全文获取类型
收费全文 | 661篇 |
免费 | 13篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 21篇 |
综合类 | 1篇 |
化学工业 | 123篇 |
金属工艺 | 28篇 |
机械仪表 | 7篇 |
建筑科学 | 21篇 |
能源动力 | 23篇 |
轻工业 | 50篇 |
水利工程 | 9篇 |
石油天然气 | 4篇 |
无线电 | 42篇 |
一般工业技术 | 146篇 |
冶金工业 | 153篇 |
原子能技术 | 12篇 |
自动化技术 | 35篇 |
出版年
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 5篇 |
2019年 | 10篇 |
2018年 | 11篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 6篇 |
2014年 | 19篇 |
2013年 | 47篇 |
2012年 | 33篇 |
2011年 | 27篇 |
2010年 | 33篇 |
2009年 | 40篇 |
2008年 | 20篇 |
2007年 | 21篇 |
2006年 | 20篇 |
2005年 | 20篇 |
2004年 | 20篇 |
2003年 | 13篇 |
2002年 | 9篇 |
2001年 | 8篇 |
2000年 | 12篇 |
1999年 | 20篇 |
1998年 | 56篇 |
1997年 | 25篇 |
1996年 | 28篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 14篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 11篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1971年 | 4篇 |
1970年 | 3篇 |
排序方式: 共有675条查询结果,搜索用时 500 毫秒
101.
Makoto Okada Masayuki Iwasa Ken-ichiro Nakamatsu Kazuhiro Kanda Yuichi Haruyama Shinji Matsui 《Microelectronic Engineering》2009,86(4-6):673-675
A fluorinated self-assembled monolayer (F-SAM) is mainly used as the antisticking layer. To prevent the F-SAM coated on the nanoimprint lithography (NIL) mold from deteriorating, we propose a new form of nanoimprinting using a release-agent-coated resin. The results from measuring the surface free energy and observations by scanning probe microscopy (SPM) confirmed that the surface free energy, frictional force, and adhesion force of the release-agent spray-coated polymethylmethacrylate (PMMA) were lower than those of PMMA. To prove the release-agent spray-coated PMMA had a releasing effect, we tried to undertake thermal nanoimprinting on it using a mold without F-SAM. The pattern was clearly imprinted on the resin without any signs of adhesion. 相似文献
102.
Satoshi Suzuki Mari Fukuoka Hikaru Ookuchi Motoaki Sano Kenji Ozeki Emi Nagayoshi Yukio Takii Mayumi Matsushita Sawaki Tada Ken-Ichi Kusumoto Yutaka Kashiwagi 《Journal of Bioscience and Bioengineering》2010,109(2):115-117
This is the first report of glycoside hydrolase family 43 β-xylosidase from Aspergillus oryzae. To characterize this enzyme, the recombinant enzyme was expressed in Escherichia coli. Unlike known β-xylosidases from fungal origins, the enzyme did not show substrate ambiguity and was stable at alkaline pH. 相似文献
103.
Dalia Heggo Shinichi Ookawara Teruhisa Ohno Toru Nakai Yoshihisa Matsushita Mona Gamal Eldin Masahiro Ohshima 《加拿大化工杂志》2020,98(1):119-126
Dense photocatalyst slurry was employed for the synthesis of p-anisaldehyde under solar light irradiation. An Fe-modified rutile TiO 2 (Fe-TiO 2, 34.5 m 2/g) photocatalyst was used as a visible-light-responsive photocatalyst. A conventional TiO 2 (P25, 35 m 2/g) photocatalyst was also examined as a reference catalyst. XRD patterns and diffuse reflectance spectra showed that Fe-TiO 2 consists of 100 % rutile phase and absorbs more visible light compared to P25, respectively. The catalyst powder was suspended in an ethyl acetate solution of p-methoxytoluene in the mini-reactor, with oxygen bubbling, under a solar simulator, visible light, and UV LEDs. p-anisaldehyde, as a reaction product, was analyzed by sampling using gas-chromatograph. Regardless of the light source, Fe-TiO 2 always outperformed P25 in terms of both generation rates (GR) of p-anisaldehyde and energy requirements (ER). It was demonstrated that the highly dense Fe-TiO 2 slurry was efficient for the synthesis under solar light owing to the small size of the reactor. The small amount of Pt and ZrO 2 cocatalysts significantly enhanced the GR under solar light. By adopting a visible light responsive Fe-TiO 2 photocatalyst, the mini slurry-bubble reactor under solar light achieved a high GR per catalyst mass (CM), which is one to two orders higher than that reported by most previous studies with high-power lamps. 相似文献
104.
105.
Solar Cells: Self‐Organized Superlattice and Phase Coexistence inside Thin Film Organometal Halide Perovskite (Adv. Mater. 8/2018) 下载免费PDF全文
106.
Mohammad Nurunnabi Baitao Li Kimio Kunimori Kimihito Suzuki Ken-ichiro Fujimoto Keiichi Tomishige 《Catalysis Letters》2005,103(3-4):277-281
The addition of Pt on NiO–MgO solid solution enhanced the performance of oxidative steam reforming of methane, especially, the catalyst can be activated during the oxidative reforming of methane at low reaction temperature like 823 K. 0.1% Pt/Ni0.2Mg0.8O exhibited much higher performance than 0.1% Pt/MgO and Ni0.2Mg0.8O. From the comparisons, the additive effect of Pt to Ni0.2Mg0.8O is to promote both the activity of combustion and reforming of methane. This additive effect can be explained by the high combustion activity caused by the synergy of Pt with NiO–MgO solid solution and the high catalyst reducibility. 相似文献
107.
A. D. Andrade A. F. Rubira M. Matsushita N. E. Souza 《Journal of the American Oil Chemists' Society》1995,72(10):1207-1210
Lipid and fatty acid levels in the edible flesh of 17 freshwater fish from Brazil’s southern region were determined. Analyses
of fatty acid methyl esters were performed by gas chromatography. Palmitic acid (C16:0) was the predominant saturated fatty acid, accounting for 50–70% of total saturated acids. Oleic acid (C18:1θ9) was the most abundant monounsaturated fatty acid. Linoleic acid (C18:2θ6), linolenic acid (C18:3θ3), and docosahexaenoic acid (C22:6θ3) were the predominant polyunsaturated fatty acids (PUFA). The data revealed that species such as truta, barbado, and corvina
were good sources of eicosapentaenoic acid (C20:5θ3) and docosahexaenoic acid (C22:6θ3), and that most freshwater fish examined were good sources of PUFA θ3. 相似文献
108.
Pitting corrosion is typical corrosion observed on coated hold frames in way of cargo holds of bulk carriers, which exclusively carry coal and iron ore. Extensive survey on the effect of pitting corrosion on structural strength under a wide variety of loading conditions is necessary to clarify the relationship between pitting intensity and residual strength in detail. In the present study, a series of tests has been conducted on structural models which consist of web, shell and face plates to investigate the effect of pitting corrosion on strength of web plates subjected to patch loading. In these tests, artificial pitting was made on the web plates and two equal concentrated loads have been applied vertically at the one third points of simply supported models. It was found that web crippling behavior is strongly affected by the pit distribution on the web plates. According to the FE-analyses following the experiment, ultimate strength of the web plates with pitting under patch loading is a little smaller than or almost the same as that of the web plates with uniform corrosion in terms of average thickness loss. 相似文献
109.
H Matsushita M Hara Y Endo Y Shishiba S Hara Y Ubara H Nakazawa N Suzuki K Kawaminami T Kido Q Li L Grimelius 《Canadian Metallurgical Quarterly》1999,55(1):130-138
BACKGROUND: Parathyroid hormone-related protein (PTHrP) is now suspected to act as an autocrine or paracrine regulator of cell growth or differentiation, although it was originally reported as a hypercalcemic substance in malignancies. This study was performed to assess the relationship between PTHrP expression and cell proliferation in human parathyroid glands. METHODS: The localization of PTH and PTHrP was studied in 42 samples of hyperplastic parathyroid from 14 long-term hemodialysis cases with immunohistochemistry and in situ hybridization. Results were compared with proliferative activity (proliferating cell nuclear antigen index: counts of proliferating cell nuclear antigen-positive cells/100 cells). The localization of the PTH/PTHrP receptor was also examined. Ten normal glands were studied as controls. RESULTS: In hyperplasia, cells positive for PTH, PTHrP, or both were observed immunohistochemically. The areas expressing PTHrP mRNA completely coincided with those positive for PTHrP immunohistochemically. Oxyphilic or transitional oxyphilic cells were consistently positive for PTHrP. PTH/PTHrP receptors were located in the cytoplasmic membrane in most parathyroid cells. Proliferating cell nuclear antigen-positive cells were rare in normal glands with an index of 0. 22 +/- 0.09 (mean +/- sem). They were significantly increased in hyperplastic cases but less for PTHrP-positive than for -negative cells (1.25 +/- 0.16 as compared with 7.80 +/- 0.52; P < 0.0001). CONCLUSION: The observed low level of proliferation of PTHrP-positive cells suggests a functional role for PTHrP as a possible growth suppressor in the human parathyroid. 相似文献
110.
Efficient and Handy Texture Mapping on 3D Surfaces 总被引:2,自引:0,他引:2
There has been a rapid technical progress in three-dimensional (3D) computer graphics. But gathering surface and texture data is yet a laborious task. This paper addresses the problem of mapping photographic images on the surface of a 3D object whose geometric data are already known. We propose an efficient and handy method for acquiring textures and mapping them precisely on the surface, employing a digital camera alone. We describe an algorithm for selecting a minimal number of camera positions that can cover the entire surface of a given object and also an algorithm to determine camera's position and direction for each photograph taken so as to paste it to the corresponding surfaces precisely. We obtained a matching accuracy within a pixel on a surface through three experimental examples, by which the practicability of our method is demonstrated. 相似文献