全文获取类型
收费全文 | 148篇 |
免费 | 4篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 1篇 |
综合类 | 2篇 |
化学工业 | 28篇 |
金属工艺 | 12篇 |
机械仪表 | 1篇 |
建筑科学 | 2篇 |
能源动力 | 7篇 |
轻工业 | 13篇 |
水利工程 | 1篇 |
石油天然气 | 13篇 |
无线电 | 19篇 |
一般工业技术 | 16篇 |
冶金工业 | 22篇 |
自动化技术 | 18篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 12篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 11篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 9篇 |
2004年 | 7篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有155条查询结果,搜索用时 15 毫秒
11.
Raffaele Sacchi Isabel Medina Santiago P. Aubourg Francesco Addeo Livio Paolillo 《Journal of the American Oil Chemists' Society》1993,70(3):225-228
Based on proton nuclear magnetic resonance (1H-NMR) spectroscopy, a rapid and structure-specific method for the determination of ω-3 polyunsaturated fatty acids (PUFAs)
in fish lipids is presented. The different chemical shift observed for the methyl resonance of ω-3 PUFAs (δ=0.95 ppm) with
respect to the methyl resonance of all other fatty acids (δ=0.86 ppm) has provided the possibility of proposing a new and
rapid method for the determination of ω-3 PUFA content. Twenty-four fish lipid samples (raw, cooked and canned albacore tuna)
produced results that showed good agreement between1H-NMR analysis and gas chromatographic determination. Raw and cooked samples showed significantly higher levels of ω-3 PUFA
than canned tuna. 相似文献
12.
For manufacturing the magnets of fusion machines pure copper of both high mechanical resistance and electrical conductivity is required. Though high purity copper guarantees high electrical conductivity, its mechanical properties may be not suitable for the applications in tokamaks. In this view, a new procedure developed for obtaining high purity copper with excellent mechanical strength is described in this work. Samples of oxygen free copper (OFC) have been worked by pressing in liquid nitrogen (77 K). It has been verified that the mechanical properties of the worked metal are strongly dependent on the strain rate. Very low strain rates permitted to attain values of tensile yield strength (550 MPa) significantly higher than those obtained by traditional cold-working at room temperature (450 MPa). The electrical conductivity of the cryo-worked Cu decreases with the tensile yield strength even though the hardest samples of tensile yield strength of 550 MPa exhibit still acceptable values of conductivity (about 94 % IACS at room temperature). 相似文献
13.
微光像增强器是微光成像系统的核心部分,其成像质量决定了对微弱光学信号的探测能力.像增强器的调制传递函数(modulation transfer function,MTF)反映了系统对图像不同频率成分的传递能力,是像质评定的一种客观指标.本文基于狭缝法测试MTF的原理,进行系统校准和采用分段加权最小二乘拟合实现曲线的平滑去噪,构建了微光像增强器的MTF测试系统.具体是采用十字狭缝靶标进行测试得到线扩散函数(line spread function,LSF)曲线,然后对其进行去噪处理和离散傅里叶变换得到MTF曲线,测试结果与德国OEG-2MTF测试仪比较,误差率低于5%,为研制高成像质量微光像增强器提供了一种有效评价手段. 相似文献
14.
A double-gate (DG) fin field effect transistor (FinFET) is discussed as new label-free ion and biological sensor. Simulations as function of channel doping, geometrical dimensions, operation point and materials investigated the device response to an external potential difference which provides a body threshold voltage modulation. The simulation results presented in this work clearly state the key features for an ultrasensitive FET based sensor: an enhancement low doped and partially gated transistor operating in weak-moderate inversion regime. The optimized sensitivity, obtained when the width of the fin is equal to the gate height (wNW ∼ hg), reaches a value of 85% for an extraction current, Id, of 0.1 μA. These results pave the way for the fabrication process of an innovative CMOS compatible sensing system. 相似文献
15.
Classical molecular dynamics studies of carbon ion-irradiation on ropes made of (10, 10) carbon nanotubes have been made. The carbon ions were fired into the rope on the outside of the nanotubes in a direction almost parallel to the longitudinal axis. Channeling takes place when the incidence angle is smaller than a critical angle. The dependence of the critical angle on the energy follows an inverse square root function. Our calculations show that the dependence of the critical angle on the energy is very similar for intra- and inter-tube channeling. Wave creation during the collision process is discussed. 相似文献
16.
17.
Joaquim P. Cardoso Martin F. Chaplin A. Nicholas Emery John F. Kennedy Livio P. Revel-Chion 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1978,28(11):775-783
Methods are described for the immobilisation of enzymes on inorganic supports activated by the surface deposition of an imperfectly crystallised film of TiO2. The stability of the preparations is shown to be strongly dependent on the integrity of the support-TiO2 link which is in turn dependent on the pretreatment of the solid support. The enzyme may be linked to the activated support using 5-aminosalicylic acid (with or without diazotisation), tannic acid or stannous chloride, or by direct contact. These preparations are shown to have activities and operational stabilities superior to those of a preparation made using the silane-glutaraldehyde method on the same glass support. 相似文献
18.
Livio?CricelliEmail author Francesca?Di?Pillo Massimo?Gastaldi Nathan?Levialdi 《Networks and Spatial Economics》2005,5(3):261-277
In the last ten years, the international telecommunications industry has undergone important changes from both the legislative (regulatory reforms) and the technological points of view. The liberalization of the telecommunications market has, consequently, affected the dynamics of the bilateral agreements between international carriers. In this paper, the international wholesale market in which carriers compete over the tariffs in order to increase their market share is analyzed. In particular, this paper examines the interactions between fixed telephony TLC carriers belonging to various countries and analyzes the possible strategic choices of the market leader induced by changes in competitor behavior. 相似文献
19.
Pamela Senesi Anna Ferrulli Livio Luzi Ileana Terruzzi 《International journal of molecular sciences》2021,22(15)
Type 2 diabetes (T2DM) and cardiovascular disease (CVD) are closely associated and represent a key public health problem worldwide. An excess of adipose tissue, NAFLD, and gut dysbiosis establish a vicious circle that leads to chronic inflammation and oxidative stress. Caloric restriction (CR) is the most promising nutritional approach capable of improving cardiometabolic health. However, adherence to CR represents a barrier to patients and is the primary cause of therapeutic failure. To overcome this problem, many different nutraceutical strategies have been designed. Based on several data that have shown that CR action is mediated by AMPK/SIRT1 activation, several nutraceutical compounds capable of activating AMPK/SIRT1 signaling have been identified. In this review, we summarize recent data on the possible role of berberine, resveratrol, quercetin, and L-carnitine as CR-related nutrients. Additionally, we discuss the limitations related to the use of these nutrients in the management of T2DM and CVD. 相似文献
20.