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61.
62.
Damage caused by the earthquake of 7 December 1986 (M = 5.7) and its aftershocks in low-storey residential buildings in the town of Strazhitza, Bulgaria, situated in the epicentral zone are systematized. A scale of damages is compiled for two types of buildings which is coordinated with the MSK-64 scale. The territorial distribution of the seismic intensity is compared with the results of the detailed engineering-geological study. A correlation between the Quarternary deposit thickness and the observed seismic intensity is obtained.Paper presented at the 21st general assembly of the European Seismological Commission held in Sofia, 1988. 相似文献
63.
The establishment of local self-government was a key part of the post-1989 transformation in East and Central Europe. Local
government in both Western and East and Central Europe has increasingly been expected to play a role in local economic development
(LED). Local government is one important agent in the complex processes of building 'institutional thickness' to ensure the
development of local economies and the quality of life of inhabitants. This paper presents the results of a national postal
questionnaire survey of the LED role of the lowest level of local self-government in Poland, the gmina or commune. The paper
establishes a baseline of knowledge regarding: the local economic problems faced by communes; their attitudinal, strategic
and organisational responses; and the main factors which are hindering the communes' LED role.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
64.
Prediction of threshold conditions and incipient motion is the essential issue for the study of sediment transport. This work compares existing empirical threshold curves proposed for Shields diagram, a method based on the concept of probability of sediment movement, and an empirical method based on movability number. These methods are used to predict the incipient motion conditions for experimental runs taken from various studies. Most of the experimental data, used in this work, have not been used before in derivation of alternative formulations for Shields diagram and other methods. The empirical threshold curves based on the Shields entrainment function was the least successful at predicting the measured incipient motion conditions, while the use of the movability number gives good predictions of critical shear velocity compared with experimental data. 相似文献
65.
根据新编制的1:200万重磁资料分析,中国北部深层存在东、中、西3个构造区,其东界在贺兰山-六盘山-龙门山一线,西界在星星峡-若羌一线.由此可见,东部范围包括华北-东部地区;中部包括蒙甘青地区;西部为塔里木-准噶尔地区.东、西部由中国最古老的2个太古代-早元古代稳定地块组成,而中部是元古代地块区,因受青藏高原的推挤,活动性较大.同时认为,原定的界线--大兴安岭-太行山-武陵山断裂仅发生在东部构造区内,构不成分区界线. 相似文献
66.
黑土层厚度是评价东北黑土区土壤质量的重要参数,但其厚度的空间分布及多年变化情况仍然不够明确.针对东北黑土区第二次土壤普查的61处典型土壤剖面进行了现状实地调查,并对黑土层厚度变化进行了对比分析.结果表明:近40年来,东北黑土区黑土层厚度平均减少了12cm,平均减薄速度为0.32cm/a.四省(区)黑土层减薄厚度具有显著差异,表现为吉林(23.65cm)>辽宁(11.83cm)>内蒙古(10.33cm)>黑龙江(6.83cm).吉林省黑土层减薄厚度和比例最大,生态风险最为严峻.吉林省黑土层厚度变化值与气温升高值呈显著的负相关关系,表明随着气候变暖,土壤有机质下降明显,黑土层的厚度也呈减薄趋势.研究表明,水蚀作用也是黑土层厚度减薄的重要影响因素.未来应加强黑土层厚度判定和黑土层厚度空间制图等方面研究,对指导黑土地保护利用具有重要意义. 相似文献
67.
通过重力异常分解模型,选用小波基函数“bior3.7”,分解得出青藏高原东北缘布格重力异常资料的小波4阶近似成分,利用其主要由莫霍面产生的布格重力异常,以6条人工地震剖面信息做初始控制条件,反演得出青藏高原东北缘的地壳厚度。 相似文献
68.
台湾及其邻海的重力特征与构造、地震的关系 总被引:1,自引:0,他引:1
分析认为,在台湾及其邻海的重力场中,具有短波长特征的空间重力异常受地形与海深所制约.玉山的200×10 相似文献
69.
Interannual variability(IAV) in the barrier layer thickness(BLT) and forcing mechanisms in the eastern equatorial Indian Ocean(EEIO) and Bay of Bengal(BoB) are examined using monthly Argo data sets during 2002–2017. The BLT during November–January(NDJ) in the EEIO shows strong IAV, which is associated with the Indian Ocean dipole mode(IOD), with the IOD leading the BLT by two months. During the negative IOD phase, the westerly wind anomalies driving the downwelling Kelvin waves increase the isothermal layer depth(ILD). Moreover, the variability in the mixed layer depth(MLD) is complex. Affected by the Wyrtki jet, the MLD presents negative anomalies west of 85°E and strong positive anomalies between 85°E and 93°E. Therefore, the BLT shows positive anomalies except between 86°E and 92°E in the EEIO. Additionally, the IAV in the BLT during December–February(DJF) in the BoB is also investigated. In the eastern and northeastern BoB, the IAV in the BLT is remotely forced by equatorial zonal wind stress anomalies associated with the El Ni?o-Southern Oscillation(ENSO). In the western BoB, the regional surface wind forcing-related ENSO modulates the BLT variations. 相似文献
70.
泊松比做为了解地球内部介质一个非常重要的参数,在地震学上可以通过P波和S波速度的比值来确定.利用远震P波波形记录中包含的壳-幔速度间断面的Ps转换波及其多次反射/转换波信息,采用在地壳厚度-波速比平面上对接收函数转换波能量的叠加搜索方法,可以测定台站下方区域内地壳的平均厚度和泊松比.我们对渤海湾盆地北西盆山边界地区68个宽频带台站近两年的远震记录资料进行了处理研究,得到了该区域的地壳厚度以及泊松比分布.结果表明,渤海湾盆地北西盆山边界的泊松比值分布横向变化复杂, 山区侧与盆地侧存在明显差异;山区侧泊松比值分布相对均匀,盆地侧变化剧烈,但存在小区域范围内(100~200km)的一致性,与地表出露岩石的对比表明:形成渤海湾盆地的新生代伸展作用在下地壳深度有明显的响应,从地震学上获得的泊松比分布对于了解该地区地壳物质组成可起到很好的约束作用. 相似文献