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排序方式: 共有589条查询结果,搜索用时 31 毫秒
81.
水稻试验小区边际效应的估算 总被引:8,自引:0,他引:8
本文对水稻试验小区各行实际产量与行的对应关系进行曲线拟合,从而获得可用来评估小区边际效应的模拟曲线方程,根据方程提供的参数δ可进行小区边际效应的评估。如在产量潜力评估的
各级试验中加以采用,将极大地提高试验结果的准确性。 相似文献
82.
水稻大面积高产综合配套技术研究开发与示范1996年度课题攻关报告 总被引:1,自引:0,他引:1
湖南省课题攻关协作组 《中国水稻科学》1998,12(Z1):1-3
总结了1996年水稻大面积高产综合配套技术研究开发与示范的进展。 相似文献
83.
Olivia Oberholster 《The Canadian veterinary journal. La revue veterinaire canadienne》2021,62(12):1341
A 4-year-old neutered male St. Bernard-mastiff crossbred dog showed clinical signs of lethargy and anorexia after being administered phenobarbital for the treatment of idiosyncratic seizures. A complete blood (cell) count revealed pancytopenia. Auto-agglutination and Coombs tests were negative suggesting that an immunemediated cause was unlikely; therefore, an idiosyncratic reaction to phenobarbital was suspected. Supportive care and control of seizures with zonisamide was initiated and clinical signs improved. Blood values were monitored closely and returned to normal after 3 wk. 相似文献
84.
85.
带有黄绿叶色标记的香型籼稻不育系形态特征及开花习性 总被引:1,自引:0,他引:1
我们对3个含有黄绿叶色标记的香型籼稻不育系黄标1A、黄标2A、黄标3A和正常绿叶不育系Ⅱ-32A、G46A的形态特征及开花习性进行了调查分析。结果表明:黄标1A、黄标2A、黄标3A不育系同正常叶色不育系Ⅱ-32A、G46A的叶色差异显著,易肉眼识别,其外部形态特征为植株叶片及颖壳呈黄绿色,黄标A株系株高(41.5~56.5cm)比Ⅱ-32A(59.5cm)、G46A(60.4cm)要矮,以黄标3A的播始期85d比Ⅱ-32A短8d、比G46A长7d,穗长、穗平着粒与Ⅱ-32A、G46A相当,千粒重比Ⅱ-32A、G46A高出1.8g和1.47g,其中颖尖、叶鞘、叶耳及叶片边缘呈紫红色。黄标1A、黄标2A、黄标3A不育系的柱头外露率、张颖角度都高于Ⅱ-32A和G46A,柱头生活力供试不育系间存在着生理功能的差异。包颈长度Ⅱ-32A最长,黄标1A、黄标2A、黄标3A与G46A相当;半包颈长度黄标1A、黄标2A和黄标3A相当(3.0~3.5cm)、而Ⅱ-32A最长(5.0cm)、G46A次之(4.5cm)。黄标1A、黄标2A、黄标3A不育系的开花动态相似,曲线呈双峰型,开花高峰为开花后的第2~5天,与Ⅱ-32A的开花动态相似,但Ⅱ-32A有明显的低谷,而G46A曲线呈单峰型。不同不育系所开的颖花数并不一样,以开花第8天统计开花数以黄标2A最多,其次是黄标3A,黄标1A和对照Ⅱ-32A开花数相同,而G46A到第8天开花结束。黄标1A、黄标2A的开花盛期与Ⅱ-32A一致,为开花后第5天,而黄标3A与G46A一致,为4d。参试不育系每天上午10:00时初花、11:00~12:30时为开花盛期,只有G46A表现出迟花特性。 相似文献
86.
ZHAN Xiao-deng ZHOU Hai-peng CHAI Rong-yao ZHUANG Jie-yun CHENG Shi-hua CAO Li-yong Chinese National Center for Rice Improvement State 《水稻科学》2012,19(1):29-35
Genetic improvement is one of the most effective strategies to prevent rice from blast and bacterial blight(BB) diseases,the two most prevalent diseases jeopardizing rice production.Rice hybrids with dural resistance to blast and BB are needed for sustainable production of food.An incomplete diallele design resulted in 25 crosses between five blast and five BB resistant germplasm accessions.Only one pair of parents,DH146 × TM487,showed polymorphism for all the markers to identify one blast resistance gene Pi25 and three BB resistance genes,Xa21,xa13 and xa5,thus it was used in the marker-assisted selection(MAS).F2 individuals of DH146 × TM487 were genotyped using flanking markers of RM3330 and sequence tagged site(STS) marker SA7 for Pi25.The resistant F2 plants with Pi25 were used for pyramiding BB resistance genes Xa21,xa13 and xa5 identified by the markers pTA248,RM264 and RM153,respectively in subsequent generations.Finally,after selection for agronomic traits and restoration ability among 12 pyramided lines,we acquired an elite restorer line,R8012 including all four target genes(Pi25+Xa21+xa13+xa5).Hybrid Zhong 9A/R8012 derived from the selected line showed stronger resistance to blast and BB,and higher grain yield than the commercial checks uniformally in experimental plots,2007 state-wide yield trial and 2008 nation-wide yield trial.This study provides a paradigmatic example to show that MAS is a practically feasible tool in effectively pyramiding multiple resistance genes.The resultant restoring line and its hybrid would play an important role in securing rice production in China. 相似文献
87.
Jonathan C. P. Reum Timothy E. Essington Correigh M. Greene Casimir A. Rice Patrick Polte Kurt L. Fresh 《Fisheries Oceanography》2013,22(4):324-336
Variation in growth and body size during critical life history stages can have important implications for life history schedules and survivorship. For Pacific herring (Clupea pallasii), there is still debate as to whether juvenile body size is governed by density‐dependent or ‐independent processes and few have evaluated whether the relative importance of either process shifts over the course of early ontogeny. We used a unique data set consisting of seasonal measurements of abundance, body size, and spatial distribution within a semi‐enclosed basin of Puget Sound (Washington State, U.S.A.) to measure the relative importance of temperature and cohort abundance on body size at distinct time periods, and evaluated whether density‐dependent habitat shifts might be responsible for density‐dependent growth. Over the 9 years of sampling (2001–2010) midsummer body size was positively related to temperatures experienced during the egg/yolk sac and larval stages and unrelated to cohort abundance. However, fall body size was negatively correlated with abundance and uncorrelated with both midsummer body size and temperature, indicating a shift from density‐independent to density‐dependent control over the course of the growing season. Thus, density‐dependent effects may supplant density‐independent effects exhibited early in herring life history. Our data on spatial distributions of herring and their zooplankton prey indicate that density‐dependent reductions in growth may be explained by density‐dependent habitat shifts that lead to reduce overlap of herring with zooplankton. Evidence of density‐dependent growth in marine fish populations is often attributed to exploitative competition, but our results suggest that these patterns may partly be mediated by density‐dependent distribution expansions in to prey‐poor habitat. 相似文献
88.
[目的]构建两系不育系水稻P88S育性转换的积温模型。[方法]对2005年和2006年P88S在海南育性转换的试验数据进行分析。[结果]发现P88S在气温在26~28℃之间的可育性是由温度的绝对值和温度的累积效应决定的,并得到了1个基于双稳态的温度累积效应模型。[结论]利用积温模型可以有效地说明两系不育系春秋季育性转换温度的不对称性,即从可育转换为不育需要更高的温度,从不育转换为可育则需要更低的温度,并说明影响水稻育性的因素可能存在累加效应。 相似文献
89.
土壤添加沼渣对温室气体排放及小麦生长的影响 总被引:1,自引:1,他引:0
Liliana PAMPILLÓN-GONZÁLEZ Marco LUNA-GUIDO Victor Manuel RUÍZ-VALDIVIEZO Olivia FRANCO-HERNÁNDEZ Fabián FERNÁNDEZ-LUQUE NO Octavio PAREDES-LÓPEZ Gerardo HERNÁNDEZ Luc DENDOOVEN 《土壤圈》2017,27(2):318-327
Digestate, the product obtained after anaerobic digestion of organic waste for biogas production, is rich in plant nutrients and might be used to fertilize crops. Wheat(Triticum spp. L.) was fertilized with digestate, urea, or left unfertilized and cultivated in the greenhouse for 120 d. Emissions of greenhouse gasses(carbon dioxide(CO_2), methane(CH_4), and nitrous oxide(N_2O)) were monitored and plant growth characteristics were determined at harvest. The digestate was characterized for heavy metals, pathogens, and C and N mineralization potential in an aerobic incubation experiment. No Salmonella spp., Shigella spp., or viable eggs of helminths were detected in the digested pig slurry, but the number of faecal coliforms was as high as 3.6 × 10~4colony-forming units(CFU) g-~(1)dry digestate. The concentrations of heavy metals did not surpass the upper limits established by US Environmental Protection Agency(EPA). After 28 d, 17% of the organic C(436 g kg~(-1)dry digestate) and 8% of the organic N(6.92 g kg~(-1)dry digestate)were mineralized. Emissions of CO_2 and CH_4 were not significantly affected by fertilization in the wheat-cultivated soil, but digestate significantly increased the cumulative N_2O emission by 5 times compared to the urea-amended soil and 63 times compared to the uncultivated unfertilized soil. It could be concluded that digestate was nutrient rich and low in heavy metals and pathogens, and did not affect emissions of CH_4 and CO_2 when applied to a soil cultivated with wheat, but increased emission of N_2O. 相似文献
90.
HUANG Qi-na # YANG Yang SHI Yong-feng CHEN Jie WU Jian-li State Key Laboratory of Rice Biology/Chinese National Center for Rice Improvement China National Rice Research Institute Hangzhou China College of Life Environmental Sciences Hangzhou Normal University Hangzhou 《水稻科学》2010,17(4):247-256
Many rice spotted-leaf(spl) mutants are ideal sources for understanding the mechanisms involved in blast resistance,bacterial blight resistance and programmed cell death in plants.The genetic controls of 50 spotted-leaf mutants in rice have been characterized and a few spotted-leaf genes have been isolated as well.This article reviews the origin,genetic modes,isolation and characterization of spotted-leaf genes responsible for their phenotypes,and their resistance responses to main rice diseases. 相似文献