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   275篇
  免费   18篇
电工技术   4篇
化学工业   71篇
金属工艺   7篇
机械仪表   15篇
建筑科学   5篇
矿业工程   1篇
能源动力   6篇
轻工业   42篇
石油天然气   1篇
无线电   29篇
一般工业技术   64篇
冶金工业   5篇
原子能技术   3篇
自动化技术   40篇
  2024年   3篇
  2023年   2篇
  2022年   5篇
  2021年   13篇
  2020年   8篇
  2019年   15篇
  2018年   18篇
  2017年   9篇
  2016年   16篇
  2015年   12篇
  2014年   17篇
  2013年   27篇
  2012年   14篇
  2011年   15篇
  2010年   10篇
  2009年   8篇
  2008年   11篇
  2007年   6篇
  2006年   7篇
  2005年   2篇
  2004年   8篇
  2003年   6篇
  2002年   6篇
  2001年   3篇
  2000年   3篇
  1999年   4篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1995年   3篇
  1994年   3篇
  1993年   4篇
  1991年   2篇
  1989年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1984年   2篇
  1983年   3篇
  1982年   2篇
  1981年   2篇
  1980年   1篇
  1977年   2篇
  1976年   3篇
  1974年   2篇
  1973年   1篇
  1971年   1篇
  1906年   5篇
  1905年   1篇
排序方式: 共有293条查询结果,搜索用时 15 毫秒
251.
The paper deals with symbolic approaches to bounded model checking (BMC) for the existential fragment of linear temporal logic extended with the epistemic component (ELTLK), interpreted over interleaved interpreted systems. Two translations of BMC for ELTLK to SAT and to operations on BDDs are presented. The translations have been implemented, tested, and compared with each other as well as with another tool on several benchmarks for MAS. Our experimental results reveal advantages and disadvantages of SAT- versus BDD-based BMC for ELTLK.  相似文献   
252.
We present herein a characterization of the microstructure and thermal properties of thermal barrier coatings (TBCs), which we obtained via plasma spraying of powder Gd2Zr2O7. By using X-ray diffraction (XRD) and electron backscatter diffraction (EBSD), we evaluated the phase composition of a ceramic layer and estimated the ceramic-layer stress state by the sin2ψ method. The tests revealed that the TBC layer consisted of a single-phase structure of Gd2Zr2O7, namely, an Fd3m lattice. The thermal diffusivity of the outer ceramic layer was determined based on a bilayer model and corrected with a factor to account for the presence of pores. The results reveal that the use of the standard parameters in a standard spraying process gives good-quality Gd2Zr2O7 TBCs with a thermal conductivity considerably lower than 8YSZ-type TBCs.  相似文献   
253.
ABSTRACT

Composition, structure and interfacial activity of alkanal oximes and kinetics of copper extraction from chloride solutions are discussed. Semiempirical self-consistent field calculations are used to study the structure of alkanal oximes and their mono- and dihydrates. These calculations are in a qualitative agreement with the ratio of alkanal (Z)-and (E)-isomers, interfacial activity and kinetics data.  相似文献   
254.
The effect of sterically hindered carbosilane moieties, situated as end groups in telechelic oligodimethylsiloxanes, was investigated with respect to the mobility of silicon atoms in the main chain. The relaxation phenomena in such crowded systems were studied by DSC and NMR methods. Spin–lattice relaxation times T 1 (29Si NMR) of silicon atoms in the oligomer chain were estimated and related to the distance between a given siloxane unit and the carbosilane moiety. It was found that the mobility of terminal siloxane units has been substantially affected. However, in the long range, the effect does not to seem to outweigh the intrinsic flexibility of the siloxane bonds.  相似文献   
255.
In this work, a study of the surface properties of treated indium tin oxide (ITO) substrates is reported. We used three different cleaning treatments among others: washing in an ultrasonic bath of acetone and ethyl alcohol or isopropyl alcohol in room temperature as well as dipping into solution (prepared from NH4OH (25 %), H2O2 (30 %) and distilled water) at 60 °C. The relation between ITO morphology and surface properties has been studied by contact angle, and surface energy measurements as well as the surface roughness of ITO samples evaluation by atomic force microscopy (AFM). Experimental results show that the ITO surface properties are closely related to the treatment methods. The ultrasonic degreasing in acetone and ethyl alcohol yields the highest surface energy (38.5 mJ/m2), brings about the maximum reduction in contact angles and causes the smallest increasing the surface roughness of ITO substrates.  相似文献   
256.
We have developed a simple process to form epitaxial CoSi2 for shallow junctions. Prior to metal deposition, the patterned wafers were treated with HF-vapor passivation. As observed by scanning tunneling microscopy (STM), this HF treatment drastically improves the native oxide-induced surface roughness. The epitaxial behavior was confirmed by cross-sectional transmission electron microscopy (TEM). Decreased sheet resistance and leakage current, and improved thermal stability are displayed by the HF treated samples, which is consistent with STM and TEM results  相似文献   
257.
258.
A group of cationic gemini surfactants (bisquaternary ammonium bromides) with different spacer chain lengths (8–6–8, 8–7–8, 8–8–8, 8–9–8) was investigated, paying special attention to antimicrobial and the cytotoxic properties as well as their antimicrobial activity during long‐term storage. It was shown that the compounds investigated exhibit excellent antimicrobial activity against Gram‐positive bacteria (Staphylococcus aureus) and Gram‐negative bacteria (Pseudomonas aeruginosa) as well as antifungal properties (Candida albicans). The gemini surfactants tested had the differential level of cytotoxicity against normal lymphocytes. It was shown that the spacer chain length plays an important role in antibacterial activity and influences the cytotoxicity. The gemini surfactants with shorter spacer chain length, that had higher critical micelle concentration, showed generally weaker antibacterial properties, but on the other hand, these exhibited lower level of cytotoxicity. Furthermore, the aqueous solution of gemini surfactants exhibited the same antimicrobial activity even after 3 months.  相似文献   
259.
The effect of copper oxides on the curing behaviors of the bismaleimide triazine (BT) prepreg is studied with infrared spectroscopy (IR), attenuated total reflection infrared spectroscopy (ATR), and X‐ray photoelectron spectroscopy (XPS). The result of IR analyses indicates that there is a concentration distribution present in the prepreg surface layer and the outer surface layer contains less cyanate, imide, and epoxide but more triazine groups than the inner layer. From ATR, it is concluded that the cuprous oxide attracts more cyanate ester resins but less bismaleimide resins from the prepreg to its surface than the cupric oxide. The copper surface affects the curing extent of the BT resin in contact and the cupric oxide has a more pronounced effect than the cuprous oxide, and this surface effect can extend to at least two microns deep into the BT prepreg from the contacted interface. The XPS results confirm that the BT/CuO interface contains more thermally stable and polar functional groups than the BT/Cu2O interface, and both two copper oxides attract only a small amount of brominated epoxy resin onto their surfaces. These results are attributed to the difference in preferential adsorptions and catalytic curing effects of two copper oxides on the BT prepreg in contact.

The intensity changes of IR bands obtained from BT prepreg during cure.  相似文献   

260.
Progress in microelectronic technology is extremely fast and it is outstripping the designers' abilities to make use of the created opportunities. Development and application of new more suitable design methods and tools is therefore very important for the modern system industry. This paper shows the importance of the AI search techniques for the circuits and systems design space exploration, explains what sorts of search techniques are useful for this aim, and discusses the place, role and way of use of these techniques in circuit and system design. In particular, the paper explains the importance and usage of the heuristic search techniques for the automatic construction and selection of the most promising solutions to the circuit synthesis problems. The discussion and conclusions of the paper are illustrated with examples of three effective and efficient search algorithms, and experimental results from their application to two important circuit synthesis problems. The knowledge presented in the paper combines numerous valuable concepts of modern system engineering and artificial intelligence, and forms a base for further research and application of the AI search techniques to design of complex circuits and systems.  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