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   464篇
  免费   5篇
电工技术   31篇
化学工业   61篇
金属工艺   3篇
机械仪表   4篇
建筑科学   21篇
能源动力   27篇
轻工业   68篇
水利工程   7篇
武器工业   1篇
无线电   58篇
一般工业技术   51篇
冶金工业   29篇
原子能技术   2篇
自动化技术   106篇
  2024年   2篇
  2023年   3篇
  2022年   9篇
  2021年   12篇
  2020年   8篇
  2019年   11篇
  2018年   13篇
  2017年   14篇
  2016年   11篇
  2015年   9篇
  2014年   16篇
  2013年   34篇
  2012年   30篇
  2011年   24篇
  2010年   28篇
  2009年   36篇
  2008年   30篇
  2007年   28篇
  2006年   18篇
  2005年   16篇
  2004年   13篇
  2003年   14篇
  2002年   9篇
  2001年   6篇
  2000年   2篇
  1999年   9篇
  1998年   14篇
  1997年   11篇
  1996年   8篇
  1995年   4篇
  1994年   2篇
  1993年   2篇
  1990年   3篇
  1989年   3篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1980年   1篇
  1977年   1篇
  1974年   1篇
  1973年   2篇
  1971年   1篇
排序方式: 共有469条查询结果,搜索用时 15 毫秒
171.
Petros Grafias 《Water research》2010,44(9):2773-2780
A hybrid process comprising biological degradation in a vertical-flow constructed wetland (CW) and electrochemical oxidation over boron-doped diamond electrodes to decolorize, mineralize and detoxify a leachate from olive pomace processing (OPL) was investigated. Two alternative treatment schemes were compared: According to the first treatment scheme, OPL was treated by electrochemical oxidation followed by treatment in a constructed wetland pilot unit (CW-A). The second scheme comprised of treatment in a constructed wetland followed by electrochemical treatment (CW-B). The constructed wetlands units were planted with Phragmites australis (reeds) and were fed intermittently at organic loadings between 5 and 15 g COD m−2 d−1 and a residence time of 3 d. Electrochemical oxidation (EO) was performed for 360 min at 20 A.Treatment of OPL in the wetland at 15 g COD m−2 d−1 led to mean COD and color reduction of 86% and 77%, respectively; the wetland effluent with a COD of about 800 mg L−1 was polished electrochemically for 360 min after which the overall COD and color removal of the combined process (i.e. CW-B/EO) was around 95%, while the final effluent was not toxic against the marine bacteria Vibrio fischeri.Electrochemical oxidation of the original OPL at COD values between 6250 and 14 100 mg L−1 led to moderate COD and color reduction (i.e. less than 40%) through zero order kinetics. When this was coupled to constructed wetland post-treatment (i.e. EO/CW-A), the overall COD and color removal was 81% and 58%, respectively. The decreased efficiency may be assigned to the increased toxicity of the electrochemically treated effluent which was only partially removed in the natural treatment system.  相似文献   
172.
Dependent multiple cue integration for robust tracking   总被引:1,自引:0,他引:1  
We propose a new technique for fusing multiple cues to robustly segment an object from its background in video sequences that suffer from abrupt changes of both illumination and position of the target. Robustness is achieved by the integration of appearance and geometric object features and by their estimation using Bayesian filters, such as Kalman or particle filters. In particular, each filter estimates the state of a specific object feature, conditionally dependent on another feature estimated by a distinct filter. This dependence provides improved target representations, permitting to segment it out from the background even in non-stationary sequences. Considering that the procedure of the Bayesian filters may be described by a "hypotheses generation--hypotheses correction" strategy, the major novelty of our methodology compared to previous approaches is that the mutual dependence between filters is considered during the feature observation, i.e, into the "hypotheses correction" stage,instead of considering it when generating the hypotheses. This proves to be much more effective in terms of accuracy and reliability. The proposed method is analytically justified and applied to develop a robust tracking system that adapts online and simultaneously the color space where the image points are represented, the color distributions, the contour of the object and its bounding box. Results with synthetic data and real video sequences demonstrate the robustness and versatility of our method.  相似文献   
173.
Tissue P systems (tPS) represent a class of P systems in which cells are arranged in a graph rather than a hierarchical structure. On the other hand, communicating X-machines (XMs) are state-based machines, extended with a memory structure and transition functions instead of simple inputs, which communicate via message passing. One could use communicating XMs to create models built out of components in a rather intuitive way. There are investigations showing how various classes of P systems can be modelled as communicating XMs. In this paper, we define a set of principles to transform communicating XMs into tPS. We describe the rules that govern such transformations, present an example to demonstrate the feasibility of this approach and discuss ways to extend it to more general models, such as population P systems, which involve dynamic structures.  相似文献   
174.
In this paper a new Network Exterior Point Simplex Algorithm (NEPSA) for the Minimum Cost Network Flow Problem (MCNFP) is analytically presented. NEPSA belongs to a special simplex type category and is a modification of the classical network simplex algorithm. The main idea of the algorithm is to compute two flows. One flow is basic but not always feasible and the other is feasible but not always basic. A complete proof of correctness for the proposed algorithm is also presented. Moreover, the computational behavior of NEPSA is shown by an empirical study carried out for randomly generated sparse instances created by the well-known GRIDGEN network problem generator.  相似文献   
175.
In this paper we consider signal reconstruction over communication network channels that can be modeled as input switching systems. Such systems can be associated with a variety of applications including control and estimation over networks. In particular, we formulate the signal reconstruction problem as a prototypical model matching problem where the various mappings involved belong to a class of input switching systems. The design interest is placed on minimizing the worst case or stochastic average performance of this model matching system over all possible switchings with an H2 norm as the performance criterion. This minimization is performed over all stable receivers R in the class of input switching systems. For the particular setup at hand, and in the case of matched switching, two convergent sequences to the optimal solution from above and below respectively are formulated in terms of quadratic programs. An approximate solution with any a priori given precision is possible by finite truncation. Also, it is shown that in the cases of arbitrary, partially matched or unmatched switching, the optimal receiver R need not depend on the switching sequence and that it can be obtained as a linear time-invariant solution to an associated H2 norm optimization.  相似文献   
176.
Consumer Electronics devices are becoming network enabled, and along with smart phones and personal computers, they are all interconnected in home networks with broadband Internet connectivity. This sets the opportunity of making the home network, its devices and content accessible from the Internet, allowing the home owners to remotely access their connected home any time, any place, using any device. This paper provides a holistic overview of the “Remote Acces” topic, presenting all the problems and issues that make it challenging in different contexts, and most importantly analyzing six techniques and methods for enabling the remote access scenarios. It is a guide created by the combination of scientific research, extensive industrial experiences and first hand participation in relevant standardization activities.  相似文献   
177.
We present a framework to study the microeconomic effects in a reputation brokered Agent mediated Knowledge Marketplace, when we introduce dynamic pricing algorithms. We study the market with computer simulations of multiagent interactions. In this marketplace, the seller reputations are updated in a collaborative fashion based on the performance of the user in the delegated tasks. To the best of our knowledge this is the first agent mediated marketplace where the agents use dynamic pricing based on dynamically updated reputations. The framework can be used to investigate the different equilibria reached, based on the level of intelligence of the selling agents, the level of price-importance elasticity of the buying agents, and the level of unemployment in the marketplace. Preliminary experiments addressing these issues are presented.  相似文献   
178.
In this work, we formulate the interaction between image segmentation and object recognition in the framework of the Expectation-Maximization (EM) algorithm. We consider segmentation as the assignment of image observations to object hypotheses and phrase it as the E-step, while the M-step amounts to fitting the object models to the observations. These two tasks are performed iteratively, thereby simultaneously segmenting an image and reconstructing it in terms of objects. We model objects using Active Appearance Models (AAMs) as they capture both shape and appearance variation. During the E-step, the fidelity of the AAM predictions to the image is used to decide about assigning observations to the object. For this, we propose two top-down segmentation algorithms. The first starts with an oversegmentation of the image and then softly assigns image segments to objects, as in the common setting of EM. The second uses curve evolution to minimize a criterion derived from the variational interpretation of EM and introduces AAMs as shape priors. For the M-step, we derive AAM fitting equations that accommodate segmentation information, thereby allowing for the automated treatment of occlusions. Apart from top-down segmentation results, we provide systematic experiments on object detection that validate the merits of our joint segmentation and recognition approach.  相似文献   
179.
180.
The Itanium processor cartridge is a packaging optimization for electrical and thermal performance in a server environment. The 3-in. x 5-in. cartridge contains the Itanium CPU, up to 4 megabytes of level-3 (L3) cache, an innovative power delivery scheme, and an integrated vapor chamber thermal spreading lid for removing power. Cartridges and a chip set can be ganged electrically by means of a glueless bidirectional, multidrop system bus. Power is delivered through a custom connection with separate voltages for the 0.18-micron CPU and 0.25-micron custom cache devices. An I2C serial connection provides access to system management features such as temperature monitoring and cartridge identification information  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