全文获取类型
收费全文 | 223篇 |
免费 | 12篇 |
国内免费 | 1篇 |
专业分类
林业 | 18篇 |
农学 | 12篇 |
基础科学 | 1篇 |
68篇 | |
综合类 | 12篇 |
农作物 | 27篇 |
水产渔业 | 16篇 |
畜牧兽医 | 52篇 |
园艺 | 7篇 |
植物保护 | 23篇 |
出版年
2023年 | 5篇 |
2022年 | 14篇 |
2021年 | 15篇 |
2020年 | 20篇 |
2019年 | 20篇 |
2018年 | 20篇 |
2017年 | 16篇 |
2016年 | 16篇 |
2015年 | 11篇 |
2014年 | 7篇 |
2013年 | 20篇 |
2012年 | 17篇 |
2011年 | 14篇 |
2010年 | 4篇 |
2009年 | 9篇 |
2008年 | 12篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2003年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有236条查询结果,搜索用时 46 毫秒
101.
Gholam Ali Kojouri Camellia Taghadosi Hassan Momtaz Ehsan Taheri 《Journal of Equine Veterinary Science》2009
Leptospirosis is a widespread zoonotic disease that affects humans and many species of animals. Leptospiral organisms have long been presumed to be associated with the presence of equine recurrent uveitis (ERU). The connection between ERU and leptospirosis can be established using various techniques. In the current study, we used a polymerase chain reaction (PCR) assay to help establish a diagnosis of ERU caused by Leptospira infection and compared the results with those of enzyme-linked immune assay (ELISA). A total of 31 and 30 serum samples were taken from horses with ERU (based on clinical diagnosis) and horses that were healthy, respectively, between June 2007 and December 2008. The results showed that from 31 affected horses, a total of seven and five samples were positive for leptospiral infection using PCR and ELISA, respectively, whereas there was no evidence of infection with Leptospira spp. in 30 serum samples of healthy horses. All of the positive samples in ELISA were also positive by PCR, whereas PCR detected two positive cases that were negative by ELISA. Although there was no significant difference between these two methods, it is apparent that PCR may be a more reliable tool for detecting the presence of leptospires in ERU. 相似文献
102.
Zhou Y Fuentes-Hernandez C Shim J Meyer J Giordano AJ Li H Winget P Papadopoulos T Cheun H Kim J Fenoll M Dindar A Haske W Najafabadi E Khan TM Sojoudi H Barlow S Graham S Brédas JL Marder SR Kahn A Kippelen B 《Science (New York, N.Y.)》2012,336(6079):327-332
Organic and printed electronics technologies require conductors with a work function that is sufficiently low to facilitate the transport of electrons in and out of various optoelectronic devices. We show that surface modifiers based on polymers containing simple aliphatic amine groups substantially reduce the work function of conductors including metals, transparent conductive metal oxides, conducting polymers, and graphene. The reduction arises from physisorption of the neutral polymer, which turns the modified conductors into efficient electron-selective electrodes in organic optoelectronic devices. These polymer surface modifiers are processed in air from solution, providing an appealing alternative to chemically reactive low-work function metals. Their use can pave the way to simplified manufacturing of low-cost and large-area organic electronic technologies. 相似文献
103.
104.
Khan I Nisar M Shah MR Shah H Gilani SN Gul F Abdullah SM Ismail M Khan N Kaleem WA Qayum M Khan H Obaidullah Samiullah Ullah M 《Fitoterapia》2011,82(7):1003-1007
Current study was conducted to identify constituents of Taxus wallichiana Zucc. that might be responsible for its folk use in anti-inflammatory conditions. Taxusabietane A was isolated from the bark extract of Taxus wallichiana Zucc. Taxusabietane A was analyzed for in-vitro and in-vivo anti-inflammatory activities using Lipoxygenase (LOX) inhibition assay and carrageenan-induced paw edema model. Taxusabietane A revealed considerable LOX inhibitory activity with the IC50 value being 57 ± 0.31. Standard compound Baicalein showed the IC50 value being 22.1 ± 0.03 μM. Taxusabietane A also showed significant (5 and 10 mg/kg) anti-inflammatory activity induced by carrageenan. However, this study highlighted the potential of Taxusabietane A to be further explored as a new lead compound for management of conditions associated with inflammation. 相似文献
105.
Javad Sadeghinezhad Zahra Ganji Sirous Sadeghian Chaleshtori Hadis Bojarzadeh Mahdi Aghabalazadeh Asl Ali Bayat Khomejini Ehsan Roominai Mohsen Hosseini Margherita De Silva 《Anatomia, histologia, embryologia》2021,50(6):1026-1033
Sheep have been used as translational models of human postnatal testicular development. However, the morphometric features of the normal developing testis in sheep embryos have not been previously investigated using stereology. The objective of the present work was to establish normal quantitative parameters for fetal testicular tissue components in sheep, using unbiased design-based stereological methods. Twenty-four sheep embryos were divided into four gestational age groups (9–11, 12–14, 15–17 and 18–20 weeks of gestation) on the basis of the embryos’ crown-rump length. Isotropic, systematic uniform random sections of the left testes were obtained by employing the orientator method. Testicular total volume, the absolute and proportional volumes occupied by the seminiferous tubules and interstitial tissue, as well as the seminiferous tubule length, were estimated using the point-counting system and the unbiased counting frame principle. All the parameters, with the exception of the interstitial tissue's fractional volume, gradually increased along with gestational age, with the maximum increase especially seen in the late fetal stages. The proportional volume of the interstitial tissue, on the other hand, showed a decreasing trend along with increasing gestational age. The absolute volume of the testes, of the seminiferous tubules and of the interstitial tissue, and the length of the seminiferous tubules showed a significant (p< 0.05) positive linear correlation with gestational age. Several similarities were observed with human testicular embryogenesis. The stereological data emerging from the present study might prove useful as basic contribution to the fields of andrology and embryology and stimulate further research in these areas. 相似文献
106.
Wang Xuemei Xu Kai Miao Wenhao Gao Linhao Ullah Saif Lyu Yueming Wang Xiangping 《European Journal of Forest Research》2022,141(5):927-938
European Journal of Forest Research - Increasing drought associated with climate warming (i.e., hotter drought) is seriously threatening tree growth and survival across the world. Previous studies... 相似文献
107.
Hafeez Abdul Ullah Zia Khan Rifat Ullah Ullah Qudrat Naz Shabana 《Tropical animal health and production》2020,52(5):2499-2504
Tropical Animal Health and Production - The current research study was designed to determine the inclusion of 2% dietary essential coconut oil with and without coccidiosis challenge on... 相似文献
108.
109.
Fasih Ullah HAIDER Jeffrey A. COULTER Liqun CAI Saddam HUSSAIN Sardar Alam CHEEMA Jun WU Renzhi ZHANG 《土壤圈》2022,32(1):107-130
The degradation of soil fertility and quality due to rapid industrialization and human activities has stimulated interest in the rehabilitation of low-fertility soils to sustainably improve crop yield. In this regard, biochar has emerged as an effective multi-beneficial additive that can be used as a medium for the amelioration of soil properties and plant growth. The current review highlights the methods and conditions for biochar production and the effects of pyrolysis temperature, feedstock type, and retention time on the physicochemical properties of biochar. We also discuss the impact of biochar as a soil amendment with respect to enhancing soil physical (e.g., surface area, porosity, ion exchange, and water-holding capacity) and chemical (e.g., pH, nutrient exchange,functional groups, and carbon sequestration) properties, improving the soil microbiome for increased plant nutrient uptake and growth, reducing greenhouse gas emissions, minimizing infectious diseases in plants, and facilitating the remediation of heavy metal-contaminated soils. The possible mechanisms for biochar-induced amelioration of soil and plant characteristics are also described, and we consider the challenges associated with biochar utilization. The findings discussed in this review support the feasibility of expending the application of biochar to improve degraded soils in industrial and saline-alkali regions, thereby increasing the usable amount of cultivated soil. Future research should include long-term field experiments and studies on biochar production and environmental risk management to optimize biochar performance for specific soil remediation purposes. 相似文献
110.
Zahur AB Ullah A Hussain M Irshad H Hameed A Jahangir M Farooq MS 《Preventive veterinary medicine》2011,102(1):87-92
A sero survey was conducted during 2005-2006 to estimate the sero prevalence of PPR in the small ruminant population of Pakistan. A total of 2798 samples were collected including goats (1979) and sheep (819) from villages in 27 randomly selected districts. These were tested by cELISA for PPRV and true prevalence estimates were calculated by Rogan and Gladen estimator. Overall, 1273 (45.5%) were found positive; 980 (49.5%) of 1979 samples from goats and 293 (35.8%) of 819 serum samples from sheep were positive. The true sero-prevalence of PPR was estimated to be 48.5% (95% CI, 46.6-50.3), and 52.9% (95% CI, 50.7-55.1) and 37.7 (95% CI, 34.4-41.0) for goats and sheep, respectively. PPR virus is widely distributed all across Pakistan and has become an endemic infection of small ruminants. Since it is one of the leading causes of morbidity and mortality in small ruminants, it poses a serious threat to food security and the rural economy in Pakistan. 相似文献