首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   55篇
  免费   2篇
电工技术   4篇
化学工业   6篇
金属工艺   2篇
机械仪表   4篇
建筑科学   5篇
轻工业   3篇
水利工程   2篇
石油天然气   1篇
无线电   8篇
一般工业技术   8篇
自动化技术   14篇
  2022年   1篇
  2021年   2篇
  2020年   1篇
  2019年   1篇
  2017年   3篇
  2016年   2篇
  2015年   1篇
  2014年   2篇
  2013年   9篇
  2012年   4篇
  2011年   4篇
  2010年   3篇
  2009年   2篇
  2007年   4篇
  2005年   2篇
  2001年   3篇
  2000年   2篇
  1999年   2篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   3篇
  1993年   2篇
  1992年   1篇
排序方式: 共有57条查询结果,搜索用时 656 毫秒
1.
胡传志  程显毅  曹小峰 《计算机科学》2015,42(1):272-275,307
敏感信息过滤是既重要又复杂的任务.针对当前一些敏感信息过滤模型所存在的时间滞后、准确性低、自适应性差等问题,提出了一个敏感信息自适应多重过滤模型.该模型以互联网中文文本媒体为研究对象,采用意见挖据、机器学习、高性能计算和自然语言处理等技术,从整体和语义角度自适应识别敏感信息.对敏感信息自适应多重过滤模型的研究将为舆情监控、商业智能、辅助决策等应用系统开发提供技术支持.  相似文献   
2.
提出了中厚板轧机轧制力计算模型,并在此基础上,对数学模型进行在线自适应,使计算得到的轧制力更接近于实测值。  相似文献   
3.
周丽华  邓慧敏 《广东化工》2010,37(8):261-262,243
采用3-氨基喹啉(3-AQ)、二元基体3-AQ/2,5-二羟基苯甲酸(DHB)及常用于糖类物质测定的DHB和二元基体DHB/1-羟基异喹啉(1-HIQ)对一天然提取植物糖样进行了基体辅助激光解吸/电离飞行时间质谱(MALDI-TOF MS)分析。实验结果表明:此植物糖样由线形和环形聚己糖组成,其最大分子量至少达3000 Da;3-AQ与常用基体DHB及DHB/HIQ相比较,能提供更准确、更全面的样品组成及分子结构信息,且具有优越于常用基体解吸电离环状糖分子的能力。  相似文献   
4.
对移动终端桌面增值业务进行了研究,简要介绍移动终端桌面业务概念,重点叙述移动终端桌面系统构成以及组成部分的功能,并给出业务的运行环境和一些流程示例,最后对业务实施提出几点建议。  相似文献   
5.
文章首先提出了一种新的均衡技术,即DFE插入MLSE的DFE/MLSE自适应均衡器结构,接着提出了如何用FPGA实现该均衡器。  相似文献   
6.
The method of testing the uniform single-layer corrosion resisting coating, produced by electroslag strip cladding on 10GN2MFA steel, on the resistance to low-cycle fatigue strength using special specimens is described. Tests were carried out at a temperature of 20 °C with the symmetric axial tension–compression loading cycle (Re = –1) with the given amplitude of the parent and cladding metal. The tests were carried out in the strain amplitude range εa = 0.28–0.8%, the number of cycles to the initiation of a crack was Ni = 340–16,000 cycles, loading frequency f = (0.25–2.0). The area of formation of the cracks was recorded in the experiments. In most cases, the cracks formed in the heat-affected zone in the vicinity of the fusion line and propagated in both the parent and deposited metal. The results show that in the range of low-cycle fatigue for the investigated 10GN2MFA steel with a deposited layer, the calculation coefficient of the decrease of the cyclic strength of the metal with a deposited layer in relation to the fatigue curve for the carbon and alloyed steel with 0.8 ≤ σ0.2/σB ≤ 0.9, the value φS = 0.68 should be used in the calculations.  相似文献   
7.
This study provides insight into consumers’ perception of regionality when purchasing regional wine in terms of regional specialisation for style, volume of production of the wine style, quality of the wine, heritage of the wine region and the distinctiveness of the wine styles produced in the wine regions of Australia. Data were collected from 203 Australian wine consumers through an online survey. The study compares the results of this study with Easingwood et al. [2011. The drivers of wine regionality. Journal of Wine Research, 22(1), 19–33.] study on experts’ opinion of regionality drivers. This paper will expand knowledge on how consumer involvement levels impact decisions relating to purchasing regional wine. This study is of value to academics and wine practitioners alike. It contributes to the wine literature by providing a new perspective on consumers’ perception and draws attention to the risk of drawing conclusions about wine consumption based on experts’ opinions as being reflective of the average consumers’ purchase decision-making.  相似文献   
8.
Abstract

Thermal barrier coatings (TBCs) of yttria partially stabilized zirconia were deposited on gamma TiAl samples using electron-beam physical vapour deposition. The specimens were coated with intermetallic Ti –Al – Cr layers and CrAlYN/CrN nanoscale multilayer coatings. The lifetime of the TBC systems was determined performing cyclic oxidation tests in air at temperatures between 850 and 950–C. The TBC systems with Ti –Al – Cr and CrAlYN/CrN layers did not fail at 850 and 900–C during the maximum exposure time period of 1000 cycles of 1 h dwell time at high temperature. No spallation of the thermal barrier coatings was observed. As revealed by post-oxidation microstructural analysis, the protective coatings were severely degraded when exposed at 900–C, resulting in growth of mixed oxides on the substrate. Underneath the thermal barrier coating an outer oxide scale with a columnar structure was observed, consisting of rutile and α-Al2O3. Energy-dispersive X-ray spectroscopy analysis revealed zirconia and chromia being dissolved in the outer oxide scale. The columnar structure and the presence of zirconia indicated an effect of the TBC on the morphology of the outer oxide scale. The zirconia top coat exhibited an excellent adherence to this oxide scale formed on the protective layers when degraded, and at defects like cracks. When thermally cycled at 950–C, the TBC system on specimens coated with Ti –Al – Cr failed by spallation of the thermally grown mixed oxides, whereas the thermal barrier coating was well adherent to the outer oxide scale at this temperature, too.  相似文献   
9.
Abstract

The synthesis, crystal structure and electrical conductivity properties of Cu-doped ZnO powders (in the range of 0.25 – 15 mole %) is reported. I-phase samples, which were indexed as single phase with a hexagonal (wurtzite) structure in the Cu-doped ZnO binary system, were determined by X-ray diffraction. The limit solubility of Cu in the ZnO lattice at this temperature is 5 mole % at 1000°C. The impurity phase was determined as CuO when compared with standard XRD data using the PDF program. We focused on single I-phase ZnO samples which synthesised at 1000°C because the limit solubility range is widest at this temperature. It was observed that the lattice parameters a increased and c decreased with Cu doping concentration. The morphology of the I-phase samples was analysed with a scanning electron microscope. The electrical conductivity of the pure ZnO and single I-phase samples were studied using the four-probe dc method at temperatures between 100 and 950°C in an air atmosphere. The electrical conductivity values of pure ZnO and 5 mole % Cu-doped ZnO samples at 100°C were 2 × 10?6 and 1.4 × 10?4 ohm?1 cm?1, and at 950°C they were 1.8 and 3.4 ohm?1 cm?1, respectively. In other words, the electrical conductivity slightly increased with Cu doping concentration. Also, it was observed that the activation energy of the I-phase samples was decreased with Cu doping concentration.  相似文献   
10.
Abstract

Composite portraiture has a long history which is not, of course, confined to this country, but it flourished here to a significant and, perhaps, astonishing degree during the 19th century. The purpose of the composites was usually commercial. Members of a congress might be so portrayed in collective fashion, or else a professional portrait photographer might take advantage of his accumulated files and issue a composite as his firm's advertisement. In this fashion the Burton Brothers of New Zealand made a fascinating composition between 1867 and 1877, which has already been published in another context1 , but is here reproduced for easy reference (Figure 1). The firm's shop-front is shown in the centre with the two photographers on either side. Above the shop-front are portraits of Captain Cook, Captain Cargill (the leader of the Otago settlement), Queen Victoria (the royal patron of the firm), and julius Vogel (the Premier of New Zealand in 1873), together with local administrators and other dignitaries. In the top corners are the bishops of the Anglican and Roman Catholic churches; below are the wives of the photographers. There are some 785 portraits in all. There is also, woven into the composite, the wording ‘hotography Burton Bros Dunedi’ which has been cut out and superimposed on the pasted-up portraits. Closer inspection reveals much humour. Under the words ‘Burton Bros’ are two photographs of seances or ghost pictures. In the ‘U’ of the word ‘unedi’ Alfred Burton himself appears, dressed up as Uncle Sam. A man who is thought to be Walter Burton appears in a nightshirt between the ‘I’ and ‘N’, and he is certainly the figure making strange gestures in two shots beyond the ‘N’. Between the ‘N’ and ‘E’ Alfred again appears, dignified in Masonic dress, while an adoring female worships him from the proximity of the adjacent ‘N’. A dog even turns up between the ‘H’ and ‘Y’ of the word ‘hotograph’. An interesting feature is the photographic caricature of a man with a large head on a small body, reminiscent of an 1876 example shown by Gaston Tissandier, who also gave some rather obvious instructions to enterprising montage artists: To represent a large head on a small body a picture of the head alone is first taken and then a picture of the entire body on a much smaller scale. Proofs are taken on paper from the two negatives, and then the large head is cut out and pasted on to the shoulders of the figure on the smaller scale. If the large head does not fit very well on to the small body the neck is touched up with a brush. A photograph is then taken of the picture thus obtained, and the negative produced will furnish any number of caricature proofs2. For sheer photographic fun, the Burton work is an outstanding example of its kind.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号