全文获取类型
收费全文 | 231篇 |
免费 | 13篇 |
专业分类
化学工业 | 28篇 |
金属工艺 | 4篇 |
机械仪表 | 13篇 |
建筑科学 | 4篇 |
矿业工程 | 1篇 |
能源动力 | 5篇 |
轻工业 | 50篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 30篇 |
一般工业技术 | 21篇 |
冶金工业 | 29篇 |
自动化技术 | 55篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2017年 | 12篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 21篇 |
2012年 | 18篇 |
2011年 | 10篇 |
2010年 | 10篇 |
2009年 | 13篇 |
2008年 | 7篇 |
2007年 | 13篇 |
2006年 | 8篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 2篇 |
1999年 | 4篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有244条查询结果,搜索用时 31 毫秒
71.
Head-mounted display versus desktop for 3D navigation in virtual reality: a user study 总被引:1,自引:1,他引:0
Beatriz Sousa Santos Paulo Dias Angela Pimentel Jan-Willem Baggerman Carlos Ferreira Samuel Silva Joaquim Madeira 《Multimedia Tools and Applications》2009,41(1):161-181
Virtual Reality (VR) has been constantly evolving since its early days, and is now a fundamental technology in different application
areas. User evaluation is a crucial step in the design and development of VR systems that do respond to users’ needs, as well
as for identifying applications that indeed gain from the use of such technology. Yet, there is not much work reported concerning
usability evaluation and validation of VR systems, when compared with the traditional desktop setup. The paper presents a
user study performed, as a first step, for the evaluation of a low-cost VR system using a Head-Mounted Display (HMD). That
system was compared to a traditional desktop setup through an experiment that assessed user performance, when carrying out
navigation tasks in a game scenario for a short period. The results show that, although users were generally satisfied with
the VR system, and found the HMD interaction intuitive and natural, most performed better with the desktop setup.
相似文献
Beatriz Sousa SantosEmail: |
72.
73.
74.
Maíra Patricio Silveira Helen Costa Silva Ida Chapaval Pimentel Carolina Gracia Poitevin Andressa Katiski da Costa Stuart Danielle Carpiné Luiz Mario de Matos Jorge Regina Maria Matos Jorge 《应用聚合物科学杂志》2020,137(21):48726
In the present study, a cassava starch-glycerol film with reinforcement of Pinus sp. nanofibers (NFC) incorporated with tea tree (Melaleuca alternifolia) essential oil (TTO) were prepared by casting technique. The physical (barrier, mechanical, and optical), structural, and antimicrobial properties of the films were evaluated and compared with the control films. Films with 0.08% TTO exhibited a significant increase in the tensile strength (TS) while films with 1.5% TTO showed a decrease in TS, suggesting a crosslinking effect. The addition of 1.5% TTO reduced the water vapor permeability values in 43% comparing to the control films. Analysis obtained by Fourier transform infrared spectroscopy showed bands related to the interaction between TTO and matrix for films with 1.5% TTO and 0.3% NFC. This film was effective against Staphylococcus aureus and Candida albicans which could be applied for several packaging purposes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48726. 相似文献
75.
C. S. Ranadheera C. A. Evans S. K. Baines Celso F. Balthazar Adriano G. Cruz Erick A. Esmerino Mnica Q. Freitas Tatiana C. Pimentel A. E. Wittwer N. Naumovski Juliana S. Graa Anderson S. Sant'Ana S. Ajlouni T. Vasiljevic 《Comprehensive Reviews in Food Science and Food Safety》2019,18(4):867-882
Dairy foods, particularly those of bovine origin, are the predominant vehicles for delivery of probiotic bacteria. Caprine (goat) milk also possesses potential for successful delivery of probiotics, and despite its less appealing flavor in some products, the use of goat milk as a probiotic carrier has rapidly increased over the last decade. This review reports on the diversity, applicability, and potential of using probiotics to enhance the sensory properties of goat milk and goat milk‐based products. A brief conceptual introduction to probiotic microorganisms is followed by an account of the unique physicochemical, nutritive, and beneficial aspects of goat milk, emphasizing its advantages as a probiotic carrier. The sensory properties of probiotic‐enriched goat milk products are also discussed. The maintenance of probiotic viability and desirable physicochemical characteristics in goat milk products over shelf life is possible. However, the unpleasant sensory features of some goat milk products remain a major disadvantage that hinder its wider utilization. Nevertheless, certain measures such as fortification with selected probiotic strains, inclusion of fruit pulps and popular flavor compounds, and production of commonly consumed tailor‐made goat milk‐based products have potential to overcome this limitation. In particular, certain probiotic bacteria release volatile compounds as a result of their metabolism, which are known to play a major role in the aroma profile and sensory aspects of the final products. 相似文献
76.
Sílvia Pimentel Marconi Germer Marcelo Antônio Morgano Marta Gomes da Silva Neliane Ferraz de Arruda Silveira Elaine de Cássia Guerreiro Souza 《Drying Technology》2016,34(8):997-1008
The aim of this study was to assess the effect of reconditioning and reuse (RR) of sucrose syrup in quality properties and retention of nutrients in guava during osmotic dehydration (OD). Two trials of 15 OD cycles were conducted with RR of osmotic solution. The parameters of water loss (WL) and solid incorporation (SI), as well as microbial load and physical–chemical properties of syrup and fruit were evaluated. The results showed that the RR did not modify the parameters WL and SI, and the microbial load remained low. The RR did not influence the color of osmodehydrated fruit, as well as the nutrient retentions, but probably it influenced the citric acid and reduced sugar retentions. At the end, the syrup was enriched of vitamin C, polyphenols, potassium, with traces of lycopene, β-carotene, and other minerals (Fe, Mg, Mn, and Zn) and could be used to formulate new products. 相似文献
77.
Phosphine resistance was assessed in adults of 22 Brazilian populations of Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). The concentration-mortality bioassays for the detection of phosphine resistance followed the FAO standard method. Twenty populations of S. zeamais were resistant to phosphine and the resistance ratios at the LC50 ranged from 1.1- to 86.6-fold. This is the first report of phosphine resistance in populations of S. zeamais in Brazil, where previous surveys did not detect resistance in this species. There was significant variation in respiration rate (CO2 production) among the populations (P < 0.05). Respiration rate was significantly inversely correlated with phosphine resistance for this species (P < 0.05). The populations with lower respiration rates showed higher levels of phosphine resistance, suggesting that the lower respiration rate is associated with the physiological basis of phosphine resistance due to reduced fumigant uptake. 相似文献
78.
79.
A significant number of accidents has occurred with demountable grandstands in the past as well as recently. The performance of such structures is the subject of this paper. First, structural details and some structural systems of actual grandstands are presented and discussed. Next, specifics of the design, erection, and inspection process are detailed. Finally, a survey of cases of collapse of demountable grandstands is presented and discussed. Ninety three cases of collapse were found between the years 1889 and 2008, in which more than 85 people died and 6,350 were injured. From these, 35 cases in which information about the causes of collapse were available were selected. An analysis of the causes showed that unexpected or excessive loads were the major contributing cause, followed by problems with the supports, connections, and bracing. Possible measures that could be adopted aimed at minimizing the risk of accidents with these structures are discussed. 相似文献
80.
E. Fortunato L. Raniero L. Silva A. Gonçalves A. Pimentel P. Barquinha H. Águas L. Pereira G. Gonçalves I. Ferreira E. Elangovan R. Martins 《Solar Energy Materials & Solar Cells》2008,92(12):1605-1610
Transparent and highly conducting gallium zinc oxide (GZO) films were successfully deposited by RF sputtering at room temperature. A lowest resistivity of ∼2.8×10−4 Ω cm was achieved for a film thickness of 1100 nm (sheet resistance ∼2.5 Ω/□), with a Hall mobility of 18 cm2/V s and a carrier concentration of 1.3×1021 cm−3. The films are polycrystalline with a hexagonal structure having a strong crystallographic c-axis orientation. A linear dependence between the mobility and the crystallite size was obtained. The films are highly transparent (between 80% and 90% including the glass substrate) in the visible spectra with a refractive index of about 2, very similar to the value reported for the bulk material. These films were applied to single glass/TCO/pin hydrogenated amorphous silicon solar cells as front layer contact, leading to solar cells with efficiencies of about 9.52%. With the optimized deposition conditions, GZO films were also deposited on polymer (PEN) substrates and the obtained results are discussed. 相似文献