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   86篇
  免费   5篇
林业   8篇
农学   1篇
  15篇
综合类   3篇
农作物   6篇
水产渔业   9篇
畜牧兽医   40篇
园艺   2篇
植物保护   7篇
  2024年   1篇
  2023年   3篇
  2022年   3篇
  2021年   4篇
  2020年   4篇
  2019年   5篇
  2018年   3篇
  2017年   5篇
  2016年   8篇
  2015年   2篇
  2014年   6篇
  2013年   6篇
  2012年   10篇
  2011年   12篇
  2010年   6篇
  2008年   1篇
  2007年   2篇
  2006年   3篇
  2005年   1篇
  2004年   2篇
  2003年   2篇
  1979年   1篇
  1978年   1篇
排序方式: 共有91条查询结果,搜索用时 31 毫秒
31.
This work was performed to determine the predatory capacity in vitro of the nematophagous fungus Duddingtonia flagrans (isolate AC001) on cyathostomin infective larvae of horse (L3). The experimental assay was carried out on plates with 2% water-agar (2% WA). In the treated group, each plate contained 1.000 L3 and 1.000 conidia of the fungus. The control group without fungus only contained 1.000 L3 in the plates. Ten random fields (4 mm diameter) were examined per plate of treated and control groups, every 24 h for seven days under an optical microscope (10× and 40× objective lens) for non-predated L3 counts. After 7 days, the non-predated L3 were recovered from the Petri dishes using the Baermann method. The interaction there was a significant reduction (p < 0.01) of 93.64% in the cyathostomin L3 recovered. The results showed that the D. flagrans is a potential candidate to the biological control of horse cyathostomin L3.  相似文献   
32.
Toxocara (Neoascaris) vitulorum is a gastrointestinal nematode parasite of young ruminants, responsible for high mortality rates in parasitized cattle and buffalo calves. The objective of this work was to compare the predatory capacity under laboratory conditions of four fungal isolates of the nematophagous fungus Pochonia chlamydosporia (VC1, VC4, VC5 and VC12) on T. vitulorum eggs in 2% water-agar (2% WA). T. vitulorum eggs were plated on 2% WA Petri dishes which contained cultured fungal isolates and control plates without fungi. After 10 and 15 days one hundred eggs were removed and classified according to the following parameters: type 1, biochemical and physiological effect without morphological damage to the eggshell, type 2, lytic effect with morphological alteration of the eggshell and embryo and type 3, lytic effect with morphological alteration of eggshell and embryo in addition to hyphal penetration and internal egg colonization. The fungal isolates were effective in the destruction of T. vitulorum eggs presenting the type 3 effect at 10 and 15 days after contact with the fungus. No nematophagous fungi were observed in the control group during the experiment. There was no variation in the predatory capacity of the fungal isolates (P?>?0.01) at the intervals of 10 and 15 days. These results indicate that P. chlamydosporia (VC1, VC4, VC5 and VC12) negatively influenced the development of T. vitulorum eggs and can be considered a potential candidate for the biological control of nematodes.  相似文献   
33.
34.
A 14‐year‐old, female, captive‐born orangutan (Pongo pygmaeus) developed bilateral cataracts. Ultrasonography, electroretinography and cataract correction using phacoemulsification were performed bilaterally. This case report aims to describe the ophthalmic procedures performed in this animal critically endangered of extinction. The surgery successfully restored vision and normal activity to the patient.  相似文献   
35.
Rog B. Parsons 《Geoderma》1978,21(1):25-39
The development and distribution of soils in the Coast Range and Klamath Mountains are related to geomorphic surfaces and slope gradients. Soils over basalt, studied in the Coast Range, were formed in transported materials and include examples of more than a half dozen great groups of the Alfisol, Inceptisol, Mollisol, and Ultisol orders. Distribution patterns of the soils can be related to active slopes, metastable slopes, pediments, ridge tops, flood plains, and alluvial fans. Variables among the factors of soil formation in the Coast Range are chiefly geomorphic surfaces and parent materials.Soils of a lithosequence of pyroclastics, granite and schist in the Klamath Mountains include examples of great groups in the Entisol, Inceptisol, and Mollisol orders. All soils from pyroclastics have argillic horizons, those from granite lack argillic horizons, and those from schist lack argillic horizons except on relatively stable surfaces. Average thicknesses of soils over saprolite range from 76 cm over granite and schist to 150 cm over pyroclastics.Lithologic discontinuities are common in both mountain areas. Field techniques for identification, described briefly, include stone lines, irregular distribution of rock fragments with depth, thicknesses of weathering rinds on rock fragments, and the lateral extensions of soil horizons.  相似文献   
36.
37.
Biological control of gastrointestinal nematodiasis in ruminants is an alternative to reduce the number of infective larvae. The fungal isolates predatory activity preservation is a basic requirement for the success of this control type. The aim of this work is to evaluate the predatory capacity of the fungus Arthrobotrys robusta (isolate I-31), preserved on silica gel on infective larvae of Haemonchus contortus under laboratory conditions on 2 % water agar (2 % WA). In this essay, A. robusta storage on silica gel showed successful predatory activity on H. contortus L3 larvae (p?<?0.01) compared to the control group. Nematophagous fungi were not observed in the control group during the experiment. There was a significant reduction (p?<?0.01) of 73.84 % in the means of H. contortus (L3) recovered from treatment with isolate I-31 compared to the control without fungi. Results indicate that A. robusta (I-31) could survive stored on silica gel for at least 7 years and keep its predatory activity on H. contortus (L3).  相似文献   
38.
This report describes the first case of idiopathic hypertrophic osteopathy (HO) in a cat. No causes for the bone pathology were found following evaluation of the physical and laboratory examinations (complete blood count, albumin, creatinine, urea, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase and gamma-glutamyltransferase and urinalysis), and after histopathological evaluation of organs at necropsy. Based on the radiographic, clinical and anatomopathological findings, idiopathic HO was diagnosed.  相似文献   
39.
A total of 910 maritime pine (Pinus pinaster Aiton) wood discs, belonging to a genetic trial of 80 families with 11–12 trees per family, were used in this study. A near infrared (NIR) partial least squares regression (PLSR) model for the prediction of Kappa number of Pinus pinaster Aiton pulps obtained from samples pulped under identical conditions was calculated. Very good correlations between NIR spectra of maritime pine pulps and Kappa numbers in the range from 58 to 100 were obtained. Besides the raw spectra, spectra pre-processed with ten methods were used for PLS analysis (cross validation with 57 samples), showing that even after test set validation (with 34 samples) no model decision could be made due to almost identical statistics. The final evaluation that proved the predictive power of the models by predicting pulps with unknown Kappa numbers allowed choosing a model according to a minimal number of outliers found during this process. The minimum–maximum normalized spectra in the wave number range from 6,110 to 5,440 cm−1 used for the calculation gave the best model with a root mean square error of prediction of 2.3 units of Kappa number, a coefficient of determination of 95.9%, and one PLS component. The percentage of outliers during evaluation was 0.9%.  相似文献   
40.
Viability and in vitro and in vivo activities of freeze-dried conidia of the predatory fungus Arthrobotrys robusta (I-31) were evaluated against infective larvae (L(3)) of Ancylostoma spp. in dogs. A. robusta conidia were lyophilized and stored at 4°C for a month. Freeze-dried conidia were diluted to 1×10(3)conidia/ml and tested in vivo. The treated group consisted of a solution containing conidia (1ml) and 1000 Ancylostoma spp. (L(3)) placed on Petri dishes plated with 2% water-agar (2% WA), at 25°C, in the dark for 10 days. The control group consisted of 1000 Ancylostoma spp. L(3), plated on 2% WA. After 10 days, Ancylostoma spp. L(3) from both the treated and the control groups were recovered and counted. The in vivo test was performed on two dogs by administering a single oral dose of freeze-dried conidia (1.5×10(5)) in aqueous solution to one animal and only water to the other. Fecal samples were collected at 12, 24 and 48h after the treatments, plated 2% WA plates and incubated at 25°C for 15 days. A thousand Ancylostoma spp. L(3) larvae were spread on these plates. At day 15, infective L(3) recovered from the treated and control groups were counted. In the in vitro test, A. robusta was able to survive the freeze-drying process, grow in the plates, form traps and capture Ancylostoma spp. L(3). There was a 75.38% decrease in the number of infective larvae recovered from the treated group. The in vivo test showed that freeze-dried A. robusta conidia survived the passage through the gastrointestinal tract of the treated dog, was able to grow in the plates and capture Ancylostoma spp. L(3), reducing the number of recovered L(3) (p<0.01). Freeze-drying can be an alternative method for conservation of conidia of nematophagous fungi.  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