尾焰的紫外高分辨辐射图像仿真与特征提取

基于改进的球谐离散坐标法建立了飞行器尾焰的紫外辐射亮度仿真模型。在尾焰羽流的热辐射基础上，重点考虑了尾焰中气体分子的化学荧光辐射源及由尾焰中三氧化二铝簇团粒子的平均光学特性带来的多重散射源效应。基于辐射传输方程，在球谐离散坐标系中，对尾焰在不同观测角度、不同介质分布的紫外辐射亮度进行了数值计算，实现了高分辨的三维尾焰辐射亮度的空间分布图像仿真。同时，采用灰度共生矩阵算法获得尾焰辐射亮度分级分布的灰度图，结合二维超分辨旋转不变子空间算法、α-shape方法和橡皮筋算法，提出了尾焰辐射中心位置和辐射亮度峰值轮廓曲线提取的新方法，得到了尾焰辐亮度特征的准确提取，为飞行器目标和尾焰的高分辨辐射图像特征识别提供了重要的参考依据和途径。     

卫星姿控推进器尾焰红外辐射的数值模拟

为全面了解卫星的红外辐射特性,需掌握卫星姿控推进器尾焰的红外辐射特性.按照先计算尾焰的流场、再计算尾焰的吸收系数、最后用有限体积法求解尾焰的红外辐射亮度的逻辑顺序,较完整地建立了卫星姿控推进器尾焰红外辐射的求解模型;根据该模型计算得到尾焰的辐射亮度,进一步求解获得了1000～4500cm-1内的光谱和波段辐射强度.通过...     

某喷气发动机尾焰的中长波红外辐射分析和比较

利用中波红外和长波红外热像仪对某型 喷气飞机发动机尾焰的红外辐射特性进行了测量,得到了3～5 μm 和8～12 μm波段的尾焰辐射亮度分布。结果表明,从飞机 尾向上观测到的中波红外和长波红外尾焰均成对称分布,前者的最高辐射亮 度和尾焰面积分别是后者的4.6倍和2.1倍;从飞机侧向上观测到的 中波红外尾焰的最高辐射亮度、尾焰长度和面积分别是长波红外尾焰 的2.2倍、3.8倍和5.7倍,前者的优势非常明显。另外,受高温尾焰加热的影响,尾 焰周围空气的温度明显上升,使其辐 射亮度高于其他背景的辐射亮度。本文获得的测量结果对尾焰红外辐射特性仿 真和计算研究具有一定的参考价值。     

导弹尾焰红外辐射运动变化探测研究

针对导弹尾焰红外辐射的探测问题,分析了导弹的运动状态对尾焰红外辐射探测的影响,建立了导弹尾焰红外辐射探测模型。主要研究了直线、水平圆弧及爬升和下滑的运动状态的探测模型,并进行了仿真,得出了三种运动状态下导弹尾焰红外辐射运动探测的变化规律。     

轨控推进器喷管对尾焰红外辐射的影响研究

针对关于卫星推进器尾焰的红外特性研究较少的现状,对某双组元轨控推进器尾焰的红外辐射进行数值模拟.采用贴体坐标系下的有限体积法,联合求解较复杂形状的喷管扩张段和尾焰的辐射传递方程,得到尾焰的光谱和3～5μm的波段辐射强度.为精确计算尾焰的红外辐射,全面评估了喷管扩张段的辐射对后端尾焰红外辐射的影响.通过对比分析,当天顶角θ＝7π/16时,距离喷口的位置越近,尾焰辐射受到扩张段的影响越剧烈;若扩张段内壁的发射率减小,尾焰在θ＝7π/16方向上的波段辐射强度则会变小;喷口近处的尾焰,在扩张段辐射影响下,计算得到的波段辐射强度数值远大于忽略扩张段的影响下得到的数值.得出结论:在考虑喷管扩张段辐射的影响下,能够很好地改善轨控推进器尾焰红外辐射的计算准确性.     

轨控推进器尾焰对太阳辐射吸收的研究

为掌握轨控推进器尾焰的吸收特性,研究了尾焰对太阳红外辐射的吸收问题.在贴体坐标系下,运用有限体积法,建立了尾焰对太阳红外辐射的吸收模型.经过求解,获得受到尾焰吸收后、在尾焰边界处的太阳光谱辐射亮度.比较吸收前和吸收后太阳的光谱辐射亮度,发现,当喷口距离等于0.483 m时,在波数1700 cm-1、2155 cm-1、...     

尾焰红外辐射特性的反向蒙特卡罗法模拟

以发动机尾焰的红外探测为主要应用背景,利用反向蒙特卡罗法计算了液体火箭发动机尾焰红外辐射特性。首先计算了尾焰红外辐射在2.7μm下的轴向分布特性及空间不同角度分布特性,计算结果较为合理。重点计算了尾焰2~5μm的光谱辐射特性,并考虑了大气衰减的影响,与TheAerodyne Radiation Code的计算结果趋势吻合良好。实际探测时,探测器只能接收到尾焰辐射的小部分能量,因此对一定距离下探测器接收辐射进行计算,进而获得尾焰在探测器视场内的红外光谱辐射分布特性,具有重要的理论意义和实际应用前景。     

高速飞行目标尾焰红外辐射特性的建模仿真计算

飞行器目标的尾焰红外辐射特性对目标的红外探测、识别和跟踪具有极其重要的作用。为了分析尾焰的红外辐射特性,首先根据经验公式计算出尾焰的流场分布,然后使用窄带模型计算出谱带的光谱吸收系数和透过率;对于非均匀热气体,考虑到碰撞展宽效应和多普勒展宽效应,使用C-G谱带传输模型得到飞行器尾焰2~5 μm的红外辐射分布。最后, 计算了不同组分的尾焰红外辐射特性,分析了组分分布和大气传输对尾焰红外辐射特性的影响,为探测波段的选择提供了参考依据。     

基于窄谱带模型的尾焰红外辐射计算

尾焰红外辐射的计算是飞行器红外辐射计算的重要环节.在尾焰流场工程计算模型的基础上,从燃烧的化学反应出发,解决了尾喷口处气体组分参数的计算问题,利用基于Malkmus窄谱带模型的C-G近似法得到了尾焰红外辐射的快速计算方法.仿真结果表明,该方法能够快速准确地计算出尾焰的辐射,能为红外制导导弹仿真中飞机目标红外辐射的计算提供有效途径.     

直升机排气系统尾焰红外辐射数值计算研究

尾焰是直升机红外辐射的主要来源之一。通过将直升机尾焰流场模型、气体辐射指数宽谱带模型(EWBM)和辐射传输方程(RTE)相结合,发展了一种直升机尾焰红外辐射特性估算方法。通过2个算例从不同的角度对该方法进行了验证,结果表明:采用该方法对尾焰红外辐射进行计算与分析是可行的,能满足工程设计的需要。     

Release of active forms of oxygen by blood neutrophils of Syrian hamsters with primary and transplanted tumors

The production of reactive oxygen forms by the blood neutrophils of Syrian hamsters bearing primary or transplantable tumours has been studied by chemiluminescence test. It is demonstrated that at the early developmental stages of spontaneous primary lymphosarcomas, or of certain malignant transplantable tumours of different origin there is a significant decrease in the spontaneous chemiluminescence and an increase in phagocytosis-dependent chemiluminescence of blood neutrophils. Such a decrease in the spontaneous chemiluminescence was not observed in hamsters bearing tumours with the low metastatic activity as well as in animals with abscesses.     

Optical cavity structure design and optical path simulation for rapid nitric oxide detection

According to the chemiluminescence reaction mechanism of nitric oxide (NO) and ozone (O3), a new cylindrical total reflection S-type optical cavity design for rapid detection of NO gas is proposed. The optical cavity model is based on the total reflection S-type structure on the inner wall of the cylinder. Optical software ZEMAX was used to simulate the optical path of the model, and software FLUENT was used to simulate and verify the structure. The comparative analysis showed that the chemiluminescence collection efficiency of the S-type optical cavity collection path was 36.6%, and the gas reaction and mixing in the S-type optical cavity model was more sufficient, and the reaction mixing stability error was 0.049, which was 2 times higher than the traditional stability error. The model is simple in structure and meets the new national standards. It provides a practical idea of design for the real-time exhaust gas detection.     

NH_3-O_2体系单脉冲CO_2激光复相爆燃反应研究

研究了以TEA CO_2单脉冲激光辐照在Pt-Rh(10％)等金属表面上引发的NH_3 O_2复相爆燃反应。Pt-Rh等表面的存在明显地降低了引爆反应所需的激光功率密度。该反应的引爆阈值与激光的频率、不同的金属表面和处理方法、以及NH_3 O_2混合气体的总压力和分压比都有关。此外,还测定了该爆燃反应所产生的化学发光光谱,并讨论了反应机理。     

活性氮与三溴甲烷反应化学发光研究

在流动余辉装置上,利用空心阴极放电产生的活性氮与CHBr3分子碰撞,在550～750 nm波长范围内观察到了较强的NBr(b→X)跃迁发射谱;同时,在反应管的下游,我们探测到了CN(A,B)的发射谱.分析认为化学发光机理是:亚稳态氮原子N(2D)与CHBr3之间的一步传能反应直接产生了NBr(b)激发态,而CN(A,B)态则来自基态原子N(4S)与CBr的反应,其中CBr是CHBr3经活性氮中的亚稳态N2(A)激发离解形成的.     

化学发光法在绿原酸分析中的应用

本文重点讨论了化学发光分析法在绿原酸分析中的应用.     

Catalytic Performance of Nanoscale‐Corrugated Gold and Silver Films for Surface‐Enhanced Chemiluminescence

Biochips of corrugated gold and silver displaying surface plasmon resonance at different energies are fabricated to determine the nature of the mechanism responsible for the surface‐enhanced chemiluminescence (SECL) of luminol. This Full Paper proves that, whereas silver possesses the strongest resonance and the greatest plasmon overlap with luminol emission, silver is also the metal that induces the lowest CL enhancement (two orders of magnitude less than gold). Therefore, the enhancement mechanism is not related to plasmon‐assisted processes but rather originates from catalytic properties induced by corrugation of the metal film.     

基于Lab Windows/CVI的硫氮分析仪的研制

主要介绍了一种集紫外荧光法和化学发光法于一体的新型硫氮分析仪,系统采用模块化设计,数据的采集是在LabWindows/CVI的环境下,通过C8051F040完成的.介绍了系统的工作原理,以及硫氮分析仪的硬件接口电路设计,最后介绍了基于Lab Windows/CVI的用户界面设计,以及应用校准法得到硫氮浓度的计算方法.本系统测量速度快,结果精确,应用范围比较广泛,尤其是对低含量硫氮的分析精度比较高,检测下限可达到0.1 mg/L.本系统对于硫氮含量的测定有重要意义,对于同类系统的研发有参考价值.     

Near‐Infrared Chemiluminescent Reporters for In Vivo Imaging of Reactive Oxygen and Nitrogen Species in Kidneys

Despite the superior sensitivity of chemiluminescence over fluorescence, most chemiluminescence reporters only emit visible light, and have low water solubility, making them poorly equipped for in vivo imaging applications. Herein two near‐infrared (NIR) chemiluminescent reporters (NCRs) with high renal clearance for real‐time imaging of reactive oxygen and nitrogen species in the kidneys are synthesized. NCRs comprise a β‐cyclodextrin unit and a modified dicyanomethylene‐4H‐pyran containing Schaap's dioxetane as the renal‐clearance enabler and the chemiluminescent moiety, respectively. NCR1 and NCR2 specifically activate their NIR chemiluminescence towards superoxide anion (O₂^??) and peroxynitrite (ONOO^?), respectively. By virtue of their nanomolar sensitivity and high renal clearance, NCRs not only detect subtle upregulation of endogenous RONS in cells but also enable noninvasive monitoring of RONS in the kidneys under nephrotoxic exposure. The earlier activation of NCR1 relative to NCR2 implies the sequential upregulation of O₂^?? and ONOO^? during drug‐induced acute kidney injury (AKI). Moreover, detection of the fluorescence of excreted NCRs permits urinalysis of AKI, detecting the upregulation of RONS at least 24 h earlier than histological analysis. Thus, this study not only introduces ultrasensitive NIR chemiluminescent probes but also provides guidelines to transform them into legitimate imaging agents for organ‐specific in vivo detection.     

The mutagenic action of the dust of natural zeolites and chrysotile asbestos

The cell chemiluminescence method was used to demonstrate the ability of asbest and zeolite dusts from 8 deposits of the USSR to induce generation of free oxygen radicals in the phagocytosing cells suspension. It has been found that asbest and zeolite (0.01 and 0.05 mg/ml) increase levels of cells with chromosome aberrations in human cell cultures. The cytogenetic effect of asbest was inhibited by superoxide dismutase (50 mg/ml). The damaging effect of zeolite was decreased by the pharmacological drug bemithyl (0.007-0.07 mM) and completely eliminated by catalase (20 mg/ml). The results obtained indicate that mutagenic effect of dust particles of asbest and zeolite is mediated by oxygen radicals.     

Recent Advances on Black Phosphorus for Biomedicine and Biosensing

Black phosphorus nanostructures (nano‐BPs) include BP nanosheets, BP quantum dots, and BP nanoparticles. Since first being discovered in 2014, nano‐BP has become one of the most popular nanomaterials. Nano‐BP has many unique properties, such as excellent surface activity, tunable bandgap, high carrier mobility, moderate on/off ratio, excellent biocompatibility, good biodegradation, etc., all of which make nano‐BP particularly attractive in biomedicine and biosensing. This review article comprehensively summarizes recent advances in synthesis, functionalization, biomedicine, and biosensing applications of nano‐BP. Different methods are first introduced, such as mechanical cleavage, liquid‐phase ultrasonic exfoliation, electrochemical exfoliation, solvothermal treatment, and acoustic‐microfluidic stripping, for making the nano‐BP. Then two strategies are emphasized to enhance ambient stability of nano‐BP, namely physical encapsulation and chemical modification. Next, how to develop nano‐BP as advanced imaging agents, nanocarriers, and nanomedicine for bioimaging (fluorescence imaging, thermal imaging, and photoacoustic imaging) and disease treatment (phototherapy and photo/chemical/immune synergistic therapy) is demonstrated. The biosensing applications on nano‐BP is introduced, including electrochemical biosensor, fluorescence biosensor, chemiluminescence biosensor, electrogenerated chemiluminescence biosensor, and colorimetric biosensor. Finally, the current challenges and future perspectives on nano‐BP in bioapplications are discussed.