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61.
城市群是中国区域经济与绿色发展的主要承载形式,其战略地位与日俱增,在实现碳中和、碳达峰目标下研究城市群减污降碳协同治理,是探索区域可持续发展的重要内容。基于减污降碳协同治理演化机理,借助2010—2019年三大城市群的面板数据,采用相关系数矩阵法、复合系统协同度模型测度城市群减污降碳协同治理协同度;结合基尼系数、变异系数、泰尔指数、引力模型等方法分析城市群减污降碳协同治理区域差异及空间联系强度;并对减污降碳协同治理关键路径进行识别。结果表明：①三大城市群减污降碳协同治理有序度呈显著增长趋势;而减污降碳协同治理协同度水平较低,系统处于不稳定、不协调的状态。②京津冀减污降碳协同治理度内部差异逐步减小,长三角内部差异基本保持稳定,珠三角内部差异波动较大。③京津冀和珠三角减污降碳协同治理协同度的网络密度和网络结构的复杂程度高于长三角,空间联系强度等级较高。为此,三大城市群减污降碳协同治理可以从政策、技术、能力建设等方面,通过做好顶层设计、转型升级、合作拓展等路径予以推进。 相似文献
62.
阿维菌素生物合成及其代谢途径研究进展 总被引：1，自引：0，他引：1
阿维菌素(avermectin)是由阿维链霉菌(Streptomyces avermitilis)产生的一种具有杀虫活性的大环内酯类抗生素,在农业和畜牧业中应用广泛。本文综述了有关阿维菌素生物合成以及阿维菌素育种和代谢工程方面的最新研究进展。 相似文献
63.
赤霉素是一类植物内源激素,影响植物的生长和发育．“绿色革命”使一年生作物的产量大幅度提高,人们因此认识到赤霉素在生产中的巨大作用,也使赤霉素的研究得到进一步的加强．随着分子生物学的发展,赤霉素生物合成途径中的基因在拟南芥、烟草、水稻等植物中被逐渐克隆出来．文章介绍了赤霉素的生物合成途径在拟南芥、南瓜等作物中的研究情况以及一些矮化突变体,着重概述了苹果中赤霉素生物合成途径的研究进展,为苹果矮化的分子育种提供理论支持． 相似文献
64.
探讨TLR-NF-кB信号通路及NF-кB不同程度表达在变应性鼻炎(Allergic Rhinitis,AR)发病中的作用及雷公藤多甙(tripterygium wilfor-dii hook,TWH)的干预。应用卵清蛋白建造AR细胞模型,ELISA法测IgE含量,Real-Time PCR及Westernblot检测TLR及NF-кB的表达。结果,模型组IgE、TLR-4及NF-кB的表达较正常组均高;LPS组TLR-4及NF-кB的表达进一步增强,IgE的表达较模型组反而降低;DEX组及TWH组TLR-4及NF-кB、IgE的表达较模型组均降低(P<0.05);TLR4与NF-кB的表达高度相关。结果表明,TLR-NF-кB信号传导通路在AR发病中发挥作用,NF-кB的过高表达抑制IgE的生成,产生免疫偏移作用。 相似文献
65.
Teresa Zwierko Wojciech Lubiński Piotr Lesiakowski Hanna Steciuk Leszek Piasecki Justyna Krzepota 《Journal of sports sciences》2013,31(16):1519-1528
AbstractThis longitudinal study investigated visual evoked potentials (VEPs) in 11 young female volleyball players who participated in extensive training for 2 years. The control group consisted of 7 age-matched female students who were not involved in any regular sports activity. Recordings of VEPs were performed twice: baseline recording (i.e., before training began) and after 2 years of systematic, volleyball-specific athletic training. The effect of athletic training on visual signal conductivity was assessed by recording the latency of N75, P100 and N135 components of the VEPs waveform. Extensive experience with volleyball training reduced signal conductivity time through visual pathway. Specifically, the latency of P100 was reduced on average by 2.2 ms during binocular viewing. Moreover, athletes had reduced N75 latency (difference of 3.3 ms) for visual stimuli that generated greater response from peripheral retina. These results indicate that sport training can affect very early sensory processing in athletes. 相似文献
66.
加强对高职学生可持续发展能力的培养,是社会发展和学生成长成才的需要。高职学生可持续发展能力由多种要素构成,高职院校应通过多种途径对学生进行培养。 相似文献
67.
Zhang-fei Shou Qin Zhou Jie-ru Cai Jiang-hua Chen Kazuya Yamada Kaoru Miyamoto 《Journal of Zhejiang University. Science. B》2009,10(9):702-706
1-3 kinase pathway can mediate this effect. 相似文献
68.
Cheryl J. Craig Rakesh Verma Donna Stokes Paige Evans Bobby Abrol 《International Journal of Science Education》2018,40(6):621-643
This research examines the influence of parents on students’ studying the STEM disciplines and entering STEM careers. Cases of two graduate students (one female, one male) and one undergraduate student (male) are featured. The first two students in the convenience sample are biology and physics majors in a STEM teacher education programme; the third is enrolled in computer science. The narrative inquiry research method is used to elucidate the students’ academic trajectories. Incidents of circumstantial and planned parent curriculum making surfaced when the data was serially interpreted. Other themes included: (1) relationships between (student) learners and (teacher) parents, (2) invitations to inquiry, (3) modes of inquiry, (4) the improbability of certainty, and (5) changed narratives?=?changed lives. While policy briefs provide sweeping statements about parents’ positive effects on their children, narrative inquiries such as this one illuminate parents’ inquiry moves within home environments. These actions became retrospectively revealed in their adult children’s lived narratives. Nurtured by their mothers and/or fathers, students enter STEM disciplines and STEM-related careers through multiple pathways in addition to the anticipated pipeline. 相似文献
69.
The study focuses on the ways in which people define their source preferences in the context of seeking problem-specific information for non-work purposes. The conceptual framework draws on two major concepts, that is, information source horizon and information pathways. The former denotes the ways information sources are mapped in preference order in an imaginary field, while information pathways refers to the sequences in which sources placed on the information source horizon are actually used. The empirical part of the study draws on semi-structured interviews with 18 individuals active in environmental issues. Human sources and the Internet were preferred most strongly in seeking for problem-based information. The major source preferences were content of information, and availability and accessibility. Usability of information sources and user characteristics were mentioned less frequently as preference criteria. Typically, information pathways consisted of the use of 3–4 sources. On average, human and networked sources were favored in the early phases of information seeking. Printed media such as magazines and organizational sources were often used to complement information received from human sources and the Internet. However, the source preferences varied considerably, depending on the requirements of the problem at hand. 相似文献
70.
Christian Thue Bjørndal Lars Tore Ronglan Svein S. Andersen 《Sport, Education and Society》2017,22(7):864-877
Structured talent identification and development, it has been argued, is one of the foundations of international sporting success and many modern elite sport systems have applied normative talent development (TD) models. The success of Norwegian handball, however, is based on an alternative approach to TD. Norwegian handball is characterized by a heterarchical organizational structure in which several key actors function highly autonomously. The aim of this article is three-fold: (a) to describe the organization of TD in Norwegian handball, (b) to identify how the inherent organizational characteristics of Norwegian handball have influenced the TD processes used and (c) to discuss if contemporary TD models provide an adequate conceptualization of the model used in Norwegian handball. This case study includes three units of analysis: (i) the overall organizational structure of Norwegian handball, (ii) the characteristics of the key actors involved and (iii) the inter-communication and collaborations of the key actors. The data sources were (a) documents and (b) interviews with 11 key informants. The informants were selected strategically to represent experienced coaches and professionals from multiple organizational units. The National Handball Federation uses a broad-based model for TD: 23% of male handball players and 15% of female handball players from the age of 13–17 years participate in regional-level initiatives in addition to practising daily in community-based volunteer sport clubs and sport schools. Findings reveal that the broad base of TD initiatives creates multiple access points to the talent pipeline for adolescents. However, because the heterarchical structure involves many actors, the unintended consequences are often related to (im)properly managing training and competition loads. There is a need therefore for well-developed coordination mechanisms and good communication between the key actors involved. 相似文献