Measurements of the ^(107)Ag neutron capture cross sections with pulse height weighting technique at the CSNS Back-n facility

Silver indium cadmium(Ag–In–Cd) control rod is widely used in pressurized water reactor nuclear power plants,and it is continuously consumed in a high neutron flux environment. The mass ratio of ^(107)Ag in the Ag–In–Cd control rod is 41.44%. To accurately calculate the consumption value of the control rod, a reliable neutron reaction cross section of the ^(107)Ag is required. Meanwhile,^(107)Ag is also an important weak r nucleus. Thus, the cross sections for neutron induced interactions with ^(107)Ag are very important both in nuclear energy and nuclear astrophysics. The(n, γ) cross section of ^(107)Ag has been measured in the energy range of 1–60 eV using a back streaming white neutron beam line at China spallation neutron source. The resonance parameters are extracted by an R-matrix code. All the cross section of ^(107)Ag and resonance parameters are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00010.

An FPGA-Based Pulse Pile-up Rejection Technique for Photon Counting Imaging Detectors

A novel FPGA-based pulse pile-up rejection method for single photon imaging detectors is reported. Tile method is easy to implement in FPGAs for real-time data processing. The rejection principle and entire design are introduced in detail. The photon counting imaging detector comprises a micro-channel plate （MCP） stack, and a wedge and strip anode （WSA）. The resolution mask pattern in front of the MCP can be reconstructed after data processing in the FPGA. For high count rates, the rejection design can effectively reduce the impact of the pulse pile-up on the image. The resolution can reach up to 140μm. The pulse pile-up rejection design can also be applied to high-energy physics and particle detection.

Investigation into Impedance Measurements for Rapid Capacity Estimation of Lithium-ion Batteries in Electric Vehicles

With the dramatic increase in electric vehicles(EVs)globally,the demand for lithium-ion batteries has grown dramatically,resulting in many batteries being retired in the future.Developing a rapid and robust capacity estimation method is a challenging work to recognize the battery aging level on service and provide regroup strategy of the retied batteries in secondary use.There are still limitations on the current rapid battery capacity estimation methods,such as direct current internal resistance(DCIR)and electrochemical impedance spectroscopy(EIS),in terms of efficiency and robustness.To address the challenges,this paper proposes an improved version of DCIR,named pulse impedance technique(PIT),for rapid battery capacity estimation with more robustness.First,PIT is carried out based on the transient current excitation and dynamic voltage measurement using the high sampling frequency,in which the coherence analysis is used to guide the selection of a reliable frequency band.The battery impedance can be extracted in a wide range of frequency bands compared to the traditional DCIR method,which obtains more information on the battery capacity evaluation.Second,various statistical variables are used to extract aging features,and Pearson correlation analysis is applied to determine the highly correlated features.Then a linear regression model is developed to map the relationship between extracted features and battery capacity.To validate the performance of the proposed method,the experimental system is designed to conduct comparative studies between PIT and EIS based on the two 18650 batteries connected in series.The results reveal that the proposed PIT can provide comparative indicators to EIS,which contributes higher estimation accuracy of the proposed PIT method than EIS technology with lower time and cost.

Determination of Heroin Based on Analyte Pulse Perturbation to an Oscillating Chemical Reaction

A new analytical method is proposed for the determination of heroin based on a sequential perturbation caused by trace amounts of heroin in the Cu(Ⅱ)-catalyzed oscillating reaction between hydrogen peroxide and sodium thiocyanate in an alkaline medium with the aid of a continuous-flow stirred tank reactor(CSTR). The method relies on the linear relationship between the change in oscillation period of the system and the concentration of heroin, with a detecting limit of 4.0×10^(-7) mol/L. The calibration curve fits a linear equation very well when the concentration of heroin is in the range of 2.0×10^(-6)_1.2×10^(-5) mol/L(r=0.9971). This method features good precision(RSD=0.98%). The influences of temperature, injection point, flow rate and reaction variables on the oscillation period were investigated in detail and a possible mechanism of the performance of heroin in the Cu(Ⅱ)-catalyzed oscillating reaction system is also discussed. The proposed method opens a new avenue for the determination of heroin.

Pulsed arterial spin labeling effectively and dynamically observes changes in cerebral blood flow after mild traumatic brain injury

Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient＇s condition and judging prognosis after traumatic brain injury.

A Ka-band Solid-state Transmitter Cloud Radar and Data Merging Algorithm for Its Measurements

This study concerns a Ka-band solid-state transmitter cloud radar, made in China, which can operate in three different work modes, with different pulse widths, and coherent and incoherent integration numbers, to meet the requirements for cloud remote sensing over the Tibetan Plateau. Specifically, the design of the three operational modes of the radar（i.e., boundary mode M1, cirrus mode M2, and precipitation mode M3） is introduced. Also, a cloud radar data merging algorithm for the three modes is proposed. Using one month＇s continuous measurements during summertime at Naqu on the Tibetan Plateau,we analyzed the consistency between the cloud radar measurements of the three modes. The number of occurrences of radar detections of hydrometeors and the percentage contributions of the different modes＇ data to the merged data were estimated.The performance of the merging algorithm was evaluated. The results indicated that the minimum detectable reflectivity for each mode was consistent with theoretical results. Merged data provided measurements with a minimum reflectivity of -35 dBZ at the height of 5 km, and obtained information above the height of 0.2 km. Measurements of radial velocity by the three operational modes agreed very well, and systematic errors in measurements of reflectivity were less than 2 dB. However,large discrepancies existed in the measurements of the linear depolarization ratio taken from the different operational modes.The percentage of radar detections of hydrometeors in mid- and high-level clouds increased by 60% through application of pulse compression techniques. In conclusion, the merged data are appropriate for cloud and precipitation studies over the Tibetan Plateau.

THE ALGORITHMS AND APPLICATIONS FOR DETERMINING PERMEABILITY COEFFICIENTS BY PULSE SPECTRUM TECHNIQUE

The determination of inhomogeneous permeability coefficient was studied as a parameter-control inverse problem for parabolic-type equation in this paper. By virtue of PST, the solution of the inverse problem is converted into an iteration procedure of solving a direct problem and solving a Fredholm integral equation of the first kind. Besides, Tikhonov normalization method is introduced to treat the uncertainty caused by the integral equation. Thus an algorithm for determining inhomogeneous permeability coefficient has been formulated and implemented. Numerical results show: (1) The algorithm presented in the paper is suitable to strongly inhomogeneous seepagel; (2) The additional information needed for solution is merely the seepage velocity on partical boundary, so that drill works can be reduced remarkably; (3) The algorithm is applicable to determining inhomogeneous transmission coefficients in groundwater engineering or other engineering.

Pulse reference-based compensation technique for intensity-modulated optical fiber sensors

We propose a compensation technique based on pulse reference for intensity-modulated optical fiber sensors that can compensate the power fluctuation of the light source, the change of optical components transmission loss, and the coupler splitting ratio. The theoretical principle of this compensation technique is analyzed and a temperature sensor based on fiber coating-covered optical microfiber is carried out to demonstrate the compensation effect. The system noise is measured to be 0.0005 dB with the temperature sensitivity reaching -0.063 dB/℃, and the output drift is 0.006 dB in 2 h at room temperature. The output shows a slight variation （0.0061 dB） when the light source and the common liKht path suffer a 3 dB attenuation fluctuation.

3D visualization using pulsed and CW digital holographic tomography techniques

We outline the use of digital holographic tomography to determine the three-dimensional （3D） shapes of falling and static objects, such as lenslets and water droplets. Reconstruction of digitally recorded inline holograms is performed using multiplicative and Radon transform techniques to reveal the exact 3D shapes of the objects.

The Use of Ultrasound to Detect Sub-surface Defects in Aluminum Pieces

A normal ultrasonic transducer of 5 MHz is modified using different delay lines and wedges design （made from Perspex）. Such modification is for ameliorate the capability of the transducer to detect sub-surface flaws. Some prepared Aluminum pieces were subjected to different crosshead speed （200 and 350 ram/rain）. The ultrasonic pulse echo method was used at room temperature. The measurements have been done before and after each tensile stress. Flaws were found at different distances from the specimen＇s surface. Results showed that such delay lines and wedges were suitable to detect sub-surface flaws that were initiated under the effect of stress. In addition, a crosshead speed increment caused more sub-surface flaws formation.

Effect of Annealing Temperatures on the Structural and Electrical Properties of Laser Induced Plasma for TiO2x-1Bix Thin Films

In this study, Bismuth doped Titanium dioxide thin films were deposited on glass substrates by a pulse laser deposition using laser. The effect of annealing temperature on the structural and electrical properties was investigated. X-ray diffraction pattern for pure and doped titanium dioxide films with different doping different ratio with Bi show that these films have amorphous structure oanvert to polycrystalline structure with annealing and doping and have a good identically with standard peaks for Anatase and Rutile phases. The orientation was at specific direction for Rutile. The crystalline of films increases by the increase of doping ratio. The crystalline increased with annealing temperature. Annealed films at different annealing temperatures have been studied. The results show that these films have two activation energies and by increasing the doping ratio, the activation energies and the conductivity increase. Both the annealing and composition effects on Hall constant, density of electron carders and Hall mobility are studied. Hall Effect measurements show that all films have n- type charge conductivity and the concentration increases while the mobility decreases with doping and annealing.

Improvement of thickness uniformity and elements distribution homogeneity for multicomponent films prepared by coaxial scanning pulsed laser deposition technique

In conventional pulsed laser deposition （PLD） technique, plume deflection and composition distribution change with the laser incident direction and pulse energy, then causing uneven film thickness and composition distribution for a multicomponent film and eventually leading to low device quality and low rate of final products. We present a novel method based on PLD for depositing large CIGS films with uni- form thickness and stoichiometry. By oscillating a mirror placed coaxially with the incident laser beam, the laser＇s focus is scanned across the rotating target surface. This arrangement maintains a constant re- flectance and optical distance, ensuring that a consistent energy density is delivered to the target surface by each laser pulse. Scanning the laser spot across the target suppresses the formation of micro-columns, and thus the plume deflection effect that reduces film uniformity in conventional PLD technique is eliminated. This coaxial scanning PLD method is used to deposit a CIGS film, 500 nm thick, with thickness uniformity exceeding ±3% within a 5 cm diameter, and exhibiting a highly homogeneous elemental distribution.

A Novel Approach for Mitigating Power Quality Issues in a PV Integrated Microgrid System Using an Improved Jelly Fish Algorithm

A two-step methodology was used to address and improve the power quality concerns for the PV-integrated microgrid system. First, partial shading was included to deal with the real-time issues. The Improved Jelly Fish Algorithm integrated Perturb and Obserb (IJFA-PO) has been proposed to track the Global Maximum Power Point (GMPP). Second, the main unit-powered via DC–AC converter is synchronised with the grid. To cope with the wide voltage variation and harmonic mitigation, an auxiliary unit undergoes a novel series compensation technique. Out of various switching approaches, IJFA-based Selective Harmonic Elimination (SHE) in 120° conduction gives the optimal solution. Three switching angles were obtained using IJFA, whose performance was equivalent to that of nine switching angles. Thus, the system is efficient with minimised higher-order harmonics and lower switching losses. The proposed system outperformed in terms of efficiency, metaheuristics, and convergence. The Total Harmonic Distortion (THD) obtained was 1.32%, which is within the IEEE 1547 and IEC tolerable limits. The model was developed in MATLAB/Simulink 2016b and verified with an experimental prototype of grid-synchronised PV capacity of 260 W tested under various loading conditions. The present model is reliable and features a simple controller that provides more convenient and adequate performance.

Effect of Shoushen granule on arterial elasticity in patients with carotid atherosclerosis:a clinical randomized controlled trial

OBJECTIVE: To investigate the effectiveness of Shoushen granule,Chinese herbal preparation,on carotid artery elasticity in patients with carotid atherosclerosis.METHODS: The total of 156 carotid atherosclerosis patients were randomly divided into the intervention group(83 cases,treated with Shoushen granule) and the control group(73 cases,treated with pravastatin). Brachial-ankle pulse wave velocity(ba PWV) and Ankle-Brachial Pressure Index(ABI)were measured by automated arteriosclerosis detector. The changes of common carotid artery intima-media thickness(IMT) and parameters of the carotid artery elasticity in patients,including stiffness parameter(β),pressure-strain elastic modulus(Ep),arterial compliance(Ac),augmentation index(AI),and pulse wave velocity β(PWVβ) were detected by Echo-Tracking(ET) technique before and after 24 week treatment. In the meantime,levels of blood lipid,and liver and renal function were measured respectively.RESULTS: After 24 weeks,ba PWV,IMT and parameters of the carotid artery elasticity(β,Ep,AI and PWVβ) were markedly decreased in intervention group compared with those of before treatment(P < 0.01),but the level of Ac was increased significantly(P < 0.01). And there were no significant differences compared with control group on the same period(P > 0.05).CONCLUSION: In this pilot study,it was demonstrated ET technology and automated arteriosclerosis detector could be used to evaluate carotid artery elasticity effectively,and the action of Shoushen granule on carotid atherosclerosis might be related to the regulation of carotid artery elasticity.

Determination of Ascorbic Acid Using a New Oscillating Chemical System of Lactic Acid-Acetone-BrO_3^--Mn^( 2+)-H_2SO_4

Analyte pulse perturbation (APP) technique was applied to the study of the perturbation of ascorbic acid (AA) on the lactic acid-acetone-BrO - 3-Mn 2+-H 2SO 4 oscillating reaction, and AA was determined using this new oscillating chemical system. Influence of experimental variables was investigated. The linear range lies between 5.0×10 -7- 5.5×10 -5 mol/L, and the precision and throughput were quite good ( 2.43% as RSD, and 8-10 samples/h, respectively). This method was applied to the determination of real samples and the results were satisfactory. Some aspects of the potential mechanism of action of AA on the oscillating systems are discussed.

Bis(4,4′-dimethyl-2,2′-bipyridine)ruthenium(II) Complexes Containing 2-Arylimidazo-phenanthroline: Syntheses, Characterization and Third-order Nonlinear Optical Properties

Four novel mononuclear ruthenium(II) complexes [Ru-(dmb) 2L] 2+ [dmb=4,4′-dimethyl-2,2′-bipyridine, L=imid-azo-[4,5-f]phenanthroline (IP), 2-phenylimidazo-phenanthroline (PIP), 2-(4′-hydroxyphenyl)imidazo-phenanthroline (HOP), 2-(4′-dimethylami- nophenyl)imidazo-phenanthroline (DMNP)] were synthesized and characterized by ES-MS, 1H NMR, UV-vis and electrochemistry. The nonlinear optical properties of the ruthenium(II) complexes were investigated by Z-scan techniques with 12 ns laser pulse at 540 nm, and all of them exhibit both nonlinear optical (NLO) absorption and self-defocusing effect. The corresponding effective NLO susceptibility |χ 3| of the complexes is in the range of 2.68×10 -12-4.57×10 -12 esu.