全文获取类型
收费全文 | 661篇 |
免费 | 31篇 |
专业分类
林业 | 33篇 |
农学 | 20篇 |
基础科学 | 1篇 |
114篇 | |
综合类 | 49篇 |
农作物 | 104篇 |
水产渔业 | 52篇 |
畜牧兽医 | 232篇 |
园艺 | 8篇 |
植物保护 | 79篇 |
出版年
2023年 | 2篇 |
2022年 | 13篇 |
2021年 | 18篇 |
2020年 | 21篇 |
2019年 | 18篇 |
2018年 | 16篇 |
2017年 | 23篇 |
2016年 | 21篇 |
2015年 | 20篇 |
2014年 | 34篇 |
2013年 | 38篇 |
2012年 | 41篇 |
2011年 | 51篇 |
2010年 | 29篇 |
2009年 | 22篇 |
2008年 | 42篇 |
2007年 | 39篇 |
2006年 | 33篇 |
2005年 | 32篇 |
2004年 | 33篇 |
2003年 | 20篇 |
2002年 | 19篇 |
2001年 | 13篇 |
2000年 | 16篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1994年 | 3篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1965年 | 3篇 |
1964年 | 2篇 |
1963年 | 2篇 |
1956年 | 1篇 |
1948年 | 1篇 |
1947年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有692条查询结果,搜索用时 15 毫秒
691.
Pavani Dulanja Dissanayake Kumuduni Niroshika Palansooriya Mee Kyung Sang Dongyeop X. Oh Jeyoung Park Sung Yeon Hwang Avanthi Deshani Igalavithana Cheng Gu Yong Sik Ok 《Soil Use and Management》2022,38(3):1446-1458
Accumulation of microplastics (MPs) in agricultural environments has caused growing concern in recent years because of its detrimental impacts on soil quality, crop productivity and ecosystem function. This study was conducted to assess the impact of biochar on soil chemical and microbial properties in a MP-contaminated soil under two moisture regimes. Soil was contaminated with 1% (w/w) of low-density polyethylene MPs. Four types of standard biochar, that is, oil seed rape (OSR) biochar produced at 550°C (OSR 550) and 700°C (OSR 700) and soft wood pellet (SWP) biochar produced at 550°C (SWP 550) and 700°C (SWP 700), were applied at a rate of 5% (w/w). The control was maintained without MP addition. The samples were incubated in soil with two moisture regimes, that is, at 30% and 70% of the water holding capacity, and the soil chemical and microbiological properties were assessed after 100 days of incubation. OSR biochar application significantly increased soil pH (8.53–8.81) and electrical conductivity (0.51–0.58 dS/m) in both moisture regimes. The effect of biochar application on soil enzyme activity and microbial community composition did not show a clear trend. However, SWP 700 biochar improved soil enzyme activity compared with that of the control and improved bacterial diversity and evenness compared with those of other biochars, which was attributed to the high surface area available for microbial colonization. Low soil moisture content significantly reduced enzyme activity and bacterial richness even with biochar amendment, except for SWP 550 biochar. This study implies the suitability of biochar for improvement of soil quality in MP contaminated soil under both moisture regimes. However, further long-term studies are needed to get a clear understanding on the impact of different types of biochar on MP-contaminated soil. 相似文献
692.
A Hobart mixer with a pin‐type attachment was used to mix soft wheat flour dough. Power consumption profiles were measured continuously during mixing for 20 min using a current transducer and a data logging system. Experimental variables were quantity of flour (500, 1,000, and 1,500 g of dry wheat flour), water content (43, 45, and 47%, wb), and mixer speed setting (low, medium, and high). The power consumption profiles were evaluated by moving average and spectral analysis. Peaks in the power consumption profiles were located to determine the optimal mixing time. The optimal mixing times were then compared with storage and viscous moduli measured using a dynamic rheometer to assure the maximum strength of wheat dough at the optimal mixing time. Tolerance was determined using the signal amplitude and phase angle data from spectral analysis. Optimal mixing times of various doughs at medium speed ranged from 510 to 850 sec; low and high flour quantities required longer mixing times than medium quantity of flour. The optimal mixing time increased when the moisture content was lowered. Tolerance was affected by mixing speed and moisture content of flour 相似文献