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861.
对5种不同工艺制备的杉木颗粒活性炭的丁烷活性、丁烷工作容量、丁烷持附性与孔结构之间的关系进行了研究.结果表明:丁烷吸附性能与活性炭样品的比表面积、孔容积和孔径分布有着密切联系.对丁烷活性起作用的孔主要集中在1.16~2.00 nm;对丁烷工作容量有显著影响的孔径介于2.0~4.0 nm;对丁烷持附性影响最大的孔分布在0.5~1.0 nm.大孔对整个吸附过程没有什么显著影响,只是作为丁烷分子进入中孔、微孔的输送通道. 相似文献
862.
湿地松粉蚧有效积温及其在国内可能扩散范围的研究 总被引:1,自引:0,他引:1
应用恒温条件下直线回归法,对湿地松粉蚧发育起点温度与有效积温进行研究,结果表明:粉蚧完成1代的发育起点温度为7.8±1.0℃,最适发育温度为24~25℃,有效积温为1042.9±88.4日度;粉蚧向北扩散,在华南地区为年发生4代区,在长江以南地区为年发生3代区,在黄河以南地区为年发生2代区;粉蚧的最适生境在湖南省、江西省中南端区域 相似文献
863.
We studied the nutrient cycle of a planted forest of Pinus tabulaeformis in the Miyun Reservoir Watershed, Beijing. Results show that the total biomass of P. tabulaeformis stands at age 29 in the experimental area is 92627 kg/hm2, and the total nutrient store is 695.17 kg/hm2 including nitrogen (N), phosphorus (P), kalium (K), calium (Ca) and magnesium (Mg). The sequence of their contents in different
organs was given as follows: needle>branch> trunk>root. The annual amount of 85.37 kg/hm2 of five nutrient elements were assimilated by P. tabulaeformis, about 0.34% of the total store in soil, and 3.30% of available nutrient store in soil depth from 0 to 30 cm. The nutrient
annual retention is 35.92 kg/hm2, annual returning 49.46 kg/hm2, the rain input 26.04 kg/hm2 to the five nutrient elements. The parameter absorption coefficient, utilization coefficient, cycle coefficient and turnover
period were cited to describe the nutrient elements cycle characteristic of the planted forest ecosystem of P. tabulaeformis. The absorption coefficient is the ratio of plant nutrient element content to soil nutrient element content, and its sequence
of five nutrient elements was given as follows: N>P>K>Ca>Mg. Utilization coefficient is the ratio of the nutrient element
annual uptake amount to the nutrient element storage in standing crops, and its sequence of five nutrient elements was: Mg>K>
P>N>Ca. The big utilization coefficient means more nutrients stored in the plant. The cycle coefficient is the ratio of the
nutrient element annual return amount to the nutrient element annual uptake amount, its sequence: Ca>N>P>K>Mg. Turnover period
is the ratio of the nutrient storage in the crops to the annual returning, its sequence: Mg>K>P>N>Ca.
__________
Translated from Journal of Beijing Forestry University, 2008, 30(3): 51–56 [译自: 北京林业大学学报] 相似文献
864.
Luozhong Tang Dan Zhao Chunfeng Yan Zhilong Liu Shengzuo Fang Mukui Yu 《Frontiers of Forestry in China》2009,4(2):185-190
The effects of site conditions and cultivation on the growth of sawtooth oak (Quercus acutissima Carr.) plantations were evaluated at the Hongyashan forest farm, in Chuzhou City, Anhui Province, China. The results indicate
that the position on the slope, the amount of gravel and the thickness of the soil were important factors in the growth of
the sawtooth oak. Lower slope positions with small amounts of gravel and a thick soil were better for the growth of this species
than middle slope positions with more gravel and a thin soil. Given the site conditions of the hilly and mountainous areas
in Chuzhou City, the mixed Chinese fir (Cunninghamia lanceolata Hook.) and sawtooth oak forests did not improve forest productivity compared with pure sawtooth oak forests. Both urea and
compound fertilizers promoted the growth of sawtooth oak, as did site preparation and intercropping. Two years after planting,
the height growth of ordinary seedlings with a starting height of 0.6 m was higher than that of supper seedlings with a starting
height of 1.0 m. Compared with planting, the early growth of the coppices was faster, but the later growth of the coppices
was slower.
__________
Translated from Journal of Fujian College of Forestry, 2008, 28(2): 130–135 [译自: 福建林学院学报] 相似文献
865.
In this study, we tested the ability of Baicalin to block Chlamydia trachomatis infection and found that the Baicalin blocked infection of Hep-2 cells. Then, we looked into the expression of RFX5 and CPAF gene in Chlamydia-infected cells. We found that RFX5 and CPAF were up-regulated and down-regulated respectively by Baicalin. Since CPAF is responsible for degrading RFX5, we suggest that CPAF was a primary target of Baicalin and played an important role in regulating RFX5. Our findings demonstrate that Baicalin can inhibit C. trachomatis effectively and therefore, can be considered as potential agents for therapy of Chlamydia infectious diseases. 相似文献
866.
867.
能源植物麻疯树研究进展 总被引:6,自引:0,他引:6
本文主要概述了生物能源树种麻疯树近年国内外在资源分布、毒性和药理活性、生物农药活性、生物柴油、生理生态、培育等方面研究进展,并对其种子丰产技术进行了探讨。 相似文献
868.
869.
The fungitoxic metabolites of Spiraea alpina Pall. were identified using inhibition of Rhizoctonia solani, Gibberella zeae, Pyricularia oryzea and Exserohilum turcicum as an end-point. The major fungitoxic constituent of S. alpina was a new diacylated sugar, structurally elucidated as 6-O-(3′,4′-dihydroxy-2′-methylenbutyryl)-1-O-trans-cinnamoyl-β-D-glucopyranose. This compound could inhibit at 0.1 mg/ml Rhizoctonia solani and Exserohilum turcicum, 87.6% and 63.2%, respectively. 相似文献
870.