Notes

Hypoxia- along with hyperoxia-related gene expression dynamics throughout developing crucial windows from the warm gar Atractosteus tropicus.
In this study, a method for reflection-mode soft x-ray absorption spectroscopy was developed to realize three-dimensional chemical-state imaging. Soft x rays from a pinhole were reflected by the sample, and the magnified image was observed with a two-dimensional detector. This technique was applied to a Co film with an Au-island-covered surface to obtain the surface chemical state images with a spatial resolution of several tens of micrometers. Furthermore, the soft x-ray reflection spectra within and outside the Au layer were extracted from the images by changing the photon energy. Distinct differences were observed at the Co absorption edge. By considering anomalous x-ray scattering around the Co L-edges in the simulation, the reflection spectrum near the absorption edge in the nm depth resolution was reproduced. In the region without the Au layer, the results were well reproduced, assuming that 4 nm CoO was formed at the surface. These results demonstrate the feasibility of three-dimensional imaging of the chemical states in multilayer films.Inertial piezoelectric actuators (IPAs) are widely used in micro-nano manipulation, biomedicine, and other fields as the simple structure and excitation signal. However, the step consistency is difficult to guarantee in a large stroke range due to the limited machining accuracy of the mover and inherent roll back, which limits the practical application in these precision fields. Therefore, a step consistency active control method for IPAs is proposed based on bending hybrid motions, which uses embedded strain gauges as the force sensors to acquire the pressure between the mover and the actuator. The IPA is driven by horizontal bending motion, and the pressure can be dynamically adjusted by vertical bending motion to ensure the constant pressure and achieve a constant step. Experiments results show that the maximum standard deviation of the step is 0.41 µm under the active control of 350 Vp-p and 1 Hz driving voltage within 2 mm stroke range in 500 driving cycles, and the maximum standard deviation of the step is 1.14 µm under the non-active control with the same conditions, which show that the proposed method evidently improves the step consistency of IPA in a large stroke range.The measurement of the Raman excitation profile (REP) is of great importance to obtain the energies of van Hove singularities and the lifetime of the excited state involved in the Raman process of semiconductors. In this Note, we develop a simple tunable Raman system based on an ultrafast laser and tunable Raman filters for REP measurement. The system is testified by measuring REP of twisted bilayer graphene, and the corresponding energy of van Hove singularity is determined.We present in this Note a numerical study on the dynamic performance of a Dilation X-ray Imager (DIXI). The DIXI including a photoelectron tube (PT) and a magnetic solenoid is modeled in 3D space. The initial parameters of the photoelectrons are sampled with a Monte Carlo code. The trajectories of the photoelectrons are calculated by using the particle-in-cell method, and the transit time spread (TTS) and temporal magnification are analyzed in detail. We have designed a PT with a double-microstrip structure and compared the performance of the double-microstrip PT with the traditional single-microstrip PT. The results show that the sensitivity of the TTS and the temporal magnification to the emission time of the photoelectrons can be significantly reduced by using the double-microstrip PT, resulting in an improvement of the time window. Selleck BV-6 Therefore, the dynamic performance of the DIXI is improved.We demonstrate successful operation of a continuous flow liquid helium magnetic cryostat (Oxford Instruments, Microstat MO) in closed cycle operation using a modular cryocooling system (ColdEdge Technologies, Stinger). For the system operation, we have developed a custom gas handling manifold and we show that despite the lower cooling power of the cryocooler with respect to the nominal cryostat cooling power requirements, the magnetic cryostat can be operated in a stable manner. We provide the design of the gas handling manifold and a detailed analysis of the system performance in terms of cooling times, magnetic field ramping rates, and vibrations at the sample. Base temperatures can be reached within 10 h while the superconducting magnet can be energized at a ramping rate of 0.5 T/min. Vibrations are measured interferometrically and show amplitudes with a root mean square on the order of 5 nm, permitting the use of the system for sensitive magnetic microscopy experiments.A hybrid deformable x-ray mirror consisting of a mechanical bender and a bimorph deformable mirror has been developed to realize adaptive optical systems, such as zoom condenser optics, for synchrotron-radiation-based x-ray microscopy. In the developed system, both bending mechanisms comprehensively contribute to the formation of the target mirror shape and can narrow the role of piezoelectric actuators, thereby enabling a more stable operation. In this study, the behavior of the bimorph mirror under the clamped condition was investigated, and the sharing of the deformation amount for each bending mechanism was optimized to minimize the amplitude of the voltage distribution of the bimorph mirror.Herein, we evaluated a capacitor dosimeter under development by a manufacturer, which is designed to monitor the entrance dose in x-ray diagnosis and comprises a silicon x-ray diode (Si-XD), a 0.1 µF capacitor, and a dosimeter dock. The Si-XD is a high-sensitivity photodiode optimized for x-ray detection. The dosimeter was charged to 3.30 V using the dock before x-ray irradiation. The charging voltage was reduced by photocurrents flowing through the Si-XD during irradiation, and the discharging voltage was measured. For the fundamental characterization of this capacitor dosimeter, we investigated the x-ray tube-current and tube-voltage dependences of the measured dose using an industrial x-ray tube; the angular dependence was also investigated. A commercially available semiconductor dosimeter (RaySafe ThinX) was used for dose calibration. The doses were proportional to the tube current at a constant tube voltage of 100 kV and increased with increasing tube voltage at a constant tube current of 1.0 mA. The dose difference with respect to the commercially available semiconductor dosimeter was within 1.0% when the tube current was varied and it was within 3.0% when the tube voltage was varied. In the angular dependence measurement, a difference of up to 6.0% was observed as the angle varied from 0° to 355° in steps of 5°. The dose-calibration results indicated that the determination of the initial charging voltage was important for dose conversion using the capacitor dosimeter.The magnetic scalar potential U(r⃗) has an intuitive physical interpretation, representing the electric current I = ΔU, which must be directed between any pair of isocontours along the boundary of a region, differing in potential by ΔU, in order to generate the corresponding magnetic intensity H⃗=-∇⃗U inside the region with no tangential component outside the boundary. This physical significance is exploited to invert the design process of hermetic (fringeless) electromagnetic coils from standard iterative techniques (calculating the magnetic field of refined current distributions) to a procedure for calculating the exact surface currents required to generate a given field configuration. A practical construction algorithm is given to produce the prescribed field in a "Target" region (constrained only by Maxwell's equations) while confining the fringe field to a specified hermetic "Return" region. Example coils are analyzed along with a discussion of the limits of precision of the constructed field.We developed a multi-probe atomic force microscope (MP-AFM) system with up to four probes and realized various functions such as topography mapping, probing electrical property, and local temperature measurement. Each probe mounted on the corresponding probe scanner was controlled independently, and the system employed the optical beam deflection method to measure the deflection of each cantilever. A high-performance MP-AFM system with a compact optical design and rigid actuators was finally established. We demonstrated AFM high-resolution imaging in air and performed four-probe imaging in parallel and multi-functional characterization with the MP-AFM system.A new experimental setup has been developed to investigate the reactions of molecular ions and charged clusters with a variety of projectile beams. An Electrostatic Ion Beam Trap (EIBT) stores fast ions at keV energies in an oscillatory motion. By crossing it with a projectile beam, e.g., an IR laser, molecular reactions can be induced. We implemented a Reaction Microscope (REMI) in the field-free region of the EIBT to perform coincidence spectroscopy on the resulting reaction products. In contrast to prior experiments, this unique combination of techniques allows us to measure the 3D momentum-vectors of ions, electrons, and neutrals as reaction products in coincidence. At the same time, the EIBT allows for advanced target preparation techniques, e.g., relaxation of hot molecules during storage times of up to seconds, autoresonance cooling, and recycling of target species, which are difficult to prepare. Otherwise, the TrapREMI setup can be connected to a variety of projectile sources, e.g., atomic gas jets, large-scale radiation facilities, and ultrashort laser pulses, which enable even time-resolved studies. Here, we describe the setup and a first photodissociation experiment on H2 +, which demonstrates the ion-neutral coincidence detection in the TrapREMI.In order to meet the requirements of hypervelocity launch in the context of defending against space debris and deflecting asteroids, an electrical gun with 200 kJ of storage energy was recently built. The electrical gun is composed of 16 gas spark switch-capacitor modules, and pulse current is transmitted by parallel aluminum plates that are insulated by polyester foils. The capacitance, inductance, and resistance of the RLC circuit of the 200 kJ electrical gun are 80 µF, 10.3 nH, and 2.6 mΩ, respectively. It can generate pulse current with a rise time of 1.33 µs and an amplitude of 5.2 MA when short-circuited at a charging voltage of 70 kV. Hypervelocity flyer launch experiments were carried out on the 200 kJ electrical gun, in which a ϕ20 × 0.5 mm2 Mylar flyer (0.22 g) was accelerated to 10 km/s.We present a permanent ring magnet arrangement that can achieve a tunable axial magnetic field from 1.80(5) to 2.67(9) kG. The apparatus has been designed to accommodate a cylindrical atomic vapor cell of length 25 mm and diameter 25 mm to lie within the bore of the ring magnets, providing an alternative route for imaging through atomic vapors in large magnetic fields. The measured axial magnetic field has an rms variation of less than 4% over the length of vapor cell, while the calculated field inhomogeneity is less than 5% radially and 12% longitudinally across a cylindrical volume with diameter 20 mm and length 25 mm. The instrument consists of layered concentric off-the-shelf N42 neodymium-iron-boron axially magnetized ring magnets. The magnets are organized into four cylindrical brass holders, whose relative separation can be manipulated to achieve the desired magnetic field strength. We present magnetic field computations and Marquardt-Levenberg fits to experimental data and demonstrate excellent agreement between theory and experiment.
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