全文获取类型
收费全文 | 228篇 |
免费 | 30篇 |
专业分类
化学工业 | 67篇 |
金属工艺 | 3篇 |
机械仪表 | 3篇 |
建筑科学 | 10篇 |
矿业工程 | 1篇 |
能源动力 | 5篇 |
轻工业 | 38篇 |
无线电 | 27篇 |
一般工业技术 | 51篇 |
冶金工业 | 10篇 |
原子能技术 | 2篇 |
自动化技术 | 41篇 |
出版年
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 25篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 10篇 |
2017年 | 13篇 |
2016年 | 10篇 |
2015年 | 11篇 |
2014年 | 19篇 |
2013年 | 19篇 |
2012年 | 11篇 |
2011年 | 18篇 |
2010年 | 16篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 14篇 |
2006年 | 10篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
排序方式: 共有258条查询结果,搜索用时 140 毫秒
11.
Enhancement of phenolic compounds content and antioxidant activity of strawberry (Fragaria × ananassa) juice by block freeze concentration technology 下载免费PDF全文
Wantiê T. Adorno Katia Rezzadori Giordana D. Arend Vitor C. Chaves Flávio H. Reginatto Marco Di Luccio José C.C. Petrus 《International Journal of Food Science & Technology》2017,52(3):781-787
The aim of this study was to evaluate the effects of freeze concentration of strawberry juice on content of total phenolic, anthocyanins content and antioxidant activity of the concentrated fluid and the ice obtained. An increase in the values of phenolic content was observed in the concentrate fraction for all the freeze concentration stages (five stages). The process efficiency presented a reduction when compared with the first stage, and however, the average efficiency remained around 65% in all the stages. The concentration of pelargonidin‐3‐O‐glycoside present in samples was increased in all stages. Furthermore, the antioxidant activity of the concentrated fluid of each stage, measured by DPPH and ABTS methods, was significantly higher in comparison with the juice feed. Also, antioxidant activity can be correlated with the content of pelargonidin‐3‐O‐glycoside presented in the strawberry juice. Freeze concentration can be considered a good alternative for improving the antioxidant activity of strawberry juice. 相似文献
12.
Application and bioactive properties of CaTI,a trypsin inhibitor from Capsicum annuum seeds: membrane permeabilization,oxidative stress and intracellular target in phytopathogenic fungi cells 下载免费PDF全文
13.
Lucimara C Bandeira Paulo S Calefi Katia J Ciuffi Emerson H de Faria Eduardo J Nassar Miguel A Vicente Raquel Trujillano 《Polymer International》2012,61(7):1170-1176
Polymer/clay composites have several uses in fields such as engineering, agriculture, ceramics, surface coatings, absorbent materials, pharmaceuticals or catalysis. Polysaccharides, such as alginate and its acid derivatives, are biocompatible and biodegradable polymers, effective in the production of adsorbent systems, for encapsulation and controlled release of active ingredients such as drugs and fertilizers. In this work, alginate polysaccharide and alginic acid were used to form composites with laponite, both with the original clay or with clay previously functionalized with 3‐aminopropyltriethoxysilane. The properties of the composites prepared from laponite or functionalized laponite and alginic acid or alginate were compared. The interaction of laponite with alginic acid leads to composites with strong disorder in the clay structure. In all cases, composites with high contents of polysaccharides, with good thermal and mechanical properties, are obtained. Laponite‐derived composites showed high adsorption capability for Cr(III) and methylene blue from aqueous medium. Copyright © 2012 Society of Chemical Industry 相似文献
14.
In recent years, the within-host viral dynamics of dengue infections have been increasingly characterized, and the relationship between aspects of these dynamics and the manifestation of severe disease has been increasingly probed. Despite this progress, there are few mathematical models of within-host dengue dynamics, and the ones that exist focus primarily on the general role of immune cells in the clearance of infected cells, while neglecting other components of the immune response in limiting viraemia. Here, by considering a suite of mathematical within-host dengue models of increasing complexity, we aim to isolate the critical components of the innate and the adaptive immune response that suffice in the reproduction of several well-characterized features of primary and secondary dengue infections. By building up from a simple target cell limited model, we show that only the innate immune response is needed to recover the characteristic features of a primary symptomatic dengue infection, while a higher rate of viral infectivity (indicative of antibody-dependent enhancement) and infected cell clearance by T cells are further needed to recover the characteristic features of a secondary dengue infection. We show that these minimal models can reproduce the increased risk of disease associated with secondary heterologous infections that arises as a result of a cytokine storm, and, further, that they are consistent with virological indicators that predict the onset of severe disease, such as the magnitude of peak viraemia, time to peak viral load, and viral clearance rate. Finally, we show that the effectiveness of these virological indicators to predict the onset of severe disease depends on the contribution of T cells in fuelling the cytokine storm. 相似文献
15.
16.
17.
Giuseppe BattistoniFrancesco Broggi Markus BruggerMauro Campanella Massimo CarboniAnton Empl Alberto FassòEttore Gadioli Francesco CeruttiAlfredo Ferrari Anna FerrariMatthias Lantz Andrea MairaniM. Margiotta Cristina MoroneSilvia Muraro Katia ParodiVincenzo Patera Mauricio PelliccioniLarry Pinsky Johannes RanftStefan Roesler Sofia RolletPaola R. Sala Mario SantanaLucia Sarchiapone Massimiliano SioliGeorge Smirnov Florian SommererChristian Theis Stefania TrovatiR. Villari Heinz VinckeHelmut Vincke Vasilis Vlachoudis Joachim VollaireNeil Zapp 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(24):2850-2856
18.
Polycarbonate‐based composites reinforced by in situ polytetrafluoroethylene fibrillation: Preparation,thermal and rheological behavior 下载免费PDF全文
Diego Antonioli Katia Sparnacci Michele Laus Luca Boarino Maria Cristina Righetti 《应用聚合物科学杂志》2015,132(32)
Fibrillar reinforced composites of polytetrafluoroethylene (PTFE) and polycarbonate (PC) were prepared by in situ fibrillation of PTFE into PC matrix using twin screw extruder. Different samples were obtained by varying the relative ratio between PC and PTFE. The rheological properties of the PC/PTFE composites were found to depend on concentration of the PTFE fibrils. The melt strength analysis in nonisothermal conditions was also studied. The increase in force and decrease in drawability with increasing the PTFE content are associated with the PTFE fibrils formed in situ during the thermomechanical process in twin screw extruder. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42401. 相似文献
19.
Helio Fiori de Castro Katia Lucchesi Cavalca Lucas Ward Franco de Camargo Nicoló Bachschmid 《Mechanical Systems and Signal Processing》2010,24(6):1785-1798
This paper discusses the identification of parameters in rotary systems, namely, the unbalance magnitude, phase and position in the rotor system. These parameters can be identified using the measured orbits in the hydrodynamic bearings. The oil film forces are evaluated in the different positions of the orbit of the journal and are applied to the model of the shaft. The model, integrated in time domain, allows with an assumed unbalance, to simulate the orbits. The objective function is basically the difference between measured and simulated orbits, and its minimum corresponds to the identified unbalance amount, phase and position along the shaft. With respect to traditional model based identification procedures, this approach using oil film forces instead of oil film linearized stiffness and damping coefficients, and unfiltered orbits instead of 1X vibration components is suitable to deal with non-linear behaviour of the system. 相似文献
20.