全文获取类型
收费全文 | 434篇 |
免费 | 4篇 |
专业分类
化学工业 | 26篇 |
金属工艺 | 31篇 |
机械仪表 | 26篇 |
建筑科学 | 1篇 |
矿业工程 | 3篇 |
轻工业 | 4篇 |
石油天然气 | 8篇 |
无线电 | 2篇 |
一般工业技术 | 25篇 |
冶金工业 | 296篇 |
原子能技术 | 13篇 |
自动化技术 | 3篇 |
出版年
2022年 | 2篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2017年 | 4篇 |
2014年 | 4篇 |
2012年 | 5篇 |
2011年 | 7篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 74篇 |
1997年 | 52篇 |
1996年 | 34篇 |
1995年 | 19篇 |
1994年 | 21篇 |
1993年 | 10篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 8篇 |
1977年 | 28篇 |
1976年 | 47篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 6篇 |
1972年 | 2篇 |
1970年 | 3篇 |
1969年 | 4篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1965年 | 2篇 |
1962年 | 2篇 |
1960年 | 1篇 |
排序方式: 共有438条查询结果,搜索用时 15 毫秒
41.
N. N. Bakhman G. P. Kuznetsov V. M. Puchkov 《Combustion, Explosion, and Shock Waves》2002,38(5):518-524
The mechanisms of propagation of smoldering waves in porous layers of pine sawdust were studied experimentally for cocurrent and opposed airflows in closed (with one open butt–end) and semiclosed (with a flat free surface) systems. We investigated the shape of the smoldering front and the effects of the airflow direction and velocity, combustible-layer porosity, and the dispersity of the sawdust layer on the smoldering wave velocity. Maximum temperature in the smoldering wave is established. In a closed system with airflow velocity higher than 5–7 cm/sec, the smoldering rate is an order of magnitude higher in a cocurrent flow than in an opposed flow. For cocurrent flow, the velocity of a smoldering wave is two orders of magnitude higher in a closed system than in a semiclosed system. The experimental dependences are explained. Key words: smoldering, wave processes, porosity. 相似文献
42.
43.
44.
Melanotic neuroectodermal tumor of infancy (MNTI) is a rare but well-documented lesion of neuroectodermal derivation. Maturation of the neural elements has been reported only occasionally. We report a case of MNTI of the maxilla showing maturation of neural elements to ganglionic cells. 相似文献
45.
46.
This study investigated the therapeutic effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) on a mouse leukemia model. By using a retroviral vector, mouse GM-CSF cDNA was transduced into a highly tumorigenic T leukemia cell line, RL male 1. Injection of GM-CSF-secreting RL male 1 cells into syngeneic BALB/c mice elicited protective immunity in the animals, which could regress preestablished tumors introduced either by a subcutaneous or in an intravenous route. However, the therapeutic effects were less prominent in the mice inoculated with a large tumor load or in mice treated later. Winn tests further demonstrated that the splenocytes from the late-treated group conferred poorer protective effects in terms of reducing the growth of parental RL male 1 cells in naive mice than the splenocytes from the early-treated group. Nonetheless, upon stimulation in vitro, the activity of tumor-specific cytotoxic T lymphocytes (CTL) was comparable in the splenocytes of both groups of mice. Histological analysis also indicated that the CD8+ T cells appeared as early as 3 days following vaccination at the vaccine sites and at the tumor sites in both groups of mice. Above observations implied that the T cells in the animals bearing large tumors appeared to be in a state of suppression or anergy. Systematic histological analyses for 2 weeks provided further insight into various infiltrates at the vaccine sites and at the tumor sites in response to the inoculation of GM-CSF-secreting tumor vaccine. 相似文献
47.
Under analysis are specific features of the clinical course and treatment of infectious complications of the abdominal wall wounds in 209 patients after destructive forms of appendicitis. The microflora of the purulent wound contained gram-negative bacteria in combination with anaerobic nonclostridial flora. The electrochemically activated solution of potassium chloride EHAR-anolit and the endoscopic method were used in complex treatment of the purulent wounds. The recommended method of treatment makes the period of healing the wounds shorter and improves the results of treatment. 相似文献
48.
49.
50.
VK Mazurik VF Mikha?lov LN Ushenkova NA Vodolazskaia NF Raeva GA Chernov TG Shliakova MV Borovkov 《Canadian Metallurgical Quarterly》1997,37(2):165-174
The DNA and RNA contents, RNA/DNA ratio, and spontaneous and latex-induced oxidant activity indices of the whole blood were studied in the nitroblue tetrazolium test of mono- and polymorphonuclear blood leucocytes of intact dogs after injection of lipopolysaccharide pyrogenal. Significant changes in the above parameters were revealed for radioresistant (survived) and radiosensitive (lost) animals exposed to a subsequent prolonged gamma irradiation with a lethal dose of 7.64 Gy (LD75/45). Peroral introduction of 30 mg/kg indometofen (an indole analog of tamoxifen), which is a potential radioprotector, to dogs increased the survival rates of the irradiated dogs up to 93% and aided in the adaptive biochemical changes in the nuclear cell compartment of blood to induce a radioresistant status of the organism. 相似文献