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   137篇
  免费   16篇
林业   15篇
农学   11篇
  34篇
综合类   3篇
农作物   14篇
水产渔业   12篇
畜牧兽医   37篇
园艺   4篇
植物保护   23篇
  2024年   2篇
  2023年   3篇
  2022年   3篇
  2021年   3篇
  2020年   2篇
  2019年   3篇
  2018年   6篇
  2017年   8篇
  2016年   14篇
  2015年   10篇
  2014年   3篇
  2013年   12篇
  2012年   3篇
  2011年   9篇
  2010年   9篇
  2009年   6篇
  2008年   5篇
  2007年   1篇
  2006年   6篇
  2005年   3篇
  2004年   6篇
  2003年   3篇
  2002年   5篇
  2001年   2篇
  2000年   2篇
  1999年   2篇
  1998年   1篇
  1996年   1篇
  1995年   2篇
  1993年   1篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1984年   2篇
  1983年   4篇
  1982年   1篇
  1981年   1篇
  1977年   1篇
  1971年   1篇
排序方式: 共有153条查询结果,搜索用时 15 毫秒
81.
Clitoria ternatea roots methanol extract when given by oral route to rats was found to inhibit both the rat paw oedema caused by carrageenin and vascular permeability induced by acetic acid in rats. Moreover, the extract exhibited a significant inhibition in yeast-induced pyrexia in rats. In the acetic acid-induced writhing response, the extract markedly reduced the number of writhings at doses of 200 and 400 mg/kg (p.o.) in mice.  相似文献   
82.
A novel in vitro flow through technique was developed and evaluated for immunodiagnosis of cystic echinococcosis in sheep using hydatid specific non-cross reactive 8-kDa protein. The 8-kDa protein was prepared from hydatid cyst fluid by DEAE-Sepharose fast flow anion exchange chromatography. In this flow through technique, the 8-kDa antigen was coated on the nitrocellulose membrane of flow through device. Protein A colloidal gold was used as detector. The evaluation of the technique was performed by comparing 150 known positive hydatid serum and known negative serum collected from sheep. The test was shown to be high sensitivity and specificity that were closely correlated with those of EITB. Furthermore the immunofiltration-based assay is rapid (2 min) and easy to perform with no requirement of special skill, reagent and instrumentation. This suggests the flow through technique is an acceptance alternative to be used in clinical laboratories lacking specialized equipments as well as large scale screening of cystic echinococcosis both in the field with animal and human populations.  相似文献   
83.
Genetic Resources and Crop Evolution - An atypical morphotype of pea (Pisum sativum L.) was identified during the germplasm characterization programme at the Indian Council of Agricultural...  相似文献   
84.
ABSTRACT

Cellulose nanocrystals have emerged as replacements for man-made fibers to fabricate environmentally friendly green products. In this work, cellulose nanocrystals (CNCs) of mixed morphology were synthesized by acid hydrolysis of compost using sulfuric acid. Compost, an agro-based biomass feedstock, procured from water hyacinth (Eichhornia crassipes), cow dung, and saw dust (8:1:1) was utilized for the extraction of cellulose, followed by synthesis of CNCs. Compost was prepared using a rotary drum composter and was utilized for the production of CNCs. A two-step procedure for the extraction of CNCs was studied. Initial chemical treatments, including alkali treatment and bleaching, led to the gradual removal of lignin and hemicellulose, while the subsequent sulphuric acid (40%) hydrolysis step yields CNCs in an aqueous suspension. The synthesized CNCs have been studied by Fourier transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and particle size analyzer. The morphology and dimension of nanofibrils were studied by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) techniques, which showed mixed morphology of rectangular cone type and spherical dimensions. Fabrication of such mixed morphology was found to be dependent on the selected biomass. The trace of metal elements present in the biomass was investigated by scanning electron microscopy-energy dispersive X-ray (SEM-EDX). We report a cost effective and feasible approach of utilizing inexpensive bioresources for production of value added products like CNCs, which could find potential application in the fields of healthcare, biomedical engineering, packaging, etc.  相似文献   
85.
Seventy edible wild forest green leafy vegetables (GLV) collected andconsumed by tribals of Andhra Pradesh, India were analyzed for totalcarotenoids (TC) and beta carotene (BC) contents using high performanceliquid chromatography (HPLC). The vitamin A activity expressed as retinolequivalents (RE) was calculated based on in vivo conversion factorgiven by WHO. The results of the study indicated that thirty-six GLV werefound to have high vitamin A activity (0.87 to 2.34 RE) with TC and BCcontents ranging from 12.22 to 36.13 and 5.21 to 14.05 mg %,respectively; thirty GLV had moderate vitamin A activity (0.36–0.8 RE)with TC and BC contents ranging from 10.60 to 31.33 and 2.19 to 4.78 mg %.Four GLV contained low vitamin A activity (0.07–0.32 RE); – TC and BCcontents ranging from 5.12 to 13.13 and 0.40 to 1.94, respectively. Thepercent beta carotene in total carotenoids among the three groups of theGLV varied from 19.41 to 73.02, 11.11 to 46.21 and 5.98 to 37.11,respectively.  相似文献   
86.
Mahsuri a popular traditional variety and the first rain-fed mega variety of the Indian sub- continent. It is highly susceptible to bacterial leaf blight caused by Xanthomonas oryzae pv.oryzae. Nine best performing families of Mahsuri pyramid containing four bacterial blight resistance genes (Xa4, xa5, xa13 and Xa21) were evaluated for agronomic, yield and its related characters viz. days to 50% flowering, plant height, number of tillers, panicle length, filled grains per panicle, grain weight, and yield under natural and disease pressure conditions for three consecutive wet seasons. In addition these pyramids were also evaluated for three different spacings to find out the optimum spacing under disease free and disease pressure conditions. Results revealed that under disease free conditions there was no significant difference between the pyramids and the parent for the characters evaluated in each spacing. However characters plant height, number of tillers, panicle length, filled grains per panicle, yield per plant and yield per sq. m. showed significant variation between the different spacings across seasons. Under heavy disease pressure the parent exhibited highly susceptible reaction whereas the pyramid families were highly resistant. A wider spacing had less yield loss when compared to dense planting under BB infestation in case of parent. There was no such yield loss in the pyramid families. When yield per sq. m. was taken into consideration the 20 × 20 cm spacing showed the highest yield when compared to the other two spacings since number of plants were more. The pyramids insulated the yield loss against bacterial leaf blight and are a gain to the farmers to help overcome the heavy yield losses due to this disease. These pyramids have the potential to replace the parent and can be used directly. In addition they can be used as donors for bacterial blight resistance in any breeding program.  相似文献   
87.
We investigated the plant population structure and the phy-tosociological and regeneration status in two disturbed tropical forests in Assam Province, the Hojai Reserve Forest and Kumorakata Reserve Fo...  相似文献   
88.
Experiments were conducted with the freshwater fish Macrognathus aculeatum to study the toxicity and metabolism of endosulfan and the effect of the pesticide on the oxygen consumption and total nitrogen excretion. The 96-hr LC50 value was 3.5 ± 0.2 ppb. In brain, gills, gut, liver, and kidney, endosulfan was metabolized to endosulfan sulfate, but this appears to be only an intermediary step as the nontoxic endosulfan ether was found only in the liver and kidney, the principal organs of elimination of toxicants in fish. The pesticide, both at sublethal and lethal concentrations, decreased oxygen consumption and total nitrogen excretion.  相似文献   
89.
A laboratory experiment was conducted to study the changes in inorganic and organic forms of nitrogen (N) in a Typic Haplustept soil treated with mustard cake vis-à-vis humic acid in the presence and absence of inorganic N. Results revealed that irrespective of treatments, significantly higher amount of soluble nitrate (NO3-), hydrolysable ammonium (NH4+), non-hydrolysable and total N were accumulated in the soil treated with mustard cake in the presence of inorganic N. However, on the other hand, a humic acid-treated system showed significantly higher content of exchangeable NH4+ and hexosamine N. Application of humic acid alone leads to the accumulation of a significantly higher amount of total hydrolysable and unidentified N in the soil. Among the different treatments, NH4+ fixation was more in mustard cake followed by humic acid-treated soil. Humic acid is more susceptible to mineralization than mustard cake, particularly with respect to total N accumulation in soils.  相似文献   
90.
The efficacy of three commercial formulations of strobilurins, viz., trifloxystrobin, kresoxim-methyl, and azoxystrobin was evaluated against sunflower downy mildew disease caused by Plasmopara halstedii under laboratory, greenhouse, and field conditions. Complete inhibition of sporangial sporulation, zoospore release, and motility was observed with 2 μg ml−1 in trifloxystrobin, and 5 μg ml−1 for azoxystrobin and kresoxim-methyl. Seed treatment with different concentrations of strobilurins enhanced seed germination and seedling vigor of sunflower to varying degrees compared to control. Highest seed germination was recorded at 10 μg ml−1 in kresoxim-methyl, and maximum seedling vigor was noticed with trifloxystrobin at 30 μg ml−1. The effect of strobilurins was tested as seed treatment, foliar application, and seed treatment followed by foliar application. Under greenhouse conditions none of the concentrations used, either as seed treatment and foliar application, were phytotoxic. For the three strobilurins, the seed treatment along with foliar application enhanced the protection of the plants as compared to only the treatment of seeds. Foliar spray treatments alone provided an intermediate control of the disease. Trifloxystrobin showed a better effect than kresoxim-methyl and azoxystrobin. Disease curative activity of trifloxystrobin was higher compared to kresoxim-methyl and azoxystrobin. Tested fungicides when applied on adaxial leaf surface showed partial translaminar activity, and disease inhibition was marginal. Loss of trifloxystrobin and azoxystrobin activity over time was low, indicating stable rainfastness residual activity. A trend in protection against downy mildew disease similar to greenhouse results was evident in the field trials. This is the first report of strobilurins exhibiting high activity against P. halstedii and is a promising fungicide for controlling sunflower downy mildew disease by seed treatment and foliar spray.  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