全文获取类型
收费全文 | 5611篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 37篇 |
机械仪表 | 8篇 |
建筑科学 | 5篇 |
能源动力 | 5篇 |
轻工业 | 21篇 |
水利工程 | 4篇 |
无线电 | 42篇 |
一般工业技术 | 43篇 |
冶金工业 | 5434篇 |
原子能技术 | 1篇 |
自动化技术 | 12篇 |
出版年
2023年 | 2篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2014年 | 3篇 |
2013年 | 12篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 5篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 8篇 |
2003年 | 15篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 165篇 |
1998年 | 1661篇 |
1997年 | 904篇 |
1996年 | 642篇 |
1995年 | 328篇 |
1994年 | 314篇 |
1993年 | 333篇 |
1992年 | 39篇 |
1991年 | 58篇 |
1990年 | 86篇 |
1989年 | 67篇 |
1988年 | 67篇 |
1987年 | 85篇 |
1986年 | 63篇 |
1985年 | 58篇 |
1984年 | 3篇 |
1983年 | 13篇 |
1982年 | 34篇 |
1981年 | 35篇 |
1980年 | 40篇 |
1979年 | 1篇 |
1978年 | 10篇 |
1977年 | 143篇 |
1976年 | 337篇 |
1975年 | 13篇 |
1974年 | 1篇 |
1971年 | 2篇 |
1968年 | 2篇 |
1965年 | 1篇 |
1955年 | 5篇 |
排序方式: 共有5612条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
A memory-based processing approach to discourse comprehension emphasizes the rapid deployment of information in memory to facilitate understanding of the text that is currently being read. S. B. Greene, R. J. Gerrig, G. McKoon, and R. Ratcliff (1994) demonstrated that when a text described the reunion of 2 characters who had previously discussed a 3rd character, the accessibility of the 3rd character increased, and the use of an unheralded pronoun (R. J. Gerrig, 1986) to refer to that character was felicitous. In experiments in this article, the authors demonstrate that concepts related to the unheralded pronoun also increase in accessibility and that those concepts form associations in memory with concepts present in the discourse at the time the pronoun is used. The authors also show that the increase in accessibility for the referent of the pronoun, as well as the appropriate long-term memory associations, occurs even in the absence of the pronoun. 相似文献
5.
6.
7.
A Castellanos F Moleiro A Interian RJ Myerburg 《Canadian Metallurgical Quarterly》1995,107(5):1463-1464
Until recently, it had not been recognized that predictions regarding the number of sinus beats interposed between two consecutive parasystolic beats could be made. In a case of perfect, pure parasystole resulting from unintentional fixed rate ventricular pacing, the following was observed: there were consistently three different values (0,2,3) for the number of interposed sinus beats; only one of these values was odd, and the sum of the two smaller values was one less than the larger value. Our findings, which are in keeping with those obtained in an mathematical model, may be of additional help in the diagnosis of this elusive arrhythmia. 相似文献
8.
9.
J Booij RJ Knol L Reneman K de Bruin AG Janssen EA van Royen 《Canadian Metallurgical Quarterly》1998,25(12):1666-1669
Flavobacterium aurantiacum NRRL B-184 possesses the ability to degrade aflatoxin B1 in solution and in several food items. Aflatoxin B1 is a potent carcinogen that causes significant economic losses to the agricultural and food industry. The role of trace metal ions (Cu2+, Mn2+, Zn2+, and Co2+) were studied in an effort to understand the enzymatic system involved in aflatoxin B1 degradation by F aurantiacum. The effect of divalent chelators (EDTA and 1,10-phenanthroline [OPT]) in the presence of the trace metal ions was studied as well. Aflatoxin B1 (10 microg/ml) was added to 72-h cultures of F aurantiacum that had been washed and resuspended in phosphate buffer (pH 7.0). HPLC was used to determine aflatoxin B1 concentration in these cultures. Incubating cells at 30 degrees C with 1 and 10 mM Cu2+, Mn2+, and Zn2+ significantly decreased aflatoxin B degradation after 4 and 24 h (P < 0.05). Decreased degradation was also observed with 1 and 10 mM Cu2+ and Zn2+ after 48 h and with 0.1 mM Cu2+ after 24 and 48 h. Co2+ did not have a significant effect on aflatoxin B1 degradation. EDTA and OPT did not counter the inhibition in the presence of Cu2+. The addition of 1 mM EDTA countered the inhibition by 1 mM Mn2+ after 4 and 24 h, but 1 mM OPT did not counter the inhibition by 10 mM Mn2+ after 4 and 24 h. OPT countered the inhibition by 1 mM Zn2+ after 4 and 48 h. These trace elements inhibit aflatoxin B1 degradation by F aurantiacum. In addition, their presence necessitates higher concentrations (>1 mM) of EDTA and OPT for the removal of their inhibitory effect. 相似文献
10.