全文获取类型
收费全文 | 3054篇 |
免费 | 1篇 |
专业分类
综合类 | 1篇 |
化学工业 | 9篇 |
机械仪表 | 1篇 |
建筑科学 | 1篇 |
轻工业 | 1篇 |
一般工业技术 | 3篇 |
冶金工业 | 3035篇 |
自动化技术 | 4篇 |
出版年
2016年 | 1篇 |
2012年 | 1篇 |
2010年 | 2篇 |
2007年 | 1篇 |
2005年 | 3篇 |
2003年 | 5篇 |
1999年 | 105篇 |
1998年 | 946篇 |
1997年 | 551篇 |
1996年 | 332篇 |
1995年 | 197篇 |
1994年 | 156篇 |
1993年 | 173篇 |
1992年 | 17篇 |
1991年 | 45篇 |
1990年 | 34篇 |
1989年 | 42篇 |
1988年 | 55篇 |
1987年 | 45篇 |
1986年 | 30篇 |
1985年 | 21篇 |
1983年 | 5篇 |
1982年 | 14篇 |
1981年 | 14篇 |
1980年 | 27篇 |
1979年 | 3篇 |
1978年 | 11篇 |
1977年 | 66篇 |
1976年 | 151篇 |
1975年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有3055条查询结果,搜索用时 453 毫秒
941.
EK Balashova DL Pevzner VI Rozengart OE Sherstobitov AA Abduvarkhabov 《Canadian Metallurgical Quarterly》1976,48(4):460-464
Hydrophobity (coefficient in distribution in the hexane water system) and the content of cholinesterase organophosphorous inhibitors (OPI) of the structure Ro (CH3) P (O) SC2H4 SC2H5 were studied in the rat brain. When the O-alkyl radical is increased hydrophobity rises and the relative content of free OPI in the brain extracted by chloroform decreases. With an increase in R from the ethyl to butyl one the ability to the additional inhibition of the brain own cholinesterase lowers due to incubation of homogenate at 37 degrees C, that evidences for an essential drop in the studied series of the free OPI fraction relative to the free OPI extracted by chloroform. 相似文献
942.
DL Wassom DA Loegering GO Solley SB Moore RT Schooley AS Fauci GJ Gleich 《Canadian Metallurgical Quarterly》1981,67(3):651-661
A radioimmunoassay was established for the human eosinophil granule major basic protein (MBP). The mean level of MBP in sera from 105 normal control patients was 454 ng/ml, whereas in a sample of 188 patients with various forms of diseases, including the hypereosinophilic syndrome, levels as high as 14,000 ng/ml were measured. Serum levels of MBP did not correlate with eosinophil counts in normal subjects, but a positive correlation was seen in patients with eosinophilia; the patients with eosinophil counts greater than 350/mm3 generally showed increased levels of MBP. Many patients with skin disease and normal eosinophil counts had elevated levels of serum MBP. Monomer MBP has a molecular weight of 9,300, but in sera of patients with eosinophilia, the MBP activity was of high molecular weight, greater than 50,000. Analyses of serum by Sephadex G-200 and by electrofocusing suggest that MBP is not simply polymerized, but rather is bound to a larger carrier molecule. Monomeric MBP can be isolated from serum by reduction of serum with dithiothreitol, alkylation with iodoacetamide, and acidification to pH 2 followed by fractionation on Sephadex G-50 at pH 2. Under these conditions, up to 80% of the MBP emerges in monomeric form. The results indicate that eosinophil granule proteins circulate in blood covalently bound to serum proteins, and that elevated concentrations of serum MBP are present in some diseases associated with eosinophilia. 相似文献
943.
944.
945.
946.
947.
948.
The mixed-function oxidase which activates the carcinogen dimethylnitrosamine (DMN) was determined in the rat liver as a function of animal age. DMN-demethylase activity increased considerably at first to reach a maximum on day 29, and then substantially decreased to day 59; thereafter, enzyme activity remained essentially stable up to at least day 110. Pretreatment with 3-methylcholanthrene, which caused a pronounced decrease in this enzyme activity, did not affect the general shape of the age-dependence curve. The results suggest that rats between weaning and sexual maturity are more susceptible to the carcinogenic effects of pulse doses of DMN than are neonates or adult animals. 相似文献
949.
This study describes a clinical intervention program that was used to facilitate development of receptive and expressive language skills in a group of four psychotic children. A group format utilizing an interactive language development teaching procedure combined with a therapeutic milieu was shown to be effective in establishing and expanding communicative behaviors in psychotic children. Nine diagnostic measures were utilized to assess children's performance prior to therapy and at the end of three-month and six-month intervals. Results indicated substantial reduction of delayed and immediate echolalia, jargon, inappropriate stress, pitch, and intonation. Substantial improvement was noted in expressive syntactic and morphological functioning and in the children's ability to generate novel utterances about day-to-day experiences, family, and toys. Increases in children's concept of body image and ego functioning paralleled their improvement in receptive and expressive language development. 相似文献
950.