全文获取类型
收费全文 | 289篇 |
免费 | 15篇 |
专业分类
电工技术 | 10篇 |
化学工业 | 82篇 |
金属工艺 | 8篇 |
机械仪表 | 5篇 |
建筑科学 | 17篇 |
能源动力 | 9篇 |
轻工业 | 32篇 |
水利工程 | 5篇 |
无线电 | 23篇 |
一般工业技术 | 53篇 |
冶金工业 | 35篇 |
原子能技术 | 8篇 |
自动化技术 | 17篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 11篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 8篇 |
2014年 | 7篇 |
2013年 | 21篇 |
2012年 | 14篇 |
2011年 | 26篇 |
2010年 | 19篇 |
2009年 | 17篇 |
2008年 | 8篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 6篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 11篇 |
1999年 | 6篇 |
1998年 | 11篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有304条查询结果,搜索用时 15 毫秒
61.
Kengo Yoshida Renald BrennerBrigitte Bacroix Salima Bouvier 《Materials Science and Engineering: A》2011,528(3):1037-1046
Work-hardening behavior of single-phase steel and dual-phase steel which is made of hard martensite surrounded by soft ferrite is analyzed by using an elastoplastic crystal plasticity model in conjunction with the incremental self-consistent model. Two-stage loading paths consisting of uniaxial tension, unloading and subsequent uniaxial tension/compression for various directions are applied. Bauschinger effect and transitional re-yielding behavior, which depends on the direction of the second loading path, are predicted and analyzed with respect to the distribution of the residual resolved shear stresses within the material. These features, which are caused by the inhomogeneity of the residual stress field, are especially pronounced in the case of the dual-phase steel because of the strong mechanical contrast between ferrite and martensite phases. 相似文献
62.
63.
Kengo Matsumoto 《Dynamical Systems: An International Journal》2017,32(3):423-459
λ-Graph systems are labelled Bratteli diagrams with shift operations. They present subshifts. Their matrix presentations are called symbolic matrix systems. We define skew products of λ-graph systems and study extensions of subshifts by finite groups. We prove that two canonical symbolic matrix systems are G-strong shift equivalent if and only if their presented subshifts are G-conjugate. 相似文献
64.
K Jin-no M Tanimizu I Hyodo Y Nishikawa Y Hosokawa H Endo T Doi K Mandai H Ishitsuka 《Canadian Metallurgical Quarterly》1998,82(7):1260-1267
BACKGROUND: Platelet-derived endothelial cell growth factor (PD-ECGF) is an angiogenic factor that is expressed in various cancer tissues. Little is known regarding plasma PD-ECGF levels in patients with chronic liver disease such as chronic hepatitis (CH), cirrhosis, and hepatocellular carcinoma (HCC) with cirrhosis. The expression of PD-ECGF in HCC tissues also remains to be clarified. METHODS: Plasma PD-ECGF levels in patients with chronic liver disease were determined with an enzyme-linked immunoadsorbent assay system using the mouse monoclonal antibodies specific to PD-ECGF. These were cross-sectionally compared among groups of normal persons, CH, cirrhosis, and HCC patients. The HCC patients were classified into two groups based on TNM stage: early and advanced stage disease groups. PD-ECGF expressions in HCC tissues were immunohistologically examined. RESULTS: The plasma PD-ECGF levels from the normal individuals and those with CH, cirrhosis, and HCC specimens were 4.2+/-0.5, 4.3+/-0.6, 4.6+/-1.1, and 6.0 +/-2.5 U/mL, respectively. The plasma PD-ECGF concentration was highest in HCC (P < 0.05). No significant difference was found among the normal subjects, CH, and cirrhosis specimens. Plasma PD-ECGF concentrations were significantly higher in the advanced stage disease HCC group compared with the early stage disease group (6.75+/-2.62 U/mL vs. 4.19+/-0.34 U/mL) (P < 0.05). Immunohistochemical expression of PD-ECGF in HCC cells increased significantly compared with normal liver cells (P < 0.05). CONCLUSIONS: Circulating PD-ECGF plasma level might be a new tumor marker for progression in patients with HCC. Immunohistological findings correspond to elevation of the plasma PD-ECGF in HCC patients. It is possible that increased production of PD-ECGF in HCC cells causes abundant neovascularization. 相似文献
65.
M Tanaka T Hakuto M Akatsuka E Morimoto T Hama M Morimoto Y Hiraga M Hyodo 《Canadian Metallurgical Quarterly》1993,42(6):883-887
We injected botulinum toxin to treat hemifacial spasm, and investigated the effects and the patient's impression of this treatment. Average duration of improvement lasted about 3.5 months in both the initial treatment group and the recurrent group. However the patients in the recurrent group received fewer units of botulinum toxin than those in the initial treatment group. Except for local paralysis that disappeared within a month, there were very few complications. Most patient were satisfied with this treatment. We conclude that the treatment of hemifacial spasm with botulinum toxin is both simple and useful. 相似文献
66.
Chemical and physical synthesis routes were combined to prepare macroporous CaCu(3)Ti(4)O(12) thin films by pulsed laser deposition onto poly(methyl methacrylate) (PMMA) microsphere templated substrates. These films showed remarkably enhanced gas sensitivity compared with control films deposited on untreated substrates, demonstrating the virtues of combining thin film physical vapor deposition (PVD) techniques in concert with colloidal templates to produce macroporous structures of inorganic films with enhanced surface activity for applications in chemical sensors, catalysts, and fuel cells. 相似文献
67.
Tae-Gew Ham Yukio Nakata Rolando Orense Masayuki Hyodo 《Canadian Metallurgical Quarterly》2010,136(5):697-705
In order to investigate the influence of water on compression characteristics of decomposed granite soils, single-particle crushing and one-dimensional compression tests were carried out on three types of decomposed granite soils as well as on quartz-rich silica sand under both dry and wet conditions. Results showed that the initial crushing strength of a single particle was reduced and strength variability increased due to the weakening effects induced by the presence of water. Moreover, it was observed that the one-dimensional compression behavior of decomposed granite soil was related to the initial crushing strength. Finally, the magnitude of initial crushing strength was also affected by the degree of weathering of the soil. 相似文献
68.
In recent years, many cases of alpha-fetoprotein-producing gastric cancer (AFPGC) characterized by increased serum levels of alpha-fetoprotein (AFP) and AFP positivity of the gastric cancer have been reported. Here we present a case of AFPGC coexistent with a different histological type of gastric cancer: The AFPGC was Borrmann type 1 advanced gastric cancer with multiple liver metastasis and appeared to produce both AFP and des-gamma-carboxy prothrombin (PIVKA-II). The second cancer was IIc type early gastric cancer and did not produce AFP. Despite receiving palliative chemotherapy, the patient died, due to hepatic failure, 45 days after admission. 相似文献
69.
70.
Kengo Nojima Kengo Ogata Motomu Tanaka Ryosuke Nishi Yuichi Ono Takao Koide 《Journal of Mechanical Science and Technology》2017,31(12):5657-5663
Case-carburizing enlarges the depth of the hardened layer at the tooth width end on the acute angle side of helical gears. For the helical gears with large helix angles (Exceeding 25°), this hardened layer may lower their bending fatigue strength. Therefore, we investigated the influence of this hardened layer on their bending fatigue strength through the bending fatigue tests. Our results suggest that this hardened layer might reduce the case-carburizing’s effect to enhance their bending fatigue strength. Thus, using only the maximum tooth root stress would be inadequate for evaluating their bending fatigue strength, and it would be necessary to consider the relationship between the hardened layer and the tooth root stress distribution (Especially, the stress applied at the tooth width end on the acute angle side) from the beginning of meshing to the end. 相似文献