全文获取类型
收费全文 | 106篇 |
免费 | 5篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 2篇 |
综合类 | 2篇 |
化学工业 | 17篇 |
金属工艺 | 3篇 |
机械仪表 | 3篇 |
建筑科学 | 4篇 |
能源动力 | 1篇 |
轻工业 | 17篇 |
石油天然气 | 7篇 |
无线电 | 22篇 |
一般工业技术 | 16篇 |
冶金工业 | 4篇 |
原子能技术 | 4篇 |
自动化技术 | 11篇 |
出版年
2023年 | 2篇 |
2022年 | 9篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 1篇 |
2009年 | 6篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 7篇 |
2003年 | 5篇 |
2002年 | 1篇 |
2001年 | 4篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 1篇 |
排序方式: 共有113条查询结果,搜索用时 31 毫秒
71.
O.?O.?AlakaEmail author J.?O.?Aina K.?O.?Falade 《European Food Research and Technology》2003,218(1):79-82
Mango juices were extracted from Ogbomoso variety using the method of Brekke et al. (1972). Mango juices were packaged in polyethylene films, polyethylene tetraphthalate (PET or plastic) bottles and transparent glass bottles and stored at 6 °C, 26 °C and 34 °C. Percentage ascorbic acid loss, browning index, titratable acidity, pH and soluble solids were evaluated at 2-week intervals for 8 weeks. Percentage ascorbic acid loss, non-enzymatic browning and titratable acidity increased with storage time in all packaging materials. However, pH decreased with storage time and soluble solids remained constant. Higher percentage ascorbic acid loss, browning index and titratable acidity occurred in juices packaged in polyethylene film, than in PET and glass bottles. Percentage ascorbic acid, browning index and pH increased with increased storage temperature. However, titratable acidity decreased with increased storage temperature and soluble solids remained constant throughout the period of storage. 相似文献
72.
基于C8051F020无创血压测量系统的设计 总被引:1,自引:0,他引:1
血压和脉率是人体的重要生理参数,准确地测量人体血压和脉率对人体的健康起着非常重要的作用;文中介绍了以C8051F020为核心的无创血压测量系统,从硬件和软件两个方面详细说明了设计方法;血压信号通过前端放大电路和滤波电路后,经过单片机采集后运算得到血压值和脉率值,最后系统通过LCD动态实时显示测量的结果,同时给出了在遇到异常情况时处理的方法,保证了无创血压测量的安全性;经过实验表明,使用方便灵活,具有较高的临床应用价值。 相似文献
73.
Julián Lozano-Castellón Anallely López-Yerena Inés Domínguez-López Aina Siscart-Serra Nathalia Fraga Samantha Sámano Carmen López-Sabater Rosa M Lamuela-Raventós Anna Vallverdú-Queralt Maria Pérez 《Comprehensive Reviews in Food Science and Food Safety》2022,21(3):2639-2664
The growing demand for extra virgin olive oil (EVOO), appreciated for its unique organoleptic properties and health benefits, has led to various fraudulent practices to maximize profits, including dilution with lower value edible oils. The adulterated oils would be of poor nutritional quality, more readily oxidized, and may contain unhealthy substances formed during processing. Nevertheless, the range of available techniques to detect fraud in EVOO production has been growing. Reliable markers of EVOO adulteration include fatty acids and minor components such as sterols, tocopherols, triterpene alcohols, phenolic compounds, phospholipids, volatile compounds, and pigments. Additionally, increasing consumer interest in high-quality EVOO has led to the development of robust scientific methods for its traceability. This review focuses on (i) the usefulness of certain compounds as markers of EVOO adulteration; (ii) the potential health risks of consuming adulterated EVOO; and (iii) reliable methods for the geographical traceability of olive oil. In conclusion, fraudulent production practices need to be detected to preserve the beneficial health effects of EVOO and to avoid the potential risks associated with ingesting substandard oil. In this work, as EVOO certification and regulatory framework limitations have already been extensively reviewed, we focus our attention on biomarkers that guarantee both the authenticity and traceability of oil, and consequently its health properties. When it is unavailable to obtain a high-resolution mass spectrometry full fingerprint, stigmastadienes and the sterolic profile are proposed as reliable markers. 相似文献
74.
75.
电信运营商做好节能减排工作的建议 总被引:1,自引:0,他引:1
从国家战略和整体经济出发,分析了电信运营商进行节能减排的必要性和可能性,阐述了电信运营商作为超大规模的经济体节能减排对于国家和对于企业自己本身的重大意义。最后,提出了节能减排的原则思路和工作建议。 相似文献
76.
JJ Mira Solves JA Buil Aina J Rodríguez-Marín J Aranaz Andrés 《Canadian Metallurgical Quarterly》1997,11(4):176-189
For the functional psychoses of late life, epidemiological information comes from two sources: studies of persons who have reached psychiatric services; and surveys of elderly persons sampled from the general population. A conspectus of published data from both sources leads to the following conclusions: States phenomenologically similar to those found in clinics do occur in the community in non-trivial numbers. There is no notable divergence in the information obtained from clinical series and from population-based surveys. These states are more common in women, they become more common with increasing age and are sometimes associated with decline in cognitive performance or with degenerative changes in the brain revealed by neuroimaging. Genetic factors appear to be less important than in early-onset psychoses but remain ill-defined, and the roles of social isolation and disorders of personality have not yet been sufficiently elucidated. Both clinical and community-based studies have found an association with sensory impairment. The community-based data suggest that paranoid symptoms may be detectable at subclinical level, and an association between them and cognitive impairment is demonstrable in individuals who are not diagnosable cases either of psychosis or of dementia. Differences exist between late-onset paranoid psychoses and affective psychoses in symptomatology and response to treatment. These observations confirm the importance of the late-onset psychoses for research directed towards uncovering the origins of psychotic symptoms in any age group. 相似文献
77.
Low efficiency of available screening procedures constrains breeding and selection of yams (Dioscorea spp.) towards high textural quality of food products made from their tubers. This study was undertaken to determine the potential usefulness of pasting characteristics of fresh yams as rapid indicators of food textural quality in ‘pounded yam’, a staple food for millions of yam consumers, especially in West and Central Africa. Significant associations (P < 0.05) were found, through canonical correlation analysis, between pasting characteristics of fresh yams from six varieties, each, of Dioscorea rotundata and Dioscorea alata and the textural quality of pounded yam samples prepared from them. Good textural quality of pounded yam was associated with high peak viscosity, breakdown, final viscosity, holding strength and setback viscosity but with low pasting temperature in the fresh yam. 相似文献
78.
Adebisola J. Aina Kolawole O. Falade John O. Akingbala & Pathelene Titus 《International Journal of Food Science & Technology》2009,44(9):1696-1704
The physical, chemical and physicochemical properties of twenty-one Caribbean sweet potato cultivars were investigated. Hunter L a b colour parameters were measured, chroma, colour intensity and hue angle were calculated. Proximate composition, vitamin C, amylose, reducing and non-reducing sugars contents were determined using standard methods. Pasting properties were determined using Rapid Visco Analyser. Tuber size (length, r = 0.72, n = 21, P < 0.0015; width, r = 0.85, n = 21, P < 0.0002) was highly correlated with weight of the tubers. External colours of the tubers ( L = 28.7–63.1, a = +5.9 to +18.0, b = +3 to +19.3) were lower than the flesh colours ( L = 60.8–84.0, a = −2.4 to +27.8, b = +9.9 to +28.5). Proximate composition is typical of sweet potato cultivars but significant differences exist among cultivars. Total sugar, amylose and amylopectin contents ranged from 1.8 to 4.7%, 15.3–31.2% and 68.8–84.7%, respectively. Cooking profiles of the sweet potato flours showed similar trend. Pasting temperature, peak time, swelling power and solubility ranged from 78.3 to 93.0 °C, 3.3–4.8 min, 5.6–23.5 and 11.7–45.7%, respectively. 相似文献
79.
The fabrication of the first AlInAs/InP HEMT is reported. This device has extrinsic transconductance of 40 mS/mm, gate-drain and drain-source breakdown voltages of 20 V and saturation drain current densities of 0.1 A/mm of gate width. These preliminary results show the potential of the AlInAs/InP heterojunctions for a wide variety of application including microwave power HEMTs.<> 相似文献
80.
Martin E.A. Aina O.A. Iliadis A.A. Mattingly M.R. Hempfling E. 《Electron Devices, IEEE Transactions on》1990,37(8):1916-1917
The fabrication and microwave performance of InP/InGaAs heterojunction insulated-gate FETs (HIGFETs) using plasma-enhanced chemical vapor deposition (PECVD)-deposited SiO2 as the gate insulator are discussed. Extrinsic transconductances as high as 240 mS/mm were obtained. Although these devices had a drain current drift of 20% under DC bias, when operated at 5 GHz they exhibited negligible drain current drift. The observation of high transconductance and stable microwave performance makes these HIGFETs ideal candidates for microwave power applications 相似文献