首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
We present the results of modeling the action spectrum and an experimental investigation of the effect of laser-induced photodissociation of oxyhemoglobin in vivo on the increase in the degree of oxygenation of skin tissue in the exposed area. We have shown that controlling the local concentration of free molecular oxygen in biological tissues together with the possibility of eliminating tissue hypoxia using laser radiation makes it possible to stimulate aerobic cell metabolism and to achieve the needed therapeutic effect. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 120–125, January–February, 2007.  相似文献   

2.
We propose a method for dosimetry of the biological response to laser irradiation based on determination of the amount of oxygen additionally supplied to the tissue. We show that it is feasible to determine the therapeutic dose from the change in the degree of oxygen saturation of the blood, heart rate, hemoglobin concentration in the blood, and exposure time. __________ 13Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 516–520, July–August, 2006.  相似文献   

3.
The action spectra of the complex of hemoglobin (Hb) with the ligand CO in cutaneous blood vessels have been determined. It is proposed to use the photodissociation of the HbCO complex for elimination of the poisoning action of the CO gas. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 3, pp. 422–424, May–June, 2005.  相似文献   

4.
本文的基本思想是设计双层金铝薄膜靶以检测激光脉冲宽度与等离子体消融深度的关系,找出有效的等离子体加热方法以产生更强更亮的等离子体辐射源.由于有预脉冲激光的存在,表层金薄膜首先被消融,由主脉冲携带的大能量就能较易穿过表层金等离子体将能量聚焦在内层铝靶上,由此产生内层高温等离子体.又由于外层低温等离子体存在,其将有效的阻碍内高温等离子体因膨胀而引起的能量损失.对无预脉冲而言,直接入射激光能量都沉积在靶表层形成表层高温等离子体.但是激光直接入射而产生的等离子体辐射总强度只比由预脉冲情况下产生的金等离子体辐射强度增加15%.而预脉冲能量只占激光总能量的2%.实验结果显示Al光谱线主要来自类氢,类氦离子跃迁.Au等离子体光谱线主要来自它的N带,O带和P带谱.我们也观察到一个明显的软X射线短波发射极限.所有结果显示由于预脉冲的存在将对靶各层等离子体辐射产生极大的影响  相似文献   

5.
An optimizing Dynamic Spectrum method based on short-time Fourier transform for noninvasive hemoglobin measurement was proposed. A total of 187 volunteers’ spectral data and blood samples were prepared for the calibration (167 samples) and prediction (20 samples) sets. Data processing with optimizing dynamic spectrum method was set as experimental group, while control group was with classical method based on fast Fourier transform. The model for hemoglobin prediction was established with partial least square regression. In the experimental group, the average prediction correlation coefficient was 0.8399, while that of the control group was 0.6686. The results demonstrate that the optimizing method has a good accuracy improvement for noninvasive hemoglobin measurement. The optimizing dynamic spectrum method combining statistical characteristics analysis as a modified analytical method has a promising application prospect of application in noninvasive blood component measurement field.  相似文献   

6.
谢安东  周玲玲  阮文  伍冬兰  罗文浪 《物理学报》2012,61(4):43302-043302
在相对论有效原子实势近似下, 以Pu为SDD基组、O为6-311+G*基组, 采用优选的密度泛函 B3LYP方法, 研究了用电场摸拟钚本身产生自辐射场(-0.005—0.005 a.u.) 作用下氧化钚(PuO)基态分子的最高占据轨道(HOMO)能级EH、最低空轨道(LUMO)能级EL、能隙Eg和费米能级EF. 结果表明: 在所加的电场范围内, EH随着电场的增加均逐渐减少, EF随着电场的增加均逐渐增大, Eg始终处于增大的趋势, 费米能级EF上升, 占据轨道的电子难以被激发至空轨道而形成激发态, PuO分子在自辐射场中更趋于稳定, 可以阻止O2, H2等扩散到表面内层而腐蚀钚表面, 有利于了钚在自辐射场中抗腐蚀.  相似文献   

7.
1 INTROEXPERIMENTExperimentalsetupwasshowninFig .1,exhaustivedescriptionsonthesetupandtheprocessofacquiringdatahasalready giveninrelativedocument[1] ,nowwedoexcessivedescriptionnolonger .2 RESULTANDDISCUSSIONResult:earlierspectraoftheplasmaradiatingwereshow…  相似文献   

8.
以热辐射谱的温度反演为例,介绍了光谱技术在强激光毁伤过程中的应用。利用自制的高速光谱测量系统,实时采集了毁伤过程中的辐射光谱,基于普朗克黑体辐射原理,反演了毁伤区的温度,并应用主成分回归算法,计算得到了毁伤区的温度分布,实现了强激光辐照靶材过程中瞬态温度和温度分布的测量。光谱测量区在200~1 000 nm时,所对应的温度反演为700~6 000℃。  相似文献   

9.
1 INTRODUCTIONWithrapiddevelopmentoftheapplicationoflaser ,especiallyinmilitaryaffairs[1] ,moreandmorepeopleundertaketoresearchmutualeffectbetweenlaserbeamandmaterials ,deliveringmanyarticlesonthesubject[2 ,4 ] .Butmostofthemreportevolvinglawsoftheplasmasindu…  相似文献   

10.
在相对论有效原子实势(RECP)近似下,采用优选的密度泛函 B3P86方法,研究了钚本身产生自辐射场(-0.005~0.005a.u.)作用下PuO2基态分子的能隙Eg和谐振频率ν.结果表明:能隙Eg=3.157eV,接近实验值1.8eV,PuO2在自辐射场中具有半导体性质;反对称伸缩振动频率ν3(σg)、弯曲振动频率ν2(πu)和对称伸缩振动频率ν1(σg)与实验值794.3 cm-1、230.2、746.5cm-1基本吻合.  相似文献   

11.
铀原子和氧原子分别使用相对论有效原子实势(Relativistic Effective Core Potential)和6-311+G(d)基组,采用优选的密度泛函B3P86方法,研究了铀本身产生自辐射场(-0.005~0.005a.u.)作用下UO2基态分子的能隙Eg和谐振频率ν.结果表明:能隙Eg=2.0028eV、1.9974 eV,接近实验值2.1eV,UO2在自辐射场中具有半导体性质;反对称伸缩振动频率ν3(σg)、弯曲振动频率ν2(πu)和对称伸缩振动频率ν1(σg)与实验值776.1 cm-1、225.2 cm-1、765.4cm-1基本吻合.  相似文献   

12.
Forces exerted on a small transparent dielectric sphere in a Gaussian beam is an-alyzed.The stable position of the sphere in the Gaussian beam was calculated.The effects ofthe sphere size,the beam radius etc.on the exerted forces,on the equilibrium positions aswell as on other parameters of the sphere are discussed.  相似文献   

13.
In this paper, the mechanism of free electron laser with a guide magnetic field is investigated by analyzing spontaneous radiation spectrum of electrons. The physical relation between spontaneous radiation and stimulated radiation in FEL with a guide magnetic field is studied. It is found that this relation in FEL is similar to that in quantum lasers. The spontaneous radiation spectrum is discrete. The frequency of stimulated radiation in FEL is oneselected and amplified in the radiation spectrum.  相似文献   

14.
We have studied the ratio of the intensities of radiation scattered by a layer of blood in a cuvet and by the cuvet walls for normal incidence or incidence at the Brewster angle for probing radiation from a He-Ne laser, linearly polarized in the plane of incidence (plane of observation) or orthogonal to that plane. We have compared it with the intensity of the radiation reflected by the surface of the cuvet wall, as estimated based on the geometric approximation. We have found the optimal conditions for probing and observing scattering for the layer in a cuvet, where such conditions are characterized by a minimal effect from the cuvet walls and the maximum ratio of useful signal to background. Report given at the Fifth International Scientific and Technical Conference on Quantum Electronics, 22–25 November 2004, Minsk, Belarus. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 270–272, March–April, 2006.  相似文献   

15.
N Y Shaparev 《中国物理 B》2016,25(10):103203-103203
In this paper, we analyze the spectral behavior(optical thickness, shape and linewidth) of laser radiation absorption under the correlation heating of ions in an ultracold plasma. The Voigt formula is used to find the absorption coefficient.The spectral line width is shown to grow with time while the optical thickness reduces. Our modeling results are in good agreement with the experimental findings reported in the literature.  相似文献   

16.
We present the results of a spectral study of the effect of low-intensity laser radiation on the molecular structure of blood and blood components. Analysis of the Fourier transform IR absorption spectra of blood confirmed the changes we observed previously in the oxygen transport characteristics of blood with intravenous exposure to the emission from a He-Ne laser. We show that structural and conformational changes in the hemoglobin tetramer, initiated by laser-induced photoreactions between Hb and oxygen, lead to characteristic changes in the shape and intensity of the IR bands for NH stretching vibrations, and also the amide I and amide II absorption bands. In the IR spectra of irradiated blood samples, we note increased absorption in the bands for stretching vibrations of the phosphate groups (945–1280 cm−1), which is evidence for an increase in the nucleic acid content (DNA, RNA). In the spectra of plasma and erythrocytes prepared from irradiated blood, there are no changes in this region of the IR spectrum. At the same time, in the IR spectra of samples of irradiated plasma, the intensity of the bands for stretching vibrations of the CH2 groups increases substantially. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 106–112, January–February, 2006.  相似文献   

17.
谢安东  谢晶  周玲玲  伍冬兰  阮文  罗文浪 《物理学报》2015,64(6):63301-063301
对铀原子和氮原子分别使用相对论有效原子实势和6-311+G(d)基组, 采用优选的密度泛函B3P86方法, 研究了铀本身产生自辐射场(-0.005–0.005 a.u.)作用下UN2基态分子的能隙Eg和谐振频率ν. 结果表明: UN2分子在自辐射场中反对称伸缩振动频率ν3(σg)和对称伸缩振动频率σ1(σg)与实验值1051.1 cm-1和1008.3 cm-1 基本符合; Eg随自辐射场场强的增大而趋于减少, 占据轨道的电子容易被激发至空轨道而形成激发态; UN2分子在自辐射场中趋于不稳定, N2, O2等更容易扩散到表面内层而腐蚀铀表面, 加剧了铀在自辐射场中的腐蚀.  相似文献   

18.
基于Labview的激光多普勒测速仪的频谱校正   总被引:1,自引:0,他引:1       下载免费PDF全文
在激光多普勒测速仪中,为了减小由信号处理算法带来的测量误差,提出运用频谱校正算法对多普勒信号的频谱进行校正,详细阐述了能量重心法、比值法和相位差法3种离散频谱校正算法的基本原理,运用这3种算法对理想正弦信号进行仿真,并运用比值法对信号施加不同频率和信噪比的噪音下的正弦信号和实测的多普勒信号进行仿真及实验研究。结果表明:3种算法都可以使信号的频率更接近于真实值,其中能量重心法校正精度相对较低,比值法和相位差法精度较高,尤其是比值校正算法处理速度更快,校正的精度基本不受信噪比的影响。将比值法运用于激光多普勒测速系统,与光接收计数法测量结果进行比较,结果显示:校正后比较正前激光多普勒测速仪测量相对精度提高了2~3倍。  相似文献   

19.
在激光多普勒测速仪中,为了减小由信号处理算法带来的测量误差,提出运用频谱校正算法对多普勒信号的频谱进行校正,详细阐述了能量重心法、比值法和相位差法3种离散频谱校正算法的基本原理,运用这3种算法对理想正弦信号进行仿真,并运用比值法对信号施加不同频率和信噪比的噪音下的正弦信号和实测的多普勒信号进行仿真及实验研究。结果表明:3种算法都可以使信号的频率更接近于真实值,其中能量重心法校正精度相对较低,比值法和相位差法精度较高,尤其是比值校正算法处理速度更快,校正的精度基本不受信噪比的影响。将比值法运用于激光多普勒测速系统,与光接收计数法测量结果进行比较,结果显示:校正后比较正前激光多普勒测速仪测量相对精度提高了2~3倍。  相似文献   

20.
For laser internal therapy in medical applications, optical fibres are required to propagate the laser beam. The far-field pattern of the laser beam at the exit face of the optical fibre is studied using a multimode step-index fibre and a graded index Selfoc fibre. The degree of dispersion, or the output angular distribution, of the beam passing through the Selfoc fibre is much smaller than that passing through the multimode step-index fibre. Consequently, the energy density in the far-field pattern of the beam passing through the Selfoc fibre is very much larger than that for the beam passing through the multimode step-index fibre. It is concluded that the Selfoc fibre is more effective in laser internal therapy.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号