全文获取类型
收费全文 | 966篇 |
免费 | 74篇 |
专业分类
电工技术 | 4篇 |
综合类 | 1篇 |
化学工业 | 474篇 |
金属工艺 | 3篇 |
机械仪表 | 26篇 |
建筑科学 | 48篇 |
能源动力 | 14篇 |
轻工业 | 185篇 |
水利工程 | 4篇 |
石油天然气 | 1篇 |
无线电 | 18篇 |
一般工业技术 | 101篇 |
冶金工业 | 102篇 |
原子能技术 | 3篇 |
自动化技术 | 56篇 |
出版年
2024年 | 3篇 |
2023年 | 11篇 |
2022年 | 110篇 |
2021年 | 96篇 |
2020年 | 42篇 |
2019年 | 31篇 |
2018年 | 31篇 |
2017年 | 36篇 |
2016年 | 34篇 |
2015年 | 30篇 |
2014年 | 43篇 |
2013年 | 65篇 |
2012年 | 57篇 |
2011年 | 69篇 |
2010年 | 42篇 |
2009年 | 28篇 |
2008年 | 38篇 |
2007年 | 36篇 |
2006年 | 30篇 |
2005年 | 24篇 |
2004年 | 19篇 |
2003年 | 18篇 |
2002年 | 17篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1999年 | 3篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 13篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有1040条查询结果,搜索用时 15 毫秒
91.
Perri Roberta; Serra Laura; Carlesimo Giovanni Augusto; Caltagirone Carlo 《Canadian Metallurgical Quarterly》2007,21(5):549
Episodic long-term, short-term, and implicit memory were investigated in 79 elderly subjects who fulfilled criteria for the amnestic form of mild cognitive impairment (a-MCI; i.e., by having an idiopathic amnestic disorder with absence of impairment in cognitive areas other than memory and without confounding medical or psychiatric conditions) and who developed Alzheimer's disease (AD) after 2 years as well as in 111 subjects affected by a-MCI who did not develop dementia. Results document a memory profile in a-MCI subjects characterized by preserved short-term and implicit memory and extensive impairment of episodic long-term memory. In virtually all episodic memory indexes examined (learning, forgetting, recognition abilities), a-MCI subjects who converted to AD were more severely impaired than were subjects who did not become demented. This memory profile, which closely resembles that exhibited by amnestic patients with bilateral mesial-temporal lobe lesions, confirms a precocious phase in preclinical AD characterized by selective involvement of mesial-temporal areas and worsening of the memory impairment as atrophic changes progress in hippocampal structures. In this context of pervasive episodic memory impairment, tests assessing the free recall of verbal material following a delay interval demonstrated the greater sensitivity to memory deficits of a-MCI subjects who developed AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
92.
93.
Recovery of platinum, tin and indium from spent catalysts in chloride medium using strong basic anion exchange resins 总被引:1,自引:0,他引:1
This work describes a route for platinum recovery from spent commercial Pt and PtSnIn/Al2O3 catalysts using strong basic mesoporous and macroporous anion exchange resins (Cl− form). The catalysts were leached with aqua regia (75 °C, 20-25 min). Platinum adsorption was influenced by the presence of other metals which form chlorocomplexes (tin, indium) and also base metals (aluminum). However, it was possible to overcome this fact by a sequential desorption procedure. Aluminum was selectively removed from the resins by elution with 3 mol L−1 HCl. Platinum was desorbed passing 1 mol L−1 Na2S2O3 (pH 9). Tin was removed by elution with 0.1 mol L−1 ascorbic acid. Indium was removed using 0.1 mol L−1 EDTA as eluent. Desorption efficiency exceeded 99% for all metals. Metals were recovered in high yields (>98 wt%). 相似文献
94.
Previous research, by R. M. Golinkoff and R. R. Rosinski (1976), used a picture-word interference task to show that skilled and less skilled comprehenders in the 3rd and 5th grades could retrieve the meaning of primer-level words equally well. With a similar task and comparable groups of children ( N = 64), the present study assessed the relationship between word difficulty and semantic access by using both the easy words and a new set of more difficult words. Retrieval of the meaning of these difficult words was least apparent for the less skilled 3rd graders, the group that had the most difficulty decoding these words. Results indicate that decoding ease and extraction of word meanings are related and also suggest that decoding ability must be considered a factor in reading comprehension. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
95.
96.
Nadia Segura Roberta Claro da Silva Fabiana A. Schäfer de M. Soares Luiz Antonio Gioielli Iván Jachmanián 《Journal of the American Oil Chemists' Society》2011,88(12):1945-1954
Although beef tallow (BT) has been considered a hard low-trans fat convenient to be used in several bakery applications, it has some undesirable characteristics like fatty acid composition, crystallization behavior, graininess formation and poor plastic range. This work studied the modification of BT by blending at different percentages with high oleic sunflower oil (HOSFO) followed by the enzyme-catalyzed interesterification of the blends. The reduction in the solid fat content achieved by the simple blending was enhanced by the interesterification process, as a result of the increase in the concentration of the diunsaturated monosaturated type triacylglycerols. Interesterification strongly impacted too on the crystallization behavior of the blends, since products showed more homogeneous and regular crystals than the starting mixture. Results show that lipase catalyzed interesterification of BT with HOSFO offers a useful tool for the design of fats with adjustable physicochemical properties, improved with respect to that of the starting fats. 相似文献
97.
Giovanni Pioggia Roberta Igliozzi Marcello Ferro Arti Ahluwalia Filippo Muratori Danilo De Rossi 《IEEE transactions on neural systems and rehabilitation engineering》2005,13(4):507-515
It is well documented that the processing of social and emotional information is impaired in people with autism. Recent studies have shown that individuals, particularly those with high functioning autism, can learn to cope with common social situations if they are made to enact possible scenarios they may encounter in real life during therapy. The main aim of this work is to describe an interactive life-like facial display (FACE) and a supporting therapeutic protocol that will enable us to verify if the system can help children with autism to learn, identify, interpret, and use emotional information and extend these skills in a socially appropriate, flexible, and adaptive context. The therapeutic setup consists of a specially equipped room in which the subject, under the supervision of a therapist, can interact with FACE. The android display and associated control system has automatic facial tracking, expression recognition, and eye tracking. The treatment scheme is based on a series of therapist-guided sessions in which a patient communicates with FACE through an interactive console. Preliminary data regarding the exposure to FACE of two children are reported. 相似文献
98.
Object
The objective of this study is to propose a modified VARiable PROjection (VARPRO) algorithm specifically tailored for fitting the intravoxel incoherent motion (IVIM) model to diffusion-weighted magnetic resonance imaging (DW-MRI) data from locally advanced rectal cancer (LARC).Materials and methods
The proposed algorithm is compared with classical non-linear least squares (NLLS) analysis using the Levenberg-Marquardt (LM) algorithm and with two recently proposed algorithms for ‘segmented’ analysis. These latter two comprise two consecutive steps: first, a subset of parameters is estimated using a portion of data; second, the remaining parameters are estimated using the whole data and the previous estimates. The comparison between the algorithms was based on the \(R^2\) goodness-of-fit measure: performance analysis was carried out on real data obtained by DW-MRI on 40 LARC patients.Results
The performance of the proposed algorithm was higher than that of LM in 64 % of cases; ‘segmented’ methods were poorer than our algorithm in 100 % of cases.Conclusion
The proposed modified VARPRO algorithm can lead to better fit of the IVIM model to LARC DW-MRI data compared to other techniques.99.
Roberta Di Benedetto Renzo Alfini Martina Carducci Maria Grazia Aruta Luisa Lanzilao Alessandra Acquaviva Elena Palmieri Carlo Giannelli Francesca Necchi Allan Saul Francesca Micoli 《International journal of molecular sciences》2021,22(19)
Outer Membrane Vesicles (OMV) constitute a promising platform for the development of efficient vaccines. OMV can be decorated with heterologous antigens (proteins or polysaccharides), becoming attractive novel carriers for the development of multicomponent vaccines. Chemical conjugation represents a tool for linking antigens, also from phylogenetically distant pathogens, to OMV. Here we develop two simple and widely applicable conjugation chemistries targeting proteins or lipopolysaccharides on the surface of Generalized Modules for Membrane Antigens (GMMA), OMV spontaneously released from Gram-negative bacteria mutated to increase vesicle yield and reduce potential reactogenicity. A Design of Experiment approach was used to identify optimal conditions for GMMA activation before conjugation, resulting in consistent processes and ensuring conjugation efficiency. Conjugates produced by both chemistries induced strong humoral response against the heterologous antigen and GMMA. Additionally, the use of the two orthogonal chemistries allowed to control the linkage of two different antigens on the same GMMA particle. This work supports the further advancement of this novel platform with great potential for the design of effective vaccines. 相似文献
100.
Philbeck John W.; Klatzky Roberta L.; Behrmann Marlene; Loomis Jack M.; Goodridge Jeremy 《Canadian Metallurgical Quarterly》2001,27(1):141
In some navigation tasks, participants are more accurate if they view the environment beforehand. To characterize the benefits associated with visual previews, 32 blindfolded participants were guided along simple paths and asked to walk unassisted to a specified destination (e.g., the origin). Paths were completed without vision, with or without a visual preview of the environment. Previews did not necessarily improve nonvisual navigation. When previewed landmarks stood near the origin or at off-path locations, they provided little benefit; by contrast, when they specified intermediate destinations (thereby increasing the degree of active control), performance was greatly enhanced. The results suggest that the benefit of a visual preview stems from the information it supplies for actively controlled locomotion. Accuracy in reaching the final destination, however, is strongly contingent upon the destination's location during the preview. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献