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1.
Freshwater ecosystem service is essential to human’s survival and development. Many studies have documented the spatial differences in the supply and demand of ecosystem services and proposed the concept of ecosystem services flows. However, few studies characterize freshwater ecosystem service flow quantitatively. Therefore, our paper aims to quantify the effects of freshwater ecosystem service flow on downstream areas. We developed a freshwater ecosystem service flow model and applied it in the Beijing–Tianjin–Hebei (BTH) region, China, for the year of 2000, 2005, and 2010. We assessed the regional water security with an improved freshwater security index by integrating freshwater service provision, consumption and flow; and found that most areas of the BTH region (69.2%) were affected by upstream freshwater flows. The areas achieving water security in the region also expanded to 66.9%, 66.1%, and 71.3%, which were 6.4%, 6.8% and 5.7% increments compared to no-flow situation, in 2000, 2005 and 2010, respectively. Setting quota for human water consumption is suggested to further improve water security. These results highlight the need to fully understand the connections between distant freshwater ecosystem service provision and local freshwater ecosystem service consumption. This approach may also help managers to choose more sustainable strategies for critical freshwater resource management across different regions.  相似文献   
2.
天津市种子植物区系成分分析   总被引:5,自引:0,他引:5  
沙汀  张文辉  刘新成 《植物研究》2009,29(1):96-102
天津市共有种子植物1 471种(含种下等级),隶属于720属140科,其中裸子植物7科、10属、16种;被子植物133科、710属、1 455种。另外,具有中国特有属11属。通过对天津种子植物区系的组成、地理成分、区系特征进行分析,得出主要结论如下:种子植物较丰富;植物区系起源古老,但也具有年轻性;区系成分复杂,特别是北温带成分占优势,但是在温带地区内有大比例的热带、亚热带属种的出现,说明本植物区系有着更为喜暖的祖先;多种区系成分汇集,与周邻联系广泛,地理成分以华北成分为主。  相似文献   
3.
天津七里海湿地蛾类多样性   总被引:24,自引:2,他引:22  
系统调查研究了天津七里海湿地的蛾类,已知19科153属198种,并对其多样性作了分析。结果表明,种 多度关系符合对数正态分布模型。但多样性指数与均匀度不相一致(r =-0.47),而与物种丰富度一致(r=0.95)。研究认为七里海湿地环境条件比较好,但有退化的趋势。  相似文献   
4.
生态水文调节服务是生态系统服务的重要组成,能够有效调节地表径流,缓解暴雨洪涝灾害。但由于城市建设扩张、生态环境退化、极端降雨频发等因素,导致生态水文调节服务出现供需失衡。平原城市中地形水动力较弱及城市发展需求高的特征更是加剧了这种现象。基于生态系统供需视角,以生态水文调节率表征城市生态水文调节服务的生态供给,以暴雨洪涝风险表征城市生态水文调节服务的社会需求,构建应对暴雨洪涝灾害的平原城市生态水文调节服务供需研究框架。以典型平原城市天津市为例,应用SWAT模型、随机森林模型和ArcGIS定量测度城市生态水文调节服务供需水平,划分四种供需空间匹配类型,识别供需失衡关键区域,并进行五级规划干预等级分区。结果表明:(1)供给能力呈现“东南沿海高,西北近山低”的空间分布;需求水平表现出“多中心聚集,圈层向外递减”的分布规律。(2)供需空间分布呈现正相关关系,低供-低需在四种供需匹配类型中占据主导,同时空间聚集性最明显。(3)规划干预分区存在明显的空间差异,优先干预区占比5.41%,整体与建成区分布一致,大部分集中在市内六区,其次分布在滨海新区核心区,是未来规划治理的重点。研究结果为城市规划管理从...  相似文献   
5.
结扎大鼠一侧输尿管,复制肾盂积水模型。在冷光源-光导纤维-导光棒的透射照明下,通过显微电视系统,成功地观察到完整肾脏皮质表层肾小球及其周围血管微血流动态的清晰图像。正常肾小球呈树状分布,密集、大小均匀。高倍镜下可清楚辨认入球及出球小动脉,其血细胞流态为直线状。并发现肾小球有交替开放现象。  相似文献   
6.
高福 《生物工程学报》2022,38(11):4012-4018
作为国家级研究机构,中国科学院各级研究所一直以来的重要使命就是心系国家事、肩扛国家责、永做国家人,站在国际科学发展前沿的高度,紧抓国家社会发展中重大需求的科学与技术问题,布局研究所及其项目和吸引人才。本文以个人视角,回顾了2004年回国接任微生物研究所所长后,开始思考工业生物技术的发展,布局天津研发中心,经过多年努力,在院党组的领导与支持下,中国科学院天津工业生物技术研究所建成,已经取得了重要成果;还回顾了建所初衷和早期成长发展历程以及与微生物研究所的关系。通过思考科学、技术、工程(医学)之间的关系,提出从事基础科学研究的科研人员进行转化应用的路径,即“想法-假说-实验-概念-论文-技术-样品-产品-商品”的9层逻辑关系,希望科学家能够做出解决实际问题的实用工作,并展望了未来工业生物技术的远景。  相似文献   
7.
武汉和天津园林植物叶片热值比较研究   总被引:9,自引:0,他引:9  
对天津和武汉两地一些园林植物叶片的春季干重热值、灰分含量和去灰分热值进行了比较 ,结果发现 ,无论在武汉还是天津 ,所测园林植物的干重热值均表现为乔木 >灌木 >草本的递减趋势 ,灰分含量则呈现相反的趋势即草本 >灌木 >乔木 ,去灰分热值在武汉与干重热值的趋势一致 ,但在天津却是乔木 >草本 >灌木。同一类型的植物干重热值都是低纬度的武汉高于高纬度的天津 ,灰分含量相反 :天津高于武汉 ;乔木和灌木的去灰分热值也是武汉高于天津 ,草本植物例外。两地共有的 7种植物平均值相比 ,干重热值和去灰分热值都是武汉 >天津 ,同一植物种相比 ,7种植物中 ,有 5种植物的干重热值和去灰分热值的地区差异与平均值一致 ,即武汉 >天津 ,只有刺槐和白三叶例外。  相似文献   
8.
A series of sulfonylurea derivatives containing a 2,6-disubstituted aryl moiety were designed, synthesized and evaluated for their herbicidal activities. Most of these compounds showed excellent inhibitory rates against both monocotyledonous and dicotyledonous weeds, especially 10a, 10h and 10i. They exhibited equivalent or superior herbicidal efficiency than commercial chlorsulfuron at the dosage of 15 g/ha and the preliminary SAR was summarized. In order to illuminate the molecular mechanism of several potent compounds, their apparent inhibition constant (Kiapp) of Arabidopsis thaliana acetohydroxyacid synthase (AHAS) were determined and the results confirmed that these compounds were all potent AHAS inhibitors. 10i have a Kiapp of 11.5 nM, which is about 4 times as potent as chlorsulfuron (52.4 nM).  相似文献   
9.
With the rapid development of social and economic conditions in the Beijing–Tianjin–Hebei (BTH) collaborative development region in China, the water-environmental problems gradually evolve into a regional problem. As an important tool of predicting and preventing these problems, water-environmental risk assessment (WERA) plays an increasingly important role in environment management. This study mainly targets the surface water environment and takes the BTH region as a study area in developing a water-environmental risk assessment index system based on the Driving force-Pressures-States-Impacts-Responses model. The weighting, risk, and zoning of each index are determined using multiple methods such as the Analytic Hierarchy Process, fuzzy comprehensive evaluation, and geographic information system technology. Further discussions are made to analyze the leading factors of high-risk units, the relationship between the risk level and social economy, and the uncertainty of WERA. Generally speaking, results show that the relative high-risk areas mainly distribute in Beijing, Tianjin, Shijiazhuang, and Tangshan, and the relative low-risk areas mainly distribute in Chengde and Zhangjiakou. The remaining parts of the region are at the middle-risk level. The results also show a positive correlation between the risk level and the social economy. This study gathered lots of data and carried out a number of calculation work, and is expected to improve the WERA methods and help managers set the priorities for local water-environmental management and make more effective decisions in the context of BTH collaborative development.  相似文献   
10.
Sendai virus strain Tianjin, a novel genotype of Sendai virus, has been proven to possess potent antitumor effect on certain cancer cell types although inactivated by ultraviolet (UV). This study was carried out to investigate the in vitro anticancer properties of UV-inactivated Sendai virus strain Tianjin (UV-Tianjin) on human osteosarcoma cells and the underlying molecular mechanism. Our studies demonstrated UV-Tianjin significantly inhibited the viability of human osteosarcoma cell lines and triggered apoptosis through activation of both extrinsic and intrinsic pathways in MG-63 cells. Meanwhile, autophagy occurred in UV-Tianjin-treated cells. Blockade of autophagy with 3-methyladenine remarkably attenuated the inhibition of cell proliferation by UV-Tianjin, suggesting that UV-Tianjin-induced autophagy may be contributing to cell death. Furthermore, UV-Tianjin induced reactive oxygen species (ROS) production, which was involved in the execution of MG-63 cell apoptosis and autophagy, as evidenced by the result that treatment of N-acetyl-L-cysteine, a ROS scavenger, attenuated both apoptosis and autophagy. In addition, inhibition of apoptosis promoted autophagy, whereas suppression of autophagy attenuated apoptosis. Our results suggest that UV-Tianjin triggers apoptosis and autophagic cell death via generation of the ROS in MG-63 cells, which might provide important insights into the effectiveness of novel strategies for osteosarcoma therapy.  相似文献   
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