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31.
为研究沥青路面抗滑性能影响因素,精确预测路面抗滑性能,本文使用Gocator 3110三维智能传感器采集沥青混合料试件表面纹理并使用摆式摩擦仪测试试件表面摩擦系数.针对三维纹理点云数据中的异常数据,提出基于径向基函数(RBF)的邻域插值算法进行数据质量提升.根据修复后的三维纹理点云数据计算出具有代表性的10类宏观纹理特征参数,并采用Pearson系数相关性分析法去除冗余因子,改进模型的输入特征,并构建基于改进灰狼优化算法(IGWO)与XGBoost融合的沥青路面抗滑性能预测模型,预测沥青路面的摩擦系数.结果表明,提出模型的预测精度优于多元线性回归模型、支持向量机回归模型以及基于网格化搜索的XGBoost模型. 相似文献
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Maryam Shakiba Angeli Gamez Imad L. Al-Qadi Dallas Neville Little 《International Journal of Pavement Engineering》2017,18(11):1027-1038
Realistic tire–pavement interface contact areas and stresses were incorporated into the Pavement Analysis using Nonlinear Damage Approach (PANDA) user interface (PUI). PANDA is a software library developed to simulate the complex thermo-viscoelastic–viscoplastic–viscodamage responses of the pavement to mechanical and environmental loads. The PUI is an interface generating a finite element representation of the pavement within PANDA. The application of realistic tire loading is necessary to calculate accurate pavement responses. The PUI incorporates a database of tire contact areas and stresses obtained from tire finite element simulations. The database includes tire interface characteristics with pavements for various applied loads, tire inflation pressures, vehicle speeds and scenarios of different rolling simulations. A parametric study was conducted to investigate the effect of simulations of tire contact stresses that match field measurements on viscoelastic and viscoplastic pavement responses. Pavement responses are greatly affected using realistic tire loading contact stresses and contact geometry as compared to simplified contact models. The impact on rutting and damage predictions cannot be ignored if reliable projections of pavement performance are to be made. This study confirms the importance of considering realistic three-dimensional contact stresses to design and analyse pavements. 相似文献
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Javad Sadeghi E. Rajaei Najafabadi M.E. Kaboli 《International Journal of Pavement Engineering》2017,18(8):659-667
There is a lack of a profound understanding of urban pavement deterioration pattern. This is due to the complexity of traffic conditions and the variety of pavement structures in urban roads. The lack of a suitable deterioration model for the urban pavements limits the possibility of making any scientific and cost-effective repair and maintenance strategy. There is a need for a better understanding of the long-term behaviour of urban pavements by which predictive pavement condition models can be derived and consequently a suitable maintenance management system can be built. In response to this need, a comprehensive field study was performed in three Iranian cosmopolitan cities. Pervasive pavement damages were defined and an urban pavement condition index was established. A deterioration model was developed by monitoring and analysing the conditions of road pavements in a period of four years. This model varies as the structural and loading conditions of the pavement change. The efficiency and practicability of the model in predicting the conditions of the pavements were illustrated. 相似文献
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Julie M. Vandenbossche Nicole Dufalla Zichang Li 《International Journal of Pavement Engineering》2017,18(11):1004-1015
Bonded concrete overlays of asphalt pavements (BCOAs) are becoming a common rehabilitation technique used for distressed hot mix asphalt (HMA) roadways. The original design procedures were based primarily on data from instrumented pavements and finite element modelling. They were governed by the assumption that the failure mechanism was a function of the overlay thickness. However, field observations have indicated that the actual failure modes are dictated by slab size. The newly developed Bonded Concrete Overlay of Asphalt Mechanistic-Empirical design procedure (BCOA-ME) presented here is valid for overlays that are between 2.5 and 6.5 in (64–154 mm), and includes five primary enhancements to the Portland Cement Association and Colorado Department of Transportation procedures that have been traditionally used: 1.) the failure mode is dictated by the joint spacing; 2.) a new structural model for longitudinal cracking for 6-ft × 6-ft (1.8 m × 1.8 m) concrete overlays has been developed to better predict the critical stresses; 3.) the stress adjustment factors have been calibrated with performance data; 4.) the equivalent temperature gradients used as design input are defined based on the pavement structure and geographical location of the project; and 5.) the effect of temperature change on underlying HMA stiffness is considered. Finally, validation studies were completed on the new procedure and comparisons made between the revised procedure and actual performance data for five separate projects showed reasonable results. A sensitivity analysis also revealed that the predicted thickness obtained using the revised procedure was sensitive to HMA thickness, the modulus of rupture of the Portland cement concrete, and the level of traffic, as would be expected. 相似文献
36.
The primary objective of this study was to evaluate the effects of parallelogram-shaped pavement markings on vehicle speed and crashes in the vicinity of urban pedestrian crosswalks. The research team measured speed data at twelve sites, and crash data at eleven sites. Observational cross-sectional studies were conducted to identify if the effects of parallelogram-shaped pavement markings on vehicle speeds and speed violations were statistically significant. The results showed that parallelogram-shaped pavement markings significantly reduced vehicle speeds and speed violations in the vicinity of pedestrian crosswalks. More specifically, the speed reduction effects varied from 1.89 km/h to 4.41 km/h with an average of 3.79 km/h. The reduction in the 85th percentile speed varied from 0.81 km/h to 5.34 km/h with an average of 4.19 km/h. Odds ratios (OR) showed that the parallelogram-shaped pavement markings had effects of a 7.1% reduction in the mean speed and a 6.9% reduction in the 85th percentile speed at the pedestrian crosswalks. The reduction of proportion of drivers exceeding the speed limit varied from 8.64% to 14.15% with an average of 11.03%. The results of the crash data analysis suggested that the use of parallelogram-shaped pavement markings reduced both the frequency and severity of crashes at pedestrian crosswalks. The parallelogram-shaped pavement markings had a significant effect on reducing the vehicle–pedestrian crashes. Two crash prediction models were developed for vehicle–pedestrian crashes and rear-end crashes. According to the crash models, the presence of parallelogram-shaped pavement markings reduced vehicle–pedestrian crashes at pedestrian crosswalks by 24.87% with a 95% confidence interval of [10.06–30.78%]. However, the model results also showed that the presence of parallelogram-shaped pavement markings increased rear-end crashes at pedestrian crosswalks by 5.4% with a 95% confidence interval of [0–11.2%]. 相似文献
37.
钢渣沥青混凝土技术及其应用研究进展 总被引:1,自引:0,他引:1
钢渣常被当成工业废弃物处置,但其碱性强、棱角丰富,兼具有优异的力学特性,可以改善沥青混凝土的抗水损害、抗高温变形以及耐磨和抗滑等性能,被认为是可替代天然矿质集料的理想筑路材料。近年来道路建设对集料用量的高需求与天然集料短缺之间的矛盾越来越突出,钢渣沥青混凝土技术因而成为备受关注的热点。概述了钢渣的材料特性以及钢渣沥青混凝土的设计与性能,介绍了钢渣沥青混凝土的实际应用情况,研究了钢渣沥青混凝土长期应用后的路面性能变化,最后对钢渣沥青混凝土未来的发展趋势进行了展望。 相似文献
38.
采用躺滴法检测了掺加1.5%、3%的Sasobit和0.5%、1%的Evotherm 3G制备得到的温拌SBS改性沥青与蒸馏水、甘油和甲酰胺3种液体的接触角;基于表面自由能理论,对比了温拌SBS改性沥青在无水条件下的表面自由能和粘聚功以及在有水条件下的剥落功;同时,考察了温拌SBS改性沥青和石灰岩质集料的粘附功和配伍率。结果表明:采用躺滴法可以准确检测温拌SBS改性沥青与常用检测液体的接触角;以粘聚功、粘附功、剥落功、配伍率作为评价指标可用于表征温拌SBS改性沥青-集料体系的粘附性;温拌SBS改性沥青的表面自由能及其分量、粘聚功、配伍率随着Sasobit掺量的增大而减小,但随着Evotherm温拌剂掺量的增加而增大;水的参与降低了温拌剂对SBS改性沥青-集料体系粘附性影响的差异;Evotherm温拌剂有助于改善温拌SBS改性沥青的水敏感性,Sasobit温拌剂增加了温拌SBS改性沥青的水敏感性。 相似文献
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Wen Xu Kai Zhang Guangle Feng Derun Zhang 《International Journal of Pavement Engineering》2018,19(5):416-421
AbstractColoured micro-surfacing technology has become increasingly popular in pavement construction because of its economic benefit and ability to accept traffic quickly. The main goal of this study was to produce a clear asphalt with superior performance that can be easily emulsified. Two types of resin that are easy to emulsify and one kind of extract oil were used to synthesise the clear asphalt. The clear asphalt was mixed with a styrene butadiene styrene (SBS) modifier at different proportions using a mechanical agitator. The physical properties of the samples were determined via conventional bitumen tests and the optimum formula was obtained by changing the mixture ratio through orthogonal experimentation. The thin-film oven test evaluated the ageing property of the clear asphalt. The surface energy components corresponding to the advancing process and the receding process were determined using the Wilhelmy plate method. The surface free energy (SFE) of the aggregates was measured with a gravimetric sorption analyser. The adhesive bond energies between asphalt samples and aggregates were calculated using their SFE components to evaluate their properties of fracture and healing. Results show that depending on the amount and type of resin added, different synthetic clear asphalts can be obtained. Further, the clear asphalt mixed with SBS is capable of synthesising better properties at high or low temperature. The clear asphalt with aggregates had fracture and healing properties similar to common base asphalt. 相似文献