全文获取类型
收费全文 | 58篇 |
免费 | 0篇 |
专业分类
林业 | 5篇 |
农学 | 11篇 |
10篇 | |
综合类 | 5篇 |
农作物 | 2篇 |
水产渔业 | 8篇 |
畜牧兽医 | 15篇 |
植物保护 | 2篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 5篇 |
2011年 | 1篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有58条查询结果,搜索用时 15 毫秒
51.
Dry Matter Accumulation and Associated Changes in Biochemical Parameters during Wheat Grain Development 总被引:1,自引:0,他引:1
Field experiments were conducted in Rajkot, Gujarat, India comparing three cultivars of wheat, viz. Raj-1555, Lok-1 and Sonera, all differing in their grain yield. Apical grain of the seventh spikelet from the main spike was selected as a representative grain in each cultivar and analyzed at 4-day intervals from anthesis to maturity for dry matter, starch, sugars and protein content. The data for dry matter accumulation and starch content were fitted to a quadratic polynomial exponential which revealed a close correspondence between these two parameters. The absolute rates of starch and dry matter accumulation were highest in Lok-1 followed by Sonera and Raj-1555, respectively; however, the duration of the grain-filling observed from these curves was highest in Raj-1555. The maximum weight of the grain at harvest was in Lok-1 (80 mg) followed by Raj-1555 (71 mg) and Sonera (50 mg), respectively. Increase in the starch content coincided well with dry matter accumulation. Reducing and nonreducing sugars were high during early stage but declined with advances in growth up to almost middle of the grain growth; high levels were even found at later stages. Although protein increased with increasing grain growth in Raj-1555 and Sonera, no clear trend was observed in Lok-1 in relation to dry matter accumulation. The results are discussed in relation to the use of polynomial functions and the contribution of photosynthate supply from various plant parts in relation to grain growth and yield in wheat. 相似文献
52.
A. K. Joshi S. V. Chanda P. N. Krishnan P. P. Vaishnav Y. D. Singh 《Journal of Agronomy and Crop Science》1986,157(1):1-12
Three hybrids of Pennisetum americanum L. Leeke were analyzed for growth and photosynthetic components during early growth and compared with their respective parents. Growth in terms of shoot length, fresh weight and dry weight along with the chlorophylls, and Hill activity revealed better parental and/or mid parental heterosis in all the hybrids over their respective parents. However, PEPcase activity displayed heterosis only in BJ-104. In other two hybrids no heterosis over the parents could be observed indicating thereby that the activity of this enzyme may not be rate limiting in parental lines.
Nevertheless, it appears that in pearl millet hybrids improved photosynthetic apparatus as observed in chlorophyll contents and Hill reaction may be one of the early expressions of hybrid vigour. 相似文献
Nevertheless, it appears that in pearl millet hybrids improved photosynthetic apparatus as observed in chlorophyll contents and Hill reaction may be one of the early expressions of hybrid vigour. 相似文献
53.
Chandra Prakash Kushwaha Shri Kant Tripathi Gopal Shankar Singh Kaushlendra Pratap Singh 《Annals of Forest Science》2010,67(3):310-310
54.
Boonmar S Chanda C Markvichitr K Chaunchom S Yingsakmongkon S Yamamot S Morita Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(8):853-855
This is the first report regarding isolation of Campylobacter in caecum and bile samples obtained from ruminants in Vientiane, Lao PDR. Campylobacter was isolated from 3 (1.6%) of the 184 caecum samples and 1 (1.0%) of the 100 bile samples obtained from buffaloes. Three of the 4 isolates were determined to be C. jejuni, which was detected in 2 caecum samples and 1 bile sample; the other caecum sample contained C. fetus. Campylobacter was not isolated from any of the 82 cattle caecum samples. Our results suggest that cattle and buffaloes may not be important sources of Campylobacter food poisoning in Lao PDR. 相似文献
55.
56.
Takudzwa C. Madzivanzira Josie South Bruce R. Ellender Russell Chalmers Gethings Chisule Christine R. Coppinger Fernandu H. Khaebeb Francois J. Jacobs Machaya Chomba Bumango Musando Chanda Mwale Tamuka Nhiwatiwa Craig L. Rennie Naomi Richardson Olaf L. F. Weyl 《水产资源保护:海洋与淡水生态系统》2021,31(11):3156-3168
- Crayfish are invasive polytrophic keystone species, which are phylogenetically unique on the African continent. The Australian redclaw crayfish Cherax quadricarinatus is invasive in southern African freshwater systems including the Zambezi River Basin. Surveys conducted across the Zambezi Basin (Botswana, Zimbabwe, Namibia and Zambia) between 2017 and 2019 showed that C. quadricarinatus is broadly distributed across the Upper and Middle Zambezi and is rapidly spreading through natural and human-mediated means across several ecoregions.
- The probability of capture (Pcapture), catch per unit effort (CPUE) and population characteristics of C. quadricarinatus from the recent Barotse floodplain invasion were compared with older invasions from Lake Kariba and Kafue River.
- The Pcapture and CPUE of C. quadricarinatus in the recently invaded region of the Barotse floodplain were similar to those of the older invasions. Mass and carapace length of C. quadricarinatus from the Barotse floodplain were significantly lower than those of C. quadricarinatus from the older invasions. Sex ratios differed significantly between the three invasive populations. The Barotse floodplain population had a disproportionate investment in females (65.3%) and intersex individuals (8.4%). No crayfish were detected in the Zambezian Headwaters or the Okavango Floodplains ecoregions, but current spread rates are 49 km yr−1 downstream and 12 km yr−1 upstream.
- Investment in population management and the prevention of spread will have high conservation value across the invaded regions in order to restrict crayfish ecological impacts via direct predation and competition. In areas where crayfish are in high abundance, existing fisheries are affected through damage to nets, leading to increased net abandonment and ghost gear pollution in invaded regions.
- The emphasis should be on developing cohesive transboundary biosecurity policies in southern Africa to limit further spread that will threaten the integrity of freshwater ecosystems. However, long-term monitoring is needed to gauge invasion risk to sensitive areas such as the Okavango Floodplains ecoregion and determine field-based ecological impacts.
57.
Thangaraj R Swaminathan Achamveettil Gopalakrishnan Valaparambil S Basheer Basdeo Kushwaha Kavungal A Sajeela 《Aquaculture Research》2012,43(4):498-508
A fibroblastic‐like cell line was established from the ornamental fish, red‐line torpedo (Puntius denisonii). The red‐line torpedo fin (RTF) cell line is being maintained in Leibovitz's L‐15 medium supplemented with 10% fetal bovine serum (FBS) for over 1 year at 28 °C on a continuous basis in normal atmosphere. The growth rate of RTF cells increased as the FBS proportion increased from 5% to 20% at 28 °C with optimum growth at the concentrations of 10% FBS. The morphology of RTF cell was predominantly fibroblastic like. Propagation of these cell lines was serum dependent, with a low plating efficiency (<15%). Karyotyping analysis of RTF cells at the 25th passage indicated that the modal chromosome number was 2n=50. The cell line was cryopreserved in liquid nitrogen at ?196 °C and could be recovered from storage after 6 months with good cell viability. Polymerase chain reaction amplification of a fragment of two mitochondrial genes, 16S rRNA and CO1, confirmed the identity of these cell lines with those reported from this animal species, confirming that the cell lines originated from P. denisonii. The bacterial extracellular products from Vibrio cholerae MTCC3904 and Aeromonas hydrophila were found to be toxic to RTF. The cell lines were not susceptible to viral nervous necrosis virus, a marine fish virus. 相似文献
58.
M. S. Reed I. Fazey L. C. Stringer C. M. Raymond M. Akhtar‐Schuster G. Begni H. Bigas S. Brehm J. Briggs R. Bryce S. Buckmaster R. Chanda J. Davies E. Diez W. Essahli A. Evely N. Geeson I. Hartmann J. Holden K. Hubacek A. A. R. Ioris B. Kruger P. Laureano J. Phillipson C. Prell C. H. Quinn A. D. Reeves M. Seely R. Thomas M. J. van der Werff Ten Bosch P. Vergunst L. Wagner 《Land Degradation \u0026amp; Development》2013,24(4):307-322
It is increasingly recognised that land degradation monitoring and assessment can benefit from incorporating multiple sources of knowledge, using a variety of methods at different scales, including the perspectives of researchers, land managers and other stakeholders. However, the knowledge and methods required to achieve this are often dispersed across individuals and organisations at different levels and locations. Appropriate knowledge management mechanisms are therefore required to more efficiently harness these different sources of knowledge and facilitate their broader dissemination and application. This paper examines what knowledge is, how it is generated and explores how it may be stored, transferred and exchanged between knowledge producers and users before it is applied to monitor and assess land degradation at the local scale. It suggests that knowledge management can also benefit from the development of mechanisms that promote changes in understanding and efficient means of accessing and/or brokering knowledge. Broadly, these processes for knowledge management can (i) help identify and share good practices and build capacity for land degradation monitoring at different scales and in different contexts and (ii) create knowledge networks to share lessons learned and monitoring data among and between different stakeholders, scales and locations. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献