This article describes the design and synthesis of quinoxaline-based semiconducting polymer dots (Pdots) that exhibit near-infrared fluorescence, ultrahigh brightness, large Stokes shifts, and excellent cellular targeting capability. We also introduced fluorine atoms and long alkyl chains into polymer backbones and systematically investigated their effect on the fluorescence quantum yields of Pdots. These new series of quinoxaline-based Pdots have a fluorescence quantum yield as high as 47% with a Stokes shift larger than 150 nm. Single-particle analysis reveals that the average per-particle brightness of the Pdots is at least 6 times higher than that of the commercially available quantum dots. We further demonstrated the use of this new class of quinoxaline-based Pdots for effective and specific cellular and subcellular labeling without any noticeable nonspecific binding. Moreover, the cytotoxicity of Pdots were evaluated on HeLa cells and zebrafish embryos to demonstrate their great biocompatibility. By taking advantage of their extreme brightness and minimal cytotoxicity, we performed, for the first time, in vivo microangiography imaging on living zebrafish embryos using Pdots. These quinoxaline-based NIR-fluorescent Pdots are anticipated to find broad use in a variety of in vitro and in vivo biological research.

To solve the inverse kinematics problem of a robot manipulator without closed form solutions, one-dimensional iterative method is very useful. However, for a 5-DOF robot manipulator, because of the uncontrolable and uncertain orientation vectors, it's difficult to analytically express all joint variables by one of them, therefore one-dimensional iterative method can not be directedly used. By adding an appropriate virtual joint to it, a 5-DOF manipulator can be changed into a 6-DOF one so that the uncertain orientation vectors can be pre-given, and the difficulty is solved. To illustrate this virtual joint method a 5-DOF serial robot manipulator with prismatic arm joint and offset wrist is discussed in this paper as an example.

Electromechanical control CVT (EM-CVT) is a new type of continuously variable transmission, and its ratio quality is an important parameter validated the performance of vehicle. In order to study the dynamical coupling technology between EM-CVT and engine under the running state of vehicle, the special character of two working models is obtained by engine experiment; according to the principle of the EM-CVT, the relation between vehicle speed and ration is theoretically analyzed. Based on the basic theory of PID control, the improved PID control algorithm is proposed for the speed ratio control of the EM-CVT, and experimental verification is made. The experimental results show that there is a significant effect on the system with this algorithm.

The laying pipe manipulator is used to lay concrete pipe, and it solves the question of safety, quality, and efficiency in the pipe laying construction site, and the critical question of locating system is studied. The work principle and mathematical model of locating system were established, and the experiment of locating system was done. According to the test result, the work principle and mathematical model of locating system had turned out to be well adapted for requirement. The locating system of laying pipe manipulator can be applied to product development. The mathematical model of locating system supplies the basic control theory for the manipulator to lay and joint concrete pipe automatically.

This paper presents a tolerance modeling approach based on robot kinematics theory within CAD/CAM system. Based on the differential kinematics theories, each feature of characteristics including size tolerance and geometrical tolerance was established as a corresponding small displacement torsor. In order to express the relation between the small displacement of all functional features and the functional requirement, the final expression was represented to establish the projection of analysis of the tolerance chain. A mathematical expression was obtained by the mean instead of single points, and the constraints can be represented by interval using the standard deviation, not limit deviations. After having identified the unit components and the functional requirement from the tolerance chain, we obtained the percentage contribution of each unit feature to the functional requirement. A percentage contribution can help designer to decide which tolerance is tighten or loosen. The application of the tolerance analysis approach in a simple three-dimensional sample was also discussed in this paper.