首页 | 官方网站   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   179篇
  免费   2篇
工业技术   181篇
  2020年   5篇
  2018年   3篇
  2017年   2篇
  2016年   2篇
  2015年   2篇
  2014年   4篇
  2013年   6篇
  2012年   7篇
  2011年   6篇
  2010年   8篇
  2009年   7篇
  2008年   8篇
  2007年   13篇
  2006年   13篇
  2005年   14篇
  2004年   9篇
  2003年   10篇
  2002年   5篇
  2001年   4篇
  2000年   3篇
  1999年   4篇
  1998年   7篇
  1997年   6篇
  1996年   6篇
  1995年   5篇
  1992年   1篇
  1991年   2篇
  1989年   1篇
  1986年   1篇
  1982年   1篇
  1976年   6篇
  1975年   1篇
  1969年   2篇
  1968年   1篇
  1967年   1篇
  1966年   3篇
  1965年   1篇
  1963年   1篇
排序方式: 共有181条查询结果,搜索用时 15 毫秒
31.
Abstract— Low‐temperature polysilicon (LTPS) technology has a tendency towards integrating all circuits on glass substrate. However, the poly‐Si TFTs suffered poor uniformity with large variations in the device characteristics due to a narrow laser process window for producing large‐grained poly‐Si TFTs. The device variation is a serious problem for circuit realization on the LCD panel, so how to design reliable on‐panel circuits is a challenge for system‐on‐panel (SOP) applications. In this work, a 6‐bit R‐string digital‐to‐analog converter (DAC) with gamma correction on glass substrate for TFT‐panel applications is proposed. The proposed circuit, which is composed of a folded R‐string circuit, a segmented digital decoder, and reordering of the decoding circuit, has been designed and fabricated in a 3‐μm LTPS technology. The area of the new proposed DAC circuit is effectively reduced to about one‐sixth compared to that of the conventional circuit for the same LTPS process.  相似文献   
32.
A new ball and beam system is constructed using a pair of magnetic suspension actuators in this paper. The proposed system can be used not only as a control theory verification and practice platform, but also as an educational demonstration and training tool for system integration of electrics, mechanics and cybernetics. The proposed control system activates two magnetic suspension actuators on either side of the beam. The magnetic force, as a function of position and coil current, was measured and modelled by a quadratic function. The system mathematical model is derived by the Lagrangian function. For control performance, a single chip microprocessor as control kernel with basic electronic components is designed and implemented. The ball and beam system hardware as well as microprocessor-based control circuit is implemented and tested. The static and dynamic performance of the ball and beam system is tested with several different scenarios. The system operation on oscillatory stabilization and sinusoidal tracking is verified with excellent operational characteristics.  相似文献   
33.
Abstract— A digital time‐modulation pixel memory circuit on glass substrate has been designed and verified for a 3‐μm low‐temperature polysilicon (LTPS) technology. From the experimental results, the proposed circuit can generate 4‐bit digital codes and the corresponding inversion data with a time‐modulation technique. While the liquid‐crystal‐display (LCD) panel operates in the still mode, which means the same image is displayed on the panel, a data driver for an LCD panel is not required to provide the image data of the frame by the proposed pixel memory circuit. This pixel memory circuit can store the frame data and generate its corresponding inversion data to refresh a static image without activating the data driver circuit. Therefore, the power consumption of a data driver can be reduced in the LCD panel.  相似文献   
34.
This article offers a fresh reading of the Water Framework Directive (WFD) and of the Common Implementation Strategy guidance document number 8 on public participation (PP) aimed at identifying the conditions required for successful implementation. We propose that a central barrier to implementing Article 14 is that Integrated Water Resources Management (IWRM) problems are complex in character and that participation is a wicked process in practice. This article highlights some ambiguous interpretations of the WFD comparing and contrasting the ‘letter of the law’ and its ‘spirit’, based on a critical review of the nature of PP, who it concerns and when it takes place. First we articulate a complex system interpretation of IWRM in the context of the WFD. Second, we explain the difficulty to define blueprint for PP in IWRM. Finally, we present five interpretative challenging readings in order to highlight tensions between the ‘spirit’ and the ‘letter’ of the WFD.  相似文献   
35.
The EUBIONET III project has boosted (i) sustainable, transparent international biomass fuel trade, (ii) investments in best practice technologies and (iii) new services on biomass heat sector. Furthermore, it identified cost-efficient and value-adding use of biomass for energy and industry. The aims of this article are to provide a synthesis of the key results of this project. Estimated annual solid biomass potential in the EU-27 is almost 6600 PJ (157 Mtoe), of which 48% is currently utilised. The greatest potential for increased use lies in forest residues and herbaceous biomass. Trade barriers have been evaluated and some solutions suggested such as CN codes for wood pellets and price indexes for industrial wood pellets and wood chips. The analysis of wood pellet and wood chip prices revealed large difference amongst EU countries, but also that on the short term prices of woody and fossil fuels are barely correlated. Sustainable production and use of solid biomass are also deemed important by most European stakeholders, and many support the introduction of harmonised sustainability criteria, albeit under a number of preconditions. The study identified also that a number of woody and agro-industrial residue streams remain un- or underutilised. The estimated European total potential of agro-industrial sources is more than 250 PJ (7.2 Mtoe), the amount of unutilised woody biomass (the annual increment of growing stock) even amounts to 3150 PJ (75 Mtoe). Finally 35 case studies of biomass heating substituting fossil fuels were carried out, showing that the potential to reduce GHG emissions ranges between 90 and 98%, while costs are very similar to fossil fuel heating systems. Overall, we conclude that solid biomass is growing strongly, and is likely to heavily contribute to the EU renewable energy targets in the coming decade.  相似文献   
36.
37.
Abstract

The asymptotic stability problem for a class of neutral systems with time‐varying delays and nonlinear uncertainties is investigated in this paper. LMI‐based delay‐dependent criteria are proposed to guarantee the asymptotic stability of the considered systems. New Lyapunov‐Krasovskii functional and Leibniz‐Newton formulae are used to find the delay‐dependent stability results. Finally, some numerical examples are illustrated to show the improved results from using this method.  相似文献   
38.
We are presenting a new approach of identifying sources of variability within a manufacturing process by NIR measurements of samples of intermediate material after each consecutive unit operation (interprocess NIR sampling technique). In addition, we summarize the development of a multivariate statistical process control (MSPC) model for the production of enteric-coated pellet product of the proton-pump inhibitor class. By developing provisional NIR calibration models, the identification of critical process points yields comparable results to the established MSPC modeling procedure. Both approaches are shown to lead to the same conclusion, identifying parameters of extrusion/spheronization and characteristics of lactose that have the greatest influence on the end-product’s enteric coating performance. The proposed approach enables quicker and easier identification of variability sources during manufacturing process, especially in cases when historical process data is not straightforwardly available. In the presented case the changes of lactose characteristics are influencing the performance of the extrusion/spheronization process step. The pellet cores produced by using one (considered as less suitable) lactose source were on average larger and more fragile, leading to consequent breakage of the cores during subsequent fluid bed operations. These results were confirmed by additional experimental analyses illuminating the underlying mechanism of fracture of oblong pellets during the pellet coating process leading to compromised film coating.  相似文献   
39.
In this study, the possibility of preparation and application of highly porous silica aerogel-based bioactive materials are presented. The aerogel was combined with hydroxyapatite and p.tricalcium phosphate as bioactive and osteoinductive agents. The porosity of aerogels was in themesoporous region with a maximum pore diameter of 7,4 and 12.7 nm for the composite materials. The newly developed bioactive materials were characterized by scant electron microscopy. The in vitro biological effect of these modified surfaces was also tested on SAOS-2 osteogenic sarcoma cells by confocal laser scanning microscopy.  相似文献   
40.
In high-voltage applications, large-array n-channel lateral DMOS (LA-nLDMOS) is usually required to provide high driving capability. However, without following the foundry-suggested electrostatic discharge (ESD) design guidelines in order to reduce total layout area, LA-nLDMOS is easily damaged once the parasitic bipolar junction transistor is triggered under ESD stresses. Accordingly, the bipolar triggering of LA-nLDMOS usually limits the ESD robustness of LA-nLDMOS, particularly in the open-drain structure. In this letter, a new layout arrangement for LA-nLDMOS has been proposed to suppress the bipolar triggering under ESD stresses. Measurement results in a 0.5- ${rm mu}hbox{m}$ 16-V bipolar CMOS DMOS process have confirmed that the new proposed layout arrangement can successfully increase the human-body-model ESD level of the LA-nLDMOS with effective width of 3000 ${rm mu}hbox{m}$ from the original 0.75 kV up to 2.75 kV.   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-23

京公网安备 11010802026262号