Automatic modulation recognition of radiation source signals based on two-dimensional data matrix and improved residual neural network

Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the AMR method of radiation source signals based on two-dimensional data matrix and improved residual neural network is proposed in this paper.First,the time series of the radiation source signals are reconstructed into two-dimensional data matrix,which greatly simplifies the signal preprocessing process.Second,the depthwise convolution and large-size convolutional kernels based residual neural network(DLRNet)is proposed to improve the feature extraction capability of the AMR model.Finally,the model performs feature extraction and classification on the two-dimensional data matrix to obtain the recognition vector that represents the signal modulation type.Theoretical analysis and simulation results show that the AMR method based on two-dimensional data matrix and improved residual network can significantly improve the accuracy of the AMR method.The recognition accuracy of the proposed method maintains a high level greater than 90% even at -14 dB SNR.

Combinational therapy with Myc decoy oligodeoxynucleotides encapsulated in nanocarrier and X-irradiation on breast cancer cells

The Myc gene is the essential oncogene in triple-negative breast cancer(TNBC).This study investigates the synergistic effects of combining Myc decoy oligodeoxynucleotides-encapsulated niosomes-selenium hybrid nanocarriers with X-irradiation exposure on the MDA-MB-468 cell line.Decoy and scramble ODNs for Myc transcription factor were designed and synthesized based on promoter sequences of the Bcl2 gene.The nanocarriers were synthesized by loading Myc ODNs and selenium into chitosan(Chi-Se-DEC),which was then encapsulated in niosome-nanocarriers(NISM@Chi-Se-DEC).FT-IR,DLS,FESEM,and hemolysis tests were applied to confirm its characterization and physicochemical properties.Moreover,cellular uptake,cellular toxicity,apoptosis,cell cycle,and scratch repair assays were performed to evaluate its anticancer effects on cancer cells.All anticancer assessments were repeated under X-ray irradiation conditions(fractionated 2Gy).Physicochemical characteristics of niosomes containing SeNPs and ODNs showed that it is synthesized appropriately.It revealed that the anticancer effect of NISM@Chi-Se-DEC can be significantly improved in combination with X-ray irradiation treatment.It can be concluded that NISM@Chi-Se-DEC nanocarriers have the potential as a therapeutic agent for cancer treatment,particularly in combination with radiation therapy and in-vivo experiments are necessary to confirm the efficacy of this nano-drug.

On-Line Measurement of Ion Density in Atmospheric Nitrogen Discharge Filaments via Radiation Signals from Plasma Oscillation

Diagnosis of the particle number density of plasma plays an important role in the understanding of plasma sources and processing.Regular radiation signals from plasma oscillation in filaments of atmospheric nitrogen discharge,which were excited by the injection of secondary electron beams during the propagation of the streamer,are employed to determine the ion density of plasma and its evolution in the filaments.Results show that the density of N4＋ in a filament of atmospheric nitrogen discharge is of the order of 1013 cm-3.It is also found that the recombination processes play a dominant role in plasma decay,and that the ion density decreases non-monotonically with time during streamer propagation.

Role of PLC-PIP2 and cAMP-PKA Signal Pathways in Radiation-induced Immune-suppressing Effect

Objective The purpose of the present study was to observe the changes in CD4＋CD25＋Nrpl＋Treg cells after irradiation with different doses and explore the possible molecular mechanisms involved. Methods ICR mice and mouse lymphoma cell line （EL-4 cells） was used. The expressions of CD4, CD25, Nrpl, calcineurin and PKC-α were detected by flow cytometry. The expressions of TGF-131, IL-10, PKA and cAMP were estimated with ELISA. Results At 12 h after irradiation, the expression of Nrpl increased significantly in 4.0 Gy group, compared with sham-irradiation group （P〈0.05） in the spleen and thymus, respectively, when ICR mice received whole-body irradiation （WBI）. Meanwhile the synthesis of Interleukin 10 （IL-20） and transforming growth factor-β1 （TGF-β1） increased significantly after high dose irradiation （HDR） （〉 or = 1.0 Gy）. In addition, the expression of cAMP and PKA protein increased, while PKC-α, calcineurin decreased at 12h in thymus cells after 4.0 Gy X-irradiation. While TGF-β1 was clearly inhibited when the PLC-PIP2 signal pathway was stimulated or the cAMP-PKA signal pathway was blocked after 4.0 Gy X-irradiation, this did not limit the up-regulation of CD4＋CD25＋Nrpl＋Treg cells after ionizing radiation. Conclusion These results indicated that HDR might induce CD4＋CD25＋Nrpl＋Treg cells production and stimulate TGF-β1 secretion by regulating signal molecules in mice.

A theoretical study of the signal enhancement mechanism of coaxial DP-LIBS

In the field of dual-pulse laser-induced breakdown spectroscopy(DP-LIBS)research,the pursuit of methods for determining pulse intervals and other parameters quickly and conveniently in order to achieve optimal spectral signal enhancement is paramount.To aid researchers in identification of optimal signal enhancement conditions and more accurate interpretation of the underlying signal enhancement mechanisms,theoretical simulations of the spatiotemporal processes of coaxial DP-LIBS-induced plasma have been established in this work.Using a model based on laser ablation and two-dimensional axisymmetric fluid dynamics,plasma evolutions during aluminum–magnesium alloy laser ablation under single-pulse and coaxial dualpulse excitations have been simulated.The influences of factors,such as delay time,laser fluence,plasma temperature,and particle number density,on the DP-LIBS spectral signals are investigated.Under pulse intervals ranging from 50 to 1500 ns,the time evolutions of spectral line intensity,dual-pulse emission enhancement relative to the single-pulse results,laser irradiance,spatial distribution of plasma temperature and species number density,as well as laser irradiance shielded by plasma have been obtained.The study indicates that the main reason behind the radiation signal enhancement in coaxial DP-LIBS-induced plasma is attributed to the increased species number density and plasma temperature caused by the second laser,and it is inferred that the shielding effect of the plasma mainly occurs in the boundary layer of the stagnation point flow over the target surface.This research provides a theoretical basis for experimental research,parameter optimization,and signal enhancement tracing in DP-LIBS.

A hybrid decomposition-boosting model for short-term multi-step solar radiation forecasting with NARX neural network

Due to global energy depletion,solar energy technology has been widely used in the world.The output power of the solar energy systems is affected by solar radiation.Accurate short-term forecasting of solar radiation can ensure the safety of photovoltaic grids and improve the utilization efficiency of the solar energy systems.In the study,a new decomposition-boosting model using artificial intelligence is proposed to realize the solar radiation multi-step prediction.The proposed model includes four parts:signal decomposition(EWT),neural network(NARX),Adaboost and ARIMA.Three real solar radiation datasets from Changde,China were used to validate the efficiency of the proposed model.To verify the robustness of the multi-step prediction model,this experiment compared nine models and made 1,3,and 5 steps ahead predictions for the time series.It is verified that the proposed model has the best performance among all models.

Experimental study of ultralong wave band for electro－magnetic signals and acoustic emission during rock fracture

The electro-magnetic (EM) and acoustic emission (AE) in the fracture process of both dry and wet rock samples including gabbro, granite, sandstone and marble are studied in the experiment in the laboratory under uniaxial pressure. Signals during the test are detected in ultralow frequency band. The experimental results may be outlined as follows: original waveforms of the electro-magnetic radiation (EMR) and AE in the range of 0-20 kHz frequencies are obtained; the EMR's intensity in fracture process is related to some factors as rock type, content of water, fracture intensity of rocks, loading rates and fracture state etc.; the EMR'S rate is proportional to that of AE during fracture statistically. About 70% of maximum values of EMR rate and AE rate are corresponded with each other; furthermore, the EM signals (EMS) are generally more developed and longer duration than AE signals; the principal energy of EMS detected by copper coin antenna as sensor in power spectra are distributed in frequencies lower than 6 kHz and otherwise those detected by EMinduction coil are at about 10 kHz, and in contrast the major energies of AE are in frequencies less than3 kHz; another notable phenomenon is that distinct electro-magnetic signals are detected before AE occurrence. Since EMR and AE signals obtained in the process of rock fracture are better corresponded to eachother, therefore it'S reasonable to propose that the EMR anormalies observed prior to some earthquakes aremainly produced by fractures of rock in source region, as for the EMS occurred before AE may be related topiezoelectric and piezomagnetic effects.

Radiation and androgen withdrawal alter expression of apoptosis pathway genes of prostate cancer cells

Aim: To investigate the altered expression of apoptosis pathway genes of prostate cancer cells treated by radiation and androgen withdrawal and whether the combined treatment may induce additive apoptosis. Methods: Androgen sensitive prostate cancer cell line LNCaP was cultured and treated by radiation, androgen withdrawal and combination of the two. Apoptosis was determined using apoptotic cells staining and mononuclear cell direct cytotox-icity assay. The total RNA were extracted and harvested. cDNA probes were prepared and labeled with biotin-16-dUTP and then hybridized to commercially available cDNA arrays, including apoptosis pathway-specific genes. The expression of important gene was further determined using RT-PCR. Results: Radiation induced additive apoptosis of prostate cancer cells; androgen withdrawal exhibited synergetic action. TNFRSF8 variant 2, DFFA, LTbR, mdm2, Myd88, TNFRSF14 and TNFSF4 mRNA were up regulated by radiation, while Survivin and Bar mRNA were down regulated. Mcl-1, TNFRSF14, MyD88 and TNFSF4 mRNA were up regulated by androgen withdrawal, while Bar, Survivin and TRAIL-R3 mRNA were down regulated. Conclusion: Radiation and androgen withdrawal altered the expression of apoptosis pathway genes of prostate cancer cells in different patterns, which may contribute to the additive apoptotic effect induced by the combined treatment.

同步辐射装置主信号源的扩展方法研究

主信号源是同步辐射装置的关键组成部分之一,它不仅用于产生同步辐射光源各子系统所需的稳定度极高的参考信号,还用于生成整个装置的控制系统所需的高精度工作时钟。一般使用射频信号源作为主信号源,而商业射频信号源一般只配备单输出通道,远远不能满足同步辐射装置的需要,使用传统功分器对主信号通道进行扩展又存在幅度衰减、精度下降且相位不一致的问题。为解决上述问题,利用射频芯片AD9361,研究了对主信号源的单路输出进行扩展的方法。该方法可根据用户需求完成相应数量的信号通道扩展,设计了AD9361芯片和FPGA主控模块相结合的硬件架构。搭建实验平台,开展了射频信号源在C波段扩展的实验研究,对所提出的扩展方法进行实验验证。实验结果表明,该方法能保证扩展信号的幅度、频率与相位与主信号保持高度一致。

红外偏振辐射模型对铬和铜元素的优化识别

针对优化激光诱导击穿光谱技术识别铬和铜元素的问题,本文提出了一种结合红外偏振检测理论的方法。利用菲涅尔反射定律和基尔霍夫理论分析了红外偏振产生机理,根据能量守恒定律验证了目标红外自发热辐射的偏振特性;利用红外偏振辐射传输模型及菲涅尔反射穆勒矩阵,结合温度的麦克斯韦-玻尔兹曼分布特性,推导出了等离子体红外偏振辐射信号模型,用于识别各激发能量下的重金属元素;利用5种不同能量的脉冲激光验证了模型的精准性。结果表明:在相同的激光能量下,红外偏振辐射光谱可以收集到更多的特征信号峰;在低能量激励下,红外偏振辐射光谱的优势更为突出。红外偏振辐射模型的构建是科学有效的,可用于优化重金属元素的快速检测。

基于卡尔曼滤波的室内二次辐射噪声测量修正方法

地铁运营诱发的沿线建筑物二次辐射噪声已成为城市噪声投诉重要来源,大量的轨道减振措施因而得以应用。但是由于测试条件的原因,对减振轨道区间沿线的建筑物二次辐射噪声进行测试所获取的噪声信号往往与背景噪声信号差异较小,致使室内二次辐射噪声评估结果不稳定。为评估观测信号与背景噪声信号接近时的室内二次辐射噪声,提出一种基于卡尔曼滤波方法的楼板振动与室内噪声测试数据联合评估方法。首先,根据卡尔曼滤波器工作原理,提出室内观测噪声误差矩阵和经验公式预测方法误差矩阵的构造方法。而后采用向典型信号中掺入高斯白噪声的方法结合现场实测数据验证了该方法的可行性。最后基于该方法对比分析几种经验预测公式的效果。

低对比剂摄入量能谱肺动脉成像虚拟平扫代替胸部平扫的可行性

目的 探讨能谱CT虚拟平扫技术在肺动脉成像(CTPA)中代替胸部平扫降低患者辐射剂量的可行性。资料与方法 前瞻性收集2022年2—11月于大连医科大学附属第一医院行CTPA检查的56例患者,均接受常规胸部平扫及能谱CTPA增强扫描。分别测量胸部平扫和虚拟平扫图像上胸主动脉、肺动脉主干、竖脊肌及肺尖层面、气管隆嵴层面、肺底层面的肺实质CT值及噪声,并计算胸主动脉、肺动脉信噪比、对比噪声比。对两组图像质量及碘残留进行主观评价,并检验主观评分的一致性。记录患者剂量长度乘积、CT容积剂量指数及对比剂用量。比较胸部平扫和虚拟平扫图像各感兴趣区CT值、信噪比、对比噪声比、辐射剂量和主观评分。结果 2名医师的主观评分一致性较好(Kappa=0.984~0.992,P<0.05),胸部平扫、虚拟平扫图像主观评分分别为(4.75±0.65)分、(4.65±0.49)分,差异无统计学意义(t=0.630,P=0.437)。胸部平扫与虚拟平扫图像胸主动脉、肺动脉、各区域肺组织CT值差异无统计学意义(P>0.05);肺动脉及胸主动脉信噪比、对比噪声比差异无统计学意义(P>0.05)。用CTPA的虚拟平扫代替常规胸部平扫,患者辐射剂量由(7.27±1.74)mSv减少至(3.26±0.84)mSv,减少约55%。结论 CTPA虚拟平扫可代替胸部常规CT平扫用于肺部疾病筛查,大幅降低患者的辐射剂量。

沙参麦冬汤干预小细胞肺癌患者放射性肺损伤的作用与机制

目的探讨小细胞肺癌(small cell lung cancer,SCLC)合并放射性肺损伤患者应用沙参麦冬汤疗法对其血清转化生长因子-β(transforming growth factor-β,TGF-β)/Smad信号通路相关因子的影响及作用机制。方法选取接受放射治疗的104例SCLC合并放射性肺损伤患者,采用随机数字表法分为沙参麦冬汤干预组及常规治疗组,每组52例。常规治疗组予以常规西药治疗,沙参麦冬汤干预组在常规治疗组治疗的基础上加用沙参麦冬汤剂。观察2组的临床疗效,对比2组患者治疗前后的TGF-β、肿瘤坏死因子-α(tumor necrosis factor,TNF-α)和白细胞介素-6(interleukin-6,IL-6)水平,对比2组治疗前后身体机能状态量表(karnofsky performance scale,KPS)评分和临床-影像-生理(clinical-radiologicand physiological scale,CRP)评分,分析SCLC合并放射性肺损伤患者CRP评分与KPS评分的相关性。结果沙参麦冬汤干预组的临床治疗总有效率较常规治疗组明显升高(P<0.05);治疗后,2组血清TGF-β、TNF-α和IL-6水平均明显降低,且沙参麦冬汤干预组各指标较常规治疗组均明显降低(均P<0.05);2组KPS评分均明显升高,且沙参麦冬汤干预组高于常规治疗组(P<0.05);2组CRP评分均明显降低,且沙参麦冬汤干预组较常规治疗组明显降低(P<0.05);Pearson相关系数分析结果显示,SCLC合并放射性肺损伤患者CRP评分与KPS评分呈明显负相关(P<0.05)。结论沙参麦冬汤干预疗法对改善SCLC患者放射性肺损伤疗效显著,有助于降低患者血清TGF-β、TNF-α和IL-6水平,对抑制机体炎性反应、改善患者生活质量等具有积极作用。

基于PTEN与JAK对PI3K/Akt信号通路的影响探讨加味小蓟饮子治疗急性放射性膀胱炎的作用机制

目的:探讨加味小蓟饮子治疗急性放射性膀胱炎的作用机制。方法:50只ICR小鼠随机分为空白组12只和造模组38只。采用X射线辐照仪造模,造模后随机取2只小鼠处死鉴定模型是否成功。将剩余造模组小鼠随机分为模型组、小蓟饮子组和加味小蓟饮子组各12只。空白组、模型组、小蓟饮子组、加味小蓟饮子组分别予0.9%氯化钠、0.9%氯化钠、小蓟饮子药液,加味小蓟饮子药液灌胃处理,每日1次,连续7 d。末次灌胃后24 h处死取材,酶联免疫吸附实验(ELISA)法检测血清超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)、总抗氧化能力(T-AOC)含量。Western Blot法检测小鼠膀胱丝氨酸/苏氨酸激酶(AKT)、E钙粘着蛋白(E-Cadherin)、内皮素-1(ET-1)、JAK激酶(JAK)、核转录因子红系2相关因子2(Nrf2)、磷脂酰肌醇3-激酶(PI3K)、人第10号染色体缺失的磷酸酶(PTEN)、Smad蛋白2(Smad2)、Smad蛋白3(Smad3)、转化生长因子β1(TGF-β1)、尿斑蛋白3(Upk3)、血管内皮生长因子(VEGF)蛋白相对表达水平;实时荧光免疫定量-聚合酶链式反应法(RT-PCR)法检测小鼠膀胱微RNA-21(MicroRNA-21,miR-21)、PTEN、JAK、PI3K、AKT、Nrf2信使核糖核酸(mRNA)相对表达水平。结果:相较模型组,加味小蓟饮子组小鼠体内SOD、GSH-Px、T-AOC、AKT、E-Cadherin、JAK、Nrf2、PI3K、Upk3含量升高(P<0.05),MDA、ET-1、PTEN、Smad2、Smad3、TGF-β1、VEGF含量下降(P<0.05);与模型组和小蓟饮子组比较,加味小蓟饮子miR-21 mRNA表达升高(P<0.05)。结论:加味小蓟饮子组可能通过上调miR-21表达,同调PTEN、JAK蛋白以激活下游PI3K/AKT/Nrf2信号通路治疗急性放射性膀胱炎。

基于线性调频连续波的合作式通信辐射源测距

针对加速运动目标参数估计中,离散多项式变换方法无法进行非整数估计的问题,本文提出基于瑞夫算法的离散多项式变换法和基于Chirp-Z变换的离散多项式变换法2种新型离散多项式变换算法,对加速运动目标速度和加速度进行估计,并对2种算法的估计误差和计算量进行了分析比较。结果表明:2种算法在信噪比-20 dB时均方误差开始接近克拉美罗界。基于瑞夫算法的离散多项式变换法与3次迭代基于Chirp-Z变换的离散多项式变换法均可在较低信噪比下可实现任意频率的有效估计且性能接近,二者均可实现低信噪比下速度、加速度的有效估计,但基于瑞夫算法的离散多项式变换法计算量远小于3次迭代基于Chirp-Z变换的离散多项式变换法。

低成本接收阵列方向图测试系统与方法

采用传统的相控阵测试方法对数字阵列及数字波束合成进行测试,存在系统复杂、设备齐套周期长、问题难解耦等弊端。因此,对于数字阵列及相关算法,需要一种不依赖天线和物理环境,且能够以低成本和高效率,在系统开发中期完成相关性能评估和迭代的方法。给出一种基于阵列信号模拟技术的低成本接收阵列方向图测试系统,并提出了随机虚拟相移技术用于解决测试精度不足的问题。基于简要的理论分析、给出了测试平台构成和测试流程,并通过仿真和实测验证了方法的有效性。

甘草甜素调节TGF-β/Smad信号通路对肺癌荷瘤小鼠放射性肺损伤的影响

目的 研究甘草甜素(GL)是否可以通过调节TGF-β/Smad信号通路对肺癌荷瘤小鼠放射性肺损伤(RILI)产生影响。方法 取48只小鼠,先随机选出12只小鼠作为NC组,其余小鼠构建肺癌荷瘤小鼠模型并采用X射线照射全胸建立RILI模型,再将小鼠随机分为照射+Model组、照射+GL组(10 mg/kg)、照射+GL+SRI-011381组(10 mg/kg+30 mg/kg TGF-β激动剂)。使用酶联免疫吸附(ELISA)法检测小鼠血清中白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)的水平;HE染色法检测小鼠肺组织病理损伤;试剂盒检测小鼠肺组织中羟脯氨酸(HYP)、髓过氧化物酶(MPO)含量;免疫组化法(IHC)检测肺组织中TGF-β、α-SMA表达;Western Blot检测小鼠肺组织中TGF-β1、p-Smad2/3、Smad7蛋白表达。结果 与NC组比较,照射+Model组小鼠血清中IL-6、TNF-α水平、HYP、MPO、TGF-β和α-SMA表达、TGF-β1、p-Smad2/3蛋白表达升高,肺组织病理损伤加重,Smad7蛋白表达降低(P<0.05);与照射+Model组比较,照射+GL组小鼠血清中IL-6、TNF-α水平、HYP、MPO、TGF-β和α-SMA表达、TGF-β1、p-Smad2/3蛋白表达减少,肺组织病理损伤减轻,Smad7蛋白表达增加(P<0.05);照射+GL+SRI-011381组中实验检测结果则与照射+GL组结果趋势相反,表明SRI-011381干预后减弱了GL对肺癌荷瘤小鼠RILI的改善作用。结论 甘草甜素可以通过抑制TGF-β/Smad信号通路对肺癌荷瘤小鼠放射性肺损伤进行修护改善。

放射性心脏损伤相关信号通路及药物干预的研究进展

放射性心脏损伤(RIHD)是继发于胸部肿瘤放疗后的心脏毒性事件,已成为除癌细胞毒性外,影响癌症患者机体健康的又一不利因素。信号传导在细胞信息交流中发挥重要作用,RIHD可诱导信号通路失调,阻碍通路功能的正常发挥,从而引起心肌组织发生凋亡、氧化应激及纤维化等病变。现综述RIHD发生发展中失调的相关通路,以及药物干预对通路的调控作用,为防治RIHD提供参考依据。

基于谱估计的微振动测试与评估方法及其应用

随着第四代同步辐射光源对束流亮度和发射度的要求日益严苛,微振动对束流品质的影响逐渐凸显。然而,国际上尚无统一的标准来全面测试和评估地基微振动的影响,对微振动的有效管理和控制变得尤为困难。本文建立基于谱估计的振动数据处理模型,并提出基于概率统计的方法来评估地基微振动位移,全面客观地评价振动位移有效值。利用该模型对武汉先进光源预研基地的实验大厅进行振动对比测试、振源分析及振动位移评估,得出垂直方向的振动位移有效值的平均值(Average Root Mean Square,Ave RMS)为8.08 nm,标准偏差σ为4.55 nm,即垂直振动位移(Ave RMS+3σ)为21.73 nm,满足40 nm的设计要求。该振动数据处理方法不仅适用于初始地块与基础隔振处理后地基的振动评估,还适用于元部件级别的振源排查分析。

时间特征与空间特征融合的轻量网络故障诊断方法

为了解决多传感器数据间存在信息交叉、特征重复,导致模型训练精度低的问题,对滚动轴承在声辐射信号下的故障诊断进行了研究,提出了一种时间特征与空间特征融合的轻量网络故障诊断(SF-TFNet)方法。首先,利用卷积神经网络提取了原始轴承声阵列信号的空间特征(SFs),使用长短时记忆网络(LSTM)提取了声阵列信号中的时域特征(TFs),并对提取的SFs和TFs进行了特征融合,生成了新的特征矩阵;然后,为了消除融合特征带来的重叠特征和信息冗余问题,引入了基于核的主成分分析(KPCA)方法对新生成的特征矩阵进行了非线性降维,去除了特征中的冗余成分,构建了滚动轴承新的时空特征数据集;最后,采用AdaBoost算法对新生成的数据集进行了故障分类,并得到了滚动轴承的最终故障诊断结果。研究结果表明:在半消声室滚动轴承故障实验台测试中,SF-TFNet方法的故障分类精度可以达到99.75%,其分类精度较高、聚类效果明显。在强背景噪声环境下与ResNet、ICNN和AlexNet三种方法进行比较,SF-TFNet方法不仅收敛速度快,而且故障识别精度高,诊断精度最高可达99.25%。为基于多通道的滚动轴承声辐射信号故障诊断提供了理论依据。