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排序方式: 共有1561条查询结果,搜索用时 31 毫秒
1.
基于抑制交通流不稳定性所需的条件,分析司机后视获得的最相邻后车综合信息对交通流不稳定性的影响. 在司机关注前车信息概率大于关注后车信息概率与司机敏感系数大于0的现实条件下,解析分析以及仿真分析得到了以下结论:1)最相邻后车车头距信息减小了交通流的不稳定性,且关注概率越大,减小作用越大;跟驰车与最相邻后车的速度差信息增加了交通流的不稳定性,且关注概率越大,增加作用越大. 2)最相邻后车综合信息对交通流的不稳定性的减小作用大于增加作用,即最相邻后车综合信息减小了交通流的不稳定性. 3)司机距离差敏感系数越大,最相邻后车综合信息对交通流的不稳定性减小作用越大. 4)司机速度差敏感系数越大,最相邻后车综合信息对交通流的不稳定性增加作用越大.
关键词:
交通堵塞
交通流不稳定性
最相邻后车综合信息
跟驰模型 相似文献
2.
Effect of Cr,Mo, and Nb additions on intergranular cohesion of ferritic stainless steel: First-principles determination 下载免费PDF全文
Effects of Cr, Mo, and Nb on the ferritic stainless steel ]2(210) grain boundary and intragranularity are investigated using the first-principles principle. Different positions of solute atoms are considered. Structural stability is lowered by Cr doping and enhanced by Mo and Nb doping. A ranking on the effect of solute atoms enhancing the cohesive strength of the grain boundary, from the strongest to the weakest is Cr, Mo, and Nb. Cr clearly prefers to locate in the intragranular region of Fe rather than in the grain boundary, while Mo and Nb tend to segregate to the grain boundary. Solute Mo and Nb atoms possess a strong driving force for segregation to the grain boundary from the intragranular region, which increases the grain boundary embrittlement. For Mo- and Nb-doped systems, a remarkable quantity of electrons accumulate in the region close to Mo (Nb). Therefore, the bond strength may increase. With Cr, Mo, and Nb additions, an anti-parallel island is formed around the center of the grain boundary. 相似文献
3.
高速道岔转换时需要采用多转辙机牵引,详细给出了便携式多转辙机牵引道岔转换阻力测试仪的设计过程;该测试仪以NXP公司的ARM7微处理器LPC2214为硬件核心,以uC/OS-II实时操作系统为软件核心,测试仪主机和各传感器采用树形拓扑结构的主从机方案,使用单芯电缆传输技术,将测试仪主机与各传感器联接到一起,完成的同时对1~6台在轨转辙机的牵引力的测量和为各传感器供电;实测表明,测试仪完全满足设计要求,适合铁路电务人员对多点多转辙机牵引道岔转换阻力进行在轨测量,满足实际要求。 相似文献
4.
本文以右转机动车和直行自行车为对象研究交叉口混合交通流特性.基于交叉口机非干扰特性,将机动车元胞模型和自行车元胞模型进行了耦合,建立了考虑自行车穿越机动车延时、机动车穿越自行车间隙和冲突区占据处置等规则的交叉口混合交通流元胞自动机模型(NS-BCA).对右转机动车与直行自行车混合交通流进行了仿真,从流量-车辆到达率关系、交通流相位相变、交通流相位-到达率-混合交通流状态等方面研究了交叉口混合交通流的机非干扰机理. 相似文献
5.
We present the first complete data set for the permeability, diffusivity, and solubility of both deuterium and hydrogen in 316L stainless steel (316L SS) obtained over a wide temperature range of 350–850 °C that accommodates both nuclear fusion and nuclear hydrogen technology applications. The deuterium results were also compared with the hydrogen results to estimate the isotope effect. The isotope effect ratio for diffusivity was different from the classical prediction. Furthermore, some of our results were compared with the results previously reported for 316 SS. Results and discussion are presented with an emphasis on the deuterium permeation and isotope effects. 相似文献
6.
A new active infrared thermography based technique is proposed for defect detection in ferromagnetic specimens using a low frequency alternating magnetic field induced heating. The test specimens (four mild steel specimens with artificial rectangular slots of 8.0, 5.0, 3.3 and 3.0 mm depths) are magnetized using a low frequency alternating magnetic field and by using an infrared camera, the surface temperature is remotely monitored in real time. An alternating magnetic field induces an eddy current in the specimen which increases the specimen temperature due to the Joule’s heating. The experimental results show a thermal contrast in the defective region that decays exponentially with the defect depth. The observed thermal contrast is attributed to the reduction in induction heating due to the leakage of magnetic flux caused by magnetic permeability gradient in the defective region. The proposed technique is suitable for rapid non-contact wide area inspection of ferromagnetic materials and offers several advantages over the conventional active thermography techniques like fast direct heating, no frequency optimization, no dependence on the surface absorption coefficient and penetration depth. 相似文献
7.
In the Distance Constrained Multiple Vehicle Traveling Purchaser Problem (DC-MVTPP) a fleet of vehicles is available to visit suppliers offering products at different prices and with different quantity availabilities. The DC-MVTPP consists in selecting a subset of suppliers so to satisfy products demand at the minimum traveling and purchasing costs, while ensuring that the distance traveled by each vehicle does not exceed a predefined upper bound. The problem generalizes the classical Traveling Purchaser Problem (TPP) and adds new realistic features to the decision problem. In this paper we present different mathematical programming formulations for the problem. A branch-and-price algorithm is also proposed to solve a set partitioning formulation where columns represent feasible routes for the vehicles. At each node of the branch-and-bound tree, the linear relaxation of the set partitioning formulation, augmented by the branching constraints, is solved through column generation. The pricing problem is solved using dynamic programming. A set of instances has been derived from benchmark instances for the asymmetric TPP. Instances with up to 100 suppliers and 200 products have been solved to optimality. 相似文献
8.
罗金炎 《数学的实践与认识》2014,(23)
设计了一种改进的二进制粒子群优化算法来求解车辆路径问题,算法基于粒子群算法的寻优模式充分考虑粒子之间的导向作用,改进二进制粒子群算法的位取值方式,减小了在进化过程中停滞于局部最优解的概率,并通过构造辅助函数处理优化问题的约束条件,基于分层次实现多个目标的思路来寻优,提高了算法的搜索效率和计算速度.实验测试结果验证了该算法对求解车辆路径问题的适用性和有效性. 相似文献
9.
《Arabian Journal of Chemistry》2014,7(3):319-326
The efficiency of three furan derivatives, namely 2-(p-toluidinylmethyl)-5-methyl furan (Inh. A), 2-(p-toluidinylmethyl)-5-nitro furan (Inh. B) and 2-(p-toluidinylmethyl)-5-bromo furan (Inh. C), as possible corrosion inhibitors for mild steel in 1.0 M HCl, has been determined by weight loss and electrochemical measurements. These compounds inhibit corrosion even at very low concentrations, and 2-(p-toluidinylmethyl)-5-methyl furan (Inh. A) is the best inhibitor. Polarization curves indicate that all compounds are mixed-type inhibitors, affecting both cathodic and anodic corrosion currents. Adsorption of furan derivatives on the mild steel surface follows the Langmuir adsorption isotherm, and the calculated Gibbs free energy values confirm the chemical nature of the adsorption. Monte Carlo simulations technique incorporating molecular mechanics and molecular dynamics can be used to simulate the adsorption of furan derivatives on mild steel surface in 1.0 M HCl. 相似文献
10.
高速工具钢为高碳高合金工具钢,常温下样品酸溶分解较为困难,因此建立了微波消解电感耦合等离子体原子发射光谱法(ICP-AES)测定高速工具钢中锰、磷、镍、铜、铬、钒的方法,利用微波消解提高溶样的温度和压力,在王水、氢氟酸和硫酸介质中使样品充分消解,再用饱和硼酸溶液络合过量的氢氟酸,基体匹配消除铁基体的影响,ICP-AES法同时测定锰、磷、镍、铜、铬、钒的含量。测定高速工具钢标准样品,测定值与标样值相吻合,方法的相对标准偏差在0.55%~4.1%。加标回收率在95.6%~114.8%,满足测定要求。 相似文献