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51.
Xiaoliang Li Yi Gao Jiawen Liu Xin Yu Zhonghua Li 《International Journal of Hydrogen Energy》2017,42(18):13031-13038
We successfully synthesized novel Ti3+ doped TiO2 and Ti3+ doped Ag/AgITiO2 nanoparticles with efficient visible-light photocatalytic activity for hydrogen production by facile one-step solvothermal method. The as-prepared Ti3+ doped TiO2 nanoparticles displayed excellent visible-light absorption and visible-light driven hydrogen production activity (115.3 μmol g?1 h?1), while the commercial TiO2 had no visible-light response. Moreover, the as-prepared Ti3+ doped Ag/AgITiO2 nanoparticles in this experiment showed highly enhanced visible-light absorption and efficient visible-light driven activity for hydrogen (571.0 μmol g?1 h?1), which was 4.95 times as high as that of the as-prepared TiO2 nanoparticles. And the surface areas of the as-prepared TiO2 and Ti3+ doped Ag/AgITiO2 catalysts were up to 138.829 m2 g?1 and 102.988 m2 g?1, much higher than that of the commercial TiO2 (55.516 m2 g?1). Finally, the visible-light photocatalytic mechanism of the Ti3+ doped Ag/AgITiO2 nanoparticles for hydrogen generation was also proposed in detail. 相似文献
52.
针对几种经典算法的效率问题,提出了一种最近点对求解算法:算法预先找到X、Y坐标轴最大、最小坐标值,将点集按某坐标轴排序,并根据鸽巢原理计算最近点对i间距离的上限,由此上限将整个点集分割成不同的区域,最后在每个区域中通过动态缩小每个点的矩形窗减少了算法的计算次数.通过理论证明和实际验证得出:初始点集有序时算法的时间复杂度为O(n);无序时在一般情况下为O(n),最坏情况下为O(nlogn);算法的时间复杂度和运行时间明显优于经典分治算法和基于底函数的算法. 相似文献
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上下回流人工湿地预处理微污染水库水的研究 总被引:1,自引:0,他引:1
采用上下回流潜流人工湿地对微污染水库水进行预处理试验。根据试验数据,构建了上下回流潜流人工湿地系统CODCr、TN、TP的一级动力学模拟方程。结果表明:在水力负荷为0.4m3/(m2.d)条件下,CODCr、TN、NH3-N、TP的平均去除率均分别达到56.06%、58.97%、55.91%和50.56%。湿地系统夏季处理效果明显好于其他季节。使用周期按20年考虑,日均进水量3.6m3/d,湿地建设成本为2100元,水的处理成本为0.13元/m3,这表明采用人工湿地预处理微污染水库水是经济可行的。 相似文献
55.
The effects of Humic Acid (HA) concentration,pH value and aeration on the photocatalysis degradation of HA by the silica gel supported TiO2 were studied.Moreover,the effect of aeration on the generation of hydroxyl radicals are investigated.The experimental results indicated that the hydroxyl radicals are generated during the photocatalysis process.The generation of hydroxyl radicals is increasing linearly with the reaction time,approximately.Moreover,the generation rate of hydroxyl under the condition of aeration is 1.57 times of that under the condition without aeration,which is the main influent factor on the reaction rate.Therefore,the reaction rate constant with and without aeration is 0.012 min-1 and 0.0063 min-1,respectively.The degradation rate decreases when the initial HA concentration increases,which is due to that more TiO2 active sites are occupied by HA when the HA concentration is higher.Moreover,HA can absorb large amount of photons,which can prevent those available photons to arrive at the activate TiO2 particles.The degradation rate decreases when increasing pH value,which is due to that the adsorption of HA on the TiO2 particles is weakened and not benefit for the degradation process of HA. 相似文献
56.
为克服粒子群算法容易陷入局部最优和全局寻优精度不高的缺点,通过对算法的局部寻优和全局寻优的特点进行分析,首先使用正态分布衰减策略改进惯性权重;同时基于算法运行的时间自适应采用不同的基于高斯分布及柯西分布的变异优化策略,解决全局搜索和局部开发能力的不平衡问题,实现了局部寻优和全局寻优的双重优化,满足了提高寻优速度和寻优精... 相似文献
57.
采用化学镀铜的方法对增强相碳纳米管(CNTs)和Ti3AlC2进行表面改性,热压烧结制备了CNTs-Ti3AlC2/AZ91D复合材料,研究了其微观组织和力学性能的变化及增强机制。结果表明:CNTs-Ti3AlC2/AZ91D复合材料内部主要物相为CNTs、Ti3AlC2、Mg和Al12Mg17,增强相均匀分布在基体内,在增强相与基体的界面处存在U相(MgAlCu),使二者界面结合良好。当增强相CNTs 和Ti3AlC2含量分别为1wt%和25wt%时,较镁合金AZ91D,CNTs-Ti3AlC2/AZ91D复合材料的弹性模量、拉伸强度、屈服强度和延伸率分别提高了120.30%、25.72%、126.50%和36.84%,弯曲强度和压缩强度分别为337.92 MPa和436.27 MPa。CNTs-Ti3AlC2/AZ91D复合材料的断裂方式表现为脆性断裂,其强化机制主要为热配错强化、Orowan强化和细晶强化机制。 相似文献
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59.
《Ceramics International》2016,42(12):13535-13546
We report the morphology-controlled ZnO nanostructures (ZNSs) evolution synthesized via a novel and facile technique at different growth times, where the pulse laser ablation in liquid (PLAL) is creatively combined with hydrothermal (H) method (hereafter called PLAL-H technique). Four types of ZNSs with varying sizes and shapes such as tapers, multipods, flowers, and hollow flowers are produced on Si substrate via PLAL-H technique. Furthermore, multipod- and flower-like ZNSs are grown using direct hydrothermal method to compare them with the one obtained via synergistic effects of PLAL-H method. This catalyst-free fabrication method is not only cost-effective but greatly useful for the rapid production of different quality of ZNSs at low temperature. ZNSs synthesized under prolonged growth time (60 min) exhibited structural deformation. Growth technique and time dependent morphology, structure, composition, and optical properties of these as-grown ZNSs are characterized using FESEM, X-ray diffraction, FTIR, photoluminescence, and UV–vis measurements. Synthesized ZNSs revealed excellent crystallinity and growth process dependent variation in the physical and optical features. The ZNSs growth mechanism is understood. Excellent features of the results demonstrate that this synergized new growth technique may constitute a basis for modifying the morphology, sizes, and optical properties of ZNSs in a controllable manner useful for diverse applications. 相似文献
60.
Two new compounds based on mono copper(II)-substituted phosphomolybdate, [Cu4(tea)6(H4PMo11CuO39)(PMo12O40)]2·33H2O (1) and [Cu3(tea)6(H2O)2(H2PMo11CuO39)2]2·30H2O (2) (tea = 2- [1,2,4]triazol-4-yl-ethylamine), have been synthesized under hydrothermal conditions. Compound 1 owns tetra-nuclear clusters [Cu4(tea)6], linking a pair mono copper(II)-substituted and saturated Keggin anions to form a 2D structure. Compound 2 contains tri-nuclear clusters [Cu3(tea)6], fusing four mono copper(II)-substituted anions to construct a discrete four-membered cycle structure. 相似文献