全文获取类型
收费全文 | 126篇 |
免费 | 17篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 8篇 |
2011年 | 6篇 |
2010年 | 10篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 6篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1998年 | 1篇 |
1995年 | 3篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1907年 | 1篇 |
排序方式: 共有143条查询结果,搜索用时 312 毫秒
121.
Viktoria Wagner Milan Chytrý Borja Jiménez‐Alfaro Jan Pergl Stephan Hennekens Idoia Biurrun Ilona Knollová Christian Berg Kiril Vassilev John S. Rodwell Željko Škvorc Ute Jandt Jörg Ewald Florian Jansen Ioannis Tsiripidis Zoltán Botta‐Dukát Laura Casella Fabio Attorre Valerijus Rašomavičius Renata Ćušterevska Joop H. J. Schaminée Jörg Brunet Jonathan Lenoir Jens‐Christian Svenning Zygmunt Kącki Mária Petrášová‐Šibíková Urban Šilc Itziar García‐Mijangos Juan Antonio Campos Federico Fernández‐González Thomas Wohlgemuth Viktor Onyshchenko Petr Pyšek 《Diversity & distributions》2017,23(9):969-981
122.
L. M. Hernández-Triana V. A. Brugman P. Pramual E. Barrero N. I. Nikolova I. Ruiz-Arrondo A. Kaiser A. Krüger S. Lumley H. C. Osório A. Ignjatović-Ćupina D. Petrić M. Laure Setier-Rio R. Bødker N. Johnson 《Medical and veterinary entomology》2020,34(1):86-96
In mainland Europe, the mosquito species Culex modestus Ficalbi (1890) is a bridge vector for West Nile virus (WNV) from its natural bird-mosquito cycle to mammals. The present study assessed the genetic diversity of Cx. modestus, as well as related Culex species, using the mitochondrial COI DNA barcoding region and compared this with the population structure across Europe. A haplotype network was mapped to determine genealogical relationships among specimens. The intraspecific genetic diversity within individual Culex species was below 2%, whereas the interspecific genetic divergence varied from 2.99% to 13.74%. In total, 76 haplotypes were identified among 198 sequences. A median-joining network determined from 198 COI sequences identified two major lineages that were separated by at least four mutation steps. A high level of intraspecific genetic diversity was not detected in Cx. modestus in samples submitted from different European populations, which indicates that morphologically identified specimens represent a single species and not a species complex. Therefore, it is deduced that different populations of Cx. modestus will show a similar potential to transmit WNV, lending support to concerns that the population present in southeast England represents a risk of transmission to humans. 相似文献
123.
A sample of 198 asp (Aspius aspius) was collected over a 28.5 km long section of the Danube River, upstream and downstream from the mouth of the Sava River, in order to provide information on population structure, diet, growth, and condition of this species. Total body lengths of sampled fish were 90–405 mm, and body weights 5–567 g. The sample was predominantly sub‐adult fish aged 0+ to 4+ years. Sexually immature asp prevailed over the sexually mature asp. The sex ratio (1.4 : 1) was biased toward males. Male asps in the Danube become sexually mature only in their fifth year of life, and the females even later, as no sexually mature females were caught. The diet spectrum consists exclusively of fishes; of seven determined prey species, most important are bleak Alburnus alburnus, roach Rutilus rutilus, and goldfish Carassius auratus. Highest value of the seasonal vacuity index is in November (Iv = 94.1), and the smallest in July (Iv = 35.6). Trophic niche breadth is largest in May (H = 1.40), and smallest in November (H = 0.00). The largest average number of prey items is found in age class 4+ (2.33), the smallest in age class 0+ (1.00). Von Bertalanffy growth parameters are L∞ = 526.46, K = 0.28, and t0 = 0.22. The length–weight relationship is described as log W = ?5.16 + 3.03 log L. Fulton’s condition factor increases with fish length, from 0.70 to 0.83. Regarding seasonal fluctuations, this factor begins to increase in late spring, with the trend continuing until autumn, and then decreasing from autumn to spring. 相似文献
124.
125.
S. Vaselek G. Oguz N. Ayhan Y. Ozbel P. Kadriaj A. I. Ćupina E. Velo N. Muja D. Baymak M. Alishani S. Toz M. Nalcaci K. Sherifi R. Charrel B. Alten D. Petrić 《Medical and veterinary entomology》2020,34(4):394-401
In the past decade, leishmaniasis seems to be re-emerging in Balkan countries. There are serious implications that Kosovo is a visceral leishmaniasis endemic region with autochthonous transmission; nevertheless, surveillance of vectors, reservoirs or the disease is not yet established. Gaining knowledge about sandfly vector species is a prerequisite for the development of a monitoring and control plan in the future. After a long gap in research of over 70 years, sandfly studies in Kosovo were resumed in 2014. During this presence/absence study, nine sandfly species were detected: Phlebotomus papatasi, Ph. perfiliewi, Ph. tobbi, Ph. neglectus, Ph. simici, Ph. balcanicus, Ph. alexandri, Ph. mascittii and Sergentomyia minuta. Three species are new with regard to the fauna of Kosovo – Ph. alexandri, Ph. balcanicus and Ph. mascittii. Besides increased diversity, changes in the number of collected specimens and distribution range of species were recorded, with Ph. neglectus being the most dominant species with the widest distribution. Testing of randomly chosen females for Leishmania spp. DNA resulted the in detection of L. tropica in a specimen of Ph. neglectus. The presence of numerous vector species in the sandfly fauna of Kosovo pose a threat for the re-emergence of vector-borne diseases. Therefore, continuous surveillance is recommended with regular updates on vector distribution and abundance. 相似文献
126.
Defensive Secretions in Callipodella fasciata (Latzel, 1882; Diplopoda,Callipodida, Schizopetalidae)
Slobodan E. Makarov Božidar P. M. Ćurčić Ljubodrag V. Vujisić Milka B. Jadranin Vele V. Tešević Ivan M. Vučković Tatjana L. Sekulić Srećko B. Ćurčić Bojan M. Mitić 《化学与生物多样性》2011,8(7):1284-1289
The small millipede Callipodella fasciata secretes an earthy smell when disturbed. This secretion was obtained by CH2Cl2 extraction from specimens of both sexes and was identified by GC/MS analyses to be composed of p‐cresol (96.5%), phenol (3.5%), and p‐ethylphenol (traces). This is the first identification of these compounds in an epigean European callipodidan species and the first report of intergeneric differences in the chemical composition of defensive secretions in callipodidans. These compounds have repellent, antimicrobial, and antifungal properties. 相似文献
127.
Thomas Wiedl Mathias Harzhauser Andreas Kroh Stjepan Ćorić Werner E. Piller 《Facies》2014,60(4):865-881
The Leitha Mountains in Austria are a chain of hills separating the southern Vienna Basin and the Danube Basin. The Lower East Alpine basement of the Leitha Mts. is covered by Middle Miocene sediments of the Badenian and Sarmatian regional stages. Close to the northeastern margin of these hills, upper Badenian successions are exposed, which are part of a coralline algal-dominated carbonate platform with hydrodynamically influenced sediments. Six sections have been logged and subjected to detailed investigation and sampling. They are characterized by inclined beds (foresets), which have been formed by unidirectional transport of sediments. Large-scale asymmetrical ripples indicate strong currents affecting shallow topset deposits. Generally, this hydrodynamically controlled sedimentation, documented by seven facies types, is reflected in a strongly reduced diversity of facies and biota, contrary to the older facies-rich middle Badenian sediments. This change from biologically to hydrodynamically controlled sedimentation led to a reduction in diversity of facies and biota. Sediment transport, however, caused secondary mass occurrences of echinoids or foraminifers derived from seagrass meadows. This study unravels the distribution and differences of middle and upper Badenian deposits of the Leitha Mountains and the influence of tectonic activity. Changes in hydrodynamics on the Leitha Platform are linked to the formation of the Danube Basin starting in the middle Badenian when a new seaway to the southeast has started to form. 相似文献
128.
VIOLETA BEŠIREVIĆ 《Bioethics》2010,24(3):105-112
This article explores universal normative bases that could help to shape a workable legal construct that would facilitate a global use of advance directives. Although I believe that advance directives are of universal character, my primary aim in approaching this issue is to remain realistic. I will make three claims. First, I will argue that the principles of autonomy, dignity and informed consent, embodied in the Oviedo Convention and the UNESCO Declaration on Bioethics and Human Rights, could arguably be regarded as universal bases for the global use of advance directives. Second, I will demonstrate that, despite the apparent consensus of ethical authorities in support of their global use, it is unlikely, for the time being, that such consensus could lead to unqualified legal recognition of advance directives, because of different understandings of the nature of the international rules, meanings of autonomy and dignity which are context‐specific and culture‐specific, and existing imperfections that make advance directives either unworkable or hardly applicable in practice. The third claim suggests that the fact that the concept of the advance directive is not universally shared does not mean that it should not become so, but never as the only option in managing incompetent patients. A way to proceed is to prioritize work on developing higher standards in managing incompetent patients and on progressing towards the realization of universal human rights in the sphere of bioethics, by advocating a universal, legally binding international convention that would outlaw human rights violations in end‐of‐life decision‐making. 相似文献
129.
130.
Tihana Marček Mirta Tkalec Željka Vidaković-Cifrek Marin Ježić Mirna Ćurković-Perica 《Acta Physiologiae Plantarum》2014,36(7):1739-1747
Salinity is an important abiotic factor that limits plant growth and development. The influence of salt stress induced by sodium chloride on plant growth, proline content, level of lipid peroxidation and activities of antioxidative enzymes was studied in F1 hybrid DH10 and four dihaploid lines (207B, 238C, 239K, 244B) of tobacco (Nicotiana tabacum L.). Dihaploids were obtained from anther-derived haploids of hybrid DH10 and were previously proved to be tolerant to Potato virus Y (PVY). In our study, plants were grown in vitro and exposed to NaCl (100 and 200 mM) for 33 days. All dihaploids and hybrid DH10 showed reduced growth after NaCl treatment. They accumulated significant amounts of sodium and proline in response to salt stress as have already been observed in tobacco and other plant species. In tobacco exposed to NaCl the lipid peroxidation level did not increase and activities of superoxide dismutase (SOD), guaiacol peroxidase (POD), ascorbate peroxidase and catalase (CAT) mostly did not change significantly. The exception was line 239K where salt induced higher activities of SOD, CAT and POD. Two (238C and 244B) out of four dihaploids appeared more susceptible to salt stress as they showed weak growth in correlation with high proline and sodium content. Therefore, it seems that salt tolerance is not associated with tolerance to PVY. Variations in malondialdehyde and proline content as well as in enzymes activities observed among tobacco lines imply that dihaploids have different genetic properties which might result in different sensitivity to NaCl. 相似文献