煤中有机质二次生烃迟滞性及其反应动力学机制   总被引：25，自引：1，他引：24       下载免费PDF全文

秦勇  张有生 《地球科学》2000,25(3):278-282

采用自然成熟度系列与其预热残渣系列样品相结合方式, 通过热解模拟方法, 对煤中有机质二次生烃迟滞性显现特征和化学反应动力学机制进行了探讨.结果表明: 二次生烃起始成熟度增高, 二次生烃峰位成熟度呈规律性后移, 二次生烃作用“死线”位于R_o=4.0 %左右; 二次生烃峰位成熟度与起始成熟度之差随起始成熟度的增高呈抛物线式演化, 二次生烃的绝对迟滞性和相对迟滞性均呈阶段性演化, 由此可对二次生烃迟滞深度进行预测; 二次生烃半峰宽随起始成熟度呈阶段性演化, 暗示二次生烃起始成熟度位于生油高峰附近的烃源岩, 其生烃量可能相对较大.同时, 原始样品平均活化能的演化经历了4个阶段, 它们与热解生烃量及二次生烃迟滞性的阶段性演化特征高度吻合, 揭示出二次生烃作用严格受控于反应动力学的地球化学机制.   相似文献   

沥青质傅里叶变换红外光谱 (FT IR)分析及其在有机地球化学研究中的应用   总被引：5，自引：0，他引：5  

廖泽文  耿安松 《地球化学》2001,30(5):433-438

沥青质傅里叶变换红外光谱（FT－IR）分析可以反映出其分子结构上的特征，红外吸收因子Z[I(1380cm^-1)/I(720cm^-1）]能指示不同来源沥青质的母质类型；吸收因子Y[I(1600cm^-1)/I(1450cm^-1)]可以较好地讨论沥青质的成熟度演化状况；沥青质的红外研究认为，所有的沥青质都具有较好的再生烃潜力，其中Ⅲ型母质来源的沥青质具有较好的再生气潜力。而Ⅰ和Ⅱ型母质来源的沥青质具有高的再生油潜力。  相似文献   

The history of the development of procedures for the rapid assessment of environmental conditions to aid the urban regeneration process at London Docklands     

A. F. Howland 《Engineering Geology》2001,60(1-4):117-125

A process of urban regeneration of the former industrial dock area of east London by the London Docklands Development Corporation (LDDC) recognised the importance of geotechnical and geoenvironmental information. A systematic programme of data collection was implemented and stored in a series of bespoke computer database systems and cartographic registers. These allowed retrieval and manipulation of the data to provide rapid site assessments. The understanding of the natural setting of the area was enhanced as a consequence of the collation exercise. The data stored included geotechnical and environmental information on soil and groundwater. The hydrogeological regime was modelled by computer to determine the consequences of development on groundwater movement. In addition, a cartographic register of historic land use was developed. This gave instant detail on the potential for contamination of a site and became a fundamental tool in the UK planning process of the area. The information from the separate systems was finally combined into a geographic information system.  相似文献   

东北平原农田防护林网区土地资源系统结构及动态   总被引：2，自引：0，他引：2  

张柏 《地理学报》1992,47(4):324-343

本文在对东北平原农田防护林网区土地资源系统基本结构分析的基础上,利用典型区域的数据对该土地资源系统动态进行分析。本区的土地资源系统进入广泛的农业开发时间仅五、六十年,但经过强人工作用,已从垦殖期转入衰竭期。只有以人工再生(高投入)的方式才能保证土地资源的永续利用,维持系统的良性循环。否则,仅仅依赖自然再生(低投入)为主要的物质能量返回形式,必然导致粮畜生产带走物质能量,造成土地肥力得不到必要补充,形成土地资源日益衰竭的恶性循环系统。  相似文献   

What controls levels of dissolved phosphate and ammonium in surface waters?   总被引：4，自引：0，他引：4  

Walter K. Dodds 《Aquatic Sciences - Research Across Boundaries》1993,55(2):132-142

Dissolved inorganic nutrient pools are small relative to particulate pools, and dissolved pools turnover rapidly. It has been observed that pools change little from day to day on the sampling scales usually employed. A simple model is presented where uptake and regeneration rates balance to cause a local steady state concentration for dissolved inorganic nutrients. Enrichment and dilution perturbation experiments with lake water support the idea of steady state nutrient concentrations. Although inorganic nutrient concentrations are often controlled by biota, the absolute concentrations present tell little about the activity of that biota.  相似文献   

生长前期三疣梭子蟹(Portunus trituberculatus)附肢再生系统解析及阶段划分     

付媛媛  刘磊  母昌考  朱芳  任志明  李荣华  宋微微  王春琳 《海洋与湖沼》2017,48(5):1084-1091

以三疣梭子蟹(Portunus trituberculatus)第Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ期幼蟹为材料,采用组织切片等方法研究其大螯断肢后再生生长规律。结果表明,第Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ期幼蟹大螯一次蜕壳再生率分别为59.9%,75.3%,74.2%,80.4%,69.5%;断肢组存活率分别为89.4%,84.9%,85.2%,89.4%和74.2%,均低于对照组的98.2%,90.3%,95.1%,90.2%和80.3%,但差异不显著(P0.05);第Ⅰ、Ⅱ、Ⅲ期断肢组在去大螯后平均蜕壳周期分别为3.33d、4.47d和6.27d,显著长于正常组的2.13d、3.89d和5.63d)(P0.05),而第Ⅳ、Ⅴ期断肢组平均蜕壳周期分别为7.12d和10.86d,极显著长于对照组的6.11d和8.09d(P0.01),且断肢个体的生长期越往后,断肢再生所需时间越长。本研究依据再生附肢发育特点将三疣梭子蟹大螯断肢再生划分为6个标志性发育阶段:再生芽基期、肢芽趾缝期、肢芽分化期、肢芽斑点期、肢芽成熟期、肢体出膜期;第Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ期蟹再生肢芽横纵比平均值分别达到0.32、0.318、0.398、0.518、0.538时,断肢幼蟹可以达到附肢出膜的临界点。综上所述,三疣梭子蟹断肢后能在1个蜕壳周期内完成大螯再生,第Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ期断肢幼蟹蜕壳周期时间显著高于正常幼蟹;断肢组成活率低于对照组,但差异不显著,第Ⅳ期幼蟹的再生率和存活率均最高;各期幼蟹断肢再生附肢均经过6个具有标志性事件的发育阶段;各期再生肢芽横纵比值具有一定临界值(0.32,0.318,0.398,0.518,0.538)。本研究首次对三疣梭子蟹断肢再生过程及再生能力进行了探究,结果将有助于甲壳类断肢再生机理的阐明。  相似文献   

丽江市古城周边“城中村”更新的社会经济发展策略研究     

欧莹莹 《云南地理环境研究》2013,(5):15-19

丽江作为历史文化名城旅游开发的成功案例,经济快速发展,近年来,古城的旅游市场已趋于饱和,其周边土地的开发活动频繁,“城中村”现象显现出来.以研究丽江古城周边“城中村”的更新改造为目标,针对丽江“城中村”的特殊性,从社会学的视角探讨古城周边“城中村”地区在更新过程中社会经济结构的转变,研究如何构筑城乡一体的新型经济、社会空间格局.  相似文献   

首钢京唐钢铁厂压缩空气供气系统的优化设计     

周玉磊 《中国勘察设计》2010,(8):74-76

通过首钢京唐钢铁厂的压缩空气供气系统的设计,探讨了在设计中所采用的优化及余热再生等节能技术,和所能达到的良好的经济效益。  相似文献   

Study on characteristics and regeneration rules of Salix gordejevii in Hunshandak Sandland, China     

XiuPing Cui  GuoHou Liu 《寒旱区科学》2012,4(5):0417-0421

Salix gordejevii, a species of dune-fixing pioneer shrub in the Hunshandak Sandland in China, plays a vital role in maintenance and improvement of the local ecological environment. Salix gordejevii has an r-type reproductive countermeasure, which means it produces large quantities of seeds that have a high germination rate but relatively low seedling viability. Our research on the seed regeneration and sprouting regeneration characteristics of Salix gordejevii shows that its sprouting regeneration process is more productive and efficient than its seed regeneration process. At the same time, growth of Salix gordejevii would decline when the drifting sand dune was fixed. To assess its sprouting regeneration process, we analyzed the number, length, and diameter of new shoots under different cutting treatments, and found significant differences based on various cutting heights and different cutting times (April vs. October). We conclude that cutting measures which take advantage of this species’ robust sprout tillering can increase the biomass of this shrub and also can improve its canopy density and its forage properties for livestock grazing, with the added benefits of improved sand-fixing and prevention of wind erosion.  相似文献   

Arsenic Removal from Natural Water Using Low Cost Granulated Adsorbents: A Review   总被引：1，自引：0，他引：1       下载免费PDF全文

Shams Ali Baig  Tiantian Sheng  Yunjun Hu  Jiang Xu  Xinhua Xu 《洁净——土壤、空气、水》2015,43(1):13-26

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