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831.
针对多个县(市)、区土地调查文字材料将1:100万图号中的行、列号用错而产生严重缺陷的事实,本人认真学习了"国家基本比例尺地形图分幅和编号"的基础知识,并总结归纳出简易的快速判断正误的方法,以杜绝类似差错的发生. 相似文献
832.
摘要:后工业时代,文化资源的挖掘利用正日益成为各国政府引导城市更新、城市转型的重要手段。上海也积极利用各种文化资源来塑造国际文化大都市的形象。论文在回顾上海文化战略发展的基础上,分析了文化战略导向下上海对演出场馆资源的五种开发利用模式,并重点剖析了城市文化战略的实施对上海演出空间的塑造作用。在当前上海打造国际文化大都市的进程中,演出场馆的空间分布格局正日趋成形,同时,这种文化符号效力也带来了显著的空间效应,包括全球文化消费引领地的形成,艺术表演集聚区的初现以及演出空间的专业化拓展等。塑造与提升上海演艺文化空间格局成为上海加快建设国际文化大都市的必经之路。 相似文献
833.
运用密度泛函理论(DFT)在ωB97XD/gen (O、H元素Aug-cc-PVDZ; Rb元素Lanl2DZ)基组水平上研究了[Rb(H_2O)_n]~+(n=1~12)水合团簇的结构和光谱学性质。研究结果表明,通过分析气相和液相中的稳定能以及水合团簇可知,稳定构型出现在8配位的团簇中。第一配位层水分子数为8时形成Rb~+第一近似饱和水合层。此外,拉曼光谱显示[Rb(H_2O)_n]~+(n=1~12)水合团簇中O-H伸缩振动峰随着水分子数增加发生移动和加宽,Rb~+发生水合时,O-H对称和非对称伸缩振动发生红移,随着水合数的增多,频率蓝移。此外,文中对拉曼光谱中O-H振动的频率位置结合团簇结构进行了说明。 相似文献
834.
Beyond the Amazonian cities, distinct spatial units arranged in networks compose an extended urban space, usually invisible to government agencies and public polities. This article empirically reveals this space by studying the localities’ characteristics and connections. In southwestern Pará, Brazil, 236 communities were sampled using field expeditions. Variables related to the locality organization, history, health and education services, urban infrastructure, and land use were explored in a fuzzy cluster analysis. Local production and consumption flows were considered in the locality network analysis. The fuzzy analysis allowed identifying a hierarchy of localities for which the geographical location influences the spatial distribution patterns of five groups. On the other hand, consumption and production networks identified different locality's articulations, with persistent dependence on cities. These results characterize extensive urbanization at the local level and highlights the participation of the local populations configuring the Amazonian territory. 相似文献
835.
Caroline Faria Bisola Falola Jane Henderson Rebecca Maria Torres 《The Professional geographer》2019,71(2):364-376
Despite decades of recognition and worry about diversity, our discipline remains persistently white. That is, it is dominated by white bodies and it continues to conform to norms, practices, and ideologies of whiteness. This is a loss. At best, it limits the possibilities and impact of our work as geographers. At worst, it perpetuates harmful exclusions in our discipline: its working environments, its institutions, and its knowledge production. This remains deeply concerning for many geographers, and there has been important research, commentary, and institutional activity over the years. Yet, research shows us that little meaningful progress has been made. We know that mentoring is one vital part of the journey toward change. As such, we reflect here on our experience developing a research collective built on a transformative mentoring practice. We outline the key challenges, strategies, and tentative successes of the collective in supporting women of color undergraduate, graduate, and faculty geographers, arguing that such feminist formations are a vital part of the path to intellectual racial justice in our field. Key Words: diversity, feminist geography, higher education, mentoring, race. 相似文献
836.
以体长(1.932±0.204)cm、体质量(1.386±0.055)g的棘胸蛙蝌蚪为实验动物,在水温(24±0.2)℃、DO(7.30±0.01)mg/L、pH 7.30±0.01条件下,采用静水停食法开展了氨氮对蝌蚪的急性攻毒实验,并以此为基础,测定了不同氨氮质量浓度胁迫下棘胸蛙蝌蚪的排氨率、耗氧率、氧氮比及窒息点。结果表明:(1)蝌蚪对氨氮急性攻毒具明显的运动避毒行为,濒死个体的背部皮肤和肝脏均具明显的色变症状;(2)氨氮对蝌蚪的急性致死率具明显的剂量—时间效应,24h、48h、72h、96h LC50依次为177.5、151.7、148.6和146.8mg/L,毒性时段蓄积程度系数呈持续下降趋势,24—48h、48—72h、72—96h的时段MAC值分别为84.04%、10.1%和5.86%;(3)蝌蚪夜均、昼均、日均及时段排氨率随氨氮质量浓度增加均呈阶梯式下降趋势,其中时段排氨率与对照组均无显著差异的为9.80mg/L实验组,夜均、昼均、日均及时段排氨率与对照组均无显著差异的仅为2.45mg/L实验组(P0.05);(4)氨氮对蝌蚪呼吸耗氧具低毒兴奋效应,其夜均、昼均和日均耗氧率随氨氮质量浓度增加均呈先升后降趋势,峰值氨氮质量浓度范围均为4.90—7.35mg/L(P0.05),与对照组均无显著差异的仅为14.70mg/L实验组(P0.05),窒息点含氧量随氨氮质量浓度增加呈先降后升趋势,谷底出现于4.90mg/L实验组(P0.05),与对照组无显著差异的仅为9.80mg/L实验组(P0.05);(5)实验期间,蝌蚪氧氮比(O:N)波动于18.87—25.34之间,昼均和日均氧氮比(O:N)随氨氮质量浓度增加均依次呈"上升—稳定—下降—再稳定"之趋势,两者的峰值氨氮质量浓度范围分别为4.90—14.70mg/L和4.90—9.80mg/L,夜均氧氮比(O:N)呈先升后降趋势,峰值出现于7.35mg/L实验组(P0.05)。 相似文献
837.
利用2017年8-9月期间大连长兴岛海域实测遥感反射率、悬浮物浓度及GF-1 WFV数据,研究了该区域悬浮物浓度的遥感反演算法,发现遥感反射率与悬浮物浓度的散点图存在两种不同的变化趋势,将2008-2015年期间辽东湾内其它海域的数据与长兴岛海域数据进行叠加后,可初步推断产生两种变化趋势的主要原因在于疏浚区与非疏浚区悬浮物的粒径大小不同,导致其光学特性和反演算法也存在差异。将两种算法分别应用于2017年9月20日辽东湾及长兴岛近岸海域的GF-1 WFV4影像,发现采用非疏浚区算法反演长兴岛海域悬浮物浓度时,出现明显的低估现象,而疏浚区算法则能较好地反映出疏浚施工过程中悬浮物的分布规律,具有较好的工程应用价值。 相似文献
838.
SOXB作为重要的转录因子,参与了动物内胚层分化、消化道形成、神经细胞和感官细胞分化的调控。本研究利用RACE技术克隆了单环刺螠(Urechis unicinctus)2个soxb亚族基因soxb1(Uu-soxb1)和soxb2(Uu-soxb2)的cDNA全长序列,大小分别是1871 bp和2906 bp。在两个推导的氨基酸序列中均包含SOX家族的HMG-box结构和SOXB亚族蛋白特有的Group B homology序列,进化树分析它们分别与SOXB1和SOXB2聚类。原位杂交结果显示,Uu-soxb1和Uu-soxb2为母源表达基因;二者在担轮幼虫中的表达图式存在差异,其中早期担轮幼虫中Uu-soxb1 mRNA广泛分布于虫体中,Uu-soxb2 mRNA则集中于顶纤毛束基部和虫体后部(口后纤毛环之后),中期担轮幼虫中,Uu-soxb2阳性信号主要位于纤毛环及虫体的下半球;而Uu-soxb1 mRNA主要位于虫体下半球;之后的发育中二者的表达位点基本一致,即:晚期担轮幼虫中主要位于虫体后部,体节幼虫和蠕虫状幼虫中主要分布于消化道和体壁处。本研究结果表明,单环刺螠soxb在消化道发育过程中的表达模式与其他已报道动物类似,提示其在消化道发育中具有保守的功能。 相似文献
839.
CHIA Shir Reen CHEW Kit Wayne SHOW Pau Loke SIVAKUMAR Manickam LING Tau Chuan TAO Yang 《海洋湖沼学报(英文)》2019,(3):898-908
Microalgae,a sustainable source of multi beneficial components has been discovered and could be utilised in pharmaceutical,bioenergy and food applications.This study aims to investigate the sugaring-out effect on the recovery of protein from wet green microalga,Chlorella sorokiniana CY1 which was assisted with sonication.A comparison of monosaccharides and disaccharides as one of the phaseforming constituents shows that the monosaccharides,glucose was the most suitable sugar in forming the phases with acetonitrile to enhance the production of protein(52% of protein).The protein productivity of microalgae was found to be significantly influenced by the volume ratio of both phases,as the yield of protein increased to 77%.The interval time between the sonication as well as the sonication modes were influencing the protein productivity as well.The optimum protein productivity was obtained with 10s of resting time in between sonication.Pulse mode of sonication was suitable to break down the cell wall of microalgae compared to continuous mode as a lower protein yield was obtained with the application of continuous mode.The optimum condition for protein extraction were found as followed:200g/L glucose as bottom phase with volume ratio of 1:1.25,10s of resting time for ultrasonication,5s of ultrasonication in pulse mode and 0.25g of biomass weight.The high yield of protein about 81% could be obtained from microalgae which demonstrates the potential of this source and expected to play an important role in the future. 相似文献
840.
DOU Xiang MENG Fanping DUAN Weiyan LIU Qunqun LI Hao DU Shuhao PENG Xiaoling 《海洋湖沼学报(英文)》2019,(4):1342-1352
1-phenylethanol (1-PEA) is a flavor extensively used in the production of cosmetics, beverages, and food. The release of 1-PEA into coastal environments has aroused great concern. However, its potential effects on marine organisms are still unknown. In order to provide a better understanding of the ecological risks of 1-PEA in marine environments, this study determined the toxic effects of 1-PEA on two marine diatoms (Phaeodactylum tricornutum and Skeletonema costatum). The diatoms were grown in culture medium containing different concentrations of 1-PEA for 96 h. The contents of chlorophyll a, chlorophyll c, glutathione (GSH), malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were measured at the end of the exposure period. 1-PEA was shown to significantly inhibit the growth of diatoms, with 96-h EC50 values of 257.14 mg/Land 126.46 mg/L in P. tricornutum and S. costatum, respectively. In P. tricornutum, the levels of SOD, CAT, GPx, GSH, and MDA were stimulated only when 1-PEA concentrations were close to or greater than the 96-h EC50 value. However, in S. costatum, the activities of SOD and CAT, and the syntheses of two chlorophylls were inhibited even at an exposure concentration below the 96-h EC50 value. Taken together, these findings indicate a potential ecological risk by discharging 1-PEA into coastal areas and its species-specific toxic effects on marine organisms. 相似文献