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101.
采用透射电镜研究了以膨胀石墨为主体材料合成的CuCl2-EGICs微观结构,包括垂直和平行石墨碳原子层的层间结构,层面结构,根据X射线衍射参数计算获得2、3、4阶CuCl2-EGICs的层间距Ic值,与理论计算值近拟。 相似文献
102.
Heat-induced Egg White Gels as Affected by pH 总被引:3,自引:0,他引:3
AKIHIRO HANDA KEIKO TAKAHASHI NAMIO KURODA GLENN W. FRONING 《Journal of food science》1998,63(3):403-407
The functional properties of heat-induced egg white gels were investigated at five pH values. Textural characteristics were determined using the Instron Universal Machine. Hardness, elasticity, cohesiveness, chewiness, and fracturability were maximum at pH 11. Hunter L values were maximum at pH 5 and 7. Microstructure studied with electron microscopy was distinctly different at the five pH values. Alkaline gels showed a fine ordered network that might have contributed to excellent textural characteristics. Water-holding capacity (WHC) was high at alkaline pH, but decreased with addition of 2-mercaptoethanol, suggesting that disulfide bonds were important in egg white gels. Sodium dodecyl sulfate (SDS) improved WHC at pH 7 and 9. No significant correlation was observed between textural profiles and WHC. 相似文献
103.
采用高分辨透射电镜(HRTEM)对安装了金属型汽油机颗粒捕集器(GPF)的汽油缸内直喷(GDI)发动机颗粒物进行观察,研究了转速为1500 r/min,负荷分别为25%、50%、75%和100%工况下的GPF前、后端颗粒物微观形貌及微观结构参数变化.结果表明:组成颗粒物的基本粒子均呈近似球形,堆积形成链状、枝状和环状等不规则几何形状,负荷和GPF对颗粒物微观形貌无明显影响;GPF前、后端收集的颗粒物基本粒子绝大多数为“外壳-内核”结构;GPF前、后端颗粒物的微晶尺寸、层间距和曲率均呈单峰分布,其中,GPF前、后端平均微晶尺寸随负荷的增加而增大,而平均层间距、平均曲率的变化规律则相反,说明颗粒物石墨化程度随负荷的增加而增大.负荷和GPF仅对颗粒物微观结构参数的大小有影响,对其分布规律没有影响. 相似文献
104.
This article presents the influence of cell size and cell wall volume fraction on the failure parameters of potato tuber and carrot tissue. Confocal scanning laser microscope was used for obtaining images of the cell structure of the tissues. The mean cell face area and the cell wall volume fraction obtained from the images was compared with work to failure, failure stress, failure strain and secant modulus obtained in a compression test of potato and carrot tissue at two strain rates. Bigger cells and less amount of cell wall material weakened the tissue, which was visible as a linear decrease in the parameters: work to failure, failure stress and failure strain. There were differences between potato and carrot in the secant modulus. For carrot, the secant modulus changed with microstructural parameters, whereas for potato, the secant modulus did not depend on these values. The strain rate decreases all the failure properties for potato. For carrot, only the work to failure was affected by the strain rate. 相似文献
105.
采用飞秒激光切割和微细电阻滑焊组合的方法制备了高深宽比的三维微结构。为了提高每层二维微结构的叠加精度和连接强度,用逐层微细电阻滑焊对每层二维微结构进行滑焊以获得较好的工艺参数。对上述工艺参数所制备的微结构进行了抗剪切能力测试,测试结果显示:随着滑焊放电次数的增加,微结构的极限剪切力由8.04N逐渐增加至65.97N。而后,通过能量分散光谱仪(EDS)对电极的沉积效应进行了研究。最后,在120mW的飞秒激光,50μm/s的切割速度,0.21V的焊接电压,0.2MPa的焊接压强,100ms的预压时间,10ms的焊接时间以及160次的滑焊放电次数等工艺参数下制备了基本尺寸为50μm×50μm的微方孔阵列以及微齿轮结构。实验结果表明:通过逐层微细电阻滑焊制备的微结构表面质量良好,各层微结构之间叠加较好,显示逐层微细电阻滑焊可以较好地保证三维微结构中各层二维微结构的连接强度和叠层精度。 相似文献
106.
The investigations results of the different types of high-voltage nanosecond atmospheric discharges(diffusive in the gaps "wire(cathode)-plane", "rod(cathode)-plane", spark "point-plane" and in homogeneous gaps "plane-plane", as well as streamerless discharges in homogeneous gaps "plane-plane") are present. It was found out that the current channels prints, left on the electrodes surface, has the microstructure. The microstructure is a cluster(up to 1 000) of the microchannels of 1~30 μm diameters almost evenly distributed on the channels section. It was found out that in some cases the discharges develop in the regime of microstructuring of the current channels, are accompanied by generation of high-energy electrons and x-ray radiation. In this case the generation of high-energy component is stipulated by the electrons runaway in the microchannels. The calculation results of the electric field in clusters of parallel microchannels in the frameworks of the model of a bundle of parallel long cylindrical conductors are present. It is shown that in the clusters with many microchannels in the result of mutual attenuation of their fields maximum strength of the radial field could be lower than the critical one, which is necessary for ionization multiplication and expansion. This provides long existence of microchannels groups of microns radii in the high-voltage nanosecond discharges. A physical model of the streamerless discharge microstructure formation at the result of instability development of the ionization process in the avalanche stage is developed. It was established that the instability has long wave character and leads to formation of self-similar spatial structure. It is shown that the microstructure of the streamer discharges could be explained in the frameworks of this model. Three-dimensional numerical simulation of dynamics of microchannels system of high-voltage nanosecond discharges in the air of atmospheric pressure is performed in hydrodynamic approximation. It is established that fast(≈10 ns) expansion and significant decreasing of the gas concentration in the microchannels takes place at the expense of ohmic heating of the microchannels. It is shown that the microchannels expansion provides increase of electric field and gas concentration ratio up to the values that are sufficient for high-energy electrons beams and bremsstrahlung generation in them. 相似文献
107.
108.
高压成型铝硅系列合金晶粒组织控制及其强化技术的研究进展 总被引:1,自引:0,他引:1
综述了高压条件下的铝硅系列合金的晶粒组织控制及其强化技术,介绍了我国高压成型的产业化情况.高压条件下结晶的零件性能高低主要取决于结晶前的液态金属结构和成型过程中的结晶条件,零件强化的主要工艺措施有热速处理、细化处理以及压力下结晶.开展铝硅合金结晶的晶粒组织控制模拟仿真技术研究的理论主要是基于第一性原理和物理统计学理论,根据Monte-carlo模型和CA模型进行.结合高压成型实际生产工艺,说明了高压成型的晶粒组织控制的可行性. 相似文献
109.
110.