全文获取类型
收费全文 | 4993篇 |
免费 | 150篇 |
国内免费 | 308篇 |
专业分类
林业 | 339篇 |
农学 | 420篇 |
基础科学 | 178篇 |
463篇 | |
综合类 | 1312篇 |
农作物 | 338篇 |
水产渔业 | 32篇 |
畜牧兽医 | 387篇 |
园艺 | 1799篇 |
植物保护 | 183篇 |
出版年
2024年 | 20篇 |
2023年 | 82篇 |
2022年 | 130篇 |
2021年 | 145篇 |
2020年 | 228篇 |
2019年 | 131篇 |
2018年 | 216篇 |
2017年 | 249篇 |
2016年 | 290篇 |
2015年 | 315篇 |
2014年 | 318篇 |
2013年 | 309篇 |
2012年 | 497篇 |
2011年 | 390篇 |
2010年 | 355篇 |
2009年 | 255篇 |
2008年 | 242篇 |
2007年 | 177篇 |
2006年 | 136篇 |
2005年 | 142篇 |
2004年 | 81篇 |
2003年 | 82篇 |
2002年 | 70篇 |
2001年 | 56篇 |
2000年 | 71篇 |
1999年 | 66篇 |
1998年 | 59篇 |
1997年 | 48篇 |
1996年 | 36篇 |
1995年 | 39篇 |
1994年 | 41篇 |
1993年 | 21篇 |
1992年 | 38篇 |
1991年 | 18篇 |
1990年 | 21篇 |
1989年 | 21篇 |
1988年 | 18篇 |
1987年 | 13篇 |
1986年 | 8篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1956年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有5451条查询结果,搜索用时 15 毫秒
31.
描述了毛竹的1个新栽培变种——绿槽龟甲竹。其竹秆下部一段的节交互歪斜,上下节在一侧相连,而节间在另一侧偏肿呈龟甲状,竹秆黄色,且龟甲状秆对称绿色纵条纹,分枝一侧纵沟槽绿色,叶片有淡黄色细纵条纹。 相似文献
32.
后备优质晚稻新品种引种试验 总被引:1,自引:0,他引:1
进行8个优质稻新品种的引种试验,试验结果表明:8个品种均表现米质优,有7个品种生育期适宜、适应性较广,可作为宁德市蕉城区优质稻后备品种继续试种。 相似文献
33.
《Communications in Soil Science and Plant Analysis》2012,43(2):220-230
Different relationships between soil-test methods results have been reported in several agricultural regions. Differences in the same soil-test procedure (e.g., soil/solution ratio) exist between soil-testing laboratories from different agricultural regions. Our objectives were to (1) determine the effect of soil/solution ratio on the amount of phosphorus removed by Bray 1 and Mehlich 3 methods, (2) compare the amounts of phosphorus removed by Bray 1 and Mehlich 3 in Mollisols from the Pampean region, and (3) determine whether soil/solution ratio affects the relationship between Bray 1 and Mehlich 3. Soil phosphorus availability was determined with two extractants (Bray 1 and Mehlich 3), using two soil/solution ratios (1:10 and 1:8, wt/v) in 72 soils (noncalcareous, loess-derived Molisolls) from the Pampean region. The amount of phosphorus removed was 20–24% greater when using 1:10 than 1:8 (wt/v) soil/solution ratio. This effect was significantly greater in Bray 1 than in Mehlich 3 (p = 0.04). When compared using the same soil/solution ratio, Mehlich 3 removed 4 to 8% more phosphorus than Bray 1. The soil/solution ratio used in the comparison affected the relationship between both extractants. The difference between extractants was slightly greater with a soil/solution ratio of 1:8 than of 1:10 (p = 0.03). Our results showed that even when using the same method, changes in the procedure (like soil/solution ratio) may cause different soil-test results and also differences in the relationship between two extracting solutions. Therefore, reported relationships between two methods are only valid for the soils and region where the relationship was developed and should not be extrapolated to other regions, even with similar soils. 相似文献
34.
本文根据变量理论分布对区试中b值及CV值参数的数量分类,提出了适于目前普及推广的查表计算法。在此基础上,对区试品种提出了按主要生产性能指标以量定性的评定分类体系。从而推出可排除主观随意性干扰、较为完整严密的区试汇总模式,并以范例作了运用说明。 相似文献
35.
36.
37.
ASVCP guidelines: quality assurance for portable blood glucose meter (glucometer) use in veterinary medicine
下载免费PDF全文
![点击此处可从《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Karen L. Gerber Kathleen P. Freeman 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2016,45(1):10-27
Portable blood glucose meters (PBGM, glucometers) are a convenient, cost effective, and quick means to assess patient blood glucose concentration. The number of commercially available PBGM is constantly increasing, making it challenging to determine whether certain glucometers may have benefits over others for veterinary testing. The challenge in selection of an appropriate glucometer from a quality perspective is compounded by the variety of analytic methods used to quantify glucose concentrations and disparate statistical analysis in many published studies. These guidelines were developed as part of the ASVCP QALS committee response to establish recommendations to improve the quality of testing using point‐of‐care testing (POCT) handheld and benchtop devices in veterinary medicine. They are intended for clinical pathologists and laboratory professionals to provide them with background knowledge and specific recommendations for quality assurance (QA) and quality control (QC), and to serve as a resource to assist the provision of advice to veterinarians and technicians to improve the quality of results obtained when using PBGM. These guidelines are not intended to be all‐inclusive; rather they provide a minimum standard for management of PBGM in the veterinary setting. 相似文献
38.
39.
40.
Mechanical and Thermal Sensory Testing in Normal Chondrodystrophoid Dogs and Dogs with Spinal Cord Injury caused by Thoracolumbar Intervertebral Disc Herniations
下载免费PDF全文
![点击此处可从《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)