bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Range Extended Electric Vehicle Based on Cruise
Authors: Xu Chuyuan
Published: April 2023

Recently, extended-range electric vehicles are a new solution to energy shortage and environmental pollution, which effectively increases the range of electric vehicles, extends the battery life, and reduces fuel consumption. Therefore, this paper mainly focuses on the design of the EREV powertrain, building a vehicle model by using AVL CRUISE to simulate and verify the calculated parameters of the design.

Analyzing the structural characteristics of the extended-range electric vehicle and determining the vehicle’s basic parameters and performance indexes using the Aratou Free 4WD hybrid as the prototype were the first part. In this part, the drive motor on the power system, battery, and range extender were selected based on the calculated parameters. The AC asynchronous motor, ternary lithium battery, and four-stroke gasoline engine were chosen as the components of the power system in the EREV. Building the vehicle model by using the AVL Cruise and developing the calculation tasks such as cyclic driving conditions, steady-state driving performance analysis, full-load acceleration performance calculation, and hill-climbing performance analysis were the second part. After the above steps, the simulation results analysis report showed that the powertrain design meets the target and potential of electric vehicle development. This paper provides a reference for comparing the dynamic property and economy of the extended-range electric vehicle with traditional fuel vehicles.
Analysis of Tunable Refractive Index Characteristics of the Magnetic Fluid
Authors: Zeng Wenshi
Published: April 2023

The influence of magnetic field intensity(H
MF) on the refractive index of magnetic fluid (n
MF) at room temperature is analyzed. The optical fiber end reflection method based on the Fresnel principle is used to carry out relevant experiments. The corresponding relationship between n
MF and applied magnetic field is studied in detail. n
MF controls characteristic curve of magnetic fluid with a volume fraction of 0.36% is obtained. According to the experimental results, the H
MF sensitivity of MF is about 0.937~0.948 RIU / T.
Spatial positioning method based on UWB antenna array layout
Authors: Yang Jie , Hu Yansi , Sun Dong , Wan Bowen , Sun Yun , Wang Hongxing , Gao Zichen
Published: April 2023

Aiming at the problem of spatial positioning of dynamic targets in traditional power systems, this paper provides a cost controllable and high precision UWB antenna array layout method for spatial positioning to solve the problems of low precision and multiple restrictions of ultra wideband in spatial environment. First, a base station is set in each area. The base station contains a group of UWB antenna arrays composed of multiple antenna pairs. The distance L from the base station with the location tag is accurately measured through the UWB. Then, the UWB antenna array uses the PDOA phase difference principle to measure the direction of the signal. Finally, the spatial azimuth of the UWB signal from the tag to be located relative to the base station is calculated. The feasibility of the proposed method is verified by an example, which can significantly improve the positioning accuracy. The proposed method can provide strong technical support for intelligent operation and maintenance of power system and safe production.
Vector Control of PMSM Based on Improved Sliding Mode Observer and Controller
Authors: Li Xinyan , Xu Hanbin , Wei Yiying , Zheng Yanling , Zhou Yongping
Published: April 2023

This paper presents a sensorless speed control method of permanent magnet synchronous motor (PMSM) applying sliding-mode control theory, to enhance the observation precision and improve robustness of control system. Firstly, an improved full-order sliding mode observer (FSMO) with sigmoid function is gifted to weaken the high-frequency (HF) chattering caused by conventional sliding mode observer (SMO). The quadrature phase-locked loop (PLL) is used to calculate high-precision rotor location and speed, avoiding the use of filter. Then the nonsingular fast terminal sliding mode controller (NFTSMC) in speed controller is introduced to replace traditional proportional integral (PI) controller to improve the dynamic performance of control system. The outcomes verify that the presented control method enhances the overall observation precision, suppresses HF chattering, and increases dynamic and stable state response of PMSM.
Study on Structure health monitoring method of space vehicle based on PVDF piezoelectric film
Authors: Bai Yan , Xiao Chuncheng , Wei Zijian , Yin Lan
Published: April 2023

At present, health monitoring technology of large structures has been paid more and more attention, among which structure measurement system based on PVDF piezoelectric film sensor has been widely used in various fields. To solve the problem that large structural parts of aerospace are easy to be damaged, a load measurement system based on PVDF piezoelectric film sensor is built in this paper given the complex design structure of aerospace. A large cylinder of aerospace is taken as the test part, the stress state of structural parts is measured online, and the corresponding load value is obtained. With the load value, damage to the health state of the structural parts when they are overloaded by external force can be avoided.
Mid-point potential balancing in three-level inverters
Authors: Lyu Mingzhe , Man Chenxi , Zhou Tinglian
Published: April 2023

Three-level inverters are among the best options for high voltage and high-power applications because of their high capacity, high rated voltage, low harmonic content of the output current, and minimal switching losses. However, the issue with mid-point voltage balancing is an inherent drawback of three-level inverters. The unbalanced mid-point voltage of a three-level inverter leads to low harmonics in the output voltage, causing voltage distortion and seriously reducing the power quality. The unbalanced mid-point voltage also puts more voltage strain on the DC bus side and power switching tubes. As a result, this paper analyzes the remedies for NPC-type three-level inverters’ fluctuating neutral potential and offers hardware and software solutions to regulate the potential neutral balance. It outlines the two primary mid-point potential control strategies depending on the SVPWM and SPWM strategies, provides a detailed study of the software approach, and briefly examines the DMWPWM strategy’s best solution. There are several potential applications for the mid-point potential balancing control method. It may significantly enhance the power quality of rectifiers and inverters and has considerable advantages for real-world uses like solar and wind energy production.
Research on multi-sound source localization performance based on leaf-shaped microphone array
Authors: Wang Ningning , Wei Yonghe , Li Zonglin
Published: April 2023

In the research of multi-sound source localization, the geometric rules for the spatial arrangement of microphone arrays play a decisive role. When faced with multiple sound sources with close positions, traditional typical arrays are difficult to accurately locate the desired signals. Therefore, this paper proposes a leaf-shaped microphone array based on the theory of bionic sunflower spiral arrangement. When the incident signals are multiple sound sources with close positions, combined with the delay-sum beamforming algorithm, the performance of the leaf-shaped array is analyzed from the perspective of positioning accuracy and resolution. Compared with the uniform circular array and Arcondoulis spiral array, the results show that the leaf-shaped array has better resolution and anti-interference ability in the case of multiple sound sources with close positions.
Construction Quality Inspection Method of Substation Fabricated Structure Based on 3D Laser Scanning
Authors: Ye Jianqiang , Zhang Xiaochen , Xu Bo
Published: April 2023

The substation construction project is highly professional and comprehensive, requiring multiple disciplines’ cooperation. It is greatly affected by geographical and environmental factors and has the characteristics of high management requirements and difficult quality control in the construction process. Based on the good initial position of the point cloud to be registered, if this requirement cannot be met, the registered point cloud data is prone to the optimal local solution. Thus, this paper introduces three-dimensional laser scanning to detect the construction quality of the substation assembly structure. On this basis, the data registration method realizes the accurate point cloud registration, and the data’s main feature vector is extracted through a linear transformation. Through the spatial transformation of the principal axis direction, the registration of the point cloud number is completed. The problem of the optimal local solution of registration is effectively solved. The point cloud data model is created by actual data acquisition, and the influencing factors of reverse construction of the geometric model are analyzed. The specific implementation scheme is put forward to ensure the accuracy of the geometric model construction. The test verified the reasonable and effective application of 3D laser scanning in the prefabricated building installation. Besides, the effective method of the high-precision point cloud model data output is determined.
Control and Protection Strategy Study of VSC Station Fault at Hybrid HVDC Transmission System
Authors: Tian Qi , Liu Lulu , Zheng Kuan , Su Guoyun , Si Zhilei , Hu Yongjie
Published: April 2023

LCC-VSC UHV hybrid cascaded DC transmission system will face over-voltage problems caused by power surplus when receiving terminal VSC station fault occurs. An over-voltage suppression strategy based on the action input of a high-voltage controllable arrester and the stepwise blocking of non-fault VSC at the receiving end is proposed, and a dynamic simulation test system is built to verify that the stepwise blocking protection scheme can effectively reduce the DC voltage stress of fault VSC by about 25.9%. Based on the test results, the effectiveness of the over-voltage suppression scheme of VSC at the receiving end in practical projects can be demonstrated by analogy.
Design of Lithium Battery Management System of Hydrogen Emergency Vehicle
Authors: Wang Qinbin , Liu Zhigang , Liu Shi , Cai Ri , Liu Ming
Published: April 2023

The hydrogen emergency power supply vehicle is mainly powered by a pure lithium battery power supply. Therefore, the reliable operation of the power supply and the analysis of charging characteristics play an important role. A battery management system for emergency vehicle power supply is designed in this paper. Through the battery management system, battery information collection, battery information analysis, and control management are carried out to realize the reliable operation of the power supply. The battery management system adopts the active equalization method for balance management, which improves the balance efficiency, improves the health status of the power supply, and extends the life of the power battery pack.
Simulation Study of Improved DDSRF-PLL under Distorted Grid Voltage
Authors: Sun Keqiang , Yang Guozhi , Huang Tailin
Published: April 2023

When the grid voltage is distorted and harmonic and DC components are mixed, the phase locking accuracy of decoupled double synchronous reference frame for phase-locked loop (DDSRF-PLL) will be greatly reduced. This paper proposes an improved DDSRF-PLL(IDDSRF-PLL) structure based on Frequency Adaptive Sliding Discrete Fourier Transform (FASDFT) filtering. A cascade SDFT structure is adopted for FASDFT filtering. The SDFT with fixed sliding window width at the front stage extracts the fundamental wave signal of power grid voltage to eliminate the influence of harmonics and DC components. The latter SDFT detects the sliding window width of power grid frequency update in real time through a nonlinear tracking differentiator (TD) to suppress spectrum leakage. Then DDSRFT-PLL is used to separate the positive and negative sequence of the fundamental signal and lock the phase. Finally, the simulation results in Matlab/Simulink verify the correctness and effectiveness of the proposed method.
PV Distribution Network Planning Method Considering the Cost and Effectiveness of Voltage Control
Authors: Shao Jingwei , Hua Ke , Xu Jun , Zhou Weidong , Sun Ran
Published: April 2023

The large-scale grid connection of distributed power sources can save energy, reduce emissions, and improve the flexibility of the power supply, but the volatility and uncertainty of its power output lead to voltage fluctuations and power quality problems, among which voltage problems have become an important factor inhibiting the large-scale access of distributed power sources, posing new challenges to the grid planning and operation. To address the grid voltage crossing problem after PV grid connection, firstly, a multi-time scale voltage control model based on voltage control coefficients is established to achieve maximum network safety and economic satisfaction; the problem is then solved using a variety of group traction differential evolutionary algorithms with the objective function being the minimum annual integrated cost and the maximum percentage of clean energy generation. This method offers a strong theoretical and technical guarantee for the planning of distributed power access to the distribution system.
Analysis of wind power output characteristics and output prediction
Authors: Ren Yiming , Zhou Renjun , Li Jincheng , Qin Zhichao
Published: April 2023

A fuzzy clustering method and a prediction correction method based on the Copula function are used to establish an analytical model of wind power generation output characteristics. It also predicts the expected and corrected values of its power generation to alleviate the pressure on the grid caused by the high proportion of random new energy sources connected to the grid. Based on the natural properties of wind, a new characteristic index based on the traditional load characteristic index and the new energy output curve is proposed to quantify and evaluate the characteristics of new energy power generation. The results show that the method proposed in this paper can effectively reduce the influence of climate change on output prediction; in comparison to the traditional index, the new index is more refined and instructive.
Evaluation of the autonomous and controllable degree of secondary substation equipment based on fuzzy comprehensive evaluation method
Authors: Wang Zhiyuan , Pu Weixing , Zhang Dongxin
Published: April 2023

The demand for autonomy and controllability of substations is increasing, and there is still a lack of specific methods to evaluate the degree of autonomy and controllability of secondary substation equipment. Given the above situation, firstly, the principle of an autonomous and controllable evaluation system is established. On this basis, the factors affecting the autonomous and controllable level of equipment are analyzed in depth, and the specific evaluation indicators of the autonomous and controllable degree of secondary equipment are determined. Then the fuzzy comprehensive evaluation method is used to establish the evaluation model of the degree of autonomy and controllability of secondary substation equipment. Finally, the specific examples are evaluated. The results show that the autonomous and controllable degree of the equipment has indeed increased after the autonomous and controllable improvement, which verifies the accuracy of the evaluation model. The evaluation model can also provide direction and guidance for the autonomous and controllable improvement of secondary equipment in substations.
Transformer DGA Fault Diagnosis Method Based on Stacked Sparse Auto-Encoders
Authors: Peng Yuxuan , Fu Qiang
Published: April 2023

In the field of transformer fault diagnosis, the imbalance of fault samples seriously affects the fault identification performance of the diagnosis model. Focusing on the problems of low accuracy and high leakage rate of diagnosis model caused by unbalanced fault samples of transformer, a transformer fault diagnosis method is proposed. First of all, the Borderline SMOTE algorithm is used to balance the fault data set from a few samples on the boundary, so as to achieve the effect of power transformer fault sample equalization. Secondly, a diagnosis model of the stacked sparse auto-Encoders with the gas in oil as input characteristic parameter is built. Finally, an evaluation system consisting of accuracy rate, recall rate and F1 score is selected to compare the diagnosis effect of the model before and after category equalization, the experiment proves the effectiveness of this method.
Research on the cooperative control strategy of output current in a distributed generation system
Authors: He Li , Sun Jun
Published: April 2023

In the ship degaussing system, a distributed power system is adopted, in which a single power module drives an independent coil load respectively. To ensure the degaussing effect, it is necessary to ensure the dynamic and static integrity of the load current. If an appropriate cooperative control strategy is not designed, the dynamic consistency of output current will be greatly affected by the difference in load. Therefore, this paper designs the cooperative control strategy based on the multi-agent consistency theory and proves the stability and consistency of the control strategy through the theory of discrete state space equation and graph theory. Through the simulation and experiment of multi distributed power system, it is verified that the control strategy has a good effect on improving the output current consistency of the power system.
A method based on rotated object detection to detect defects regarding distance in strain clamps
Authors: Du Qiliang , Zhou Huangze , Qu Fengrui , Tian Lianfang
Published: April 2023

Strain clamps in the transmission line have a vital role. With X-ray inspection in the transmission line, X-ray images to check defects of the tensioning line clip method have already become the mainstream method. In this paper, we concentrate on the strain clamps’ steel anchor end and strand distance defects. We propose a method based on the rotated object detection model RoI Transformer with KFIoU loss to extract the diameter of the steel anchor tube as a reference to determine whether the distance is too long. We first obtain the rotated bounding boxes of the steel anchor and the strand, then calculate the distance between the steel anchor end and the strand and the diameter of the steel anchor by rotated bounding boxes, and finally determine whether there is a defect. Through the study of this essay, the defect detection of strain clamps realizes with high accuracy which has an essential reference for the quality inspection of tension clamp crimping in engineering applications.
Multi-operation state traction control of regional coal-fired and gas-fired combined power generation system
Authors: Wang Pengyu , Yao Senjing , Wei Zhichu , Yang Mingrui , Yang Ping , Chen Yansen , Zhou Yue , Xu Yize
Published: April 2023

The traditional dispatching model and strategy of coal-fired and gas-fired power units are difficult to take into account the minimum total cost of power generation and the stable output of each unit. Therefore, this paper proposes a staged traction control model of coal-fired and gas-fired combined power generation, aiming at the minimum total power generation cost and stable output of the units. Based on the safe operation constraints of the regional coal-fired and gas-fired combined power generation system, the particle swarm optimization algorithm is adopted to solve the traction control strategy of the regional coal-fired and gas-fired combined power generation system in multiple operation states. The example simulation shows that the traction control strategy of regional coal-fired and gas-fired combined power generation systems in multiple operating states can realize flexible, coordinated control of each unit. Based on quickly responding to the change in load demand, it meets the minimum total power generation cost of regional coal-fired and gas-fired combined power generation systems. It makes the unit output stable to prolong the service life of the unit.
Automatic Control System of Manipulator Clamping Angle Based on Machine Vision
Authors: Ren Zhong , Zhang Tieshan
Published: April 2023

In order to shorten the time it takes for the manipulator components to reach the preset position and avoid the behavior state of excessively increasing the gripping angle, an automatic control system for the gripping angle of the manipulator based on machine vision is designed. According to the motion state of the mechanical components of the gripper, the connection sensitivity of the angular position sensor is controlled, and then the tension and pressure control structure is used to complete the on-demand adjustment of the clamping force action form and realize the construction of the application platform environment of the hardware structure of the automatic control system. On this basis, by grabbing the necessary manipulator operation image, following the principle of machine vision, completing the preprocessing, and then combining the kinematic functions to perform the force control switching operation and realizing the gripping force control based on machine vision, and completing the design and application of the automatic control system for the gripping angle of the manipulator. The experimental results show that when the motor driving speed is equal to 2000 PPS,4000 PPS, and 6000 PPS, the consumption time required for the manipulator components to reach the preset position will not exceed 9.5s. Compared with the double closed-loop control system, it is more in line with the application requirements of effectively controlling the behavior of the clamping angle.
Development Status of Space Vector Pulse Width Modulation (SVPWM) Control Method for Multi-Level Inverter
Authors: Zhang Guangyu
Published: April 2023

Inverter has played an important role in power electronics technology since its invention. The traditional 2-level inverter is most widely used due to its simple structure, but it cannot meet the needs of high-voltage and high-power fields anymore. Thus, three-level and multi-level inverters are invented. Although complicated in structure, these two kinds of inverters can output larger voltage, and the voltage distortion rate and the ripple current are smaller. The emergence of different modulation methods also makes up for the defects of multi-level inverters. The improvement and simplification of the control algorithm of space vector pulse width modulation (SVPWM) make multi-level control less complicated. This paper introduces the current status and trends of SVPWM.
Design of AGV Chassis Motion Control System Based on MWorks
Authors: Zhang Dongyang , Zhu Zhixu , Zhang Hualiang
Published: April 2023

With the mature and extensive application of robotics, task-based mobile robots for special environments and high-risk tasks are also gaining more and more attention. To make the task-based mobile robots achieve more precise and difficult work, then, it is particularly important to achieve precise and stable control of the AGV. Therefore, by establishing a mathematical model of AGV and conducting a kinematic analysis, we design a control system that can make AGV achieve stable and accurate motion. The experimental simulation, separated from the traditional foreign simulation software MATLAB, is based on the domestic independently developed virtual simulation experiment environment MWorks. Sysplorer validated the control algorithm and virtual model AGV by digital twinning.
Research on Utility Calculation Method of Pumped Storage Participating in Peak-Shaving Market
Authors: Chen Zhe , Xu Danlei , Geng Lin , Chen Haoxuan , Hao Siyu , Zhuang Baisong
Published: April 2023

With the advancement of the “dual carbon” goal, the proportion of renewable energy in the system has increased significantly. The peak-shaving problem brought about by it has become increasingly significant. As an important flexible power resource, a pumped storage power station has good technical characteristics such as fast response speed, fast ramp rate, and large capacity. However, pumped storage also has problems such as difficult construction, long construction period, and high construction cost. Therefore, it is the current research focus to accurately evaluate the peak-shaving utility of pumped storage for the power system and then rationally plan the construction of pumped storage and fully optimize the utilization of pumped storage. This paper proposes a set of utility evaluation methods for pumping and storage peak regulation through the simulation of the power system and the power market. It can accurately evaluate the utility of pumping storage and peak shaving in various ways to participate in the peak shaving market. Through calculation examples, it can be concluded that when pumping storage participates in the market in an on-demand scheduling mode, the environmental and economic benefits are better than those brought by the load-side response.
Research on Cloud-Edge-Terminal function configuration based on differentiated low-voltage intelligent distribution network
Authors: Xiang Yingyu , Hu Haoqing , Fang Qian , Liu Hongwen , Cheng Tianze
Published: April 2023

At the present, more than 30 low-voltage intelligent distribution rooms have been built in Yunnan Power Grid, covering incoming cabinets, distribution substations, low-voltage switches and environmental monitoring, etc. The intelligent distribution rooms use the Cloud-Edge-Terminal architecture model for intelligent management, monitoring and control of low-voltage distribution rooms but there are generally problems such as low level of heterogeneous data application, insufficient correlation analysis capability, fault location. However, there are problems such as low level of heterogeneous data application, insufficient correlation analysis capability, inaccurate fault location, excessive network load, insufficient sensing capability of sensing terminals and unreasonable configuration. Based on the application model of low-voltage intelligent distribution network of Yunnan power grid, Our paper intends to summarize the experience and methods to support operation and maintenance, fault repair and customer service and study the differentiated low-voltage intelligent distribution Cloud-Edge-Terminal solution to improve the efficiency of intelligent distribution network operation and maintenance.
Multi Agent Interaction Mechanism of Intelligent Network Connection for Interaction Between EV and Power Grid
Authors: Xi Yanjun , Ji Yang , Zhang Xuze , Zhang Jian , Wang Qiang , Meng FanJie
Published: April 2023

As a new type of flexible load, the charging behavior of electric vehicles is random and intermittent in space and time, which puts forward higher requirements for the safe, stable grid operation and power quality. When a large-scale electric vehicle charging load is connected to the power grid, its disordered charging behavior will also bring adverse effects to the power system. From the perspective of charging behavior, the gradual increase of devices such as electric vehicles and charging piles have formed the Internet of Electric Vehicles, power distribution network, and charging equipment Internet of Things. At the same time, more and more charging loads are connected to the grid, and the charging behavior also contains a lot of load information on the grid side. These data are fused through the server, which can provide an economical and reasonable charging strategy for the charging behavior of electric vehicles on the regional grid side.
Cyber-Physical Architecture of Intelligent Interaction Between Electric Vehicle and Power Grid
Authors: Xi Yanjun , Zhang Xuze , Meng Fanjie , Zhang Jian , Wang Qiang , Ji Yang
Published: April 2023

With the increasing penetration rate of electric vehicles, their charging is random and intermittent in space and time, which put forward higher requirements for the safe, stable operation and power quality of the power grid. The information flow and energy flow exist at the same time in the vehicle pile network linkage, and the degree of integration of the three is also getting higher and higher. Based on the hierarchical architecture of cyber-physical system, the fusion model for V2G is established, which is helpful to study relevant strategies to minimize the impact of electric vehicle charging and discharging on the main power grid.
A new indirect measurement method of the electron temperature for the Proto-sphera's pinch plasma
Authors: Iannarelli D. , Napoli F. , Alladio F. , Apruzzese G. , Bombarda F. , Buratti P. , Delfini J. , De Ninno A. , Filippi F. , Fiorucci D. , Ingenito A. , Mannori S. , Micozzi P. , Teofilatto P.
Published: April 2023

This article presents a new method for estimating the electron temperature of the Proto-sphera's screw pinch. The temperature radial profile is obtained by a self-consistent modeling of a 1D MHD equilibrium along with a 0D power balance of the plasma column, given measurements and estimates of the axial pinch plasma current, of the plasma rotational frequency and, at the equatorial plane, of the electron density radial profile, of the edge poloidal magnetic field, of the edge electron temperature and of the neutrals pressure in the vacuum vessel. The plasma is considered in equilibrium with its neutral phase and in constant rotation. A MATLAB code has been developed with the aim of estimating the MHD radial equilibrium profiles, the thermodynamic plasma state and the neutrals profile. The numerical estimates are compared with available experimental data showing a good agreement.
Deformable 3D medical image registration with convolutional neural network and transformer
Authors: Deng Liwei , Zou Yanchao , Huang Sijuan , Yang Xin , Wang Jing
Published: April 2023

Deformable registration of medical images based on deep
learning has been the research focus this year. Convolutional Neural
Network (CNN) and the transformer are the most common backbone and
have been shown to enhance registration accuracy. However, CNN lacks
the ability to contact long-distance information, and the
transformer lacks the ability to capture local
information. Whichever subtle feature loss may lead to disastrous
consequences in the analysis of clinical medicine. This paper
presented a novel registration network named Information
Complementation Network (ICN). We aim to improve the registration
accuracy by complementing the lost information. Pure transformers
can establish long-distance spatial information about the
image. Proposed meshing patch embedding can minimize the loss of
local information and expand the receptive field to extract
long-distance information. The dual-path decoder in ICN is designed
to restore information furthest. We experimented on 3D brain MRI
data and quantitatively compared several excellent registration
models. Compared with conventional methods, the dice coefficient
increased by 3%. Compared with the advanced methods, the dice
coefficient increased by 1%. The number of foldings was reduced by
about 50% without any loss of registration accuracy. Each
evaluation metric of the trained models on liver CT images was
higher than other methods. By fully complementing the lost or
invalid information, ICN achieved higher registration accuracy and
smoother deformation field. The innovation and contribution of this
paper have the potential to be applied to clinical research or
medical image processing.
Over 7200 hours commissioning of RF-driven negative hydrogen ion source developed at CSNS
Authors: Chen W. , Li H. , Lü Y.J. , Cao X.X. , Liu S.J. , Xiao Y.C. , Liao H. , Xue K.J.
Published: April 2023

The China Spallation Neutron Source project Phase-II
(CSNS-II) aims to deliver a proton beam of 500 kW on the tungsten
target. To accomplish this goal, an RF-driven negative hydrogen ion
source was developed to replace the penning ion source used in
CSNS-I. The RF-driven ion source has been put into commissioning on
CSNS accelerator since September 8th, 2021. And it was
shut down on July 26th, 2022, together with the whole
accelerator for the annual maintenance in summer. In this run cycle
it has accumulated service time of over 7200 hours without major
maintenance. The availability of the ion source is above 99.99%,
except for one or two sparks per day of the 50 kV high voltage
platform, each spark causing 1 second trip of the accelerator. The
RF-driven ion source has an external antenna winding around a
silicon nitride plasma chamber, which is quite robust in high
duty-factor operation. In this paper, we present the structure of
the ion source, the improvements over other ion sources, and the
issues met in the commissioning.
A hybrid 3D/2D field response calculation for liquid argon detectors with PCB based anode plane
Authors: Martynenko S. , Pietropaolo F. , Viren B. , Qian X. , Chen H. , Gao S. , Gu W. , Jo J. , Kettell S. , Li Y. , Liu H. , Nayak N. , Yu B. , Yu H. , Zhang C. , Kose U. , Resnati F. , Tufanli S. , Boran F. , Dolek F.
Published: April 2023

Liquid Argon Time Projection Chamber (LArTPC) technology is commonly utilized in neutrino
detector designs. It enables detailed reconstruction of neutrino events with high spatial
precision and low energy threshold. Its field response (FR) model describes the time-dependent
electric currents induced in the anode-plane electrodes when ionization electrons drift nearby. An
accurate and precise FR is a crucial input to LArTPC detector simulations and charge
reconstruction. Established LArTPC designs have been based on parallel wire planes. It allows
accurate and computationally economic two-dimensional (2D) FR models utilizing the translational
symmetry along the direction of the wires. Recently, novel LArTPC designs utilize electrodes
formed on printed circuit board (PCB) in the shape of strips with through holes. The translational
symmetry is no longer a good approximation near the electrodes and a new FR calculation that
employs regions with three dimensions (3D) has been developed. Extending the 2D models to 3D would
be computationally expensive. Fortuitously, the nature of strips with through holes allows for a
computationally economic approach based on the finite-difference method (FDM). In this paper, we
present a new software package pochoir that calculates LArTPC field response for these new
strip-based anode designs. This package combines 3D calculations in the volume near the electrodes
with 2D far-field solutions to achieve fast and precise field response computation. We apply the
resulting FR to simulate and reconstruct samples of cosmic-ray muons and 39Ar decays from a
Vertical Drift (VD) detector prototype operated at CERN. We find the difference between real and
simulated data within 5%. Current state-of-the-art LArTPC software requires a 2D FR which we
provide by averaging over one dimension and estimate that variations lost in this average are
smaller than 7%.
Overestimated global dryland expansion with substantial increases in vegetation productivity under climate warming
Authors: Liu Ziwei , Wang Taihua , Yang Hanbo
Published: April 2023

Drylands are serviced as an essential component of the earth’s ecosystem. The potential changes in dryland areas are of great importance to the environment, but various debates remain as to whether and to what extent drylands are expected to expand. Here we employ a physically-based potential evapotranspiration (E
P) model accounting for vegetation response to climate change to quantify potential changes in dryland areas, on the basis of a commonly used indicator, aridity index (multiyear mean E
P over precipitation). Results show that by the end of this century, drylands will expand slightly by ∼5%, while vegetation productivity will increase by ∼50%. Elevated CO2 slows down the increase rate of E
P that impedes the expansion of drylands, but greatly promotes vegetation growth with increases in both leaf assimilation and canopy foliage. These findings improve our understanding of the potential changes in dryland and their ecological impacts in a warmer climate.
Generalized virial theorem for contact Hamiltonian systems
Authors: Ghosh Aritra
Published: April 2023

We formulate and study a generalized virial theorem for contact Hamiltonian systems. Such systems describe mechanical systems in the presence of simple dissipative forces such as Rayleigh friction, or the vertical motion of a particle falling through a fluid (quadratic drag) under the action of constant gravity. We find a generalized virial theorem for contact Hamiltonian systems which is distinct from that obtained earlier for the symplectic case. The ‘contact’ generalized virial theorem is shown to reduce to the earlier result on symplectic manifolds as a special case. Various examples of dissipative mechanical systems are discussed. We also formulate a generalized virial theorem in the contact Lagrangian framework.
Survival probability of the Grover walk on the ladder graph
Authors: Segawa E , Koyama S , Konno N , Štefaňák M
Published: April 2023

We provide a detailed analysis of the survival probability of the Grover walk on the ladder graph with an absorbing sink. This model was discussed in Mareš et al (2020 Phys. Rev. A
101

032113), as an example of counter-intuitive behaviour in quantum transport where it was found that the survival probability decreases with the length of the ladder L, despite the fact that the number of dark states increases. An orthonormal basis in the dark subspace is constructed, which allows us to derive a closed formula for the survival probability. It is shown that the course of the survival probability as a function of L can change from increasing and converging exponentially quickly to decreasing and converging like L
−1 simply by attaching a loop to one of the corners of the ladder. The interplay between the initial state and the graph configuration is investigated.
Double scaling limits of Dirac ensembles and Liouville quantum gravity
Authors: Hessam Hamed , Khalkhali Masoud , Pagliaroli Nathan
Published: April 2023

In this paper we study ensembles of finite real spectral triples equipped with a path integral over the space of possible Dirac operators. In the noncommutative geometric setting of spectral triples, Dirac operators take the center stage as a replacement for a metric on a manifold. Thus, this path integral serves as a noncommutative analogue of integration over metrics, a key feature of a theory of quantum gravity. From these integrals in the so-called double scaling limit we derive critical exponents of minimal models from Liouville conformal field theory coupled with gravity. Additionally, the asymptotics of the partition function of these models satisfy differential equations such as Painlevé I, as a reduction of the KDV hierarchy, which is predicted by conformal field theory. This is all proven using well-established and rigorous techniques from random matrix theory.
Volatolomics analysis of exhaled breath and gastric-endoluminal gas for distinguishing early upper gastrointestinal cancer from benign
Authors: Xiang Chengfang , Yang Hang , Zhao Zhongjun , Deng Fulong , Lv Yantong , Yang Yanting , Duan Yixiang , Li Wenwen , Hu Bing
Published: April 2023

Exhaled breath and gastric-endoluminal gas (volatile products of diseased tissues) contain a large number of volatile organic compounds, which are valuable for early diagnosis of upper gastrointestinal (UGI) cancer. In this study, exhaled breath and gastric-endoluminal gas of patients with UGI cancer and benign disease were analyzed by gas chromatography-mass spectrometry (GC-MS) and ultraviolet photoionization time-of-flight mass spectrometry (UVP-TOFMS) to construct UGI cancer diagnostic models. Breath samples of 116 UGI cancer and 77 benign disease subjects and gastric-endoluminal gas samples of 114 UGI cancer and 76 benign disease subjects were collected. Machine learning (ML) algorithms were used to construct UGI cancer diagnostic models. Classification models based on exhaled breath for distinguishing UGI cancer from the benign group have area under the curve (AUC) of receiver operating characteristic curve values of 0.959 and 0.994 corresponding to GC-MS and UVP-TOFMS analysis, respectively. The AUC values of models based on gastric-endoluminal gas for UGI cancer and benign group classification are 0.935 and 0.929 corresponding to GC-MS and UVP-TOFMS analysis, respectively. This work indicates that volatolomics analysis of exhaled breath and gastric-endoluminal diseased tissues have great potential in early screening of UGI cancer. Moreover, gastric-endoluminal gas can be a means of gas biopsy to provide auxiliary information for the examination of tissue lesions during gastroscopy.
A comparative study of conventional FRET and light harvesting properties of Rh-110/Rh-6G and Rh-19/Rh-B organic dye pairs impregnated in sol-gel glasses
Authors: Mahato Kapil Dev , Kumar Uday
Published: April 2023

Two different pairs of laser dyes, Rhodamine-110 (Rh-110)/Rhodamine-6G (Rh-6G) and Rhodamine-19 (Rh-19)/Rhodamine-B (Rh-B) (the first dye in each pair as a donor and the second as an acceptor) were impregnated in silica samples prepared by the sol-gel method and spectroscopically studied using absorption and steady-state fluorescence techniques. The critical transfer distance (R0), actual distance (r) between the donor and acceptor, overlap integral [J(

υ
¯

)], FRET (fluorescence resonance energy transfer) efficiency (E), and antenna effect efficiency (AE) were investigated in detail based on the variation in acceptor concentration. The FRET efficiency, antenna effect efficiency, and actual donor-acceptor distance for Rh-110/Rh-6G and Rh-19/Rh-B dye pairs corresponding to acceptor concentration ranges (3.83 to 7.65) × 10−5 M l−1 and (3.71 to 8.34) × 10−5 M l−1, respectively, were found to be in the ranges of 57.38% to 74.89%, 36.97% to 24.13%, 5.44 nm to 4.77 nm, and 77.01%. Furthermore, maximum FRET efficiencies of 85.68% and 87.63% and antenna effect efficiencies of 36.97% and 40.95% for Rh-110/Rh-6G and Rh-19/Rh-B, respectively, were also reported. Our results demonstrate the superior FRET efficiency of Rh-19/Rh-B over Rh-110/Rh-6G dye pair in sol-gel glasses, while the antenna effect efficiency of Rh-110/Rh-6G is higher than that of Rh-19/Rh-B for the same donor to acceptor (D/A) ratio. Finally, Rh-110/Rh-6G is a better energy harvester than the Rh-19/Rh-B dye pair at the common D/A ratio. These results are explained in terms of molecular structure similarity, polarity, and rigidity of donor and acceptor.
3D fluid model analysis on the generation of negative hydrogen ions for negative ion source of NBI
Authors: XING Siyu , GAO Fei , ZHANG Yuru , WANG Yingjie , LEI Guangjiu , WANG Younian
Published: April 2023

A radio-frequency (RF) inductively coupled negative hydrogen ion source (NHIS) has been adopted in the China Fusion Engineering Test Reactor (CFETR) to generate negative hydrogen ions. By incorporating the level-lumping method into a three-dimensional fluid model, the volume production and transportation of H− in the NHIS, which consists of a cylindrical driver region and a rectangular expansion chamber, are investigated self-consistently at a large input power (40 kW) and different pressures (0.3–2.0 Pa). The results indicate that with the increase of pressure, the H− density at the bottom of the expansion region first increases and then decreases. In addition, the effect of the magnetic filter is examined. It is noteworthy that a significant increase in the H− density is observed when the magnetic filter is introduced. As the permanent magnets move towards the driver region, the H− density decreases monotonically and the asymmetry is enhanced. This study contributes to the understanding of H− distribution under various conditions and facilitates the optimization of volume production of negative hydrogen ions in the NHIS.
Melody makers
Authors: Durrani Matin
Published: April 2023

Attempts to use quantum computers for music are a welcome diversion.
Eddington was unequivocal
Authors: O’Raifeartaigh Cormac
Published: April 2023

In reply to Mike Follows’ review of Michael Strevens’ book The Knowledge Machine: How an Unreasonable Idea Created Modern Science.
Playing to the quantum beats
Authors: Ball Philip
Published: April 2023

Computers and digital technology are central to the modern music industry – but what could quantum computers bring to the party? Philip Ball tunes in to an avant-garde band of musicians and scientists who are exploring how quantum computing can be used to make and manipulate music.
From student to mentor to teacher
Authors: Whitehall Ellie
Published: April 2023

Ellie Whitehall explains how her experiences mentoring school pupils while she was an undergraduate physics student encouraged her to train as a professional physics teacher.
Assessment of human activities and its effects on forest management: a survey of charcoal producers in the Sekyere Central District of Ghana
Authors: Lambon John Bokaligidi , Honger Joseph Okani , Anambam David Yakubu
Published: April 2023

A survey to assess the effects and sustainability of charcoal production on the local vegetation cover was conducted in the Sekyere Central District of Ashanti region from December 2017 to April 2018. The study involved the use of structured questionnaires, focus group discussions (FGDs), key informants, secondary data and field observation by reconnaissance survey. The socio-economic survey was to identify who in the district is undertaking charcoal production as an economic venture, how widespread the activity is, and the preferred tree species being harvested to produce charcoal. In the field survey, the vegetation types in the study area were identified in a reconnaissance survey as secondary forests with increasing grassland. The relative abundance of tree species which could be used for charcoal production was also identified and quantified. A 640-meter square plot was delimited and divided into 64 square plots within each of which five-meter quadrats were marked at random and presence or absence was recorded for the individual tree species. The results of the study indicated that charcoal production is widely carried out throughout the district especially in the Afram Plains portion. It is practiced by the Akan and the Sissala ethnic groups who have very little education. Female producers (8%) were less than their male counterparts. Majority (73%) of the producers was 31 and above years whiles those of 30 years and below was 27%. The study revealed that most tree species are becoming rare and are only common in the protected area (Kogyae strict natures reserve) in the district.