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   1639篇
  免费   70篇
  国内免费   12篇
电工技术   26篇
综合类   3篇
化学工业   353篇
金属工艺   45篇
机械仪表   57篇
建筑科学   32篇
矿业工程   2篇
能源动力   98篇
轻工业   106篇
水利工程   11篇
石油天然气   4篇
无线电   222篇
一般工业技术   368篇
冶金工业   176篇
原子能技术   18篇
自动化技术   200篇
  2023年   27篇
  2022年   71篇
  2021年   96篇
  2020年   82篇
  2019年   59篇
  2018年   93篇
  2017年   66篇
  2016年   73篇
  2015年   53篇
  2014年   63篇
  2013年   123篇
  2012年   67篇
  2011年   78篇
  2010年   66篇
  2009年   42篇
  2008年   50篇
  2007年   63篇
  2006年   33篇
  2005年   27篇
  2004年   21篇
  2003年   13篇
  2002年   26篇
  2001年   26篇
  2000年   16篇
  1999年   18篇
  1998年   42篇
  1997年   45篇
  1996年   28篇
  1995年   15篇
  1994年   17篇
  1993年   17篇
  1992年   11篇
  1991年   14篇
  1990年   8篇
  1989年   9篇
  1988年   9篇
  1987年   9篇
  1986年   12篇
  1985年   8篇
  1984年   13篇
  1983年   11篇
  1982年   6篇
  1981年   10篇
  1980年   8篇
  1979年   9篇
  1978年   9篇
  1977年   11篇
  1976年   16篇
  1974年   5篇
  1973年   5篇
排序方式: 共有1721条查询结果,搜索用时 0 毫秒
1.
The hot blow forming of magnesium sheet offers significant opportunity for forming complex, lightweight parts for automotive applications. This paper characterizes the elevated-temperature formability of AZ31 magnesium sheet materials and the effect of processing conditions on the performance of these materials. In addition, magnesium sheet application development at General Motors Corporation is reviewed.  相似文献   
2.
The application of micro- and nanofabrication processes to the development of hybrid synthetic and biological systems may enable the production of new devices such as controllable transporters, gears, levers, micropumps, or microgenerators powered by biological molecular motors. However, engineering these hybrid devices requires fabrication processes that are compatible with biological materials such as kinesin motor proteins and microtubules. In this paper, the effects of micro- and nanofabrication processing chemicals and resists on the functionality of casein, kinesin, and microtubule proteins are systematically examined to address the important missing link of the biocompatibility of micro- and nanofabrication processes needed to realize hybrid system fabrication. It is found that both casein, which is used to prevent motor denaturation on surfaces, and kinesin motors are surprisingly tolerant of most of the processing chemicals examined. Microtubules, however, are much more sensitive. Exposure to the processing chemicals leads to depolymerization, which is partially attributed to the pH of the solutions examined. When the chemicals were diluted in aqueous buffers, a subset of them no longer depolymerized microtubules and in their diluted forms still worked as resist removers. This approach broadens the application of micro- and nanofabrication processes to hybrid synthetic and biological system fabrication.  相似文献   
3.
A simple practical equivalent continuum numerical model for simulating the behavior of jointed rock mass has been extended to three-dimensional using FLAC3D. This model estimates the properties of jointed rock mass from the properties of intact rock and a joint factor (Jf), which is the integration of the properties of joints to take care of the effects of frequency, orientation, and strength of joint. A new FISH function has been written in FLAC3D specifically for modeling jointed rocks using the Duncan and Chang hyperbolic model. This model has been validated first with simple element tests at different confining pressures for different rocks with different joint configurations. Explicit modeling of the joints has also been done in element tests and results obtained compare well with the results of equivalent continuum model and also with experimental results. Further, this has been applied for a case study of a large underground power house cavern in the Himalayas. The analysis has been done under various stages of excavation, assigning a null model available in FLAC3D for simulating the excavation.  相似文献   
4.
Energy consumption is one of the important parameters to be optimized during the design of portable embedded systems. Thus, most of the contemporary portable devices feature low-power processors coupled with on-chip memories (e.g., caches, scratchpads). Scratchpads are better than traditional caches in terms of power, performance, area, and predictability. However, unlike caches they depend upon software allocation techniques for their utilization. In this paper, we present scratchpad overlay techniques which analyze the application and insert instructions to dynamically copy both variables and code segments onto the scratchpad at runtime. We demonstrate that the problem of overlaying scratchpad is an extension of the Global Register Allocation problem. We present optimal and near-optimal approaches for solving the scratchpad overlay problem. The near-optimal scratchpad overlay approach achieves close to the optimal results and is significantly faster than the optimal approach. Our approaches improve upon the previously known static allocation technique for assigning both variables and code segments onto the scratchpad. The evaluation of the approaches for ARM7 processor reports, average energy, and execution time reductions of 26% and 14% over the static approach, respectively. Additional experiments comparing the overlayed scratchpads against unified caches of the same size, report average energy, and execution time savings of 20% and 10%, respectively. We also report data memory energy reductions of 45%-57% due to the insertion of a 1024-bytes scratchpad memory in the memory hierarchy of a digital signal processor (DSP).  相似文献   
5.
Fluoroquinolones, a new class of compounds characterised by broad antimicrobial spectrum including mycobacteria together with limited toxicity, have recently been introduced in the chemotherapy of various human infectious diseases. Pefloxacin, one of the members of this class, was recently demonstrated to be bactericidal against M.leprae in the mouse foot-pad model and clinically beneficial in lepromatous leprosy patients. Clinical response to standard MDT with added pefloxacin in ten previously untreated (both PB and MB) was compared with that in ten similar patients on MDT alone in the present trial. The results of chemotherapy were quantified by a method of clinical scoring. This pilot study showed that addition of pefloxacin led to significant and rapid clinical improvement. There were no side effects attributable to pefloxacin.  相似文献   
6.
7.
The paper shows that an analytical evaluation of the power coefficient Cp for an ideal horizontal-axis wind turbine can be made via an expression giving the direct relationship of Cp and the axial induction factor a. The results obtained agree closely with those obtained numerically from the usual integral expression involving several variables.  相似文献   
8.
9.
The Journal of Supercomputing - A correction to this paper has been published: https://doi.org/10.1007/s11227-021-03790-9  相似文献   
10.
Verma  Amit  Dawar  Siddharth  Kumar  Raman  Navathe  Shamkant  Goyal  Vikram 《Applied Intelligence》2021,51(7):4649-4663

High-utility Itemset Mining (HUIM) finds patterns from a transaction database with their utility no less than a user-defined threshold. The utility of an itemset is defined as the sum of the utilities of its items. The utility notion enables a data analyst to associate a profit score with each item and thereof to a pattern. We extend the notion of high-utility with diversity to define a new pattern type called High-utility and Diverse pattern (HUD). The notion of diversity of a pattern captures the extent of the different categories covered by the selected items in the pattern. An application of diverse-pattern lies in the recommendation task where a system can recommend to a customer a set of items from a new class based on her previously bought items. Our notion of diversity is easy to compute and also captures the basic essence of a previously proposed diversity notion. The existing algorithm to compute frequent-diverse patterns is 2-phase, i.e., in the first phase, frequent patterns are computed, out of which diverse patterns are filtered out in the second phase. We, in this paper, give an integrated algorithm that efficiently computes high-utility and diverse patterns in a single phase. Our experimental study shows that our proposed algorithm is very efficient as compared to a 2-phase algorithm that extracts high-utility itemsets in the first phase and filters out the diverse itemsets in the second phase.

  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