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   48篇
  免费   1篇
农学   4篇
基础科学   3篇
  12篇
综合类   6篇
农作物   2篇
畜牧兽医   21篇
植物保护   1篇
  2020年   1篇
  2018年   1篇
  2014年   3篇
  2013年   3篇
  2012年   1篇
  2011年   2篇
  2009年   1篇
  2008年   2篇
  2006年   1篇
  2005年   2篇
  2002年   1篇
  1999年   1篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1991年   1篇
  1988年   1篇
  1985年   2篇
  1984年   2篇
  1982年   2篇
  1981年   1篇
  1980年   3篇
  1979年   1篇
  1978年   1篇
  1977年   2篇
  1976年   1篇
  1974年   2篇
  1972年   1篇
  1970年   1篇
  1969年   1篇
  1967年   2篇
  1963年   1篇
  1931年   1篇
排序方式: 共有49条查询结果,搜索用时 15 毫秒
1.
2.
Among the 57 monoclonal antibodies (mAb) analyzed within the T-cell group from the Second Swine CD Workshop, six mAb fell within clusters T10 and T11 (No. 088, STH164; No. 148, FY1A3; No. 149, FY2C1; No. 150, FY1H2; No. 151, FY2A11; No. 169, BB23-8E6). The mAb within these two groups gave a similar appearance on flow cytometry and stained all peripheral blood T-cells as defined by CD4 and wCD8 staining. All six mAb precipitated a 24 kDa protein. On the basis of inhibition analyses performed as part of the workshop and from published data, the mAb define at least three epitopes. There is only minimal stimulation of resting peripheral lymphocytes, but four of the mAb produce strong stimulation in the presence of PMA. With the exception of STH164, all have been shown to react with CD3-transfected COS cells. The new mAb, therefore, react with three epitopes on porcine CD3 designated CD3a (BB23-8E6, FY2A11), CD3b (FY1A3, FY2C1), and CD3c (FY1H2). mAb STH164 appears to be reactive with another epitope, however, since its reactivity with CD3 has not been confirmed it is designated as wCD3.  相似文献   
3.
Using a kinetic turbidimetric assay based on the binding of serum glycoprotein to concanavalin A the acute phase reaction has been detected in dogs. Raised levels of glycoprotein were found in dogs which had undergone surgery, had been treated with bacterial endotoxin and had various inflammatory conditions.  相似文献   
4.
Little information exists concerning how crops will respond to the predicted increased night temperatures. The objective of this work was to determine if respiration and growth of sorghum [Sorghum bicolor (L.) Moench], a C, plant, and sunflower (Helianthus annuus L.), a C3 plant, are affected when the night temperature is increased by 5°C compared to the long-term (19 year) average night temperature in June in Kansas. Sorghum and sunflower were grown in two walk-in growth chambers with either the ambient night temperature (21C) or a high night temperature (26C). Day temperature was the same for all plants (27C). Both sunflower and sorghum had higher respiration rates under the elevated night temperature than under the ambient temperature. The average respiration rate of sunflower grown under elevated night temperature increased by 19% (0.89 vs. 0.75 μmol m?2 s?1) and that of sorghum by 44 % (0.52 vs. 0.36μmol m?2s?1). After 74 days, sunflower plants grown under the ambient night temperature were 30.2 cm taller than sunflower plants grown under the elevated night temperature; sorghum plants under the ambient temperature were 24.8 cm taller. Sunflower plants grown under the elevated night temperature formed flowers one week earlier than those grown under the ambient temperature. Sorghum formed no flowers by 74 days. Results suggest that, if climate change does increase night temperature, respiration will be increased more in C4, than C3 plants.  相似文献   
5.
Tomato plants (Lycopersicum esculentum Mill, ‘Red Cherry Small’), grown in 15 cm diameter plastic pots with a standard greenhouse medium (1:1:1, by volume, soil:peat:sand) were irrigated for 15 weeks with liquid sewage sludge containing a liquid cationic conditioner (Petroset SB, Phillips Petroleum Company, Bartlesville, Oklahoma) to determine the effect of the conditioner on Cd and Zn availability. Half of the plants received 50 ml week?1 liquid digested sludge with no conditioner and half of the plants received 50 ml week?1 sludge containing 0.25 ml conditioner (200:1, by volume, sludge:conditioner). Plant height was measured weekly. Plants were harvested 3, 6, 9, 12, and 15 weeks after sludge treatments began and separated into roots, shoots, and fruits for dry weight determination and Cd and Zn analyses. Soil and sludge crusts were sampled at the same times and analyzed for extractable concentrations of Cd and Zn. Dry weights of plants grown with conditioned sludge were similar to those grown with nonconditioned sludge. Plants with conditioner flowered and fruited one and two weeks earlier, respectively, than plants without conditioned. Six weeks after treatments began, when the plants had grown to their greatest height, Cd concentrations in sludge crusts, soil, and roots receiving conditioner were 2.0, 1.5, and 2.1 times greater, respectively, than crusts, soil and roots not receiving conditioner. After the six weeks sampling time, Cd concentrations in crusts, soil, and roots receiving conditioned sludge were similar to those in crusts, soil, and roots receiving nonconditioned sludge. At the third-week sampling time, shoots of plants grown with conditioner had 2.6 times more Cd than shoots of plants grown without conditioner. Cadmium concentrations in shoots from both treatments were similar at later sampling dates. Cadmium content of fruits was the same for both treatments all sampling times. Zinc content of roots, shoots, fruits soil, and sludge crusts was no affected by the conditioner. Results showed that a cationic conditioner, added to sludge, increased the availability of Cd, but not of zn, for tomato plants until maximum height was reached.  相似文献   
6.
Two varieties of winter wheat (Triticum aestivum L. em. Thell. ‘Ponca’ and ‘KanKing’), one considered drought sensitive (‘Ponca’) and one considered drought resistant (‘KanKing’), were grown from seed in pots of soil placed in wind or still air for 36 days to determine the effect of wind on water potentials, turgor pressure, and stomatal resistance of leaves. During the experiment, plants were well watered and soil was moist. In wind and still air, water potentials and turgor pressures of the drought sensitive wheat were higher, and stomatal resistances were lower, than those of the drought resistant wheat. Plants grown in wind had lower turgor pressures than plants grown in still air.The results showed that wind reduced turgor pressure and that measurements of water potential, turgor pressure, and stomatal resistance could be used to select varieties for windy areas.  相似文献   
7.
8.
Neoplasms of Equidae   总被引:7,自引:0,他引:7  
In a retrospective study of neoplasms in Equidae pre;ented to the Animal Disease Diagnostic Laboratory, Purdue University, from Jan 1, 1970, to Dec 31, 1974, data were compiled on numbers and anatomic sites of neoplasms as well as on age, sex, and breed of subjects from which the neoplasms were taken. During this 5-year period, 21 neoplasms were diagnosed from 687 equine necropsies (3.1%) and 215 from 635 biopsies (33.9%), totaling 236 neoplasms from 1,322 cases (17.9%). The most common neoplasms were sarcoids (43.6%) and squamous cell carcinomas (24.6%). Papillomas (5.5%), nerve sheath tumors (4.2%), melanomas (3.8%), lipomas (3.0%), granulosa cell tumors (2.5%), fibromas (2.1%), cholesteatomas (1.3%), and lymphosarcomas (1.3%) were less common.  相似文献   
9.
The technique of enhancing species diversity by spreading species‐rich green hay following turf scarification was tested in a semi‐improved meadow site in Cumbria, UK. Botanical assessments were carried out in May 2008 (prior to treatment), May and October 2009, and May 2010. Both total species‐richness (number of species per m2) and the richness and aggregate cover of positive indicator species were enhanced by hay spreading, with an average of 21·8 species per m2 compared with 17·0–18·7 species per m2 for other treatments by May 2010. Significant increases in all three variables occurred by May 2009, with even greater increases between this assessment and May 2010. Hay spreading introduced seven new species, most of which subsequently increased over time, and enhanced the frequency of a further seven. All these species together accounted for only about 5% of vegetation cover in 2010, but the level of species‐richness achieved was equivalent to that of good quality semi‐improved grassland and also equivalent to that achieved in studies where the technique was developed. Results are discussed in detail in relation to the seeding phenology of species at the donor site, as are other factors affecting the technique's potential and possible means of enhancing it.  相似文献   
10.
Finger millet [Eleusine coracana (L.) Gaertn.] is an important coarse cereal crop grown in the arid and semi‐arid regions and often experiences high temperature (HT) stress. The objectives of this research were (i) to quantify effects of season‐long HT stress on physiological and yield traits, (ii) to identify the developmental stages most sensitive to HT stress and (iii) to quantify the genetic variability for HT stress tolerance in finger millet. Research was conducted in controlled environment conditions. HT stress decreased the chlorophyll index, photosystem II activity, grain yield and harvest index. Maximum decrease in number of seeds per panicle and grain yield per plant was observed when stress was imposed during booting, panicle emergence or flowering stages. Maximum genotypic variation was explained by panicle width and number of seeds per panicle at optimum temperature (OT) and grain yield per plant at HT and number of seeds at HT. Based on the stress response and grain yield, tolerant or susceptible genotypes were identified. Finger millet is sensitive to HT stress during reproductive stages, and there was genotypic variability among the finger millet genotypes for number of seeds per panicle and grain yield under HT, which can be exploited to enhance stress tolerance.  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