煤矿复采量与动用量和“三率”关系研究     

张传龙 《中国煤炭地质》2011,(9):27-31

通过分析煤炭资源复采量、复损量与当期（年）动用量、历年累计动用量、当期（年）采出量、当期（年）损失量之间的关系,提出了复采量计算公式,并阐述了复采量与生产矿井＂三率＂之间的关系。分析认为复采量参与当期（年）＂三率＂计算,能够确保当期（年）＂三率＂统计的真实性、准确性、合理性,从而提升煤炭资源储量管理水平和质量,同时建议修订生产矿井储量管理规程、矿井地质规范。  相似文献   

我国粮食生产与流通市场化问题探讨     

刘东昌 《地域研究与开发》2004,23(2):42-46

文章强调我国解决"三农"问题的焦点是粮食生产流通体制的改革。在我国当前存在的多个严峻条件的刚性约束之下,粮食的生产流通改革必须按市场经济规律进行。以对粮食生产流通所需要素的科学评估为依据,以粮食流通体制的改革为核心,以按市场化机制运行的各类企业为市场主体,以政府的引导和扶持政策为基本保障,形成良性运行模式,以尽快解决对粮食主产区农民的组织问题,达到粮食生产及流通直接与市场对接的目的。  相似文献   

河南省绿色农业发展对策研究   总被引：3，自引：0，他引：3  

周旗  张宏伟 《地域研究与开发》2005,24(3):95-98

河南省是我国重要的农产品生产基地,但有害成分含量过高是目前农产品在国内、国际市场缺乏竞争力的主要原因。河南省发展绿色农业的条件较好:农业生产的资源条件优越;形成了规模巨大、结构复杂的农业生产体系;交通便利,农产品交流市场活跃;无公害农产品品种多,规模大,市场占有率高。由于生态环境条件差别大,山区、丘陵和平原绿色农业发展的方向不同。加强绿色农业的组织建设、积极培育绿色农业的消费市场、加强农业生态环境建设、大力发展绿色食品产业、充分发挥绿色农业生产基地示范作用,是河南发展绿色农业的主要对策。  相似文献   

GEOCHEMISTRY     

《Abstract of Chinese Geological Literature》2014,(4)

正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861  相似文献   

Why are the continents just so…?     

M. SANDIFORD 《Journal of Metamorphic Geology》2010,28(6):569-577

Variations in gravitational potential energy contribute to the intraplate stress field thereby providing the means by which lithospheric density structure is communicated at the plate scale. In this light, the near equivalence in the gravitational potential energy of typical continental lithosphere with the mid‐ocean ridges is particularly intriguing. Assuming this equivalence is not simply a chance outcome of continental growth, it then probably involves long‐term modulation of the density configuration of the continents via stress regimes that are able to induce significant strains over geological time. Following this notion, this work explores the possibility that the emergence of a chemically, thermally and mechanically structured continental lithosphere reflects a set of thermally sensitive feedback mechanisms in response to Wilson cycle oscillatory forcing about an ambient stress state set by the mid‐ocean ridge system. Such a hypothesis requires the continents are weak enough to sustain long‐term (10⁸ years) strain rates of the order of ～10^?17 s^?1 as suggested by observations that continental lithosphere is almost everywhere critically stressed, by estimates of seismogenic strain rates in stable continental interiors such as Australia and by the low‐temperature thermochronological record of the continents that requires significant relief generation on the 10⁸ year time‐scale. Furthermore, this notion provides a mechanism that helps explain interpretations of recently published heat flow data that imply the distribution of heat‐producing elements within the continents may be tuned to produce a characteristic thermal regime at Moho depths.  相似文献   

GIS建库与地图制图一体化解决方案的设计与实现     

王殿坤  王峰 《测绘与空间地理信息》2010,33(1):100-103

GIS建库的目的是实现对空间数据的有效管理,满足空间分析、管理、规划和决策的需求,而地图制图关注的是地理要素的符号化表达,二者面向两种的不同需求。因此,在GIS建库的同时往往得不到符合制图规范的传统地图。本文深入分析建库数据模型和制图数据模型的特点,引入"建库与制图一体化"思想,实现从GIS数据到制图数据的信息补偿,基于SuperMap软件进行了实践,达到了"一库两用"的目的,避免了数据的重复建设。  相似文献   

Effects of preservatives on stable isotope analyses of four marine species     

Sirka Carabel  Patricia Verísimo  Juan Freire 《Estuarine, Coastal and Shelf Science》2009

The aim of the present study is to quantify the effect of formalin–ethanol preservation on the carbon and nitrogen stable isotope signatures of four taxonomical groups of marine species (Himanthalia elongata, Anemonia sulcata, Mytilus galloprovincialis and Patella vulgata). To examine temporal changes in the effects of preservation and to determine if preservation induced predictable shifts in δ¹³C and δ¹⁵N signatures, repeated analyses were carried out after 6, 12 and 24 months of preservation. Data from our study showed highly variable effects of the formalin–ethanol preservation on carbon and nitrogen isotope signatures between species. The use of a general correction factor was not possible, or else it should be species-specific. Differences in nitrogen isotopic values between preserved and unpreserved samples were minor compared to the assumed enrichment between trophic levels. The combined use of data from preserved and unpreserved samples could lead to biases in the estimation of the trophic level of organisms. Changes that preservatives caused in carbon values were variable between species and not always small enough to be ignored. So the use of data from preserved samples could change the interpretation of the mixing models used to determine the importance of multiple sources of carbon. In order to elucidate the effects that preservatives have in other species, further studies will be necessary.  相似文献   

罗汉果主要产区的农业地质调查研究     

曾其国  马小军  彭培好  冯世鑫  魏荣昌  黄曦  唐其  王晓峰 《物探化探计算技术》2012,34(4):464-469,369

通过对罗汉果在永福、临桂、龙胜县以喀斯特地貌为主产区进行环境地质调查和样地调查的综合调查方法进行调查可知:罗汉果种植的主要品种为青皮果;罗汉果种植在中元古界上板溪群(Pt12)和上元古界的震旦系并层湘桂边境组(Z);下古生界的前寒武纪混合花岗岩(γ2)和寒武系清溪组(∈q)、边溪组(∈b);上古生界的泥盆系莲花山组与那高岭组并层(D1)、郁江组与东岗岭阶并层(D2)山坡上和中生界的白垩系红色碎屑岩(K)的良田中。这些调查结果将对罗汉果的农业地质区划、生态环境效益、资源保护、农业地质区划、道地性研究和人工栽培提供农业地质学理论依据和实践指导。  相似文献   

光纤光栅技术在工程变形监测中的应用     

张廷玉 《测绘与空间地理信息》2013,36(6):196-197,201

介绍了光纤光栅技术在工程变形监测中的应用,简述了光纤光栅监测的技术原理及光纤光栅的制作方法。  相似文献   

微藻制氢的研究进展     

孟春晓  高政权  叶乃好 《海洋湖沼通报》2008,(4)

化石能源的不可再生性和使用过程中造成的环境污染使开发新能源变得非常迫切。氢是理想的能源,因此,利用微藻制氢具有诱人前景。本文综述了微藻光合制氢技术的研究历史、固氮酶和可逆产氢酶的产氢机制及研究进展;介绍了基于微藻的硫缺乏生理调控而发展起来的一步法与两步法光解制氢的方式;指出了利用微藻可逆产氢酶两步法间接光水解制氢最具开发潜力;分析了实现微藻光合制氢的限制因子和存在的问题;归纳了今后的主要研究方向。  相似文献