Evaluating the use of three-dimensional reconstruction visualization technology for precise laparoscopic resection in gastroesophageal junction cancer

BACKGROUND Laparoscopic gastrectomy for esophagogastric junction(EGJ)carcinoma enables the removal of the carcinoma at the junction between the stomach and esophagus while preserving the gastric function,thereby providing patients with better treatment outcomes and quality of life.Nonetheless,this surgical technique also presents some challenges and limitations.Therefore,three-dimensional reconstruction visualization technology(3D RVT)has been introduced into the procedure,providing doctors with more comprehensive and intuitive anatomical information that helps with surgical planning,navigation,and outcome evaluation.AIM To discuss the application and advantages of 3D RVT in precise laparoscopic resection of EGJ carcinomas.METHODS Data were obtained from the electronic or paper-based medical records at The First Affiliated Hospital of Hebei North University from January 2020 to June 2022.A total of 120 patients diagnosed with EGJ carcinoma were included in the study.Of these,68 underwent laparoscopic resection after computed tomography(CT)-enhanced scanning and were categorized into the 2D group,whereas 52 underwent laparoscopic resection after CT-enhanced scanning and 3D RVT and were categorized into the 3D group.This study had two outcome measures:the deviation between tumor-related factors(such as maximum tumor diameter and infiltration length)in 3D RVT and clinical reality,and surgical outcome indicators(such as operative time,intraoperative blood loss,number of lymph node dissections,R0 resection rate,postoperative hospital stay,postoperative gas discharge time,drainage tube removal time,and related complications)between the 2D and 3D groups.RESULTS Among patients included in the 3D group,27 had a maximum tumor diameter of less than 3 cm,whereas 25 had a diameter of 3 cm or more.In actual surgical observations,24 had a diameter of less than 3 cm,whereas 28 had a diameter of 3 cm or more.The findings were consistent between the two methods(χ^(2)=0.346,P=0.556),with a kappa consistency coefficient of 0.808.With respect to infiltration length,in the 3D group,23 patients had a length of less than 5 cm,whereas 29 had a length of 5 cm or more.In actual surgical observations,20 cases had a length of less than 5 cm,whereas 32 had a length of 5 cm or more.The findings were consistent between the two methods(χ^(2)=0.357,P=0.550),with a kappa consistency coefficient of 0.486.Pearson correlation analysis showed that the maximum tumor diameter and infiltration length measured using 3D RVT were positively correlated with clinical observations during surgery(r=0.814 and 0.490,both P<0.05).The 3D group had a shorter operative time(157.02±8.38 vs 183.16±23.87),less intraoperative blood loss(83.65±14.22 vs 110.94±22.05),and higher number of lymph node dissections(28.98±2.82 vs 23.56±2.77)and R0 resection rate(80.77%vs 61.64%)than the 2D group.Furthermore,the 3D group had shorter hospital stay[8(8,9)vs 13(14,16)],time to gas passage[3(3,4)vs 4(5,5)],and drainage tube removal time[4(4,5)vs 6(6,7)]than the 2D group.The complication rate was lower in the 3D group(11.54%)than in the 2D group(26.47%)(χ^(2)=4.106,P<0.05).CONCLUSION Using 3D RVT,doctors can gain a more comprehensive and intuitive understanding of the anatomy and related lesions of EGJ carcinomas,thus enabling more accurate surgical planning.

Analysis of the decrease of two-dimensional electron gas concentration in GaN-based HEMT caused by proton irradiation

Gallium nitride(Ga N)-based high electron mobility transistors(HEMTs)that work in aerospace are exposed to particles radiation,which can cause the degradation in electrical performance.We investigate the effect of proton irradiation on the concentration of two-dimensional electron gas(2 DEG)in Ga N-based HEMTs.Coupled Schr¨odinger’s and Poisson’s equations are solved to calculate the band structure and the concentration of 2 DEG by the self-consistency method,in which the vacancies caused by proton irradiation are taken into account.Proton irradiation simulation for Ga N-based HEMT is carried out using the stopping and range of ions in matter(SRIM)simulation software,after which a theoretical model is established to analyze how proton irradiation affects the concentration of 2 DEG.Irradiated by protons with high fluence and low energy,a large number of Ga vacancies appear inside the device.The results indicate that the ionized Ga vacancies in the Ga N cap layer and the Al Ga N layer will affect the Fermi level,while the Ga vacancies in the Ga N layer will trap the two-dimensional electrons in the potential well.Proton irradiation significantly reduced the concentration of 2 DEG by the combined effect of these two mechanisms.

Preliminary clinical application of an adaptive iterative statistical reconstruction algorithm inhead and neck computed tomography angiography with low tube voltage and a low concentration of contrast medium

Objective To evaluate the feasibility of using a low concentration of contrast medium （Visipaque 270 mgl/mL）, low tube voltage, and an advanced image reconstruction algorithm in head and neck computed tomography angiography （CTA）. Methods Forty patients （22 men and 18 women; average age 48.7 ± 14.25 years; average body mass index 23.9 ± 3.7 kg/m^2） undergoing CTA for suspected vascular diseases were randomly assigned into two groups. Group A （n = 20） was administered 370 mgl/mL contrast medium, and group B （n = 20） was administered 270 mgl/mL contrast medium. Both groups were administered at a rate of 4.8 mL/s and an injection volume of 0.8 mL/kg. Images of group A were obtained with 120 kVp and filtered back projection （FBP） reconstruction, whereas images of group B were obtained with 80 kVp and 80% adaptive iterative statistical reconstruction algorithm （ASiR）. The CT values and standard deviations of intracranial arteries and image noise on the corona radiata were measured to calculate the contrast-to-noise ratio （CNR） and signal-to-noise ratio （SNR）. The beam-hardening artifacts （BHAs） around the skull base were calculated. Two readers evaluated the image quality with volume rendered images using scores from 1 to 5. The values between the two groups were statistically compared. Results The mean CT value of the intracranial arteries in group B was significantly higher than that in group A （P 〈 0.001）. The CNR and SNR values in group B were also statistically higher than those in group A （P 〈 0.001）. Image noise and BHAs were not significantly different between the two groups. The image quality score of VR images of in group B was significantly higher than that in group A （P = 0.001）. However, the quality scores of axial enhancement images in group B became significantly smaller than those in group A （P〈 0.001）. The CT dose index volume and dose-length product were decreased by 63.8% and 64%, respectively, in group B （P 〈 0.001 for both）. Conclusion Visipaque combined with 80 kVp and 80% ASiR provided similar image quality in intracranial CTA with 64% radiation dose reduction compared with the use of lopamidol, 120 kVp, and FBP reconstruc-tion.

Using a Tree Ring δ^(13)C Annual Series to Reconstruct Atmospheric CO_2 Concentration over the Past 300 Years

The annual series of δ13C were measured in tree rings of three Cryptomeria fortunei disks （OF-1, OF-2, and OF- 3） collected from West Tianmu Mountain, Zhejiang Province, China, according to cross-dating tree ring ages. There was no obvious decreasing trend of the δ13C annual time series of CF-2 before 1835. However, from 1835 to 1982 the three tree ring δ13C annual series exhibited similar decreasing trends that were significantly （P ≤ 0.001） correlated. The distribution characteristics of a scatter diagram between estimated δ13C series of CF-2 from modeling and the atmospheric CO2 concentration extracted from the Law Dome ice core from 1840 to 1978 were analyzed and a curvilinear regression equation for reconstructing atmospheric CO2 concentration was established with R2 = 0.98. Also, a test of independent samples indicated that between 1685 and 1839 the reconstructed atmospheric CO2 concentration .using the δ13C series of CF-2 had a close relationship with the Law Dome and Siple ice cores, with a standard deviation of 1.98. The general increasing trend of the reconstructed atmospheric CO2 concentration closely reflected the 10ng-term variation of atmospheric CO2 concentration recorded both before and after the Industrial Revolution. Between 1685 and 1840 the evaluated atmospheric CO2 concentration was stable, but after 1840 it exhibited a rapid increase. Given a longer δ13C annual time series of tree rings, it was feasible to rebuild a representative time series to describe the atmospheric CO2 concentration for an earlier period and for years that were not in the ice core record.

GREEN FUNCTION ON TWO-PHASE SATURATED MEDIUM BY CONCENTRATED FORCE IN TWO-DIMENSIONAL DISPLACEMENT FIELD

The Green function on two-phase saturated medium by concentrated force has a broad and important use In seismology, seismic engineering, soil mechanics, geophysics, dynamic foundation theory and so on. According to the Green function on two-phase saturated medium by concentrated force in three-dimentional displacement field obtained by Ding Bo-yang et al., it gives out the Green function in two-dimensional displacement field by infinite integral method along x(3)-direction derived by De Hoop and Manolis. The method adopted in the thesis is simpler. The result will be simplified to the boundary element method of dynamic problem.

Declined trends of chlorophyll a in the South China Sea over 2005–2019 from remote sensing reconstruction

Chlorophyll a concentration(CHL)is an important proxy of the marine ecological environment and phytoplankton production.Long-term trends in CHL of the South China Sea(SCS)reflect the changes in the ecosystem’s productivity and functionality in the regional carbon cycle.In this study,we applied a previously reconstructed 15-a(2005–2019)CHL product,which has a complete coverage at 4 km and daily resolutions,to analyze the long-term trends of CHL in the SCS.Quantile regression was used to elaborate on the long-term trends of high,median,and low CHL values,as an extended method of conventional linear regression.The results showed downward trends of the SCS CHL for the 75th,50th,and 25th quantile in the past 15 a,which were−0.0040 mg/(m^(3)·a)(−1.62%per year),−0.0023 mg/(m^(3)·a)(−1.10%per year),and−0.0019 mg/(m^(3)·a)(−1.01%per year).The negative trends in winter(November to March)were more prominent than those in summer(May to September).In terms of spatial distribution,the downward trend was more significant in regions with higher CHL.These led to a reduced standard deviation of CHL over time and space.We further explored the influence of various dynamic factors on CHL trends for the entire SCS and two typical systems(winter Luzon Strait(LZ)and summer Vietnam Upwelling System(SV))with single-variate linear regression and multivariate Random Forest analysis.The multivariate analysis suggested the CHL trend pattern can be best explained by the trends of wind speed and mixed-layer depth.The divergent importance of controlling factors for LZ and SV can explain the different CHL trends for the two systems.This study expanded our understanding of the long-term changes of CHL in the SCS and provided a reference for investigating changes in the marine ecosystem.

Value of liver computed tomography with iodixanol 270, 80 kVp and iterative reconstruction

AIM: To evaluate the image quality of hepatic multidetector computed tomography(MDCT) with dynamic contrast enhancement. METHODS: It uses iodixanol 270 mg/m L(Visipaque 270) and 80 kVp acquisitions reconstructed with sinogram affirmed iterative reconstruction(SAFIRE?) in comparison with a standard MDCT protocol. Fiftythree consecutive patients with known or suspected hepatocellular carcinoma underwent 55 CT examinations, with two different four-phase CT protocols. The first group of 30 patients underwent a standard 120 kVp acquisition after injection of Iohexol 350 mg/m L(Accupaque 350~?) and reconstructed with filtered back projection. The second group of 25 patients underwent a dual-energy CT at 80-140 kVp with iodixanol 270. The 80 kVp component of the second group was reconstructed iteratively(SAFIRE?-Siemens). All hyperdense and hypodense hepatic lesions ≥ 5 mm were identified with both protocols. Aorta and portal vessels/liver parenchyma contrast to noise ratio(CNR) in arterial phase, hypervascular lesion/liver parenchyma CNR in arterial phase, hypodense lesion/liver parenchyma CNR in portal and late phase were calculated in both groups.RESULTS: Aorta/liver and focal lesions altogether/liver CNR were higher for the second protocol(P = 0.0078 and 0.0346). Hypervascular lesions/liver CNR was not statistically different(P = 0.86). Hypodense lesion/liver CNR in the portal phase was significantly higher for the second group(P = 0.0107). Hypodense lesion/liver CNR in the late phase was the same for both groups(P = 0.9926).CONCLUSION: MDCT imaging with 80 kVp with iterative reconstruction and iodixanol 270 yields equal or even better image quality.

Fatigue life prediction of workpiece with 3D rough surface topography based on surface reconstruction technology

The fatigue performance of a workpiece depends on its surface quality.In traditional fatigue life prediction,the effect of surface quality is commonly accounted for by using empirical correction factors,which is imprecise when safety is of great concern.For surface quality,the surface topography is an important parameter,which introduces stress concentration that reduces the fatigue life.It is not feasible to test the stress concentration of different surface topographies.On the one hand,it is time-consuming and high-cost,and on the other hand,it cannot reflect the general statistical characteristics.With the help of surface reconstruction technology and interpolation method,a more efficient and economic approach is proposed,where FE simulation of workpiece with the reconstructed surface topography is used as a foundation for fatigue life prediction.The relationship between surface roughness(Sa)and fatigue life of the workpiece is studied with the proposed approach.

Individualized Design of the Ventilator Mask based on the Residual Concentration of CO2

OSAHS(Obstructive Sleep Apnea Hypopnea Syndrome)is a respiratory disease mainly characterized by limited and repeated pauses of breathing in sleep.Currently,the optimal treatment is to apply CPAP(Continuous Positive Airway Pressure)ventilation on the upper airway of the patient through a household respiratory machine.However,if the ventilator mask is designed improperly,it might cause the residue and repeated inhalation of CO2,which will exert an adverse impact on the therapeutic effect.Present research numerically analyzed the CO2 transportation inside a commercial ventilator mask(Mirage SoftGel,ResMed,Australia)based on the reconstructed 3D numerical model of a volunteer's face and performed the improved design of the ventilator mask in terms of the CO2 residual concentration below the nostrils.The fluid dynamic analyses showed that at the end time of expiratory,the CO2 residual concentration below the nostrils is close to 4%.To improve the therapeutic effect,we changed the position of the exhaust holes and found that by moving the exhaust holes to the bottom of the ventilator mask,the CO2 residual concentration below the nostrils would be reduced to no more than 1%.This study established a near physiological computational model and provided a new method for the individualized design of the commercial ventilator mask.

基于组合时域特征提取和Stacking集成学习的燃煤锅炉NO_(x)排放浓度预测

为提高火电厂锅炉出口NO_(x)排放浓度的预测精度,提出一种考虑组合时域特征的Stacking集成学习模型。首先,为挖掘数据深层信息,采用时序分析、完全自适应噪声集合经验模态分解(complete ensemble empirical mode decomposition with adaptive noise analysis,CEEMDAN)和统计学计算数据标准差、偏度等特征的方法进行组合时域特征提取以构建重构数据;其次,考虑到重构数据中存在的冗余变量对模型的精度有所影响,利用遗传算法(genetic algorithm,GA)对重构数据进行特征降维;最后,为充分发挥各个模型的优势以提高模型的预测精度,构建以极限学习机(extreme learning machines,ELM)、深度神经网络(deep neural networks,DNN)、多层感知器(multilayer perceptron,MLP)、极限梯度提升算法(extreme gradient boosting,XGBoost)为基模型和以回声状态网络(echo state network,ESN)为元模型的Stacking集成学习NOx排放浓度预测模型。实验结果表明:该预测模型在不同数据集下都有着不错的预测效果,预测误差均小于2%,能够对锅炉NOx排放浓度实现精准预测。

类固醇雌激素在一体化MBBR中去除效果及受纳水体生态风险评价

为了评估农村污水处理系统对类固醇雌激素(SEs)的去除效能,以苏北某村级污水站为研究对象,对一体化MBBR进行改造,分析改造前、后污水站进出水SEs浓度及去除率,探究影响SEs去除率的因素,并对尾水受纳水体SEs生态风险进行评价。结果表明:当水力停留时间为20 h时,出水COD、NH_(3)-N、TN、TP平均质量浓度分别为12.98、1.92、12.18和0.22 mg/L,出水达到GB 18918—2002《城镇污水处理厂污染物排放标准》一级A标准。基于此,检测进水雌酮(E1)、雌二醇(E2)和乙炔基雌二醇(EE2)的质量浓度分别在9.1~31.5、4.0~23.4、未检出~6.7 ng/L范围,SEs去除效果明显提高。延长水力停留时间,提高生化段污泥浓度,及夏季的高温环境均有利于SEs去除;尾水受纳水体中E1生态风险最高,需要重点关注。

基于BP神经网络的大气污染物浓度预测模型

针对目前大气污染物浓度预测精度不高的问题,本文提出了一种大气污染物浓度预测模型。对大气污染物浓度时间序列进行相空间重构,采用C-C法计算延迟时间和嵌入维数,在此基础上构建了网络结构为5-11-1的BP神经网络大气污染物浓度预测模型。采用某市SO2浓度监测数据进行仿真分析,并将BP神经网络的污染物浓度预测模型结果与SVM模型和ELM模型进行对比,BP神经网络对测试集的预测结果的均方根误差和平均相对误差分别为0.298和4.35%,预测精度更高,验证了本文所提污染物浓度预测模型的正确性和实用性。

The forward and inverse problem of cardiac magnetic fields based on concentric ellipsoid torso-heart model

This paper constructs a concentric ellipsoid torso-heart model by boundary element method and investigates the impacts of model structures on the cardiac magnetic fields generated by both equivalent primary source--a current dipole and volume currents. Then by using the simulated magnetic fields based on torso-heart model as input, the cardiac current sources--an array of current dipoles by optimal constrained linear inverse method are constructed. Next, the current dipole array reconstruction considering boundaries is compared with that in an unbounded homogeneous medium. Furthermore, the influence of random noise on reconstruction is also considered and the reconstructing effect is judged by several reconstructing parameters.

Defect-induced Surface and Interface Reconstruction in Novel Two-dimensional Materials Revealed by Low Voltage Scanning Transmission Electron Microscopy

Two-dimensional(2 D) materials attracted substantial attention due to their extraordinary physical properties resulting from the unique atomic thickness. 2 D materials could be considered as material systems with flat surfaces at both sides, while the van der Waals gap is a natural out-of-plane interface between two monolayers. However, defects are inevitably presented and often cause significant surface and interface reconstruction, which modify the physical properties of the materials being investigated. In this review article, we reviewed the effort achieved in probing the defect structures and the reconstruction of surface and interface in novel 2 D materials through aberration corrected low voltage scanning transmission electron microscopy(LVSTEM). The LVSTEM technique enables us to unveil the intrinsic atomic structure of defects atom-by-atom, and even directly visualize the dynamical reconstruction process with single atom precision. The effort in understanding the defect structures and their contributions in the surface and interface reconstructions in 2 D materials shed light on the origin of their novel physical phenomenon, and also pave the way for defect engineering in future potential applications.

基于二维吸收光谱重建的数值迭代算法的比较

基于可调谐激光吸收光谱的二维温度和浓度分布重建对于燃烧诊断具有重要意义,而数值迭代算法在温度和组分浓度的重建中起着重要作用。通过对比发现自适应迭代算法和最小二乘QR分解算法对于重建二维温度和气体浓度分布具有很好的优势。研究表明,波长7 154.35, 7 153.75, 7 185.60和7 444.36 cm^(-1)四条H_(2)O的吸收谱线,非常适合测量高温预混火焰中的温度和水蒸气浓度分布。与7 444.36, 7 185.60, 7 154.35和7 153.75 cm^(-1)处的吸收谱线相比,CO_(2)和CH_(4)的光谱吸光非常微弱,在该波段O_(2)和CO基本没有吸收,因此燃烧环境中CO_(2), CH_(4), O_(2)和CO等气体对于H_(2)O吸收谱线基本没有影响。通过比较不同算法的最优松弛因子、计算时间和重建误差等,发现与最小二乘QR分解算法相比,自适应迭代算法具有更好的重建质量和更短的计算时间。在自适应迭代算法的基础上进一步比较了不同吸收线对(7 444.36和7 185.60, 7 154.35和7 153.75 cm^(-1))在射线束为16, 32, 48和64时的二维重建结果。结果表明,采用吸收谱线7 153.75和7 154.35 cm^(-1)得到的重建结果优于吸收谱线7 185.60和7 444.36 cm^(-1)的重建结果。随着激光束的增加,重建结果越来越接近模型假定的温度和浓度分布。考虑到有限的测量空间和重建精度,分析认为32束的光路布置更适合实际火焰的二维温度和浓度重建。为了分析自适应迭代算法对不同温度和浓度分布的重建能力,进一步模拟了双峰温度和浓度分布。结果表明,随着射线束的增加,温度的重建误差总是大于浓度的重建误差,表明射线数对温度的影响更为明显。在双峰分布中,投影射线束为16时的重建误差最大,但此时的重建结果也能反映温度和浓度的分布趋势。

煤矿瓦斯浓度预测的ANFIS方法研究

将时间序列分析方法与自适应神经模糊推理系统(ANFIS)结合,构建煤矿瓦斯浓度的预测模型.根据Takens理论,重构煤矿瓦斯浓度相空间,分别采用互信息法确定相空间时延和假近邻法确定相空间维数;然后在重构相空间中,运用自适应神经模糊推理系统构建煤矿瓦斯浓度的预测模型,并应用混合学习算法整定模型参数.结果表明,得到的模型训练和检验均方根误差分别为0.021 4和0.021 6,充分体现了ANFIS具有显著的学习能力和良好的泛化能力,同时也表明该预测模型是切实可行的.

基于混沌时间序列的瓦斯浓度预测研究

近年来各种矿难频发,特别是瓦斯事故时见于报端。瓦斯事故通常伴随着较高的瓦斯浓度,因此,预测未来时刻的瓦斯浓度是预测瓦斯事故的有效手段,对煤矿的安全生产具有十分重要的意义。对混沌理论中的C-C方法进行简化,并用这种方法对5大煤矿的瓦斯浓度监测数据构成的时间序列进行相空间重构,依据数据的实际情况确定其最佳时延和嵌入维,然后用加权一阶局域法对下一时刻的瓦斯浓度进行预测。实验结果表明瓦斯浓度时间序列具有明显的混沌特性,且当时间序列长度为500时,计算量适中且预测结果较优,对500个异常瓦斯浓度预测的均方误差达到0.122024,从而可用于瓦斯事故的预测,为煤矿及时采取通风等措施提供决策依据。

培养基钙浓度对复方壳多糖组织工程皮肤基底膜构建的形态学研究

目的寻找最适于组织工程皮肤生长及基底膜构建的体外培养基钙浓度。方法按照鲁元刚等建立的方法制备复方壳多糖组织工程皮肤,根据培养基钙浓度不同,分为1.00、1.45、1.65和1.95mmol/L四组。在37℃、5%CO2及90%以上湿度孵箱内浸没培养3d后,将培养物置于不锈钢筛网上进行气-液界面三维培养,每天换液1次。培养7、15d,行HE、PAS染色观察组织工程皮肤的组织学特性;并利用免疫组织化学染色对基底膜的主要成分——型胶原进行观察,评价基底膜构建情况。结果各组组织工程皮肤组织学观察类似正常皮肤,有分化良好的表皮和致密真皮,但1.95mmol/L组表皮分化较其他组更好;1.00、1.45及1.65mmol/L组角化层外侧常伴未角化的角质形成细胞,1.95mmol/L组表皮细胞角化完全,且与颗粒层细胞结合牢固。PAS染色显示各组真、表皮间有紫红色带状结构;免疫组织化学染色显示真皮与表皮间型胶原反应呈阳性,且1.95mmol/L组阳性反应强于1.00mmol/L组。结论钙浓度为1.95mmol/L的培养基最适合于复方壳多糖组织工程皮肤生长及基底膜构建。

颗粒浓度和光学厚度对火焰温度场重建的影响

利用彩色CCD摄像机重建火焰三维温度场分布是一项具有广泛应用前景的研究课题。目前,此项研究的重点集中于在假设燃烧中颗粒的浓度已知的条件下,求取温度的分布。但是,这样的模型没有考虑到火焰中颗粒的浓度(对应于光学厚度)对测量带来的影响。基于CCD摄像机得到的辐射能图像,本文利用三维吸收、发射和各向异性散射介质温度场重建的模型,根据燃煤锅炉数值计算结果,主要考察了颗粒浓度和光学厚度对温度场重建的影响。采用最小二乘QR分解(LSQR)对重建方程进行了求解,较好的克服了重建问题的病态性对结果的影响。结果表明,在一定的颗粒浓度范围内,随着颗粒浓度和光学厚度的增大,重建误差呈现了开始稍微减小然后又增大的趋势,重建温度场总体上能够较好的再现假设温度场的特征。

TDLAS技术用于燃烧场气体温度和浓度重建研究

基于可调谐半导体激光吸收光谱(Tunable Diode Laser Absorption Spectroscopy,TDLAS)技术及修正型代数迭代算法(Algebraic Reconstruction Technique,ART),选择频率为7 153.7 cm^(-1)和7 154.3 cm^(-1)的H_2O吸收线作为测温谱线,测量了CH_4/Air预混平面火焰炉燃烧场温度和H_2O气浓度分布。仿真采用1 000 pixels×1 000 pixels个像素点描述方形模型区域,假设40条光束从两个方向正交通过重建区域,通过引入初始分布并经修正型ART算法计算和三次多项式插值处理,温度场重建偏差在4.5%以内,H_2O气浓度场重建偏差在4%以内。实验采用导轨和转台实现探测光对稳态燃烧场两个方向上的平行扫描,共获取24路光束吸收信号,经修正型ART算法重建和三次多项式插值处理得到整个火焰炉燃烧区域的温度场和H_2O气浓度场分布。将温度场重建结果与热电偶的测量结果进行对比,表明该方法能够有效实现燃烧场温度二维重建。