全文获取类型
收费全文 | 276篇 |
免费 | 20篇 |
专业分类
296篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 9篇 |
2014年 | 14篇 |
2013年 | 15篇 |
2012年 | 24篇 |
2011年 | 32篇 |
2010年 | 19篇 |
2009年 | 8篇 |
2008年 | 19篇 |
2007年 | 24篇 |
2006年 | 17篇 |
2005年 | 16篇 |
2004年 | 17篇 |
2003年 | 20篇 |
2002年 | 8篇 |
2001年 | 2篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有296条查询结果,搜索用时 0 毫秒
291.
292.
The amount of nuclear DNA, expressed as the C-value, was estimated for 13 marine halophytic plant species from six families. Plant material was collected in the nature reserve of the Strunjan saltpan in the Northern Adriatic and comprised all halophytic species inside the investigated area. Reproductive region of the shoot or root tips of halophytes were dissected, nuclei were Feulgen stained and 2C-values were measured by DNA image cytometry as follows: Crithmum maritimum (4.38 pg DNA), Artemisia caerulescens (6.43 pg), Aster tripolium (21.43 pg), Inula crithmoides (3.63 pg), Atriplex portulacoides (1.83 pg), A. prostrata (1.51 pg), Salicornia europaea (2.75 pg), Salsola soda (2.62 pg), Sarcocornia fruticosa (5.91 pg), Suaeda maritima (2.11 pg), Limonium angustifolium (5.06 pg), Puccinellia palustris (8.15 pg) and Ruppia cirrhosa (4.65 pg). With the exception of the C-value estimate for A. caerulescens, which has been listed in the Plant DNA C-values Database, the C-values represent the first estimates for all the examined species. In addition, the C-value for R. cirrhosa is also the first report for the family Ruppiaceae. The investigated halophytes had a smaller genome size compared to other known C-values for species within a particular family and also when compared to the mean values of dicots and monocots. The study also showed that halophylic annuals have a smaller genome size (2.49 pg) than perennial ones (7.45 pg DNA). 相似文献
293.
294.
Jasna Hrenovic Mirela Rozic Tomislav Ivankovic Anamarija Farkas 《Central European Journal of Biology》2009,4(3):397-403
The aim of this study was to determine the potential of phosphate (P) removal from wastewater by biosolids prepared by the
immobilization of P-accumulating bacteria onto organic bentonite. Organic bentonite was prepared by treating bentonite clay
with quaternary ammonium salt — cetyltrimetylammonium (CTA) bromide. Cation exchange capacity (CEC) of the bentonite was found
to be 179.0 meq/100 g of the dry bentonite. The CTA occupied ca. 175% of the CEC. Modification of bentonite with CTA in amounts
higher than 55% of the CEC resulted in the change of zeta potential of particles from negative to positive. Only in reactors
containing organic bentonite samples occupied with 3.5 and 28% of the CEC was P efficiently removed from wastewater by combined
adsorption and bacterial uptake in the biomass. Organic bentonite samples with higher CTA loadings (from 55 to 175% of the
CEC) showed bactericidal effects. To enhance P removal from wastewater in the aerated biological system, biosolids consisting
of P-accumulating bacteria and organic bentonite can be used, but special attention should be given to the configuration of
sorbed CTA molecules and its potential desorption. 相似文献
295.
296.
Tito Ureta Jasna Radojković 《BioEssays : news and reviews in molecular, cellular and developmental biology》1985,2(5):221-226
Microinjection of frog oocytes, a technique whose usefulness for studies on gene expression is already established, may be similarly helpful for the unraveling of several enigmas of cellular metabolism and its organization. 相似文献