摘要：The attitude control problem of the kinetic kill vehicle is studied in this work. A new mathematical model of the kinetic kill vehicle is proposed, the linear quadratic regulator technique is used to design the optimal attitude controller, and the pulse-width pulse-frequency modulator is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the reaction thrusters. The methods to select the appropriate parameters of pulse-width pulse-frequency are presented in detail. Numerical simulations show that the performance of the LQR/PWPF approach can achieve good control performance such as pseudo-linear operation, high accuracy, and fast enough tracking speed.

摘要：Thermodynamic and kinetic study on TRIP （transformation induced plasticity） steels, cemented carbides and mold steel for plastics were carried out in order to design modern advanced materials. With the sublattice model, equilibrium compositions of ferrite and austenite phases in TRIP steels, as well as volume fraction of austenite at inter-critical temperatures for different time were calculated. Concentration profiles of carbon, manganese, aluminum and silicon in the steels were also estimated in the lattice fixed frame of reference. The effect of Si and Mn on TRIP was discussed according to thermodynamic and kinetic analyses. In order to understand and produce the graded nanophase structure of cemented carbides, miscellaneous phases in the M-Co-C （M= Ti, Ta, Nh） systems and Co-V-C system were modeled. Solution parameters and thermodynamic： properties were listed in detail. The improvement of machining behavior of prehardened mould steel for plastics was obtained by computer-aided composition design. The results showed that the matrix composition of large-section prehardened mould steel for plastic markedly influences the precipitation of non-metallic inclusion and the composition control by the aid of Thermo-Calc software package minimizes the amount of detrimental oxide inclusion. In addition, the modification of calcium was optimized in composition design.

摘要：In the past oral Caribbean and African cultures,performances by the“griots”reminded the community of its heroic *** colonial studies,performance is a way for the colonized people to reconnect with its original soul and language and to become magnificent of creativity like the storyteller Solibo in Chamoiseau’s Solibo Magnifique(Caribbean).In Chamoiseau’s novel,the Black policemen who came to investigate on Solibo’s sudden death during the performance look *** mimic the French colonizers with their“baton”and their racism at thinking evil of the Black community and they provoke *** and the irony it conveys,subverts the formerly ironclad authority of the colonial order(Homi *** in Location of Culture).The Cameroonian writer Werewere Liking-Gnépo also warns the Africans of the danger of wearing the White Mask of the colonizers(like Fanon in Black Skin,White Masks).She demonstrates in her Song/Novel She will be of Jasper and Coral,that while the African Mask empowers the performer of metaphysical powers,the White Mask of colonialism on the contrary weakens the performer who internalizes his inferiority and becomes complicit of his ***,Werewere Liking-Gnépo shows ithat the White Mask of colonialism can be used to mimic the harshness and corruption of the Colonial order and in doing so to bring back regeneration of Africa.

摘要：The Algerian kaolin clay was investigated to remove Zn(II) heavy metal ion from aqueous solution. The effect of contact time, initial metal ion concentration, pH and temperature was experimentally studied in batch mode to evaluate the adsorption capacity, kinetic, thermodynamic and equilibrium. The extent of zinc adsorption increased with increasing initial concentration of adsorbat, pH and temperature. The linear Langmuir and Freundlich models were applied to describe equilibrium isotherms and both models fitted well. The monolayer adsorption capacity for Zn(II) ions was 12.23 mg per g of kaolin clay at pH 6.1 and 25°C. Dubinin-Radushkevich (D-R) isotherm model was also applied to the equilibrium data. Thermodynamic parameters showed that the adsorption of Zn(II) onto kaolin clay was spontaneous and endothermic process in nature. Furthermore, the Lagergren-first-order and pseudo-second-order models were used to describe the kinetic data. The experimental data fitted well the pseudo-second-order kinetic. As a result, the kaolin clay may be used for removal of zinc from aqueous media.

摘要：Split Hopkinson pressure bar (SHPB) has become a frequently used technique to measure the uniaxial compressive stress-strain relation of various engineering materials at high strain-rates. The accuracy of an SHPB test is based on the assumption of uniaxial and uniform stress distribution within the specimen, which, however, is not always satisfied in an actual SHPB test due to the existence of some unavoidable negative factors, e.g., interface friction constrains. kinetic interface friction tests based on a simple device for engineering materials testing on SHPB tests are performed. A kinetic interface friction model is proposed and validated by implementing it into a numerical model. It shows that the proposed simple device is sufficient to obtain kinetic interface friction results for common SHPB tests. The kinetic friction model should be used instead of the frequently used constant friction model for more accurate numerical simulation of SHPB tests.

摘要：对谁放电：男人的面子买车有时候真的是靠冲动。这可中了蒙迪欧致胜的下怀。大多数男人的定力在美女面前为零，而在靓车面前，估计是有过之而无不及。当然，与之相对应的是男人迅速扩大的忍耐力，因为面子。嘿嘿，那可是大事啊!