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   3988篇
  免费   142篇
  国内免费   4篇
电工技术   79篇
综合类   6篇
化学工业   986篇
金属工艺   66篇
机械仪表   68篇
建筑科学   299篇
矿业工程   17篇
能源动力   78篇
轻工业   609篇
水利工程   23篇
石油天然气   11篇
无线电   259篇
一般工业技术   529篇
冶金工业   555篇
原子能技术   27篇
自动化技术   522篇
  2021年   48篇
  2020年   39篇
  2019年   52篇
  2018年   52篇
  2017年   41篇
  2016年   87篇
  2015年   74篇
  2014年   134篇
  2013年   188篇
  2012年   172篇
  2011年   152篇
  2010年   147篇
  2009年   167篇
  2008年   171篇
  2007年   150篇
  2006年   170篇
  2005年   130篇
  2004年   122篇
  2003年   109篇
  2002年   62篇
  2001年   55篇
  2000年   65篇
  1999年   56篇
  1998年   86篇
  1997年   64篇
  1996年   46篇
  1995年   35篇
  1994年   53篇
  1993年   46篇
  1992年   41篇
  1991年   42篇
  1990年   45篇
  1989年   45篇
  1988年   41篇
  1987年   53篇
  1986年   35篇
  1985年   56篇
  1984年   60篇
  1983年   41篇
  1982年   34篇
  1981年   45篇
  1980年   52篇
  1979年   41篇
  1978年   39篇
  1977年   51篇
  1976年   52篇
  1975年   33篇
  1974年   40篇
  1973年   32篇
  1971年   29篇
排序方式: 共有4134条查询结果,搜索用时 46 毫秒
1.
Objective: This study examined whether disruption of performance is moderated in Parkinson's disease (PD) patients who acquire their motor behaviors in an implicit manner. Method: Twenty-seven patients with PD learned a hammering task in errorless (implicit) or errorful (explicit) conditions and were tested for robustness of motor performance under a secondary task load, which required them to continuously count backward as they performed the hammering task. Results: Patients in the errorless (implicit) motor learning condition exhibited robustness to secondary task loading, whereas patients in the errorful (explicit) motor learning condition did not. Conclusions: Implicit motor learning techniques should be considered by PD rehabilitation specialists in cases in which existing disruption to movements is exacerbated by conscious control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
2.
This article proposes a model of the ways in which dyadic interactions between employees who occupy 1 of 4 archetypal social roles in organizations can lead to either episodic or institutionalized patterns of victimization. The model shows how the occurrence of victimization involving these 4 role types is influenced by organizational variables such as power differences, culture, and access to social capital. The model integrates behavioral and social structural antecedents of victimization to develop a relational perspective on the dynamics of harmful behavior in the workplace. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
3.
PURPOSE: We designed a phase I-II trial of three active agents, paclitaxel, ifosfamide, and vinorelbine, in advanced non-small-cell lung cancer (NSCLC) to: 1) define the dose-limiting toxicities (DLT) and maximum tolerated dose (MTD) of paclitaxel with filgrastim (G-CSF) support; and 2) determine the overall response rate and median survival of patients treated on this regimen. PATIENTS AND METHODS: We treated cohorts of patients with stage IIIB or IV NSCLC with ifosfamide 1.2-1.6 g/m2/day x 3 and vinorelbine 20-25 mg/m2/day x 3 and escalating doses of paclitaxel at 100-175 mg/m2 on day 2 with G-CSF support on a 21-day cycle. One prior experimental single-agent chemotherapy regimen was allowed. RESULTS: Fifty-six patients, were enrolled on this trial: 27 on the phase I portion of the study and an additional 29 at the recommended phase II dose (RPTD). Thirteen patients had received prior chemotherapy. Paclitaxel doses of 175 mg/m2 and 150 mg/m2 produced dose-limiting myelosuppression, and the RPTD was determined to be paclitaxel 135 mg/m2 with ifosfamide 1.2 g/m2/day on days 1-3 and vinorelbine 20 mg/m2/ day on days 1-3 with G-CSF support. The overall response rate was 18%, with a median survival of 6.1 months. Six of 35 patients (17%) treated at the RPTD achieved a partial response to therapy. Grade IV neutropenia was observed in 19 of 35 patients at this dose, with eight patients suffering febrile neutropenia. CONCLUSIONS: This non-cisplatin-containing three-drug regimen has substantial toxicity and low activity in advanced NSCLC, and does not seem to improve on prior regimens. It is unclear whether the lack of efficacy relates to an antagonistic reaction between the specific drugs, administration schedule, or to subtherapeutic doses of the individual agents.  相似文献   
4.
„Patriot“     
Ohne Zusammenfassung  相似文献   
5.
当今,从事OC-48、OC-192技术的设计师在设计基于因特网协议(IP协议)的下一代系统时,因系统含有诸如ASIC、网络处理器(NP)、高速跟踪器等元件,以及分组SONET物理层(PoS-PHY)接口规范等的演变,而一直面临挑战。抖动和扭斜失真等现象的存在给诸如系统分组接口第4层(SPI-4)和通用交换接口(CSIX)等总线结构本已拥挤的时序容限,以及四元数据率静态RAM传送表访问时间带来极大混乱。再加上诸如低压差分信号(LVDS)、高速收发逻辑和短线串行终端逻辑等超低电压峰-峰信号技术的引入,使数据出错的可能性变得异常之高。而利用仿真技…  相似文献   
6.
A new approach based on catalytic distillation (CD) technology was proposed to remove water from ethanol. Isobutylene was introduced to react with water in the CD column. The commercial software simulation tool Aspen Plus was used to investigate the effects of key design factors such as operating pressure and temperature, reactant ratios, reflux and distillate to feed ratios, number of separation and reaction stages, and feed and reaction zone location. It was found that the CD technology offers potential advantages of reduced energy consumption and reduced capital cost over traditional approaches for the removal of water from ethanol.  相似文献   
7.
8.
Ohne ZusammenfassungMitteilung aus der staatlichen Untersuchungsanstalt für Lebensmittel in Graz.  相似文献   
9.
10.
Measuring techniques for characterizing gas/liquid reactors . The article considers measuring techniques for the characterization of the phases in gas/liquid reactors. These include the velocity profile and turbulence in the continuous phase as well as holdup, size, and velocity of the dispersed phase. Also, methods for the determination of the specific interfacial area and the volumetric mass transfer coefficients are discussed. Measuring methods have made enormous advances in recent years. In spite of this, there is a lack of reliable methods, especially for use during reactions without disturbing the state of the reactor. It is suspected that probe technique will gradually fall into disuse and more and more attention will be focussed on contractless methods. This calls for further development of ultrasonic methods and methods relying on emission of light.  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