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   237篇
  免费   10篇
林业   11篇
农学   22篇
  82篇
综合类   4篇
农作物   13篇
水产渔业   10篇
畜牧兽医   73篇
园艺   9篇
植物保护   23篇
  2023年   4篇
  2022年   8篇
  2021年   6篇
  2020年   10篇
  2019年   17篇
  2018年   8篇
  2017年   15篇
  2016年   6篇
  2015年   7篇
  2014年   10篇
  2013年   25篇
  2012年   11篇
  2011年   15篇
  2010年   11篇
  2009年   4篇
  2008年   11篇
  2007年   15篇
  2006年   13篇
  2005年   6篇
  2004年   4篇
  2003年   5篇
  2002年   5篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1998年   1篇
  1997年   2篇
  1995年   1篇
  1994年   1篇
  1992年   1篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1985年   2篇
  1980年   1篇
  1979年   1篇
  1978年   3篇
  1977年   2篇
  1975年   1篇
  1974年   1篇
  1970年   1篇
  1969年   1篇
排序方式: 共有247条查询结果,搜索用时 15 毫秒
151.
Variability studies were carried out among different accessions of Argyrolobium roseum for 12 metric traits under natural and cultivated conditions. Almost all characters showed higher values in cultivated than natural population. Leaf breadth recorded highest CV (30.59%). Highest percentage of vitexin and D-pinitol (0.208 and 0.773% dwb) was observed in RAR-7 and RAR-6, respectively, under cultivated conditions. Phenotypic coefficient was higher than genotypic coefficient of variation. The association analysis revealed that root yield had positive significant correlation with 100 seed weight (r=0.839) biomass yield (r=0.601), where biomass yield had a positive significant correlation with leaf length, single pod weight. High heritability (97.4–99.8%) coupled with moderate genetic advance ranged between (49–67%) as a percent of mean was observed for leaf breadth, pod length, total foliage biomass yield and total root yield/plant. This suggests that direct selection for these traits is suitable for the improvement of this crop.  相似文献   
152.
Tapeworm cysts were identified in liver of Wistar rats and it induced fibrosarcoma in liver and gastroenteropathy in stomach and intestine. The tapeworm larva was confirmed as Strobilocercus fasciolaris by PCR linked mitochondrial DNA sequencing. Light microscopy, special staining (masson trichrome) and immunoflouresence supported the diagnosis of fibrosarcoma. Infiltration of plasma cells, macrophages and eosinophils were observed in the liver section. Gastric mucosal hyperplasia, dilation of gastric glands with secretion, intestinal mucosal cell hyperplasia, proliferation of duodenal submucosal glands were confirmed by light microscopy and supported by PAS, AB staining. The concomitant development of hepatic sarcoma and gastroenteropathy by larvae of Taenia taeniaeformis (S. fasciolaris) infection is very rare and is the first reported case in Wistar rats to our knowledge.  相似文献   
153.
The effect of vitamins A, D3, E, and H supplementation on oxidative stress indices in Indian water buffaloes suffering from subclinical mastitis was investigated. Changes in the total oxidant capacity (TOC), total antioxidant capacity (TAC), nitric oxide (NO), and activities of glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) in milk were evaluated before and after the supplementation of vitamins A, D3, E, and H. The buffaloes suffering from subclinical mastitis revealed remarkable alterations in the milk oxidants/antioxidants balance shifted towards oxidative status. The buffaloes with subclinical mastitis revealed significantly (P?≤?0.01) higher TOC, NO contents, and CAT activity, while TAC content and GSH-Px activity were significantly (P?≤?0.01) lower in comparison with the healthy controls. However, SOD activity did not show any significant change. Supplementation of vitamins A, D3, E, and H to these animals revealed significant (P?≤?0.01) reduction in TOC, NO, and CAT, while a significant (P?≤?0.01) increase in TAC and GSH-Px activity was also evident. From the present study, it may be concluded that supplementation of these vitamins can help ameliorate the altered milk oxidants/antioxidants balance towards normalcy and, thus, ensue recovery from subclinical mastitis in the Indian water buffaloes.  相似文献   
154.
On an edible portion basis, pecan moisture, protein, lipid, total soluble sugars, and ash contents ranged from 2.1% to 6.4%, 6.0% to 11.3%, 65.9% to 78.0%, 3.3% to 5.3%, and 1.2% to 1.8%, respectively. With the exception of a high tannin (2.7%) Texas seedling, pecan tannin content was in a narrow range (0.6-1.85%). Unsaturated fatty acids (>90%) dominated pecan lipid composition with oleic (52.52-74.09%) and linoleic (17.69-37.52%) acids as the predominant unsaturated fatty acids. Location significantly influenced pecan biochemical composition. Pecan lipid content was negatively correlated with protein (r = -0.663) and total sugar (r = -0.625). Among the samples tested using SDS-PAGE a common pattern, with minor differences, in subunit polypeptide profiles was revealed. Rabbit polyclonal antibody-based immunoblotting experiments (Western blot) also illustrated the similarity in polypeptide profiles with respect to immunoreactivity. All tested cultivars registered similar immunoreactivity when their protein extracts (each at 1 mg/mL) were assessed using inhibition ELISAs (mean +/- standard deviation = 0.89 +/- 0.20; n = 27) with the USDA "Desirable" cultivar as the reference standard (immunoreactivity designated as 1.0).  相似文献   
155.
Recent studies on the protection afforded by moderate wine consumption against cardiovascular diseases have focused mainly on the activity of red wine in view of its high content of antioxidants, especially polyphenols. White wine lacks polyphenols, but it contains other compounds such as hydroxycinnamic acids (caffeic acid) and monophenols (tyrosol), which are known to have antioxidant properties. Therefore, this study was designed to examine the effect of white wine in myocardial ischemic-reperfusion injury. The experimental rats were gavaged with white wine (Soave Suavia "Le Rive" 2004) at a dosage of 6.5 mL/(kg.rat.day) for 30 days. Rats were divided into four groups: control sham (CS), wine-treated sham (WS), control ischemia (I)/reperfusion (R) (CIR), and wine + IR (WIR). All the rats in both IR groups underwent 30 min occlusion of the left anterior descending coronary artery followed by 8, 24 h, and 30 days of reperfusion (R). Significant reduction in infarct size (21 vs 39%, n = 6), cardiomyocyte (274 vs 384 counts/100 HPF, n = 6), and endothelial cell apoptosis (387 vs 587 counts/100 HPF) was observed in WIR as compared with CIR after 24 h of reperfusion. Echocardiography demonstrated significant increased fractional shortening (32 vs 22%) and ejection fraction (60 vs 44%) following 30 days of reperfusion in WIR rats compared to CIR ( n = 6). In addition, increased phosphorylation of AKT, Foxo3a, and eNOS were found in WS and WIR, as compared to their respective controls. The gel-shift analysis demonstrated significant upregulation of DNA binding activity of NF-kappaB in the white wine-treated groups. This report demonstrated for the first time that the white wine mediated cardioprotection in ischemic reperfused myocardium is through the PI-3kinase/Akt/FOXO3a/e-NOS/NF-kappaB survival pathway.  相似文献   
156.
As a result of methionine deficiency, legume proteins are considered to be incomplete, and therefore there is a need to explore ways to improve legume protein amino acid balance. Using rabbit anti-soybean sulfur-rich protein (SRP) polyclonal antibodies (pAb), sensitive immunoassays (nanogram sensitivity) were developed. The immunoassays detected SRP in all soybean seeds and soybean-based commercial samples examined. In addition, the presence of pAb cross-reactive proteins was detected in certain dry beans and oilseeds. The cross-reactive proteins were isolated using purified IgG-based immunoaffinity column chromatography. Biochemical analyses including N-terminal amino acid sequencing and amino acid composition indicated that the cross-reactive proteins were comparable to soybean SRP. The cross-reactive proteins contained methionine (1.6-2.4 residues/100 residues) and cysteine (2.4-3.6 residues/100 residues), which satisfies the FAO/WHO recommended pattern for sulfur amino acids in both adults and children (2-5 years old). The results suggest the presence of constitutive SRPs in several dry beans and oilseeds.  相似文献   
157.
The spot blotch disease of wheat is caused by Bipolaris sorokiniana, which is an anamorph (teleomorph Cochliobolus sativus). The disease mainly occurs in warm, humid wheat‐growing regions, and the Eastern Gangetic Plains (EGP) of South Asia is a hotspot. Significant progress has been made in recent years in characterizing the host–pathogen interaction. The study of the pathogen's life cycle and diversity have been an active area of research. A number of resistance sources have also been identified, characterized and used for breeding. Although immunity has not been observed in any genotype, cultivars displaying a relatively high level of resistance have been developed and made available to farmers. Further progress will require regular use of marker‐assisted breeding, genomic selection, gene editing and transgenic interventions. This review summarizes the current state of knowledge about genetic and breeding efforts on the wheat–B. sorokiniana pathosystem and discusses ways in which emerging tools can be used for future research to understand the mechanism involved in infection and for developing cultivars exhibiting a high level of resistance.  相似文献   
158.
Field experiments were conducted to evaluate the effects of zinc (Zn) fertilization on yield potentiality and quality of promising wheat varieties during winter seasons of 2013–14 and 2014–15 at the research farm of the Indian Agricultural Research Institute, New Delhi. Among genotypes, HD 2967 genotype proved as best in realizing the highest grain yield (4.89 Mg ha?1), net returns and benefit–cost ratio besides increased protein (13.4%) and wet gluten (29.4%) content in grain. Highest grain Zn concentration and recovery efficiency (RE) recorded in HD 2851 and HD 2687, respectively. HD 2932 registered lowest grain hardiness index (GHI) followed by PBW 343, indicating their better bread-making quality. With respect to Zn fertilization, application of 1.25 kg Zn Zn–ethylene diamine tetra acetic acid (Zn–EDTA) + 0.5% foliar spray at maximum tillering and booting stages resulted in the highest yields, grain Zn concentration and RE followed by 2.5 kg Zn (ZnSO4·7H2O) + 0.5% foliar spray at both stages. These treatments are also superior most with respect to grain quality parameters such as protein, wet gluten and starch content. From profitability viewpoint, 2.5 kg Zn (ZnSO4·7H2O) + 0.5% two foliar sprays were most remunerative with maximum net returns and benefit–cost ratio.  相似文献   
159.
The field experiments on calcareous sodic Vertisols were conducted on farmer’s fields in Purna valley of Vidarbha region of Maharashtra. The treatments comprised of different green manures (GMs); crop residues (CRs); gypsum. The chemical and biological properties after 2 years experiment showed that the application of gypsum recorded significant drop in pH and exchangeable sodium percentage (ESP) as compared to organic amendments. But later has outperformed with respect to biological activities viz., dehydrogenase activity (DHA) and microbial respiration and carbon sequestration by enhancing soil organic carbon (SOC), soil organic carbon (SOC) stock, soil microbial biomass carbon (SMBC) and labile carbon pool (POXC). Among the different organic amendments the application of dhaincha improved SMBC by 90%, microbial respiration by 104%, POXC by 59% and DHA by 265% as compare to control. High ESP of these soils showed negative relationship with microbial respiration and POXC (r = 0.48 and r = 0.43, p = < 0.05). While addition of biomass showed positive relationship with SMBC, microbial respiration, POXC and DHA (r = 0.93, r = 0.81, r = 0.83 and r = 0.91 p = < 0.01). The results of study showed green manuring in sodic black soil found to be alternative choice to gypsum, which besides gradual reclamation also enhance biological properties and carbon sequestration.  相似文献   
160.
The petiole on pigeonpea was removed for easy, precise inoculation of node with Phytophthora drechsleri f. sp. cajani. After node inoculation, 96.0% plants were infected compared with 89.0% after stem-cut inoculation. Among various nodes inoculated on 30-day-old plants, the 5th node had the greatest relative susceptibility (90.0%), followed by the 3rd node (78.0%). This technique was validated on different cultivars (ICP 7119, Bahar, MA 6 and MAL 13), and 586 lines were successfully screened in the field, confirming the rapidity and effectiveness of the technique for resistance screening.  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