditures so that desired target-levels for GDP are exactly met (that is, complete tracking is achieved). In order to examine the effectiveness of our method we estimate the model for the Greek economy and run some counterfactual policy experiments. These experiments indicate that, for the Greek economy in the beginning of the crisis in early 2010, expansionary fiscal policy would have been able to stimulate growth and reduce the debt-to-GDP ratio. 相似文献
67.
Effect of pre-heating duration and temperature conditioning on the rheological properties of bitumen
Samer Dessouky Christopher Reyes Mohammed Ilias David Contreras A.T. Papagiannakis 《Construction and Building Materials》2011,25(6):2785-2792
It is well known that overheating asphalt bitumen can lead to oxidation and stiffening. While heating bitumen is an essential protocol in sample preparation, it is important to identify the oven setting time and temperature for lab testing. Current AASHTO standards do not specify exact oven settings for bitumen sample preparation prior to laboratory testing. This study is evaluating the effect of oven heating duration and pouring temperature during sample preparation in the rheological properties of neat and polymer-modified bitumen (PMB). Rheological properties are measured using Rotational Viscometer, Dynamic Shear Rheometer and Bending Beam Rheometer at grade-specific testing temperatures. A neat bitumen PG64-22 and two PMB PG70-22 and 76-22 in un-aged (original) and aged conditions were tested at two temperatures: 143 °C and 185 °C for 1/2, 2 and 4 h. The effect of short-term aging by rolling thin film oven was also investigated. To investigate the rheological properties over a wide range of temperatures, temperature sweep testing was conducted from 35 °C to 110 °C at a 10 rad/s frequency. The results suggest that there was no significant difference in the viscosity, complex modulus and creep stiffness for the tested bitumen. The RTFO aging index, absolute drop of complex viscosity and temperature aging indices were used to evaluate the bitumen preparation settings. The study recommends using the 143 °C and 2-h heating for proper preparation prior to standard lab testing. The study also investigated the aging influence in rheological properties for neat and PMB using the black diagram, DSR function map, and critical-stiffness temperature. 相似文献
68.
69.
Stefania Maniatsi Ilias Kappas Athanasios D. Baxevanis Theodora Farmaki Theodore J. Abatzopoulos 《International journal of molecular sciences》2009,10(12):5455-5470
Genealogical concordance is a critical overlay of all phylogenetic analyses, irrespective of taxonomic level. To assess such patterns of congruence we have compiled and derived sequence data for two mitochondrial (16S rRNA, COI) and two nuclear (ITS1, p26) markers in 14 American populations of the hypersaline branchiopod Artemia franciscana. Cladistic analysis revealed three reciprocally monophyletic mitochondrial clades. For nuclear DNA, incomplete lineage sorting was evident presumably as a result of slower coalescence or male-mediated dispersal. Our findings capture the genealogical interval between gene splitting and population divergence. In this sense, strong indications are provided in favour of a superspecies status and ongoing speciation in A. franciscana. 相似文献
70.