全文获取类型
收费全文 | 4681篇 |
免费 | 215篇 |
国内免费 | 279篇 |
专业分类
林业 | 437篇 |
农学 | 616篇 |
基础科学 | 167篇 |
381篇 | |
综合类 | 1659篇 |
农作物 | 908篇 |
水产渔业 | 165篇 |
畜牧兽医 | 454篇 |
园艺 | 147篇 |
植物保护 | 241篇 |
出版年
2024年 | 16篇 |
2023年 | 62篇 |
2022年 | 148篇 |
2021年 | 169篇 |
2020年 | 205篇 |
2019年 | 222篇 |
2018年 | 125篇 |
2017年 | 157篇 |
2016年 | 198篇 |
2015年 | 171篇 |
2014年 | 257篇 |
2013年 | 289篇 |
2012年 | 370篇 |
2011年 | 338篇 |
2010年 | 270篇 |
2009年 | 258篇 |
2008年 | 189篇 |
2007年 | 244篇 |
2006年 | 217篇 |
2005年 | 174篇 |
2004年 | 145篇 |
2003年 | 120篇 |
2002年 | 99篇 |
2001年 | 107篇 |
2000年 | 95篇 |
1999年 | 58篇 |
1998年 | 66篇 |
1997年 | 44篇 |
1996年 | 43篇 |
1995年 | 37篇 |
1994年 | 42篇 |
1993年 | 25篇 |
1992年 | 37篇 |
1991年 | 36篇 |
1990年 | 30篇 |
1989年 | 26篇 |
1988年 | 20篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 2篇 |
1984年 | 13篇 |
1983年 | 2篇 |
1982年 | 9篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1962年 | 3篇 |
1956年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有5175条查询结果,搜索用时 46 毫秒
41.
Kanae SHIOKAWA Chandika D. GAMAGE Nobuo KOIZUMI Yoshihiro SAKODA Kenta SHIMIZU Yoshimi TSUDA Kumiko YOSHIMATSU Jiro ARIKAWA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(2):221-230
The applicability of the recombinant LipL32 for serodiagnosis of leptospiral infection in field rodents was
assessed in this study. An immunodominant region of LipL32 was determined by monoclonal antibodies, and then,
truncated LipL32 (tLipL32) was designed to contain the region (87–188th amino acid). The tLipL32 was compared
between two recombinant expression hosts Escherichia coli and Pichia
pastoris in ELISA. With field rat sera, tLipL32 expressed by P. pastoris
(tLipL32p) had high antigenicity without background reactions, while tLipL32 expressed by E.
coli (tLipL32e) showed high background reactions, which were reduced by pre-adsorption of sera with
E. coli. To evaluate tLipL32-ELISA, field rat sera were tentatively divided into a
Leptospira infection positive (12 sera) and a negative group (12 sera) based on the results
from flaB gene PCR of kidney samples and WB with whole Leptospira cell.
Consequently, the sensitivity of tLipL32p-ELISA for field rat sera was 83% . A similar result was obtained
from tLipL32e-ELISA with adsorbed sera, (92%). However, sensitivity of tLipL32e-ELISA using sera without an
adsorption treatment was 50%. Regardless of the expression host, tLipL32-ELISA had 100% specificity and
sensitivity in experimentally infected laboratory rats. These results suggest that recombinant LipL32
expressed by P. pastoris is more applicable for serodiagnosis in field rats due to a lack of
background reaction. 相似文献
42.
Lindsay M. Clontz Anni Yang Sarah M. Chinn Kim M. Pepin Kurt C. VerCauteren George Wittemyer Ryan S. Miller James C. Beasley 《Pest management science》2023,79(10):3819-3829
Background
Data on the movement behavior of translocated wild pigs is needed to develop appropriate response strategies for containing and eliminating new source populations following translocation events. We conducted experimental trials to compare the home range establishment and space-use metrics, including the number of days and distance traveled before becoming range residents, for wild pigs translocated with their social group and individually.Results
We found wild pigs translocated with their social group made less extensive movements away from the release location and established a stable home range ~5 days faster than those translocated individually. We also examined how habitat quality impacted the home range sizes of translocated wild pigs and found wild pigs maintained larger ranges in areas with higher proportion of low-quality habitat.Conclusion
Collectively, our findings suggest translocations of invasive wild pigs have a greater probability of establishing a viable population near the release site when habitat quality is high and when released with members of their social unit compared to individuals moved independent of their social group or to low-quality habitat. However, all wild pigs translocated in our study made extensive movements from their release location, highlighting the potential for single translocation events of either individuals or groups to have far-reaching consequences within a much broader landscape beyond the location where they are released. These results highlight the challenges associated with containing populations in areas where illegal introduction of wild pigs occurs, and the need for rapid response once releases are identified. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献43.
44.
45.
46.
47.
48.
生长健壮的花生根瘤在CLS培养基上诱导出愈伤组织,形成愈伤组织的频率达到26.5-46.6%。瘤愈伤组织能多次继代,生长良好,在分化培养基D-57和D-59上已分化形成了根,其生根频率分别为56%和78%。显微观察表明,愈伤组织分化的具有正常根的解剖结构。 相似文献
49.
播期对花生光合性能与产量影响的研究 总被引:5,自引:0,他引:5
以青花5号花生品种为材料,在田间地膜覆盖栽培条件下,系统研究了不同播期对花生光合性能和产量的影响。结果表明:不同播期对花生功能叶片光合性能和产量均有显著影响,叶面积系数、叶绿素SPAD值、净光合速率、产量均以4月30日和5月10日播种的较高,过早和过晚播种均不利于功能叶片光合性能和产量的提高。研究认为,在本试验条件下,5月上旬是花生获得高产的最佳播期。 相似文献
50.
花生壳残渣制备活性炭及吸附性能测定 总被引:1,自引:0,他引:1
用提取黄酮后废弃的花生壳做原料,选择不同的活化剂在一定温度下制备活性炭,并且测定其吸附性能。结果表明:磷酸作为活化剂时活性炭产率最高,达39.5%;当炭化温度为500℃、活化剂为氢氧化钾或磷酸、活化剂浓度为10%时,碘吸附值最高,为966.7mg/g;当炭化温度为500℃、活化剂浓度为10%时,几种活化剂制备出来的活性炭亚甲基蓝脱色力均达到40mL/g左右;与几种市售活性炭比较,花生壳活性炭碘吸附值能够满足市场需要,但是亚甲基蓝脱色力偏低;相同条件下,盐作为活化剂所制备出的活性炭对镍离子的吸附能力比较稳定。 相似文献