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   791篇
  免费   81篇
  国内免费   3篇
电工技术   5篇
综合类   1篇
化学工业   236篇
金属工艺   8篇
机械仪表   29篇
建筑科学   34篇
矿业工程   6篇
能源动力   18篇
轻工业   258篇
水利工程   6篇
石油天然气   11篇
无线电   25篇
一般工业技术   105篇
冶金工业   55篇
自动化技术   78篇
  2024年   2篇
  2023年   12篇
  2022年   36篇
  2021年   60篇
  2020年   40篇
  2019年   48篇
  2018年   35篇
  2017年   35篇
  2016年   43篇
  2015年   39篇
  2014年   47篇
  2013年   68篇
  2012年   46篇
  2011年   80篇
  2010年   35篇
  2009年   39篇
  2008年   27篇
  2007年   28篇
  2006年   15篇
  2005年   21篇
  2004年   9篇
  2003年   14篇
  2002年   9篇
  2001年   6篇
  2000年   4篇
  1999年   3篇
  1998年   17篇
  1997年   7篇
  1996年   8篇
  1995年   4篇
  1994年   5篇
  1993年   4篇
  1992年   3篇
  1991年   1篇
  1990年   2篇
  1989年   4篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1982年   1篇
  1981年   3篇
  1976年   2篇
  1975年   3篇
  1974年   2篇
  1971年   1篇
  1968年   1篇
排序方式: 共有875条查询结果,搜索用时 15 毫秒
1.
2.
This study aimed to evaluate the physicochemical characteristics and sensory attributes of beef burgers with the addition of pea fibre as a partial substitute of meat or fat. Three formulations were prepared: control (CON) – similar to the commercial formulation; fibre/less meat (FLM)—5% meat reduction and addition of 1% pea fibre; fibre/less fat (FLF)—7% fat reduction and addition of 1% pea fibre. Non-significant differences were obtained for pH, colour parameters (L* and b*), texture profile, cooking loss and size reduction among formulations. Moreover, sensory analysis with consumers of beef burgers did not indicate differences among the formulations for all the analysed attributes. Therefore, pea fibre is a promising partial replacer for meat and fat in beef burgers due to the preservation of technological parameters and sensory acceptance.  相似文献   
3.
4.
Personal and Ubiquitous Computing - This article presents a study concerning the evaluation of a smart home control system for elderly people with a sample of 10 users in a city in the interior of...  相似文献   
5.
The complex tissue-specific physiology that is orchestrated from the nano- to the macroscale, in conjugation with the dynamic biophysical/biochemical stimuli underlying biological processes, has inspired the design of sophisticated hydrogels and nanoparticle systems exhibiting stimuli-responsive features. Recently, hydrogels and nanoparticles have been combined in advanced nanocomposite hybrid platforms expanding their range of biomedical applications. The ease and flexibility of attaining modular nanocomposite hydrogel constructs by selecting different classes of nanomaterials/hydrogels, or tuning nanoparticle-hydrogel physicochemical interactions widely expands the range of attainable properties to levels beyond those of traditional platforms. This review showcases the intrinsic ability of hybrid constructs to react to external or internal/physiological stimuli in the scope of developing sophisticated and intelligent systems with application-oriented features. Moreover, nanoparticle-hydrogel platforms are overviewed in the context of encoding stimuli-responsive cascades that recapitulate signaling interplays present in native biosystems. Collectively, recent breakthroughs in the design of stimuli-responsive nanocomposite hydrogels improve their potential for operating as advanced systems in different biomedical applications that benefit from tailored single or multi-responsiveness.  相似文献   
6.
The gamma aminobutyric acid-A (GABAA) agonist, muscimol, the glutamate N-methyl-D-aspartate (NMDA) receptor antagonist, D-2-amino-5-phosphonopentanoic acid (AP5), and the inhibitor of the extracellularly regulated kinases (ERKs), UO 126, cause retrograde amnesia when administered to the hippocampus. In the present study, the authors found that they all cause retrograde amnesia for 1-trial inhibitory avoidance, not only when infused into the dorsal CA1 region of the hippocampus, but also when infused into the basolateral amygdala or the entorhinal, parietal, and posterior cingulate cortices. The posttraining time course of the effect of each drug was, however, quite different across brain structures. Thus, in all of them, NMDA receptors and the ERK pathway are indispensable for memory consolidation, and GABAA receptor activation inhibits memory consolidation: but in each case, their influence is interwoven differently. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
7.
8.
This work deals with the rheological, morphological, and thermal properties of composites having poly(ethylene terephthalate) (PET), polyamide-6 (PA6), and their blends as matrices, and rice husk ash (RHA) as a filler. The study determines the effect of composition on the change in viscosity and rate of degradation during processing in a torque rheometer. Our data indicates that thermal stability and degradation during processing depend on matrix composition and filler concentration. SEM micrographs show both partial adhesion of the filler to the matrices and filler pullout. Optical microscopy shows particle agglomeration and that agglomerate size increased with filler content. FTIR investigates the shifting of absorption bands of PET/PA6 composite after the addition of RHA and attributes the selective dispersion of RHA to the formation of hydrogen bonds. Our data supports the idea that filler employed here is an option to develop polymer composites with improved properties.  相似文献   
9.
This work aims to investigate the effect of adding vulcanized or partially devulcanized rubbers on recycled polypropylene (PPr), considering thermomechanical and morphological properties. The study proposes to better understand how structural changes underwent by rubber (after the devulcanization) contributed to improving the mechanical properties of the PPr. The PPr/rubber blends were prepared by a co-rotating twin-screw extruder and then were injected. The blends composed of the most devulcanized rubbers by microwaves with refined microstructure showed higher values of elongation at break and toughness. Data showed that the devulcanization process applied to the rubber interfered positively in its adhesion to the PPr. Data from dynamic mechanical analysis and atomic force microscopy indicated that the most devulcanized rubbers presented an interface more connected to PPr. These chemical interactions possibly impacted the mechanical properties of the PPr. Moreover, dilatation processes favored the fracture mechanisms of the PPr when rubber was added to it.  相似文献   
10.
In classical deterministic scheduling problems, it is assumed that all jobs have to be processed. However, in many practical cases, mostly in highly loaded make-to-order production systems, accepting all jobs may cause a delay in the completion of orders which in turn may lead to high inventory and tardiness costs. Thus, in such systems, the firm may wish to reject the processing of some jobs by either outsourcing them or rejecting them altogether. The field of scheduling with rejection provides schemes for coordinated sales and production decisions by grouping them into a single model. Since scheduling problems with rejection are very interesting both from a practical and a theoretical point of view, they have received a great deal of attention from researchers over the last decade. The purpose of this survey is to offer a unified framework for offline scheduling with rejection by presenting an up-to-date survey of the results in this field. Moreover, we highlight the close connection between scheduling with rejection and other fields of research such as scheduling with controllable processing times and scheduling with due date assignment, and include some new results which we obtained for open problems.  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