FPGA-based position reconstruction method for neutron beam flux spatial distribution measurement in BNCT

A new measurement method for the spatial distribution of neutron beam flux in boron neutron capture therapy(BNCT)is being developed based on the two-dimensional Micromegas detector.To address the issue of long processing times in traditional offline position reconstruction methods,this paper proposes a field programmable gate array based online position reconstruction method utilizing the micro-time projection chamber principle.This method encapsulates key technical aspects:a self-adaptive serial link technique built upon the dynamical adjustment of the delay chain length,fast sorting,a coordinate-matching technique based on the mapping between signal timestamps and random access memory(RAM)addresses,and a precise start point-merging technique utilizing a circular combined RAM.The performance test of the selfadaptive serial link shows that the bit error rate of the link is better than 10-12 at a confidence level of 99%,ensuring reliable data transmission.The experiment utilizing the readout electronics and Micromegas detector shows a spatial resolution of approximately 1.4 mm,surpassing the current method’s resolution level of 5 mm.The beam experiment confirms that the readout electronics system can obtain the flux spatial distribution of neutron beams online,thus validating the feasibility of the position reconstruction method.The online position reconstruction method avoids traditional methods,such as bubble sorting and traversal searching,simplifies the design of the logic firmware,and reduces the time complexity from O(n2)to O(n).This study contributes to the advancement in measuring neutron beam flux for BNCT.

Game Theory Based Model for Predictive Analytics Using Distributed Position Function

This paper presents a game theory-based method for predicting the outcomes of negotiation and group decision-making problems. We propose an extension to the BDM model to address problems where actors’ positions are distributed over a position spectrum. We generalize the concept of position in the model to incorporate continuous positions for the actors, enabling them to have more flexibility in defining their targets. We explore different possible functions to study the role of the position function and discuss appropriate distance measures for computing the distance between the positions of actors. To validate the proposed extension, we demonstrate the trustworthiness of our model’s performance and interpretation by replicating the results based on data used in earlier studies.

Energy distribution extraction of negative charges responsible for positive bias temperature instability

A new method is proposed to extract the energy distribution of negative charges, which results from electron trapping by traps in the gate stack of n MOSFET during positive bias temperature instability（PBTI） stress based on the recovery measurement. In our case, the extracted energy distribution of negative charges shows an obvious dependence on energy,and the energy level of the largest energy density of negative charges is 0.01 eV above the conduction band of silicon. The charge energy distribution below that energy level shows strong dependence on the stress voltage.

The Fourier Transformations of Positive Distributions on Lorentz Group SO(3,1)

With the aid of Plancherel-Godement Theorem, we prove that every positive distributionT onSO (3, 1) which is bi-invariant underSO(3) corresponds to a measure μ on ω=∝σC|s(2-s)>=0∝, and μ can be decomposed intoμ=μ 1+μ 2, whereμ 1 is a bounded measure on 0<=s<=2 andμ 2 is slowly increasing measure on (sχC|Re(s)=1)}

Recognition of multi-carrier OFDM and single-carrier with alpha-stable distribution noise

In order to identify the multi-carrier orthogonal frequency division multiplexing(OFDM) and the single-carrier signal in the non-Gaussian noise environment, different features of the two signals are analyzed in terms of five parameters: generalized normalized fourth-order cumulant, the maximum value of the instantaneous amplitude power spectral density, absolute standard deviation of instantaneous phase on the section with weak signals, and position and numbers of the generalized cyclic spectrum's peak. The recognition method of the multi-carrier OFDM and single-carrier signal is proposed in the environment with alpha-stable distribution noise. Simulation results show that the recognition rate of the multi-carrier OFDM can reach 100% when the mixed signal to noise ratio(MSNR) is greater than-5 dB and the recognition rate can reach 90% for the single-carrier when the MSNR is greater than 2 dB.

Fiber Migration and Distribution of Twist at Different Radial Positions of Rotor Yarn-by Hi-Scope Video Microscope System

This paper describes systematic measurement of fiber migration and distribution pattern of twist at different radial positions of rotor spun yarn mixed tracer fiber by Hi-Scope Video Microscope System. The positions of tracer fibers were measured in three dimensions accurately, and the migration index and the twist distribution at different radial positions of rotor yarn were calculated and analyzed. This research result serves to provide useful references for further study on the structural mechanics of rotor spun yarn.

Experimental Study on the Initial Position Distribution of Taylor Bubbles in Cryogenic Upward Inclined Tubes

An experimental study was carried out to understand the phenomena of the boiling flow of liquid nitrogen in inclined tubes with closed bottom by using the high speed digital camera.The tubes in the experiment are 0.018 m and 0.014 m in inner diameter and 1.0 m in length.The range of the inclination angles is 0-45° from the vertical.The statistical method is employed to analyze the experimental data.The experiment was focused on the effect of the inclination angle on the initial position distribution of Taylor bubbles.The formation criterion of Taylor bubbles was confirmed by analyzing the images of Taylor bubbles.The experimental results show that the initial position of Taylor bubble increased first,and then decreased with the increasing inclination angle,with the maximum at 30°.The standard deviation of the initial position of Taylor bubble in tubes was different with different inner diameters.The lognormal shape was fitted to the measured the initial position distributions of Taylor bubbles in the cryogenic tubes.

A Precision-Positioning Method for a High-Acceleration Low-Load Mechanism Based on Optimal Spatial and Temporal Distribution of Inertial Energy

High-speed and precision positioning are fund a mental requirements for high-acceleration low-load mechanisms in integrated circuit(IC) packaging equipment. In this paper, we derive the transient nonlinear dynamicresponse equations of high-acceleration mechanisms, which reveal that stiff ness, frequency, damping, and driving frequency are the primary factors. Therefore, we propose a new structural optimization and velocity-planning method for the precision positioning of a high-acceleration mechanism based on optimal spatial and temporal distribution of inertial energy. For structural optimization, we first reviewed the commonly flexible multibody dynamic optimization using equivalent static loads method(ESLM), and then we selected the modifled ESLM for optimal spatial distribution of inertial energy; hence, not only the stiff ness but also the inertia and frequency of the real modal shapes are considered. For velocity planning, we developed a new velocity-planning method based on nonlinear dynamic-response optimization with varying motion conditions. Our method was verifled on a high-acceleration die bonder. The amplitude of residual vibration could be decreased by more than 20% via structural optimization and the positioning time could be reduced by more than 40% via asymmetric variable veloci ty planning. This method provides an effective theoretical support for the precision positioning of high-acceleration low-load mechanisms.

Development of alpha surface contamination monitor based on THGEM for contamination distribution

In cases of high radiation emergencies,we propose a surface contamination monitor(SCM)that can quickly measure and pinpoint the contamination distribution in the affected population.Thick gaseous electron multiplier(THGEM)has several advantages,including fast response time and good spatial resolution.Based on new THGEMs,a two-dimensional imaging detector was developed for alpha detection,with a position resolution greater than 3 mm.The detector design and test results are described in this paper.Fast radiation imaging SCMs,with a 40mm×40 mm sensitive area,are currently under development.

Distribution and segregation of dissolved elements in pipeline slab

The chemical composition in a cross section of a high grade pipeline slab was measured point by point （in a scale of 1 μm） using original position statistic distribution analysis （OPA）. The result indicated that negative segregation strips of Si, Mn, Mo, Ni, Cr, Nb, Cu, Ti, and V exist in the two sides 24 mm away from the central line, with a width of 8-12 mm, Negative segregation inside the central line is more severe than that outside the central line, and the highest positive segregation of the elements appears closely by the inner sides of the negative segregation strips. No obvious negative segregation strip of S and P is found. Segregation of the elements in the central area is higher than that in the outer and inner arc areas. The segregation of C, Ti, S, and P is high and that of Cr, Cu, Si, and Mn is low in the slab.

Distributed adaptive direct position determination based on diffusion framework

The conventional direct position determination（DPD） algorithm processes all received signals on a single sensor.When sensors have limited computational capabilities or energy storage,it is desirable to distribute the computation among other sensors.A distributed adaptive DPD（DADPD）algorithm based on diffusion framework is proposed for emitter localization.Unlike the corresponding centralized adaptive DPD（CADPD） algorithm,all but one sensor in the proposed algorithm participate in processing the received signals and estimating the common emitter position,respectively.The computational load and energy consumption on a single sensor in the CADPD algorithm is distributed among other computing sensors in a balanced manner.Exactly the same iterative localization algorithm is carried out in each computing sensor,respectively,and the algorithm in each computing sensor exhibits quite similar convergence behavior.The difference of the localization and tracking performance between the proposed distributed algorithm and the corresponding CADPD algorithm is negligible through simulation evaluations.

Influence of ultra-thin TiN thickness(1.4 nm and 2.4 nm) on positive bias temperature instability(PBTI)of high-k/metal gate nMOSFETs with gate-last process

The positive bias temperature instability（PBTI） degradations of high-k/metal gate（HK/MG） n MOSFETs with thin TiN capping layers（1.4 nm and 2.4 nm） are systemically investigated. In this paper, the trap energy distribution in gate stack during PBTI stress is extracted by using ramped recovery stress, and the temperature dependences of PBTI（90℃,125℃, 160℃） are studied and activation energy（Ea） values（0.13 eV and 0.15 eV） are extracted. Although the equivalent oxide thickness（EOT） values of two TiN thickness values are almost similar（0.85 nm and 0.87 nm）, the 2.4-nm TiN one（thicker Ti N capping layer） shows better PBTI reliability（13.41% at 0.9 V, 90℃, 1000 s）. This is due to the better interfacial layer/high-k（IL/HK） interface, and HK bulk states exhibited through extracting activation energy and trap energy distribution in the high-k layer.

Coseismic slip distribution of 2009 L'Aquila earthquake derived from InSAR and GPS data

To better understand the mechanism of the Mw6.3 L'Aquila(Central Italy) earthquake occurred in 2009,global positioning system(GPS) and interferometric synthetic aperture radar(InSAR) data were used to derive the coseismic slip distribution of the earthquake fault.Firstly,based on the homogeneous elastic half-space model,the fault geometric parameters were solved by the genetic algorithm.The best fitting model shows that the fault is a 13.7 km×14.1 km rectangular fault,in 139.3° strike direction and 50.2° southwest-dipping.Secondly,fixing the optimal fault geometric parameters,the fault plane was extended and discretized into 16×16 patches,each with a size of 1 km×1 km,and the non-uniform slip distribution of the fault was inverted by the steepest descent method with an appropriate smoothing ratio based on the layered crustal structure model.The preferred solution shows that the fault is mainly a normal fault with slight right-lateral strike slip,the maximum slip of 1.01 m is located in the depth of 8.28 km,the average rake is -100.9°,and the total geodetic moment is about 3.34×1018 N·m(Mw 6.28).The results are much closer than previous studies in comparison with the seismological estimation.These demonstrate that the coseismic fault slip distribution of the L'Aquila earthquake inverted by the crustal model considering layered characters is reliable.

Influence of Spray Gun Position and Orientation on Liquid Film Development along a Cylindrical Surface

A method combining computationalfluid dynamics(CFD)and an analytical approach is proposed to develop a prediction model for the variable thickness of the spray-induced liquidfilm along the surface of a cylindrical workpiece.The numerical method relies on an Eulerian-Eulerian technique.Different cylinder diameters and positions and inclinations of the spray gun are considered and useful correlations for the thickness of the liquidfilm and its distribution are determined using various datafitting algorithms.Finally,the reliability of the pro-posed method is verified by means of experimental tests where the robot posture is changed.The provided cor-relation are intended to support the optimization of spray-based coating applications.

Empirical analysis of influence on economic growth of China by income distribution difference

Based on a theoretic hypothesis that income inequality has both positive and negative effect on economic growth, this paper analyzes the influence of income distribution differences on economic growth of China by establishing a multivariate linear regression model. The influence of income distribution difference on the economic growth of China changes with the change of time. During a short period immediately after China implemented reform and opening up policy, income inequality has a positive influence on the economic growth of China. However, along with the passing of time, such positive influence has become weaker and weaker and even convertes into negative effective. This paper proposes several advices with policy to restrain the difference of income distribution from expanding and weaken its negative effect on economic growth of China.

Positive Stable Frailty Approach in the Construction of Dependence Life-Tables

Dependence may arise in insurance when the insureds are clustered into groups e.g. joint-life annuities. This dependence may be produced by sharing a common risk acting on mortality of members of the group. Various dependence models have been considered in literature; however, the focus has been on either the lower-tail dependence alone or upper-tail dependence alone. This article implements the frailty dependence approach to life insurance problems where most applications have been within medical setting. Our strategy is to use the conditional independence assumption given an observed association measure in a positive stable frailty approach to account for both lower and upper-tail dependence. The model is calibrated on the association of Kenyan insurers 2010 male and female published rates. The positive stable model is then proposed to construct dependence life-tables and generate life annuity payment streams in the competitive Kenyan market.

A new approach to obtaining positive-definite Wigner operator for two entangled particles with different masses

Based on our previously proposed Wigner operator in entangled form, we introduce the generalized Wigner operator for two entangled particles with different masses, which is expected to be positive-definite. This approach is able to convert the generalized Wigner operator into a pure state so that the positivity can be ensured. The technique of integration within an ordered product of operators is used in the discussion.

The study of aeroball system for measuring 3D neutron flux distribution in reactor core

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石家庄市无偿献血者感染性指标检测不合格人群特征分析

目的分析石家庄市无偿献血者感染性指标检测不合格人群分布特征,以排除献血的高风险人群,为制定献血者招募策略提供理论依据。方法对2022年河北省血液中心采集的无偿献血者标本进行感染性指标[乙型肝炎病毒表面抗原(HBsAg)、丙型肝炎病毒抗体(抗-HCV)、人免疫缺陷病毒抗体(抗-HIV)、梅毒抗体(抗-TP)、丙氨酸氨基转移酶(ALT)、血液病毒核酸(NAT)]筛查,分析检测不合格标本的人群分布特性,并采用多因素Logistic回归分析其影响因素。结果2022年共检测献血者标本182950份,感染性指标总不合格率为1.21%。性别方面,女性无偿献血者ALT不合格率明显低于男性(P<0.05),但HBsAg、抗-HCV、抗-TP、抗-HIV四项传染性指标不合格率均明显高于男性(P<0.05);年龄方面,ALT不合格率最高者为26~35岁献血者,HBsAg和NAT不合格率最高者为36~45岁献血者,抗-HCV和抗-TP不合格率最高者为46~60岁献血者,抗-HIV为18~25岁献血者;文化程度方面,ALT、抗-HCV、抗-TP、NAT不合格率最高者均为初中文化程度献血者;职业方面,ALT、HBsAg不合格率最高者为农民,抗-TP、抗-HIV不合格率最高者为自由职业者,NAT不合格率最高者为学生和商贸职员;初次献血者的HBsAg、抗-HCV、抗-TP、抗-HIV不合格率明显高于重复献血者(P<0.05)。性别、职业、文化程度、年龄、季节、采血队、献血次数、血型是影响血液筛查阳性率的主要因素。结论献血人群感染指标阳性率分布具有性别、年龄、文化程度、职业、献血频次的分布特征,且受多种因素的影响。应将高风险人群排除在献血队伍之外,提高输血安全。

基于顶板结构断裂特征的煤矿结构充填关键位置确定方法

充填开采是控制岩层移动并降低地表沉降与环境损害的重要途径,而充填材料来源不足和充填成本高昂现成为制约井工煤矿充填开采推广应用的主要瓶颈。探寻重点区域的低充填率靶向充填新方法与配套技术是充填开采的研究热点之一。为解决上述问题,结合煤矿井下结构充填的学术思想,深入研究了顶板岩层断裂特征,明确了顶板岩层破断块体尺寸及铰接形态,识别了破断铰接块体主沉降区域,判定出结构充填的关键位置。结合关键位置确定方法,提出重点控制基本顶最大挠度位置,即板结构潜在张拉断裂位置(塑性铰发育位置)的“工字型”结构充填新方法。结合新阳矿岩层地质参数,借助FLAC^(3D)数值模拟软件,深入分析了工作面采宽和推进方向上顶板岩层内应力、竖直沉降、塑性区分布规律,揭示了不同方案下充填体稳定性演变特征。结果表明:“工字型”充填在节省充填用量的基础上,较垮落式开采减少初采期直接顶沉降量33.47%,与全部充填仅相差2.3%。同时,关键位置充填体能有效应对顶板回转下沉引起的应力集中,保持自身稳定性,实现对顶板的长效支撑。综合分析得到了新阳矿首采工作面初采期“工字型”结构充填最佳充填方案为中部条带长度72 m,宽度7 m,两侧条带长度18 m,宽度6 m,较全部充填可减少充填材料成本33.86万元。该方案形成的密闭空间为1980 m^(3),占总采出空间的44%,可用来储能或碳封存,助力实现零碳绿色开采,推动双碳目标的实现。