全文获取类型
收费全文 | 235篇 |
免费 | 7篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 45篇 |
金属工艺 | 2篇 |
机械仪表 | 6篇 |
建筑科学 | 7篇 |
能源动力 | 6篇 |
轻工业 | 36篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 17篇 |
一般工业技术 | 38篇 |
冶金工业 | 31篇 |
原子能技术 | 1篇 |
自动化技术 | 49篇 |
出版年
2022年 | 8篇 |
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 9篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 22篇 |
2011年 | 17篇 |
2010年 | 15篇 |
2009年 | 11篇 |
2008年 | 10篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有242条查询结果,搜索用时 156 毫秒
21.
The present study analyzed the antioxidative effects of various beverages, in vitro, and also the effect of short term consumption of beverages richest in polyphenols by healthy subjects on serum anti-atherogenic properties. Healthy subjects consumed 250 mL of the selected beverages for 2 h, or daily, for up to 1 week.We hypothesized that differences in the anti-atherogenic properties of the studied beverages could be related, not only to the quantity of polyphenols, but also to their quality. Furthermore, we hypothesized that consumption of these juices by healthy subjects for just a short-term, will increase their serum anti-atherogenic properties, as was demonstrated previously in long-term consumption studies.Of 35 beverages studied, both 100% Wonderful-variety pomegranate and 100% black currant juices were the most potent antioxidants in vitro, as they inhibited copper ion-induced LDL oxidation by up to 94% and AAPH-induced serum lipid peroxidation by up to 38%. Furthermore, they increased in vitro serum paraoxonase 1 (PON1) lactonase activity by up to 51%. Consumption of five selected polyphenol rich beverages by healthy subjects increased serum sulfhydryl group (SH) levels and serum PON1 activities after 2 h, and more so after 1 week of drinking these beverages. These effects were most pronounced after the consumption of 100% Wonderful-variety pomegranate and 100% black currant juices. In conclusion, polyphenolic-rich juices with impressive in vitro antioxidant properties, also demonstrate antioxidant effects in vivo when analyzed for short term consumption. In this respect, 100% Wonderful-variety pomegranate and 100% black currant juices were most the potent. 相似文献
22.
In this paper, waste clay was cured with ethyl acetate to obtain treated clay(TC), which was modified with gallic acid to obtain a low-cost sorbent that was characterized by EDX, SEM, and FTIR analysis. Uranium(Ⅵ) adsorption was achieved using the batch adsorption method on the TC and gallic acid-modified treated clay(GMTC). The maximum uptakes of U(Ⅵ) on TC and GMTC were 37.2 and 193.0 mg/g, respectively.The U(Ⅵ) adsorption kinetics on the TC and GMTC sorbents were well-fitted by the pseudo-second-order mechanism, and the adsorption equilibrium followed the Langmuir model. The optimum parameters were applied to El Sela leach solution for uranium recovery. 相似文献
23.
24.
High-quality uniform dry transfer of graphene to polymers 总被引:1,自引:0,他引:1
Lock EH Baraket M Laskoski M Mulvaney SP Lee WK Sheehan PE Hines DR Robinson JT Tosado J Fuhrer MS Hernández SC Walton SG 《Nano letters》2012,12(1):102-107
In this paper we demonstrate high-quality, uniform dry transfer of graphene grown by chemical vapor deposition on copper foil to polystyrene. The dry transfer exploits an azide linker molecule to establish a covalent bond to graphene and to generate greater graphene-polymer adhesion compared to that of the graphene-metal foil. Thus, this transfer approach provides a novel alternative route for graphene transfer, which allows for the metal foils to be reused. 相似文献
25.
Hopkins PE Baraket M Barnat EV Beechem TE Kearney SP Duda JC Robinson JT Walton SG 《Nano letters》2012,12(2):590-595
Graphene-based devices have garnered tremendous attention due to the unique physical properties arising from this purely two-dimensional carbon sheet leading to tremendous efficiency in the transport of thermal carriers (i.e., phonons). However, it is necessary for this two-dimensional material to be able to efficiently transport heat into the surrounding 3D device architecture in order to fully capitalize on its intrinsic transport capabilities. Therefore, the thermal boundary conductance at graphene interfaces is a critical parameter in the realization of graphene electronics and thermal solutions. In this work, we examine the role of chemical functionalization on the thermal boundary conductance across metal/graphene interfaces. Specifically, we metalize graphene that has been plasma functionalized and then measure the thermal boundary conductance at Al/graphene/SiO(2) contacts with time domain thermoreflectance. The addition of adsorbates to the graphene surfaces are shown to influence the cross plane thermal conductance; this behavior is attributed to changes in the bonding between the metal and the graphene, as both the phonon flux and the vibrational mismatch between the materials are each subject to the interfacial bond strength. These results demonstrate plasma-based functionalization of graphene surfaces is a viable approach to manipulate the thermal boundary conductance. 相似文献
26.
Sergio Scudino Kumar Babu Surreddi Mohsen Samadi Khoshkhoo Mira Sakaliyska Gang Wang Jürgen Eckert 《Advanced Engineering Materials》2010,12(11):1123-1126
In this work, the effect of channel‐die compression (CDC) on the mechanical behavior of the Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass is analyzed. The results indicate that CDC can be successfully used as a pre‐deformation process to effectively enhance the room temperature plastic strain ability of metallic glasses. The origin of the improved mechanical properties is most likely due to the creation during CDC of a heterogenous microstructure consisting of hard and soft regions able to hinder the rapid propagation of shear bands. 相似文献
27.
Mira Park Byoung-Suhk Kim Hye Kyoung Shin Soo-Jin Park Hak-Yong Kim 《Materials science & engineering. C, Materials for biological applications》2013,33(8):5051-5057
The biocompatible and highly porous keratin-based hydrogels were prepared using electron beam irradiation (EBI). The conditions for keratin-based hydrogel formation were investigated depending on several conditions, including the presence of poly(vinyl alcohol) (PVA), concentration of keratin solution, EBI dose, and poly(ethylene imine) (PEI) additives. The pure keratin (human hair and wool) aqueous solution was not gelled by EBI, while the aqueous keratin solutions blended with PVA were gelled at an EBI dose of more than 90 kGy. Furthermore, in the presence of PEI, the aqueous keratin solution blended with PVA could be gelled at a considerably lower EBI dose, even at 10 kGy. This finding suggests that the PEI additives significantly influence the rate of gelation and that PEIs function as an accelerator during gelation. The resulting keratin-based hydrogels were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), gel fraction, degree of swelling, gel strength, and kinetics of swelling analyses. 相似文献
28.
29.
30.
The aim of this study was to evaluate the antioxidant mechanisms of red ginseng essential oil (REO) in cells as well as in an animal model. REO was prepared by a supercritical CO(2) extraction of waste-products generated after hot water extraction of red ginseng. In HepG2 cells, REO diminished the H(2)O(2)-mediated oxidative stress and also restored both the activity and expression of antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase. Administration of REO inhibited the phosphorylation of upstream mitogen-activated protein kinases (MAPKs) such as c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38. In mice, the CCl(4)-mediated elevation of serum aspartate transaminase and alanine transaminase as well as the induction of hepatic lipid peroxidation were decreased by REO administration. REO treatments also resulted in up-regulation of the antioxidant enzyme expression in the liver. Moreover, increased phosphorylations of MAPKs were inhibited after REO administration. Overall, REO seems to protect the liver from oxidative stress through the activation and induction of antioxidant enzymes via inhibition of MAPKs pathways. 相似文献