Responses of root growth of Alhagi sparsifolia Shap. (Fabaceae) to different simulated groundwater depths in the southern fringe of the Taklimakan Desert, China

Alhagi sparsifolia Shap. （Fabaceae） is a spiny, perennial herb. The species grows in the salinized, arid regions in North China. This study investigated the response characteristics of the root growth and the dis- tribution of one-year-old A. sparsifolia seedlings to different groundwater depths in controlled plots. The eco- logical adaptability of the root systems of A. sparsifolia seedlings was examined using the artificial digging method. Results showed that： （1） A. sparsifolia seedlings adapted to an increase in groundwater depth mainly through increasing the penetration depth and growth rate of vertical roots. The vertical roots grew rapidly when soil moisture content reached 3%-9%, but slowly when soil moisture content was 13%-20%. The vertical roots stopped growing when soil moisture content reached 30% （the critical soil moisture point）. （2） The morphological plasticity of roots is an important strategy used by A. sparsifolia seedlings to obtain water and adapt to dry soil conditions. When the groundwater table was shallow, horizontal roots quickly expanded and tillering increased in order to compete for light resources, whereas when the groundwater table was deeper, vertical roots developed quickly to exploit space in the deeper soil layers. （3） The decrease in groundwater depth was probably respon- sible for the root distribution in the shallow soil layers. Root biomass and surface area both decreased with soil depth. One strategy of A. sparsifolia seedlings in dealing with the increase in groundwater depth is to increase root biomass in the deep soil layers. The relationship between the root growth/distribution of A. sparsifolia and the depth of groundwater table can be used as guidance for harvesting A. sparsifolia biomass and managing water resources for forage grasses. It is also of ecological significance as it reveals how desert plants adapt to arid environments.

Dark-field detection method of shallow scratches on the super-smooth optical surface based on the technology of adaptive smoothing and morphological differencing

In recent years, modern optical processing technologies, such as single point diamond turning, ion beam etching, and magneto-theological finishing, arc getting break- throughs. Machining precisions of super-smooth optics have also been significantly improved. However, with increasing demands for the optical surface quality,

Bio-inspired interactive kinetic façade:Using dynamic transitory-sensitive area to improve multiple occupants’visual comfort

The architectural form of the façade determines its identity as well as interactions with micro-climate forces of the ambient environment,such as solar radiation.The dynamic nature of daylight and occupants’positions can cause some issues such as heat gains and visual discomfort,which need to be controlled in real-time operation.Improving daylight performance and preventing visual discomfort for multiple occupants simultaneously is challenging.However,integrating the biomimicry principles of morphological adaptation with dynamic,complex fenestration,and human-in-loop systems can lead us to find an optimal solution.This research builds on relevant literature study,biomimicry morphological approaches,and parametric simulations,to develop a bio-inspired interactive kinetic façade for improving multiple occupants’visual comfort simultaneously,inspired by plant’s stomata movement and behavior principles.Learning from the transitory stage and hunting new position of stomata’s patchy patterns,leads us to identify the dynamic transitory-sensitive area of attraction point on the façade that is triggered by the dynamic sun-timing position and multiple occupants.The annual climate-based metrics and luminance-based metric simulation results of 810 bioinspired interactive kinetic façade alternatives prove that the elastic-deformable-complexkinetic form triggered by the dynamic transitory-sensitive area can improve the visual comfort of multiple occupants simultaneously.In particular,the bio-inspired interactive kinetic façade with grid division 8x1 displays extraordinary daylight performance for south direction that prevents visual discomfort by keeping cases in the imperceptible range while providing an adequate average Spatial Daylight Autonomy of 60.5%,Useful Daylight illuminance of 90.47%,and Exceed Useful Daylight illuminance of 2.94%.