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杉木林历来采用下层抚育间伐作业。杉木林上层,下层抚育间伐对比试验说明,上层抚育间伐能比下层抚育间伐显著地提高林分生长量。本文论述了上层抚育间伐显著提高林分生长量的机理,并提出上层抚育可应用于杉木林的首次间伐。 相似文献
184.
指出了交通运输沟通生产和消费,是社会经济发展的先决动力。从六安市铁路交通和经济发展现状的视角,利用六安市近年来的统计数据,对六安交通运输对其经济发展的影响进行了研究。结果表明:交通运输虽然为六安市区域经济发展提供了条件,但六安市经济发展目前仍依赖传统发展模式,农业比重偏高,区域产业结构仍需进一步优化。因此,结合交通运输条件的联接性,从产业发展、产业布局和城镇发展三个方面对六安市区域经济的发展提出了具体策略。 相似文献
185.
W. Zhang N. S. Zhang J. J. Zhao Z. Y. Zhao L. X. Mei 《The Journal of Horticultural Science and Biotechnology》2017,92(5):539-549
Potassium (K) fertilization and antioxidant enzymes both positively influence plant growth and development. However, it is not known whether K treatment improves fruit development via increasing soluble sugar. In this study, K-treated apple (Malus domestica Borkh.) fruit was harvested from 60 to 150 days after full bloom and was analyzed for ROS production and trehalose metabolism. The results show that K fertilization improved fruit firmness, increased growth according to several parameters, increased soluble sugar content, and decreased ROS production. The ascorbate metabolic pathway more effectively reduced ROS production than catalase and peroxidase (POD) did under K treatment. Trehalose-treated fruit also showed higher activity of ascorbate-related enzymes (DHAR, GR, and APX) compared with non-treated fruit. The changes of antioxidant enzyme activity in trehalose-treated fruit corresponded to those in K-treated fruit. Moreover, trehalase (TREH) activity in fruit was notably reduced by K treatment. This demonstrates that K influences ROS production via regulating trehalose content and TREH activity in fruit. This study provides new insight into the K mechanism which improves fruit development, including fruit firmness and size. 相似文献
186.
Chen Zhaoming Wang Qiang Zhao Jun Chen Yudong Wang Huoyan Ma Junwei Zou Ping Bao Li 《Journal of Soils and Sediments》2020,20(3):1502-1512
Journal of Soils and Sediments - Nitrogen (N) fertilizer placement in bands is a widely accepted agricultural practice to increase N use efficiency. An excessive ammonium concentration in a... 相似文献
187.
The design and development of innovative multifunctional wound dressing materials in engineered biomaterials is essential for promoting tissue repair. In this study, nanofibrous wound dressing materials loaded with anti-inflammatory ingredients were manufactured by a promising electrospinning strategy, and their capability for treating diabetic wounds was also investigated. A scaffold blend consisting of an Enteromorpha polysaccharide and polyvinyl alcohol (PVA) was fabricated. The in vitro and in vivo studies confirmed the efficacy of PVA/EPP1 fiber. We found that PVA/EPP1 fiber accelerated the repair of a full-thickness skin wound in diabetic mice. The results suggest that this scaffold could effectively shorten the wound healing time by inhibiting inflammatory activity, which makes it a promising candidate for the treatment of hard-to-heal wounds caused by diabetes. 相似文献
188.
文章就卵母细胞体外成熟的影响因素做了简要的论述。主要介绍了卵母细胞来源、培养系统、激素和生长因子等因素对卵母细胞体外成熟的影响。 相似文献
189.
QI Peng-fei WEI Yu-ming Ouellet Therese CHEN Qing WANG Zhao WEI Zhen-zhen ZHENG You-liang 《农业科学学报》2014,13(2):290-298
γ-Gliadins are an important component of wheat seed storage proteins. Four novel γ-gliadin genes (Gli-ngl to Gli-ng4) were cloned from wheat (Triticum aestivum) and Aegilops species. The novel γ-gliadins were much smaller in molecular size when compared to the typical γ-gliadins, which was caused by deletion of the non-repetitive domain, glutamine-rich region, 3" part of the repetitive domain, and 5' part of the C-terminal, possibly due to illegitimate recombination between the repetitive domain and the C-terminal. As a result, Gli-ngl and Gli-ng4 only contained two and three cysteine residues, respectively. Gli-ngl, as the representative of novel γ-gliadin genes, has been sub-cloned into an Escherichia coli expression system. SDS- PAGE indicated that the both cysteine residues of Gli-ngl could participate in the formation of intermolecular disulphide bonds in vitro. Successful cloning of Gli-ngl from seed cDNA of T. aestivum cv. Chinese Spring suggested that these novel γ-gliadin genes were normally transcribed during the development of seeds. Phylogenic analysis indicated that the four novel γ-gliadin genes had a closer relationship with those from the B (S) genome of wheat. 相似文献
190.