Synthetic seismograms for finite sources in spherically symmetric Earth using normal-mode summation

Normal-mode summation is the most rapidly used method in calculating synthetic seismograms. How- ever, normal-mode summation is mostly applied to point sources. For earthquakes triggered by faults extending for as long as several 100 km, the seismic waves are usually simulated by point source summation. In this paper, we attempt to follow a different route, i.e., directly calculate the excitation of each mode, and use normal-mode sum- mation to obtain the seismogram. Furthermore, we assume the finite source to be a ＂line source＂ and numerically calculate the transverse component of synthetic seismo- grams for vertical strike-slip faults. Finally, we analyze the features in the Love waves excited by finite faults.

浪漫的倒影——贝尔格《露露之歌》的结构与音高组织逻辑研究

奥地利作曲家阿尔班·贝尔格于1933年创作的《露露之歌》(Lied der Lulu)源自其同名歌剧《露露》(Lulu),主要运用了歌剧中的基本序列和露露序列作为音高组织。文章通过对其结构及音高组织逻辑的分析,进一步研究作曲家将理性的作曲技术层面与感性的音乐情感表达相结合、在艺术层面上得到平衡与升华的方式。

Reduction of electric field strength by two species of trees under power transmission lines

Electrical pollution is a worldwide concern,because it is potentially harmful to human health.Trees not only play a significant role in moderating the climate,but also can be used as shields against electrical pollution.Shielding effects on the electric field strength under transmission lines by two tree species,Populus alba and Larix gmelinii,were examined in this study.The electrical resistivity at different heights of trees was measured using a PiCUS sonic tomograph,which can image the electrical impedance for trees.The electric field strength around the trees was measured with an elf field strength measurement system,HI-3604,and combined with tree resistivity to develop a model for calculating the electric field intensity around trees using the finite element method.In addition,the feasibility of the finite element method was confirmed by comparing the calculated results and experimental data.The results showed that the trees did reduce the electric field strength.The electric field intensity was reduced by 95.6%,and P.alba was better than L.gmelinii at shielding.

河南内乡宝天曼国家级自然保护区豹猫及其潜在猎物之间日活动节律的季节性

日活动节律是动物应对食物可利用性、天敌捕食风险和环境条件等变化的适应性特征。阐明捕食者与猎物之间的日活动节律以及相关影响因素,对于理解不同物种的生存策略、指导保护对策至关重要。然而,由于采样方法的限制和人类干扰下的快速环境变化,人们对许多野生动物日活动节律的了解并不全面,甚至与实际情况存在偏差。以往认为夜行性的豹猫(Prionailurusbengalensis)被发现有一定程度的日间活动,并增加晨昏活动,这说明有必要深入调查豹猫等野生动物的昼夜节律为何存在这些变化。本研究在河南内乡宝天曼国家级自然保护区通过红外相机技术对豹猫及其潜在猎物进行调查,基于核密度函数比较分析了豹猫与其潜在猎物在冷、暖季节的日活动节律。2016年全年设置了55个红外相机位点,累计14,972个相机工作日,获得豹猫及其潜在猎物的独立有效照片1,343张。结果显示,该保护区内豹猫、蒙古兔(Lepus tolai)和鼠类以夜间活动为主,其中豹猫有明显的晨昏活动高峰,而赤腹松鼠(Callosciurus erythraeus)、岩松鼠(Sciurotamias davidianus)、红腹锦鸡(Chrysolophus pictus)和勺鸡(Pucrasia macrolopha)均在昼间活动。活动重叠度分析结果显示,豹猫与夜行性的蒙古兔和鼠类在冷季和暖季均有较高重叠度(Δ≥0.50),但与其他猎物之间的重叠度均相对较低(Δ≤0.40)。本研究显示豹猫及其猎物的昼夜节律既有保守性,也具有一定的季节可塑性,可能受到季节性猎物分布和环境变化的影响。因此,需要加强调查研究来充分认识不同物种日活动节律的季节性变化规律及其驱动因素。