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991.
化学固沙材料在干旱沙漠地区的应用   总被引:16,自引:1,他引:16  
在查阅大量文献的基础上,探讨了化学固沙原理。通过实地试验,较系统地分析了常用的化学固沙材料、效果及在干旱沙漠地区应用化学固沙材料的适宜性。新型化学固沙材料及其特性的研究是当今化学固沙的重要内容。文章简要介绍了新型化学固沙材料的研究进展。SH为新型高分子材料,具有较高的强度、良好的耐水性、抗冻融和耐老化性能,成本低,喷洒工艺方便、简单,是固沙的理想产品。化学固沙快速方便,但防沙作用差,应开展化学-生物固沙一体化综合研究。固沙植被用新材料及低成本制备技术的研发,将在年降雨量只有数10mm的WN广大沙漠区防沙治沙中具有广阔的应用前景。  相似文献   
992.
中国陆地自然植被碳量空间分布特征探讨   总被引:66,自引:5,他引:61  
陆地生态系统在全球碳循环动力学中的作用受到越来越多的注意。目前中国森林覆盖率为1392% , 到本世纪末全国森林覆盖率将达到15% , 对全球碳平衡具有重要作用。但是,由于我国碳循环的基础研究比较落后,致使我国陆地生态系统的碳储量和净第一性生产力 (NPP) 碳量还没有被准确确定, 而且陆地生态系统的碳通量估计存在较大差异。  相似文献   
993.
作为华北克拉通周缘三条石墨成矿带之一的东部带,胶-辽-吉古元古代石墨成矿带是研究早前寒武纪石墨成矿机制及地球早期气候特征的天然实验室。本文对胶-辽-吉造山带辽河群石墨矿(甜水乡马沟石墨矿)进行了详细的岩相学、地球化学、拉曼光谱学以及碳同位素等方面的研究。研究结果表明辽河群含石墨矿岩石主要为含石墨变质杂砂岩、含石墨黑云母长英质片麻岩和含石墨透闪大理岩,在log(Fe2O3/K2O)-log(SiO2/Al2O3)判别图解中,这些含石墨岩石位于砂岩和页岩区域内,它们具有和太古宙后澳大利亚平均页岩(PAAS)相似的稀土元素特征;地球化学特征表明它们具有低的成熟度,未经历长途搬运,是快速堆积的产物,主要沉积于活动大陆边缘弧后盆地环境。碳同位素研究表明辽河群石墨矿碳同位素值具有很宽的变化范围(δ13CPDB=-16.49‰~-25.93‰),是有机物在变质过程中脱CH_4造成的。结合拉曼光谱学特征,我们认为辽河群石墨矿是由有机物经过变质作用形成的,其变质程度可以达到高角闪岩相(551~627℃)。综合分析前人年代学数据,我们认为辽河群石墨矿的沉积时代为2.13~2.17Ga,在后期的弧-陆碰撞造山以及后碰撞作用过程中(2000~1895Ma;1875~1850Ma),有机物逐渐发生变质形成石墨并聚集形成石墨矿床。华北克拉通周缘大量石墨矿的沉积时代(2.3~2.05Ga)和大氧化事件发生的时间一致,可能是地球早期大氧化事件的沉积响应。  相似文献   
994.
震旦纪—寒武纪转折期是地球演化的关键节点,这一时期的碳-氧同位素记录在塔里木保留完整却关注较少。选取苏盖特布拉克露头震旦系与寒武系交界地层实测采样,并开展了古生物、镜下鉴定、碳同位素漂移事件的综合分析,探讨了N1(BACE)、P1(ZHUCE)等碳同位素漂移事件的成因机制。样品的δ13Ccarbδ18Ocarb相关系数(R2=0.05)、δ18Ocarb和Mn/Sr相关系数(R2=0.09)及岩石学特征表明,后期成岩改造并未导致碳-氧同位素的显著分馏,原始碳同位素特征得以基本保留。由下至上,在该剖面识别出P-1事件(δ13Ccarb峰值1.9‰2.4‰)、N1事件(-6.8‰-10.3‰)、P1事件(1.4‰4.1‰)、N2a-c事件(-0.4‰-2.8‰)、P2a-c事件(0.2‰0.6‰)和N3事件(-3.4‰)。综合碳同位素演化特征与古生物、年代学数据,确认了玉尔吐斯组底部硅质页岩与奇格布拉克组顶部藻云岩的分界面为塔里木震旦系与寒武系的分界线,并实现了该露头与老林、肖滩、三峡、西伯利亚、阿曼和摩洛哥剖面的地层对比。分析认为,塔里木北缘震旦纪—寒武纪转折期的碳漂移事件,更多受控于古海洋氧气含量变化引起的固碳率forg的波动。玉尔吐斯组早期海侵背景下的大规模缺氧事件导致的初级生产力和固碳率降低,是N1负漂移事件(BACE)的主因;随后海退中氧气含量的增加引起生产力重建和固碳率增加,形成了P1正漂移事件(ZHUCE)。这一成果性认识有助于塔里木盆地寒武纪古环境研究与深层超深层油气远景资源评价。  相似文献   
995.
《China Geology》2021,4(4):720-746
Climate change is a common problem in human society. The Chinese government promises to peak carbon dioxide emissions by 2030 and strives to achieve carbon neutralization by 2060. The proposal of the goal of carbon peak and carbon neutralization has led China into the era of climate economy and set off a green change with both opportunities and challenges. On the basis of expounding the objectives and specific connotation of China’s carbon peak and carbon neutralization, this paper systematically discusses the main implementation path and the prospect of China’s carbon peak and carbon neutralization. China’s path to realizing carbon neutralization includes four directions: (1) in terms of carbon dioxide emission control: energy transformation path, energy conservation, and emission reduction path; (2) for increasing carbon sink: carbon capture, utilization, and storage path, ecological governance, and land greening path; (3) in key technology development: zero-carbon utilization, coal new energy coupling, carbon capture utilization and storage (CCUS), energy storage technology and other key technology paths required to achieve carbon peak and carbon neutralization; (4) from the angle of policy development: Formulate legal guarantees for the government to promote the carbon trading market; Formulate carbon emission standards for enterprises and increase publicity and education for individuals and society. Based on practicing the goal and path of carbon peak and carbon neutralization, China will vigorously develop low carbon and circular economy and promote green and high-quality economic development; speed up to enter the era of fossil resources and promoting energy transformation; accelerate the integrated innovation of green and low-carbon technologies and promote carbon neutrality.©2021 China Geology Editorial Office.  相似文献   
996.
Carbon pricing, including carbon taxes and emissions trading, has been adopted by different kinds of polities worldwide. Yet, beyond the increasing adoption over time, little is known about what polities – countries as well as sub- and supranational entities – adopt carbon pricing and why. This paper explores patterns of adoption (both implemented policies and those scheduled to be) through cluster analysis, with the purpose of investigating factors that could explain polities’ decisions to adopt carbon pricing. The study contributes empirically by studying carbon taxes and emissions trading together and by ordering the polities adopting carbon pricing into clusters. It also contributes theoretically, by exploring constellations of variables that drive the adoption of carbon pricing within individual clusters. We investigated 66 adopted policies of carbon pricing, which were divided into five clusters: early adopters, North-American subnational entities, Chinese pilot provinces, second-wave developed polities, and second-wave developing polities. The analysis indicates that the reasons for adopting carbon pricing have shifted over time. While international factors (climate commitments or influences from polities within the same region) are increasingly salient, domestic factors (including crises and income levels) were more important for the early adopters.

Key policy insights

  • Carbon pricing has become a global mainstream policy instrument.

  • Economic and fiscal crises provide windows of opportunity for promoting carbon pricing.

  • The international climate regime can support the adoption of carbon pricing through mitigation commitments and international financial and technical assistance.

  • Learning between polities from the same region is a useful tool for promoting carbon pricing.

  • Carbon intensive economies tend to prefer emissions trading over carbon taxes.

  相似文献   
997.
城市森林主要植被类型碳储量研究——以崇明岛为例   总被引:6,自引:0,他引:6  
王瑞静  赵敏  高峻 《地理科学》2011,31(4):490-494
以崇明岛为研究区域,采用野外样方调查和实验室模拟相结合方法,研究崇明岛主要植被类型碳储量。结果表明:(1) 崇明岛不同森林植被类型其碳储量是不同,从大到小的排序为水杉、柳杉,黑松等针叶树为主的植被,其次是阔叶树林,最后香樟林;(2) 崇明岛的植被碳储量的分布有很大的空间差异性,主要分布在河流两岸、道路两侧以及居民区等;(3) 崇明岛主要植被类型的碳储量为491 212.16 Mg,平均碳密度为18.70 Mg/hm2,低于中国和世界的平均水平;(4) 根据本研究结果和存在的问题,就未来的发展方向进行讨论。  相似文献   
998.
Reconstructing climate change quantitatively over millennial timescales is crucial for understanding the processes that affect the climate system. One of the best methods for producing high resolution, low error, quantitative summer air temperature reconstructions is through chironomid analyses. We analysed over 50 lakes from NW and W Iceland covering a range of environmental gradients in order to test whether the distribution of the Icelandic chironomid fauna was driven by summer temperature, or whether other environmental factors were more dominant. A range of analyses showed the main environmental controls on chironomid communities to be substrate (identified through loss-on-ignition and carbon content) and mean July air temperature, although other factors such as lake depth and lake area were also important. The nature of the Icelandic landscape, with numerous volcanic centres (many of which are covered by ice caps) that produce large quantities of ash, means that relative lake carbon content and summer air temperature do not co-vary, as they often do in other chironomid datasets within the Arctic as well as more temperate environments. As the chironomid–environment relationships are thus different in Iceland compared to other chironomid training sets, we suggest that using an Icelandic model is most appropriate for reconstructing past environmental change from fossil Icelandic datasets. Analogue matching of Icelandic fossil chironomid datasets with the Icelandic training set and another European chironomid training set support this assertion. Analyses of a range of chironomid-inferred temperature transfer functions suggest the best to be a two component WA-PLS model with r 2 jack = 0.66 and RMSEP = 1.095°C. Using this model, chironomid-inferred temperature reconstructions of early Holocene Icelandic sequences show the magnitude of temperature change compared to contemporary temperatures to be similar to other NW European chironomid sequences, suggesting that the predictive power of the model is good.  相似文献   
999.
BOTDR技术在边坡表面变形监测中的应用   总被引:1,自引:0,他引:1  
针对普通监测手段和技术应用上的不足,采用BOTDR技术监测坡体表面变形发展。分析了监测实施过程中光纤传感器的固定及温度补偿问题,介绍了BOTDR在浙江省龙丽高速公路官家滑坡中的铺设手段。根据官家滑坡的工程环境特点,在坡体上采用植入式固定方式;前缘坡面布设光纤时,引入准分布式监测理念,使用专用夹具定点固定光纤。现场监测结果表明:植入式固定方式,宜选用外径较小的紧套光纤,能使其较好地保持同步协调变形,且光纤因护套影响小而灵敏性较高;定点固定方式,易选用外径较大的光纤,适宜于坡面监测环境。植入式固定方式,若坡体内温度场变化较小,可不进行温度补偿;若坡面温度变化较大,可选取与监测环境温度场相似区布设松套光纤进行温度补偿。对监测过程中实施光纤的固定及温度补偿手段进行了改进讨论。  相似文献   
1000.
In 2008, the very extensive tropical peats were estimated to be about 182 million ha spanning South America, Asia and Africa. About 20.3%(36.9 million ha) of this area exist in Asia. Peats are classified based on their degree of decomposition, namely Fibrists, Hemists, Saprists and Folists. This makes them different in characteristics. The activities of microorganisms vary in different types of peat due to, for example, the sapric layer of well humified peat can provide water and food to microorganisms during heat stress. In another scenario, deeper peat is older and typically has lower levels of labile carbon to provide substrate for microbes compared to surface peat. A complete understanding of the microbial communities in different layers of peat is essential as microorganisms play major roles in peat decomposition and are important to ecosystem processes. These peats are a very important global carbon(C)store or reserve and could severely impact climate change if not managed well. Peatlands can store as much as 40 to 90 Gt C. Mis-management of peats could severely impact the environment particularly the emission of carbon into the atmosphere. For instance, clearing of peatlands using fire has been reported to release an estimated 88 t C ha~(-1) to the atmosphere. There are several factors which influence the environmental consequences of tropical peat especially in relation to climate change. The main influences are:(i) changes in temperature,(ii) changes in precipitation or rainfall,(iii) changes in atmospheric composition, and(iv) fire and haze. This paper is a brief review on these four influences in relation to climate change. It is apparent from the brief review that there is a need for continued short and long-term research to better understand tropical peats and how they affect our climate. This will hopefully provide the basis for predicting better what could happen under various scenarios.  相似文献   
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