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Modified nanocellulose fibers (MCNFs) were added to the high energy nitroamine gun propellant to explore its influence on the mechanical and energy properties of the gun propellant. In this paper, nanocellulose fibers (CNFs) and MCNFs with a content of 1% were added in the high energy nitroamine gun propellant formula. The mechanical properties, fracture surface structure and energy performance are characterized by the impact strength test equipment, universal material experiment machine, scanning electron microscope (SEM) and closed vessel test. The results show that in terms of low-temperature tensile properties, low-temperature compression properties, and low-temperature impact resistance, the MCNFs-containing propellant samples increased by 2.97%, 1.94%, and 20.4%, respectively, compared with the CNFs-containing propellant samples. The difference in energy properties between the two is not significant. Compared with CNFs, MCNFs can better combine with nitrocellulose matrix in microstructure.

A new porous metal-organic framework, [Pb5(OAc)7(nIm)3]n (1), has been successfully synthesized by employing 2-nitroimidazole ligand and Pb2+ ion. 1 contains novel the ribbon-shaped Pb-O SBU and reveals a 2D porous framework with a 1D tubular channel. Due to the existence of the electronegative O atom of nitro group and Lewis acid metal ion in the channel, 1 shows moderate CO2 adsorption uptake of 25.8 cm3 cm− 1 at 298 K and 760 mmHg, and adsorption sites are also confirmed by GCMC simulations. Moreover, the electronic structures and luminescence properties of 1 was investigated. This work displays an effective approach to enrich multifunctional porous Pb-MOFs.

Spinel Li4Ti5O12 (LTO) doped with Mg2+ was synthesized by solid-phase reaction method. The Mg2+ doping quantity was 3%, 6%, 9%, and 12%, respectively. The structure and electrochemical performance of the prepared LTO composites were investigated by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and galvanostatic charge-discharge tests. It was found that the doped Mg ion did not change the structure of Li4Ti5O12, and it was evenly distributed around Li4Ti5O12. When Mg2+ doping quantity increased from 3% to 12%, the internal resistance and charge transfer resistance of the composite both decreased. The first discharge specific capacity of 6%-Mg2+ doped LTO composite was 168 mAh/g, which was close to the theoretical capacity of pure lithium titanate (175 mAh/g), and the capacity retention rate was 98% after 100 cycles.

Almost all the fields use tree modeling in society. But it is difficult to find an efficient tree modeling method because its own complexity and wind, rain acting on tree. This paper constructs tree static modeling with expanding 2.5D modeling method and collision principle. The object suffers wind power that the force calculated by momentum theorem. And then compare the value of rupture limit to Young modulus. It is determined object to fracture or sway. Then it constructs tree dynamic modeling in the nature.

To test the feasibility of proposed double-loop force loading control structure for the integrated testing system for high-speed train end relationship, it established the co-dynamics model of Stewart parallel manipulator and transfixion and developed the PID force controller. The sine force tracking simulation test was carried out in Simulink environment. The results show that, whether the input is in single dof or in 6 dofs, the output can meet the demand of amplitude attenuation and phase lag . This proved that this system has a good performance in force loading and the proposed control structure is feasible for the force loading test of transfixion.

Manipulability indexes have been extensively used as objective functions or constraints in the optimal design of robots, especially for the robots with pure active joints and the end-effectors only involving positioning or orientation. The moving platform of Gough-Stewart platform can involve both positioning and orientation, which leads to the conventional Jacobian matrix with entries bearing disparate physical units, then the established manipulability index based on the conventional Jacobian matrix has no physical meaning and is variable under a change of units. Based on a dimensionless Jacobian matrix, this paper established a new manipulability index, which has physical meaning and is invariant under a change of units. In order to design a good performance motion simulator, the extreme values of the new and old manipulability indexes of 2 commercial flight simulators in their reachable workspaces were found by random search method, respectively. From the results, the extreme values of the new manipulability index are in regularity, and can be used as references in the optimal design of the Gough-Stewart platform as motion simulator.

To test the motion characteristic of parts between two train cabinets, an integrated testing system based on the Stewart parallel manipulator for train end relationship has been built in the National Engineering Laboratory for System Integration of High-speed Train. It analyzed the kinematics of this system and carried out series of experimental test. The results of static positioning test and dynamic tracking test show that the testing system has a good characteristic of motion simulation. This is the first time that the Stewart parallel manipulator is applied in high-speed train field.

Steady operation was one of the main objectives of wind turbine controlling. Online monitoring and fault diagnosis system had been installed on the wind turbine, the characters of system natural frequency were obtained by comparing collecting datum in site with theory analysis result. Wind turbine rotation speed should avoid [8.4r/min,10r/min] base on the characters to guarantee no resonance and avoid severe vibration. Such realizes wind turbine steady operation.

To discuss the treatment of the windblow hand deformity.We treat 18 patients with operations step by step. First phase: to improve the thumb function; Second phase: shift the flexor digitorum superficialis of the middle and little finger to improve the ulnar drift of the digits; Third phase : to solve the flection deformity of the palm and digits.We follow the patients for 6 - 72 months, only lost 3.11 of 15 patients have the thumb function recovered. 9 patients had their ulnar drift of the digits corrected, 2 patients partly corrected, 4 have relapse. 5 among the 15 patients were offered second operation, to have the ulnar arthrosis bursa contracted, using abduction splint, after rehabilitation 4 patients have the deformity corrected, 1 has partly corrected.Operation step by step is better for the complex windblow hand deformity, solve one major problem each time,and systemic rehabilitation therapy is needed for satisfied curative effect.