نتایج جستجو برای: demagnetization loop shape
تعداد نتایج: 318035 فیلتر نتایج به سال:
Femtosecond magnetization phenomena have been challenging our understanding for over a decade. Most experiments have relied on infrared femtosecond lasers, limiting the spatial resolution to a few micrometres. With the advent of femtosecond X-ray sources, nanometric resolution can now be reached, which matches key length scales in femtomagnetism such as the travelling length of excited 'hot' el...
To demagnetize small-scale objects (dimensions less than 1 m) fabricated from ferromagnetic materials, it is standard practice to expose the object to a continuous ac applied magnetic field with a steadily decaying amplitude. For objects of dimensions greater than 10 m, there are problems of scale, and a stepwise procedure is preferred. We have simulated two different stepwise demagnetization t...
The thermal demagnetization of pseudo-single-domain (PSD) magnetite (Fe3O4) particles, which govern the magnetic signal in many igneous rocks, is examined using off-axis electron holography. Visualization of a vortex structure held by an individual Fe3O4 particle (~250 nm in diameter) during in situ heating is achieved through the construction and examination of magnetic-induction maps. Stepwis...
It is widely believed that electron dynamics in the shock front is essentially collisionless and determined by the quasistationary magnetic and electric ®elds in the shock. In thick shocks the electron motion is adiabatic: the magnetic moment is conserved throughout the shock and v? / B. In very thin shocks with large cross-shock potential (the last feature is typical for shocks with strong ele...
In this paper, the effect of alloy composition on the microstructural development of devitrified Nd–Fe–B-based alloys is investigated. While crystallization of simple ternary Nd2Fe14B resulted in a highly variable microstructure and relatively poor demagnetization behavior, alloying additions, notably Ti and C, were found to significantly refine and homogenize the crystallized microstructure. H...
The note describes measurement of NdFeB permanent magnet (PM) material demagnetization induced by high-energy electron radiation. In experiments we compared N40 and N40SH grades from Stanford Magnets Company, which have different intrinsic coercive forces. Dimensions of the tested PM blocks were close to those that will be used for ERL undulator construction. It was found that depending on dire...
In contrast to the experimentally widely used isentropic demagnetization process for cooling to ultra-low temperatures we examine a particular classical model system that does not cool, but rather heats up with isentropic demagnetization. This system consists of several magnetite particles in a colloidal suspension, and shows the uncommon behavior of disordering structurally while ordering magn...
A direct torque control method based on fractional order sliding mode variable structure (DTC-FOSMVS) was proposed for the speed control of a permanent magnet synchronous motor (PMSM). The proposed method in which the space vector pulse width modulation (SVPWM) with fixed switch frequency is applied, reduces the torque and flux ripple, and improves the speed control performance. In order to imp...
This paper uses a method for shape reconstruction of a 2-D homogeneous object with arbitrary geometry and known electrical properties. In this method, the object is illuminated by a Gaussian pulse, modulated with sinusoidal carrier plane wave and the time domains’ footprint signal due to object presence is used for the shape reconstruction. A nonlinear feedback loop is used to minimize the diff...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید