克氏原鳌虾气象因子影响研究现状与展望

克氏原螯虾主要养殖在长江中下游地区,目前最主要的养殖模式为虾稻共作模式。大量研究结果表明,克氏原螯虾的生长发育与气象要素密切相关。水温在25-30℃时,克氏原螯虾生长较快;16-25℃水温范围内,温度越高,越有利于雌虾卵巢发育;20-30℃水温范围内,水温越高,受精卵孵化时间越短。光明和黑暗时间之比为16 h∶8 h时,最有利于雌虾性腺发育。与克氏原螯虾养殖有关的气象灾害主要有暴雨洪涝、高温热害、低温冷害。鉴于目前的养殖和气象因子影响研究及服务现状,建议气象部门开展虾-稻种养基地气象观测站网建设,开展气温与水温相关性和水温预报研究,以及气象要素对克氏原螯虾影响的定量化研究。     

地理科学与资源科学的国家智库建设

地理科学与资源科学智库建设在地理科学与资源科学发展及学科建设中具有非常重要的战略地位。中国科学院地理科学与资源研究所建所80年来,地理科学与资源科学智库为传播人类文明、保障国家资源安全和持续利用、维护国家和全球可持续发展做出了重大贡献。本文回顾了80年来、尤其是2000年以来地理资源所在高端智库建设方面取得的辉煌成就,以时间为主线,总结了智库建设的重点领域及特色方向,包括综合科学考察与资源环境承载力评价、国家重大区划与规划、国情分析与区域可持续发展、新型城镇化与城市群建设、精准扶贫与乡村振兴、生态文明体制改革与美丽中国建设、“一带一路”建设与国家安全、生态环境保护与科技防灾减灾等方面研究和决策服务;提出要继续瞄准国家发展战略需求,继续提升智库建设在研究所发展与学科建设的战略地位、围绕国家“两个一百年”奋斗目标、对标SDGs实现国家可持续发展目标建好智库,围绕美丽中国与生态文明制度建设、国家重大区域发展战略和应急重大事件建好智库,强化地理模拟技术和智能化技术对智库建设的技术支撑,以智库建设推动地理科学与资源科学建设。力争通过5~10年努力,把研究所建成最具影响力的国家高端智库,成为生产智库产品和支撑国家发展决策的中坚力量。     

Effects of land use and cultivation time on soil organic and inorganic carbon storage in deep soils

The vertical distribution and exchange mechanisms of soil organic and inorganic carbon(SOC, SIC) play an important role in assessing carbon(C) cycling and budgets. However, the impact of land use through time for deep soil C(below 100 cm) is not well known. To investigate deep C storage under different land uses and evaluate how it changes with time, we collected soil samples to a depth of 500 cm in a soil profile in the Gutun watershed on the Chinese Loess Plateau(CLP); and determined SOC, SIC, and bulk density. The magnitude of SOC stocks in the 0–500 cm depth range fell into the following ranking: shrubland(17.2 kg m~(-2)) grassland(16.3 kg m~(-2)) forestland(15.2 kg m~(-2)) cropland(14.1 kg m~(-2)) gully land(6.4 kg m~(-2)). The ranking for SIC stocks were: grassland(104.1 kg m~(-2)) forestland(96.2 kg m~(-2)) shrubland(90.6 kg m~(-2)) cropland(82.4 kg m~(-2)) gully land(50.3 kg m~(-2)). Respective SOC and SIC stocks were at least 1.6-and 2.1-fold higher within the 100–500 cm depth range, as compared to the 0–100 cm depth range. Overall SOC and SIC stocks decreased significantly from the 5 th to the 15 th year of cultivation in croplands, and generally increased up to the 70 th year. Both SOC and SIC stocks showed a turning point at 15 years cultivation, which should be considered when evaluating soil C sequestration. Estimates of C stocks greatly depends on soil sampling depth, and understanding the influences of land use and time will improve soil productivity and conservation in regions with deep soils.     

全球地缘经济合作的空间模式与空间机理——基于商品贸易规模的实证研究

运用1996—2016年全球各国商品贸易规模的面板数据,借助探索性空间数据分析方法揭示全球地缘经济合作的空间模式,构建空间误差混合回归模型进一步解释全球地缘经济合作的空间机理,得出如下结论：① 全球地缘经济合作存在空间正相关,呈现出“核心-边缘”的空间模式,表现为板块化和多极化的发展趋势;② 全球地缘经济合作的空间依赖性受到生产要素流动与国际分工的传导与驱动,国家规模是地缘经济合作的基础因素,生产要素禀赋是地缘经济合作的内生动力,创新是地缘经济合作的引擎,政治脆弱性是地缘经济合作的壁垒,地缘经济合作的空间依赖性在创新要素跨国流动影响下趋于弱化;③ 中国需在空间上遵循“邻近国家-欧亚区域-全球范围”的三环递进原则,有层次地布局地缘经济资源,在内容上发挥规模优势和要素禀赋优势,强化科技创新国际竞争力,有差异地制定地缘经济政策,在策略上激发地缘经济对地缘政治的渗透效应,最大化地缘经济杠杆作用。     

惠民凹陷南坡石炭二叠系煤层二次生气模式

利用开放体系程序升温热模拟实验方法,对惠民凹陷南坡石炭—二叠系煤岩样品的热演化规律进行了研究,建立了该区石炭二叠系含煤地层有机质的生气模式,探讨了影响二次生气潜力的各种主控因素,为准确评价其资源潜力和计算远景资源量奠定了基础,对渤海湾盆地其他类似地区煤型气勘探具有指导意义。     

X荧光分析仪在地质工作中运用实例

X 荧光分析技术具有快速测定、适合野外作业、成本低、仪器轻便等特点。运用新型X 荧光仪进行样品分析,可以快速得到样品检测结果,以指导下步地质矿产勘查、工程施工等工作,大大加快工作进度、提高工程效率,对缩短地质矿产勘查周期有着重要意义。     

Identification of the Main Control Factors and Failure Modes for the Failure of Baiyuzui Landslide Control Project

Geotechnical and Geological Engineering - The failure of landslide control project presents a deformation that continues to develop along the crack system, and the continuous failure of mechanical...     

Mechanical behavior and micro-structure of cement kiln dust-stabilized expensive soil

In this study, the effects of cement kiln dust (CKD) on the swelling properties, strength properties, and microstructures of CKD-stabilized expansive soil were investigated. Samples were prepared and stabilized with different CKD content ratios, ranging from 0 to 18% by dry mass. The results obtained show that the maximum swelling pressures decrease exponentially with increases in CKD content. Both the cohesion and unconfined compressive strength (UCS) increase at ratios below 10% CKD and then decrease slightly, above that ratio. CKD can also improve the strength of saturated, expansive soil. There is no visible change of UCS for soil without CKD when cured, while the UCS of a sample with 10% CKD content after curing for 90 days is higher than that after curing for only 1 day. This indicates that CKD can improve the long-term strength of expansive soil. Finally, microstructure analysis reveals that the addition of CKD reduces the montmorillonite content of expansive soil and decreases its swelling properties. The addition of CKD also changes the pore volume distribution, both the size and amount of macro-pores and micro-pores decrease with increase in CKD content. For saturated samples, the size of macro-pores is obviously reduced, while that of micro-pores is slightly increased for both treated and untreated soils. Hydration and saturation processes make the soil structure become dispersive which results in a lower strength, and adding CKD can restrain this process. The suggested optimal CKD content is between 10 and 14% and with a curing time of more than 27 days.     

基于数学形态学的位场数据边缘增强方法

位场数据边缘增强对于地质构造研究和矿床勘查具有重要意义。现有的边缘增强方法多数基于位场数据的导数构建,往往存在对噪声敏感的缺点,且处理结果中常有虚假边界的出现。本文基于数学形态学良好的形状分析和噪声压制性能,通过数学形态学基本算子的组合叠加,提出了一种新的位场数据边缘增强方法。该方法容易实现,且不需要计算位场数据的水平和垂向导数。板状体模型试验结果表明,该方法能有效地对重力异常和化极后的磁异常数据进行边缘增强。针对三维模型试验中正负异常同时存在的情况,相比以往几种方法,该方法输出的边缘更清晰且没有额外边缘的产生,并表现出更强的抗噪能力。最后将该方法和以往几种方法应用到老挝万象地区实际重力异常数据的处理中,结果显示该方法刻画出的边缘更加连续清晰;同时结合以往地质资料,推断了成矿的有利部位。     

Swelling–shrinkage properties and soil improvement of compacted expansive soil, Ning-Liang Highway, China

In this paper, the swelling–shrinkage properties of the compacted expansive soil in the Huaiyin Section of the Ning-Lian Highway are introduced, and swelling–shrinkage mechanisms are discussed based on changes in soil water content, dry density, material composition and fabric. The improvement of the compacted expansive soil by lime is also discussed briefly. It is concluded that careful attention should be paid to this type of compacted expansive soil.