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41.
In our previous research, the possibility of using chitosan in preparing the pretreatment print paste for digital ink-jet
printing for cotton fabric was investigated but the final color was not good as expected. In this paper, we modified our previous
work by applying the chitsoan separately on the cotton fabric for digital ink-jet printing. A two-bath method was thus proposed
and it was confirmed that a better color yield was achieved with this method. However, the use of chitosan reduced the tensile
strength of the digital ink-jet printed fabric slightly. 相似文献
42.
提出了一种基于视觉的泡罩包装缺陷检测方法.首先将表面图像分成泡罩区和底板区两部:令.在泡罩区先采用基于HIS颜色空间的合成颜色特征矢量提取出药片边缘,计算药片属性,然后采用改进的闵可夫斯基距离法进行药片颜色匹配.底板区通过提取基于共生矩阵的纹理特征,采用反向传播神经网络分类器进行缺陷识别,实验证明:泡罩区采用的算法不仅药片边缘定位精度高,而且可有效检测药片的污物、色斑等缺陷;底板区采用的识别算法能够检测各种纹理的复杂缺陷. 相似文献
43.
国土空间生态修复与乡村振兴:共现与融合 总被引:1,自引:1,他引:0
为把握乡村振兴背景下国土空间生态修复领域研究的重点方向,并对我国乡村振兴生态修复规划、实践以及未来相关研究提供参考,采用文献计量学的方法,对中国知网2004—2021年以乡村振兴背景下国土空间生态修复为检索主题得到的830篇期刊文献绘制知识图谱,并基于文献计量结构总结了中国国土空间生态修复与乡村振兴的图谱共现关系。通过系统梳理乡村三生空间-国土空间生态修复-国土空间综合整治的衔接融合关系,明确未来应着力强调人地系统耦合的国土空间生态修复新阶段,提出基于乡村三生空间视角,从生产-生态、生活-生态、人类福祉-生态等方面探索乡村国土空间生态修复的实施路径与技术集成模式。基于国土空间生态修复新思维完善乡村三生空间动态的系统观,在提升人类生态福祉的基础上,推动生态修复向高级阶段发展,持续推进落实生态文明建设与乡村振兴重大战略。 相似文献
44.
Yuying MA Pamela WEISENHORN Xisheng GUO Daozhong WANG Teng YANG Yu SHI Huanchao ZHANG Haiyan CHU 《土壤圈》2021,31(4):538-548
Fertilization has been shown to exert a significant influence on soil microorganisms and directly and indirectly influences plant growth and survival in agroecosystems. However, it is unknown whether fertilization affects endophytic microbial communities, which are ubiquitous and intimately associated with plant growth and health. Herein, we investigated endophytic bacterial communities in wheat leaves and roots under different long-term fertilization regimes, including NPK chemical fertilizer and NPK chemical fertilizer combined with wheat straw, pig manure, or cow manure. Endophytic bacterial community composition considerably differed in leaves and roots. Although different fertilization treatments did not affect the endophytic bacterial species richness or phylogenetic diversity in either leaves or roots, the community composition was significantly altered, particularly in roots. The endophytic bacterial co-occurrence network in leaves was more complex and stable than that in roots. Furthermore, many of the keystone species that were identified by their topological positions in the co-occurrence networks of leaves and roots were involved in plant growth and fitness. The total relative abundance of keystone species was the highest in the NPK plus cow manure treatment in both leaves and roots. Overall, our results suggest that different fertilization regimes can strongly affect endophytic bacterial communities, and the combination of NPK fertilizer and cow manure promoted the relative abundance of the key endophytic bacterial microbiota in both leaves and roots, which might be beneficial for plants in agroecosystems. 相似文献
45.
In terms of production, seabream and seabass are the two most important species of marine Mediterranean aquaculture, which is why they have been extensively studied in the literature. This study uses visualization analysis with the CiteSpace software to determine the research status quo and the most important trends of seabream and seabass aquaculture research. The Web of Science (WoS) database was used to select the papers associated with seabream and seabass literature from the period between 1986 and 2020. The results were separated using two indices (Science Citation Index Expand and Social Science Citation Index). The visualization analysis identified the networks for (1) author, institution, country and category co-authorship, in order to find the most prolific authors, institutions, countries and categories respectively; and (2) journal, document and author co-citation, which identifies the most relevant journals, the most important studies and the most cited and influential authors. Finally, a keywords co-occurrence network was built to identify the most important topics and the research frontiers—body of knowledge—of the seabream and seabass aquaculture research—SSAR. 相似文献
46.
【目的】研究甘蓝尾菜与干水稻(Oryza sativa L.)秸秆混贮发酵过程中理化指标、微生物群落变化,并分析二者之间的相关性,旨在为甘蓝尾菜和干水稻秸秆饲料化利用提供参考。【方法】将甘蓝(Brassica oleracea L.)尾菜与干水稻秸秆在30 ℃条件下混合贮存30 d,分别在发酵的第0,3,7,15,30天取样,分析样品的发酵品质、营养成分,利用Illumina Miseq高通量测序研究发酵过程中微生物菌群结构,使用Mothur 1.30.2分析细菌和真菌的Alpha多样性指数(Coverage指数、Shannon指数、Chao1指数),结合BugBase和FUNGuild数据库分析细菌和真菌群落的表型功能,再利用共现性网络、冗余分析(RDA)分别研究菌群互作以及理化指标与优势物种相关性。【结果】与发酵前相比,甘蓝尾菜与干水稻秸秆混贮发酵结束后pH、干物质(DM)含量、水溶性碳水化合物(WSC)含量显著下降(P<0.05),有机酸(乳酸、乙酸、丁酸)和乙醇显著积累(P<0.05),其中铵态氮含量在贮存结束时低于10%,pH降低到4.0;粗脂肪(CF)、粗蛋白(CP)、酸性洗涤纤维素(ADF)含量无显著变化(P>0.05),中性洗涤纤维素(NDF)含量显著上升(P<0.05)。细菌和真菌群落的Coverage指数为0.99~1.00;细菌群落的Shannon指数、Chao1指数于发酵第3 天之后均显著下降(P<0.05),真菌群落的Shannon指数和Chao1指数无显著变化(P>0.05)。发酵过程中,优势细菌(相对丰度(RA)>5%)由初始的非理想菌群转变为乳酸菌和肠杆菌类,真菌群落中致病型菌群相对丰度显著下降(P<0.05)。9种细菌表型和12种真菌表型被注释,其中需氧型(aerobic)、形成生物膜(forms biofilms)、革兰氏阴性(gram negative)、潜在致病型(potentially pathogenic)细菌和动物致病型(animal pathogenic)真菌相对丰度均显著下降(P<0.05),在30 d时相对丰度分别为8.0%,31.5%,31.8%,31.3%,15.46%。基于物种属水平相对丰度构建的微生物共现性网络由38个点(代表细菌属或真菌属)和91条无向的边(代表相连细菌属或真菌属之间的相关性)组成。与发酵前相比,乳酸菌(片球菌属Pediococcus、肠球菌属Enterococcus、乳杆菌属Lactobacillus、未分类的乳杆菌科unclassified_f__Lactobacillacea)和腐生型真菌(节担菌属Wallemia和unclassified_f__Dipodascaceae)作为关键物种抑制了病原菌富集;片球菌属Pediococcus、unclassified_f__Dipodascaceae是甘蓝尾菜和干水稻秸秆混贮发酵过程中改善青贮品质的关键物种。RDA结果显示,pH、WSC、CF是影响微生物优势物种演替的关键理化因子,其中pH、WSC与优势物种镰孢菌属、曲霉属、泛菌属、肠杆菌属呈正相关关系,与片球菌属、未分类的肠杆菌科呈负相关关系;CF与优势物种肠球菌属、节担菌属呈负相关关系。【结论】甘蓝尾菜与干水稻秸秆混贮发酵过程中,干物质含量被有效保存,真菌优势物种显著富集,有效抑制了病原菌菌群的积累,可知混贮发酵是资源化处理甘蓝尾菜与干水稻秸秆的有效方式。 相似文献
47.
Wenhao JIN Jiangfei GE Shuai SHAO Liyuan PENG Jiajia XING Chenfei LIANG Junhui CHEN Qiufang XU Hua QIN 《土壤圈》2024,34(2):508-519
Intensive management is known to markedly alter soil carbon (C) storage and turnover in Moso bamboo forests compared with extensive management. However, the effects of intensive management on soil respiration (RS) components remain unclear. This study aimed to evaluate the changes in different RS components (root, mycorrhizal, and free-living microorganism respiration) in Moso bamboo forests under extensive and intensive management practices. A 1-year in-situ microcosm experiment was conducted to quantify the RS components in Moso bamboo forests under the two management practices using mesh screens of varying sizes. The results showed that the total RS and its components exhibited similar seasonal variability between the two management practices. Compared with extensive management, intensive management significantly increased cumulative respiration from mycorrhizal fungi by 36.73%, while decreased cumulative respiration from free-living soil microorganisms by 8.97%. Moreover, the abundance of arbuscular mycorrhizal fungi (AMF) increased by 43.38%, but bacterial and fungal abundances decreased by 21.65% and 33.30%, respectively, under intensive management. Both management practices significantly changed the bacterial community composition, which could be mainly explained by soil pH and available potassium. Mycorrhizal fungi and intensive management affected the interrelationships between bacterial members. Structural equation modeling indicated that intensive management changed the cumulative RS by elevating AMF abundance and lowering bacterial abundance. We concluded that intensive management reduced the microbial respiration-derived C loss, but increased mycorrhizal respiration-derived C loss. 相似文献
48.
49.
基于高阶谱法作物重金属污染元素判别与污染程度诊断 总被引:1,自引:0,他引:1
基于不同铜离子(Cu~(2+))和铅离子(Pb~(2+))胁迫梯度下玉米叶片光谱微分数据,结合高阶谱估计与灰度-梯度共生矩阵(Gray gradient co-occurrence matrix,GGCM)的特征提取方法,提出了Cu~(2+)和Pb~(2+)污染定性分析、污染元素种类识别和污染程度诊断的方法。首先,测量了不同胁迫梯度下玉米叶片光谱数据以及叶片中富集的Cu~(2+)、Pb~(2+)含量;然后,利用高阶谱估计的ARMA模型参数法对各类玉米叶片微分光谱数据序列进行双谱估计,得到bisp_rts和bisp_qs矩阵及其相应的双谱三维图,从而可以直观可视地定性分析玉米是否已受Cu~(2+)和Pb~(2+)污染,辨别出Cu~(2+)或Pb~(2+)污染的元素类别;最后,构造bisp_rts和bisp_qs矩阵相应的GGCM,通过提取各GGCM的纹理参量特征值,诊断玉米叶片受Cu~(2+)和Pb~(2+)的污染程度。实验结果表明:高阶谱估计可以定性分析玉米老叶(O)、中叶(M)、新叶(N)是否已受Cu~(2+)和Pb~(2+)污染,也可辨别出O、M叶片所受Cu~(2+)或Pb~(2+)污染的元素类别;bisp_rts矩阵的灰度分布不均匀性(T1)、能量(T2)特征值均能反映O、M叶片中Pb~(2+)含量的变化,能较好地诊断O、M叶片中Pb~(2+)的污染程度,而bisp_qs矩阵的小梯度优势(T3)特征值能反映O、M叶片中Cu~(2+)含量的变化,能较好地诊断O、M叶片中Cu~(2+)的污染程度。 相似文献
50.
基于IKONOS高分辩率影像的城市草地信息提取研究 总被引:2,自引:0,他引:2
在IKONOS影像图上提取草地信息试用了2种方法进行探索,分别采用植被指数法和基于灰度共生矩阵的纹理量分类法.前者用MSAVI指数分类提取得到的精度为87.48%;后一种方法是通过从近红外波段提取灰度共生矩阵和灰度联合矩阵,计算并提取理想窗口的最能反映类别差异的纹理量值,试验发现取3X3窗口的CON纹理量可以较好地提取出草地信息,通过精度评估发现具有较高的精度(平均精度达90.56%).研究证明用该法提取草地信息可取得相对理想的精度效果. 相似文献