全文获取类型
收费全文 | 299篇 |
免费 | 25篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 8篇 |
2014年 | 15篇 |
2013年 | 14篇 |
2012年 | 33篇 |
2011年 | 19篇 |
2010年 | 14篇 |
2009年 | 8篇 |
2008年 | 8篇 |
2007年 | 16篇 |
2006年 | 8篇 |
2005年 | 13篇 |
2004年 | 6篇 |
2003年 | 13篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1973年 | 3篇 |
1972年 | 7篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1907年 | 2篇 |
排序方式: 共有324条查询结果,搜索用时 15 毫秒
101.
Oliver Löwenstein Petra Leyendecker Eberhard A Lux Mark Blagden Karen H Simpson Michael Hopp Björn Bosse Karen Reimer 《BMC clinical pharmacology》2010,10(1):12
Background
Two randomised 12-week, double-blind, parallel-group, multicenter studies comparing oxycodone PR/naloxone PR and oxycodone PR alone on symptoms of opioid-induced bowel dysfunction in patients with moderate/severe non-malignant pain have been conducted. 相似文献102.
Polarized light based scheme to monitor column performance in a continuous foam fractionation column
Background
A polarized light scattering technique was used to monitor the performance of a continuously operated foam fractionation process. The S 11 and S 12 parameters, elements of the light scattering matrix, combined together (S 11 +S 12) have been correlated with the bubble size and liquid content for the case of a freely draining foam. The performance of a foam fractionation column is known to have a strong dependence on the bubble size distribution and liquid hold up in foam. In this study the enrichment is used as a metric, representative of foam properties and column performance, and correlated to the S 11 +S 12 parameter. 相似文献103.
Jang EB Holler T Cristofaro M Lux S Raw AS Moses AL Carvalho LA 《Journal of economic entomology》2003,96(6):1719-1723
Tests were conducted on wild Mediterranean fruit flies, Ceratitis capiata (Wiedemann), in Hawaii, Italy, and Kenya, and on sterile released flies in Florida and California with a new male attractant, (-)-ceralure B1. Compared on an equal dosage basis, Mediterranean fruit fly males were significantly more attracted to the (-)-ceralure B1 than to trimedlure in each of the sites tested except for California. Compared with the standard commercial 2 g trimedlure plug, 10 mg applied on cotton wicks (Kauai) was as attractive to wild males as trimedlure after the first 2 d of the test but not after 7 d. At a dose of 40 mg (50 times less than in the 2-g plug), the (-)-ceralure B1 was significantly more attractive to male flies than the 2-g trimedlure plug for the first week of service (Florida) but not after 2 wk. Studies using released sterile flies in Florida confirm our previous work on the improved attraction of (-)-ceralure B1 (40 mg) over trimedlure. However, this trend did not hold up in a single test conducted in a residential area in California that did not show a significant difference in attraction using 20 mg of compound. Future refinements in synthesis and costs of this compound and increased availability and testing will be needed before any final evaluation in the field can be carried out. 相似文献
104.
105.
Abstract. This paper presents a comparison of two alternative methods to describe and map vegetation: on the basis of plant species and growth forms, respectively. A stratified random sampling was taken from spontaneous vegetation in 1989 on the volcanic island of Pantelleria (near Sicily, Italy). Cartographic and other comparisons of the results from classification and ordination analysis suggest that the major differences were associated with differences in the time scale of the underlying processes. Species results (leading to floristic vegetation units) were representative of longer-term processes, growth-form results (leading to structural vegetation units) with shorter-term processes. Further implications of these results are discussed. 相似文献
106.
Radicle of matureEchinocactus platyacanthus embryo is approximately 320 m long and represents less then 1/7 of the embryonal axis length. The radicle-hypocotyl boundary can be distinguished according to the striking difference in the size and shape of cells in protoderm and procambium, as well as discontinuity and different number of the cell files in the ground meristem. The root cap is small, consists of 4 layers of cells covering the apex of the radicle. The upper limit of the root cap is approximately 100 m closer towards the radicle tip than the radicle-hypocotyl boundary. Ultrastructure of radicle cells showed numerous lipid bodies as is typical for other oily seeds. Protein bodies of variable structure were also present together with other cell structures. Striking differences in protein body structure were found when protoderm and ground meristem were compared. Several small globoid crystals were present in each protein body of the protoderm, while protein bodies in the radicle ground meristem mostly contained one large globoid crystal. X-ray microanalysis revealed presence of P, K and Mg in all analyzed globoid crystals. Fe, Ca and Zn were detected in some of them.Abbreviations EDX microanalysis
energy-dispersive X-ray microanalysis
- GC(s)
globoid crystals
- ICP spectroscopy
ion-coupled plasma spectroscopy
- LM
light microscopy
- PB(s)
protein bodies
- SEM
scanning electron microscopy
- TEM
transmission electron microscopy 相似文献
107.
108.
Desana Li >sková José Ruiz Ordóñez Alexander Lux Alfredo Piñeyro López 《Plant Cell, Tissue and Organ Culture》1994,36(3):339-343
Isolated embryos ofKarwinskia humboldtiana were cultured in vitro. The growth of embryos and development to plantlets on woody plant medium supplemented with indole-3-acetic acid 6.10-2 mol l–1, gibberellic acid (GA3) 3.10-2 mol l–1, and 6-benzylaminopurine (BA) 2 mol l–1 was obtained. Multiplication of shoots and rooting of excised shoots has been achieved. Callus formation on modified Murashige-Skoog medium supplemented with 1-naphthaleneacetic acid 10 mol l–1, GA3 14 mol l–1, and kinetin 5 mol l–1 on hypocotyls, or on root cultures on medium supplemented with 2.4-dichlorophenoxyacetic acid 10 mol l–1 and BA 10 mol l–1 was induced.Abbreviations BA
6-benzylaminopurine
- 2,4-d
2,4-dichlorophenoxyacetic acid
- GA3
gibberellic acid
- IAA
indole-3-acetic acid
- NAA
1-naphthaleneacetic acid
- TEM
transmission electron microscopy 相似文献
109.
Extraction is one of the commonest procedures in dentistry. Therefore, it is of interest to evaluate the post extraction complications in patients undergoing extractions of permanent teeth. A total of 70 adult patients who had undergone dental extractions and presented with post -operative complications were included in the study and evaluated. Data collected was statistically analyzed using SPSS software and results obtained. Most of the patients with post extraction complications were in the age group of 31-40 years (21.6%), followed by 21-30 (20.2%) and 61-70 years (20.2%). Dry socket (39.19%) was the common post extraction complication in our study especially in the age group of 31-40 years. There was a statistically significant association between age of the patients and the post extraction complications (p<0.001). In our study, post extraction complications were commonly observed in age group of 31-40 years with a predilection for males. Dry socket was the most common post extraction complication. Age of the patient has a significant effect on post extraction complications. However, gender, smoking habits and systemic diseases have no influence on post extraction complications. 相似文献
110.
Chemotaxis is an important feature of motile organisms that allows navigation through various environments. It enables them to detect nutrients and to avoid unfavorable or dangerous conditions. Motility and chemotaxis are widely acknowledged as important virulence factors for pathogenic bacteria. In this review, we try to explore the role of chemotaxis in the pathogenesis of spirochetes. Chemotaxis might be involved in tissue identification and penetration, and represents a possible mechanism for evasion of the host's immune defense. The recent development of genetic tools for pathogenic spirochetes and "tracking" techniques, employing fluorescent in situ hybridization (FISH), could revolutionize our understanding of the importance of chemotaxis for infection and persistence of these bacteria in their host. 相似文献