全文获取类型
收费全文 | 352篇 |
免费 | 13篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 122篇 |
金属工艺 | 10篇 |
机械仪表 | 6篇 |
建筑科学 | 15篇 |
能源动力 | 16篇 |
轻工业 | 22篇 |
水利工程 | 3篇 |
石油天然气 | 9篇 |
无线电 | 26篇 |
一般工业技术 | 66篇 |
冶金工业 | 19篇 |
原子能技术 | 1篇 |
自动化技术 | 48篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 14篇 |
2021年 | 14篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 24篇 |
2017年 | 12篇 |
2016年 | 17篇 |
2015年 | 9篇 |
2014年 | 16篇 |
2013年 | 36篇 |
2012年 | 13篇 |
2011年 | 14篇 |
2010年 | 17篇 |
2009年 | 22篇 |
2008年 | 12篇 |
2007年 | 15篇 |
2006年 | 10篇 |
2005年 | 6篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1970年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有367条查询结果,搜索用时 0 毫秒
51.
Gomaa Hosam M. Zahran H. Y. Yahia I. S. 《Journal of Materials Science: Materials in Electronics》2021,32(16):21135-21154
Journal of Materials Science: Materials in Electronics - A set of glasses composed of seven samples was prepared using the fast cooling mechanism for glass preparation. The synthesis processes... 相似文献
52.
Hapipi Nurhidayah Mohd Chen Soo Kien Shaari Abdul Halim Kechik Mohd Mustafa Awang Lim Kean Pah Tan Kar Ban Lee Oon Jew Arvapalli Sai Srikanth Miryala Muralidhar 《Journal of Materials Science: Materials in Electronics》2022,33(14):11269-11270
Journal of Materials Science: Materials in Electronics - 相似文献
53.
Waste polyurethane foam (w‐PU) and waste ethylene–vinyl acetate foam (w‐EVA) were used as fillers for the production of an ethylene–vinyl acetate (EVA) blend foam. Two different foaming techniques (single‐stage and heat–chill processes) were used for this purpose. The waste foam concentration was varied up to 30 wt % of the original EVA. The physical, mechanical, and morphological properties of the filled foam were studied. The single‐stage process produced blend foams with a lower density and a greater cell size than the foams obtained by the heat–chill process. The density and compression strength of the blend foam increased as the percentage of w‐PU foam increased. However, for the w‐EVA/EVA blend foams, the addition of w‐EVA foam did not significantly affect the density or compression strength compared to the original EVA foams. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44708. 相似文献
54.
Interest in ecological design issues has increased enormously over the past few decades and ecological problems are perceived to be on the increase. This paper seeks to investigate the relative importance of the design eco-drivers contributing to ecological building design (EBD) success in the UK. A large number of eco-drivers have been extracted from literature and current design practices. To compare views from architects, data were collected from a statistically significant number of practising architects in the area of sustainable design. The data collected represent the views and ambitions of surveyed architects and not necessarily their current design practices. Ranking techniques are utilised to identify the connotation of eco-design indicators. Based on this analysis, the most important eco-design drivers are extracted. From the results of the overall ranking 'energy, efficiency, energy consumption, energy-eco-efficiency and environmentally adapted technology', eco-drivers are ranked as the most important factors amongst others. This indicates that the surveyed architects strongly perceive ecological design as being driven by energy aspects of building assets. This suggests that these findings are more sensitive to respondents' perception rather than to actual design practices. The selected eco-indicators could be used to assist designers in carrying out ecological design contextual synthesis as well as developing ecological design strategies. 相似文献
55.
Joseph Halim Sankalp Kota Maria R. Lukatskaya Michael Naguib Meng‐Qiang Zhao Eun Ju Moon Jeremy Pitock Jagjit Nanda Steven J. May Yury Gogotsi Michel W. Barsoum 《Advanced functional materials》2016,26(18):3118-3127
Large scale synthesis and delamination of 2D Mo2CT x (where T is a surface termination group) has been achieved by selectively etching gallium from the recently discovered nanolaminated, ternary transition metal carbide Mo2Ga2C. Different synthesis and delamination routes result in different flake morphologies. The resistivity of free‐standing Mo2CT x films increases by an order of magnitude as the temperature is reduced from 300 to 10 K, suggesting semiconductor‐like behavior of this MXene, in contrast to Ti3C2T x which exhibits metallic behavior. At 10 K, the magnetoresistance is positive. Additionally, changes in electronic transport are observed upon annealing of the films. When 2 μm thick films are tested as electrodes in supercapacitors, capacitances as high as 700 F cm?3 in a 1 m sulfuric acid electrolyte and high capacity retention for at least 10,000 cycles at 10 A g?1 are obtained. Free‐standing Mo2CT x films, with ≈8 wt% carbon nanotubes, perform well when tested as an electrode material for Li‐ions, especially at high rates. At 20 and 131 C cycling rates, stable reversible capacities of 250 and 76 mAh g?1, respectively, are achieved for over 1000 cycles. 相似文献
56.
57.
Nanocrystallite iron oxide powders with different crystallite sizes were prepared by co-precipitation route. The prepared powders with crystallite size 75, 100 and 150 nm together with commercial iron oxide (250 nm) were tested for the catalytic oxidation of CO to CO2. The influence of different factors as crystallite size, catalytic temperature and weight of catalyst on the rate of catalytic reaction was investigated using advanced quadrupole mass gas analyzer system. It can be reported that the rate of conversion of CO to CO2 increased by increasing catalytic temperature and decreasing crystallite size of the prepared powders. The experimental results show that nanocrystallite iron oxide powders with crystallite size 75 nm can be recommended as a promising catalyst for CO oxidation at 500 °C where 98% of CO is converted to CO2. The mechanism of the catalytic oxidation reaction was investigated by comparing the CO catalytic oxidation data in the absence and presence of oxygen. The reaction which was found to be first order with respect to CO is probably proceeded by adsorption mechanism where the reactants are adsorbed on the surface of the catalyst with breaking OO bonds, then CO pick up the dissociated O atom forming CO2. 相似文献
58.
Building construction takes time, in part because the binding process of cement is based on the slow re-crystallization and precipitation of calcium silicate species. Since the material's reactivity is surface area limited, a reduction in particle size of Portland cements has been used to prepare faster binding formulations. The present work investigates a new and direct, one-step preparation of calcium silicate-based nanoparticles of a typical Portland cement composition by flame spray synthesis. Isothermal calorimetry revealed that the hardening of this new nano-cement corroborated a more than tenfold increase of initial reactivity with different reaction kinetics if compared to conventionally prepared cements. At present, the unfavourably high porosity of nano-cements, however, underlines the need for additional improvements of chemical composition and formulation to make these highly reactive materials applicable to modern construction work, where load-bearing strength is of importance. 相似文献
59.
Julien Vitry Guillaume Par Andra Murru Xavier Charest-Morin Halim Maaroufi Kenneth R. McLeish Paul H. Naccache Maria J. Fernandes 《International journal of molecular sciences》2021,22(19)
CLEC12A is a myeloid inhibitory receptor that negatively regulates inflammation in mouse models of autoimmune and autoinflammatory arthritis. Reduced CLEC12A expression enhances myeloid cell activation and inflammation in CLEC12A knock-out mice with collagen antibody-induced or gout-like arthritis. Similarly to other C-type lectin receptors, CLEC12A harbours a stalk domain between its ligand binding and transmembrane domains. While it is presumed that the cysteines in the stalk domain have multimerisation properties, their role in CLEC12A expression and/or signaling remain unknown. We thus used site-directed mutagenesis to determine whether the stalk domain cysteines play a role in CLEC12A expression, internalisation, oligomerisation, and/or signaling. Mutation of C118 blocks CLEC12A transport through the secretory pathway diminishing its cell-surface expression. In contrast, mutating C130 does not affect CLEC12A cell-surface expression but increases its oligomerisation, inducing ligand-independent phosphorylation of the receptor. Moreover, we provide evidence that CLEC12A dimerisation is regulated in a redox-dependent manner. We also show that antibody-induced CLEC12A cross-linking induces flotillin oligomerisation in insoluble membrane domains in which CLEC12A signals. Taken together, these data indicate that the stalk cysteines in CLEC12A differentially modulate this inhibitory receptor’s expression, oligomerisation and signaling, suggestive of the regulation of CLEC12A in a redox-dependent manner during inflammation. 相似文献
60.
Radiation graft copolymerization of comonomer mixtures of acrylic acid (AAc) and styrene (S) onto polypropylene (PP) films by the mutual method has been investigated. The effect of different factors that may affect the grafting yield, such as inhibitor concentration (Mohr’s salt), solvent composition (MeOH and H2O), radiation dose and dose rate, was studied. It was found that Mohr’s salt was very effective when the content of AAc in the comonomer mixtures was low. However, the addition of 1·25wt% of Mohr’s salt reduced homopolymer formation and enhanced the grafting process. Graft copolymerization in the presence of a solvent mixture composed of methanol and water was found to afford a higher grafting yield than in pure methanol, regardless of the composition of the comonomer mixture used. However, the highest degree of grafting was obtained at a solvent composition of 20% H2O: 80% MeOH and a comonomer mixture of 20% AAc: 80% S. An attempt was made to determine each PAAc and PS fraction by different methods in the graft copolymer obtained. Elemental analysis indicated that the PAAc fraction with respect to PS in the graft copolymer decreased with increasing AAc ratio in the comonomer feed solution. The rough assessment of these fractions by IR spectroscopy showed similar trends. The reactivity ratios of AAc and S monomers determined in the present graft copolymerization system were found to be 0·45 and 1·3, respectively. © of SCI. 相似文献