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   234篇
  免费   22篇
  国内免费   1篇
电工技术   2篇
化学工业   88篇
金属工艺   5篇
机械仪表   4篇
建筑科学   7篇
能源动力   10篇
轻工业   56篇
水利工程   1篇
无线电   15篇
一般工业技术   31篇
冶金工业   7篇
原子能技术   2篇
自动化技术   29篇
  2024年   4篇
  2023年   5篇
  2022年   7篇
  2021年   11篇
  2020年   11篇
  2019年   10篇
  2018年   15篇
  2017年   17篇
  2016年   9篇
  2015年   10篇
  2014年   9篇
  2013年   29篇
  2012年   18篇
  2011年   24篇
  2010年   11篇
  2009年   8篇
  2008年   8篇
  2007年   9篇
  2006年   12篇
  2005年   6篇
  2004年   7篇
  2003年   1篇
  2002年   2篇
  2000年   1篇
  1999年   4篇
  1998年   1篇
  1996年   1篇
  1995年   1篇
  1990年   1篇
  1989年   1篇
  1982年   1篇
  1979年   1篇
  1976年   1篇
  1975年   1篇
排序方式: 共有257条查询结果,搜索用时 531 毫秒
51.
Blood glucose control is an essential goal for the patients who have Type‐1 diabetes (T1D). The prediction of the blood glucose levels for the next 30‐minute is crucial. If the predicted blood glucose level is in the critical ranges, and these predictions can be known in advance, then the patients can take the necessary cautions to prevent from it. In this article, we propose a modified fuzzy particle swarm optimization algorithm for the prediction of blood glucose levels of 30‐minute after the last measurement. We form the average and patient‐specific models to predict the blood glucose level of the patients. Both models are tested on two different datasets which contain patients with T1D. The experimental results are evaluated in terms of root mean squared error and Clarke error grid analysis metrics. The results indicate that our proposed modified algorithm is feasible to be applied to the prediction of blood glucose levels. In addition, this approach can assist patients with T1D for their blood glucose control.  相似文献   
52.
The radical‐initiated terpolymerization of 3,4‐dihydro‐2H‐pyran (DHP), maleic anhydride (MA), and vinyl acetate (VA), which were used as a donor–acceptor–donor system, was carried out in methyl ethyl ketone in the presence of 2,2′‐azobisisobutyronitrile as an initiator at 65°C in a nitrogen atmosphere. The synthesis and characterization of binary and ternary copolymers, some kinetic parameters of terpolymerization, the terpolymer‐composition/thermal‐behavior relationship, and the antitumor activity of the synthesized polymers were examined. The polymerization of the DHP–MA–VA monomer system predominantly proceeded by the alternating terpolymerization mechanism. The in vitro cytotoxicities of poly(3,4‐dihydro‐2H‐pyran‐alt‐maleic anhydride) [poly(DHP‐alt‐MA)] and poly(3,4‐dihydro‐2H‐pyran‐co‐maleic anhydride‐co‐vinyl acetate) [poly(DHP‐co‐MA‐co‐VA)] were evaluated with Raji cells (human Burkitt lymphoma cell line). The antitumor activity of the prepared anion‐active poly(DHP‐alt‐MA) and poly(DHP‐co‐MA‐co‐VA) polymers were studied with methyl–thiazol–tetrazolium testing, and the 50% cytotoxic dose was calculated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2352–2359, 2005  相似文献   
53.
Summary The binary and ternary copolymers are synthesized by free-radical initiated binary copolymerization of citraconic anhydride (CA) with acrylamide (AAm) and terpolymerization of acrylamide (AAm) – citraconic anhydride (CA) – vinyl acetate (VA) monomer system. Co- and terpolymerization were carried out in the presence of benzoyl peroxide (BPO) as an initiator at 70 °C in benzene under nitrogen atmosphere. Structure and monomer unit composition of the copolymers, obtained from a wide range of monomer feed were determined by elemental analysis. Structural peculiarities of synthesized PAAm, [poly (AAm-alt-CA)] and [poly(AAm-co-CA-co-VA)] were characterized by using Fourier Transform Infrared (FTIR), Uv–vis, 1H-NMR, X-ray diffraction (XRD), elemental analysis, analytical methods (titration methods) and viscometric measurements.  相似文献   
54.
Automatic analysis of head gestures and facial expressions is a challenging research area and it has significant applications in human-computer interfaces. We develop a face and head gesture detector in video streams. The detector is based on face landmark paradigm in that appearance and configuration information of landmarks are used. First we detect and track accurately facial landmarks using adaptive templates, Kalman predictor and subspace regularization. Then the trajectories (time series) of facial landmark positions during the course of the head gesture or facial expression are converted in various discriminative features. Features can be landmark coordinate time series, facial geometric features or patches on expressive regions of the face. We use comparatively, two feature sequence classifiers, that is, Hidden Markov Models (HMM) and Hidden Conditional Random Fields (HCRF), and various feature subspace classifiers, that is, ICA (Independent Component Analysis) and NMF (Non-negative Matrix Factorization) on the spatiotemporal data. We achieve 87.3% correct gesture classification on a seven-gesture test database, and the performance reaches 98.2% correct detection under a fusion scheme. Promising and competitive results are also achieved on classification of naturally occurring gesture clips of LIlir TwoTalk Corpus.  相似文献   
55.
Public Private Partnerships (PPPs) cover a range of possible relationships between public and private parties. PPP contracts are typically used in contexts of great uncertainty, such as large construction and infrastructure projects that are realized over a longer period of time. Hence, a major challenge in PPPs is to keep construction progress cost-efficient and on schedule, under continuously changing circumstances. One way to achieve this is through clever contracting, by proactively anticipating potential change in the planning phase and providing flexible contract mechanisms that enable an effective response. The purpose of this article is to discuss potential changes and the subsequent requirement of flexibility in PPP contracts. By flexibility, we mean the ability of the contract to deal with changing circumstances. We set out to do so by studying the available literature on the subject and by analysing the case study of the Blankenburgverbinding in the Netherlands, a Design, Build, Finance and Maintain (DBFM) project that is currently in its planning phase based on 32 interviews. Our main findings are that the timely and accurate recognition of potential changes, combined with the availability of flexible coping mechanisms, provide the stakeholders with a better understanding of the challenges they face in realizing their aims in the pre-contract phase of projects. This understanding helps to better prepare a PPP contract for potential changes.  相似文献   
56.
In the context of affective human behavior analysis, we use the term continuous input to refer to naturalistic settings where explicit or implicit input from the subject is continuously available, where in a human–human or human–computer interaction setting, the subject plays the role of a producer of the communicative behavior or the role of a recipient of the communicative behavior. As a result, the analysis and the response provided by the automatic system are also envisioned to be continuous over the course of time, within the boundaries of digital machine output. The term continuous affect analysis is used as analysis that is continuous in time as well as analysis that uses affect phenomenon represented in dimensional space. The former refers to acquiring and processing long unsegmented recordings for detection of an affective state or event (e.g., nod, laughter, pain), and the latter refers to prediction of an affect dimension (e.g., valence, arousal, power). In line with the Special Issue on Affect Analysis in Continuous Input, this survey paper aims to put the continuity aspect of affect under the spotlight by investigating the current trends and provide guidance towards possible future directions.  相似文献   
57.
In recent years, neural networks have turned out as a powerful method for numerous practical applications in a wide variety of disciplines. In more practical terms neural networks are one of nonlinear statistical data modeling tools. They can be used to model complex relationships between inputs and outputs or to find patterns in data. In food technology artificial neural networks (ANNs) are useful for food safety and quality analyses, predicting chemical, functional and sensory properties of various food products during processing and distribution. In wine technology, ANNs have been used for classification and for predicting wine process conditions. This review discusses the basic ANNs technology and its possible applications in wine technology.  相似文献   
58.
BACKGROUND: The influence of methanol feed rate on recombinant human growth hormone (rhGH) production by Pichia pastoris hGH‐Mut+ in medium containing sorbitol was investigated at three different specific growth rates (µ), namely, 0.02 (MS‐0.02), 0.03 (MS‐0.03), and 0.04 (MS‐0.04). RESULTS: Increasing methanol feed rate above MS‐0.03 did not affect sorbitol consumption, showing that µ = 0.03 h?1 is a threshold limiting value, above which sorbitol utilization became independent of methanol feed rate. Moreover, when sorbitol was consumed, no further cell growth was observed. Increase in methanol feed rate triggered cell synthesis and the highest cell concentration was obtained at MS‐0.04 as 48 g L?1 (t = 18 h); whereas, the highest rhGH production, 270 mg L?1, was obtained at MS‐0.03 as a consequence of lower extracellular protease production and higher AOX activity (41 U g?1 CDW). Oxygen uptake rate increased with increasing µ, having the maximum value, 76.6 mmol m?3 s?1, at MS‐0.04. KLa had a tendency to increase with µ, having a maximum value of 0.15 s?1 at MS‐0.04 (t = 15 h). CONCLUSION: By considering rhGH concentration and oxygen transfer characteristics, the bioprocess can be improved by a two‐stage feeding strategy, operating at MS‐0.04 at the beginning of fermentation, and thereafter shifting to MS‐0.03. Copyright © 2009 Society of Chemical Industry  相似文献   
59.
60.
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