全文获取类型
收费全文 | 479篇 |
免费 | 8篇 |
专业分类
电工技术 | 19篇 |
化学工业 | 76篇 |
金属工艺 | 7篇 |
机械仪表 | 11篇 |
建筑科学 | 5篇 |
能源动力 | 6篇 |
轻工业 | 27篇 |
无线电 | 90篇 |
一般工业技术 | 61篇 |
冶金工业 | 155篇 |
原子能技术 | 15篇 |
自动化技术 | 15篇 |
出版年
2022年 | 8篇 |
2021年 | 7篇 |
2020年 | 1篇 |
2019年 | 7篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 6篇 |
2014年 | 7篇 |
2013年 | 24篇 |
2012年 | 11篇 |
2011年 | 21篇 |
2010年 | 9篇 |
2009年 | 10篇 |
2008年 | 14篇 |
2007年 | 12篇 |
2006年 | 14篇 |
2005年 | 12篇 |
2004年 | 14篇 |
2003年 | 17篇 |
2002年 | 13篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 12篇 |
1998年 | 59篇 |
1997年 | 40篇 |
1996年 | 20篇 |
1995年 | 9篇 |
1994年 | 18篇 |
1993年 | 18篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 11篇 |
1989年 | 14篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有487条查询结果,搜索用时 15 毫秒
71.
Kashii M Fujisawa R Adachi H Mori Y Sasaki T Koga Y Takano K Kanaya S Matsumura H Inoue T Murakami S Sugamoto K Yoshikawa H 《Journal of Bioscience and Bioengineering》2006,102(4):372-374
We developed a novel technique for detaching protein crystals from glass capillary tube using the counter diffusion crystallization technique by femtosecond laser irradiation. X-ray diffraction analysis demonstrated that femtosecond laser irradiation has little effect on crystallinity. This technique will contribute to progress in structural genomics as a powerful tool. 相似文献
72.
Kouki Ishii Yoshihiro Mizutani Yoshiro Suzuki Yoichiro Koga Ryosuke Matsuzaki 《Advanced Composite Materials》2019,28(4):383-395
Three-dimensional (3D) printing is an attractive technology to produce complex structures without the need for expensive tools and molds. Additives are usually incorporated with the plastic materials used in 3D printing to increase their strength and rigidity. In particular, carbon fiber-reinforced plastic (CFRP) shows promise as a material for use in 3D printing. However, the strength of CFRP after printing is still unclear, although it is known that its strength is affected by the plastic melting during printing. In this study, we analyzed the fracture behavior of CFRP specimens before and after bending to different curvature radii. From the experimental results, a fracture criterion that described the behavior of the materials by considering tensile and compressive loads was developed. The fracture mechanism was the same for CFRP specimens with different curvature radii. These results increase our understanding of the mechanical properties of CFRP materials used in 3D printing. 相似文献
73.
The attachment of peptides to the surface of spherical dendrimers via graft polymerization is described here (see Figure). It is shown that the resulting peptide dendrimers display greatly enhanced helicity compared to non‐dendrimer‐based analogues. This effect is attributed to aggregation of peptide segments on the dendrimer surface. 相似文献
74.
Maeda Yoshitake; Koga Hiroshi; Yamada Hidenori; Ueda Tadashi; Imoto Taiji 《Protein engineering, design & selection : PEDS》1995,8(2):201-205
To increase the folding yield of concentrated reduced lysozyme,we developed a renaturation method by means of dialysis fromconcentrated urea with redox agents. After lysozyme was incubatedin the reducing buffer (8 M urea solution) with oxidized glutathione,renaturation of reduced lysozyme was started by dialysis againstthe dialyzing buffer containing 8 M urea with redox agents.The urea concentration of the dialyzing bottle was graduallydiluted with dialyzing buffer without urea at a flow rate of0.1 ml/min by high pressure pump. Using this systematic dialysis,a concentration as high as 5 mg/ml of reduced lysozyme couldbe renaturated in 80% yield, while the folding yield was <5%even at a concentration of 1 mg/ml using a conventional rapiddilution method [Goldberg et al. (1991) Biochemistry, 30, 27902797].Therefore, it was concluded that gentle removal of urea fromdenatured proteins, dissolved in concentrated urea solution,by means of dialysis should be useful to renature denaturedproteins effectively. 相似文献
75.
Warm deep drawing of wrought magnesium alloy sheets produced by semi-solid roll strip-casting process 总被引:1,自引:0,他引:1
H. Watari N. Koga K. Davey T. Haga M.T. Alonso Ragado 《International Journal of Machine Tools and Manufacture》2006,46(11):1233-1237
This paper is concerned with the development of a continuous strip-casting technology to facilitate the manufacture of magnesium sheet alloys economically whilst maintaining high quality. Established in the paper is warm formability of cast magnesium alloy sheets after being hot rolled by semi-solid roll strip-casting process. It has been found that magnesium sheet with 2.0–4.0 mm thickness could be produced at a speed of 25 m/min. Hot rolling and annealing temperatures during hot rolling were also changed to examine which condition would be appropriate for producing wrought magnesium alloys with good formability. Microstructures of the crystals of the manufactured wrought magnesium alloys were observed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep-drawing test of the cast magnesium alloy sheets after being hot rolled. 相似文献
76.
Yoshio Maruyama Yoichiro Iwase Kazuo Koga Junichi Yagi Hiroo Takada Naohisa Sunaga Shigeomi Nishigaki Takashi Ito Kinya Tamaki 《Automation in Construction》2000,9(5-6):503-514
In this study, we proposed a concept of virtual and real-field construction management systems (VR-Coms), which is integrated with virtual construction simulation, planning, scheduling, and performance management systems to evaluate productivity and safety in virtual simulated and real-field constructions. And, we built up a computational environment to develop the VR-Coms. The VR-Coms offer supporting modules for learning and discovering solutions with objective to manage construction at right speed with improved humanware and constructability. The configuration of VR-Coms is described. This paper also shows an application of agent theory to construction management. 相似文献
77.
78.
Y Sugimoto T Kusakabe S Nagaoka T Nirasawa K Tatsuguchi M Fujii T Aoki K Koga 《Canadian Metallurgical Quarterly》1996,1295(1):96-102
Visual presentation of an object produces firing patterns in cell assemblies representing the features of the object. Based on theoretical considerations and animal experiments, it has been suggested that the binding of neuronal representations of the various features is achieved through synchronization of the oscillatory firing patterns. The present study demonstrates that stimulus-induced gamma-band responses can be recorded non-invasively from human subjects attending to a single moving bar. This finding indicates the synchronization of oscillatory activity in a large group of cortical neurons. Gamma-band responses were not as apparent in the presence of two independently moving stimuli, suggesting that the neuronal activity patterns of different objects are not synchronized. These results open a new paradigm for investigating the mechanisms of feature binding and association building in relation to subjective perception. 相似文献
79.
T Obata F Shishido M Koga H Ikehira F Kimura K Yoshida 《Canadian Metallurgical Quarterly》1996,14(10):1143-1148
The development of phase-contrast magnetic resonance imaging (P-C MRI) provides a noninvasive method for measurement of volumetric blood flow (VFR). We performed P-C MRI to study the effects of physical characteristics on cerebral blood flow. VFR of the left and right internal carotid arteries and basilar artery were measured using P-C MRI and total cerebral blood flow (tCBF) was calculated by summing up the VFR values in the three vessels. Moreover, we investigated the changes in these blood flows as influenced by age, head size, height, weight, body surface area, and handedness. The blood flows were 142 +/- 58 ml/min (mean +/- standard deviation) in the basilar artery; and 229 +/- 86 ml/min in the left, and 223 +/- 58 ml/min in the right internal carotid artery; and tCBF was 617 +/- 128 ml/min. Significant increases were observed in head size-related change of VFR in the basilar artery (p = .028) and height-related change of tCBF (p = .045). The other characteristics did not significantly influence any VFR. The results suggest that head size and height may reflect CBF, and that these effects should be considered when changes of CBF are diagnosed. Phase-contrast MRI is useful for a noninvasive and rapid analysis of cerebral VFR and has potential for clinical use. 相似文献
80.
H Koga K Hayashi E Taketomi S Matsunaga S Yashiki T Fujiyoshi S Sonoda T Sakou 《Canadian Metallurgical Quarterly》1996,21(4):469-473
STUDY DESIGN: The present study analyzed the restriction fragment length polymorphism patterns of alpha 2(XI) collagen, bone morphogenetic protein-2, alkaline phosphatase, and tumor necrosis factor-alpha genes in patients with ossification of the posterior longitudinal ligament. This study investigates the genetic polymorphism of bone-induced factors in patients with ossification of the posterior longitudinal ligament and compares it with healthy control subjects. OBJECTIVES: To clarify the genetic markers linked to ossification of the posterior longitudinal ligament. SUMMARY OF BACKGROUND DATA: Ossification of the posterior longitudinal ligament is a genetic disease associated with abnormal calcium metabolism involving the posterior longitudinal ligament. Previous genetic studies have not identified the pathologic mechanism of ossification of the posterior longitudinal ligament. Histopathologic studies of ossification of the posterior longitudinal ligament and the animal model, the spinal hyperostotic mouse, have revealed an increase in Type XI collagen and bone morphogenetic protein-2 expression. METHODS: Eighteen Japanese patients with ossification of the posterior longitudinal ligament and 51 healthy, unrelated control subjects were investigated for the restriction fragment length polymorphism patterns of COL11A2, bone morphogenetic protein-2, alkaline phosphatase, and tumor necrosis factor-alpha, genes with various restriction endonucleases. RESULTS: The gene frequencies of COL11A2 obtained with BamHl (10.0 kb fragment) and HindIII (19.0 kb fragment) observed in patients with ossification of the posterior longitudinal ligament were higher compared with control subjects (0.43 and 0.14, respectively). These differences were statistically significant (BamHl P = 0.018; Hindlll P = 0.046). Two new restriction fragment length polymorphism patterns were detected of the bone morphogenetic protein-2 gene with Mspl and Taql and one already known restriction fragment length polymorphism pattern of the tumor necrosis factor-alpha gene with Ncol. However, they were not significantly different from the control subjects. CONCLUSIONS: Seven restriction fragment length polymorphisms of COL11A2 gene were identified. Two of them (BamHl, 10.0/10.0 kb genotype; HindIII, 19.0/19.0 kb genotype) were significantly different in patients with ossification of the posterior longitudinal ligament. 相似文献