The development of Nemurella pictetii Klapálek (Plecoptera: Nemouridae) in two springstreams in central Europe

From April 1997 to June 1998 Nemurella pictetii populations were regularly sampled in two springstreams at 220 and 850 m a.s.l., respectively, in Hesse (Germany), at approximately 51°N. Random samples of larvae were taken at three week intervals during the vegetation period, and once a month during winter. Sex, instar, body length, head capsule width and wing pad length of all larvae were recorded. Temperatures were recorded every hour, temporal patterns of temperature agreed closely between sites. Mean winter lows were 3.9 °C at both sites, the mean summer high was 11.9 °C at the lower site, as opposed to 9.6 °C at the mountain site.At both sites, adult emergence started in May. At the mountain site, recruitment started in late July and continued into autumn. There was cohort splitting in the young generation. Some individuals grew rapidly until October–November, but last instar larvae first appeared in March the next year. 1600 degree-days above 0 °C were accumulated during complete development. At the lower site, recruitment began in early July, and cohort splitting also occurred. Fast growing summer recruits emerged as adults in late August, having accumulated only 700 degree-days (above 0 °C). Their offspring hatched in November-December and emerged the next spring, having accumulated also only 700 degree-days. However, only part of the population was bivoltine. Many of the summer recruits grew more slowly and accumulated close to 1900 degree days until they emerged the next spring, together with the offspring of their own fast-growing siblings. Dependence of growth rate on temperature could not be estimated and appears to vary with daylength. For example, 3–6 °C support growth and development provided daylength exceeds 10 hrs of light, or is rising.At both sites and in all cohorts individuals emerging earliest were larger than later emerging ones. The size decline is significantly correlated with number of days after the winter solstice. For the first time it is shown that the decline does not occur shortly before adult emergence but actually takes place several instars before the last. Size differences are then carried on, and amplified, during subsequent molts, until adulthood. The literature presently relates seasonal size declines of insects to high or rising temperatures experienced by larvae approaching adulthood. Our data show that, at least in Nemurella, this explanation fails. On average, females were distinctly larger than males. Differences in mean last instar size were noticed also between sites and years. They remain presently unexplained. The mean sex ratio in both populations was close to 1:1.     

A rooftop tuned mass damper frame

This article documents the analytical study and feasibility of placing a tuned mass damper in the form of a limber rooftop moment frame atop relatively stiff structures to reduce seismic acceleration response. Six existing structures were analytically studied using a suite of time history and response spectra records. The analyses indicate that adding mass in conjunction with a limber frame results in an increase in the fundamental period of each structure. The fundamental period increase generally results in a decrease in seismic acceleration response for the same time history and response spectra records. Owing to the limber nature of the rooftop frames, non‐linear analysis methods were required to evaluate the stability of the rooftop tuned mass damper frame. The results indicate the addition of a rooftop tuned mass damper frame reduces the seismic acceleration response for most cases although acceleration response can increase if the rooftop frame is not tuned to accommodate the specific structure's dynamic behaviour and localized soil conditions. Appropriate design of the rooftop tuned mass damper frame can result in decreased seismic acceleration response. This translates to safer structures if used as a retrofit measure or a more economical design if used for new construction. Copyright © 2003 John Wiley & Sons, Ltd.     

对测绘个别名词术语英文对应词的商讨

提出了对测绘辞书中个别汉语名词术语所附英文词的修改意见或建议，与测绘界同行商讨。     

TEM study of a special grain boundary in a synthetic K-feldspar bicrystal: Manebach Twin

 A monoclinic KAlSi₃O₈ feldspar Manebach twin boundary was synthesized by diffusion bonding and examined using high-resolution transmission electron microscopy. The sharp (001) twin boundary is straight and free of strain. The boundary width is smaller than d₀₀₁. There is no rigid body shift observed at the twin boundary, and the feldspar structure is arranged symmetrically across (001). The twin boundary structure consists of bridged tetrahedral crankshafts, which are characteristic of the feldspar lattice. The grain boundary structure is in good agreement with the geometrical model of Taylor et al. (1934). The grain boundary composition of K_1/2H_1/2AlSi₃O₈ differs from their model. Received: 13 February 2002 / Accepted: 24 December 2002 Acknowledgements We thank M. Rühle, S. Hutt, J. Mayer, A. Strecker and U. Salzberger at MPI, Stuttgart, for their support and valuable advice in preparing TEM sections of bicrystals.     

GPS折射角资料的变分同化试验

越来越多的新型观测资料为数值天气预报水平的进一步提高提供了许多新的机会。在各种新型的观测资料中,GPS(全球定位卫星系统)折射角资料无疑是非常重要的。GPS折射角资料具有分辨率高、全天候探测、覆盖全球等优点,实现对GPS折射角资料的变分同化,将具有非常重要的意义。文中介绍了如何获得及同化GPS折射角资料的原理。对GPS折射角资料的变分同化可以分为两种:间接同化和直接同化,文中对这两种方法都作了具体介绍。在变分同化的最小化过程中,计算效率无疑是最重要的,而优化步长的计算又直接关系到算法效率的成败。根据最小化算法的特点,通过数学推导,得出一种适合于各种最小化算法的计算优化步长的自适应方法。最后,还利用1995年10月11日的GPS折射角资料进行了数值试验,结果表明了变分同化方法和计算优化步长方法的有效性。     

地震勘探中的炸药震源药量理论与实验分析

炸药由于具有良好的脉冲特性及高能量的特点而作为地震勘探中的主要震源，就炸药本身来说，在地震勘探中药量、井深等参数的选取对激发能量和激发频率有很大的影响。为此，本文运用炸药爆炸理论，从炸药作功角度来加以论述，并通过理论和实验分析得出选取一个最佳的药量和井深激发，既能提高炸药作功能力，又能增强激发能量，从而激发强能量的高频震源子波，达到指导野外地震采集和节约经济成本的目的。     

大气气溶胶光学厚度的宽带消光遥感方法及其应用

该文发展了遥感气溶胶光学厚度的一个宽带消光遥感方法 ,它应用地面上太阳直射表探测的宽波段太阳直射信息反演 0 75 μm大气柱光学厚度。这方法的主要误差因子是气溶胶谱的不确定性。数值试验表明 ,气溶胶谱分布的误差所引起光学厚度解的误差一般小于 5 %。 1995年 1— 10月进行的 12 6 7组对比实验表明 ,由本方法探测的气溶胶光学厚度与光度计探测的气溶胶光学厚度的标准差为 10 5 % ,两者平均结果的偏差只有 0 7%。该文还应用这个方法 ,从气象台站辐射观测资料反演得到北京、沈阳等 10个地方 1980— 1994年间晴天气溶胶光学厚度资料 ,并分析其变化规律     

丽江7.0级地震前地震分形异常

本提供了丽江７．０级地震前滇西北地震活动空间容量维、关联维、信息熵十分显的异常图像；这些异常是在大震孕震区形成、应变释放加速阶段之后出现的，恰好揭示了源区、近源区大释放前的非线性变化过程。这与１９６５年以来云南及邻区８组大震前地震分形研究的结论完全一致；进一步说明地震活动分形异常对地震孕育的短临阶段具有重要的指示意义。     

可控消能减震原理及结构分析

本文介绍一种新的减震结构体系及其分析方法。这种结构体系的减震系统由控制装置及耗能装置组成，控制装置根据结构反馈的相关信号，在回头点处启动耗能装置，耗散大量地震能量，属于半主动控制范畴。试验及理论分析表明，这种结构体系的减震效果良好，能够将结构的地震位移反应降低５０％以上。本文介绍了这种结构体系的减震工作原理、数学模型、理论分析方法及算例，并给出了相应的结论。     

SHOULD BESTOW MORE PHYSICAL CONNOTATION ON GRAIN SIZE PARAMETER

1.INTRODUCnONSAn~sizeplaysanimpo~roleinmanyfields,SUChasinndmeDt-laden~ordebrisflow.TheStateofsedimentmovementwhateVertheyaresugunded.jUInpingorbed-loading,isoftencloselyrelatedtOtheirSizes.Thebodyor~forcesbornacaglainareOftendiredproponionedtotheabcorSq~sizeofthisgrain.Thereforesedimentsizeisanimpohalltindextoesedimentcharacteristics.Besides,depositsizeanditsdistributionimplysome~infonnationdepositingfonnationenvironmentandcauseing~hyandgeqlogy.Ina~on.thesizeanditsdistributionareeac…