全文获取类型
收费全文 | 672篇 |
免费 | 33篇 |
国内免费 | 3篇 |
专业分类
林业 | 61篇 |
农学 | 35篇 |
基础科学 | 4篇 |
121篇 | |
综合类 | 109篇 |
农作物 | 29篇 |
水产渔业 | 47篇 |
畜牧兽医 | 237篇 |
园艺 | 8篇 |
植物保护 | 57篇 |
出版年
2023年 | 7篇 |
2022年 | 5篇 |
2021年 | 15篇 |
2020年 | 8篇 |
2019年 | 16篇 |
2018年 | 17篇 |
2017年 | 26篇 |
2016年 | 24篇 |
2015年 | 12篇 |
2014年 | 12篇 |
2013年 | 25篇 |
2012年 | 46篇 |
2011年 | 43篇 |
2010年 | 27篇 |
2009年 | 28篇 |
2008年 | 50篇 |
2007年 | 42篇 |
2006年 | 22篇 |
2005年 | 26篇 |
2004年 | 26篇 |
2003年 | 31篇 |
2002年 | 24篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 10篇 |
1988年 | 4篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1969年 | 6篇 |
1967年 | 4篇 |
1964年 | 3篇 |
1939年 | 2篇 |
排序方式: 共有708条查询结果,搜索用时 46 毫秒
101.
102.
Intr0ducti0nNorwayspruce(PiceaabiesKarst)is0l1eoflI1e111ostimportal1tc011iferinFra11ce.lnl99l,tI1etotaIareaofNorwaysprLICewasestimatedt0be723000I11112.ItsvoIUmewasl27Inilli0I1m3.Tl1eanl1uaIvoILl111eiI1crc-mentwas5.74millionm3.ltiswideIyacceptedII1atIargeri11itialspacingssI1ouldbeusednow.l111940's,thedensity0ftl1epIantatiol1rangedfr0m5000to10000stems/hm2.Nowtl1einitiaIdensityvariesbetweenI000to250Ostems/I1m2.TI1eIargestspacit1g111aybe650~800stems/hm2.S0ithasasignifica11cetostLldyt… 相似文献
103.
Ecology of Salmonids in Estuaries around the World: Adaptations,Habitats and Conservation Colin D. Levings University of British Columbia Press 2016. Vancouver, 388 pp,ISBN‐13: 978‐0774831734, CDN 75; USD 83; GBP 71 (hardcover).
下载免费PDF全文
![点击此处可从《Fish and Fisheries》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lia Chalifour Morgan J. Black Kieran Cox Sarah Schroeder Francis Juanes 《Fish and Fisheries》2017,18(4):790-791
104.
Complete removal of roots from soil samples is a prerequisite for most of the chemical and biological analyses. A simple electrostatic method of separating roots from sieved, largely mineral soil substrates was optimized and examined by the addition of 14C labeled fine roots to sandy, silt loamy and clay loamy samples. Depending on soil texture, between 40% and 50% of fine roots can be removed from 100 g of sieved soil in less than 10 minutes. The root‐free soil substrate and the extracted roots can be used for analyzes or experiments immediately after the separation. The proportion of the mineral particles remaining in the root fraction depends on duration of separation, distance between the charged plate and the sample, and soil texture. The proportion of separated mineral particles is about 90%—95% (w/w) in sandy and 70%—85% in silt loamy and clay loamy substrates. The electrostatic method of root separation may take place before the analysis of Ct and Nt contents, and is suitable for soil samples preparation for incubation experiments. 相似文献
105.
106.
Genevieve Patrick Andrea M. Tarnecki Nicole Rhody Ryan Schloesser Kevan Main Roy Yanong Ruth Francis‐Floyd 《Aquaculture Research》2019,50(12):3793-3801
Almaco jack (Seriola rivoliana Valenciennes) is an excellent candidate for aquaculture due to its fast growth rate and high market value. While S. rivoliana have adapted well to captivity, survival at early life stages can be improved to increase profitability during production. A wide range of variables cause larval mortalities but high bacterial loads in rearing tanks are often correlated with these losses. The aim of this study was to investigate the effect of egg disinfection on bacterial load and hatch rate of S. rivoliana. Disinfectants tested included formalin (F100 and F200; 100 and 200 mg/L, respectively, for 60 min), hydrogen peroxide (HPO; 300 mg/L for 10 min) and peracetic acid/hydrogen peroxide (PAA/HPO; 15.7 mg/L/39.6 mg/L for 1 min). Concentrations and contact times were determined based on current use in marine aquaculture and preliminary trials. Eggs treated with HPO and F100 had significantly higher hatch rates than the untreated control group. All treatments significantly decreased total Vibrio counts compared to untreated eggs; however, total bacterial counts were only decreased following treatments with PAA/HPO and F200. To prevent egg mortality due to bacterial overgrowth, consideration should be given to the use of surface disinfection using HPO or F100. Future studies should investigate the use of peracetic‐based products at lower doses. 相似文献
107.
108.
109.
110.
This article outlines the principal gastrointestinal protozoal diseases that have been recorded as affecting reptiles. It covers 9 genera of flagellates/amoebae, 1 ciliate genus, and 5 genera of coccidia, describing their pertinent anatomy and what is known about their epidemiology, including clinical presenting signs and intestinal pathological changes. The agents are initially discussed individually and, to avoid repetition, common information about diagnostics, treatment, and control is then presented. 相似文献