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411.
Presented herein is an experimental study on the combustion of B4C/KNO3 binary pyrotechnic system.Combustion products were tested using X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive spectrometer(EDS).According to the results of tests and CEA calculation,the combustion reaction equation was established.The flames and burning rates were recorded by a high speed camera and a spectrophotometer.The effect of B4C particle size on the thermal sensitivity of B4C/KNO3 was investigated by differential scanning calorimetry(DSC)techniques.In addition,a reliable method for calculating the flame temperature was proposed.Based on the results of experiments,the combustion reaction mechanism was briefly analyzed.The burning rate,flame temperature and thermal sensitivity of B4C/KNC3 increase with the decrease of B4C particle size.The mass ratio of B4C/KNO3 has a great effect on combustion properties.Oxidizer-rich compositions have low flame temperatures,low burning rates,and provide green light emission.The combustion reactions of fuel-rich compositions are vigorous,and the B4C/KNO3 with mass ratio of 25:75 has the highest burning rate and the highest flame temperature. 相似文献
412.
A quick and accurate extraction of dominant colors of background images is the basis of adaptive camouflage design. This paper proposes a Color Image Quick Fuzzy C-Means (CIQFCM) clustering algorithm based on clustering spatial mapping. First, the clustering sample space was mapped from the image pixels to the quantized color space, and several methods were adopted to compress the amount of clustering samples. Then, an improved pedigree clustering algorithm was applied to obtain the initial class centers. Finally, CIQFCM clustering algorithm was used for quick extraction of dominant colors of background image. After theoretical analysis of the effect and efficiency of the CIQFCM algorithm, several experiments were carried out to discuss the selection of proper quantization intervals and to verify the effect and efficiency of the CIQFCM algorithm. The results indicated that the value of quantization intervals should be set to 4, and the proposed algorithm could improve the clustering efficiency while maintaining the clustering effect. In addition, as the image size increased from 128 × 128 to 1024 × 1024, the efficiency improvement of CIQFCM algorithm was increased from 6.44 times to 36.42 times, which demonstrated the significant advantage of CIQFCM algorithm in dominant colors extraction of large-size images. 相似文献
413.
Yue-ting Wang Xiao-ting Zhang Jian-bing Xu Yun Shen Cheng-ai Wang Fu-wei Li Ze-hua Zhang Jian Chen Ying-hua Ye Rui-qi Shen 《防务技术》2021,17(4):1307-1312
In this study, Al-CuO nanocomposites were fabricated by sol-gel method. As a contrast, the thermite was prepared by physical mixing at the equivalence ratio of 0.5, 1, 2, respectively. The intermediates and samples as prepared were characterized by SEM and XRD. The exothermic properties of the two samples prepared at different equivalence ratios were tested and the reaction products were characterized by XRD. The SEM results show that the sample prepared by the sol-gel method demonstrates a micron-sized agglomerated sphere formed by a mutual wrapping of Al NPs and CuO NPs, and the particles are evenly distributed in the agglomerate. In addition, when the content of Al powder is seriously insufficient, the heat release of the sample prepared by physical mixing is 1.6 times that of by sol-gel method. With the increase of Al powder content, the exothermic properties of Al/CuO NPs prepared by sol-gel method began to increase significantly compared with physical mixing and the difference is 1.5 times when the equivalence ratio increases to 2. It can be concluded that the reason for this result may be attributed to the different mass transfer modes of components due to the different morphologies of samples. 相似文献
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416.
运用数据挖掘的方式分析运动轨迹数据在目前可以说是一种尝试。基于传统数据挖掘方法Apriori的思想,提出了一种监控视频运动目标的频繁轨迹模式挖掘算法。首先以特征点表示连续的运动目标轨迹,然后设计了一种轨迹相似度测量机制,最后基于相似度测量获得的轨迹段频率,将Apriori挖掘算法应用到2D运动轨迹数据,从中发现频繁轨迹隐含的一些感兴趣模式。实际的和人工生成的轨迹数据实验表明了算法的正确有效性。 相似文献
417.
3mm波段混凝土屏蔽材料的研究 总被引:2,自引:0,他引:2
在混凝土中添加标准砂,钢纤维,铁晶矿砂,炭纤维毡,氧化锌晶须,铁氧体,乙炔碳黑,羰基铁粉等材料,制成了具有微波吸收性能的混凝土屏蔽材料,以期能探索一条大型建筑及军事掩体的电磁防护的新途径。在3mm波段范围内对混凝土屏蔽材料进行了初步的实验研究,研究了不同材料、不同掺量下电磁波的吸收衰减特性,并分析了它们之间的关系,为进一步的研究指明了方向。 相似文献
418.
讨论了某型惯导 ( INS)设备的结构、工作流程和故障特点 ,分析了基于知识的专家系统 ( ES)常用的诊断模型和推理方法 ,在此基础上 ,设计了具体的基于对象的惯导综合层次模型及其推理机 .该模型和推理机已实际应用于该型 INS的故障诊断专家系统的设计 相似文献
419.
指出了高等军事院校非计算机专业人才加强计算机基础教育的重要意义,结合我院的现状,提出了加强计算机基础教育的措施和模式. 相似文献
420.
Inventory transshipment is generally shown to be beneficial to retailers by matching their excess demand with surplus inventory. We investigate an inventory transshipment game with two newsvendor-type retailers under limited total supply and check whether the retailers are better off than the case without transshipment. We derive the ordering strategies for the retailers and show that unlike the unlimited supply case, a pure Nash equilibrium only exists under certain conditions. Furthermore, contrary to the conventional wisdom, we show that inventory transshipment may not always benefit both retailers. Although one of the retailers is guaranteed to be better off, the other could be worse off. The decision criteria are then provided for the retailers to determine if they will benefit from the exercise of inventory transshipment. Numerical study indicates that the carefully chosen transshipment prices play an important role in keeping inventory transshipment beneficial to both retailers. Subsequently, a coordinating mechanism is designed for the retailers to negotiate transshipment prices that maximize the total profit of the two retailers while keeping each of them in a beneficial position. 相似文献