全文获取类型
收费全文 | 1267篇 |
免费 | 1篇 |
专业分类
化学工业 | 3篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
轻工业 | 15篇 |
水利工程 | 1篇 |
一般工业技术 | 2篇 |
冶金工业 | 1241篇 |
自动化技术 | 2篇 |
出版年
2021年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 46篇 |
1998年 | 395篇 |
1997年 | 203篇 |
1996年 | 152篇 |
1995年 | 66篇 |
1994年 | 48篇 |
1993年 | 61篇 |
1992年 | 11篇 |
1991年 | 15篇 |
1990年 | 10篇 |
1989年 | 15篇 |
1988年 | 16篇 |
1987年 | 12篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1978年 | 5篇 |
1977年 | 35篇 |
1976年 | 111篇 |
1975年 | 2篇 |
1955年 | 2篇 |
排序方式: 共有1268条查询结果,搜索用时 9 毫秒
61.
62.
63.
64.
65.
66.
ES Aka?zin 《Canadian Metallurgical Quarterly》1998,(5):22-25
The autolysis of Escherichia and Salmonella, depending on the conditions of the medium where the cultivation and lysis of the bacteria took place, was studied. The study revealed that the autolysis of these bacteria was most intensive if lysis was induced at the moment when the culture achieved the maximum specific growth rate, as well as in case when the extreme conditions were maintained in the medium during the autolytic process. Approaches to controlling the process of the induced autolysis of Escherichia and Salmonella were proposed and substantiated. 相似文献
67.
68.
69.
This paper presents the results of a study on the introduced, free-ranging patas monkey population of Southwestern Puerto Rico (SWPR). It describes information on the population size, social group composition, diet, daily ranging patterns, and patas home range during a 3 year period. The patas monkey population in the study area consisted of approximately 120 individuals in four heterosexual groups and several all-male bands. Within their home ranges (26.8 km2), the population density was 4.47 individuals/km2. Home range size among the population's four heterosexual groups varied from 3.72 km2 to 15.39 km2, and minimum daily distance traveled ranged from 0.8-2.0 km. In general, the social structure and mating system of this population parallels what has been described for African populations. However, habitat use, ranging behavior, and the quality of intergroup interactions suggests that patas of this population exhibit territorial behavior. 相似文献
70.