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   43篇
  免费   6篇
林业   10篇
农学   2篇
  8篇
综合类   2篇
农作物   7篇
水产渔业   1篇
畜牧兽医   16篇
植物保护   3篇
  2024年   1篇
  2021年   1篇
  2020年   2篇
  2019年   2篇
  2018年   3篇
  2017年   4篇
  2016年   5篇
  2015年   2篇
  2014年   3篇
  2013年   2篇
  2012年   9篇
  2011年   6篇
  2010年   4篇
  2009年   1篇
  2007年   2篇
  2006年   1篇
  2004年   1篇
排序方式: 共有49条查询结果,搜索用时 15 毫秒
1.
2.
Soil ecosystem is experiencing stresses due to climate change, and soil inhabitants try to demonstrate their inherent resistance and resilience against those stresses. Application of nanomaterials as agricultural inputs could bring shifts in resistance and resilience patterns of soil microbes and associated enzymes, especially under short-term heat stress. With this background, the impacts of multi-walled carbon nanotube (MWCNT) on the resistance and resilience of soil biological indicators were evaluated. An incubation experiment was conducted with varied MWCNT concentrations (0, 50, 100, 250, and 500 mg kg-1 soil) for 90 d after 24-h heat stress at 48 ±2 ℃ to assess the impacts of MWCNT on soil enzyme activities and microbial populations vis-à-vis their resistance and resilience indices under short-term exposure to heat stress. Enzyme activities were reduced after exposure to heat stress. Resistance indices of enzyme activities were enhanced by MWCNT application on day 1 after heat stress, whereas there was no recovery of enzyme activities after 90-d incubation. Like soil enzyme activities, resistance index values of soil microbial populations followed the similar trend and were improved by MWCNT application. Multi-walled carbon nanotube has the potential to improve resistance indices of soil enzyme activities and microbial populations under heat stress, although they could not recover to their original state during periodical incubation after heat stress. This study helps to understand the relative changes of biological indicators under MWCNT and their ability to withstand heat stress.  相似文献   
3.
Spot blotch (SB), caused by Bipolaris sorokiniana, is a devastating disease of wheat globally, especially in South Asia and South America. Understanding the genetics of resistance to SB is important for developing breeding strategies to improve resistance. A panel of 301 genotypes from Afghanistan was phenotyped over two crop seasons using a mixture of virulent B. sorokiniana isolates and genotyped using DArTSeq to obtain genome-wide markers. Fifty genotypes (16.6%) showed disease scores less than the resistant control. Principal component analysis using the genotypic data clustered the genotypes into five different groups. Among models used for genome-wide association mapping, the multilocus mixed model, and fixed and random model circulating probability unification algorithms were most effective in identifying significant marker-trait associations (MTA). Twenty-five MTAs at p ≤ .001 were identified on chromosomes 1A, 1B, 1D, 2B, 2D, 3A, 3B, 4A, 5A, 5B, 6A, 7A, and 7D, indicating the quantitative nature of resistance to SB. Phenotypic variation explained by these markers ranged from 2.0% to 17.7%, and genomic regions on the chromosomes 1D, 2D, 3A, 3B, 4A, 5A, and 5B coincided with loci identified in previous studies. Three single nucleotide polymorphism (SNP) markers on chromosomes 1B (SNP 1113207) and 5A (SNPs 5411867 and 998276) were significant in both crop seasons as well as in the combined analysis across seasons. Marker 5411867 is close to Vrn-A1, shown to be associated with SB in previous studies. Furthermore, among known SB resistance genes, Sb2 on chromosome 5B was predicted to be significant in this panel.  相似文献   
4.
5.
India is the world’s tenth most forested nation with 76.87 M ha of forest and tree cover occupying 23.4% of its geographical area. Forests—with their intrinsic of carbon sequestration and storage values—are in the front line of India’s climate change mitigation strategies. This paper provides estimates of sequestered carbon in India’s forest and tree cover for the years 1995 and 2005 as per the IPCC good practice guidelines method. It is based on the primary data for the soil carbon pool through collecting soil samples by laying out quadrats across the country and secondary data for the growing stock of all forest and tree cover in the country. The estimates are compared with current and future projected emissions. It is found that conservation policies have resulted in increase of the country’s forest carbon stocks from 6244.8 to 6621.6 Mt with an annual increment of 37.7 Mt of the carbon from 1995 to 2005. Annual CO2 removal by the forests is enough to neutralise 9.3% of the country’s 2000 level emissions. Continued removals by the forest and tree cover would offset 6.5 and 4.9% of India’s projected annual emissions in 2010 and 2020 respectively. Economically, the annual value of this forest carbon in the international market is about US $188 million. The result is of use in the REDD and REDD+ context for India.  相似文献   
6.
Objective The aims of this study were (1) to determine the efficacy of adeno‐associated vector serotype 5 (AAV5) for delivering gene therapy to canine corneal fibroblasts (CCFs) and myofibroblasts (CCMs) using enhanced green fluorescent protein (GFP) marker gene and (2) to evaluate the cytotoxicity of AAV5 to CCFs and CCMs using an in vitro model. Methods Healthy donor canine corneas were used to generate primary CCFs by growing cultures in minimal essential medium supplemented with 10% fetal bovine serum. Canine corneal myofibroblasts were produced by growing cultures in serum‐free medium containing transforming growth factor β1 (1 ng/mL). An AAV5 titer (6.5 × 1012 μg/mL) expressing GFP under control of hybrid cytomegalovirus + chicken β‐actin promoters (AAV5‐gfp) was used to transduce CCF and CCM cultures. Delivered gene expression in CCFs and CCMs was quantified using immunocytochemistry, fluorescent microscopy, and real‐time PCR. Transduction efficacy of the AAV5 vector was determined by counting DAPI‐stained nuclei and EGFP‐positive cells in culture. Phase‐contrast microscopy, trypan blue, and dUTP nick end labeling (TUNEL) assays were used to determine the toxicity and safety of AAV5 in this canine corneal model. Results Topical AAV5 application successfully transduced a significant population of CCFs (42.8%; P < 0.01) and CCMs (28%; P < 0.01). Tested AAV5 did not affect CCF or CCM phenotype or cellular viability and did not cause significant cell death. Conclusions The tested AAV5 is an effective and safe vector for canine corneal gene therapy in this in vitro model. In vivo studies are warranted.  相似文献   
7.
We investigated the effects of Arbuscular Mycorrhiza (AM) fungi and various phosphorus (P) levels on the distribution and availability of P in dominant soils of Bihar, India. Potassium chloride (KCl)-P (labile P), sodium hydroxide (NaOH)-P (Fe-Al-bound P), hydrochloric acid (HCl)-P (Ca-bound P), and residual P (Res-P) fractions were analyzed in the soils under maize plant. Ca-bound P was the most abundant P fraction in the alkaline soils (65% of the total P) followed by neutral soil (35% of the total P), whereas it was less abundant (<4%) in the acidic soil type. Fe-Al-bound P was found to be highest for acidic soil (65% of the total P). Soils under the inoculation with Glomus mossae and control gave the highest and lowest values (15.63 mg kg?1 and 10.74 mg kg?1 respectively) for the labile fraction which was similar to the organically bound residual fractions of P (200.17 mg kg?1 and 193.66 mg kg?1 respectively. Inoculation of the soils with AM fungi leads to the redistribution of P fractions in different soils which consequently helps in improvement of available P in soil conducive for plant uptake.  相似文献   
8.
This research investigated the effect of repeated laundering and dry-cleaning on the physical and thermophysiological comfort properties such as air permeability, water vapour resistance and thermal resistance of fabrics made of meta-aramid (Nomex®) fibre. Two different types of fabric were selected for the study and subjected to repeated laundering and dry-cleaning (1, 5 and 10 cycles), which is commercially used for the care and maintenance of these fabrics. The fabric thickness, areal density, thermal resistance and water vapour resistance values increased with the number of laundering cycles, whereas the air permeability decreased due to the fabric shrinkage and swelling. On the other hand, the thickness and air permeability of the dry-cleaned fabric samples increased with the number of cycles; while the water vapour resistance and thermal resistance decreased. The scanning electron microscopy images showed the structural changes as indicated by the longitudinal fibrillation in the fabrics subjected to laundering or dry-cleaning.  相似文献   
9.
10.
Dahiya R  Gautam H 《Marine drugs》2010,8(8):2384-2394
The present study deals with the first total synthesis of the proline-rich cyclopolypeptide stylisin 2 via a solution phase technique by coupling of the Boc-L-Pro-L-Ile-L-Pro-OH tripeptide unit with the L-Phe-L-Pro-L-Pro-L-Tyr-OMe tetrapeptide unit, followed by cyclization of the resulting linear heptapeptide fragment. The chemical structure of the finally synthesized peptide was elucidated by FTIR, 1H/13C-NMR and FAB MS spectral data, as well as elemental analyses. The newly synthesized peptide was subjected to antimicrobial screening against eight pathogenic microbes and found to exhibit potent antimicrobial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans, in addition to moderate antidermatophyte activity against pathogenic Trichophyton mentagrophytes and Microsporum audouinii when compared to standard drugs--gatifloxacin and griseofulvin.  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