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561.
PROTECTIVEEFFECTSOFCAPTOPRILANDCOENZYME Q10ONTHEMITOCHONDRIALMEMBRANE-PHOSPHOLIPIDINJURYOFYuanZuyi;,LiuZhiquan;;ZhengXiaopu,M... 相似文献
562.
用改良的荧光探针法测定外周血淋巴细胞膜流动性,此方法不需分离细胞膜,操作简便,灵敏度高,批内变异系数CV为0.9%。采用该方法对41例心力衰竭患者及20例正常人外周淋巴细胞膜流动性进行了测定,结果显示:心力衰竭患者外周淋巴细胞膜流动性P值为0.345±0.021,正常人为0.259±0.019,二者有显著差异(P<0.05);且发现外周淋巴细胞膜流动性改变与红细胞的改变一致,相关分析表明二者呈正相关(r=0.937,P<0.05)。 相似文献
563.
铁路混凝土简支梁斜截面抗剪强度的可靠度分析 总被引:1,自引:1,他引:1
本文根据型梁的抗剪试验结果及有关国内外抗剪试验数据的统计分析,并结合各个协作单位所提供的桥梁主要荷载,材料强度及几何尺寸资料,应用可靠性理论的分位值法地标准设计钢筋混凝土及预应力混凝土铁路简支梁几种跨度的笠截面抗剪度可靠指标进行了计算。分析结果表明:斜截面抗剪经度经验公式的不同,对可靠指标有定影响,但只要所建议的经验公式足够精确,这种影响是可以得到控制的。 相似文献
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Most previous works associated with transit signal priority merely focus on the optimization of signal timings, ignoring both bus speed and dwell time at bus stops. This paper presents a novel approach to optimize the holding time at bus stops, signal timings, and bus speed to provide priority to buses at isolated intersections. The objective of the proposed model is to minimize the weighted average vehicle delays of the intersection, which includes both bus delay and impact on nearby intersection traffic, ensuring that buses clear these intersections without being stopped by a red light. A set of formulations are developed to explicitly capture the interaction between bus speed, bus holding time, and transit priority signal timings. Experimental analysis is used to show that the proposed model has minimal negative impacts on general traffic and outperforms the no priority, signal priority only, and signal priority with holding control strategies (no bus speed adjustment) in terms of reducing average bus delays and stops. A sensitivity analysis further demonstrates the potential of the proposed approach to be applied to bus priority control systems in real‐time under different traffic demands, bus stop locations, and maximum speed limits. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
567.
Finding the optimal location and signal timing plan is one of the most critical operational issues for a signalized midblock crosswalk on an arterial section, which is increasingly being installed in highly populated areas in developing countries such as China. This paper presents a multiobjective optimization model and an efficient solution algorithm for a one‐ or two‐stage midblock crosswalk on an arterial section. The proposed model aims to produce the optimal location and corresponding signal settings to balance the trade‐off between pedestrian delays and vehicular bandwidth when the signals of the crosswalk and adjacent intersections are coordinated. The proposed model has three distinguishing features: (i) the costs for both pedestrians and vehicles are considered in a unified framework; (ii) the location and signal settings of the midblock crosswalk are simultaneously optimized; and (iii) a multiobjective optimization approach is developed to study the effectiveness of the midblock crosswalk under conditions in which the priorities between pedestrian and vehicle flows differ. A nondominated sorting genetic algorithm II (NSGA II)‐based algorithm is developed to solve the model efficiently. The results of the case study showed that the proposed model would help traffic practitioners, researchers, and authorities properly locate and signalize a one‐ or two‐stage midblock pedestrian crosswalk on an arterial section. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
568.
新一代江海直达船主要呈宽扁型且吃水较浅,由江入海航行时会发生船艏底部和外飘砰击,严重的砰击会造成船舶主动失速甚至结构损伤,影响船舶与人员安全。传统的理论和相关经验公式很难预报宽扁肥大的艏部结构的砰击载荷。相较于传统的简化模型试验方法,本文基于相似理论设计了与某新型江海直达船艏部结构相似的三维木质模型。采用落水试验的方法进行了一系列的不同落水高度及不同入水角度的入水砰击试验。研究江海直达船艏部结构所受砰击载荷特点,得到砰击压力峰值及其分布规律,同时发现了小角度入水情况下(入水攻角α5°)的空气垫效应,空气垫延缓并减小了砰击压力峰值。此外还回归了0°~15°入水攻角下的底部砰击压力预报公式,可供结构设计时参考砰击载荷的选取。 相似文献
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