全文获取类型
收费全文 | 196篇 |
免费 | 8篇 |
国内免费 | 3篇 |
专业分类
207篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 1篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 12篇 |
2014年 | 6篇 |
2013年 | 28篇 |
2012年 | 6篇 |
2011年 | 3篇 |
2010年 | 6篇 |
2009年 | 7篇 |
2008年 | 6篇 |
2007年 | 14篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 3篇 |
排序方式: 共有207条查询结果,搜索用时 15 毫秒
61.
P. A. Anadu P. O. Elamah J. F. Oates 《Human ecology: an interdisciplinary journal》1988,16(2):199-208
Hunters and bushmeat retailers in Bendel State, Nigeria were interviewed from May through August 1982. Hunting was found to take place in all months of the year, but became more intense during the dry season. Twentyseven species of mammal were reported to be hunted, while 22 species of mammal and five species of reptile were found on sale. Retailers reported that the grasscutter (Thryonomys swinderianuswas the most popular species among their customers, followed by Maxwell's duiker, the brushtailed porcupine, and the bushpig. The grasscutter was also the most widely sold species, followed by the giant rat, monkeys, and Maxwell's duiker. Game animals were found to be shot and sold with little regard to existing laws, with the result that the larger mammals have become rare in Bendel and populations of the smaller ones have come under severe pressure. The bushmeat trade is highly commercialized, and substantial profits accrue to middlemen. Recommendations are made for the conservation of a natural resource, wildlife, that not only provides a significant amount of animal protein but also supports a large rural economy. 相似文献
62.
Godfrey C. Akani Pedro E. E. Aifesehi Fabio Petrozzi Luca Luiselli 《African Journal of Ecology》2015,53(3):278-286
The study of community composition shifts due to increased habitat modifications and deforestation is a primary issue in contemporary tropical community ecology theory. As the forest habitat conversion process has been very short in Africa relative to the evolutionary temporal scale, it is likely that animal communities are not at an equilibrium. The Upper Orashi Forest Reserve (Niger Delta region of Southern Nigeria) is a valuable case study as it is one of the few remnant deltaic swamp forest patches inside a highly developed and deforested region. In this paper, we investigated some aspects of the community ecology of reptiles of this forest area based on standardized field surveys across 26 study plots. Overall, we recorded 34 species, with the detected number of both species (34 versus 27) and individuals (562 versus 381) being higher during the wet season. Diversity/dominance diagrams showed similar trends in both seasons, but diversity measures showed that evenness was remarkably higher by wet season. Analysis of similarities (ANOSIM) confirmed that the species‐richness estimate generated by Chao's index was significantly higher for the wet season. However, the profiles of the diversity curves were comparable in the two seasons. The proportion of forest‐specialist species decreased compared to that observed at the same study area 15+ years ago, with a gradual process of biotic homogenization being apparent. 相似文献
63.
Cowpea, which has now become an important protein source for the teeming populace of Nigerians, especially those living in the humid agro-ecological zones of south-western Nigeria, is severely attacked by diseases. The causal agents of these diseases find the environment more conducive for survival and hence induced disease conditions in the host plant, causing significant yield reduction. This paper reviews the present situation of the cowpea diseases in the humid forest agro-ecologies of south-western Nigeria. 相似文献
64.
David Ekene Nwele Ikechukwu Oliver Onyali Milliam Okwudili Iwueze Michael Okpara Elom Ogbonna Elom Sabastian Uguru 《The Korean journal of parasitology》2022,60(3):173
Malaria remains a global health threat. Approximately 97% of the population is at risk in sub-Saharan countries, particularly Nigeria. This study compared the performance of 2 diagnostic methods in assessing malaria endemicity in the rural communities of Ebonyi State, Nigeria. A total of 1,140 study participants were screened for malaria parasite using Rapid Diagnostic Test kits (RDT) in the field, while thick and thin films for microscopy were examined in the laboratory. Our result showed that malaria prevalence was 56.8 by RDT and 38.6% by microscopic test. Age group under 10 years had the highest prevalence of 28.9% (RDT) and 23.6% (microscopy), respectively. The highest prevalence of 19.5% by RDT was recorded in Onicha Local Government Area, while the highest prevalence of 13.4% with microscopy was recorded in Ezza North Local Government Area. The sensitivity and specificity of microscopic examination were both 100%, while those of RDT were 95.5% and 75.9%, respectively. 相似文献
65.
66.
67.
Godwin Onuoha 《Ethnic and racial studies》2013,36(12):2182-2199
This article focuses on recent reconstructions of Igbo ‘memory’ by the Movement for the Actualization of the Sovereign state of Biafra (MASSOB). MASSOB is a second-generation Igbo separatist movement that draws on a collection of ‘memory repertoires’ to agitate for the self-determination and exit of the Igbo ethnic group from the Nigerian state into an alternative political and administrative arrangement known as the Republic of Biafra. The core issues relate to dual narratives generated by the Nigerian–Biafran War. While the state shapes the official history, memories and narratives of the war to suit its own vision, interests and politics, MASSOB contests these official views as the sole legitimate framework for remembering and interpreting the war, but still connects to the war as a war of Igbo national liberation. These contestations provide the context for the enactment of memory claims and counterclaims, and their association with political violence in contemporary Nigeria. 相似文献
68.
As a part of the surveillance effort to monitor the ecological status of Omo Biosphere Reserve in the southwestern region of Nigeria, the aerobic heterotrophic bacterial and fungal communities of the topsoil were investigated in March 1995 and April 1996, before the onset of the rainy season. Four distinct wood‐tree plantations, a core strict nature reserve (SNR) area, and a buffer zone were sampled. The topsoil samples (7.5 cm depth), including the litter, were taken with an auger (8 cm diameter) and transported to the laboratory in polyethylene bags. One‐gram dry weight equivalent of sample was suspended in 10 ml sterile water, and serial dilutions from it were used for the estimation of bacterial and fungal densities. The bacterial and fungal densities ranged in the order of 106 and 103 cfu/g, respectively. Out of the 18 bacterial and 16 fungal species that were obtained, 13 and 12, respectively, were isolated from the core SNR. About 46 to 69 percent of the bacteria and 50 to 83 percent of the fungi species found in the SNR were absent in different combinations in the plantations and the buffer zone; these variations were significant among the sites monitored. The bacterial and fungal species compositions were significantly different between the SNR and each of the other sites. Proportional distributions within the sites were significant only for the bacterial communities. It would appear that plantation and human activities have caused significant changes in the distribution and species richness of the heterotrophic bacterial and fungal communities relative to the undisturbed SNR area of the Omo Biosphere Reserve. 相似文献
69.
Zulfiya Yunus Lijun Liu Hong Wang Le Zhang Xiaolan Li Tingting Geng Longli Kang Tianbo Jin Chao Chen 《Gene》2013
Pharmacogenomic variant information is well known for major human populations; however, this information is less commonly studied in minorities. In the present study, we genotyped 85 very important pharmacogenetic (VIP) variants (selected from the PharmGKB database) in the Kyrgyz population and compared our data with other four major human populations including Han Chinese in Beijing, China (CHB), the Japanese in Tokyo, Japan (JPT), a northern and western Europe population (CEU), and the Yoruba in Ibadan, Nigeria (YRI). There were 13, 12 and 16 of the selected VIP variant genotype frequencies in the Kyrgyz which differed from those of the CHB, JPT and CEU, respectively (p < 0.005). In the YRI, there were 32 different variants, compared to the Kyrgyz (p < 0.005). Genotype frequencies of ADH1B, AHR, CYP3A5, PTGS2, VDR, and VKORC1 in the Kyrgyz differed widely from those in the four populations. Haplotype analyses also showed differences among the Kyrgyz and the other four populations. Our results complement the information provided by the database of pharmacogenomics on Kyrgyz. We provide a theoretical basis for safer drug administration and individualized treatment plans for the Kyrgyz. We also provide a template for the study of pharmacogenomics in various ethnic minority groups in China. 相似文献
70.
O. A. Oyelami Dr. S. M. Maxwell K. A. Adelusola T. A. Aladekoma A. O. Oyelese 《Mycopathologia》1995,132(1):35-38
Autopsy brain (cerebrum) specimens from 18 kwashiorkor children and 19 children who had died from a variety of other diseases, at the Obafemi Awolowo Teaching Hospital complex, Ile-Ife, Nigeria, were analysed for the presence of aflatoxins using high-performance liquid chromatography. Aflatoxins were detected in 81%, 15 specimens in each group. More than one type of aflatoxin was detected in 14 (37.8%) of all the specimens. Aflatoxin B1 and its reversible metabolite, aflatoxicol, were detected in 11 brain specimens of patients with kwashiorkor and 6 of those who died of other miscellaneous diseases; out of these 6, two died from measles and its complications. The frequent detection of aflatoxins in the brains of these children and sometimes in multiple forms may suggest that aflatoxins are stored in the brain tissue which could be related to the lipophilic nature of these compounds. These findings also suggest that although many children in the tropics are exposed to aflatoxins, the accumulation of aflatoxin B1 and aflatoxicol in the brains of kwashiorkor children may be a result of an impaired metabolism of these compounds by these children. 相似文献