全文获取类型
收费全文 | 201篇 |
免费 | 14篇 |
专业分类
林业 | 12篇 |
农学 | 27篇 |
基础科学 | 2篇 |
62篇 | |
综合类 | 13篇 |
农作物 | 11篇 |
水产渔业 | 14篇 |
畜牧兽医 | 41篇 |
园艺 | 5篇 |
植物保护 | 28篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 5篇 |
2021年 | 6篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 8篇 |
2017年 | 15篇 |
2016年 | 6篇 |
2015年 | 10篇 |
2014年 | 7篇 |
2013年 | 22篇 |
2012年 | 17篇 |
2011年 | 14篇 |
2010年 | 9篇 |
2009年 | 7篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有215条查询结果,搜索用时 15 毫秒
1.
Identification of internal control genes in milk‐derived mammary epithelial cells during lactation cycle of Indian zebu cow
下载免费PDF全文
![点击此处可从《Animal Science Journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
2.
Shagufta YASMEEN Nintu MANDAL Anupam DAS Pritam GANGULY Sanjay KUMAR Rajiv RAKSHIT 《土壤圈》2024,34(3):664-675
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.
Kai Wang Zhiqiang Zhu Huagang Huang Tingqiang Li Zhenli He Xiaoe Yang Ashok Alva 《Journal of Soils and Sediments》2012,12(4):556-564
Purpose
Soil contamination by multiple organic and inorganic contaminants is common but its remediation by hyperaccumulator plants is rarely reported. The growth of a cadmium (Cd) hyperaccumulator Sedum alfredii and removal of contaminants from Cd and polycyclic aromatic hydrocarbons (PAHs) co-contaminated soil were reported in this study. 相似文献4.
中国东南部红壤地区不同植被对土壤侵蚀和土壤养分的影响 总被引:31,自引:0,他引:31
TIAN Guang-Ming WANG Fei-Er CHEN Ying-Xu HE Yun-Feng FU Qing-Lin S. KUMAR LIN Qi 《土壤圈》2003,13(2):121-128
The effect of different vegetation systems including bamboo plantation (BP), forest ecosystem (CF), citrus orchard (Ctr) and farmland (FL) on erosion and nutrients of red soil were investigated in hilly region of southeastern China to find effective control measures for soil erosion. The results showed that all the vegetation systems could significantly reduce soil erosion and nutrient losses compared to bare land (Br). The ability of different vegetation systems to conserve soil and water was in the order of Ctr > BP > CF > FL > Br. Vegetation could also improve soil fertility. The soil organic matter, total N and total P contents were much higher in all the vegetation systems than in bare land, especially for the top soils. Vegetation systems improved soil physical properties remarkably. Compared to the bare land, soil organic matter, TP, TK and available K, especially soil microbial biomass C, N and P, increased under all the vegetation covers. However, they were still much lower than expected, thus these biological measurements are still needed to be carried out continuously. 相似文献
5.
Lei Y Mulchandani P Chen W Mulchandani A 《Journal of agricultural and food chemistry》2005,53(3):524-527
A microbial biosensor for rapid, sensitive, selective, and cost-effective determination of the total content of organophosphorus nerve agents with p-nitrophenyl substituent is reported. The biosensor consisted of genetically engineered PNP-degrader Pseudomonas putida JS444 expressing organophosphorus hydrolase (OPH) on its cell surface immobilized on a dissolved oxygen electrode. Surface-expressed OPH catalyzed the hydrolysis of organophosphorus pesticides with p-nitrophenyl substituent such as paraoxon, methyl parathion, and parathion to release p-nitrophenol that was oxidized by the enzymatic machinery of Pseudomonas putida JS444 to carbon dioxide while consuming oxygen. The oxygen consumption was measured and correlated to the concentration of organophosphates. The sensor signal and response time were optimized with 0.086 mg dry weight of cell and operating in 50 mM pH 7.5 citrate-phosphate buffer with 50 microM CoCl(2) at room temperature. When operated at optimized conditions, the biosensor measured as low as 55 ppb of paraoxon, 53 ppb of methyl parathion, and 58 ppb of parathion without interference from most phenolic compounds and other commonly used pesticides, such as atrazine, coumaphos, sutan, sevin, and diazinon. The operational life of the microbial biosensor was approximately 5 days when stored in the operating buffer at 4 degrees C. 相似文献
6.
A serious outbreak of barley yellow dwarf luteovirus (BYDV, MAV-type) on wheat in the Garhwal Hills, Central Himalayas, India is reported. This is the first conclusive evidence based on serology for the presence of MAV-BYDV in India. 相似文献
7.
Parul Singh Anjil Kumar Srivastava Ashok Kumar Singh 《Pesticide biochemistry and physiology》2007,89(3):216-219
In this study, the comparison of cytogenetic effects of insecticide and fungicide in different phases of cell cycle was investigated in the root tip cells of barley (Hordeum vulgare L.). The seeds of H. vulgare L. Var. Karan 16 were treated with different concentrations (0.05%, 0.1% and 0.5%) of insecticide Profenophos (PF) and fungicide Mancozeb (MZ) for 6 h after presoaking durations of 7, 17 and 27 h.The different presoaking durations were used to bring the cells in various phases of cell cycle. Negative control was run parallel in distilled water. Cytogenetic examinations of root meristems exposed to the PF and MZ showed significant inhibition of mitotic index (MI) as well as significant increase in chromosomal aberrations (CAs). These parameters were dependent on the concentrations of insecticide and fungicide. The present study shows that PF and MZ both caused more damage in S phase of cell cycle which indicates that S phase is more sensitive in comparison to other phases. 相似文献
8.
9.
Four feeding experiments, replacing 25% (T1), 50% (T2), 75% (T3) and 100% (T4), by dry weight, of the live feed Artemia nauplii for Cyclop‐eeze, a new larval feed that was claimed to contain the highest known levels of astaxanthin and omega‐3 polyunsaturated fatty acids, were compared against a control that was fed with Artemia and egg custard alone, to the larvae of giant freshwater prawn Macrobrachium rosenbergii (De Man 1879). Analysis of different production characteristics of the larvae revealed that the highest survival up to postlarvae (PL) stage was obtained for T2 in which 50% of the Artemia nauplii were replaced by Cyclop‐eeze [freeze‐dried (FD) deep frozen (DF)], and the highest astaxanthin content of the larval tissue obtained in T4 in which the larvae were fed 100% Cyclop‐eeze, although the survival rate was the lowest in this treatment. The costs of different treatments were also compared. The Artemia consumption million−1 larvae was the highest in control (11490 g), followed by T1 (8240 g), T2 (4990 g), T3 (3730 g) and T4, which completely replaced Artemia from stage 5 onwards (1830 g). The highest consumption of Cyclop‐eeze million−1 larvae was in T4 (1670 and 10 880 g), followed by T3 (850 and 5560 g), T2 (410 and 2690 g) and T1 (230 and 1490 g) of FD and DF, respectively. The astaxanthin contents of the late‐stage larvae fed under the four treatments were 24.90, 27.40, 28.60 and 35.60 μg g−1 tissue for T1, T2, T3 and T4, respectively, while that of the control was 23.70 μg g−1. The lowest cost of live feeds million−1 PL was obtained for T2 (US$ 428.60), followed by T1 (US$ 490.46), control (US$ 529.07) and T3 (US$ 583.26), while it was the highest for T4 (US$ 890.93). The results indicated that Cyclop‐eeze could economically replace Artemia nauplii at 50% level that could significantly improve the survival and carotenoid composition of the larvae of M. rosenbergii. 相似文献
10.