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1.
目的评估免疫细胞素Hu14.18-IL-2对黑色素瘤病人体内免疫作用。方法33位黑色素瘤病人用一种人源化抗神经节苷脂GD-2的单抗与IL-2融合的免疫细胞素进行治疗,按每天0.8、1.6、3.2、4.8、6.0、7.5 mg/m2静脉滴注,连续3 d为一疗程,病情稳定或缓解后,在第5周接受第2疗程治疗。观察病人外周血单核淋巴细胞抗体依赖的细胞毒性、自然杀伤细胞活性、IL-2的体外增殖以及IL-2可溶性受体的变化。结果Hu14.18-IL-2能诱导病人淋巴细胞的吞噬作用,增强外周血中自然杀伤细胞的杀伤能力和数目,使血清中IL-2受体复合体的可溶性受体α链水平上升。结论免疫细胞素Hu14.18-IL-2对黑色素瘤病人具有免疫激活作用。  相似文献   
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Aboveground dry biomass was estimated for the 1.3 M km2 forested area south of the treeline in the eastern Canadian province of Québec by combining data from an airborne and spaceborne LiDAR, a Landsat ETM+ land cover map, a Shuttle Radar Topographic Mission (SRTM) digital elevation model, ground inventory plots, and vegetation zone maps. Plot-level biomass was calculated using allometric relationships between tree attributes and biomass. A small footprint portable laser profiler then flew over these inventory plots to develop a generic airborne LiDAR-based biomass equation (R2 = 0.65, n = 207). The same airborne LiDAR system flew along four portions of orbits of the ICESat Geoscience Laser Altimeter System (GLAS). A square-root transformed equation was developed to predict airborne profiling LiDAR estimates of aboveground dry biomass from GLAS waveform parameters combined with an SRTM slope index (R2 = 0.59, n = 1325).Using the 104,044 quality-filtered GLAS pulses obtained during autumn 2003 from 97 orbits over the study area, we then predicted aboveground dry biomass for the main vegetation areas of Québec as well as for the entire Province south of the treeline. Including cover type covariances both within and between GLAS orbits increased standard errors of the estimates by two to five times at the vegetation zone level and as much as threefold at the provincial level. Aboveground biomass for the whole study area averaged 39.0 ± 2.2 (standard error) Mg ha? 1 and totalled 4.9 ± 0.3 Pg. Biomass distributions were 12.6% northern hardwoods, 12.6% northern mixedwood, 38.4% commercial boreal, 13% non-commercial boreal, 14.2% taiga, and 9.2% treed tundra. Non-commercial forests represented 36% of the estimated aboveground biomass, thus highlighting the importance of remote northern forests to C sequestration. This study has shown that space-based forest inventories of northern forests could be an efficient way of estimating the amount, distribution, and uncertainty of aboveground biomass and carbon stocks at large spatial scales.  相似文献   
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Reconstructing boundaries along material interfaces from volume fractions is a difficult problem, especially because the under‐resolved nature of the input data allows for many correct interpretations. Worse, algorithms widely accepted as appropriate for simulation are inappropriate for visualization. In this paper, we describe a new algorithm that is specifically intended for reconstructing material interfaces for visualization and analysis requirements. The algorithm performs well with respect to memory footprint and execution time, has desirable properties in various accuracy metrics, and also produces smooth surfaces with few artifacts, even when faced with more than two materials per cell.  相似文献   
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Light use efficiency (LUE) is an important variable characterizing plant eco-physiological functions and refers to the efficiency at which absorbed solar radiation is converted into photosynthates. The estimation of LUE at regional to global scales would be a significant advantage for global carbon cycle research. Traditional methods for canopy level LUE determination require meteorological inputs which cannot be easily obtained by remote sensing. Here we propose a new algorithm that incorporates the enhanced vegetation index (EVI) and a modified form of land surface temperature (Tm) for the estimation of monthly forest LUE based on Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. Results demonstrate that a model based on EVI × Tm parameterized from ten forest sites can provide reasonable estimates of monthly LUE for temperate and boreal forest ecosystems in North America with an R2 of 0.51 (p < 0.001) for the overall dataset. The regression coefficients (a, b) of the LUE–EVI × Tm correlation for these ten sites have been found to be closely correlated with the average EVI (EVI_ave, R2 = 0.68, p = 0.003) and the minimum land surface temperature (LST_min, R2 = 0.81, p = 0.009), providing a possible approach for model calibration. The calibrated model shows comparably good estimates of LUE for another ten independent forest ecosystems with an overall root mean square error (RMSE) of 0.055 g C per mol photosynthetically active radiation. These results are especially important for the evergreen species due to their limited variability in canopy greenness. The usefulness of this new LUE algorithm is further validated for the estimation of gross primary production (GPP) at these sites with an RMSE of 37.6 g C m? 2 month? 1 for all observations, which reflects a 28% improvement over the standard MODIS GPP products. These analyses should be helpful in the further development of ecosystem remote sensing methods and improving our understanding of the responses of various ecosystems to climate change.  相似文献   
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The objectives of an organization in combination with the formal policy together underpin the strategic direction that any organization will take. We all know that security begins with policy – in other words the rules of play. If policy is sound then the appropriate security measures can be implemented to protect the activities required to achieve the stated objectives as well as maintain the information assurance requirements – availability, integrity, authentication, confidentiality and non-repudiation.  相似文献   
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Compared the effects of signaled and unsignaled shock on the pituitary-adrenal response of 68 male Long-Evans hooded rats. In Exp I, exposure to the 2 procedures yielded no difference in plasma corticosterone levels. In Exp II, the addition of a food-reinforced leverpressing baseline produced conditioned suppression in the signaled condition but no group difference in steroid values. To guard against steroid elevations produced by exposure to shock, blood samples in Exp III were obtained during brief test sessions prior to the occurrence of shock. The procedure resulted in a significant elevation in the steroid levels of the signaled shock group. In Exp IV, a within-Ss sampling procedure revealed that disparate group steroid values obtained earlier in the session had converged by the end of the test session. The final experiment produced the original failure to obtain a steroid difference due to predictability in the absence of a behavioral baseline. Results suggest that (a) the effects of predictability are largely seen in the temporal pattern of steroid elevations and not in their terminal values, (b) the effects of predictability on steroids are modulated by the availability of control, and (c) control is not confined to the stimulus that is being predicted. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Texture mapping is a method commonly used to increase the visual complexity of computer generated images while maintaining simplicity in the underlying geometric models. Texture maps are generally defined in two dimensional space; thus, a primary problem when applying textures to objects is determining a mapping transformation from the three dimensional space of the object to the two dimensional space of the map. A method for mapping complex polygonal geometries is presented. The algorithmunfolds the object polygon by polygon and projects the texture map onto the resulting two dimensional geometry. Enhancements to the basic unfolding algorithm either (1) control the location of map distorition introduced at areas of severe curvature or (2) average distortions over a larger area.  相似文献   
9.
This paper uses four case studies to emphasize the fact that field engineering decisions cannot be made without a full understanding of all the technical problems involved. Two of the studies are taken from conventional design-bid-build projects and two are taken from design-build projects in which the ability to strongly influence design in the interest of construction efficiency places a new and increased emphasis on construction and field engineering skills. The cases also show that field engineering decisions frequently address new and unexpected realities, changed conditions, and transient loads, and thus they require high levels of understanding, technical analysis, and creative thought. We emphasize the need for universities and construction engineering programs to develop graduates who are capable of integrating design and construction considerations throughout the project delivery process. We also urge programs to continue to focus strongly on field engineering as the foundation for success in an increasingly complex and technically driven construction industry.  相似文献   
10.
Building on recent research investigating the role of life-course factors (including childhood conditions) and societal context in older Europeans health status, this study investigates the determinants of changes in elders’ health across two waves of the Survey of Health Ageing and Retirement in Europe (SHARE). Controlling for individuals’ current living conditions at baseline, our analysis provides evidence for long-term associations between childhood conditions (SES, health, cognition) and health dynamics in older age. Moreover, our findings suggest that income inequality tends to increase elders’ risk of experiencing negative health changes (decreases their chance to recover from poor health, respectively). Our study underlines the importance of accounting for both life-course and societal determinants of later life health dynamics.  相似文献   
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