全文获取类型
收费全文 | 645篇 |
免费 | 23篇 |
专业分类
林业 | 34篇 |
农学 | 102篇 |
基础科学 | 15篇 |
167篇 | |
综合类 | 39篇 |
农作物 | 31篇 |
水产渔业 | 38篇 |
畜牧兽医 | 144篇 |
园艺 | 13篇 |
植物保护 | 85篇 |
出版年
2023年 | 9篇 |
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 9篇 |
2018年 | 14篇 |
2017年 | 17篇 |
2016年 | 21篇 |
2015年 | 15篇 |
2014年 | 12篇 |
2013年 | 48篇 |
2012年 | 28篇 |
2011年 | 42篇 |
2010年 | 19篇 |
2009年 | 24篇 |
2008年 | 26篇 |
2007年 | 37篇 |
2006年 | 21篇 |
2005年 | 21篇 |
2004年 | 8篇 |
2003年 | 20篇 |
2002年 | 21篇 |
2001年 | 19篇 |
2000年 | 19篇 |
1999年 | 14篇 |
1998年 | 6篇 |
1997年 | 11篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 11篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 15篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 10篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1969年 | 4篇 |
1968年 | 3篇 |
1967年 | 3篇 |
排序方式: 共有668条查询结果,搜索用时 15 毫秒
31.
The ethyl acetate, acetone and methanol extracts of Wrightia tinctoria bark showed antinociceptive activity on acetic acid-induced writhing test in mice, their effects being comparable to that of acetylsalicylic acid. 相似文献
32.
The aerial parts of Malvastrum coromandelinum showed antinociceptive activity in the 0.6% acetic acid-induced writhing test in mice, the effects of acetone extract (200 mg/kg, p.o.) being comparable with acetylsalicylic acid (100 mg/kg, p.o.) 相似文献
33.
Shade is one of the important limiting factors in intercropped agro-ecosystems. Objective of this work is to analyze the role
of eight foliar traits of juvenile plants of five different species of Jasminum grown under coconut shade. The results reveal the shade tolerant J. pubescence to produce more number of nodes and longer shoots in all the three seasons studied. J. grandiflorum produced longer leaves and internodal distance than other species tested. Winter season shoots were longer with more number
of nodes and longer internodal distances than rainy season. Results are discussed in relation to the adaptive behavior of
plants to shade. 相似文献
34.
Ilias S Frydas Ivan Trus Lise K Kvisgaard Caroline Bonckaert Vishwanatha RAP Reddy Yewei Li Lars E Larsen Hans J Nauwynck 《Veterinary research》2015,46(1)
In this study, the pathogenic behavior of PRRSV 13V091 and 13V117, isolated in 2013 from two different Belgian farms with enzootic respiratory problems shortly after weaning in the nursery, were compared with the Belgian strain 07V063 isolated in 2007. Full-length genome sequencing was performed to identify their origin. Twelve weeks-old pigs were inoculated intranasally (IN) with 13V091, 13V117 or 07V063 (9 pigs/group). At 10 days post inoculation (dpi), 4 animals from each group were euthanized and tissues were collected for pathology, virological and serological analysis. 13V091 infection resulted in the highest respiratory disease scores and longest period of fever. Gross lung lesions were more pronounced for 13V091 (13%), than for 13V117 (7%) and 07V063 (11%). The nasal shedding and viremia was also most extensive with 13V091. The 13V091 group showed the highest virus replication in conchae, tonsils and retropharyngeal lymph nodes. 13V117 infection resulted in the lowest virus replication in lymphoid tissues. 13V091 showed higher numbers of sialoadhesin− infected cells/mm2 in conchae, tonsils and spleen than 13V117 and 07V063. Neutralizing antibody response with 07V063 was stronger than with 13V091 and 13V117. It can be concluded that (i) 13V091 is a highly pathogenic type 1 subtype 1 PRRSV strain that replicates better than 07V063 and 13V117 and has a strong tropism for sialoadhesin− cells and (ii) despite the close genetic relationship between 13V117 and 07V063, 13V117 has an increased nasal replication and shedding, but a decreased replication in lymphoid tissues compared to 07V063.
Electronic supplementary material
The online version of this article (doi:10.1186/s13567-015-0166-3) contains supplementary material, which is available to authorized users. 相似文献35.
N. Vinod Kumar B. Sreedevi A. Karthik S. Vijaya Lakshmi A. Geetha Reddy D. Sreenivasulu 《Veterinary research communications》2014,38(4):323-328
An outbreak of sheep associated malignant catarrhal fever in crossbred cattle in a village of Andhra Pradesh, southern India, affected thirteen adult cows and two calves from a population of forty animals. All the affected animals were died between December and January 2013–14. The clinical and gross postmortem findings were typical of MCF in Indian crossbred cattle. Migrating sheep flocks were suspected source of infection for the cattle. The diagnosis was confirmed by heminested PCR in all the affected cattle and the suspected sheep flock. The PCR provided evidence of ovine herpes virus type 2. 相似文献
36.
37.
Development of Core Subset of Finger Millet Germplasm Using Geographical Origin and Data on 14 Quantitative Traits 总被引:6,自引:0,他引:6
Hari D. Upadhyaya C. L. L. Gowda R. P. S. Pundir V. Gopal Reddy Sube Singh 《Genetic Resources and Crop Evolution》2006,53(4):679-685
Finger millet [Eleusine coracana (L.) Gaertn.] is an important cereal food crop in Africa and South Asia. It is a hardy crop that can be grown in very diverse
environments from almost at sea level to about 2400 m.a.s.l. Finger millet has an excellent food value as its seeds contain
protein ranging from 7 to 14% and are particularly rich in methionine amino acid, iron, and calcium. Despite all these merits,
this crop has been neglected from the main stream of crop improvement research. One of the means to boost its production and
productivity is to enhance utilization of finger millet germplasm to breed superior varieties. Keeping this objective in view,
a core subset of finger millet germplasm (622 accessions) based on origin and data on 14 quantitative traits was developed
from the entire global collection of 5940 accessions held in the genebank at ICRISAT, Patancheru, India. The comparison of
means, variances, frequency distribution, Shannon-Weaver diversity index (H′) and phenotypic correlations indicated that the
core subset represents the entire collection. These tests indicated that sampling was optimal and the diversity has been captured
very well in the core subset. The correlation analysis indicated that panicle exsertion and longest finger length could be
given lower priority in the future germplasm evaluation work of finger millet. 相似文献
38.
Faisal Rashid Sofi S. M. Zofair Vijay Kumar Reddy Surasani K. K. Sabha Nissar Rajkumar Ratankumar Singh 《Journal Of Aquatic Food Product Technology》2013,22(3):253-263
Fatty fish have been recognized as potential raw material for production of minced meat; however, they are prone to oxidation and further deterioration. In the present study, the effect of washing and antioxidant (tannic acid) treatment on the quality of minced meat of Trachurus trachurus (horse mackerel) during frozen storage was observed. Minced meat of Trachurus trachurus was divided into three lots (T0, T1, and T2). T1 was washed with cold water, T2 with cold water containing tannic acid (100 mg/kg), and T0 was not washed. All the lots were frozen at ?40°C and stored at ?20 ± 2°C for 125 days and were subjected to biochemical, microbiological, and sensory evaluation at regular intervals of 25 days. The antioxidant treatment with tannic acid at the dosage used was found effective in minimizing the rancidity problems of minced meat (T2), compared to T0 and T1. During the whole period of storage, samples from T2 showed good quality in terms of microbiological, biochemical, and sensory analysis compared to T1 and T0. 相似文献
39.
Namratha Reddy David M. Crohn Frederick F. Ernst Vijayasatya N. Chaganti 《Compost science & utilization》2013,21(3-4):164-176
ABSTRACT Most composters in the United States use open-windrows. During high intensity precipitation events, uncontained water running off of the surface of the compost piles can potentially contaminate surface waters with nutrients and metals. Water that is absorbed poses no runoff concern but may threaten groundwater quality. To gain insight into these processes, stormwater runoff fractions and water holding capacity of compost piles have been characterized for greenwaste (GW) and biosolids (BS) materials. Laboratory scale experiments were conducted using days 1, 7, and 14 materials representing three different stages of composting. This study also evaluated sloped and flat-top as different pile geometries and surfactant use for promoting infiltration. Results indicate that fresh materials were most hydrophobic and the infiltration rates increased with increased composting times. The water storage capacity of the compost pile increased with the age of the compost pile. Compost water storage capacities could not be reliably estimated as the difference between field capacity and as-received water contents. 相似文献
40.
Availability, fixation, and transformation of added P were studied in a 16-week incubation experiment with a Vertisol amended with farmyard manure in pots with 500 g soil each. P availability, as measured by Olsen P, decreased for up to 8 weeks with various rates of added P, when no manure was applied. In the presence of farmyard manure, P availability decreased during the first 6 weeks and then showed a considerable increase from the 8th week onwards. P fixation increased for up to 8 weeks with the rates of P in the absence of manure. With manure application, P fixation increased only during the first 6 weeks and thereafter decreased continuously. Thus the presence of farmyard manure shortened the period of P fixation and promoted its availability. After 16 weeks of incubation, when manure and fertilizer P were applied together, P was transformed into labile organic (NaHCO3–P), moderately labile organic P (NaOH-P), and calcium-bound inorganic P (HCl-P). When manure was not applied. P accumulated predominantly as labile inorganic (NaHCO3–P), moderately labile inorganic (NaOH-P), and inorganic HCl-P. The application of farmyard manure enriched long-term P fertility through NaHCO3–P and NaOH–P and a shortterm P supply as HCl-P. All fractions except inorganic NaOH-P showed good relationships with Olsen P. 相似文献