全文获取类型
收费全文 | 176篇 |
免费 | 13篇 |
专业分类
林业 | 19篇 |
农学 | 2篇 |
基础科学 | 2篇 |
29篇 | |
综合类 | 10篇 |
农作物 | 24篇 |
水产渔业 | 28篇 |
畜牧兽医 | 47篇 |
园艺 | 3篇 |
植物保护 | 25篇 |
出版年
2024年 | 3篇 |
2022年 | 6篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 11篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 7篇 |
2015年 | 10篇 |
2014年 | 8篇 |
2013年 | 13篇 |
2012年 | 14篇 |
2011年 | 11篇 |
2010年 | 3篇 |
2009年 | 8篇 |
2008年 | 7篇 |
2007年 | 5篇 |
2006年 | 1篇 |
2005年 | 8篇 |
2004年 | 1篇 |
2003年 | 7篇 |
2002年 | 1篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1973年 | 3篇 |
1971年 | 3篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1965年 | 3篇 |
排序方式: 共有189条查询结果,搜索用时 15 毫秒
1.
The common pistachio psylla, Agonoscena pistaciae, is a serious global pest menacing pistachio orchards. Considering the dangers of using excessive chemical pesticides, it seems that using natural insecticides such as diatomaceous earth is a suitable way to lower the residual amount of highly hazardous pesticides. In this study, the effects of diatomaceous earth with different additives, including dipotassium hydrogen phosphate, polyurethane glue as a wood adhesive, and potassium silicate, were investigated in several concentrations over two years in orchard conditions. Although all treatments showed significant effects, the most effective treatments were (diatomaceous earth+dipotassium hydrogen phosphate) and (diatomaceous earth+polyurethane glue). Therefore, the use of diatomaceous earth combined with the additive materials mentioned can potentially be a safe method for the integrated management of the common pistachio psylla. 相似文献
2.
Mona Saleh Ehab Essawy Mohamed Shaalan Shaaban Osman Fatma Ahmed Mansour El-Matbouli 《Marine drugs》2022,20(7)
Marine bio-sourced chitosan nanoparticles (CSNP) are antimicrobial and immunomodulatory agents beneficial for fish medicine. Herein, dietary CSNP was investigated for the amelioration of the systemic inflammatory responses of an induced fish model. One hundred and forty-four rainbow trout were assigned to one pathogen-free and non-supplemented group (negative control), and three challenged groups: non-supplemented (positive control), CSNP-preventive, and CSNP-therapeutic. After a feeding experiment extended for 21 days, the organosomatic indices (OSI) and molecular aspects were assessed. After a challenge experiment extended for further 28 days, CSNP-therapeutic intervention was assessed on fish survival and systemic inflammatory responses on pathology, histo-morphology, and molecular aspects. With CSNP administration, OSI nonsignificantly decreased and the relative expression of targeted inflammatory-mediator genes was significantly increased. The CSNP-therapeutic fish showed an RPS of 80% as compared to the positive control group, and CSNP-therapeutic administration retained the highest gene expression augmentation up to 28 days after the challenge. Notably, the splenic reticulin fibers framework of the CSNP-therapeutic group retained the highest integrity among the groups during the infection. After recovery, reticulin fibers density in the CSNP-therapeutic samples was significantly higher than in the negative control group, which indicates high innate immunity. Thus, CSNP showed promising biotherapeutic features enhancing fish resistance against infections. 相似文献
3.
Ten Egyptian and imported entomopathogenic nematodes were evaluated for their pathogenicity to R. ferrugineus in both the laboratory and the field. In the laboratory, most nematodes were pathogenic to the pest larvae, pupae and adults. Larvae and adults were more susceptible to nematode infection (mostly 100% mortality) than pupae enclosed in their cocoons. In the field however, the highest insect larval mortality was 66.67% and most of nematodes failed in controlling the pest. Such failure could be due to hot weather, the tunnelling behaviour of the pest larvae and the too much sap in the infested sites in the trunks of palm trees. 相似文献
4.
W. Mubarak M. N. Saleh R. Sayed A. Ohtsuka T. Taguchi T. Murakami 《Anatomia, histologia, embryologia》2005,34(S1):34-35
Perineuronal nets (PNs) of condensed extracellular matrix (ECM) have been shown to characterize the microenvironment of individual neurons and the chemoarchitecture of some brain regions. In the present study, PNs in the hippocampus were visualized with a cationic iron colloid method for sulphated proteoglycan content and a plant lectin from Vicia villosa agglutinin (VVA) for N-acetylgalactosamine containing glycoconjugates. The ECM molecules were organized in reticular coats (PNs) around non-pyramidal cells in the Ammons horn (Corneu Ammons, CA) and subicular region, in addition to pyramidal neurons located in CA2 and CA3 regions. CA2 stratum pyramidale exhibited the most intense staining of its PNs and a diffuse intervening neutrophil labelling, while CA3 region showed a graded fashion of staining intensity. The subiculum displayed intensely stained perineuronal coats. Notably, the hippocampal perineuronal nets revealed overlapped staining characteristics with both staining methods. However, cell coats of the subicular neurons showed various degrees of labelling characteristics with both markers. It is suggested that the PNs in the hippocampus are correlated with the fast spiking inhibitory GABAergic neurons and their target pyramidal cells, and this is important to keep the excitatory elements under control and therefore control the information processes within the hippocampus. 相似文献
5.
6.
The present work aimed to study the effects of high constant and alternating temperatures on the development and prey consumption by Dicyphus tamaninii Wagner (Het., Miridae) with Aphis gossypii Glover (Hom., Aphididae) as prey.Results showed that the predator was able to successfully develop and reach the adult stage, on average, after 20.1 () and 20.6 () days at a temperature of 30 ± 1 °C with A. gossypii as prey. On the other hand, it was not able to develop at 35 ± 1 °C, here all N1 instars used at the beginning of the experiments had died even before moulting to N2 instar. At alternating temperatures of 25/15 ± 1 °C, the predator reached the adult stage 23.7 () and 23.5 () days after egg hatching, whereas when the temperatures were increased to 35/22 ± 1 °C, it took a significantly shorter period: 20.6 () and 20.9 () days. In general, the highest mortality occurred during the first two nymphal instars. The total percentage mortality during development from N1 to adult stage was 30 % and 100 % at the constant temperatures 30 ± 1 °C and 35 ± 1 °C, respectively. At the alternating temperatures of 25/15 ± 1 °C, it was lowest with 16.5 %, while at 35/22 ± 1 °C, it was 20 %.The results of the experiments on prey consumption showed that an individual D. tamaninii consumed during its development to adult stage at 30 ± 1 °C an average of 442.2 (), 433.6 () aphids. At the constant temperature of 35 ± 1 °C, the average daily prey consumption started with 4 aphids and decreased continuously till it approached nil on the 9th day, where all predatory nymphs died. At the alternating temperatures of 25/15 ± 1 °C, the total prey consumption during development was, on average, 359.3 () and 297.0 () aphids, while at 35/22 ± 1 °C it was 348.5 () and 334.0 () aphids. The effect of the four temperatures on the prey consumption by D. tamaninii during the first 10 days after emergence was also studied. At a constant temperature of 30 ± 1 °C, a total of 446.4 () and 372.0 () aphids were consumed, compared to 40.6 () and 39.0 () at 35 ± 1 °C. At alternating temperatures of 25/15 ± 1 °C, the predatory adult consumed, on average, a total of 267.0 () and 207.0 () aphids. Increasing the temperature to 35/22 ± 1 °C resulted in a higher prey consumption by the adult predator, reaching 351.5 () and 267.7 () aphids over the same period.In conclusion, results indicated that D. tamaninii is a promising predator of the melon aphid at a temperature spectrum ranging from 15 ± 1 °C up to 35 ± 1 °C. 相似文献
7.
Two new flavones were isolated from the aerial parts of Retama raetam subsp. raetam. Their structures were established as luteolin 4'-O-neohesperidoside (1) and 5,4'-dihydroxy-(3",4"-dihydro-3", 4"-dihydroxy)-2",2"-dimethylpyrano-(5",6":7,8)-flavone (2) by means of spectroscopic methods. Also present was ephedroidin (4',5, 7-trihydroxy-8-(2-hydroxy-3-butenyl)-flavone). 相似文献
8.
Effect of feeding Aspergillus awamori and canola seed on the growth performance and muscle fatty acid profile in broiler chicken
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)
The aim of this study was to examine effects of dietary supplementation with Aspergillus awamori and feeding canola seed on the growth and fatty acid profile in broilers. Twenty‐eight chicks (15 days old) were assigned to the following groups: (1) control, fed a basal diet; (2) awamori, fed the basal diet supplemented with 0.05% A. awamori; (3) canola, fed a diet containing 5% canola seed; and (4) canola + awamori, fed the canola diet supplemented with A. awamori (seven birds/group). Body weight gain was increased by A. awamori but not influenced by canola seed. Breast muscle weight was increased in either awamori or canola groups. Although plasma triglyceride and cholesterol were decreased by feeding A. awamori or canola seed, fat content in the breast muscle were increased, accompanied by decrease in saturated fatty acids and increase in unsaturated fatty acids. Moreover, decreased thiobarbituric acid reactive substance and increased α‐tocopherol content in the breast muscle was observed in all experimental groups. In conclusion, these results suggested that feeding canola seed and A. awamori might improve growth performance, and modified muscle fatty acid profile and α‐tocopherol content, suggesting that they may improve meat quality. 相似文献
9.
Shaharudin Mohamad Azimi Zaki Noorhariza Mohd Saleh Mohd Nazre Mohd Noor Normah Midin Mohd Razik 《Genetic Resources and Crop Evolution》2022,69(7):2291-2299
Genetic Resources and Crop Evolution - Mangosteen (Garcinia mangostana var. mangostana) is an obligate apomictic species which does not require a fertilization process to produce seeds. The absence... 相似文献
10.
Saleh Taghvaeian José L. Chávez Walter C. Bausch Kendall C. DeJonge Thomas J. Trout 《Irrigation Science》2014,32(1):53-65
Research was conducted in northern Colorado in 2011 to estimate the crop water stress index (CWSI) and actual transpiration (T a) of maize under a range of irrigation regimes. The main goal was to obtain these parameters with minimum instrumentation and measurements. The results confirmed that empirical baselines required for CWSI calculation are transferable within regions with similar climatic conditions, eliminating the need to develop them for each irrigation scheme. This means that maize CWSI can be determined using only two instruments: an infrared thermometer and an air temperature/relative humidity sensor. Reference evapotranspiration data obtained from a modified atmometer were similar to those estimated at a standard weather station, suggesting that maize T a can be calculated based on CWSI and by adding one additional instrument: a modified atmometer. Estimated CWSI during four hourly periods centered on solar noon was largest during the 2 h after solar noon. Hence, this time window is recommended for once-a-day data acquisition if the goal is to capture maximum stress level. Maize T a based on CWSI during the first hourly period (10:00–11:00) was closest to T a estimates from a widely used crop coefficient model. Thus, this time window is recommended if the goal is to monitor maize water use. Average CWSI over the 2 h after solar noon and during the study period (early August to late September, 2011) was 0.19, 0.57, and 0.20 for plots under full, low-frequency deficit, and high-frequency deficit irrigation regimes, respectively. During the same period (50 days), total maize T a based on the 10:00–11:00 CWSI was 218, 141, and 208 mm for the same treatments, respectively. These values were within 3 % of the results of the crop coefficient approach. 相似文献