隆林县石漠化地区发展金银花种植气候适应性分析

以隆林县石漠化地区的气候条件为依据,采用比较分析方法,对金银花的气候生态规律和环境因子对金银花生长、产量的影响进行分析,找出其影响的气候指标。结果表明,隆林县石漠化地区金银花生长条件较好,西北部山区和南部高寒山区为适宜区,其它区域仅为次适宜区,为石漠化地区发展金银花种植提供气候依据。     

世界最大的泥炭地——俄罗斯瓦休甘泥炭沼泽

从全球泥炭地分布来看．大部分泥炭地集中在北半球亚寒带和寒温带地区,与最后一次大陆冰川后退残留的丘岗起伏的冰积地形和冰川湖群边缘地带相吻合。这些地区的气候和土壤条件有利于泥炭沼泽的形成和发育。处于这一地带的俄罗斯西西伯利亚、西北欧、北美五大湖以北到加拿大哈德逊湾泥炭沼泽十分发育。     

Analysis of raft foundation design based on considering influence of superstructure stiffness

The finite element method was used for analysis of raft foundation design in high-rise building. Compared with other conventional methods, this method is more adapted to the practical condition since both superstructure stiffness and soil conditions were considered in calculation. The calculation results by example show that the base reaction is more uniform and the maximum reaction decreases obviously. Accordingly, the raft foundation design is more economic without any loss of security for high-rise building.     

设计情景习题 增加练习趣味

复习课练习的设计，要注意为学生创设新的情景，促使学生回扣课本，使之对知识的理解上升到一个新高度。如商品粮基地的问题，从所属于湿地区、温度带、当地水源条件、土壤条件、社会经济条件以及人口、耕地面积和主要农产品等方面人手，设计成若干问题，使学生从更全面、更高层次的新角度，进行综合分析，可以避免机械重复。     

包气带增厚区土壤水力参数及其对入渗补给的影响

为探讨包气带深部增厚区土壤水力参数变化对入渗补给过程的影响,采用压力膜仪对河北正定深部包气带(8.0~21.0 m)10个原状土样进行水分特征曲线测试,利用RETC软件中Mualem-van Genuchten导水率模型对其拟合,获取含水率与非饱和导水率的关系曲线,并根据达西法对其进行分析讨论.结果表明:场地包气带深埋区的非饱和导水率为25~240 mm/a.当某一埋深历史水位下降速度越快,该埋深处相同含水率情况下土壤非饱和导水率越大,说明对应土层的入渗补给强度越大;因包气带厚度增大使原来位于饱水带的层状非均质土层转变为包气带,潜水位波动下降过程中深部包气带土层因排水压密作用,使得土壤水力特性发生变化,进而影响垂向入渗补给过程.      

太行山南端野皂荚群落优势种群的分布格局

根据野外调查的样方资料,应用方差/均值法(扩散系数)及其t检验、聚集指数、平均拥挤度、Green指数、聚集强度、Poisson分布和负二项分布的x2拟合检验等方法研究了山西太行山南端野皂荚群落优势种群的分布格局.结果表明:野皂荚、荆条、冰草和中亚苔草等具有较强的竞争能力和较宽的生态位而呈聚集分布,小叶鼠李、毛黄栌、黄刺梅和北柴胡等由于特殊的土壤条件、相对较弱的竞争能力和较窄的生态位而呈随机分布.方差/均值法及其t检验是一种较好的研究分布格局的方法,能很好地反映野皂荚群落中的优势种群的分布格局.     

Shaking Intensity Distribution of the April 14,2010 Yushu,China Earthquake

Two hours after the 2010 Yushu Earthquake, the shaking intensity distribution was obtained using the ShakeMap Rapid Generation System Based on Site Effects,developed by the author,which integrates the information of tectonic settings,the strike and scale of causative faults, focal mechanism solutions, fault rupture process and attenuation relationship in Western China,as well as local site effects. The results are as follows: ① The major axis of shaking intensity distribution is directed NW-SE,parallel to the Yushu fault; ② The meizoseismal area reaches an intensity Ⅸ and covers 300km2; ③ The intensity Ⅸ area is mainly distributed in the area 40km southeast and 15km northwest of the epicenter along the causative fault; ④ Due to local soil conditions,the northwestern part of the area with intensity Ⅸ on bedrock shows an intensity Ⅷ when converting from the bedrock to the soil; ⑤ Areas with intensity Ⅷ,Ⅶ,Ⅵ measure 3,000km2,8,000km2,and 24,000km2, respectively.     

Bi-normalized response spectral characteristics of the 1999 Chi-Chi earthquake

To develop uniform and seismic environment-dependent design spectrum, common acceleration response spectral characteristics need to be identified. In this paper, a bi-normalized response spectrum (BNRS) is proposed, which is defined as a spectrum of peak response acceleration normalized with respect to peak acceleration of the excitation plotted vs. the natural period of the system normalized with respect to the spectrum predominant period, Tp. Based on a statistical analysis of records from the 1999 Chi-Chi earthquake, the conventionally normalized response spectrum(NRS) and the BNRS are examined to account for the effects of soil conditions, epicentral distance, hanging wall and damping. It is found that compared to the NRS, the BNRS is much less dependent on these factors. Finally, some simple relationships between the BNRS for a specified damping ratio and that for a damping ratio of 5%, and between the spectra predominant period and epicentral distance for different soil types are provided.