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911.
912.
侧耳与香菇属间原生质体融合育种研究 总被引:5,自引:1,他引:4
侧耳、香菇皆属四极性异宗结合食用菌,其异核双核菌丝体均具“锁状联合”形态标记。本研究以PEG-Ca~(++)为诱导剂,以紫孢侧耳和香菇Cr-20的原生质体再生单核体为亲株,进行侧耳与香菇的属间原生质体融合,结果从1022个融合再生体中镜检出16个具锁状联合遗传标记的融合株。对1~4号融合株与亲株进行的拮抗反应、双单交配、过氧化物同功酶谱分析及菇形特征对比皆证明融合株确具双亲杂合体特征。出菇验证表明,融合株菌丝体长速均快于亲株,出菇期早,菇产量近于或高于亲株侧耳的水平。 相似文献
913.
稻曲病在国内外均有发生,危害愈趋严重:除了降低水稻产量、影响稻米品质外,人、畜食用菌粉过量均有毒害作用。从高产、优质、低(无)毒、低成本方面考虑,认为选育和利用抗病品种是解决生产上稻曲病危害最适宜的途径.本文重点阐述了品种抗性的鉴定方法、抗病品种的选育和利用方法。 相似文献
914.
(Research Group of Stable High Output of Wild Laurel Honey by Chinese Bees Guizhou Province) 《中国蜂业》1996,(2):3-6
在贵州锦屏进行的中蜂越夏及秋繁试验表明,4框以上的群势越夏较为安全。越夏期间每框足蜂约需补喂白糖1.5公斤。越夏后,蜂群群势约下降1/3左右。蜂群在越夏期间飞逃的主要原因是缺蜜及巢虫危害。当地中蜂在秋季大流蜜初期发生分蜂,分蜂群势均为8框足蜂以上,7框左右不分群。为控制不同起繁群势的蜂群在秋季大流蜜初期正好繁殖到7框左右,不致因分蜂影响秋冬蜜的采集,应分期起步秋繁。根据本试验所建秋季起繁群势(x)与达7框群势所需繁殖天数(y)之间的回归直线方程推算,在起繁群势为1~5框蜂量时,最适的秋繁开始期,1框群为7月31日,2框群8月10日……蜂群的基础群势每增加一框,则秋繁开始期应相应推迟10~11天。 相似文献
915.
Breeding planning and variety valuation can be supported only if weighting factors for the economically relevant performance traits are available. In plant breeding they are necessary for the calculation of selection indices as well as for the comparison of varieties and for quantifying the monetary impact of breeding progress. In this article the economic weights for the most important performance traits of sugar beet are calculated from the farmer's, the sugar factory's, and the national economy's point of view. Based upon economic weights for beet yield, sugar content, potassium, sodium, and ammo nitrogen content, a total of 19 varieties was compared with regard to physical and economic performance. The investigation shows that “best” and “worst” varieties differ in gross margin per ha by 270.— to 330.— DM. Indications were given for possibilities and limitations of the application of economic weights in breeding planning. 相似文献
916.
Summary The use of Cruden's index (1977), for studying okra sexual reproductive allocations, indicates a facultative autogamy mode. The purpose of the research described is to obtain more accurate information on the self-fertilization process. For this, self-pollen grain germination was stopped at different times of the day. Twelve varieties of Abelmoschus esculentus were used. Self-fertilization kinetics—expressed by the setting rate—displayed an increase between 7.00 to 16.00 hr. Study of obtained progenies, by stimulated allogamy, confirmed the process and showed that allo-pollen grains deposited on a stigma after midday had only a very little chance of contributing to fertilization. As a result, the polymorphism of the flower structure and particularly the distance between anther and stigmas, insect types and movement habits play major roles in governing okra allogamy. We also show that self-fertilization kinetics can be used to improve controlled hybrid production. 相似文献
917.
Public plant breeders, in seeking the most efficient means of achieving their objectives, face decisions on the appropriate breeding strategy and program structure to use. This paper reports an analysis comparing the changes in costs and benefits from the introduction of recent technology enabling testing for flour and dough properties to be carried out on small samples in the early-generations of a wheat breeding program in Australia. The average costs of a suite of early-generation tests are higher than the equivalent (unreplicated) yield testing. The analysis presented confirms that the introduction of early-generation quality testing leads to a faster rate of expected progress in quality, but a slower rate of progress in yield. The estimated market value of an increase in yield is greater than that for quality, based on current market information. Thus, the result of incorporating early-generation quality testing is higher costs and lower expected returns, so that there is a loss of community welfare from using early-generation quality testing if the resultant cultivar is released from each program. However, the probability of the higher-quality cultivar being released for commercial cultivation is greater, so that recognition of the probability of release means that there may be net gains from the use of early-generation quality testing. 相似文献
918.
概述了80年代发展起来的新的育种途径—水稻穿梭育种法研究的进展。在理论上初步探明了水稻穿梭育种选择的有效性及其选择规律,在实践中已育成一批各具特色的新品种,有的并用于生产。”同时展望了发展前景。 相似文献
919.
本文对10种珍稀树种的采种期、采种方法、种子处理、贮藏方法、育苗方法以及幼苗形态特征等进行了较为系统的介绍。 相似文献
920.