全文获取类型
收费全文 | 139篇 |
免费 | 2篇 |
专业分类
林业 | 7篇 |
农学 | 10篇 |
19篇 | |
综合类 | 17篇 |
农作物 | 10篇 |
水产渔业 | 36篇 |
畜牧兽医 | 18篇 |
园艺 | 5篇 |
植物保护 | 19篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 1篇 |
2013年 | 13篇 |
2012年 | 3篇 |
2011年 | 8篇 |
2010年 | 9篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 13篇 |
2004年 | 1篇 |
2003年 | 8篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1977年 | 1篇 |
1969年 | 2篇 |
1968年 | 3篇 |
1966年 | 1篇 |
排序方式: 共有141条查询结果,搜索用时 31 毫秒
61.
Kavitha Ramadass MSc Subramanian Palaniyandi 《Archives of Agronomy and Soil Science》2013,59(5):497-506
Abstract A study was conducted in the Department of Environmental Sciences, Tamil Nadu Agricultural University, Coimbatore, India, to transform the normal compost into bioactive compost, which has multiple benefits to the crop system. The key players in this transformation process were Azotobacter sp., Pseudomonas sp., Phosphobacteria sp. and the waste materials like poultry litter and spent wash. This enrichment process increases both the quality and nutrient content of the municipal solid waste compost significantly. A study was carried out to evaluate the effect of application of different levels of enriched municipal solid waste compost on the availability of the macronutrient content to the rice field soil. The effect of enriched compost on soil available nutrients was significant. The soil ammonium nitrogen and soil nitrate nitrogen content was found to be high in the plots where the enriched compost was applied along with inorganic fertilizer with the values of 38.87 mg kg?1 and 32.87 mg kg?1, respectively. In addition, the availability decreased towards crop growth. The soil available P and K were also increased with enriched compost application to about 22.46 kg ha?1 and 647 kg ha?1 compared with control values of 19.44 kg ha?1 and 518 kg ha?1, respectively. Both phosphorus and potassium content decreased towards advancement of crop growth. 相似文献
62.
63.
The influence of Tribulus terrestris on the activities of testicular enzyme in Poecilia latipinna was assessed in lieu of reproductive manipulation. Different concentrations of (100, 150, 200, 250, and 300 mg) Tribulus terrestris extract and of a control were tested for testicular activity of enzymes in Poecilia latipinna for 2 months. The testis and liver were homogenized separately in 0.1 mol/l potassium phosphate buffer (0.1 mol/l, pH 7.2).
The crude homogenate was centrifuged, and supernatant obtained was used as an enzyme extract for determination of activities.
The activities of testicular functional enzyme ALP, ACP, SDH, LDH, and G6PDH levels were changed to different extent in treated
groups compared with that of the control. The total body weight and testis weight were increased with the Tribulus terrestris-treated fish (Poecilia latipinna). These results suggest that Tribulus terrestris induced the testicular enzyme activity that may aid in the male reproductive functions. It is discernible from the present
study that Tribulus terrestris has the inducing effect on reproductive system of Poecilia latipinna. 相似文献
64.
R. Kirubagaran B. Senthilkumaran C. C. Sudhakumari K. P. Joy 《Fish physiology and biochemistry》2005,31(2-3):183-188
In the present investigation, significant annual/seasonal variations were noticed in plasma and pituitary gonadotropin (GTH)
which were correlated with gonado-somatic index, plasma estradiol-17β, and nuclear E2 receptor (NE2R) in the pituitary, hypothalamus and telencephalon. The NE2R concentrations and dissociation constant (k
d) values showed significant seasonal variations with high values in the late preparatory phase and low values in the postspawning
phase. The NE2R levels were the highest in the pituitary, followed by the hypothalamus and telencephalon in all the seasons. In the prespawning
phase, ovariectomy (OVX) elicited a strong negative feedback on GTH secretion with a bimodal pattern of release and elevated
the NE2R levels and k
d values, without producing any significant change in the resting phase suggesting that E2 appears to exert differential feedbacks on GTH secretion. 相似文献
65.
66.
Administration of Methallibure, a non-steroidal gonadotropin (GTH) inhibitor 20 g g–1 body weight; i.p., daily for 10 days, to prespawning phase female Heteropneustes fossilis inhibited the brain-pituitary-ovarian axis as indicated by significant reductions in plasma and pituitary levels of GTH-II, and plasma levels of 17-estradiol (E2) and testosterone. Concurrently, the treatment resulted in significant reductions in the hypothalamic content of serotonin, noradrenaline (and adrenaline) that stimulate, and a significant elevation of dopamine that inhibits GTH-II release in this species. Activities of the monoamine degrading enzymes, monoamine oxidase and catechol-O-methyltransferase were significantly increased, while that of the synthesizing enzymes, dopamine--hydroxylase and phenylethanolamine-N-methyltransferase were significantly decreased. These results suggest that the mechanism of inhibition of GTH-II secretion includes, among others, differential actions of the drug on hypothalamic monoamine metabolism. 相似文献
67.
Huang JY Zhong L Wang CM Sullivan JP Xu W Zhang LQ Mao SX Hudak NS Liu XH Subramanian A Fan H Qi L Kushima A Li J 《Science (New York, N.Y.)》2010,330(6010):1515-1520
We report the creation of a nanoscale electrochemical device inside a transmission electron microscope--consisting of a single tin dioxide (SnO(2)) nanowire anode, an ionic liquid electrolyte, and a bulk lithium cobalt dioxide (LiCoO(2)) cathode--and the in situ observation of the lithiation of the SnO(2) nanowire during electrochemical charging. Upon charging, a reaction front propagated progressively along the nanowire, causing the nanowire to swell, elongate, and spiral. The reaction front is a "Medusa zone" containing a high density of mobile dislocations, which are continuously nucleated and absorbed at the moving front. This dislocation cloud indicates large in-plane misfit stresses and is a structural precursor to electrochemically driven solid-state amorphization. Because lithiation-induced volume expansion, plasticity, and pulverization of electrode materials are the major mechanical effects that plague the performance and lifetime of high-capacity anodes in lithium-ion batteries, our observations provide important mechanistic insight for the design of advanced batteries. 相似文献
68.
Subramanian Velmurugan Stanly Mary Josephine Punitha Mariavincent Michael Babu Thangaswamy Selvaraj 《Journal Of Applied Aquaculture》2013,25(3):230-239
Herbs with known antibacterial characteristics were chosen and extracted with different polar and non-polar solvents and screened against five different shrimp pathogens: Pseudomonas aeruginosa, Staphylococcus aureus, Aeromonas hydrophila, Vibrio harveyi, and V. parahaemolyticus. Five different diets were prepared by incorporating equal proportions of these five herbal extracts at increasing concentrations: Control (0), HD1 (200), HD2 (400), HD3 (600), and HD4 (800 mg/kg of diet). Diets were individually fed to the Penaeus monodon post larvae (PL 25) for 30 days. At 10-day intervals, post larvae were bath challenged with V. harveyi and observed for pathological signs. Post larvae fed the HD 4 diet enjoyed a 75% improvement in survival over the control group and significantly improved final weights and SGR (P < 0.05). The herbal diets HD1 to HD4 helped to decrease the Vibrio load in P. monodon post-larvae after challenging. 相似文献
69.
The effect of ambient salinity on the haemolymph variables of Fenneropenaeus indicus and its susceptibility to Vibrio harveyi infection under salinity stress has been studied. Adult shrimps were acclimated to 5‰ (hypo osmotic), 25‰ (iso osmotic) and 35‰ (hyper osmotic) salinity levels and the animals were injected with a mid logarithmic culture of V. harveyi at sub lethal level and haemolymph parameters were analysed. Haemolymph proteins, intracellular superoxide anion production, phenoloxidase (PO), alkaline phosphatase (ALP) and acid phosphatase (ACP) activity were found to be at elevated level both at 5‰ and 35‰ post challenge. The haematological responses showed a progressive increase (P < 0.05) up to post challenge day 5 (PCD 5) followed by a considerable decline at all salinities with the lowest being at 35‰. The alterations in the variables were higher in shrimps held at 5‰. However, the V. harveyi infection was severe in animals held at 35‰. The reduction in the parameters could be correlated with the decrease in survival rate of shrimps at 35‰ with a concurrent increase in V. harveyi at this salinity. Multiple regression analysis revealed that ACP (P < 0.001), haemocyte protein HCP (P < 0.001) and PO (P < 0.05) could explain 91% variability in the shrimp survival. These parameters may be used as effective shrimp health indicators. It is evident from the study that ambient salinity alters the haemolymph variables, modulates the virulence in V. harveyi and makes the shrimps more vulnerable to infection at higher salinity. The virulence of V. harveyi is increased at 35‰ salinity as being evidenced from the high mortality at this salinity. The study emphasizes the importance of salinity as an important environmental factor both in terms of host susceptibility and virulence of the pathogen. 相似文献
70.
Success of a baculovirus in the field depends on the selection and utilization of effective isolates of viruses with increased
pathogenicity and virulence. Isolates ofPlutella xylostella granuloviruses collected from Kenya and India were compared for genetic variations by restriction endonuclease enzyme analysis
and for biological activity based on their median lethal concentration and time-to-kill early- and late-third instars. TheP. xylostella granulovirus isolates in Kenya were more diverse than those in India and were considerably different from the latter, with
only 53–61% similarity. The Kenyan and Indian isolates did not differ significantly for their median lethal concentration,
but the Kenyan isolate collected from Kibwezi was significantly faster than other isolates in killing early- and late-third
instarP. xylostella. Cluster analysis of restriction fragment marker profiles of theP. xylostella granulovirus with other granuloviruses revealed that it grouped into a cluster with Spodoptera litura granulovirus, whereasHelicoverpa armigera andChilo infuscatellus granuloviruses grouped into another cluster. Results of the present study indicate the existence of genetically and biologically
diverse isolates ofP. xylostella granulovirus which could be further developed into effective biopesticides for the management of diamondback moth.
http://www.phytoparasitica.org posting May 21, 2008. 相似文献