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   318篇
  免费   14篇
电工技术   1篇
化学工业   71篇
金属工艺   9篇
机械仪表   4篇
建筑科学   27篇
能源动力   3篇
轻工业   48篇
石油天然气   1篇
无线电   19篇
一般工业技术   41篇
冶金工业   39篇
原子能技术   4篇
自动化技术   65篇
  2023年   1篇
  2022年   9篇
  2021年   14篇
  2020年   4篇
  2019年   7篇
  2018年   13篇
  2017年   4篇
  2016年   10篇
  2015年   8篇
  2014年   12篇
  2013年   31篇
  2012年   20篇
  2011年   21篇
  2010年   20篇
  2009年   19篇
  2008年   21篇
  2007年   8篇
  2006年   10篇
  2005年   3篇
  2004年   11篇
  2003年   7篇
  2002年   13篇
  2001年   8篇
  2000年   3篇
  1999年   6篇
  1998年   12篇
  1997年   11篇
  1996年   8篇
  1995年   3篇
  1994年   1篇
  1993年   4篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
  1987年   1篇
  1985年   1篇
  1980年   1篇
  1976年   2篇
  1971年   1篇
  1969年   1篇
排序方式: 共有332条查询结果,搜索用时 15 毫秒
81.
Wearables as medical technologies are becoming an integral part of personal analytics, measuring physical status, recording physiological parameters, or informing schedule for medication. These continuously evolving technology platforms do not only promise to help people pursue a healthier life style, but also provide continuous medical data for actively tracking metabolic status, diagnosis, and treatment. Advances in the miniaturization of flexible electronics, electrochemical biosensors, microfluidics, and artificial intelligence algorithms have led to wearable devices that can generate real‐time medical data within the Internet of things. These flexible devices can be configured to make conformal contact with epidermal, ocular, intracochlear, and dental interfaces to collect biochemical or electrophysiological signals. This article discusses consumer trends in wearable electronics, commercial and emerging devices, and fabrication methods. It also reviews real‐time monitoring of vital signs using biosensors, stimuli‐responsive materials for drug delivery, and closed‐loop theranostic systems. It covers future challenges in augmented, virtual, and mixed reality, communication modes, energy management, displays, conformity, and data safety. The development of patient‐oriented wearable technologies and their incorporation in randomized clinical trials will facilitate the design of safe and effective approaches.  相似文献   
82.
For manufacturing firms, the integration of advanced services into their customer offerings has become a crucial decision. Such commercial decisions require weighting the risks and rewards of implementing a business model based on advanced services. While academic experts acknowledge uncertainty of returns on investment despite potential advantages, research generally fails to address the challenge of calculating the actual risks involved in ‘servitization’. This paper seeks better understanding of managers’ risk perception and of servitization implications for strategic partnerships and network positioning, while considering the impact of factors such as entry barriers, technological knowledge and position in the supply chain (SC). Qualitative evidence is drawn from an industrial case study involving firms in the UK’s road transport industry: 14 in-depth interviews with senior executives from seven companies (manufacturers, operators, technology providers). During interviews, a payment card exercise measured risk perception and willingness to take strategic ‘make-or-buy’ decisions. Results suggest that implementing advanced services is perceived as a high-risk strategy, especially when firms lack in-house technological knowledge. However, collaborative strategic partnerships within supply chain networks can mitigate this risk and prove crucial to building entry barriers against external competitors. Based on these findings, implications for network positioning are developed.  相似文献   
83.
Fourier-based maximum entropy method in stochastic dynamics   总被引:1,自引:0,他引:1  
As the recent research by Tr

bicki and Sobczyk has demonstrated the principle of maximum entropy is a powerful tool for solving stochastic differential equations. In particular, its use in connection with the moment equations generated by the Ito formula provides accurate estimations of the probability density evolution of some oscillators for which conventional methods such as the diverse closure schemes are not applicable. A major computational requirement of the method, however, lies in the need of calculating a large number of multidimensional integrals at each time step--a numerical task for which both accurate and economic algorithms are required. In this paper it is shown that conventional economic integration techniques often lead to numerical collapse of the solution, especially when dealing with highly nonlinear oscillators. A strategy that overcomes this difficulty is proposed. In essence, the integrals are reformulated in terms of multidimensional Fourier transforms, which are solved by an ad hoc FFT algorithm aimed at obtaining only one single “frequency” point. It is demonstrated that the numerical stability and the accuracy of the proposed algorithm are superior to those afforded by other integration schemes.  相似文献   
84.
85.
Abstract. Computing the Delaunay triangulation of n points requires usually a minimum of Ω(n log n) operations, but in some special cases where some additional knowledge is provided, faster algorithms can be designed. Given two sets of points, we prove that, if the Delaunay triangulation of all the points is known, the Delaunay triangulation of each set can be computed in randomized expected linear time.  相似文献   
86.
This paper proposes the direct connection of different configurations of resistive sensor bridges to a microcontroller without any intermediate active component. Such a direct interface circuit relies on measuring the discharging time of a RC network that includes the resistances of the sensor bridge. For quarter-, half-, and full-bridge circuits, we combine the discharging times to estimate the fractional resistance change x of the bridge arms. Experimental results for half- and full-bridge circuits emulated by resistors yield a nonlinearity error below 0.3%FSR (full-scale range) for x between 0 and 0.1 and an effective resolution of 11 bit. Measurements on two commercial magnetoresistive sensors yield higher nonlinearity errors: 1.8%FSR for an AMR (Anisotropic Magnetoresistive) sensor and 5.8%FSR for a GMR (Giant Magnetoresistive) sensor, which are mainly due to the nonlinearity of the sensors themselves. Therefore, the nonlinearity of the measurement is limited by the sensors, not by the proposed interface circuit and linearisation algorithm.  相似文献   
87.
88.
In this study, composites of unsaturated polyester resin (UPR), synthesized from recycled polyethylene terephthalate (PET), with 10 to 40% in volume of corn straw fiber (CSF), were elaborated and studied the effect of fiber content on their physical and mechanical properties. The content of cellulose (48.97%), hemicellulose (24.06%), and lignin (6.59%) were determined by chemical characterization of CSF. The characteristic bonds of the UPR were identified as a cross-linking network between the styrene monomer (ST) and the unsaturated polyester (UP) through FTIR. Two decomposition stages were observed by TGA–DTG. The results of physical and mechanical properties showed that as the fiber content increased in the UPR, the water absorption increased (0.6% to 2.56%), on the other hand, the density (1218.23 to 1150.28 kg/m3), flexural strength (50.58 to 26.98 MPa), flexural modulus (2.66 to 2.29 GPa), tensile strength (8.62 to 3.65 MPa), tensile modulus (1.18 to 0.43 GPa), and hardness (81.67 to 65.67 Shore D), they decreased. SEM analysis showed some defects in the fiber distribution in the UPR, which affected the mechanical properties of the composites. This research contributes to the development of new material from use of two waste materials for the benefit of the environment.  相似文献   
89.
Noise properties in nanoscale devices are studied extending, via quantum trajectories, the classical particle Monte Carlo techniques to devices in which quantum non-local effects are important. This approach can be used to study noise in a wide range of frequencies and can also be easily coupled to a Poisson solver to study long range Coulomb effects in noise characteristics. As a numerical example, we have studied noise in a tunneling barrier showing that the results obtained within our approach exactly reproduce those of the standard Landauer-Buttiker formalism in the zero frequency limit.  相似文献   
90.
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