Time filter

Source Type

Peng X.-L.,Northwestern Polytechnical University | Fang Z.-D.,Northwestern Polytechnical University | Su J.-Z.,Northwestern Polytechnical University | Pei S.-S.,China North Industries Group Corporation
Hangkong Dongli Xuebao/Journal of Aerospace Power | Year: 2012

A method of tooth grinding for face gear machining by using grinding disk was proposed with the purpose to manufacture hardened face gear with high precision and obtain parabolic transmission errors and increase transmission stability. The generation theory and grinding disk motion of face gear abraded by grinding disk were analyzed, the surface equation of grinding disk was deduced according to the generation theory, and the double crowned tooth surface equation of face gear was derived based on using grinding disk with mismatch involute and modified movement of grinding disk. The model of tooth contact analysis of double crowned face gear meshing with traditional involute pinion was established. Instances of tooth surface calculation and tooth contact analysis indicate that the method of gear grinding applied to manufacture double crowned face gear through grinding disk is feasible, parabolic transmission errors of face gear can be obtained, edge contact is avoided and is enhanced the stability of transmission. Source

Wang J.-X.,Beijing Institute of Technology | Lin D.-F.,Beijing Institute of Technology | Qi Z.-K.,Beijing Institute of Technology | Cheng Z.-X.,China North Industries Group Corporation
Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology | Year: 2013

For issues of the disturbance rejection rate parasitical loop (DRRPL) of strapdown phased array radar seeker, the reasons for the problem were discussed. The normalized model of DRRPL was established, and the stability and the frequency response of DRRPL were analyzed. The effect of DRRPL on PN guidance system was studied with the method of adjoints. The results demonstrate that the imperfect decoupling and the error of angle measure are main reasons for the above problem of DRRPL. Compared with the feedback, the parasitical loop with the feedforward is more sensitive to disturbance rejection rate, and the open-loop crossover frequency gets lower when DRRPL is marginally stable. Important parameters and miss distance (MD) of PNG will be affected seriously by DRRPL. Source

Bao N.,Shandong University | Li Y.,Shandong University | Wei Z.,China North Industries Group Corporation | Yin G.,Shandong University | Niu J.,Shandong University
Journal of Physical Chemistry C | Year: 2011

In this Article, the surface characteristics of acid-modified continuous TiO2 fibers, the adsorption of dyes, and the photocatalytic degradation of dye pollutants under UV and visible light irradiation were investigated. After HF extraction of silicon, a hierarchical mesoporous structure is produced. The ?OH groups located on the surface were more resistant to exchange with F? because of the inductive effect on surface Ti4+ centers originating from adjoining electronegative F? ions. After protonation of the HF-modified fibers by HNO3 treatment, the photodegradation percentage of X-3B on the TiO2 fibers reached 98% in 45 min under visible light irradiation, and the first-order rate constant increased by a factor of 163.4. The high visible light activity was mainly attributed to a synergetic effect of the hierarchical mesoporous structure and the strong adsorption of X-3B upon the protonated surface. The adsorption isotherms showed that the adsorption of X-3B on acid-modified TiO2 followed the Langmuir model with a maximum adsorption capacity of 19.03 mg/g, 6-fold higher than the unmodified TiO2. The nature of the X-3B sorption was spontaneous and thermodynamically favorable. The sorption kinetics was best described by the pseudo-second-order model. © 2011 American Chemical Society. Source

Wang D.-Y.,China North Industries Group Corporation | Wen W.-D.,Nanjing University of Aeronautics and Astronautics
Hangkong Dongli Xuebao/Journal of Aerospace Power | Year: 2013

A series of quasi-static tension experiments and constant amplitude tension-tension fatigue experiments for researching the multilevel fatigue behavior under real cyclic loading were performed on single bolted joints in laminates with the ratio of the width of the laminate to the diameter of the central hole being 3 and the ratio of the distance between the central hole and the end of joint to the diameter of the central hole being 3. Real damage types and failure rules of single bolted joints in laminates were also discussed to provide the basis of stress level selecting of multilevel fatigue experiments. Finally, an experimental program of researching fatigue behavior under two-level fatigue for low-to-high and high-to-low loading sequence was conducted. Fatigue damage index was calculated and analyzed by using the classical linear progressive damage method of Miner rule. The results show that the fatigue damage index is larger than 1 when the loading sequence changes from low-level to high-level. On the contrary, the fatigue damage index is less than 1. Source

Xu C.,Beijing Institute of Technology | Zhang J.,Beijing Institute of Technology | Yin X.,Beijing Institute of Technology | Cheng Z.,China North Industries Group Corporation
Inorganic Chemistry | Year: 2016

Twelve metal coordination compounds with two triazole derivatives, namely, {[Mn(HATr)2](ClO4)2}n (1), [Mn(HATr)3]Cl(ClO4) (2), [Co3(ATr)6(H2O)6](ClO4)6·4.5H2O (3), [Co(HATr)3]Cl(ClO4) (4), [Co2Cl2(HATr)2(H2O)2(CH3OH)2]Cl2·2H2O (5), [Ni3(ATr)6(H2O)6](ClO4)6·4.5H2O (6), [Ni(HATr)3]Cl(ClO4) (7), [Ni2Cl2(HATr)2(H2O)4](ClO4)2·4H2O (8), [Ni2(HATr)2(H2O)6](ClO4)4·2H2O (9), {[Zn(HATr)2](ClO4)2}n (10), [Zn(HATr)3]Cl(ClO4) (11), and {[Cd4(HATr)8](CdCl4)Cl2(ClO4)4}n (12), when HATr = 3-hydrazino-4-amino-1,2,4-triazole and ATr = 4-amino-1,2,4-triazole, were prepared under diverse conditions and structurally characterized. Compounds 1, 10 and 12 exhibit one-dimensional zigzag chain structures; 2, 4, 7, and 11 possess mononuclear structures; 3 and 6 display trinuclear structures, while 5, 8, and 9 feature binuclear structures. Hydrogen bonds link these compounds into three-dimensional structures. The thermal stability and energetic properties also were determined. © 2015 American Chemical Society. Source

Discover hidden collaborations