一款老人助力起身智能马桶研究

研究一款能在现有旧式马桶基础上,通过加装助力起身智能马桶盖,实现助力起身和智能冲洗的结合,简化操作动作,适应老人使用的设备。     

DYNAMIC ANALYSIS OF ASYMMETRIC FRAME-SHEAR WALL SYSTEM BY STAGE CONTINUITY METHOD

The lateral structures of frame-shear wall system are simplified into bending beams and shear beams which stiffness can vary in different stages along the building height. The three-dimension stiffness matrix and mass matrix are deduced, and the characteristic equation is established to calculate the tortuous free vibration of the asymmetric system. The method is simple and has satisfactory precision, and it is easily fulfilled in micro-computers.     

切割函数关于第二参数的分析性质

重新定义了平面曲线的切割函数,使用经典的微分几何方法,得到了平面曲线的切割函数对第二参数的连续性和可微性,即平面曲线的切割函数关于第二参数也是连续函数;光滑曲线拓广的切割函数对两个参数都是光滑的.     

极限函数与和函数的关系及其连续性

给出极限函数与和函数的定义．讨论了极限函数与和函数之间的关系，利用极限函数得到函数项级数收敛的一个必要条件，研究了极限函数与和函数的连续性，得到部分和函数列连续的一个充分条件．     

会说话的石头——从城市景观中的石头看法国南部城市发展逻辑

法国南部城市有着悠久的使用石头建造城市景观和建筑的历史,石头以其稳重而灵活的特性成为构成城市意向的骨架。本文描述了法国南部城市中,石头在传统和现代景观中的存在形式,并总结了现代法国人如何用石头延续城市历史的3种方式。从中可见法国城市发展过程中的连续性逻辑,以及法国人对待历史的谦虚态度。     

Lichen diversity in temperate montane forests is influenced by forest structure more than climate

Although the effect of forest management on lichens in temperate forests has been widely examined, little is known about the influence of management-related factors on their biodiversity relative to factors that cannot be altered by management. Here we determined whether forest structure or climate determines lichen diversity in the Bavarian Forest National Park in southeastern Germany, taking spatial variables into account. We investigated 517 single tree stems along 4 transects in 113 pre-stratified plots (8 m in diameter) in this montane forest. We grouped environmental variables into three sets: climate (macroclimate, non-manageable), forest structure (manageable), and space. The explanatory powers of these sets of variables for lichen diversity were compared using variance partitioning for the lichen community, species density, and threatened species density. The relationships of single characteristics of forest structure with lichen species diversity were analyzed using generalized linear models (GLM). Lichen diversity was better explained by stand structures than by climate. Spatial effects influenced the number of species per plot. Among the structural features, the availability of dead wood and sycamore maple as well as forest continuity were most important for the enhancement of lichen diversity. Open canopy structures affected the total diversity positively. Although the availability of large trees was not an influential factor in the GLM at the plot level, high diversity levels were generally associated with large stem diameters at the level of single stems. We provide recommendations for sustainable forest-management practices that aim at specifically enhancing lichen diversity in temperate areas experiencing low levels of air pollution.     

Promoting connectivity between priority freshwater sites for conservation in intermittent hydrological systems

1. Systematic conservation planning in freshwater ecosystems faces multiple challenges because of the dynamic nature of rivers and their multiple dimensions of connectivity. In intermittent hydrological systems connectivity is functional when water is available, allowing the exchange of aquatic individuals between isolated freshwater ecosystems. Integrating these isolated systems in their hydrological context is essential when identifying priority areas for conservation, in order to try to minimize the propagation of threats into target water bodies (management units) from the surrounding landscape.
2. Here, the use of a systematic planning approach is demonstrated to identify a set of priority management units to preserve freshwater biodiversity in an arid system of fragmented water bodies immersed in a landscape subject to a range of impacts.
3. Twenty-six water-dependent taxa from 59 mountain rock pools (gueltas) of three southern Mauritanian mountains were used as a case study. A conservation planning tool (marxan ) was used to find priority conservation areas to integrate intermittent hydrological systems in their hydrological context, promote connectivity, and minimize the downstream propagation of threats. Three types of connectivity were analysed: (i) no connectivity, (ii) connectivity between gueltas, and (iii) connectivity between gueltas and sub-catchments.
4. Considering different types of longitudinal connectivity affects the number and spatial allocation of the priority gueltas selected, and the conservation status of the gueltas and their upstream areas. Incorporating connections between gueltas and upstream locations in the modelling resulted in the selection of gueltas in areas with a low human footprint and in the increased connectivity of the solutions.
5. The results obtained revealed important locations for local biodiversity conservation, and the method presented can be used when assessing the propagation of potential waterborne threats into isolated management units. The framework developed allows connectivity to be addressed in conservation planning. It can be replicated in regions with similar isolated habitats that connect through intermittent hydrological systems and can also be applied to lateral and vertical hydrological connectivity.

     

城市广场发展中的隐喻演变研究

通过对广场历史发展的研究,分析了4个广场的案例,得出了隐喻的5个不同时期的演变:民主政治的隐喻、帝王君权的隐喻、宗教神权的隐喻、人文精神的隐喻、历史文脉的隐喻.认为历史延续性和社会适应性是城市广场隐喻演变的两大特性.     

一类时滞系统的解半群的范数连续性

讨论了时滞线性系统的解半群的范数连续性,其方法是:在一个特定的相空间中,把时滞系统转化为无时滞的抽象柯西问题,再运用半群理论解决解半群的范数连续性.     

新疆北部地区春夏季干旱的区域性和持续性特征

基于1961-2007年36站的逐日降水资料,分析新疆北部地区春、夏季干旱的区域性和持续性特征。结果表明：新疆北部春、夏季干旱发生较为频繁,尤其在北疆西北部地区,春旱平均3 a一遇,夏旱为4~5 a一遇。季节间的连旱概率较低,不足10%,主要以月际间的连旱为主,其中2个月的持续干旱次数占干旱总次数的20%左右。进一步的分析表明,春夏之交的5~6月,是2个月连续干旱发生次数相对频繁的时期,北疆西北部地区此类连续干旱事件最多。伊犁河谷、北天山地区和北疆北部春旱较夏旱频繁,春旱以北疆北部发生最多;夏旱3个区域发生频次相似,但北天山地区大旱发生频数较高。3个区域的春、夏季干旱程度均呈减弱趋势,春旱在20世纪90年代中后期、夏旱在80年代中后期处在一个较低的发生期。