全文获取类型
收费全文 | 73篇 |
免费 | 7篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 4篇 |
综合类 | 12篇 |
化学工业 | 2篇 |
金属工艺 | 6篇 |
机械仪表 | 21篇 |
建筑科学 | 1篇 |
矿业工程 | 1篇 |
轻工业 | 1篇 |
武器工业 | 6篇 |
无线电 | 3篇 |
一般工业技术 | 5篇 |
冶金工业 | 2篇 |
自动化技术 | 18篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 7篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 4篇 |
2012年 | 6篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 6篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
排序方式: 共有82条查询结果,搜索用时 15 毫秒
21.
22.
23.
H. C. Kuo J. M. Kuo Y. C. Wang C. H. Lin H. Chen G. E. Stillman 《Journal of Electronic Materials》1997,26(8):944-948
We report the determination of band offset ratios, using photoluminescence excitation measurements, for GaInP/GaAs and AlInP/GaAs
quantum wells grown by gas-source molecular beam epitaxy. To reduce the uncertainty related to the intermixing layer at heterointerfaces,
the residual group-V source evacuation time was optimized for abrupt GalnP/GaAs (AlInP/GaAs) interfaces. Based upon thickness
and composition values determined by double-crystal x-ray diffraction simulation and cross-sectional transmission electron
microscopy, the transition energies of GalnP/GaAs and AlInP/GaAs quantum wells were calculated using a three-band Kane model
with varying band-offset ratios. The best fit of measured data to calculated transition energies suggests that the valence-band
offset ratio (γ band discontinuity) was 0.63 ± 0.05 for GalnP/GaAs and 0.54 ± 0.05 for AlInP/GaAs heterostructures. This result
showed good agreement with photoluminescence data, indicating that the value is independent of temperature. 相似文献
24.
Suppose a user located at a certain vertex in a road network wants to plan a route using a wayfinding map. The user's exact destination may be irrelevant for planning most of the route, because many destinations will be equivalent in the sense that they allow the user to choose almost the same paths. We propose a method to find such groups of destinations automatically and to contract the resulting clusters in a detailed map to achieve a simplified visualization. We model the problem as a clustering problem in rooted, edge‐weighted trees. Two vertices are allowed to be in the same cluster if and only if they share at least a given fraction of their path to the root. We analyze some properties of these clusterings and give a linear‐time algorithm to compute the minimum‐cardinality clustering. This algorithm may have various other applications in network visualization and graph drawing, but in this paper we apply it specifically to focus‐and‐context map generalization. When contracting shortest‐path trees in a geographic network, the computed clustering additionally provides a constant‐factor bound on the detour that results from routing using the generalized network instead of the full network. This is a desirable property for wayfinding maps. 相似文献
25.
Procedural modeling allows for the generation of innumerable variations of models from a parameterized, conditional or stochastic rule set. Due to the abstractness, complexity and stochastic nature of rule sets, it is often very difficult to have an understanding of the diversity of models that a given rule set defines. We address this problem by presenting a novel system to automatically generate, cluster, rank, and select a series of representative thumbnail images out of a rule set. We introduce a set of ‘view attributes’ that can be used to measure the suitability of an image to represent a model, and allow for comparison of different models derived from the same rule set. To find the best thumbnails, we exploit these view attributes on images of models obtained by stochastically sampling the parameter space of the rule set. The resulting thumbnail gallery gives a representative visual impression of the procedural modeling potential of the rule set. Performance is discussed by means of a number of distinct examples and compared to state‐of‐the‐art approaches. 相似文献
26.
27.
考虑连杆弹性的曲柄滑块机构为受约束刚弹耦合机械系统,采用Kane方程,将连杆弹性变形用伽辽全法离散成空间函数和广义坐标的乘积,计及轴向缩短对连杆角速度的影响,推导出弹性连杆多自由度线性参激振动方程组。应用多尺度法并结合笛卡尔坐标变换,分析连杆第一阶弯曲模态的主参激共振,获得平凡响应稳定性临界曲线,并讨论阻尼比和惯性比等参数的影响。 相似文献
28.
介绍唐山中厚板材有限公司炼钢工作部的连铸机的火焰切割机与切割定尺,及采取的有效改造措施,以满足稳定生产的要求。 相似文献
29.
30.
安装在直升机桅杆顶部的雷达需要进行轻小型设计,同时又要适应严酷的力学环境,减重与提高系统的刚性通常是一对矛盾。为了在轻小型状态下提高系统抗力学环境的能力,需要对此类雷达进行动力学分析及主动振动抑制方法的研究。文中利用 Kane 方法推导了直升机载雷达的动力学理论模型,验证了模型的正确性,求解了直升机载雷达的振动变形情况,给出了主动抑振方法,求解了抑振效果,为直升机载雷达的主动振动抑制研究提供了理论基础。 相似文献