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61.
随着经济全球化的发展,知识产权已成为各国发展经济和参与国际竞争的关键因素之一。文章通过对我国农业领域知识产权保护现状及存在问题的分析,提出了提高农业领域知识产权保护的措施。 相似文献
62.
广州地区土地利用景观格局变化研究 总被引:32,自引:9,他引:23
以广州地区为研究区,在遥感与GIS技术的支持下,通过分析斑块和景观两个层次的格局指数变化,研究了20世纪90年代广州地区土地利用格局变化特征,结合马尔科夫过程与元胞自动机模型对广州地区2010年土地利用空间格局进行预测分析。20世纪90年代广州地区土地利用格局变化趋势是建设用地增加,耕地、林地和未利用地减少,水域和果园基本保持稳定;土地利用斑块数目增加,斑块形状指数和分维数下降;景观破碎度和多样性指数上升。21世纪头10年,研究区土地利用格局基本保持20世纪90年代的变化趋势。研究结果表明广州地区在快速城市化的过程中,土地利用格局呈破碎化趋势,斑块形状趋于简单,耕地减少没有明显减缓迹象。因此,迫切需要发挥土地利用规划的控制作用,加强耕地保护措施。 相似文献
63.
64.
Yufei Zhu Jianfei Zhao Chenxu Wang Fei Zhang Xinhuo Huang Zhouzheng Ren Xin Yang Yanli Liu Xiaojun Yang 《畜牧与生物技术杂志(英文版)》2022,(1):280-287
Background: Many researches about in ovo feeding(IOF) of vitamin C(VC) are gradually carried out to explore physiological development in chicken, but little studies focus on VC synthesis capacity of the embryo itself, the selection of injection site and the effectiveness of IOF of VC. This study aims to explore the above problems.Results: Kidney and yolk sac were the main organs for VC synthesis and L-gulonolactone oxidase(GLO) expression was lower during pre-hatch development than that during p... 相似文献
65.
Zhu Jun Luo Ancheng Zhou Yan Ndegwa Pius M. Schmidt David 《Water, air, and soil pollution》2004,151(1-4):87-101
The effect of selected nutrient amendments and temperature on the biodegradation of pentachlorophenol (PCP) within a soil biopile was studied on a laboratory scale. This was accomplished by monitoring microbial populations, the concentration of PCP and the release of inorganic chloride ions in the contaminated soil. It was found that temperatures of 10, 15 and 20 °C had no significant effect on microbial populations and the percentage of PCP remaining in the soil. However, the nutrient amendments did have a significant effect on the parameters measured. The dairy manure, ammonium nitrate fertilizer and control treatments all experienced some fluctuations in the amount of PCP remaining in the soil over the incubation period and may have been due to the release of initially unextractable bound residues. PCP decreased by 76% in the municipal solid waste compost amended soil, while the concentration of inorganic chloride ions increased. The municipal solid waste compost treatment had significantly higher bacterial and fungal populations. Based on the results of this study municipal solid waste compost may be used as an effective supplemental nutrient amendment for the degradation of PCP in soil biopiles. 相似文献
66.
基于多目标粒子群的土地整理项目选址模型 总被引:1,自引:4,他引:1
土地整理项目选址实质上是一个多目标空间优化问题,将传统选址方法用于解决多目标土地整理项目选址存在明显不足。该文提出了一种基于多目标粒子群的土地整理项目选址模型,归纳了土地整理项目选址的选址规则,提取3个能够体现土地整理项目选址目的及意义的目标函数,即新增耕地潜力最高、空间分区集中连片、土地适宜性评价指数最高,同时考虑了土地整理项目最小新增耕地率、实施规模2类约束条件,并详细阐述了算法的核心思想、矢量编码策略、状态更新机制等内容,最后选取湖北省嘉鱼县为试验区,验证了模型的可行性和有效性,结果表明通过对目标的权重调控可以得到不同目标偏好的土地整理项目选址方案,该文所构建模型在土地整理实践中具有可操作性,提供的选址方案科学合理,为土地利用规划和土地利用调控管理提供支持。 相似文献
67.
基于半方差函数与等别的耕地质量监测样点优化布设方法 总被引:3,自引:3,他引:3
耕地的数量和质量在维护国家安全、社会稳定方面具有举足轻重的作用。该文以浙江省耕地质量监测试点松阳县为例,探讨县级尺度的耕地质量监测样点的布设方法。选择自然等指数的均方差和绝对偏差计算在允许误差范围内监测样点的样本容量;采用地统计学半方差函数分析耕地质量的变异情况,利用自然等指数的变异特征与规律实现监测样点的预布设;重点分析耕地质量等别、分等因素、耕地质量潜在变化区域的空间分布,结合等别组合的空间分布特征对预布设的监测样点进行优化,得到40个监测样点。研究成果提高了监测样点的精度、代表性、科学性,方法易操作推广,具有很好的应用价值,能为耕地质量监测的管理工作提供参考。 相似文献
68.
One hundred and forty-seven Chinese barley varieties maintained at the Gene Bank of the National Barley Improvement Centre,
Zhejiang, and 84 progenies from these varieties were tested at the seedling stage for their reaction to 32 selected pathotypes
of Blumeria graminis f. sp. hordei. Eighteen resistance spectra were identified comprising single or combined resistances from eight known (Ml(Bw), Ml(Ch), Mla7, Mla8, Mla9, Mla13, MlaRu4 and Mlg) and six unknown resistance genes. The most frequent gene was Ml(Bw), which was found in 69 varieties and previously detected in only a few European winter barley varieties. The genes Mla8 and Ml(Ch) were also often present, but other resistance genes were rare. After inoculation, considerably fewer pathogen colonies were
observed in ‘Aiganqi’ and one line of ‘Tong5’. Twenty varieties were composed of lines with different resistance genes. China
is likely to be a region of origin of the genes Ml(Bw), Mla7, as well as three unknown genes found in original landraces and perhaps another three unknown genes detected in cultivars
bred in China. The resistances of varieties from the Zhejiang province and those originating from 11 other Chinese provinces
were quite different. Unfortunately, none of the varieties are promising sources of resistance to powdery mildew and China
does not seem to be a region suitable for identifying such sources. 相似文献
69.
Sarah I. Beldin Bruce A. Caldwell Phillip Sollins Elizabeth W. Sulzman Kate Lajtha Susan E. Crow 《Biology and Fertility of Soils》2007,43(6):837-841
The cation exchange capacity (CEC) of a soil depends on the type and amount of both mineral and organic surfaces. Previous
studies that have sought to determine the relative contribution of organic matter to total soil CEC have not addressed differences
in soil organic matter (SOM) composition that could lead to differences in CEC. The objectives of this study were (1) to compare
the CEC of two distinct SOM pools, the “light fraction (LF)” composed of particulate plant, animal, and microbial debris,
and the “heavy fraction (HF)” composed of mineral-bound organic matter; and (2) to examine the effects of differences in aboveground
vegetation on CEC. Soil samples were collected from four paired grassland/conifer sites within a single forested area and
density fractionated. LF CEC was higher in conifer soils than in grassland soils, but there was no evidence of an effect of
vegetation on CEC for the HF or bulk soil. LF CEC (but not HF CEC) correlated well with the C concentration in the fraction.
The mean CEC of both fractions (per kg fraction) exceeded that of the bulk soil; thus, when the LF and HF CEC were combined
mathematically by weighting values for each fraction in proportion to dry mass, the resulting value was nearly twice the measured
CEC of bulk soil. On a whole soil basis, the HF contributed on average 97% of the CEC of the whole soil, although this conclusion
must be tempered given the inflation of CEC values by the density fractionation procedure. 相似文献
70.
Long-term effect of chemical fertilizer,straw, and manure on labile organic matter fractions in a paddy soil 总被引:2,自引:0,他引:2
To assess the effect of long-term fertilization on labile organic matter fractions, we analyzed the C and N mineralization
and C and N content in soil, particulate organic matter (POM), light fraction organic matter (LFOM), and microbial biomass.
Results showed that fertilizer N decreased or did not affect the C and N amounts in soil fractions, except N mineralization
and soil total N. The C and N amounts in soil and its fractions increased with the application of fertilizer PK and rice straw.
Generally, there was no significant difference between fertilizer PK and rice straw. Furthermore, application of manure was
most effective in maintaining soil organic matter and labile organic matter fractions. Soils treated with manure alone had
the highest microbial biomass C and C and N mineralization. A significant correlation was observed between the C content and
N content in soil, POM, LFOM, microbial biomass, or the readily mineralized organic matter. The amounts of POM–N, LFOM–N,
POM–C, and LFOM–C closely correlated with soil organic C or total N content. Microbial biomass N was closely related to the
amounts of POM–N, LFOM–N, POM–C, and LFOM–C, while microbial biomass C was closely related to the amounts of POM–N, POM–C,
and soil total N. These results suggested that microbial biomass C and N closely correlated with POM rather than SOM. Carbon
mineralization was closely related to the amounts of POM–N, POM–C, microbial biomass C, and soil organic C, but no significant
correlation was detected between N mineralization with C or N amounts in soil and its fractions. 相似文献