全文获取类型
收费全文 | 590篇 |
免费 | 51篇 |
国内免费 | 87篇 |
专业分类
林业 | 63篇 |
农学 | 79篇 |
基础科学 | 48篇 |
163篇 | |
综合类 | 136篇 |
农作物 | 50篇 |
水产渔业 | 19篇 |
畜牧兽医 | 129篇 |
园艺 | 8篇 |
植物保护 | 33篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 27篇 |
2021年 | 32篇 |
2020年 | 36篇 |
2019年 | 39篇 |
2018年 | 27篇 |
2017年 | 31篇 |
2016年 | 26篇 |
2015年 | 25篇 |
2014年 | 23篇 |
2013年 | 38篇 |
2012年 | 45篇 |
2011年 | 40篇 |
2010年 | 35篇 |
2009年 | 26篇 |
2008年 | 26篇 |
2007年 | 24篇 |
2006年 | 25篇 |
2005年 | 35篇 |
2004年 | 16篇 |
2003年 | 14篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 13篇 |
1999年 | 7篇 |
1998年 | 10篇 |
1997年 | 14篇 |
1996年 | 16篇 |
1995年 | 10篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有728条查询结果,搜索用时 15 毫秒
71.
党海英 《农业装备与车辆工程》2005,(2)
该设备是山东省农业机械科学研究所在充吸收国外先进技术的基础上自行开发设计的型绿色农业制肥设备。生化技术制造有机肥是当前处理秸秆的最途径,利用现代化设备和手段控制生产过程,秸秆或畜禽粪便制造成优质生物有机肥,其原是:用高新技术进行菌种的培养和生产,将粉的秸秆或其它农业废弃物与畜禽粪便按一定例混合后,经机械翻抛、高温堆腐、生物发酵等程,转换成优质有机肥。该设备配置82kW四缸涡轮增压式柴油机,功大、油耗低,行走和工作系统采用世界先进的闭式液压传动,匹配动力强劲,操纵灵活方便,其行走速度和整机高度无级可调,并具有完备… 相似文献
72.
73.
Zhiyao Dong Dalu Li Xiaoxiao Hu Lijun Liang Guocan Wu Siyuan Zeng Erbao Liu Yue Wu Hui Wang Lal Bux Bhanbhro Xiaojing Dang Delin Hong 《Euphytica》2018,214(7):117
Flag leaf angle (FLA) in rice (Oryza sativa L.) is one of the important traits affecting F1 seed production by mechanization. To elucidate the genetic mechanism of FLA and mine favorable marker alleles for F1 seed production in rice, we performed a genome-wide association study using phenotypic data over 2 years and genotypic data of 262 pairs of simple sequence repeat (SSR) markers collected from 441 rice accessions. We detected seven SSR marker loci associated with FLA and four loci were novel. The four newly found loci were RM6266 on chromosome 3, RM348 on chromosome 4, RM258 on chromosome 10 and RM7303 on chromosome 11. We found a total of 27 favorable alleles, of which four, i.e., RM348-130 bp, RM7303-90 bp, RM258-180 bp, and RM4835-230 bp, had phenotypic effects larger than 10°. Nine combinations, which increased FLA by 45.7°–94.7° through pyramiding the favorable alleles contained in seven typical accessions, were predicted. 相似文献
74.
Tran Van Do Phung Dinh Trung Mamoru Yamamoto Osamu Kozan Nguyen Toan Thang Dang Van Thuyet 《Journal of Sustainable Forestry》2018,37(1):1-14
Forest ecosystems can modify the atmospheric CO2 through biomass accumulation mostly in tree stems with diameter at breast height (DBH) ≥ 10 cm. Aboveground biomass increment (ΔAGB), and changes in stand AGB, no. stems and basal area (BA) were calculated from mortality, recruitment, and growth data of tree stems in tropical evergreen broadleaved forest, Central Highland Vietnam. Data were derived from ten 1-ha permanent plots established in 2004, where all stems with DBH ≥ 10 cm were tagged, identified to species, and measured for DBH in 2004 and 2012. In an 8-year duration, the increment was 53 ± 10 stems ha–1, 7.8 ± 0.3 m2 ha–1 for BA and 86.0 ± 4.6 Mg ha–1 for AGB. The stem mortality rate was 0.9% year–1 and the stem recruitment rate was 2.2% year–1. Annual ΔAGB was 10.8 Mg ha–1 year–1, equaling to 5.4 Mg C ha–1 year–1. Of which, tree stems of 35–80 cm DBH classes accounted for 65%. The results indicated that the forest is in stage of carbon sequestration. Any disturbances causing death of 35–80 cm DBH tree stems will much reduce carbon sequestration capacity and it will take a long time for AGB to return to pre-disturbance stage. 相似文献
75.
The potential of informal institutions for marine fisheries management—A case study of a coastal commune in Vietnam 下载免费PDF全文
Dang Bach Nguyen Salim Momtaz Nhung Thi Hong Pham 《Fisheries Management and Ecology》2018,25(4):275-286
The potential of informal institutions for sustainable management of marine fisheries was examined. The study is based on both primary data collected through two group discussions and interviews and secondary information, including material related to fishing gear operation and whale worship. It shows that informal institutions, including fisher groups, fishing community norms, fisher's knowledge and whale worship have potential to strengthen institutional, ecological, social and community aspects of sustainable fisheries development. Although these informal institutions are not able to fix completely all the problems faced by formal institutions, they are able to complement and consolidate formal institutions to manage marine fisheries effectively. The findings of this study suggest it is imperative that formal institutions should be improved simultaneously with informal institutions to enhance current management for sustainable marine fisheries development. 相似文献
76.
77.
78.
79.
Thai Khanh Phong Dang Thi Tuyet Nhung Takashi Motobayashi Dang Quoc Thuyet Hirozumi Watanabe 《Water, air, and soil pollution》2009,202(1-4):3-12
The fate and transport of tricyclazole and imidacloprid in paddy plots after nursery-box application was monitored. Water and surface soil samples were collected over a period of 35 days. Rates of dissipation from paddy waters and soils were also measured. Dissipation of the two pesticides from paddy water can be described by first-order kinetics. In the soil, only the dissipation of imidacloprid fitted to the simple first-order kinetics, whereas tricyclazole concentrations fluctuated until the end of the monitoring period. Mean half-life (DT50) values for tricyclazole were 11.8 and 305 days, respectively, in paddy water and surface soil. The corresponding values of imidacloprid were 2.0 and 12.5 days, respectively, in water and in surface soil. Less than 0.9% of tricyclazole and 0.1% of imidacloprid were lost through runoff during the monitoring period even under 6.3 cm of rainfall. The pesticide formulation seemed to affect the environmental fate of these pesticides when these results were compared to those of other studies. 相似文献
80.
A. K. Dang Suman Kapila Maneesh Purohit Charan Singh 《Tropical animal health and production》2009,41(7):1213-1217
Colostrum samples were collected from 8 Murrah buffaloes on days 1, 2, 3, 4 and 5 after calving. Levels of IgG averaged 54.0 mg/ml
at calving, then decreased significantly (P < 0.01). IgA and IgM on day 1 were 3.22 mg/ml and 5.22 mg/ml, respectively; both
decreased during the first five days after calving. Values of IgA and IgM were higher than those reported in cows. SCC values,
which were high at calving (500 000 per ml), reduced significantly (P < 0.01) on day 2, then decreased slightly until day
5 (180 000 per ml). At calving, macrophages were the most prominent cells in buffalo colostrum, followed by lymphocytes and
neutrophils. Phagocytic activity was 23% at calving and reduced significantly (P < 0.01) to 14% on day 5. Phagocytic index
was highest in the first colostrum, and then decreased non-significantly. 相似文献