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991.
Satoshi Saito 《Journal of Forest Research》2002,7(3):137-143
The effects of a typhoon on forest dynamics and the response of major tree species were studied in a warm-temperate evergreen
broad-leaved forest in southwestern Japan. The strongest typhoon on record (T9313) passed through this region in 1993. Return
periods of typhoons over 30 ms−1 in instantaneous wind velocity and T9313 were estimated to be 2.2 and 104.5 years, respectively. Approximately 10% of all
stems suffered some damage from T9313 and annual stem mortality rose from 1.3 to 2.7%. The estimated period that the number
of stems would fall below 10% of the initial was four years shorter with T9313-class typhoons than without them. Thus, the
disturbance by T9313 was not catastrophic at the site although T9313 was an episodic typhoon. The short-term responses of
major tree species to T9313 were classified into four types: 1) blunt-response type with little decrease and recruitment of
stems in the DBH ≥ 5 cm class (Distylium racemosum), 2) retreat type with larger decrease than recruitment (e.g. Quercus acuta), 3) sharp-response type with a large decrease and much recruitment (e.g. Cinnamomum japonicum), and 4) advance type with less decrease than recruitment (Eurya japonica). Among the four regeneration types classified by previous studies (climax, light-demanding, subcanopy, and few-sapling),
the climax and few-sapling types each showed a specific short-term response, the blunt-response and retreat types, respectively,
that explains one aspect of the regeneration strategies of each type. On the other hand, the light-demanding or sub-canopy
type showed multiple short-term responses, indicating that each regeneration type contains species with various regeneration
strategies.
In this paper, I analyzed data from the database that was compiled by the Aya Research Team. 相似文献
992.
第二代杉木林养分动态研究 总被引:3,自引:0,他引:3
根据连续定位观测所取得的数据,对4个小集水区第二代10年生杉木人工林生态系统中的养分循环进行了研究.结果表明.集水区由降水输入的N、P、K、Ca、Mg等营养元素总计为59.285kg/hm2a,径流输出为38.938kg/hm2a,净积累量为20.347kg/hm2a.与该林分7年生时相比,净积累量提高了7.2%,说明集水区第二代杉木林生态恢复处于进展的变化过程. 相似文献
993.
南方红豆杉扦插繁殖技术研究 总被引:6,自引:0,他引:6
2003~2004年应用2年生南方红豆杉幼苗进行扦插试验研究,结果表明:不同时间扦插的插穗生根时间最多相差2个月,2月中旬至3月中旬为最适宜扦插季节,扦插后3~5个月的生根率高于其它月份。用河沙与红泥作基质扦插,在不同季节扦插中以河沙作基质的生根效果比红泥的好。用生根剂处理有利于插穗提早生根及增加生根数量,以冬季及早春应用的效果较为明显,应用生根剂的插穗在扦插3~5个月后的生根率和生根数量与对照比有显著差异。不同类型插穗的扦插生根率在不同月份扦插的结果不同,但其差异不显著。 相似文献
994.
995.
在科尔沁沙地证明低覆盖度行带式固沙林具有显著的防风效果后,进一步对雨养条件下杨树(赤峰-36号)固沙林的密度、配置及林木生长过程与林龄的动态关系进行研究.结果表明: 1)1~5 a林木的生长基本不受密度的影响,密度大单位面积材积量大;6~11 a是密度对林木生长的显著影响阶段,杨树固沙林的胸径、株高和材积量的增长率随林龄增大而逐年加快;大约在11 a之后趋于稳定;单位活立木蓄积最大(153.39 m3·hm-2)的固沙林密度是825株·hm-2,其他密度按蓄积大小排序依次为540株·hm-2、420株·hm-2和1 215株·hm-2;2)边缘林木的平均胸径和单株材积量分别比林内高20%~70%和90%~260%,且低密度林分的边缘林木的生长优势比高密度林分边缘林木的生长优势更加明显;3)同密度(500株·hm-2)13 a的一行一带式固沙林,其胸径、树高和材积量分别比等株行距的片林高37.4%、17.4%和81%;而10 a的两行一带式的胸径、树高和材积量分别比等株行距的片林高19.8%、16.2%和64.8%,说明行带式配置还具有生物生产力优势. 相似文献
996.
第2代杉木人工林地土壤微生物数量与土壤因子的关系 总被引:14,自引:0,他引:14
根据定位观测数据,对湖南会同第2代杉木人工林地土壤微生物数量与土壤因子的关系进行研究.结果表明:杉木人工林地土壤微生物数量以山洼最多,山坡次之,山脊最少;同一立地类型中,0~20 cm土层中微生物数量最多,20~40 cm次之,40~60 cm最少;在同一立地类型中,微生物总数、细菌的数量秋季最高,冬季最低,而真菌和放线菌的数量夏季最高,秋冬两季最低;同一立地类型的板栗林地土壤微生物总数高于杉木人工林地;微生物总数与土壤含水率呈极显著线性正相关(P<0.01),细菌、放线菌的数量与土壤含水率呈显著线性正相关(P<0.05),真菌的数量与土壤含水率不具有相关性(P>0.05);细菌、真菌、放线菌的数量和微生物总数与10 cm处土壤温度不具有相关性(P>0.05);细菌、真菌的数量和微生物总数与土壤有机碳含量、全氮含量呈极显著线性正相关(P<0.01),放线菌的数量与土壤有机碳含量、全氮含量呈显著线性正相关(P<0.05).土壤温度、土壤含水率、土壤有机碳含量及全氮含量对杉木人工林地土壤微生物数量的贡献率为60%~70%. 相似文献
997.
《中国林业科技(英文版)》2009,(2)
As an emerging industry,China's wood floor industry dates back to the early 1980s. Despite a late start,it has developed rapidly during the last 20 years.The past decades have witnessed great changes in China's wood floor industry.With high quality,many products"made in China"are available widely abroad nowadays.Current global economic shocks,however,affect China's domestic real estate sector;hence the falling domestic sales of wood floor.The paper aims to identify the current situation of floor industry... 相似文献
998.
999.
Current silvicultural treatments in beech forests are aimed at achieving thick logs without discoloured hardwood. Therefore
intensive thinning is applied already in younger stands with the objective of large-sized trunks at an age of 100 years. However,
this approach bears the risk that dead wood structures and broken trees are completely removed from the forest. The impact
of three different silvicultural management intensity levels on wood-inhabiting fungi over decades was investigated in a large
beech forest (>10,000 ha) in southern Germany in 69 sampling plots: A Intensive Thinning and Logging with high-value trees,
B Conservation-Oriented Logging with integration of special structures such as dead wood and broken trees and C Strict Forest
Reserves with no logging for 30 years. The analysis of community showed marked differences in the fungus species composition
of the three treatments, independent of stand age. The relative frequencies of species between treatments were statistically
different. Indicator species for naturalness were more abundant at sites with low silvicultural management intensity. Fomes fomentarius, the most common fungus in virgin forests and strict forest reserves, is almost missing in forests with high-management intensity.
The species richness seemed to be lower where intensive thinning was applied (P = 0.051). Species characteristic for coarse woody debris were associated to low management intensity, whereas species with
a significant preference for stumps became more frequent with increasing management intensity. A total amount of dead wood
higher than 60 m3/ha was found to enable significantly higher numbers of species indicators of naturalness (P = 0.013). In conclusion, when applying intensive silvicultural treatment, the role of dead wood needs to be actively considered
in order to maintain the natural biocoenosis of beech forests. 相似文献
1000.
广州市近郊帽峰森林公园的基本功能定位为生态、科研、游憩和服务。据此提出了突出自然野趣,以人为本,促进人与自然的融合、沟通为内容的规划构想。 相似文献