The microstructural nanoindentation characteristics of different phases in precision annealed GCr15 steel

This study characterizes the mechanical properties and volume fractions of the different phases in precision annealed GCr15 steel using nanoindentation technology. Experimental results indicate that the nanoindentation hardness of cementite grains is between 14.15 GPa and 17.61 GPa,with a mean value of 15.40 GPa. This hardness is much higher than the hardness of ferrite grains. The nanoindentation hardness of ferrite is between 2.78 GPa and 4.89 GPa, with a mean value of 3.35 GPa. The volume fractions of the different phases were also determined using nanoindentation technology, and the volume fraction of cementite in the steel was identified as 15%.

Enhanced performance of oxygen vacancies on CO_(2) adsorption and activation over different phases of ZrO_(2)

The effect of oxygen vacancies on the adsorption and activation of CO_(2) on the surface of different phases of ZrO_(2) is investigated by density functional theory(DFT)calculations.The calculations show that the oxygen vacancies contribute greatly to both the adsorption and activation of CO_(2).The adsorption energy of CO_(2) on the c-ZrO_(2),t-ZrO_(2) and,m-ZrO_(2) surfaces is enhanced to 5,4,and 3 folds with the help of oxygen vacancies,respectively.Moreover,the energy barrier of CO_(2) dissociation on the defective surfaces of c-ZrO_(2),t-ZrO_(2),and m-ZrO_(2) is reduced to 1/2,1/4,and 1/5 of the perfect surface with the assistance of oxygen vacancies.Furthermore,the activation of CO_(2) on the ZrO_(2) surface where oxygen vacancies are present,and changes from an endothermic reaction to an exothermic reaction.This finding demonstrates that the presence of oxygen vacancies promotes the activation of CO_(2) both kinetically and thermodynamically.These results could provide guidance for the high-efficient utilization of CO_(2) at an atomic scale.

Treatment of 90 patients with scapulohumeral periarthritis in different phases by combining therapy centering on Fu's subcutaneous needling

Objective To observe the efficacy of combining therapy in treatment of 90 patients with scapulohumeral periarthritis in different phases. Method Ninety patients with scapulohumeral periarthritis were treated with Fu＇s subcutaneous needling（FSN） combined with physiotherapy in painful phase, acupotomology and massage in adhesion phase, and appropriate functional exercise in rehabilitation phase. Seven days were considered as one course of treatment, and efficacy evaluation was performed after three courses. Function evaluation of shoulder joint was made. Result The total effective rate was 100%（38/38） in acute phase, 93.5%（29/31） in adhesion phase, and 100%（21/21） in rehabilitation phase. After treatment, the range of motion（ROM） of shoulder joint, pain, muscle force, activities of daily living（ADL） and joint local morphology of the patient have been improved obviously. Conclusion Better clinical efficacy is achieved in treatment of scapulohumeral periarthritis in different phases by combining therapy centering on FSN.

Externalization and internalization of cardiac endothelin receptors during different phases of sepsis in rat

Objective To study the redistribution of ET1 receptors in two subcellular organelles, the sarcolemmal membrane and the light vesicle, of rat heart during the progress of septic shock Methods Male Sprague Dawley rats weighing from 270 to 320?g were randomly divided into three groups: control, early sepsis, and late sepsis Each group included six rats Sepsis was induced by cecal ligation and puncture (CLP) Control rats were sham operated After operation for 9 hours or 18 hours, animals of the three groups were anesthetized with sodium pentobarbital (60?mg/kg IP) and the hearts were removed for preparation of sarcolemma and light vesicle Hemodynamic parameters were determined with polygraph via femoral artery and intraventricular cannula ET1 receptor was assayed by [ 125 I] ET1 binding Results Heart rate, cardiac output and left ventricular +dp/dt max undergo biphasic changes: an increase in early phase of sepsis (9?h after CLP) followed by a decrease in late phase of sepsis (18?h after CLP) Mean arterial blood pressure and left ventricular dp/dt max remained relatively unaltered during early phase of sepsis but was decreased during late phase of sepsis Although septic rat heart exhibited biphasic cardiodynamic changes, myocardial function showed signs of progressive deterioration during the development of sepsis, as indicated by a progressive elevation of LVEDP [ 125 I] ET1 bindings to cardiac membranes exhibited a saturable process with a single component binding characteristic for all three experimental groups In sarcolemmal membrane fraction, the maximum binding capacity (B max ) calculated from scatchard plot was increased 30% ( P <0 01) during early phase of sepsis but decreased 24% ( P <0 01) during late phase of sepsis The affinity [the reciprocal of the dissociation contant (Kd)] for [ 125 I] ET1 binding in sarcolemmal membranes remained unaffected during early and late phases of sepsis In light vesicle fraction, the B max for [ 125 I] ET1 binding was decreased by 19% ( P <0 05) during early phase of sepsis but increased by 38% ( P <0 01) during late phase of sepsis The affinity for [ 125 I] ET1 binding in light vesicles was unaltered in early and late phases of sepsis It should be mentioned that the sum of Bmax of sarcolemmal and light vesicle fractions was increased by 25% ( P <0 01) during early phase of sepsis but was decreased by 17% ( P <0 01) during late phase of sepsis Conclusions These data indicated that a biphasic intracellular redistribution of ET1 receptor in the heart might contribute to the development of the initial hyperdynamic and subsequent hypodynamic state during sepsis

Evaluation of the effects of EPS composite soil replacement on the dynamic performance of caisson structure using shaking table tests

The seismic performance of a caisson structure under two types of models with a saturated sandy foundation(CSS)and an expanded polystyrene(EPS)composite soil foundation(CES)are studied using shaking table tests.The macro phenomena of the two different foundation models are described and analyzed.The effects of the replacement of EPS composite soil on seismic-induced liquefaction of backfill and the dynamic performance of a caisson structure are evaluated in detail.The results show that the excess pore water pressure generation in the CES is significantly slower than that in the CSS during the shaking.The dynamic earth pressure acting on the caisson has a triangular shape.The response of horizontal acceleration,displacement,settlement,and rotation angle of the caisson in the CES is smaller than that in the CSS,which means the caisson in the CES has a better seismic performance.Furthermore,the out-of-phase phenomenon between dynamic earth thrust and inertial force in the CES is more obvious than that in the CSS,which is beneficial to reduce the lateral force and improve the stability of the caisson structure.

Influence on the Lifetime of ^(87)Rb Bose-Einstein Condensation for Far-Detuning Single-Frequency Lasers with Different Phase Noises

We study the influence of the phase noises of far detuning single frequency lasers on the lifetime of Bose-Einstein condensation（BEC）of^（87）Rb in an optical dipole trap.As a comparison,we shine a continuous-wave singlefrequency Ti：sapphire laser,an external-cavity diode laser and a phase-locked diode laser on BEC.We measure the heating and lifetime of BEC in two different hyperfine states：｜F=2,m_F=2〉and｜F=1,m_F=1〉.Due to the narrow linewidth and small phase noise,the continuous-wave single-frequency Ti：sapphire laser has less influence on the lifetime of^（87）Rb BEC than the external-cavity diode laser.To reduce the phase noise of the external-cavity diode laser,we use an optical phase-locked loop for the external-cavity diode laser to be locked on a Ti：sapphire laser.The lifetime of BEC is increased when applfying the phase-Jocked diode laser in contrast with the external-cavity diode laser.

Equivalent comparison and analysis between different nominal frequencies

We analyze the phenomena of phase group synchronization between the different nominal frequency signals and propose a new theory of the equivalent comparison between them. The exact expression of the equivalent comparison is deduced. High resolution frequency measurement and phase comparison can be realized using this theory with the divider. For avoiding the frequency mixing, multiplication and synthesis, the system phase noise is improved and the higher resolution comparison and measurement are achieved between the different nominal frequencies by theory.

Microstructure and Stability of Fe_(73.5) Cu_1Nb_3Si_(13.5)B_9 Alloy at Different Stages of Phase Transformation

The microstructure and the stability of Fe_73.5Cu_1Nb_3Si_13.5B_9 alloy at different stages of phase transformation were investigated through the observation of X-ray difraction and transmission electron microscopy and the measurement of magnetic aftereffect (MAE). It was found that the dependence of the volume fraction of amorphous phase and the MAE in the samples annealed from 450 to 700℃ on the annealing temperature is similar.

Observability of Airborne Passive Location System with Phase Difference Measurements

With a pair of antennas spaced apart, an airborne passive location system measures phase differences of emitting signals. Regarded as cyclic ambiguities, the moduli of the measurements traditionally are resolved by adding more antenna elements. This paper models the cyclic ambiguity as a component of the system state, of which the observability is analyzed and compared to that of the bear- ings-only passive location system. It is shown that the necessary and sufficient observability condition for the bearings-only passive location system is only the necessary observability condition for the passive location system with phase difference measurements, and that when the system state is observable, the cyclic ambiguities can be estimated by accumulating the phase difference measurements, thereby making the observer able to locate the emitter with high-precision.

TRANSVERSE VELOCITY ESTIMATION BASED ON HIGH-ORDER DOPPLER EFFECT OF MOVING OBJECT

The one-order phase of the echo changes if there is relative radial moving between the object and the radar, i.e. , the Doppler effect. The Doppler effect is widely used in radar signal processing. The transverse motion of the object cannot change the one-order phase of the echo, but the high-order phase. The high-order Doppler effect of the transverse moving target is presented and a new algorithm for obtaining the transverse velocity is given. The scalar velocity of a target moving steadily in any direction can be calculated with one-order and two-order items of the echo phase. The calculating method and simulating results are given. As the transverse speed is 900 km/h, the speed calculation error is less than 0. 06% if SNR of echo signal is higher than 0 dB.

Periodical Development Trend of Vertical Greening

The research reviewed the development trend of vertical greening industry and divided it into four stages as follows： demand exploring phase, theory and technology development and application phases, and ripening phase of vertical greening system. The characteristics in different phases were detailed, providing ref- erences for development of vertical greening industry in future.

Kinematics Modeling and Experiments of Pectoral Oscillation Propulsion Robotic Fish

A robotic fish driven by oscillating fins, 'Cownose Ray-I', is developed, which is in dorsoventrally flattened shape without a tail. The robotic fish is composed of a body and two lateral fins. A three-factor kinematic model is established and used in the design of a mechanism. By controlling the three kinematic parameters, the robotic fish can accelerate and maneuver. Forward velocity is dependent on the largest amplitude and the number of waves in the fins, while the relative contribution of fin beat frequency to the forward velocity of the robotic fish is different from the usual result. On the other hand, experimental results on maneuvering show that phase difference has a stronger effect on swerving than the largest amplitude to some extent. In addition, as propulsion waves pass from the trailing edge to the leading edge, the robotic fish attains a backward velocity of 0. 15 m·s^(-1).

Experimental and Theoretical Investigation of Wave Forces on APartially-Perforated Caisson Breakwater with A Rock-Filled Core

The total horizontal and vertical forces acting on a partially-perforated caisson breakwater and their phase difference are investigated in this study. The perforated breakwater sits on the rubble tilled foundation, and has a rock-filled core. An analytical solution is developed based on the eigenfunction expansion and matching method to solve the wave field around the breakwater. The finite element method is used for simulating the wave-induced tlow in the rabble-filled foundation. Experiments are also conducted to study the wave forces on the perforated caissons. Numerical predictions of the present model are compared with experimental resuhs. The phase differences between the total horizontal and vertical forces are particularly analyzed by means of experimental and numerical results. The major factors that affect the wave forces are examined.

Phase Difference Method for DOA Estimation

The phase difference method (PDM) is presented for the direction of arrival (DOA) estimation of the narrowband source. It estimates the DOA by measuring the reciprocal of the phase range of the sensor output spectra at the interest frequency bin. The peak width and variance of the PDM are presented. The PDM can distinguish closely spaced sources with different and unknown center frequencies as long as they are separated with at least one frequency bin. The simulation results show that the PDM has a better resolution than that of the conventional beamforming.

The Real-Time,High Precision Phase Difference Measurement of Electron Density in HL-2A Tokamak

This paper introduces a real-time high precision measurement of phase difference based on Field Programmable Gate Array（FPGA） technology,which has been successfully applied to laser grating interference measurement and real-time feedback of plasma electron density in HL-2A tokamak.It can track the changes of electron density while setting the starting point of the density curve to zero.In a laboratory test,the measuring accuracy of phase difference is less than 0.1°,the time resolution is 80 ns,and the feedback delay is 180 μs.

Plasma Electron Density Measuring and Processing on the J-TEXT Tokamak

Plasma electron density is one of the most fundamental parameters in the study of tokamak plasma physics.The method of plasma electron density measuring and processing on the Joint Texas Experimental Tokamak(J-TEXT) was presented in this paper.The principle of the plasma electron density measuring by hydrogen cyanide(HCN) laser interferometer was introduced.Room temperature triglycine sulface(TGS) detector was used to obtain the beat signal of HCN,and phase difference was measured by high-speed acquisition card DAQ2010.Based on the signal characteristics,a specific HCN processing algorithm was designed to eliminate the baseline offset accurately and process overturns of HCN signals effectively.As a result,plasma electron density with high accuracy and low noise has been obtained during the J-TEXT tokamak experiment.

ACCURACY ANALYSIS OF PASSIVE LOCATION SYSTEM WITH PHASE DIFFERENCE RATE MEASUREMENT

The conventional mono-station passive location techniques of direction finding are low in speed and accuracy, due to the little information available. In this paper, a novel measurement-rate (derivative) of phase difference from a two-element antenna array (interferometer) is introduced, accuracy of a passive location system with this measurement and directions of arrival (DOA) is analyzed, and the Cramer-Rao bound of location error of this system for 3D location is examined by simulations.

Driving characteristics of octagon-type ultrasonic motor

Structure of the octagon-type ultrasonic motor was proposed and designed so as to allow the motor to drive small actuator. The stator of the motor consisted of the octagon shape elastic body and four rectangular plate ceramics. The four ceramics were attached to outer surfaces of the octagon elastic body. The same phase voltages were applied to the ceramics on horizontal surfaces, and 90° phase difference voltages were applied to the ceramics on vertical surfaces. When the AC voltage with 90° phase difference was applied in ceramics, the elliptical displacement of unimorph bars was generated by generating bending vibration. To find the maximum displacement model that generates elliptical displacement at the centers of the inner surfaces, the finite element analysis program ATILA was used. The analyzed results were compared to the experimental results. As a result, the speed and torque are increased linearly by increasing the input voltage and the speed of motors can be controlled by changing the applied voltages.

Pressure Drop Fluctuations in Periodically Fluctuating Pipe Flow

Experiments were conducted to study characteristics of flow when flow is fluctuating.The experimental results showed a phase difference between the flow rate and the pressure drop fluctuations.This phase difference between the fluctuating flow rate and pressure drop was analyzed for laminar flow.Analysis showed that the phase difference changes with the period of the flow fluctuation, the pipe radius, the density and the dynamic viscosity of the liquid.Fluctuating pipe flow was then numerically simulated.Results of the numerical simulation were compared with theoretical values and experimental results.It was shown that, when the flow rate fluctuates with time as a sine wave, the pressure drop fluctuates with the same periodicity, and there is a phase difference between them.

MFPL:Multi-Frequency Phase Difference Combination Based Device-Free Localization

With the popularity of indoor wireless network,device-free indoor localization has attracted more and more attention.Unlike device-based localization where the target is required to carry an active transmitter,their frequent signal scanning consumes a large amount of energy,which is inconvenient for devices with limited energy.In this work,we propose the MFPL,device-free localization(DFL)system based on WiFi distance measurement.First,we combine multi-subcarrier characteristic of Channel State Information(CSI)with classical Fresnel reflection model to get the linear relationship between the change of the length of reflection path and the subcarrier phase difference.Then we calculate the Fresnel phase difference between subcarrier pairs with different spacing from CSI amplitude time series.Finally,we get the change of the length of the reflection path caused by target moving to achieve distance measurement and localization.Using a combination of subcarriers with different spacing to achieve distance measurement effectively broadens the maximum unambiguous distance of the system.To solve the complex non-linear problem of the intersection of two elliptic equations,we introduce Newton's method to transform the non-linear problem into a linear one.The effectiveness of our approach is verified using commodity WiFi infrastructures.The experimental results show our method achieves a median error of 0.87 m in actual indoor environment.