森林水文效应的综合分析

引用森林水文实验站和国家水文基本站网中的森林流域和非森林流域的实测资料,进行同步期的对比分析.对于试验小流域或径流场,总结出林冠截留、树干径流和林地拦蓄的一些统计结果,并归纳得到可供利用的计算公式.对于大面积森林流域,主要从基本水文站网中,森林覆盖率明显不同而其它自然地理条件类似的测站进行对比分析,当干旱指数小于1.2的地区,森林使年径流增加,当干旱指数大于1.2的地区,森林使年径流减少.     

Optical Trajectories and the Informational Basis of Fly Ball Catching.

D. M. Shaffer and M. K. McBeath (see record 2002-02027-006) plotted the optical trajectories of uncatchable fly balls and concluded that linear optical trajectory is the informational basis of the actions taken to catch these balls. P. McLeod, N. Reed, and Z. Dienes (see record 2002-11140-016) replotted these trajectories in terms of changes in the tangent of optical angle over time and concluded that optical acceleration is the informational basis of fielder actions. Neither of these conclusions is warranted, however, because the optical trajectories of even uncatchable balls confound the information that is the basis of fielder action with the effects of those same actions on these trajectories. To determine the informational basis of fielder action, it is necessary to do the control-theory-based Test for the Controlled Variable, in which the informational basis of catching is found by looking for features of optical trajectories that are protected from experimentally or naturally applied disturbances. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

济钢1#高炉热风炉自动换炉系统

在高炉大修改造工程中,将原有热风炉手动换炉系统改造成为自动换炉电控系统,通过PLC采集温度、压力等信号,控制各阀门的开关来实现自动换炉,并解决了温度控制自动换炉过程中,检测温度波动较大,不易控制的问题。此技术的应用,实现了换炉自动化,降低了工人的劳动强度,可提高燃烧温度10℃,每年可节约焦碳860t。     

API函数截获关键技术研究

文中介绍了API函数截获技术的原理，重点讨论了所涉及到的若干关键技术，剖析了PE文件的引入函数表格式，给出了利用钩子打破进程边界的方法，并对截获过程中存在的不稳定、效率低等问题提出了自己的解决方法。应用文中所介绍的方法，作者在某矿务系统的软件改造项目中成功地实现了基于API截获技术的实时数据采集，完成了对已有软件系统的功能升级。实践证明，API截获技术及其思想具有很强的实用性，可以解决一些常规的方法不能解决的问题，能很好地使用在诸如实时数据采集等场合。     

用中断拦截实现对步进伺服电机的变频控制

在数控机床的各类控制系统中 ,由加工工艺要求而需要步进伺服系统在不同的时刻输出不同的转速 ,并且根据步进电机的加减速特性 ,进入步进电机定子绕组的电平信号的频率变化要平滑。在此介绍用中断拦截的方式实现对步进伺服电机的变频控制。     

森林林冠对降雨量截留的实验分析

以实测资料为基础，分析了林冠对降雨量的截留量。     

Escape trajectories are deflected when fish larvae intercept their own C-start wake

Fish larvae may intercept their own wake during sharp turns, which might affect their escape performance. We analysed C-starts of larval zebrafish (Danio rerio, Hamilton, 1822) using a computational fluid dynamics approach that simulates free swimming (swimming trajectory is determined by fluid forces) by coupling hydrodynamics and body dynamics. The simulations show that fish may intercept their own wake when they turn by 100–180°. During stage 1 of a C-start, the fish generates a strong jet at the tail that is shed into the wake. During stage 2, the fish intercepts this wake. Counterfactual simulations showed that wake interception increased the lateral force on the fish and reduced the fish''s turning angle by more than 5°. Wake interception caused no significant acceleration tangential to the trajectory of the fish and did not affect total power output. While experimental and simulation evidence suggests that fish larvae can either undershoot or intercept but not overshoot their wake, our simulations show that larger fish might be able to avoid intercepting their wake by either under- or overshooting. As intercepting its own wake modifies the fish''s escape trajectory, fish should account for this effect when planning their escape route.     

跨高速铁路施工安全防护棚架设计

结合工程实例,对跨高速铁路施工防护棚架的设计和施工方案进行了研究,并对荷载、防护支架结构、防护支架拆除后钢管立柱的稳定性作了计算分析,证明了该防护棚架设计的合理性。     

Actualising (Overlooked) Material Capacities

An emphasis on material synthesis is not without its pitfalls and challenges. Here Branko Kolarevic , Professor and Chair in Integrated Design at the University of Calgary Faculty of Environmental Design, alerts us to the dangers of overlooking materials' shifting capacities, which are so often scale dependent, while also disregarding existing materials in favour of the new or novel. As the potential grows for material systems in buildings to become more adaptive and to harness automation, Kolarevic describes some exciting developments that are taking place in dynamic facade design, providing the much-heralded promise of an efficient use of ambient energy.