Notes

Adenosine A2A receptor nerves inside the olfactory lamp mediate odor-guided behaviors inside rodents.
Four similar four-electrode spark gap switches are triggered with the same scheme and synchronized within 10 ns as peak values of currents with jitter as less than 5 ns.Light shift produced by the AC Stark effect is one of the major factors limiting the accuracy and long-term stability of a cold atom interferometer. The first order light shift can be canceled by fixing the power ratio of the Raman beams at a specified value. We report here a new method to stabilize the power ratio of the two Raman lasers with ∼100 kHz locking bandwidth, suppressing the effect of the first order light shift. We first mixed the two Raman lasers (at different optical frequencies) with a reference beam and then used two Schottky diode detectors to extract the corresponding beat note signals for each beam, which are much easier to be manipulated and processed as they are in the microwave band. OT-82 The stability of the power ratio is improved by three orders of magnitude from 5.84 × 10-3 to 3.51 × 10-6 at 1 s averaging time and reaches 1.59 × 10-7 at 10 000 s integrating time when the servo loop is engaged. This method can be used in other precise quantum measurement based on the stimulated Raman transition and can be applied to compact inertial sensors.This paper introduces a new planar flexible hinge of fractal configuration to be incorporated in out-of-plane-motion compliant stages that cover a wide stiffness range. The large-displacement fractal hinge consists of a series of scaled-down, concentric, circular-axis flexible segments that are connected in a folded manner by radial rigid links. In-plane and out-of-plane compliance matrices are derived for fractal hinges with variable planar geometry features. The flexible hinges are assembled in a radial architecture to form compliant stages that can be utilized for piston-type, out-of-plane sensing or actuation. The analytical model calculates the stage active, out-of-plane stiffness, as well as its parasitic, in-plane stiffness. The stage analytical stiffness is confirmed by the experimental testing of a prototype and by finite element simulation. Furthermore, analytical-model simulation is performed to evaluate the variations in the active and parasitic stiffnesses with key geometric parameters, which also enables optimization.High pressure-temperature conditions can be readily achieved through the laser-heated diamond anvil cell (LH-DAC). A stable laser source is required for reliable in situ measurements of the sample, as the sample is small with a thermal time constant of the order of microseconds. Here, we show that the power instabilities typical of CO2 gas lasers used in LH-DAC's are ±5% at the second timescale and ∼±50% at the microsecond timescale. We also demonstrate that the pointing instability of the laser requires either a diffuser or an integrating sphere for reliable total power measurements with small sized detectors. We present a simple solution for stabilizing the power of a CO2 gas laser on the second timescale by the direct modulation of the current across the tube and another solution that stabilizes the power to the microsecond timescale by externally modulating the CO2 laser beam. Both solutions can achieve a ±0.3% power stability.Measurements of the resonant behavior of a cryogenic current comparator (CCC) under a range of damping conditions have been made. A model of conserved thermal-noise energy in resonant systems has been applied showing that, regardless of the value of the damping resistor, the energy stored in the resonance is constant. This finding is presented in the context of the design of high turn CCCs for use in the measurement of small currents where there is an increasing requirement to understand and reduce noise. Various damping methods for CCCs are described and experimental results compared with the theory.The interaction of fuel and lubricant droplets with gaseous fuel/air mixtures close to autoignition is relevant in the context of unwanted early autoignition in spark-ignition internal combustion (IC) engines. To study the influence of droplets on the ignition of fuel/air mixtures independent from the in-cylinder pressure/temperature history, the shock-tube technique in combination with an injection system was established, which enables the generation and injection of single droplets or droplet clusters of n-dodecane and lubricant base oil behind reflected shock waves at pressures and temperatures representative for the compression phase of IC engines. Injected droplets were imaged by high-repetition-rate laser-induced fluorescence. The ignition process was observed by imaging in the visible and UV simultaneously through the shock-tube end wall with a combination of color- and UV-sensitive high-repetition-rate cameras. It was found that the amount and composition of the injected liquid are important factors determining the extent of the interference with the ongoing autoignition of the premixed fuel/air bath gas. For a stoichiometric mixture of primary reference fuels (PRF95) in air, the droplets significantly accelerate ignition especially in the negative temperature coefficient regime at around 760 K. The comparison of the timing of local ignition and the occurrence of volumetric ignition indicates that only in cases where the surrounding gas is close to autoignition, the droplets can trigger early autoignition. This required temporal and spatial coincidence might explain the high level of randomness of early autoignition in engines.Multiwavelength pyrometry (MWP) is one of the most powerful tools for the precise measurement of high temperatures on the surfaces of non-gray materials. However, the unknown spectral emissivity of target materials is the most difficult obstacle to overcome in processing temperature inversion data using MWP. A direct and fast generalized inverse matrix normalization (GIM-NOR) data processing algorithm based on GIM theory for underdetermined equations is proposed in order to minimize the effects arising from unknown emissivity. The shape of the emissivity distribution is obtained so that the channel with the greatest emissivity can be selected in order to obtain a value close to the real temperature. The final inversion accuracy is then further improved using a NOR compensation method. Six kinds of materials with a distribution of emissivities at 1800 K were used to simulate and verify the proposed algorithm. The results show that the average relative error of temperature inversion was 0.63%, obtained within 8 ms computation time using a standard desktop computer, and the accuracy and efficiency were largely unaffected when 5% random noise was inserted into the simulation data. A set of experimental data for rocket nozzle temperature measurements with MWP were also processed based on the proposed novel algorithm. The results show that the relative error on the temperature was less than 0.50%, for a design temperature of 2490 K, and that the processing efficiency was very high, that is, within 9 ms. Simulation and experiment both proved that the proposed efficient data processing algorithm for MWP based on GIM theory was unaffected by emissivity and achieved good inversion precision and fast data processing. Therefore, the proposed new data processing algorithm for MWP data for measuring transient high temperatures has very broad potential applications, and it also provides a theoretical basis for measuring high-temperature fields using MWP.We present a piezoelectric-driven uniaxial pressure cell that is optimized for muon spin relaxation and neutron scattering experiments and that is operable over a wide temperature range including cryogenic temperatures. To accommodate the large samples required for these measurement techniques, the cell is designed to generate forces up to ∼1000 N. To minimize the background signal, the space around the sample is kept as open as possible. We demonstrate here that by mounting plate-like samples with epoxy, a uniaxial stress exceeding 1 GPa can be achieved in an active volume of at least 5 mm3. We show that for practical operation, it is important to monitor both the force and displacement applied to the sample. In addition, because time is critical during facility experiments, samples are mounted in detachable holders that can be rapidly exchanged. The piezoelectric actuators are likewise contained in an exchangeable cartridge.This article reports on a cryogenic setup that can be used for multifunctional experimental purposes. The temperature of the setup can be set from 10 K to 300 K. Different kinds of experiments were carried out in this experimental setup such as (1) luminescence emission, light yield, and decay time measurement under excitation of 266 nm laser and 280 nm LED sources, (2) thermoluminescence (TL) measurement under an x-ray excitation source, (3) scintillation property measurements such as light output, energy resolution, and decay time under 137Cs (662 keV γ-rays) and 241Am (5.4 MeV α) isotope sources, and (4) scintillation measurement under a 90Sr beta source through the continuous single-photon counting technique. The luminescence and scintillation properties of various molybdate and tungstate crystals such as CaMoO4, Na2Mo2O7, Pb2MoO5, CdWO4, and ZnWO4 are characterized and reported in the present work. The TL measurement of a CaMoO4 crystal is carried out from 10 K to 300 K, and various kinetic parameters such as order of kinetics, frequency factor, activation energy, and figure of merit are calculated for different TL peaks. As the temperature goes down from room to 10 K, the light yield of all studied crystals increases. Since the light yield of the crystal increases as temperature decreases toward 10 K, this experimental setup can be used for the characterization of luminescence and scintillation properties of a single crystal for rare event searches such as neutrinoless double-beta decay and dark matter.This paper describes the design, fabrication, and testing of an integrated packaged sensor that is composed of a micro resonant accelerometer and a temperature sensor. The resonant accelerometer with differential configuration consists of double quartz resonators and a silicon substrate. When acceleration is applied along the sensing axis, the inertial force induced by the proof mass will transfer force to the resonators, which causes an opposite frequency shift of the dual quartz resonators. The loaded acceleration can be measured through detecting the differential frequency shift. The symmetric differential configuration response to spurious effects of thermal loading and inelastic effect causing prestress in the resonators is similar, which can be reduced by detecting the differential frequency, effectively. However, during the manufacture and packaging process, the otherness of residual stress in two quartz resonators results in that the response of resonators to temperature variation is not strictly the same. In other words, this temperature drift cannot be eliminated by the structure design. Thus, a temperature sensor and an accelerometer were packaged in a shell together. These novel integrated sensors can measure acceleration and temperature simultaneously. With the testing temperature data, a novel temperature compensation that is a combination of the variable coefficient regression and least squares support vector machine is used for improving the performance of the accelerometer. By means of this compensation and field programmable gate array, a real-time and online compensation is achieved. The tumble testing results indicate that the sensitivity of the accelerometer is ∼16.97 Hz/g. With the temperature compensation, the output drift of the scale factor is improved by 0.605 Hz/g in the full temperature range, which is from 0.072 Hz/g to 0.015 Hz/g. The drift of zero bias is improved from 345 mg to 1.9 mg.
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