全文获取类型
收费全文 | 224983篇 |
免费 | 15089篇 |
国内免费 | 53篇 |
专业分类
240125篇 |
出版年
2021年 | 1799篇 |
2018年 | 3149篇 |
2017年 | 3040篇 |
2016年 | 3702篇 |
2015年 | 3238篇 |
2014年 | 4485篇 |
2013年 | 6385篇 |
2012年 | 7657篇 |
2011年 | 8148篇 |
2010年 | 5771篇 |
2009年 | 4922篇 |
2008年 | 7271篇 |
2007年 | 7556篇 |
2006年 | 7232篇 |
2005年 | 6771篇 |
2004年 | 6915篇 |
2003年 | 6614篇 |
2002年 | 6565篇 |
2001年 | 9278篇 |
2000年 | 8956篇 |
1999年 | 6993篇 |
1998年 | 2134篇 |
1997年 | 1963篇 |
1996年 | 1825篇 |
1992年 | 5471篇 |
1991年 | 5679篇 |
1990年 | 5652篇 |
1989年 | 5620篇 |
1988年 | 5213篇 |
1987年 | 4866篇 |
1986年 | 4443篇 |
1985年 | 4677篇 |
1984年 | 3699篇 |
1983年 | 3030篇 |
1982年 | 2017篇 |
1981年 | 1724篇 |
1980年 | 1728篇 |
1979年 | 3340篇 |
1978年 | 2577篇 |
1977年 | 2375篇 |
1976年 | 2331篇 |
1975年 | 2827篇 |
1974年 | 3119篇 |
1973年 | 3084篇 |
1972年 | 2746篇 |
1971年 | 2604篇 |
1970年 | 2212篇 |
1969年 | 2158篇 |
1968年 | 2032篇 |
1967年 | 1797篇 |
排序方式: 共有10000条查询结果,搜索用时 4 毫秒
961.
962.
963.
V M Man'ko N A Khalat'ian T B Rudneva 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1978,(11):81-85
Antisera to membrane antigens of B lumphocytes eliminated the capacity of lymphocytes to inactivate allogenous stem cells by 60%; however, lymphocytes from the lymph nodes of B mice possessed no inactivating capacity. T-lymphocytes were the main criteria inactivating allogenous stem cells. Cooperating with T-lymphocytes, B-lymphocytes probably contributed to inactivation of precursor cells realized by T-lymphocytes. However, the presence of B-lymphocytes in the killer cells population was not a determinant, since T-lymphocytes were capable of inactivating allogenous stem cells without any participation of B-lymphocytes. 相似文献
964.
It was found that interaction of 1O2 with bacterial membranes of E. coli cells results in covalent binding and aggregation of membrane proteins. This process was shown to be inhibited by water-soluble free radical scavengers, e. g., 1O2 quenchers (cysteine, sodium azide, histidine), of which the latter afforded the strongest inhibition. No protective effect of the fat-soluble free radical scavenger ionol (BHT) on membrane protein aggregation was observed. It was assumed that the main role in oxidative destruction of bacterial membranes (in contrast to membranes from animal sources) is ascribed to processes which are not coupled to lipid peroxidation. 相似文献
965.
966.
A N Klimov A A Nikiforova V T Lozovski? A M Chistiakova E Ia Magracheva 《Biokhimii?a (Moscow, Russia)》1978,43(9):1721-1722
A new subclass of high density lipoproteins designated as HLD2c was found in the human blood plasma of newborn by analytic ultracentrifugation in the flotation rate interval Fo1,20 8.0--12.0. HDL2c was isolated from the total HDL fraction of newborn by preparative ultracentrifugation at the density 1.071. 相似文献
967.
After a short irradiation at 366 nm with 200 lx, the intensity of conidiation ofTrichoderma viride colonies grown in the dark increased for the first 10 s proportionally with time. The increase slowed down after 10 s—6 min
of exposure and after 10–60 min of irradiation the conidiation intensity began to decrease. When photo-induced by daylight,
the conidiation started at a high rate after 25 h and persisted even after 48 h. The conidiation had no circadian character
and its periodicity depended on the periodicity of photo-induction. Its intensity was also influenced by the carbon sources
used, a maximum being reached with glucose (1–2 %). Higher glucose concentrations inhibited conidiation but had no influence
on growth of colonies. 相似文献
968.
M S Ba?zhomartov S V Prozorovski? V I Vasil'eva I I Efremova M A Furman 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1979,(5):83-87
A complex of immunological cell tests with M. pneumoniae antigen (the lymphocyte blast-cell transformation test, the allergic neutrophil alteration test) was carried out in order to establish the correlation between the results of positive seroconversion and the sepcific immunological reactivity of lymphoid cells in pneumonia patients. Mycoplasmic cutireactive allergen, when used for the accelerated diagnosis of mycoplasmic pneumonia in humans, was shown to be specific and safe. Cuti-allergic tests with mycoplasmic allergen allowed to diagnose mycoplasmic pneumonia at early stages (beginning from days 5--7), which ensures the possibility of indicating etiotropic treatment to patients in due time. 相似文献
969.
970.
Experiments were conducted on mature female rats. Simultaneous administration through a tube for 14 days, daily, of mestranol (0.04 mg/kg) and megestrol acetate (0.8 mg/kg) gave no significant contraceptive effect, whereas the use of steroid preparations in the same doses in combination with antiadrenergic substances--dopegit (100 mg/kg) or pyrroxan (10 mg/kg) prevented pregnancy effectively. 相似文献