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   2822篇
  免费   204篇
  国内免费   16篇
电工技术   51篇
综合类   18篇
化学工业   738篇
金属工艺   67篇
机械仪表   42篇
建筑科学   143篇
矿业工程   7篇
能源动力   134篇
轻工业   137篇
水利工程   15篇
石油天然气   7篇
无线电   279篇
一般工业技术   633篇
冶金工业   136篇
原子能技术   15篇
自动化技术   620篇
  2024年   7篇
  2023年   61篇
  2022年   124篇
  2021年   160篇
  2020年   110篇
  2019年   108篇
  2018年   109篇
  2017年   122篇
  2016年   138篇
  2015年   102篇
  2014年   162篇
  2013年   194篇
  2012年   211篇
  2011年   227篇
  2010年   141篇
  2009年   149篇
  2008年   128篇
  2007年   105篇
  2006年   85篇
  2005年   43篇
  2004年   47篇
  2003年   49篇
  2002年   41篇
  2001年   32篇
  2000年   23篇
  1999年   28篇
  1998年   44篇
  1997年   25篇
  1996年   16篇
  1995年   21篇
  1994年   12篇
  1993年   11篇
  1992年   18篇
  1991年   20篇
  1990年   16篇
  1989年   6篇
  1988年   5篇
  1987年   8篇
  1985年   10篇
  1984年   7篇
  1983年   12篇
  1981年   10篇
  1979年   9篇
  1978年   7篇
  1976年   12篇
  1975年   8篇
  1974年   10篇
  1973年   8篇
  1972年   9篇
  1962年   4篇
排序方式: 共有3042条查询结果,搜索用时 0 毫秒
31.
32.
Integrating products and services to customized solutions can help firms to differentiate from their competitors. In practice, however, various companies fall short in extracting value from their customers. Therefore this paper focuses on pricing aspects as central means for value appropriation in the context of solutions. Following the resource-based view of the firm, we adopt a process-oriented perspective on pricing practices in order to identify crucial factors and activities. Based on 15 in-depth interviews with practitioners from various industries we derive six steps of a price management process for value appropriation in the context of solution selling and present critical activities and routines within each step.  相似文献   
33.
Although IP Multimedia Subsystem (IMS) based Next Generation Networks (NGNs) are already emerging as the common session control platform for converging fixed, mobile and cable networks, harmonized solutions for the management of these converged platforms have still got to be developed. This document describes a hands-on approach to NGN Management. Started with IMS specific management systems, succeeding research had to take into account the importance of the management of NGN SDPs as well. This work shows that the hybrid nature of an NGN, where services can be delivered at the IMS layer, by SIP signaling mechanisms, as well as at the SDP, via Web Services, requires a harmonized management approach. Taking into account Service Oriented Architecture (SOA) principles and policy based model driven architectures, this work shows that a unification of service composition and service management already at the workflow creation level, bares significant benefits in terms of automation and harmonization. Following the SOA paradigm, the approach presented here does not differentiate between business process management (BPM) and management process management. Focusing on Telemanagement Forum’s enhanced Telecom Operations Map service fulfillment and service assurance operations, this document describes an New Generation Software and Services (NGOSS) based implementation of a unified Operation Support System (OSS) for NGNs that encompasses many problems of former stovepipe management solutions in terms of automation, flexibility and manageability.  相似文献   
34.
Medical data mining is currently actively pursued in computer science and statistical research but not in medical practice. The reasons therefore lie in the difficulties of handling and statistically analyzing medical data. We have developed a system that allows practitioners in the field to interactively analyze their data without assistance of statisticians or data mining experts. In the course of this paper we will introduce data mining of medical data and show how this can be achieved for survival data. We will demonstrate how to solve common problems of interactive survival analysis by presenting the Online Clinical Data Mining (OCDM) system. Thereby the main focus is on similarity based queries, a new method to select similar cases based on their covariables and the influence of these on their survival.  相似文献   
35.
The current Web Services Agreement specification draft proposes a simple request-response protocol for agreement creation only addressing bilateral offer exchanges. This paper proposes a framework augmenting this WS-Agreement to enable negotiations according to a variety of bilateral and multilateral negotiation protocols. The framework design is based on a thorough analysis of taxonomies for negotiations from the literature in order to allow for capturing a variety of different negotiation models within a single, WS-Agreement compatible, framework. In order to provide for the intended flexibility, the proposed protocol takes a two-stage approach: a meta-protocol is conducted among interested parties to agree on a common negotiation protocol first before the real negotiation is carried out in the second step due to the protocol established in the first step.  相似文献   
36.
Femtosecond pulses of a passive mode-locked Rhodamine-6G dye laser are amplified in a double-stage, three-pass, plane mirror, Sulforhodamine-101 amplifier system. Saturable filters (Schott glass RG645 and Malachite Green) are used to suppress amplified spontaneous emission. Input pulses of 110-fs duration are broadened to 240 fs in the amplifier system and recompressed to 75 fs in a prism-pair compressor. Using a 20-Hz Q-switched Nd:YAG pump laser of 50-mJ second-harmonic output energy, we obtained amplified and recompressed pulses of 180-μJ energy at 625 nm starting with 40-pJ input pulses. The small-signal amplification dynamics is studied numerically. Relevant gain dye and saturable filter parameters are derived. The influence of amplified spontaneous emission is analyzed.  相似文献   
37.
Tagging, tracking, or validation of products are often facilitated by inkjet-printed optical information labels. However, this requires thorough substrate pretreatment, ink optimization, and often lacks in printing precision/resolution. Herein, a printing method based on laser-driven deposition of solid polymer ink that allows for printing on various substrates without pretreatment is demonstrated. Since the deposition process has a precision of <1 µm, it can introduce the concept of sub-positions with overlapping spots. This enables high-resolution fluorescent labels with comparable spot-to-spot distance of down to 15 µm (444,444 spots cm−2) and rapid machine learning-supported readout based on low-resolution fluorescence imaging. Furthermore, the defined thickness of the printed polymer ink spots can be used to fabricate multi-channel information labels. Additional information can be stored in different fluorescence channels or in a hidden topography channel of the label that is independent of the fluorescence.  相似文献   
38.
Real-Time Systems - This paper presents results and observations from a survey of 120 industry practitioners in the field of real-time embedded systems. The survey provides insights into the...  相似文献   
39.
40.
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