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991.
生防细菌防治土传病害的研究进展 总被引:5,自引:0,他引:5
介绍了土传病害危害程度及生防细菌的种类、作用机制、防治土传病害的研究概况,提出了目前利用生防细菌防治土传病害存在的问题及应用前景。 相似文献
992.
993.
994.
李伟 《云南农业大学学报(自然科学版)》2008,2(5):1-4
中国特色社会主义道路的形成是对科学社会主义理论的创新,它为我国社会主义建设和发展提供具有创新意义的重大方略和举措,为社会主义事业更加深入人心和不断进步提供理论依据。 相似文献
995.
996.
HUANG Cheng-lei LUO Xin-ping LI Jian LIANG Wang LIN Yi-feng JIN bo SHEN Wei SHI Hai-ming MA Duan 《园艺学报》2008,24(12):2311-2314
AIM: To observe the regulatory changes of tissue factor (TF),tissue factor pathway inhibitor-1 (TFPI-1) and tissue factor pathway inhibitor-2 (TFPI-2) associated with the formation of atherosclerotic plaque on femoral artery of New Zealand rabbits.METHODS: New Zealand rabbits were fed with high cholesterol diet and received femoral artery balloon injury to establish moderated atherosclerotic plaque animal model.These rabbits were classified into 8 weeks group,10 weeks group and 12 weeks group.The expressions of factor TF,TFPI-1 and TFPI-2 in femoral artery were detected by immunohistochemical methods at 8th,10th and 12th week.The positive areas of the slice were analyzed by semi-quantification system.Fluorescence quantification PCR (FQ-PCR) was used to detect the copies of mRNA of TF,TFPI-1 and TFPI-2 in each group.RESULTS: The expressions of TF,TFPI-1 and TFPI-2 determined by immunohistochemical methods were increased from 8th,10th to 12th week,respectively.In each group,the quantity of mRNA of TF and TFPI-1 at the 8th,10th and 12th week was soared,respectively.In each group,the quantity of mRNA of TFPI-2 did not change in early phase,but decreased at 12th week.CONCLUSION: In the process of the atherosclerotic plaque formation in rabbit femoral artery model,the expressions of TFPI-1 and TFPI-2 proteins are increased.However,the expression of TPFI-1 or TFPI-2 could not stave off the development of plaque formation. 相似文献
997.
Soil organic carbon is a soil property of central importance for soil quality and the global carbon cycle. Studies specifically
aimed at the relationship between the spatial variation of soil organic carbon and environmental factors are few. In this
paper, a typical small watershed named Tongshuang in the black soil region of northeast China, which was subjected to drastic
erosion before 1980 and was managed subtly after 1980, was chosen as a study area. Classical statistic and geostatistic analysis
methods, in combination with a geographic information system (GIS), were used to quantitatively research the spatial variation
characteristics of the soil organic carbon and their relation to the topographic factors and land use. The data on the soil
organic carbon, topographic factors, and land use were obtained by soil sampling and measurements derived from DEM, remote
sensing images, and field investigations, respectively. The classical statistics analysis results indicated that the variability
of the soil organic carbon was moderate (Cv = 0.30). The slope position and land use types were the most discriminating factors. The soil organic carbon content was
the highest in the grassland and lowest in the coniferous forest (P < 0.01). It increased gradually along the slope position
gradients from the interfluve to the toe slope. The geostatistics analysis showed that the soil organic carbon had a strong
spatial correlation. The C0/(C0 + C) was 0.1608, which was mainly induced by structural factors. The mean soil organic content is 2.27% in this watershed.
It is on a very low level in the northern black soil of northeast China. In this small watershed of the eroded black soil
region, the present soil and water conservation measures play an important role in controlling the soil loss. However, the
soil organic carbon’s restoration is unsatisfactory. Nearly three-quarters of the land has worrisome productivity. How to
improve the soil organic carbon content while targeting the soil fertility is a pressing need.
Published in Russian in Pochvovedenie, 2008, No. 1, pp. 44–53.
The text was submitted by the authors in English. 相似文献
998.
回顾联合收割机的发展过程,从结构和功能着手,分析不同时期联合收割机所具有的造型特征,提出了不同时期联合收割机造型的几何模型-"分散"型、"L-长方体"型、"T-长方体"型、"T-曲长方体"型、"T-梯形体"型和"T-曲梯形体"型等,总结其造型演变规律,为设计新型联合收割机造型提供了依据. 相似文献
999.
1983年以来,北京地区几个商品鸭场陆续发生鸭窦炎。一年四季均可发生,冬春季多发。7~15日龄雏鸭易感性最高,发病率高,死亡率低。病鸭主要表现沉郁,打喷嚏,摇头,窦炎和结膜炎。耐过鸭生长缓慢,出栏期延长。病理剖检以呼吸器官尤其是眶下窦的炎性反应为特征。组织学变化主要表现呼吸道粘膜充血、水肿、出血,大量单核细胞、淋巴细胞浸润以及淋巴滤泡反应。 相似文献
1000.
从1995年以来,我市发生了以猪为主的家畜血液支原体病,牛、羊、鹿、犬等动物也有发生,以高热,渐进性贫血,黄疸、孕畜流产等为主要症状,造成家畜生产、繁殖能力低下,肉品品质下降,给我市的畜牧业生产造成极大经济损失。据资料记载,本病1932年最早发现于印度,但过去因其致病性弱而长期被人们忽视,直到1950年确定猪黄胆性贫血是该病原体引起,才逐渐被重视起来。目前,本病已广泛分布于世界许多国家和地区,我国于1981年首先在家兔体中发现该病之后,相继在牛、羊、猪、鹿、犬等动物中查到该病原体,在人群中也证实了该病原体感染的病例。1病原血液… 相似文献