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   79篇
  免费   2篇
化学工业   14篇
金属工艺   5篇
能源动力   9篇
轻工业   2篇
石油天然气   1篇
无线电   23篇
一般工业技术   10篇
冶金工业   10篇
原子能技术   1篇
自动化技术   6篇
  2021年   2篇
  2020年   2篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2016年   3篇
  2015年   1篇
  2014年   3篇
  2013年   10篇
  2012年   3篇
  2011年   5篇
  2010年   2篇
  2009年   6篇
  2008年   2篇
  2007年   5篇
  2006年   2篇
  2004年   2篇
  2003年   1篇
  2002年   2篇
  2001年   3篇
  2000年   1篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1993年   1篇
  1992年   2篇
  1990年   3篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   4篇
  1979年   2篇
排序方式: 共有81条查询结果,搜索用时 15 毫秒
21.
The field of neural networks is being investigated by many researchers in order to provide solutions to difficult problems in the area of manufacturing systems. Computer simulation of neural networks is an important part of this investigation. This paper applies concepts from an important trend in software engineering research, namely object-oriented programming, to model neural networks.The design and implementation of a software object library is crucial to obtaining the full benefits of object-oriented programming. In this paper we discuss the design and implementation of a foundation library of software objects for the purpose of simulating and validating different network architectures and learning rules. The library contains objects that implement various types of nodes and learning rules. We discuss the results of our experiments to illustrate the benefits of using an object-oriented approach to modeling neural networks.  相似文献   
22.
The paper starts with experience curve analysis in order to find out the future prices of solar photovoltaic (PV) modules. Experience curves for 75-90% progress ratio are extrapolated with the help of estimated future growth rate for PV installation worldwide and current module price data until year 2060. A kWh PV electricity generation cost has been calculated for coming decades with the help of local market parameters and module prices data from extrapolated experience curve. Two different prices for grid electricity - wholesale electricity price and end user electricity price - are separately analyzed. Household electricity consumption profile and PV electricity generation profile for Cologne, Germany, have been analyzed to find out the possibility for PV electricity consumption at the time of its generation. This result is used to calculate the real grid parity year - which lies somewhere between grid parity years calculated for wholesale electricity price and end user electricity price.  相似文献   
23.
For uniform thermal conditions on 3-D irregular shaped design objects, this paper reports estimation of optimal power of the panel heaters placed along the walls of a 3-D radiant furnace. Hemispherical, cylindrical, conical, and a combination of cylindrical and conical, and finally a case study of a car body model are considered as the design objects (DOs). The entire surface areas of the furnace walls and that of the DO are divided into surface elements. The surface elements of the furnace walls are made of the panel heaters. In this boundary design problem, the objective function is developed as an error function of estimated and the desired heat fluxes on the surfaces of DO. The radiative exchange among the surface elements is computed using the radiation element method by ray emission model (REM2), and the objective function is minimized using the micro-genetic algorithm (MGA). Power of the panel heaters are estimated for different sizes of the DOs. Although the panel heaters have been placed along the furnace walls, for uniform thermal conditions, for a given DO, not all are required. Having known that not all are required, to ease the control, estimations have also been shown by grouping the heaters along the furnace walls. This study provides a guideline for a priori knowing the heater setting and their corresponding power requirement in heating of 3-D irregular shaped objects.  相似文献   
24.
Pattern Analysis and Applications - This paper proposes a novel behavior-inspired recommendation algorithm named TimeFly algorithm, which works on the idea of altering behavior of the user with...  相似文献   
25.
Problems in preparation of FeZSM-5 catalysts   总被引:1,自引:0,他引:1  
FeZSM-5 catalysts for SCR of NO to N2 can be made in a highly durable form that may be useful for automotive exhaust cleanup, but not presently reproducible. Herein we outline the properties and characteristics of good versus poor catalysts and provide results of experiments that effect the properties of the final preparation. It is shown how Mössbauer characterization will be useful in understanding the changes that occur as the catalysts age. The problem has not yet been resolved. This letter is meant to challenge research by others.  相似文献   
26.
Experimental results on sediment removal efficiency of vortex chamber type sediment extractors are reported. A geometric configuration of the extractor is identified that is able to remove even the fine sediment (0.055 ? d ? 0.22?mm) from flow with high efficiency. For the purpose of analysis, the experimental data of present study are compiled with the data from other laboratories and the field that were collected previously by other investigators. Since the existing relations are not found to produce satisfactory results, a new relationship is developed for determination of the sediment removal efficiency of the vortex chamber type sediment extractors.  相似文献   
27.
Titanium aluminide thin films are being considered as coating materials for high temperature applications due to their high melting points and high oxidation resistance. In this study, Ti37Al63 and Ti53Al47 thin films are deposited onto SiO2 substrates by RF magnetron sputtering using compound targets and then annealed in vacuum to investigate the properties of the films. Rutherford backscattering spectrometry, X-ray diffractometry, transmission electron microscopy, and four-point probe measurements are used to analyze the characteristics of Ti37Al63 and Ti53Al47 thin films for high temperature electronics applications. The films show good thermal stability up to 700 °C for 1 h in vacuum. Reasonable resistivity is obtained when appropriate compositions and anneal conditions are used.  相似文献   
28.
The renin–angiotensin–aldosterone system (RAAS) impacts cardiovascular homeostasis via direct actions on peripheral blood vessels and via modulation of the autonomic nervous system. To date, research has primarily focused on the actions of the RAAS on the sympathetic nervous system. Here, we review the critical role of the RAAS on parasympathetic nerve function during normal physiology and its role in cardiovascular disease, focusing on hypertension. Angiotensin (Ang) II receptors are present throughout the parasympathetic nerves and can modulate vagal activity via actions at the level of the nerve endings as well as via the circumventricular organs and as a neuromodulator acting within brain regions. There is tonic inhibition of cardiac vagal tone by endogenous Ang II. We review the actions of Ang II via peripheral nerve endings as well as via central actions on brain regions. We review the evidence that Ang II modulates arterial baroreflex function and examine the pathways via which Ang II can modulate baroreflex control of cardiac vagal drive. Although there is evidence that Ang II can modulate parasympathetic activity and has the potential to contribute to impaired baseline levels and impaired baroreflex control during hypertension, the exact central regions where Ang II acts need further investigation. The beneficial actions of angiotensin receptor blockers in hypertension may be mediated in part via actions on the parasympathetic nervous system. We highlight important unknown questions about the interaction between the RAAS and the parasympathetic nervous system and conclude that this remains an important area where future research is needed.  相似文献   
29.
Germanium (Ge) possesses a great potential as a high‐capacity anode material for lithium ion batteries but suffers from its poor capacity retention and rate capability due to significant volume expansion by lithiation. Here, a facile synthetic route is introduced for producing nanometer‐sized Ge crystallites interconnected by carbon (GEC) via thermal decomposition of a Ge‐citrate complex followed by a calcination process in an inert atmosphere. The GEC electrode shows outstanding electrochemical performance, i.e., an almost 98.8% capacity retention of 1232 mAh g?1, even after 1000 cycles at the rate of C/2. Importantly, a high discharge capacity of 880 mAh g?1 is maintained at the very high rate of 10 C. The excellent anode performance of GEC stems from both effective buffering of carbon anchored to the Ge nanocrystals and the high open porosity of the GEC aggregated powder with an average pore diameter of 32 nm. Furthermore, the interfacial layer formed between Ge and carbon plays an essential role in prolonging the cycle life. The GEC electrode can be successfully employed as an anode for next generation lithium ion batteries.  相似文献   
30.
Using the catalytic chemical vapor deposition (Cat-CVD) method, polytetrafluoroethylene (PTFE) thin films were fabricated on Si(100) substrates at various catalyzer temperatures, using a tungsten catalyzer, and Fourier transform infrared (FTIR) spectroscopy and X-ray photoemission spectroscopy (XPS) were used to confirm the fabrication of the films. An atomic-force microscope (AFM) and a scanning electron microscope (SEM) were employed to study the correlation between the wettability and surface morphology of the samples. It was found that the wettability of the PTFE thin films fabricated via Cat-CVD is strongly correlated with the sizes of the film surfaces' nanoprotrusions, and that superhydrophobic PTFE thin-film surfaces can be easily achieved by controlling the sizes of the nanoprotrusions through the catalyzer temperature. The comparison of the wettability values and surface morphologies of the films confirmed that nanoscale surface roughness enhances the hydrophobic properties of PTFE thin films. Further, the detailed analysis of the films' surface morphologies from their AFM images with the use of the Wenzel and Cassie models confirmed that the nanoscale surface roughness enhanced the hydrophobic property of the PTFE films. Further, the variations of the wettability of the PTFE thin films prepared via Cat-CVD are well explained by the Cassie model. It seems that the increase in the trapping air and the reduction of the liquid-solid contact area are responsible for the superhydrophobicity of the PTFE thin films prepared via Cat-CVD.  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