全文获取类型
收费全文 | 144篇 |
免费 | 12篇 |
专业分类
林业 | 38篇 |
农学 | 11篇 |
基础科学 | 1篇 |
19篇 | |
综合类 | 9篇 |
农作物 | 9篇 |
水产渔业 | 23篇 |
畜牧兽医 | 33篇 |
园艺 | 2篇 |
植物保护 | 11篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 3篇 |
2013年 | 5篇 |
2012年 | 6篇 |
2011年 | 10篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 10篇 |
2007年 | 12篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 6篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有156条查询结果,搜索用时 140 毫秒
141.
Mohammad Shaheed Hossain Chowdhury ;Md. Abdul Halim ;Nur Muhammed ;Farhana Haque ;Masao Koike 《林业研究》2008,19(3):245-251
A study was conducted to explore the traditional utilization pattern and indigenous management practices of wild date palm (Phoenix sylvestris Roxb) in the rural agrarian regions of Bangladesh. A multistage sampling method with 10% intensity and a semi-structured questionnaire were used for the study. The farmers manage the palm mainly for sap production with which sugar based secondary goods are manufactured. The sap is either used fresh as drink or after some sort of processing as molasses and/or alcoholic beverage. Seven diversified sites support the palm as its habitat and most palms (20.40%) occur in orchards. Besides growing naturally, the palm is also established in orchards using the wildings as the staple planting material. Although the medium category farmers own most of the palms (33%), a considerable portion (28.68%) of it is managed by the landless farmers, who earn a substantial livelihood from the palms. The farmers practice their own indigenous wisdom in every stage of the palm's maintenance from planting through tapping for sap collec- tion to the processing of products. If managed more scientifically on a sustainable basis with the collaboration of farmers' indigenou~ knowledge, this familiar palm could be able to support the rural economy of the country to a great extent. Side by side, it would also be able to contribute to the richness of biodiversity in the region. 相似文献
142.
M. A. Kabir Chowdhury Dominique P. Bureau Manik L. Bose Madan Dey 《Aquaculture Economics & Management (Blackwell Science)》2013,17(2):151-169
Applications of a rapid appraisal approach to identify locally available feed ingredients in feed formulation, production, and socio-economics of Nile tilapia aquaculture in Bangladesh are discussed. Three diets of 35%, 30%, and 25% crude protein were formulated using locally available ingredients, and their essential amino acid profiles were assessed for Nile tilapia. Six production scenarios were constructed using these diets and two culture periods of 100 and 150 days were considered. The production scenarios with 35% protein yielded the highest productivity and profitability over the 150-day culture period followed by the 30% protein scenario. Identification of locally available ingredients and their application in small-scale Nile tilapia aquaculture may lead to: (1) increased availability of inexpensive sources of fish production for poor people; (2) increased fish consumption; (3) increased self employment and involvement of women in productive activities; and (4) increased household income to reduce poverty. 相似文献
143.
Differential behaviour of sheath blight pathogen Rhizoctonia solani in tolerant and susceptible rice varieties before and during infection 下载免费PDF全文
This study characterized the early infection and establishment of the sheath blight pathogen Rhizoctonia solani on a tolerant rice variety, Swarnadhaan (IET 5656), and a susceptible variety, Swarna (MTU 7029). Assays using whole plants showed that disease severity was higher in Swarna than Swarnadhaan. In a detached leaf assay, Swarnadhaan showed a disease index that was 50% less than that with Swarna. Rhizoctonia solani exhibited different growth behaviour in the tolerant and susceptible varieties. The pathogen showed more hyphal growth in the susceptible host than in the tolerant variety. It also showed profuse branching, making intimate contact with the host surface to form more inter‐ and intracellular structures, and greater sclerotial development in the susceptible host compared to the tolerant one. Using light and scanning electron microscopy, it was observed for the first time that the pathogen could intercept host surface structures and use these for anchorage or penetration. Transformed R. solani, expressing green fluorescent protein, was observed using confocal laser scanning microscopy to investigate pathogen behaviour, including the formation of infection cushions and subsequent colonization of the host tissues. This is the first ultrastructural report to characterize the differential behaviour of the sheath blight pathogen in the vicinity and within tolerant and susceptible rice plants. 相似文献
144.
Mohammad Shaheed Hossain Chowdhury Md. Mizanur Rahman Masao Koike Nur Muhammed Kazi Mohammad Salahuddin Md. Abdul Halim Narayan Saha Md. Parvez Rana Md. Jahirul Islam 《Small-Scale Forestry》2010,9(1):93-105
Throughout the world ornamentation of body with mehedi (Lawsonia inermis L.) leaf paste, with the trade name ‘henna body art’ is becoming increasingly popular. The worldwide increasing demand of
mehedi leaf encourages many countries to adopt commercial farming of the plant. Farmers living in central Bangladesh recently
commenced small-scale mehedi farming, primarily with the purpose of meeting national demand. A total of 182 farmers are engaged
in mehedi farming and a study was conducted among 36 of them (a 20% random sample) to explore indigenous management techniques,
marketing, livelihood potential and constraints of the enterprise. Farming was reported to be the major primary occupation
of the study area. An average of 0.05 ha land of the respondents was used for mehedi cultivation, which constituted 16.7%
of their average farm land. The farmers applied their own indigenous technology in every aspect of the farming, using branch
cuttings as the only propagation material. The financial analysis indicated that mehedi farming is a profitable and attractive
option for rural livelihoods [with an estimated net present value of Tk (Bangladeshi currency unit, 1 US $ = 68 Taka (as of
May, 2009).) 179,500 for 0.1 ha plantation]. However, the enterprise faces several constraints, including absence of a nursery
for supplying planting materials, storage and effective marketing facilities, available capital for investment, improved technology,
and above all, government support. If the government extends cooperation by assisting farmers with training, technology, credit
and market development, mehedi farming could become an important revenue-earning enterprise in the small-scale cottage sector
of Bangladesh. 相似文献
145.
146.
Our goal was to identify the cells expressing Pit-1 protein in chicken anterior pituitary. The anterior pituitaries were collected from laying hens after perfusion with formalin-PBS, and fixed with Bouin's fixative followed by paraffin embedding. Sections of the anterior pituitaries were immunostained for Pit-1 in the first staining sequence followed by staining for 6 types of pituitary hormones in the second sequence. Pit-1 positive nuclei were observed in the glandular cells in both the cephalic and caudal lobes. Pit-1 immunoreaction products were colocalized in the glandular cells immunopositive for growth hormone, thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, adrenocorticotropic hormone or prolactin. These results indicate that Pit-1 protein induction occurs in 6 types of glandular cells, suggesting that Pit-1 may regulate hormone synthesis in each glandular cell in the chicken pituitary. 相似文献
147.
Avian pox in a whistling swan 总被引:1,自引:0,他引:1
148.
149.
One mouse click on fish seminal vesicle (SV) in Pub-Med reveals a limited number of articles that give various pieces of information
on its restricted distribution, origin, structure, relation with testis, and physiology. Although in the last decade significant
progress has been made with respect to the nature and multiple functions of SV secretions, and new aspects are steadily being
uncovered, much still remains to be known before we can realize its potential application in fisheries. This review is an
attempt to provide an update on recent research on various aspects of the SV and its secretory products in teleosts. The available
data suggest a significant role of SV and its products in the maturation and nutrition of sperm cells, in the maintenance
of their integrity and viability, and the enhancement of spawning performance and fertilization. 相似文献
150.
Multi-criteria evaluation approach to GIS-based land-suitability classification for tilapia farming in Bangladesh 总被引:1,自引:0,他引:1
M. Shahadat Hossain Sayedur Rahman Chowdhury Nani Gopal Das M. Moshiur Rahaman 《Aquaculture International》2007,15(6):425-443
Site selection is a key factor in any aquaculture operation, because it affects both success and sustainability. It can, moreover,
solve conflicts between different activities, making rational use of the land. This study was conducted to identify suitable
sites for development of Nile tilapia (Oreochromis niloticus) farming in Sitakunda Upazila (sub-district), Bangladesh, using GIS-based multi-criteria evaluation of water and soil quality,
topography, infrastructure and socio-economic factors. ASTER image and eighteen thematic layers were analyzed using ENVI and
ArcView software to identify the suitable areas for tilapia farm development. A constraint layer was used to exclude areas
from suitability maps that cannot be allowed to implement tilapia farming. A series of GIS models were developed to identify
and prioritize the most suitable areas for tilapia farming. The output of the model clearly indicates the location and extent
of tilapia farming areas on different suitability scales, i.e. most suitable (7,744 ha), moderately suitable (2,479 ha), and
not suitable (838 ha). Model outputs were assessed against field verification data, and were consistent. Because existing
aquaculture covers only 1,540 ha of land in the study area, the potential for expanding tilapia farms should take into consideration
socio-political and environmental issues. The results are encouraging in terms of tilapia culture development and suggest
that grassland–agriculture areas could be used for sustainable development of tilapia farming to diversify the economic activities
of rural communities. 相似文献