全文获取类型
收费全文 | 1226篇 |
免费 | 80篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 10篇 |
化学工业 | 357篇 |
金属工艺 | 7篇 |
机械仪表 | 23篇 |
建筑科学 | 65篇 |
矿业工程 | 2篇 |
能源动力 | 25篇 |
轻工业 | 194篇 |
水利工程 | 13篇 |
石油天然气 | 2篇 |
无线电 | 40篇 |
一般工业技术 | 233篇 |
冶金工业 | 183篇 |
原子能技术 | 6篇 |
自动化技术 | 147篇 |
出版年
2023年 | 14篇 |
2022年 | 47篇 |
2021年 | 59篇 |
2020年 | 33篇 |
2019年 | 38篇 |
2018年 | 39篇 |
2017年 | 37篇 |
2016年 | 36篇 |
2015年 | 44篇 |
2014年 | 43篇 |
2013年 | 83篇 |
2012年 | 73篇 |
2011年 | 105篇 |
2010年 | 73篇 |
2009年 | 54篇 |
2008年 | 61篇 |
2007年 | 59篇 |
2006年 | 56篇 |
2005年 | 40篇 |
2004年 | 34篇 |
2003年 | 34篇 |
2002年 | 31篇 |
2001年 | 18篇 |
2000年 | 10篇 |
1999年 | 24篇 |
1998年 | 22篇 |
1997年 | 15篇 |
1996年 | 15篇 |
1995年 | 8篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 8篇 |
1988年 | 2篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 9篇 |
1962年 | 1篇 |
1961年 | 2篇 |
排序方式: 共有1307条查询结果,搜索用时 15 毫秒
121.
Claire M. Côte Chris J. Moran Christopher J. Hedemann 《Mine Water and the Environment》2007,26(4):229-236
Unprecedented expansion of coal mining in Australia is occurring within the context of a severe ongoing drought. This has
induced more companies to adopt improved water management strategies, such as water reuse. A direct consequence of this is
an increase in the salt concentration of the water, which affects in turn the efficiency of the coal preparation processes,
the quality of the coal product, and the level of required equipment maintenance. There are three strategies that can be adopted
with respect to salt management: accept the elevated salt concentrations and increase spending on equipment maintenance; remove
the salt by desalination; and dilute the salt by importing more water. A tool is required to predict the salt concentrations
arising from water reuse and to simulate the impact of potential management strategies. This paper presents a systems approach
to the modelling of coupled mine site water and salt balances to assist with understanding the implications of implementing
desalination or dilution and with assessing the costs and benefits of each option. 相似文献
122.
Two processes have been hypothesized to underlie improvement in perception: attunement and calibration. These processes were examined in a dynamic touch paradigm in which participants were asked to report the lengths of unseen, wielded rods differing in length, diameter, and material. Two experiments addressed whether feedback informs about the need for reattunement and recalibration. Feedback indicating actual length induced both recalibration and reattunement. Recalibration did not occur when feedback indicated only whether 2 rods were of the same length or of different lengths. Such feedback, however, did induce reattunement. These results suggest that attunement and calibration are dissociable processes and that feedback informs which is needed. The observed change in variable use has implications also for research on what mechanical variables underlie length perception by dynamic touch. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
123.
David Helbert Philippe Carré Eric Andres 《IEEE transactions on image processing》2006,15(12):3701-3714
In this paper, we propose an implementation of the 3-D Ridgelet transform: the 3-D discrete analytical Ridgelet transform (3-D DART). This transform uses the Fourier strategy for the computation of the associated 3-D discrete Radon transform. The innovative step is the definition of a discrete 3-D transform with the discrete analytical geometry theory by the construction of 3-D discrete analytical lines in the Fourier domain. We propose two types of 3-D discrete lines: 3-D discrete radial lines going through the origin defined from their orthogonal projections and 3-D planes covered with 2-D discrete line segments. These discrete analytical lines have a parameter called arithmetical thickness, allowing us to define a 3-D DART adapted to a specific application. Indeed, the 3-D DART representation is not orthogonal, It is associated with a flexible redundancy factor. The 3-D DART has a very simple forward/inverse algorithm that provides an exact reconstruction without any iterative method. In order to illustrate the potentiality of this new discrete transform, we apply the 3-D DART and its extension to the Local-DART (with smooth windowing) to the denoising of 3-D image and color video. These experimental results show that the simple thresholding of the 3-D DART coefficients is efficient. 相似文献
124.
Monsell Stephen; Patterson Karalyn E.; Graham Andrew; Hughes Claire H.; Milroy Robert 《Canadian Metallurgical Quarterly》1992,18(3):452
Two experiments on oral reading of single words compared naming performance in pure blocks of nonwords or exception words with performance in blocks of randomly mixed nonwords and exception words. Ss named exception words faster and made fewer regularization errors when they were not also prepared for nonwords. These data suggest Ss inhibit or ignore the computation of assembled phonology when only exception words are expected. Ss named nonwords faster, but no more accurately, when low-frequency exception words were not also anticipated. Thus, Ss' readiness to execute assembled phonology appears to be adjusted in relation to the likely time course of retrieval of learned pronunciations, when the latter must be attended to. This evidence for strategic dissociation between sublexical and lexical translation is discussed in relation to current models. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
125.
126.
Jessica Tabart Claire Kevers Arnaud Sipel Joël Pincemail Jean-Olivier Defraigne Jacques Dommes 《Food chemistry》2007,105(3):1268-1275
Health benefits of a diet rich in fruits and vegetables are attributed in part to their contents of phenolics and other antioxidant compounds. In this research, the extraction of phenolics and antioxidant compounds from black currant was optimised for different plant organs. The extraction solvent affected yield: aqueous acetone was better than methanol and acetate or glycine buffer. In aqueous buffer, maximum yields of total phenolics and antioxidant activities were obtained at pH 3. Extraction from lyophilised materials yielded extracts with higher phenolic contents and antioxidant activities. 相似文献
127.
Vaughn Brian E.; Kopp Claire B.; Krakow Joanne B.; Johnson Kim; Schwartz Steven S. 《Canadian Metallurgical Quarterly》1986,22(6):752
Conducted 2 studies to examine the behavior of young children in tasks demanding self-control. In Study 1, 27 2-yr-olds were observed in 1 task. Behavior during the task was described using a 10-category coding system, and proportion scores derived from the 10-category coding system were correlated with total time in the task. Results show that 5 of the 10 correlations were significant. Behaviors bringing the goals into attention were negatively correlated with total delay time, whereas behaviors taking the goal out of attention tended to be positively associated with delay. In Study 2, 82 children (aged 24–36 mo) were observed in 3 delay tasks. The behavioral strategy studied was directing attention away from the goal object during delay periods. Significant effects were found for age and task type. When the sample was divided into shorter vs longer waiters, it was found that the longer waiters looked away from the goal for a larger proportion of the time. It is suggested that young children use implicit strategies for controlling their behavior in the face of a social demand. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
128.
Preschool children's ability to distinguish between pretense and reality was examined in 2 studies that adopted a modified version of the design used by P. L. Harris, E. Brown, M. Marriott, S. Whittall, and S. Harmer (1991) in which a pretend creature is assumed to hide inside a box. In Study 1, 19 4-year-olds participated in test conditions that closely followed Harris et al.'s procedures. In Study 2, 75 3- and 4-year-olds were randomly assigned to 1 of 4 emotionally colored pretense play scenarios that included 4 test conditions: an imaginary creature, invented by the adult or the child, whose affective value was either positive or negative. The results of both studies do not support Harris et al.'s interpretation of their data in terms of a breakdown of the distinction between pretense and reality. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
129.
Reaction time, movement time, and initial direction of reaching movements toward a target in left or right hemispace were measured. In Experiment 1, the target of movement and hand had to be selected; movements toward the imperative stimulus were initiated faster than movements toward the alternate target, and ipsilateral reaches were initiated faster than contralateral reaches. In Experiment 2, the difference between ipsilateral and contralateral reaches disappeared when no selection of the hand had to occur. In Experiment 3, no target had to be selected, and only a stimulus-hand compatibility effect appeared. The results reveal different compatibility effects (stimulus-target, stimulus-hand, target-hand), implying that participants exploit different correspondences, depending on the degrees of freedom of the action. The notion of compatibility effects relating to movement targets offers a new perspective on the negative Simon effect and it questions the general concept of response codes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
130.
Xiaohan?Wu Mario?El Kazzi Claire?VillevieilleEmail author 《Journal of Electroceramics》2017,38(2-4):207-214
All-solid-state lithium-ion batteries represent a promising battery technology thanks to the replacement of the volatile and flammable state-of-the-art liquid electrolyte by a solid electrolyte. Despite the recent progress in the synthesis of sulfide based solid electrolyte with high ionic conductivity, little is known about the interface reactivity of the solid electrolyte with electrode materials. In this study, we synthesized and characterized an amorphous solid electrolyte with the nominal composition (Li2S)3(P2S5). We assessed the feasibility of using this electrolyte at the laboratory scale, and we discuss the potential challenges that govern its electrochemical performance. Galvanostatic cycling and rate performance measurements were conducted using lithium titanium oxide (Li4Ti5O12) as the negative electrode material. The electrochemical measurements were performed using two different counter electrodes, namely Li metal and an InLix alloy. The alloy counter electrode suppressed the formation of lithium dendrites, resulting in increased cycling stability and cell safety. Post mortem X-ray photoemission spectroscopy measurements reveal the reactivity of the solid electrolyte Li3PS4 with the Li4Ti5O12, lithium metal, and InLix alloy. 相似文献