全文获取类型
收费全文 | 355篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 43篇 |
化学工业 | 49篇 |
金属工艺 | 7篇 |
机械仪表 | 12篇 |
建筑科学 | 6篇 |
能源动力 | 8篇 |
轻工业 | 13篇 |
无线电 | 47篇 |
一般工业技术 | 87篇 |
冶金工业 | 68篇 |
原子能技术 | 11篇 |
自动化技术 | 14篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 4篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 10篇 |
2011年 | 12篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 18篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 15篇 |
2004年 | 9篇 |
2003年 | 11篇 |
2002年 | 11篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 15篇 |
1998年 | 30篇 |
1997年 | 20篇 |
1996年 | 19篇 |
1995年 | 8篇 |
1994年 | 10篇 |
1993年 | 11篇 |
1992年 | 8篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有365条查询结果,搜索用时 15 毫秒
31.
The concentrations of quenched-in vacancies retained in B2 intermetallic compound Fe1-cAlc were obtained as functions of composition (0.39 < c < 0.51) and quenching temperature (773–1273 K) from lattice constant and density measurements. Obtained vacancy concentration indicates rather gradual increase with composition in lower Al content region, while it increased rapidly as the composition approaches to stoichiometric composition. Further, the data for slow-cooled (1 K min−1) samples showed that retained vacancy concentration is higher than that for samples annealed at and quenched from 773 K. Observed lattice constant for each composition decreases linearly with vacancy concentration, which is interpreted in terms of atomic size effect. From changes in vacancy concentration with quenching temperature, apparent vacancy formation energies were estimated. The relation between vacancy concentration and microhardness was also examined. Present results of dependency of lattice constant on heat treatment condition confirm the hardening effect due to retained vacancy. Further, the proposed linear relation of hardness to the square root of vacancy concentration is supported by the present study. 相似文献
32.
Mineo Nozaki Shengde Zhang Masao Sakane Kaoru Kobayashi 《Engineering Fracture Mechanics》2011,(8):1794-1807
This paper studies the creep–fatigue crack initiation and failure lives of Sn–3.5Ag solder notched specimens focused on the multiaxial strain at the notch root. Push–pull creep–fatigue tests were performed using three circumferential notched specimens using four kinds of creep–fatigue strain waveforms. Multiaxial strains at the notched section were calculated by finite element (FE) analysis under four kinds of creep–fatigue loading. Creep–fatigue damage laws were applied for evaluating the crack initiation and failure lives using the multiaxial strains obtained by the FE analysis. von Mises equivalent strain at the notch root estimated the crack initiation lives with a large scatter as well as the failure lives. Instead, the mean value of von Mises equivalent strain over the cross section of the notch root estimated the crack initiation and failure lives with a small scatter. 相似文献
33.
ID-based public key cryptosystems and ID-based signature systems are proposed. Users can change their key parameters by themselves easily with no help from the centre. There is no threat of user conspiracy.<> 相似文献
34.
Erdheim-Chester disease is a rare and distinctive lipid granulomatosis with characteristic pattern of radiographic changes in bone. The characteristic radiographic finding is an unusual symmetrical sclerosis at the diametaphyseal portions of many long bones. This study demonstrates a case of Erdheim-Chester disease and mainly documents radiographic findings. 相似文献
35.
36.
Estrogens, used widely from hormone replacement therapy to cancer treatment, are themselves carcinogenic, causing uterine and breast cancers. However, the mechanism of their carcinogenic action is still not known. Recently, we found that estrone (E1) and 17beta-estradiol (E2) could be activated by the versatile epoxide-forming oxidant dimethyldioxirane (DMDO), resulting in the inhibition of rat liver nuclear and nucleolar RNA synthesis in a dose-dependent manner in vitro. Since epoxidation is often required for the activation of chemical carcinogens, we proposed that estrogen epoxidation is the underlying mechanism for the initiation of estrogen carcinogenesis (Carcinogenesis 17 (1996) 1957-1961). It is known that initiation requires the binding of a carcinogen to DNA with the formation of DNA adducts. One of the critical tests of our hypothesis is therefore to determine whether E1 and E2 after activation are able to bind DNA. This paper reports that after DMDO activation, [3H]E1 and [3H]E2 were able to bind to both A-T and G-C containing DNAs. Furthermore. the formation of E1-DNA and E2-DNA adducts was detected by 32P-postlabeling analysis. 相似文献
37.
S Murata A Kobayashi T Takeuchi H Nakajima A Yoshida Y Kurosawa S Miki T Mizoguchi T Sakurai A Kawatani 《Canadian Metallurgical Quarterly》1996,65(3):109-119
Argatroban has selective antithrombin activity and widely used for treatment of ASO. In this study we investigated vasodilating activity of Argatroban besides antithrombin activity in ASO patients. Three patients who have undergone F-P bypasses previously which were all occluded received 10 mg or 20 mg of Argatroban per day intravenously for 4 weeks. Skin temperature were measured before and after administration of Argatroban at the point of 1, 2, 4 weeks which increased 2.3-6.0 degrees C after administration of Argatroban. Subjective symptoms were also improved and these patients became to be able to walk 1.5-3.3 km. These patients were also given PGE, intravenously, however, temperature increase was less than 1.1 degrees C. These results showed that Argatroban has not only antithrombin activity but also significant vasodilating activity resulting in increase of skeletal muscle blood flow. 相似文献
38.
A black-matrix-type electroosmotic display (EOD) device is described. It makes use of a transparent porous substance with fine dot-shaped depressions on its surface and whose pores are filled with a transparent liquid with a high electroosmotic mobility. The device is manufactured using an embossing process and conventional printing techniques. The principle of operation involves electroosmotic movement to control the wetting of the depression's sloped surfaces on the porous substance. Characteristics of the EOD device are presented and a multicolor experimental numerical display is described. The EOD device has a relatively fast response time and low power consumption (less than 102 μW/cm2) 相似文献
39.
Presents a cryptographically secure pseudorandom sequence generator where two prime numbers are arbitrary, based on the public key cryptosystem proposed by one of the authors 相似文献
40.
K Kurosawa K Miyazawa A Gotoh T Katagiri J Nishimaki LK Ashman K Toyama 《Canadian Metallurgical Quarterly》1996,87(6):2235-2243
Interaction of a tyrosine kinase type receptor and its ligand induces receptor-dimerization or -oligomerization followed by transphosphorylation and activation of its intrinsic kinase, which leads to a series of intracellular signals. We have previously reported that the membrane-bound form of Steel factor (SLF) induces more persistent tyrosine kinase activation and longer life span of c-kit encoded protein (KIT) than its soluble form (Miyazawa et al, Blood 85:641, 1995). In this study, we used YB5.B8 monoclonal antibody (MoAb) that recognizes the extracellular domain of KIT to investigate whether immobilized anti-KIT MoAb can substitute for SLF as a potent activator of KIT by cross-linking receptors and further compared its effect with each SLF isoform in a factor-dependent cell line M07e. YB5.B8 MoAb in a soluble state suppressed SLF-induced M07e cell proliferation in a dose-dependent manner. By contrast, once this antibody was immobilized on the goat-antimouse MoAb (GAM)-coated culture plates, it supported the growth of M07e cells in the absence of any growth factors, whereas culture the cells in GAM alone or YB5.B8 without GAM-coated plates resulted in rapid cell-death within 24 hours. As with the natural ligand SLF, immobilized YB5.B8 MoAb synergized with granulocyte-macrophage colony-stimulating factor (GM-CSF) in inducing cell proliferation compared with either YB5.B8 MoAb or GM-CSF alone. Immunoblotting with antiphosphotyrosine MoAb showed that interaction of M07e cells with immobilized YB5.B8 induced tyrosine phosphorylation of a series of intracellular proteins including KIT (145 kD). In addition, cross-linking studies using a water-soluble cross linking reagent bis-sulfosuccinimidyl-suberate showed that immobilized YB5.B8 MoAb induced dimerization and activation of KIT. However, as with stimulation by the membrane-bound form of SLF, the kinetics of KIT activation with YB5.B8 MoAb was more prolonged compared with the cells treated with recombinant soluble SLF. Flow cytometry showed that, unlike the cells treated with soluble SLF, no downmodulation of cell-surface KIT expression was observed in M07e cells cultured with immobilzed YB5.B8 MoAb. These data suggest that immobilized antibodies against hematopoietic receptors may replace their ligand-stimulators; however, their activities may resemble the membrane-bound form rather than the soluble form of natural ligands. 相似文献