摘要：Finite element method is used to study the formations of the penetration jet,the bulge,and the burr in the designed reusable perforating *** attached layer of the soft metal on the perforator is studied for the controlling of the bulge height on the casing of the reusable perforating *** indicate that the shaped charge jet is initially formed in the center of the shaped charge liner and then the material of the liner is driven to the centerline of the liner by the detonation *** attachment of the soft metal layer to the cartridge of the perforator can be beneficial to control the bulge *** design on the blind holes on the casing can affect the burr height formed by the collision between the jet and the *** the increase in the liner angle,the penetration width on the cement wall of the wellbore is increased.

摘要：A novel vibration isolation device called the nonlinear energy sink(NES)with NiTiNOL-steel wire ropes(NiTi-ST)is applied to a whole-spacecraft *** NiTi-ST is used to describe the damping of the NES,which is coupled with the modified Bouc-Wen model of *** NES with NiTi-ST vibration reduction principle uses the irreversibility of targeted energy transfer(TET)to concentrate the energy locally on the nonlinear oscillator,and then dissipates it through damping in the NES with *** generalized vibration transmissibility,obtained by the root mean square treatment of the harmonic response of the nonlinear output frequency response functions(NOFRFs),is first used as the evaluation index to analyze the whole-spacecraft system in the *** optimization analysis of the impact of system responses is performed using different parameters of NES with NiTi-ST based on the transmissibility of ***,the effects of vibration suppression by varying the parameters of NiTi-ST are analyzed from the perspective of energy *** results indicate that NES with NiTi-ST can reduce excessive vibration of the whole-spacecraft system,without changing its natural ***,the NES with NiTi-ST can be directly used in practical engineering applications.

摘要：A design of data monitoring recorder is introduced to ensure the stable work of circuit *** recorder is mainly adopted to collect data of different mechanical properties of circuit breakers for real-time online working in power-industrial labs,and to set up a database including both correct information and fault information for assessing and diagnosing power *** recorder uses the master-slave detection core design which adopts both digital signal processor(DSP) and peripheral interface controller(PIC).Not-AND(NAND) flash memory is adopted as a mass storage unit,and the designed clock is used to identify the data being *** to data and communications between the upper computer and the lower computer are achieved through a universal serial bus(USB) *** of an experiment further illustrate the accuracy and reliability of the data obtained by the proposed recorder.

摘要：A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray photoelectron spectroscopy,and N2 adsorption-desorption were used to characterize the crystalline phase,morphology,particle size,chemical composition,and surface area of the WO3 *** formation of hexagonal（h-WO3） and monoclinic（m-WO3） crystal structures of WO3 at different temperatures or different times was confirmed by XRD.m-WO3 is formed at 600 ℃,while m-WO3 starts to transform into h-WO3 at 800℃.However,h-WO3,which forms at 800℃,may transform into m-WO3 by increasing the calcination temperature to 1000℃.SEM results indicate that m-WO3 particles exhibit a bulky shape with heavy aggregates,while h-WO3 particles exhibit a rod-like ***,m-WO3 crystals are sporadically patched on the surface of the h-WO3 rod-like particles,resulting in the exposure of both m-WO3 and h-WO3 on the *** is observed that the monoclinic phase（m-WO3）/hexagonal phase（h-WO3） junction was fabricated by tuning the calcination temperature and calcination *** relative ratios between m-WO3 and h-WO3 in the phase junction can readily be tailored by control of the calcination *** photocatalytic activities of WO3 with different crystalline phases were evaluated by the photocatalytic degradation of rhodamine B as a model pollutant.A higher photocatalytic activity was observed in the WO3 sample with the m-WO3/h-WO3junction as compared with the sample with only *** improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate owing to the formation of the phase junction,whose presence has been confirmed by HRTEM and photoluminescence spectra.