全文获取类型
收费全文 | 52篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
林业 | 7篇 |
15篇 | |
综合类 | 2篇 |
农作物 | 2篇 |
畜牧兽医 | 29篇 |
园艺 | 1篇 |
出版年
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2012年 | 3篇 |
2011年 | 7篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1985年 | 1篇 |
1928年 | 1篇 |
1902年 | 1篇 |
排序方式: 共有56条查询结果,搜索用时 250 毫秒
1.
Karl Maximilian Müller 《Forstwissenschaftliches Centralblatt》1928,50(6):177-192
Ohne Zusammenfassung 相似文献
2.
Schulte Maximilian Jonsson Ragnar Hammar Torun Stendahl Johan Hansson Per-Anders 《European Journal of Forest Research》2022,141(5):865-866
European Journal of Forest Research - 相似文献
3.
Schulte Maximilian Jonsson Ragnar Hammar Torun Stendahl Johan Hansson Per-Anders 《European Journal of Forest Research》2022,141(5):845-863
European Journal of Forest Research - Climate change mitigation trade-offs between increasing harvests to exploit substitution effects versus accumulating forest carbon sequestration complicate... 相似文献
4.
Frauke Kleemann Maximilian von Fragstein Barbara Vornam Annika Müller Christoph Leuschner Andrea Holzschuh Teja Tscharntke Reiner Finkeldey Andrea Polle 《European Journal of Forest Research》2011,130(5):707-716
Knowledge on phenological, morphometric, and phytochemical variation of local progenies of European aspen (Populus tremula, L.) is limited. The goal of this study was to characterize variation in growth and ecologically important leaf properties
in aspen full-sib families in relation to interacting organisms (mycorrhiza, endophytes, and insects) and to determine whether
these interactions were affected by soil application of a systemic fungicide. In local progenies, within-family variation
of neutral molecular genetic markers (nuclear microsatellites) was higher than between families. Significant variation in
growth, production of phenolic defensive compounds and other phytochemical leaf traits was found between families. Phenolic
compounds showed clear negative correlation with generalist herbivores, but did not result in negative trade-off with biomass
production. Differences in mycorrhizal colonization were not found among full-sib families and application of a systemic fungicide
suppressed neither mycorrhizal colonization nor infestation with insects. However, a strong suppression of endophytes occurred,
whose long-term consequences may require attention when fungicides are used in agroforestry plantations. 相似文献
5.
12 cattle microsatellite DNA markers were used for establishing the paternity of 4 Datong Yak calves.The results indicated that paternity can be assigned by use of exclusion method directely when the mother is clearly known and data of all likely sires were obtained. The more the alleles of a locus possessed, the more effectively the paternity can be assigned. Not only the microsatellite DNA marker is a promising tool in establishment of yak detail pedigrees, but also can provide us information of reproductive efficiency of the bull(s) based on the numbers of calves it produced in the herd, which will be useful in speeding up the processes of yak genetics improvement. 相似文献
6.
中国家鸡和红色原鸡mtDNA控制区遗传多态性及系统进化分析 总被引:10,自引:0,他引:10
通过线粒体DNA控制区的结构和多态性来研究中国家鸡和红色原鸡的遗传多态性与系统进化。测定14个中国地方鸡种和红色原鸡2个亚种的256个个体线粒体DNA控制区部分序列约560bp,结果表明,A、C、G、T这4种核苷酸的平均比例分别为25.∞%、37.40%、4.40%和33.20%。共发现44个变异位点,约占分析位点总数的7.86%,没有观测到插入/缺失,颠换和转换之比为0.13;共具有32种单倍型,9种为共享单倍型;16个群体内单倍型多样度从0到0.964,单倍型变异度总体为0.909±0.014,整体的平均核苷酸差异数为7.276,核苷酸多样度为1.851%。群体间核苷酸分歧度(Dxy)在0.747%~3.125%之间变化,核苷酸净遗传距离(Da)为0.015%~2.633%。16个群体表现出较高水平的遗传多态性,群体间表现出显著的遗传分化。群体遗传多态性和亲缘关系分析表明,一些中国家鸡的群体(如固始鸡和仙居鸡)起源于泰国红色原鸡Gallus gallu sgallus亚种,一些中国家鸡的群体(如茶花鸡和藏鸡等)起源于中国红色原鸡Gallus gallus spadiceus亚种,在一些中国地方鸡种还同时具有这2种红色原鸡的遗传贡献;认为中国家鸡起源于泰国或单纯起源于中国的观点都是不全面的。 相似文献
7.
Maximilian Estevan Oliveira Jssica Campanholi Roberta Lima Cavalcante Felipe Silveira Moreno Edson Hideaki Yoshida Murilo Melo Juste Dini lvio Franco de Camargo Aranha Jos Carlos Cogo Lourdes Dias Stephen Hyslop Denise Grotto Valquíria Miwa Hanai‐Yoshida Yoko Oshima‐Franco 《Journal of Veterinary Emergency and Critical Care》2020,30(3):286-294
8.
Maximilian Wentzel Tim Koddenberg Holger Militz 《Wood material science & engineering》2020,15(4):223-228
ABSTRACT Eucalyptus nitens specimens were thermally modified under open and closed systems. The anatomical characteristics from selected modifications that presented similar mass losses were investigated by analyzing images taken from scanning electron microscopy, transmission light microscopy, and X-ray micro-computed tomography. Wood cell wall thickness, fiber, and lumen area were measured and compared to unmodified specimens, and the crack formation after modification was also analyzed. There was only a slight decrease in the measured characteristics when compared to unmodified specimens. The wood cell wall thickness was less affected than the fiber and lumen areas, and both modifications presented similar crack formations. Overall, there were no significant differences between open and closed system modifications in the anatomical structure. 相似文献
9.
Choice of breeding stock,preference of production traits and culling criteria of village chickens among Zimbabwe agro-ecological zones 总被引:3,自引:3,他引:0
Muchadeyi FC Wollny CB Eding H Weigend S Simianer H 《Tropical animal health and production》2009,41(3):403-412
Free ranging chickens reared by smallholder farmers represent genetic diversity suited for particular environments and shaped
by the socio-economic and cultural values of the farming systems. This study sought to investigate the existence of chicken
strains and evaluate the breeding goals and strategies used by village chicken farmers in Zimbabwe. A semi-structured questionnaire
was administered to 97, 56, 70, 104 and 37 households randomly selected from five agro-ecological-zones I-V, respectively.
Fifteen chicken strains mostly defined by morphological traits were reported in the five eco-zones. Production criteria such
as body size, and fertility were highly ranked (ranging from 1.3 – 2.6) by farmers across all the eco-zones, while cultural
traits were the least preferred production traits. As a common breeding practice, farmers chose the type of hens and cocks
to retain for breeding purposes and these randomly mixed and mated with others from community flocks. Chicken body size was
ranked the major determinant in choosing breeding animals followed by mothering ability, and fertility. More households culled
chickens associated with poor reproductive performance, poor growth rates and those intolerant to disease pathogens. The focus
on many negatively correlated production traits and the absence of farmer records compromises breeding strategies in these
production systems. 相似文献
10.
Groups of White Leghorn and New Hampshire male and female chicks were reared under helminth-free conditions and divided into two groups at an age of 8 weeks. One group was artificially infected with 100 embryonated Heterakis gallinarum eggs, while the other group was kept as uninfected control. After 8 weeks all animals were harvested and worm burden was established. Maximum of 60 worms per bird randomly selected were measured for length. Body weights were recorded at 8 and 16 weeks of age. Total worm burden was significantly (P<0.0001) higher in infected males than in infected females. Furthermore, White Leghorns showed a significantly (P=0.011) higher number of worms when compared with New Hampshire animals. Average worm lengths were not significantly different between the breeds (P=0.155) and sexes (P=0.062). Correlations between worm burden and worm length was 0.08 (P=0.140). The daily weight gains between 8 and 16 weeks of age of the infected animals were significantly (P=0.038) lower when compared with the control group. There was no significant correlation between daily weight gain and worm burden. The estimated heritabilities for logarithm (ln) worm burden were 0.41 (S.E.+/-0.086) in White Leghorn and 0.31 (S.E.+/-0.126) in New Hampshire, respectively. Based on the estimated heritabilities it is possible to select for H. gallinarum resistance in both genetically distinct chicken breeds. This approach may be of importance for chickens kept in floor husbandry systems. 相似文献