连续流动分析法测定污水中阴离子表面活性剂、总氮、总磷、挥发酚、氰化物、硫化物的方法及实例     

刘倩  刘光学 《地下水》2008,30(3):40-43

快速同时测定排污口样品中阴离子表面活性剂、总氮、总磷、挥发酚、氰化物、硫化物的分析方法。采用连续流动分析法,确定最佳实验方案。经多次试验验证,呈良好线性关系;质量控制样品测定值均在保证值范围内,样品回收率在95．2％～104％之间,RSD小于2％。  相似文献   

甘肃胡杨恢复发展的限制因子及对策   总被引：20，自引：0，他引：20  

康向阳 《中国沙漠》1997,17(1):53-57

甘肃胡杨正处于负向演替的衰退状态,在现存的14590 hm²胡杨林中,衰退林和成熟林就占了73.0%,且大多为胡杨疏林;而树龄小于15年的幼龄林仅占了5.0%,1~5年生天然更新苗十分罕见。影响、限制甘肃胡杨天然林恢复发展的主要因子是林地水土环境的恶化;而胡杨无性繁殖困难、实生苗在生长形态方面表现参差不齐等因素,又限制了胡杨的人工发展。只有在突破胡杨无性繁殖难关的基础上,通过良种繁育调动群众营建人工胡杨林的积极性,才是恢复发展胡杨林的根本出路。  相似文献   

Seismogram Analysis of Indonesian Earthquakes at DAV Observation Station     

Bagus Jaya Santosa 《中国地震研究》2009,23(2):210-222

The S-wave velocity across the earth structure under Indonesia for Indonesia earthquakes has been investigated through seismogram analysis, simultaneously in the time domain and three Cartesian components. The data were recorded at DAV observational station, the Philippines. The main data set is the seismogram comparison between the measured and synthetic seismogram, instead of travel time data, as commonly used in other seismological research. The synthetic seismogram is calculated using the GEMINI method, which is equivalent to Mode Summation. The above seismogram comparison shows that the global earth mantle of PREMAN gives a deviating synthetic seismogram and has earlier arrival times than those of the measurement. The gradient of β_h in the upper mantle layers is altered into a positive, rather than negative slope as stated in the PREMAN model, and negative corrections are imposed to the zero order of the polynomials coefficients in all earth mantle layers. The excellent fitting, as well as travel time or waveform, is obtained from the surface waves of Love and Rayleigh, surface wave to the S and SS mantle waves as well as the core reflected waves. This result expresses that part of the earth mantle, due to a collision between India and Asia tectonic released zones, has a negative anomaly in S-wave velocity and vertical anisotropy in all of the earth mantle layers.  相似文献   

乌鲁木齐10号泉水汞短临前兆特征探讨   总被引：11，自引：3，他引：8  

高小其  许秋龙 《内陆地震》1999,13(1):72-77

从１０号泉地下水汞的地球化学特性入手,结合近５年来１０次震例,分析并初步总结了地下水水泵的短临前兆特征,水泵的短临异常的出现往往是突发性的;汞异常形态特征基本上具有一定重复性的正异常,仅有个别地震时出现负异常。映震范围;对５级以下地震,水汞异常范围约在６００ｋｍ以内,对５级地上地震,水汞异常范围约在３５０ｋｍ以内;对个别７级以上地震可能映震范围接近１０００ｋｍ。汞异常时间与发震;在前兆近场,往往在  相似文献   

Anchors in sand bed: delineation of rupture surface   总被引：4，自引：0，他引：4  

K. Ilamparuthi  K. Muthukrishnaiah 《Ocean Engineering》1999,26(12):373

Anchors of very large uplift capacities are required to support offshore structures at great water depths. The capacities of plate and mushroom type anchors are generally estimated based on the shape of rupture surface. An attempt has been made in the present investigation to delineate the rupture surfaces of anchors embedded in submerged and dry sand beds at various depths. The results exhibited two different modes of failure depending on the embedment ratio, namely, shallow and deep anchor behaviour. The load–displacement curves exhibited three- and two-phase behaviours for shallow and deep anchors, respectively. Negative pore water pressures recorded in submerged sand also exhibited variation similar to that of pullout load versus anchor displacement.  相似文献   

2016年门源MS6.4地震孕育—发生的地形变异常特征     

张希  秦姗兰  贾鹏  李瑞莎 《地震》2019,39(4):27-38

利用1999—2007年、 2009—2015年和2015—2017年即2016年1月21日门源M_S6.4地震前后的GPS水平运动资料, 以及震区周边200 km半径范围内跨断层流动短水准观测数据, 借助GPS视应变场计算、 冷龙岭断裂剖面的负位错反演, 以及跨断层形变强度新指标的提炼, 综合分析此次强震前相关断裂的中—长期闭锁背景以及断裂活动的中—短期动态演变过程。 结果显示: ① 2009—2015年相对1999—2007年, 祁连山构造区中东部GPS站点间差异运动和挤压变化增强; 跨断层短水准观测也显示震前2年左右时间内相似的断裂活动或形变应变加速特征。 ② 分层非均匀负位错反演揭示与地震相关的冷龙岭等断裂1999—2007年即震前十数年长期闭锁, 2009—2015年即震前6年半上—中层即地表以下0～15.6 km深度闭锁程度明显增大。 ③震区周边半径200 km内跨断层形变强度新指标显示出震前半年内逆断稍占优势的变幅加剧异常, 反映中短期前兆。  相似文献   

利用CryoSat-2卫星测高资料确定北极海冰干舷高     

吴星泉  张胜军  车德福 《测绘通报》2019,(7):64-68

卫星测高技术的发展使得大空间尺度探测海冰成为可能,海冰干舷高是反演海冰厚度的关键参量,获取精确的海冰干舷高对海冰探测及了解全球气候变化均具有重要的作用。本文基于近3年获取的CryoSat-2卫星SAR模式测高资料,在60°N—88°N纬度带内的北极海域通过设定阈值筛选可用的观测数据,并在此基础上计算2015—2017年间月平均海冰干舷高,最后通过IceBridge航飞数据的时空匹配验证了本文获取的干舷高计算结果是可靠的。  相似文献   

Bringing greenhouse gas removal down to earth: Stakeholder supply chain appraisals reveal complex challenges     

《Global Environmental Change》2021

Greenhouse gas removal (GGR) approaches are considered essential in several projections to meet the climate mitigation ambition of the Paris Agreement. Biomass Energy with Carbon Capture and Storage (BECCS) and afforestation are included extensively in mitigation scenarios but there are concerns about the feasibility of these approaches. This was explored with stakeholders from industry, non-governmental organisations (NGOs) and policy who were involved in interviews and a one-day participatory workshop. Multicriteria mapping (MCM) methodology was used to appraise the ‘real-world’ feasibility of four specific greenhouse gas removal supply chains at a granular level in the UK context. The MCM analysis shows that afforestation performs better in comparison to three BECCS supply chains, on criteria such as business model, social acceptability, and environmental sustainability. This innovative application of the MCM methodology enables the abstract representations of GGR in integrated assessment models to be explored at a more granular level through a supply chain analysis and thus gain a deeper understanding of the issues facing these approaches. The data gathered allows a wide range of technical, environmental, social and political criteria to be systematically applied in appraising the practical performance of different future implementation options for afforestation and BECCS. If these GGR supply chains are to become a reality on the scale required for 1.5 °C global warming, factors such as global cooperation, land availability, and the longevity of policies and incentives were found to be major challenges.  相似文献   

前陆冲断带的后期演化:负反转与再次冲断          下载免费PDF全文

马晓鸣何登发  吴晓智赵振宇 《地质科学》2010,45(4):1066-1077

和什托洛盖盆地位于准噶尔西北缘冲断推覆体之上,是一个在中生代由区域应力场性质发生改变时形成的负反转盆地。盆内沉积盖层厚度可达5000 m,由下侏罗统八道湾组、三工河组,中侏罗统西山窑组、头屯河组以及新生界组成。盆地内断裂发育,可划分为控制盆地格局和构造带展布的北东东向断裂和起调节作用的北西向断裂两组,依据分界断裂可将盆地划分出北部断褶带、中央坳陷带和南部斜坡带3个一级构造单元和7个二级构造单元。盆地的形成演化主要经历了3个时期：印支期在边界断裂不均衡冲断活动下形成盆地雏形; 燕山早期是盆地主要发育期,以大规模沉降作用为主; 燕山晚期-喜马拉雅山期是盆地的改造期,现今的构造格局基本形成并在喜马拉雅山期后定型。  相似文献   

Electrostatic ion-cyclotron waves in a plasma with heavy negative ions     

S.-H. Kim 《Planetary and Space Science》2008,56(11):1552-1559

Results of a laboratory study of electrostatic ion-cyclotron (EIC) waves in a plasma containing K⁺ (39 amu) positive ions, electrons and C₇F₁₄⁻ (350 amu) negative ions are presented. Excitation of the fundamental and higher harmonic light and heavy ion EIC modes was observed. The presence of heavy negative ions in the plasma has a significant effect on the excitation of the light ion EIC modes. The results may be relevant to the understanding of plasma wave properties in plasmas containing negative ions, such as those found in the Earth's ionosphere, the solar system, and, in particular, near Saturn's moon Titan, where an abundance of heavy negative ion species has recently been discovered [Coates, et al., 2007. Discovery of heavy negative ions in Titan's ionosphere. Geophys. Res. Lett. 34, L22103].  相似文献