全文获取类型
收费全文 | 351篇 |
免费 | 32篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 385篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 19篇 |
2020年 | 21篇 |
2019年 | 13篇 |
2018年 | 31篇 |
2017年 | 21篇 |
2016年 | 27篇 |
2015年 | 18篇 |
2014年 | 32篇 |
2013年 | 40篇 |
2012年 | 22篇 |
2011年 | 33篇 |
2010年 | 17篇 |
2009年 | 24篇 |
2008年 | 8篇 |
2007年 | 9篇 |
2006年 | 11篇 |
2005年 | 3篇 |
2004年 | 8篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有385条查询结果,搜索用时 15 毫秒
381.
382.
Scots pine (Pinus sylvestris L.) wood is the most frequently used building material in old churches of Central Poland. In the article, the density and compressive strength of Scots pine heartwood samples taken from old churches from the sixteenth, seventeenth, and eighteenth century were examined. The properties of the old wood were compared with contemporary wood of similar density. The results showed better quality of the ancient wood as compared to modern wood. 相似文献
383.
Katarzyna Grelewska-Nowotko Jarosław Nowosielski Magdalena Żurawska-Zajfert Paweł Częstobor Czembor Sławomir Sowa 《Food Biotechnology》2014,28(3):232-249
PCR-based methods are widely used in the European Union and in other countries for the detection, identification, and quantification of genetically modified organisms (GMOs). The preparation of good-quality DNA from plant samples for GMO detection can be a challenging task, particularly if the DNA will be used for quantitative analysis. Two DNA extraction methods, namely manual (NucleoSpin Food kit from Machery-Nagel) and high-throughput partially automated (NucleoMag Plant kit from Machery-Nagel) methods, which utilize different DNA separation principles, were used for the isolation of DNA from maize flour samples. Despite the higher DNA recovery obtained using the high-throughput isolation method, a lower PCR efficiency was achieved, most likely due to the presence of PCR inhibitors in the extracts. We found both DNA extraction methods suitable for GMO analysis. 相似文献
384.
Pressurized planar electrochromatography (PPEC) is the mode which offers much higher separation efficiency in comparison to conventional planar chromatography, including both higher performance and much higher speed of separation. In this paper, we present a new device for performing PPEC in which the whole area of the chromatographic plate is pressurized. Both electrodes (anode and cathode) are washed with the mobile phase during the experiment, which prevents gas bubbles from collection in the region of the electrodes. This device enables directly controlling the flow rate of the mobile phase during the electrochromatography process. Mobile phase control offers the possibility of researching the influence of various properties of the PPEC system on separation efficiency. One important relationship to investigate is plate height vs mobile phase flow rate. This relationship helps to choose the optimal value of the mobile phase flow rate during the separation process. Considerable difference in shape of this relationship is demonstrated for conventional planar chromatography plates and high performance planar chromatography plates. Examples of the influence of some properties of the separating system on flow rate of the mobile phase are demonstrated, such as the buffer concentration in the mobile phase, the pH value of the buffer solution of the mobile phase, the type of chromatographic plate, and the voltage applied to the electrodes. 相似文献
385.
Daria Różycka Dr. Aleksandra Kowalczyk Dr. Marta Denel-Bobrowska Olga Kuźmycz Dr. Magdalena Gapińska Prof. Paweł Stączek Prof. Agnieszka B. Olejniczak 《ChemMedChem》2023,18(7):e202200666
Synthesis of acridine derivatives that act as DNA-targeting anticancer agents is an evolving field and has resulted in the introduction of several drugs into clinical trials. Carboranes can be of importance in designing biologically active compounds due to their specific properties. Therefore, a series of novel acridine analogs modified with carborane clusters were synthesized. The DNA-binding ability of these analogs was evaluated on calf thymus DNA (ct-DNA). Results of these analyses showed that 9-[(1,7-dicarba-closo-dodecaborane-1-yl)propylamino]acridine ( 30 ) interacted strongly with ct-DNA, indicating its ability to intercalate into DNA, whereas 9-[(1,7-dicarba-closo-dodecaborane-1-yl)propanamido]acridine ( 29 ) changed the B-form of ct-DNA to the Z form. Compound 30 demonstrated cytotoxicity, was able to inhibit cell proliferation, arrest the cell cycle in the S phase in the HeLa cancer cell line, and induced the production of reactive oxygen species (ROS). In addition, it was specifically localized in lysosomes and was a weak inhibitor of Topo IIα. 相似文献