全文获取类型
收费全文 | 109篇 |
免费 | 2篇 |
国内免费 | 2篇 |
出版年
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2009年 | 4篇 |
2008年 | 6篇 |
2007年 | 3篇 |
2006年 | 1篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1980年 | 5篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1965年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有113条查询结果,搜索用时 78 毫秒
11.
本研究以昆明山海棠根部水抽提物(Tripterygium Hypoglaucum(Level)Hutch,THH)处理中国仓鼠V79细胞,通过检测V79细胞C-M细胞频率以及二酰基甘油(1,2-diacylgcerol,DAG)的含量测定,分析了THH诱发非整倍体与细胞醇磷酯信号通路的关系.结果指出THH能在1mg/ml、2mg/ml两个剂量上使V79细胞的DAG含量显著升高(P<0.001),并明显的提高C-M细胞频率(P<0.05),提示肌醇酯信号通路是介导THH诱发非整倍体的途径之一. 相似文献
12.
Maurine W. Dietz Sijmen van Mourik Øivind Tøien Peter A. Koolmees Monique H. G. Tersteeg-Zijderveld 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1997,167(6):451-460
Turkey (Meleagris gallopavo) and guinea fowl (Numida meleagris) chicks (0–27 days posthatch) were exposed to decreasing or increasing ambient temperatures. Root mean square electromyographic
activity of musculus pectoralis (m. pect.) and musculus iliotibialis (m. iliot.) was recorded simultaneously with O2 consumption and CO2 production. From both muscles, relative mass, water fraction and fibre type were determined. M. iliot. participated in shivering
from hatching onwards. The relationship between its root mean square electromyographic activity and ambient temperature resembled
that of metabolic rate and ambient temperature, and the shivering threshold temperature was indistinguishable from the lower
critical temperature. This suggests that the leg muscles are major contributors to shivering thermogenesis. M. pect. participated
in shivering only at days 6–20 in turkeys and at days 6–10 in guinea fowl. Both water fraction and histological analysis indicated
that m. pect. was less developed than m. iliot. at hatching. We hypothesize that a minimal level of maturity is required before
a muscle can participate in shivering, which is probably represented by a water fraction of about 0.85. Both species recruited
the aerobic leg muscles first; the anaerobic breast muscle was recruited only when the rate of mass-specific heat loss was
high.
Accepted: 20 March 1997 相似文献
13.
14.
多色荧光原位杂交对昆明山海棠和丙烯酰胺诱发微核染色体组成的研究 总被引:2,自引:0,他引:2
采用着丝粒和端粒DNA探针多色荧光原位杂交,分析了昆明山海棠和丙烯酰胺诱导的
NIH3T3细胞微核的染色体组成。结果表明,昆明山海棠和丙烯酰胺诱导的由整条染色体组成的微核分别可达70.7%和65.9%,提示昆明山海棠和丙烯酰胺均有较强的非整倍体毒性。 相似文献
15.
昆明山海棠根部水抽提物对体外微管蛋白聚合的影响 总被引:2,自引:0,他引:2
本研究利用猪脑中分离纯化的微管蛋白聚合和解聚反应,分析了非整倍体诱发剂昆明山海棠根部水抽提物(THH)对微管蛋白聚合状态的影响,从该角度探讨了THH诱发哺乳动物非整倍体的机制。秋水仙素(COL)为本研究的阳性对照物。结果发现THH能显著抑制体外微管蛋白的聚合,该抑制效应呈明显的剂量——效应关系。研究结果与我们以往关于THH为非整倍体诱发剂的实验证据相吻合并进一步提示THH可以抑制微管蛋白聚合作为诱发非整倍体的途径之一。 相似文献
16.
江苏海门王浩钻孔全新世钙质超微化石的环境意义 总被引:1,自引:0,他引:1
初步研究了海门王浩地区WZK010、WZK214、WZK3003钻孔中的全新世钙质超微化石组合,优势种G.oceanica在组合中平均占97%,依据化石的种数,丰度和保存状况,自下而上划分3个亚组合,第I亚组合,深度74-47m,由G.oceanica,H.carterii,H.wallich ii,S.lamina,U.sibogae组成,丰度较高,保存较好,代表前三角洲-浅海环境,第Ⅱ亚组合, 相似文献
17.
Eizi Yano 《Population Ecology》1989,31(1):89-104
Simulation studies were performed to analyze factors affecting the population dynamics of the system with the greenhouse whitefly (Trialeurodes vaporariorumWestwood ) and the parasitoid Encarsia formosaGahan and to develop strategies for the introduction of E. formosa. The reduction of parasitization efficiency with an increase in parasitoid density promotes the stability of the system, which coincides with the prediction from current theory. The stability of the system is also shown to be promoted by the effect of host feeding. The population levels of the system are remarkably suppressed with an increase in searching efficiency and a decrease in host oviposition. The control effect of the parasitoids is enhanced when the number of parasitoids is divided among many introductions. An optimal time, an optimal density ratio of parasitoids to hosts and optimal densities of hosts and parasitoids exist in the introduction programme of parasitoids. 相似文献
18.
Using 5 density levels, the effect of increasing density was studied on several population statistics of adult Delia (=Hylemya) antiqua. Amongst the statistics studied were adult lifespan; female mating frequency, fecundity and egg hatchability. It was shown that females lived significantly longer than males and that increasing density significantly reduced lifespan. Density had no effect on mating frequency. Total fecundity/female was significantly reduced with increasing density but oviposition rate was density independent. Using these statistics, mean generation time T, net reproduction rate R0 and capacity for increase rc were calculated at the different density levels. Values of R0 showed a one-tailed response but there was no clear effect of density on rc. Multiple comparisons between variables revealed several important relationships.
- Adult lifespan was the most important factor affecting egg production.
- Number of mated females was more important in affecting total fecundity/cage than adult density.
19.
Ryo Tanaka 《Population Ecology》1962,4(1):8-16
Summary The vole,Eothenomys smithi, in highlands of Shikoku was studied to disclose ups and downs of adrenal activities under the influence of the breeding
level in natural populations. It has proved that the vole's adrenal in both sexes may be much more strongly by rise and fall
of the fertility as well as by shift of the age structure in populations than the rat's. Therefore, as for perhaps all kinds
of small mammals, we consider necessary to follow a pertinent procedure to avoid thoroughly these sources of error in studies
to draw any conclusion for or against theChristian's theory. The present data analysed by such a method failed to afford any confirmative proofs; the fact that the pregnancy
rate was increased in parallell to the density is against his view. However, never the whole content of the theory has been
invalidated by these results. 相似文献
20.
AsMatsumoto andHuffaker (1973) concluded that their initial universe size was too small for the proper separation of the effects of host density and dispersion on parasite performance, a larger universe of 38 1/2″ (length) ×38 1/2″ (width) ×3″ (height) was used. When individual parasites were exposed to fixed densities and dispersion patterns of host, they displayed an overall decrease in the parasitization rate when compared to the small universe. In all cases aHolling -type response resulted. When a group of 10 parasites per test was employed a Nicholsonian type of response resulted. In an experimentally confined space, the parasites displayed a mutual behavioral interference resulting in emigration which accelerated as the parasite density increased. 相似文献