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901.
通过对一维Theta-神经元网络中细胞耦合作用时间的讨论,得到较长时间的耦合作用时间会使网络中单放电行波变为多放电行波,并通过数值模拟对理论加以验证. 相似文献
902.
《Communications in Soil Science and Plant Analysis》2012,43(3):187-195
Abstract A field experiment was conducted to determine whether Zn applied for pathogen control could accumulate to a level which would be toxic to snapbeans, cucumbers, or corn. Zinc sulfate (ZnSO4) was applied at rates varying from 0 to 363 kg Zn/ha on a Flainfield loamy sand to approximate 3, 9, 27 and 81 years of fungicidal treatment. Even at the high rate of Zn, yields of snapbeans, cucumbers, or corn generally were not reduced. As rates of applied Zn increased, there was a corresponding increase in the level of Zn in the leaf tissue of all crops grown. At the high Zn rate, snapbean and cucumber leaf tissue accumulated over 350 ppm Zn. Available soil Zn was extracted with 0.1N HCl, EDTA, or DTPA. Highly significant correlations were observed between the Zn removed by each extractant and plant tissue Zn, thus, indicating that the various extractants were equally effective in predicting Zn uptake. Very little downward movement of Zn was observed. Two and one‐half years after application, the Zn had leached to a depth of only 30 cm in the soil profile at the higher Zn rates. These data indicate that application of Zn‐containing fungicides and bactericides should not cause a Zn toxicity problem on the Plainfield sand in the foreseeable future. 相似文献
903.
904.
《Scandinavian Journal of Forest Research》2012,27(1-4):386-396
The location of Capercaillie lekking sites was compared in forest mosaics of different level of fragmentation. In north Finland the stand characteristics of the lekking sites did not differ from those of randomly selected stands in the 1950s judged from forestry maps and stand registers. In the 1980s, when forestry had considerably altered stand structure, lekking stands were older, larger and had a higher timber volume than random stands. These features evenly changed from the lek centre to the distance of 4 km, to which distance the adjacent areas were assessed. Southern and central Finnish analyses, based on topographic maps, showed that the proportion of forest distinctly decreased with increasing distance from a lek centre, up to a distance of 1–1.5 km. The average patch size of lekking stands were largest in the north (where both cut areas and remaining stands are large) and smallest in central Finland dominated by fine‐grained forest landscape. The results are discussed in terms of landscape ecology and forestry planning. 相似文献
905.
Zhi-Juan Ji Xiao-Guang Wang Yu-Xiang Zeng Liang-Yong Ma Xi-Ming Li Bing-Xin Liu Chang-Deng Yang 《Breeding Science》2012,62(1):71-77
Five physiological and eleven yield traits of two pairs of sister lines generated from a high generation with similar genetic background (SLs) for purple pericarp were investigated to explore the reasons behind low-yield production of colored rice. Of the five physiological traits examined, except grain anthocyanin content, there were generally similar trends between the P (purple-pericarp) lines and the corresponding W (white-pericarp) lines over two seasons (in the year 2009 and 2010 separately). The results demonstrated that the chlorophyll content of flag leaves, the net photosynthetic rate of flag leaves, and the grain anthocyanin content could be easily influenced by the environment. The physiological functions of the traits for the P lines were more active than those of the corresponding W lines in the year 2010. The grain anthocyanin content of the P lines was much greater in the year 2010 than in the year 2009 during the growth period. The investigation of yield traits revealed that the P lines had reduced 1000-grain weight, yield per plot and grain/brown rice thickness compared to the W lines. A difference comparison of these traits and a source-sink and transportation relationship analysis for these SLs suggested that small sink size was a key reason behind yield reduction of purple pericarp rice. 相似文献
906.
907.
爱能5 号母本系湘蜜西瓜F1 自交12 代得到的稳定单系XM12,父本系西农8 号F1 自交10代得到的稳定单系XL10。植株生长势强,分枝力强,易坐果。果实椭圆形,果皮黑色,单瓜质量4 ~7kg,果皮厚1.1 cm 左右,瓤红色,肉质细脆,汁多味甜,中心可溶性固形物含量10% 左右。全生育期93d(天)左右,中熟,雌花开放~果实成熟约需32 d(天)。高抗枯萎病,抗疫病和炭疽病,适宜在湖南省及其周边地区种植。 相似文献
908.
不同氮磷配比对旱作土壤养分和油葵产量的影响 总被引:1,自引:0,他引:1
采用调查分析、田间试验等方法,研究了旱作土壤条件下油用向日葵氮磷肥的吸肥特性和对氮磷肥的吸收规律。结果表明:不同厚度(0~20cm)和(20~40cm)的土壤对养分的吸收呈现动态的变化特点,施氮270.0kg/hm2时吸收氮素分别为47.5和35.7mg/kg,相差24.8%;油葵产量为2 604.0kg/hm2,施磷100.05kg/hm2时吸收磷素分别为28.4和21.5mg/kg,相差24.2%,油葵产量为3 199.5kg/hm2。 相似文献
909.
Screening and Analysis of Proteins Interacting with TaPDK from Physiological Male Sterility Induced by CHA in Wheat 总被引:1,自引:0,他引:1
To further research the regulatory network of pyruvate dehydrogenase kinase (designated as TaPDK) in physiological male-sterility (PHYMS) of wheat induced by chemical hybridizing agent (CHA) SQ-1, an anther cDNA library was constructed, and the proteins interacting with TaPDK were screened via yeast two-hybrid technique. Subsequently, a few candidate proteins in nucleotide expression levels were detected by real-time quantitative PCR. Yeast-two hybrid screening was performed by mating yeast strain Y2HGold containing BD-TaPDK bait plasmid with yeast strain Y187 including anther cDNA library plasmid. Diploid yeast cells were plated on synthetic dropout nutrient medium (SD/-Ade/-His/-Leu/-Trp) (QDO), and further were incubated on QDO medium containing AbA and X-α-Gal. The interactions between TaPDK and the proteins obtained from positive colonies were further confirmed by co-transformation validation. After plasmids DNA were extracted from blue colonies and sequenced, the sequences results were analyzed by bioinformatic methods. Finally, 24 colonies were obtained, including eight genes, namely non-specific lipid-transfer protein precursor (TanLTP), polyubiquitin (TaPUbi), glyceraldehyde-3-phosphate dehydrogenase, proliferating cell nuclear antigen (TaPCNA), CBS domain containing protein (TaCBS), actin, guanine nucleotide-binding protein beta subunit, chalcone synthase, and three new genes with unknown function. The results of quantitative RT-PCR showed that the expression levels of TanLTP, TaPUbi, and TaPCNA were obviously up-regulated in PHYMS anther, and TaCBS expression was only increased at the tricellular stage in PHYMS anther compared with in fertile lines. Whereas, the expression of TaPDK was obviously down-regulated in PHYMS lines. Collectively, these datas indicated that the majority of candidate proteins might be related to pollen abortion in PHYMS lines, which further suggested that TaPDK plays multiple roles in pollen development, besides participating in regulating pyruvate dehydrogenase complex activity. 相似文献
910.
水稻霜霉病诊断特征为植株矮缩,叶片黄化、产生黄褐色条斑.利用显微镜检查染色病组织内的病原菌藏卵器和卵孢子,通过观察病原菌的培养性状、形态特征和致病性测定,该病原菌被鉴定为大孢指疫霉水稻变种. 相似文献