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221.
采用CCN6000水稻叶片氮素快速测定仪,以籼型常规早稻中早39为材料,研究了水稻叶片氮含量化学分析值、CCN值及SPAD值的关系。结果表明,早稻倒1叶叶片CCN值与含氮量呈近1.0∶1.0的关系,倒2叶叶片CCN值与含氮量呈近1.0∶1.1的关系,倒3叶叶片CCN值与含氮量呈近1.0∶1.2的关系,倒1叶CCN值与含氮量之间最为吻合,CCN值与SPAD值显著相关。水稻孕穗期叶片含氮量为倒3叶倒2叶倒1叶。研究表明,CCN值可以作为叶片含氮量的快速诊断依据。 相似文献
222.
223.
[目的]采取淋洗、冲洗或两者并用措施,对恰布拉村牧民定居点盐碱土壤进行改良,为改良盐碱化土壤,提高现有土地生产能力提供科学依据.[方法]分别在排碱渠临界条田20、40、60和80 m处采取0~80cm土样(20 cm为1层)测定其土壤电导率变化(试验1).对盐碱化土壤进行冲洗(A区)、淋洗(B区)或两者并用(AB区)处理和对照区(CK区),测定0~80 cm处(10 cm为1层)土壤电导率、阳离子含量变化,与对照区进行比较分析(试验2).[结果]排碱渠的排盐碱有效距离为0~40 m;B区的电导率ECe值每一层基本都在11~12 ms/cm,与A区相比表层土ECe值明显降低;50 cm以下的土壤ECe值变化幅度各处理间差异不大.0~50 cm土壤的pH值变化无规则,但下层土壤pH值均呈下降趋势,其顺序为B、AB、A、CK.A区表层土Na+含量降低,但下层土壤中含量比A、AB和CK区高,表明盐碱溶解后被冲至下层.[结论]淋洗对盐碱土壤改良的效果最佳,降低了土壤电导率和Na+含量. 相似文献
224.
Abstract: Age, growth and sexual maturity of the fan ray Platyrhina sinensis in Ariake Bay, Japan were determined from specimens collected from May 2002 to September 2006. Age determination was conducted by vertebral centrum analysis using soft X-radiography. Annual band pair deposition was determined by marginal increment and edge analyses. The von Bertalanffy growth model best described the overall pattern of growth for both males and females (males L ∝ = 455.2, k = 0.56, t 0 = −1.09; females L ∝ = 555.8, k = 0.28, t 0 = −1.77; L ∝ is the theoretical asymptotic total length in mm, k is the growth rate coefficient and t 0 is the theoretical time at zero length). Parameter estimates suggest that females attain a larger asymptotic total length and grow more slowly than males. The observed maximum ages were 5 years for males and 12 years for females. Age at 50% sexual maturity was 2.1 years for males and 2.9 years for females. The results indicate that this species is relatively fast-growing, short-lived and early maturing compared with many batoid species. 相似文献
225.
Keisuke Obase Joo Young Cha Jong Kyu Lee Sang Yong Lee Kun Woo Chun 《Journal of Forest Research》2012,17(4):388-392
We investigated the ectomycorrhizal (EcM) fungal community of naturally regenerating Pinus densiflora seedlings on exposed decomposed granite (DG) slopes along woodland paths in the Republic of Korea. We sampled three- to five-year-old seedlings from slopes where DG was exposed (habitat S) and from the surrounding forest edge or gaps (habitat F). We classified EcMs into morphological groups and counted the number of root tips. The fungal taxa were determined by sequencing the internal transcribed spacer region of their nuclear rDNA. We observed a total of 27 EcM fungal taxa. Atheliaceae and Rhizopogon were the dominant taxa on exposed DG slopes. The fungal species compositions were similar between habitats (0.59 as calculated by the Morishita–Horn index). Fourteen fungal taxa were common to both habitats, and these accounted for more than 90% of the relative abundance in each habitat. There were no significant differences in relative abundance and colonization frequency of each EcM fungal taxon between the habitats, except for Russula sp. 2, which was significantly more frequent in habitat F than in habitat S. Our results indicated that P. densiflora seedlings on exposed DG slopes associated with EcM fungi that were common in forests and not specific to the exposed DG slopes. 相似文献
226.
The representative carbon footprint of product (CFP) value of “certified wood in Kyoto Prefecture” was calculated as 241?kg-CO2/m3. The CFP value was 158?kg-CO2/m3 when wood was not kiln dried and final processing was not involved, whereas that of “kiln-dried, finished wood” was 284?kg-CO2/m3. Comparisons of different types of wood were also conducted to examine CO2 emission-reducing effects of “certified wood in Kyoto Prefecture”. We compared the CFP of lumber produced (in Japan) from logs supplied from Japan and other countries and that of “certified wood in Kyoto Prefecture”; the lumber products as a target for comparison are shipped to markets throughout the country. The CFP of “certified wood in Kyoto Prefecture” was approximately 50% lower compared to that of North American wood lumbered in Japan and shipped to markets throughout the country, and about 30% lower compared to the mean CFP of lumber produced (in Japan) from logs supplied from Japan and other countries and shipped to markets throughout the country. We then compared the CFP of “products imported from other countries after being cut into lumber” to that of “certified wood in Kyoto Prefecture”. The CFPs of lumber products from North America and Europe were lower than that of “certified wood in Kyoto Prefecture” (kiln-dried, finished wood). However, when only woodchips were used as a heat source in the process of kiln drying, the CFP of “certified wood in Kyoto Prefecture” was lower than any other kiln-dried lumber products. Regarding “certified wood in Kyoto Prefecture”, the use of woodchips as a heat source in the process of kiln drying or a shift to air drying decreases the CFP. 相似文献
227.
Fuxiang Chang Seung-Hwan Lee Keisuke Toba Asahiro Nagatani Takashi Endo 《Wood Science and Technology》2012,46(1-3):393-403
A new approach to prepare cellulose nanofiber was attempted using the combined method of hot-compressed water (HCW) treatment and disk milling. The HCW treatment was effective in loosening the cell wall structure and enhancing fibrillation by disk milling. The fibrillated products showed fine fibrous morphology at the nanometer scale. Filtration time and specific surface area were measured as criteria of the degree of fibrillation, and both these values were increased in nanofibers obtained by disk milling after HCW treatment. The obtained nanofiber-reinforced polyurethane composite was prepared, and its tensile properties were drastically improved by the increased nanofiber content. 相似文献
228.
Md Nazrul Islam Khandkar-Siddikur Rahman Md Mezbaul Bahar Md Ahsan Habib Keisuke Ando Nobuaki Hattori 《Urban Forestry & Urban Greening》2012,11(4):460-464
Greenbelts are effective tools for mitigation of traffic induced air and noise pollution. In this study, the potential role of greenbelts along the roadside for the reduction of air pollution and noise levels has been assessed by using seasonally monitored data in a megacity of Bangladesh. Correlation analysis was performed between the vegetation status, measured by canopy density and shelterbelt porosity, and the total suspended particles (TSP) removal percentage. Further, the reduction of noise level was also analyzed. The results showed that the greenbelts greatly contributed to reduce TSP pollution and it was as much as 65%. Noise level reduction was also achieved up to 17 dB when compared to the open area. Moreover, TSP removal percentage was correlated to the crown density. Area having higher crown density demonstrated less air pollution and lower level of noise compared to the area having lower crown density. Greenbelt showed better performance in summer time than winter. 相似文献
229.
Water, Air, & Soil Pollution - The relation among the mean slope angle of a watershed, the stream water quality, and the chemical composition of the plagioclase component of granite was... 相似文献
230.
Zhu XL Matsui T Watanabe K Shiraishi K Ueki T Matsumoto K 《Journal of agricultural and food chemistry》2007,55(21):8367-8371
A replicate heart-cut column-switching HPLC method combined with two switching valves was newly developed for the simultaneous determination of three antihypertensive peptides (Ala-Phe, Tyr-Pro, and Trp-Tyr) in tryptic casein hydrolysate in one run-in assay. After a first separation on an octadecyl silane (ODS) column, heart-cuts of each peptide were individually separated on a subsequent analytical ODS column: 26% acetonitrile for Ala-Phe and Tyr-Pro (32% for Trp-Tyr) in 0.1% trifluoroacetic acid containing 10 mM sodium 1-octanesulfonate at 0.8 mL/min. Ala-Phe, Tyr-Pro, and Trp-Tyr in casein hydrolysate were determined within 70 min to be 0.377 +/- 0.037 mg/g, 2.50 +/- 0.26 mg/g, and 0.096 +/- 0.008 mg/g, respectively. 相似文献