Relative effectiveness of topical, filter paper and grain applications of deltamethrin, and associated behaviour of Rhyzopertha dominica (F.) strains

The susceptibility of stored grain pests to insecticides may be assessed by different types of bioassay application methods such as topical, impregnated filter papers and grain treatments. Pests may behave differently when in contact with pesticides and these changes in behaviour may contribute to their tolerance of pesticide. To compare the three application methods and determine how Rhyzopertha dominica (F.) behaved on contaminated filter papers and treated grain, experiments were carried out on four strains of this species. The strains were of known susceptibility to deltamethrin; three were from Brazil (BR4, BR6 and BR7) and one from the United Kingdom (UK1). BR4 and UK1 were susceptible strains, and BR6 and BR7 were resistant strains. Behavioural responses of the pest to deltamethrin were compared between resistant and susceptible strains by measuring the walking response of individuals on deltamethrin impregnated filter papers and the repellent effect of treated wheat grain. The body weights of strains were compared. The results showed resistance ratios of 21, 175 and 17 times between the most susceptible and the most resistant strains, following topical, filter paper and grain applications, respectively. The most resistant strain walked less on contaminated filter papers while the most susceptible strain did not change its walking pattern. Deltamethrin showed no repellent effect, neither on impregnated filter papers or in treated wheat grain. The body weights differed among the strains but were not associated with the level of tolerance to deltamethrin.     

Perception of Visual Speed While Moving.

During self-motion, the world normally appears stationary. In part, this may be due to reductions in visual motion signals during self-motion. In 8 experiments, the authors used magnitude estimation to characterize changes in visual speed perception as a result of biomechanical self-motion alone (treadmill walking), physical translation alone (passive transport), and both biomechanical self-motion and physical translation together (walking). Their results show that each factor alone produces subtractive reductions in visual speed but that subtraction is greatest with both factors together, approximating the sum of the 2 separately. The similarity of results for biomechanical and passive self-motion support H. B. Barlow's (1990) inhibition theory of sensory correlation as a mechanism for implementing H. Wallach's (1987) compensation for self-motion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

仿生机器蟹机构设计及结构参数优化

通过对原型生物体的结构简化 ,确定了仿生机器蟹步行机构的结构框架 ,引入了变向性、灵活性的概念 ,提出了以变向角、灵活度作为评价躯体灵活性的综合指标 ,在仿真环境下测试了仿生机器蟹结构参数对其变向性、灵活性的影响 ,并据此得到了优化的仿生机器蟹结构参数     

Effects of toe stiffness on ankle kinetics in a robotic transtibial prosthesis during level-ground walking

Robotic transtibial prostheses are gaining popularity, as they significantly improve amputees’ locomotion. Existing studies mainly concentrate on the importance of ankle joints in these prostheses. However, there are few studies that focus on the effects of prosthetic toe joints. Different from human feet, most prosthetic feet are single-segment structures without toe joints. In order to develop more human-like prostheses with ankle and toe joints, it is of great importance to investigate the effects of toe stiffness on ankle kinetics, as it contributes to the design and control optimizations. In this paper, we analyze the effects of toe stiffness on ankle kinetics in a robotic transtibial prosthesis we have built recently. Dynamic models of the prosthesis’ ankle and toe joints are built. The imposed plantar pressures and objective joint angles of these models are obtained from locomotion experiments on able-bodied subjects. Simulation results indicate when the toe joint is fixed, the ankle energy consumption in one gait cycle is almost 1.2 times of that when the toe joint is driven to track the able-bodied toe motion. Experiments of the prosthesis prototype are carried out on an amputee subject with a transtibial amputation. The results show that compared with the fixed toe joint either the active toe joint or the passive toe joint can reduce the ankle output moment and power consumption. This means adding a toe joint to the foot can reduce the designing requirements of the ankle joint. In addition, the active toe joint can help the prosthesis perform more human-like behaviors compared with the passive toe joint. On the other hand, the passive toe joint can simplify the prosthesis structures and reduce the total weight compared with the active toe joint.     

双蓄热步进梁式加热炉在承钢棒线厂的应用

简单介绍了承钢提钒钢轧三厂三棒生产线加热炉大修改造的基本情况,从加热炉改造的目的,以及改造后的加热炉使用效果来说明加热炉改造非常成功。     

基于运动精确度的步行机器人轨迹跟踪中控制节点的契比雪夫插值研究

研究在轨迹跟踪中以契比雪夫函数确定运行轨迹的控制节点,对多足步行机器人期望的质心轨迹逼近,以提高机器人的运动精度问题;在对相关理论进行描述的基础上,以机器人ZQROT-I运行给定二次曲线轨迹为例,利用ADAMS,对该机器人在运行过程中采用相同轨迹函数及不同控制节点对机器人运动精度的影响进行了比较分析。分析结果可以作为机器人优化控制方案的依据。     

强制循环汽化冷却在步进梁式加热炉中的应用

简要介绍了步进梁式加热炉炉内水梁结构布置,在此基础上论述了步进梁式加热炉强制循环汽化冷却系统的基本原理及其组成,并给出了强制循环汽化冷却在某钢厂的成功应用范例及其应用效果。     

步进炉内方坯间综合角系数计算的研究

从步进炉内方坯间综合系数计算的实际问题出发，推导了非透明介质有限封闭区域综合角系数的精确计算公式，并以Ｔｕｃｋｅｒ的精确数值计算结果为依据，比较了面间透过率的五种近似算法的计算精度，最终获得了可用于实际计算的较为准确的综合角系数近计算方法。     

采煤机主要部件的故障分析及改进方案

探讨了采煤机主要部件的几种常见故障,对每一故障的引发原因进行了细致分析,并结合生产实践提出了一些有针对性的改进方案,为采煤机制造厂家和煤矿生产企业提供了设计改进和使用维修参考。     

接头连接PCR步行法鉴定转基因烟草

应用接头连接PCR步行法,建立了分子水平鉴定不同转基因事件的方法和体系;并利用不同转基因事件外源基因与植物基因组DNA整合位点处核酸序列的差异,设计了不同转基因烟草事件的标签引物,成功地对几个转TMV-CP材料进行了鉴定。