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粉煤灰场复垦地肥力状况及对土壤理化性质的影响 总被引:1,自引:0,他引:1
选择安徽省淮南市上窑镇粉煤灰处置场覆土复垦地为研究区域,测定覆土厚度和土壤剖面各层的容重、pH、含水量、有机质等理化性质,土壤总氮、有效磷、速效钾等养分含量,以及冬小麦抽穗期的生物量,研究粉煤灰处置场复垦土壤理化性质及其与土壤养分的相关性,不同覆土厚度复垦地冬小麦生长的差异性.结果表明,粉煤灰场复垦地土壤总氮含量约0.90 g/kg,有效磷和速效钾含量分别为12~76 mg/kg、114~135 mg/kg,土壤肥力与作物生长状况和自然农业土壤相比差异不显著;除复垦土壤厚度、容重、含水量对有效磷含量影响显著外,其余土壤养分与土壤理化性质和表土厚度的相关性不强. 相似文献
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【目的】研究甜玉米果皮厚度的遗传模式,为甜玉米品质改良和分子标记辅助选择提供理论依据。【方法】以果皮厚度有显著差异的甜玉米自交系T4和T19为亲本配制杂交组合,用主基因+多基因混合遗传模型及P1、P2、F1、B1、B2和F2共6个世代联合分析的方法,对甜玉米果皮厚度性状进行分析。【结果】果皮厚度的最适遗传模型为D-2,即1对加性主基因+加性-显性多基因混合遗传;主基因遗传率大于相应分离世代的多基因遗传率,B1、B2、F2群体的主基因遗传率分别为59.65%,55.17%和65.24%,多基因遗传率分别为37.84%,41.40%和32.65%,主基因的加性效应值为-27.186 4,多基因的加性效应值为0.289 5,显性效应值为5.742 3。【结论】甜玉米果皮厚度以主基因遗传为主,育种中既要重视利用主基因,也要考虑多基因对性状的影响。 相似文献
105.
立地条件对落叶松人工林生长的影响 总被引:1,自引:1,他引:0
通过对日本落叶松(Larix kaempferi)人工林在不同立地条件下的生长调查,结果表明,日本落叶松在生长过程中,受土层厚度、林地位置、立地指数等多方面因素的制约:厚层土胸径年生长量比中层土和薄层土高9.2%~26.7%,树高年生长量高21.8%~44%;生长在N坡,坡度较缓、山地下腹为优;在不同的立地指数级中,生长差异明显,18以上指数级比14~18指数级胸径生长量高25.4%,比14以下指数级胸径生长量高33.8%,树高生长量,18以上指数级比14~18指数级高26.7%,比14以下指数级高36.3%。培育日本落叶松人工林,选择优质立地条件不但可提高林木的生长速度,又能促使林木优质高产。 相似文献
106.
To investigate the effect of wall thickening around cell corners on the tangential Young's modulus of coniferous early wood, tapered beam cell models in which the variation of the cell wall thickness in the axial direction was taken into account were constructed for seven species. Their tangential Young's moduli were compared with the experimental results. The calculated Young's moduli of tapered beam cell models were larger than those of the models composed of the cell walls with uniform thickness, although both models showed almost the same density. For some species the calculated Young's moduli of the models in which the cell wall thickness increased curvilinearly in the axial direction were much closer to the experimental values. The reduction of the radial cell wall deflection due to the increase of the stiffness around cell corners was considered to increase the tangential Young's modulus of a wood cell.This report was presented at the 49th annual meeting of the Japan Wood Research Society, Tokyo, April 1999 相似文献
107.
《Plant Production Science》2013,16(4):280-285
AbstractLodging is a major cause of yield loss in the rice production systems using direct seeding. In this study, several characteristics of 80 F4 breeding lines and 10 check cultivars were examined in connection with lodging resistance to establish a technique suitable for screening a large number of lines efficiently for breeding rice for direct seeding. Experiments were conducted over a 2-year period in puddled wet-fields and in seed pack growth pouches (SPGP). Among the root parameters of SPGP seedlings, only root thickness had a significant positive correlation (r = 0.495**) with pushing resistance, which is the force to bend rice culm to a designated angle and is correlated with lodging resistance. The root thickness of SPGP seedlings was also positively correlated with root thickness in the field at 18 (r = 0.346**) and 30 (r = 0.512**) days after seeding. For selected lines and check cultivars, positive correlations were found between pushing resistance and culm thickness in the field (r = 0.809**), between pushing resistance and root thickness in SPGP (r = 0.694**). Culm length and panicle number were negatively correlated with pushing resistance (r=–0.454**, r=–0.563**, respectively). Among the characteristics related to lodging, root and culm thickness were higher in selected breeding lines than in check cultivars. Grain yield was positively correlated with panicle weight (r = 0.601**) and harvest index (r = 0.586**) but not with panicle number (r=–0.007ns). Thus the low-tillering, panicle-weight type plants with thick roots and culms seem to be suitable for direct seeding. Some promising lines and candidate parental lines for the next crossing cycle for direct seeding were identified. 相似文献
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