首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   91篇
  免费   6篇
林业   10篇
农学   11篇
  13篇
综合类   13篇
农作物   6篇
水产渔业   14篇
畜牧兽医   17篇
园艺   3篇
植物保护   10篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   4篇
  2019年   9篇
  2018年   4篇
  2017年   3篇
  2016年   7篇
  2015年   4篇
  2014年   4篇
  2013年   7篇
  2012年   7篇
  2011年   9篇
  2010年   4篇
  2009年   6篇
  2008年   4篇
  2007年   1篇
  2006年   5篇
  2005年   1篇
  2004年   1篇
  2003年   4篇
  2002年   1篇
  1998年   1篇
  1996年   2篇
  1991年   1篇
  1990年   2篇
  1986年   1篇
  1969年   1篇
排序方式: 共有97条查询结果,搜索用时 31 毫秒
21.
In northern Pakistan, many farming communities rely on domestic yak (Bos grunniens) as a principle source of income. A 2006 participatory disease surveillance report from this region indicated that foot-and-mouth disease (FMD) is the most prevalent annual disease of yak. Our objectives of this study were to determine exposure levels of yak to FMD virus; implement a vaccination program based on current, regional FMD virus serotypes and subtypes; and quantify immune responses following vaccination. Blood samples were used to determine pre-vaccination exposure of animals to FMD virus by antibody presence to non-structural proteins of FMD virus using a 3-ABC trapping indirect ELISA. Vaccine used consisted of FMD serotypes ‘O’ (PanAsia-2), ‘A’ (Iran-05), and ‘Asia-1’ (Shamir), but changed later during the study to match newly circulating viruses in the country (‘O’-PanAsia-2; ‘A’-Turk-06 and Asia-1-Sindh-08). Three hundred sixty-three blood samples were tested from selected villages to determine pre-vaccination FMD virus exposure in yak with an average of 37.7%. Immune responses from initial vaccination and booster dose 30 days later showed clear protective levels (as mean percent inhibition) of antibodies against structural proteins of serotypes ‘O,’ ‘A,’ and ‘Asia-1.’ These responses remained above threshold positive level even at day 210 following initial vaccination. Results of sero-surveillance and anecdotal information of repeated FMD outbreaks demonstrate the persistence of FMD virus of yak in northern Pakistan. Laboratory results and field observations clearly indicated that yak can be protected against FMD with a good quality vaccine with FMD serotype(s) matching current, regionally circulating FMD virus.  相似文献   
22.
Hyacinth bean (Lablab purpureus L.) serves as a good source of vegetable proteins in human diet. Its seeds and pods contain as much as 20–28% protein. Besides, it contains tyrosinase enzyme, which has potential use in the treatment of hypertension. Phosphorus deficiency causes a serious yield and quality constraint of beans at Aligarh, Western Uttar Pradesh, India. To address the problem, a pot experiment was conducted to study the effect of basal phosphorus application on the agricultural performance of this medicinal legume. The plants were grown in pots containing soil supplied with five levels of phosphorus viz. 0, 25, 50, 75 and 100 mg P kg−1 soil as potassium dihydrogen orthophosphate (KH2PO4). The growth and other physiological attributes, leaf nutrient contents, nodule-nitrogen and leghemoglobin content were studied at 60, 90 and 120 days after sowing (DAS), photosynthesis and other related parameters were measured at 90 DAS and yield and quality attributes were recorded at harvest (150 DAS). Nitrate reductase and carbonic anhydrate activities, leaf-N, -P, -K and -Ca contents and nodule-nitrogen and leghemoglobin contents reached the maximum extent at 60 DAS. At 90 and 120 DAS, the values decreased significantly. Chlorophyll content, carotenoids content, and photosynthesis were at maximum level at 90 DAS. At various growth stages, phosphorus application at 75 mg P kg−1 soil resulted in maximum amelioration of most of the parameters studied. It increased the seed-yield by 38.3%, seed-protein content by 14.9% and seed-carbohydrate content by 5.0%, relative to the control. It was concluded that there was a hidden hunger of hyacinth bean for phosphorus owing to soil-phosphorus deficiency that was ameliorated effectively by its basal dressing at 75 mg P kg−1 soil.  相似文献   
23.
24.
Tropical Animal Health and Production - Assessment of the ruminant livestock feed sources availability, existing feeding practices, and nutrient balances was embarked at different zones of Gurez...  相似文献   
25.
Bio-based CaCO3 powder was synthesized via size reduction method from waste eggshells. The XRD analysis revealed that eggshell powder consists of CaCO3 in calcite form. The inclusion level of CaCO3 contents were varied of 5, 10, 15, 20 and 25 wt.% of prepared CaCO3-polyester film. Effects of different proportions of prepared chicken eggshell and commercial CaCO3 filler on the polyester resin composites films were compared by means of mechanical and physical test. It was found that the addition of CaCO3 filler to the polyester films leads to improve the mechanical properties. The findings revealed that the best and optimum CaCO3 filler content was 10 wt.% and among the prepared polyester films, eggshell CaCO3-polyester films showed the best performance. The mechanical properties of CaCO3-polyester films were measured in terms of tensile strength, elongation-at-break, tensile modulus, flexural strength and impact strength. For eggshell CaCO3- polyester films, the maximum values of the aforementioned mechanical properties were 52.70 MPa, 4.63 %, 1868.70 MPa, 101.20 MPa and 8.40 kJ/m2, respectively, whereas for commercial CaCO3-polyester films those values were 48.12 MPa, 4.50 %, 1790.30 MPa, 97.50 MPa and 8.21 kJ/m2, respectively. Further, water absorption of the composite films as a function of time had also been investigated at 10 wt.% filler content.  相似文献   
26.
Cellular as well as humoral immune responses were detected in six rams experimentally infected with Brucella ovis. Specific antibodies were detectable by enzyme-linked immunosorbent assay by day 11 after infection in all the rams. The levels of IgM antibodies and total antibodies in the serum rose until 33 and 41 days after infection respectively, then levelled off. Antigen-induced blastogenic responses by lymphocytes developed as early as five days after infection in all rams but had decreased to low levels by day 63 in most. Blastogenesis induced by phytohaemagglutinin and concanavalin A varied among infected rams and did not differ significantly (P greater than 0.05) from control rams. All rams had developed delayed-type skin hypersensitivity by day 63 after infection. One ram which did not become infected as a result of exposure had low levels of B ovis serum antibodies and a detectable antigen-induced lymphocyte blastogenic response before infection, suggesting the involvement of cell-mediated immunity in protection against B ovis.  相似文献   
27.
Summary Pure cultures ofCorynebacterium pseudotuberculosis were obtained from 11 cases of lymphadenitis (known locally as taloa or mala) in camels. Camel isolates produced typical taloa in camels experimentally inoculated subcutaneously at the base of the external ear with 1010 colony forming units. A sheep strain ofC. pseudotuberculosis inoculated into camels produced a local abscess at the site of inoculation but did not produce taloa. Re-infection of camels recovered from experimental inoculation did not produce taloa suggesting the possibility of the development of a vaccine against lymphadenitis in camels.
Infeccion PorCorynebacterium Pseudotuberculosis Y Linfadenitis (Taloa O Mala) En El Camello
Resumen Se obtuvieron cultivos puros deCorynebacterium pseudotuberculosis a partir de 11 casos de linfadenitis (conocida localmente como taloa o mala) en camellos. La inoculación subcutánea en camellos en la base de la oreja de 1010 unidades formadoras de colonias procedentes de un cultivo obtenido de camellos infectados causó taola. Sin embargo, una cepa ovina deC. pseudotuberculosis causó un abceso en el lugar de la inoculación pero no produjo taola en camellos. La reinfección de los camellos que se habían recuperado de la inoculación experimental no causó taola, lo que sugiere la posibilidad de desarrollar una vacuna frente a la linfadenitis caseosa del camello.

Infection ACorynebacterium Pseudotuberculosis Et Lymphadenite (Taloa Ou Mala) Chez Le Chameau
Résumé On a obtenu des cultures pures deCorynebacterium pseudotuberculosis à partir de 11 cas de lymphadénite (dénommée localement taloa ou mala) chez des chameaux. L'inoculation expérimentale des isolements camelins faite en infection sous-cutanée à la base de l'oreille externe avec 1010 unités formant des colonies a provoqué un taloa typique. Une souche ovine deC. pseudotuberculosis inoculée à des chameaux n'a conduit qu'à la formation d'un abcès local au point d'inoculation mais pas au taloa. La réinfection des chameaux guéris d'une inoculation expérimentale ne provoque pas de taloa, ce qui permet d'augurer la possibilité de développement d'un vaccin contre la lymphadénite cameline.
  相似文献   
28.
29.
A wavelet analysis-based approach for damage localization in wood beams   总被引:2,自引:0,他引:2  
Free vibration testing was conducted to generate the first two mode shapes for damage detection in timbers. A wavelet transform was proposed to postprocess the mode shapes for damage pattern recognition. The wavelet used here was “db3.” The different damage severities, damage locations, and number of damaged areas were simulated by removing mass from intact beams. The results showed that the chosen wavelet db3 is suitable and that the wavelet coefficients are sufficiently sensitive to identify the existence of damage and its location in cases of different damage location, severity, and number. An edge distortion effect was apparent at the two computing edges where the wavelet coefficients were abnormally high. The wavelet coefficients showed dominant spikes around the damage locations and were zero everywhere else except the two computing edges. The dominant spikes coincided well with the damage location.  相似文献   
30.
In this presentation,we report on de novo and axillary shoot regeneration and rooting of shoots maintained over a long term,from cultures of Tectona grandis L.Shoot-tips of teak shoots forced from epicormic buds were used as the starting material for axenic shoot-culture establishment.Long term maintenance of such axenic shoot cultures was carried out by regular sub-culturing on MS media supplemented with N 6-benzyleadenine (BA,8.8 μmol L-1) and indole-3-butyric acid (IBA,2 μmol L-1) for 24 months.Vigorously growing shoot tips (2 3 cm long) were inoculated on the MS basal medium supplemented with different concentrations (0,1,2,4,6,8 or 10 μmol L-1) of either IBA or α-naphthaleneacetic acid (NAA) for rooting.Axillary and de novo shoots were developed from axillary and cut basal ends of shoots,respectively.Shoots growing on auxins were further sub-cultured (every 15 days) and maintained for 45 days.The greatest number of de novo (5.06) as well as axillary shoots (2.85) was observed on the MS medium supplemented with 10 μmol L-1 NAA or 8 μmol L-1 IBA,respectively,after 45 days.The combinations of both IBA (μmol L-1) + NAA (μmol L-1) were tested at different concentrations (4 + 4,6 + 6,8 + 8) supplemented to a half strength MS basal medium with 0.1% activated charcoal for rooting of decapitated and non-decapitated de novo and axillary shoots.Rooting from non-decapitated de novo shoots was highest (93.33%) with a mean number of roots of 4.61 on this medium,supplemented with 6 μmol L-1 IBA + 6 μmol L-1 NAA,after 36 days of initial culture.Individual auxin,however,was not effective for root induction.Rooted shoots were acclimatized in a green house and after four weeks plantlets were transferred to the field.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号