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1.
A new technique of Mueller-matrix mapping of the birefringent structure of biological preparations of human organs tissues is suggested. The algorithms of reconstruction of average values and magnitude of fluctuations of the phase (birefringence) and amplitude (dichroism) of optically anisotropic structure of myocardium and connective tissue component of the vaginal wall histological section are proposed. The magnitudes and ranges of changes in the statistical moments of the 1st-4th order that characterize the distribution of average values and magnitude of fluctuations of birefringence and dichroism of the myocardium and connective tissue of the vaginal tissues histological sections were determined. Joint studies of distributions of the characteristics of phase and amplitude of the anisotropy of myocardium and connective tissue component of the vaginal wall tissues of different states were performed. The cases of various necrotic changes in the myocardium and pathological conditions of the vagina wall (prolapse of the genitals) are examined. Balanced accuracy of the method of Mueller-matrix polarization-phase and diffuse tomography of optically anisotropic polycrystalline networks in the differentiation of necrotic and pathological changes in human organs is determined.  相似文献   

2.
Combination of several drugs is often necessary especially during long-term therapy. The competitive binding drugs can cause a decrease in the amount of drug bound to protein and increase the biological active fraction of the drug. The aim of this study is to analyze the interactions of Lomefloxacin (LMF) and Colchicine (COL) with human serum albumin (HSA) and to evaluate the mechanism of simultaneous binding of LMF and COL to protein. Fluorescence analysis was used to estimate the effect of drugs on the protein fluorescence and to define the binding and quenching properties of drugs-HSA complexes. The binding sites for LMF and COL were identified in tertiary structure of HSA with the use of spectrofluorescence analysis. The analysis of fluorescence quenching of HSA in the binary and ternary systems show that LMF does not affect the complex formed between COL and HSA. On the contrary, COL decreases the interaction between LMF and HSA. The results of synchronous fluorescence, resonance light scattering and circular dichroism spectra of binary and ternary systems show that binding of LMF and COL to HSA can induce micro-environmental and conformational changes in HSA. The simultaneous presence of LMF and COL in binding to HSA should be taken into account in the multi-drug therapy, and necessity of using a monitoring therapy owning to the possible increase of the uncontrolled toxic effects. Molecular modeling of the possible binding sites of LMF and COL in binary and ternary systems to HSA confirms the spectroscopic results.  相似文献   

3.
侏罗纪优质煤炭资源为煤制油、制气等清洁高效利用提供了丰富的物质基础,其显微组分以富集惰质组为特征,而镜质组与惰质组大分子结构在很大程度上决定了煤的物理化学性质和工艺性能,进而决定了煤炭资源的综合利用效率及附加值。采集并制备了陕北侏罗纪煤田小保当煤矿和柠条塔煤矿的原煤(XR)、富镜质组煤(XV、NV)和富惰质组煤(XI、NI)样品,利用傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、固体13C核磁共振谱(13C NMR)等手段,结合煤质分析结果,定量表征了不同显微组分富集物分子结构的差异。研究结果表明:XI和NI煤中芳烃结构芳环取代程度低,主要以3个相邻、4~5个相邻的氢原子形式存在,苯环上氢原子较少被其他官能团取代,同时其结构中芳烃C═C骨架振动明显,脂肪结构中亚甲基伸缩振动强度较低,并且甲基含量略高于富镜煤,C═O基团相对含量略高,表明富惰煤有较多含氧桥键相连的芳香结构,其结构中脂族链、脂环基团脱落、断裂以及芳烃富集,支链相对较少且长度较短,芳碳率、芳香度、芳环缩合程度及成熟度较高。XV和NV煤中表面结构中碳的赋存形态“C—C,C—H”,“C—O”的相对含量高于富惰煤,反映其结构中应含较多的芳环取代的脂肪族侧链,XI和NI煤表面结构中氧的赋存形态以“C—O”为主,“C═O”和“COO—”明显高于富镜煤。XV和XI煤的芳碳率分别为57.91%和66.02%,脂甲基碳分别为10.02%和7.84%,质子化芳碳为非质子化芳碳的两倍,XV煤的羰基和羧基碳相对含量较高,两者桥碳和周碳之比分别为0.25和0.40,芳香核结构平均缩合环数分别为2.68和3.03,平均尺寸分别为0.448和0.676 nm,XI煤结构中芳香核以萘和蒽为主,支链化度Lγ分别为0.22和0.19,表明XV比XI存在较多脂肪侧链、饱和环结构,生烃(油)潜力大。  相似文献   

4.
Mechanism and properties of thermally biological effect of Micro waves   总被引:9,自引:0,他引:9  
水在生命体中是大量存在的,它是维持生命的必要物质.它能促进细胞的繁殖和血液的循环,促进和参与生物化学反应,为生物大分子的功能发挥提供适当条件.由于它是具有一定偶极矩的微观小分子,其转动频率是处在微波范围内,所以我们判定生物体中的液态水能吸收一定频率和强度的微波,并可以将所吸收的微波能量转化为水分子无规运动的热能,使水温升高.我们的实验结果应证了这个机制,从而可导致血液循环,细胞繁殖和一些生化反应的加快和增强DNA,蛋白质和酶的生物活性等生物功能.这就是毫米波的生物热效应的机理和特性.  相似文献   

5.
以地黄饮中两味君药山茱萸肉及肉苁蓉的主要成分马钱苷、松果菊苷的提出量及出膏率为指标,对湿法粉碎提取法与煎煮法的提取效率进行了比较研究。结果显示,湿法粉碎提取法所得马钱苷、松果菊苷的量、出膏量较煎煮明显提高。湿法粉碎提取法提取效率高,方法简便,时间短,可用于地黄饮提取。  相似文献   

6.
Soil has its origin in physical processes of comminution and abrasion of rock masses and in chemical processes of solution and recrystallization of rock minerals. After formation it is transported and distributed by a variety of agencies before subaerial or subaqueous deposition. Generally, soils experience a number of cycles of sedimentation, uplift, erosion and redeposition. Their mechanical behaviour under the stresses imposed by engineering structures varies with the type of soil. Both the deformation and failure of soils are of interest in the design of structures and these properties must be studied by special laboratory tests. The solution of a soil engineering problem therefore involves a field investigation and sampling programme to define the boundaries of the soil involved, laboratory testing of the soil, and analytical or computer calculations to determine the displacements and stresses which will occur in the soil and structure. Problems of particular interest include slope failures, the design of earth dams, retaining walls and piled structures, the displacement and failure of soil under buildings and the determination of soil properties on the surface of the moon and other planets.  相似文献   

7.
Menopausal hot flashes are episodes of flushing, increased heart rate, skin blood flow and skin temperature, and a sensation of heat. The thermoregulatory and cardiovascular concomitants of hot flashes are associated with peaks in the levels of various hormones and neurotransmitters in the peripheral circulation. Although hot flashes affect about 75% of women, and are the primary reason that women at menopause seek medical attention, the mechanism of hot flashes is still not understood. Hot flashes vary in frequency and intensity both within and between individuals, and have been thought of as occurring randomly. Yet, some women report that their hot flashes are worse at a particular time of day or year. Initial examination of subjects' recordings of their hot flashes showed diurnal patterns of hot flash occurrence. There also seems to be a diurnal rhythm of hot flash intensity. Continuous physiological monitoring of hot flashes is facilitating the analysis of these patterns, which is revealing circadian and ultradian periodicities. The occurrence of hot flashes can be modulated by external and internal factors, including ambient temperature and fever. Rhythms of thermoregulatory and endocrine functions also may influence hot flash patterns. Examination of the interrelationships between the various systems of the body involved in hot flashes, and a multidisciplinary approach to the analysis of hot flash patterns, will aid our understanding of this complex phenomenon.  相似文献   

8.
研究了用碳粉和二氧化钛作缓冲剂同时测定乳浊料中的锆和铪的发射光谱法,选择钛作内标线,不需分离、不需化学处理,直接压样于杯形的石墨电极中,具有简便、快速、准确的特点。对测定条件、干扰因素进行了研究,从而建立测定锆和铪的新方法。锆和铪的分析线分别为327.3和286.6 nm,内标线选择为钛的308.8 nm线,锆和铪的线性范围分别为0~0.50%和0~0.25%。锆和铪的检测限分别为0.001%和0.010%,其回收率为96.67%~105.0%,当n=9时,锆的RSD为3.61%;铪的RSD为4.82%;用于样品的测定取得了满意的结果。  相似文献   

9.
Characteristic features of photochemical hole-burning (PHB) in the impurity spectra of low-temperature solids and PHB applications in molecular spectroscopy are considered. The evolution of a no-phonon hole and a phonon sidehole in excitation and fluorescence spectra is analysed on the basis of model calculations. Some more complex models for PHB are considered, which take into account reverse reactions, the optical thickness of the sample, the inhomogeneous dispersion of both homogeneous linewidths and transition energies of the photoproduct and quasi-static impurity-impurity interactions. The effects of PHB on fluorescence line narrowing are discussed. By PHB homogeneous linewidths of purely electronic and vibronic no-phonon lines in the spectra of some porphine and phthalocyanine derivatives in various matrices are measured and their temperature dependence is studied. The latter is found to be essentially different in polycrystalline and glassy matrices. Line-broadening mechanisms are discussed. By PHB the existence of an inhomogeneous distribution of vibrational frequencies in molecular impurities is established. The applications of PHB in the studies of photochemical reactions in solid solutions of phthalocyanine derivatives and tetracene are regarded and the mechanisms of these reactions are discussed. The results obtained by PHB for chlorophyll and its derivatives are presented.  相似文献   

10.
Surface chemistry of nanodiamonds   总被引:2,自引:0,他引:2  
The experimental data available in the literature and the results obtained by the author in research into the structure of nanodiamonds and the physicochemical and chemical properties of their surface are generalized. An account is given of the problems concerning the chemical state and modification of the nanodiamond surface in gaseous and liquid media and the infiuence of modification on the sorption and catalytic properties of nanodiamonds, their compactibility, and sintering. The similarity and difference in the behavior of nanodiamonds and diamond macrocrystals in oxidation processes are discussed. The activation energies of oxidation of nanodiamonds by different reagents are determined in the absence and presence of catalysts.  相似文献   

11.
不同比例有机无机肥配施土壤腐殖质组分的光谱学特征   总被引:3,自引:0,他引:3  
以16年长期定位试验为基础,探讨不同比例有机无机肥配施对土壤腐殖质特征的影响。通过分离纯化腐殖质中的胡敏酸(HA)和富里酸(FA)组分,并利用元素分析、红外光谱和核磁共振研究分析了F1(70%化肥+30%有机肥)、F2(50%有机肥+50%化肥)和F3(100%有机肥)三种施肥方式下的HA和FA含量及结构变化。结果表明,F3对于提升HA和FA含量的效果优于F1和F2处理,说明有机肥的施用量越高,土壤腐殖质组分的含量就越高。元素分析表明,不同配比的有机无机肥对HA和FA各元素含量及原子比影响不同。F2和F3都提高了HA的缩合度,降低了氧化度和极性,其中F3的效果更加明显;有机肥的施用还能促进HA中含氮化合物的形成,并且在F2中的效果最好;有机肥的施用同样提高了FA的缩合度而降低了氧化度和极性并促进了含氮化合物的形成,尤其在F2处理中尤为明显。腐殖质红外光谱分析表明,与F1相比,F2和F3提高了HA中脂肪族化合物、碳水化合物物质的含量,FA的羧基基团、脂肪基团含量也增加,且在F3处理中表现最为显著;F2处理则降低了HA中脂肪烃物质的含量,FA中的碳水化合物则达到最高。13C核磁共振波谱分析显示,在三种处理中,有机肥的施用提高了HA和FA的脂化度而降低其芳化度,其中F2处理中HA官能团变化更加显著,FA在F3处理中则变化更加明显。综上所述,有机肥显著提高了土壤腐殖质组分含量,并且提高了HA和FA的脂化度降低其芳化度,但是不同用量有机肥下HA和FA的形成机制不同。  相似文献   

12.
Elastic models of vocal fold tissues   总被引:4,自引:0,他引:4  
Elastic properties of canine vocal fold tissue (muscle and mucosa) were obtained through a series of experiments conducted in vitro and were modeled mathematically. The elastic properties play a significant role in quantitative analysis of vocal fold vibrations and theory of pitch control. Samples of vocalis muscle and mucosa were dissected and prepared from dog larynges a few minutes premortem and kept in a Krebs solution at a temperature of 37 +/- 1 degrees C and a pH of 7.4 +/- 0.05. Samples of muscle tissue and mucosa were stretched and released in a slow, sinusoidal fashion. Force and displacement of the samples were measured with a dual-servo system (ergometer). After digitization, stress-strain data for samples of muscle tissue and cover tissue were averaged. The stress-strain data were then fitted numerically by polynomial and exponential models.  相似文献   

13.
激光外差光谱技术是近年迅速发展的一种高光谱分辨率遥感探测技术,其装置具有体积小、光谱分辨率高等特点,适用于大气温室气体浓度的探测。各种观测实验已证明其是一种切实、有效的探测手段,在地球大气探测领域具有很大的应用前景和潜力。在现有激光外差光谱仪器的基础之上,提出了一种新型的仪器结构。采用光纤光开关对直射的太阳光进行调制与分束,实现利用单个光纤光开关进行两个波段激光外差信号的同时探测。为全光纤激光外差光谱仪的下一步系统集成和多波段激光外差光谱仪的构建提供了新方法。从激光外差探测的原理出发,分析了激光外差光谱探测技术的优势和关键参数,并结合自行研制的高精度太阳跟踪仪,搭建了一套近红外双通道全光纤式激光外差辐射计的原理样机。详细地阐述了激光外差辐射计原理样机中各功能模块的作用和参数,着重描述了光纤光开关在其中的作用原理和功能,详细地讨论了激光外差光谱仪的波长扫描模式和波长标定方法。在此基础上,讨论了激光外差辐射计的相关参数设置依据和仪器函数的测量方法,并给出了激光外差装置的仪器函数以及相应的光谱分辨率(0.004 4 cm-1)。利用搭建的激光外差光谱仪在合肥地区(31.9°N, 117.166°E)进行了实际的大气探测,同时在波段(6 056.2~6 058.1 cm-1)和(6 035.6~6 036.5 cm-1)分别获取了CH4和CO2分子的激光外差吸收信号,并对吸收信号进行了波长标定和归一化,得到了CH4分子和CO2分子的整层大气透过率谱,测量光谱信号的信噪比分别为197和209,同时也对分子吸收信号的光谱特征进行了分析。本文的测量实践表明光纤光开关可以用于激光外差光谱系统的结构优化,实现多通道多波段的激光外差光谱同时测量,拓展激光外差光谱仪在大气探测领域的应用。  相似文献   

14.
刘全喜  钟鸣 《物理学报》2010,59(12):8535-8541
建立了激光二极管阵列(LDA)端面抽运棒状激光介质的数值模型.考虑到介质与空气的对流换热和介质的热力学参数随温度的变化,根据经典热传导方程和热弹性方程,运用有限元法得出了复合棒状介质和未复合棒状介质内瞬态温度、热应力和应变的时空分布,分析了温度、热应力和应变随抽运功率、换热系数和时间的变化规律.结果表明,复合棒的最高温度、最大张应力和最大轴向应变的位置与未复合棒不同,并且数值分别为未复合棒的73%,60%和33%.由此可知,利用复合棒可极大地减小热效应的影响.理论分析结果可为LDA抽运固体激光器的结构优化设计和实验研究提供理论参考.  相似文献   

15.
胆酸与硫酸加热产生脱水反应,形成共轭双键,在紫外区产生特征吸收峰。用紫外-分光光度法测定了牛胆粉与羊胆粉中胆酸的含量。测定线性范围为0·0033~0·0167mg·mL-1(r=0·9997),加样回收率及RSD分别为98·48%,1·79%,96·46%,2·50%。5批次样品测定表明:牛胆粉中胆酸的含量在40·85%~43·03%之间,羊胆粉在30·88%~32·64%之间。牛胆粉精密度RSD为2·41%,羊胆粉精密度RSD为2·92%。稳定性试验在8h之内测定牛胆粉RSD为0·55%,羊胆粉RSD为0·59%。重复性试验牛胆粉RSD为2·11%,羊胆粉RSD为2·68%。方法简便、快速、便于推广应用,且可有效地控制牛胆粉与羊胆粉的内在质量。  相似文献   

16.
应用原子吸收光谱法测定了两份耐盐性不同的野生披碱草种质材料在不同盐浓度胁迫条件下根组织和叶组织中的大量元素(Na,K,Ca,Mg)和微量元素(Cu,Fe,Mn,Zn)含量,并对野生披碱草种质材料矿质元素吸收和积累的选择性与耐盐性的关系进行了分析,结果表明:随着盐胁迫浓度的升高,野生披碱草种质材料叶和根组织中Na含量不断增加,耐盐材料HS叶组织中的Na含量显著低于敏盐材料LS(P<0.05);而K和Ca含量呈下降的趋势,在高浓度盐胁迫下,耐盐材料HS中两种元素的含量显著高于敏盐材料LS(P<0.05);微量元素Fe和Zn在野生披碱草材料根、叶组织中的含量升高,Cu在根组织中的含量没有变化,但是在叶组织中升高,而Mn在根、叶组织中的含量都呈下降的趋势,耐盐材料HS叶组织和根组织中Zn和Fe含量低于敏盐材料LS,Mn含量显著高于敏盐材料LS(P<0.05)。  相似文献   

17.
陈杰  范大鹏 《应用光学》2017,38(3):372-380
航空重力仪是一款对地球重力进行测量的精密仪器,为了使重力仪在工作状态下隔离飞机飞行过程中的各种扰动,始终保持竖直稳定状态,设计了一款高精度航空重力仪惯性稳定平台。同时为了缩短稳定平台设计周期,并保证所设计的稳定平台系统结构方面的性能能够满足设计指标的要求,对所设计的高精度航空重力仪惯性稳定平台进行机电联合建模仿真,建立了基于Adams和Simulink的机电联合仿真模型,对机电联合仿真模型进行了时域和频域仿真分析,得到稳定平台时域与频域的基本性能指标,并把仿真结果和实际测试结果进行了对比。结果表明:在开环的条件下,时域与频域仿真结果和实际测试结果基本一致,俯仰轴幅频匹配度在83%,相频匹配度在79.2%,横滚轴幅频匹配度在92.9%,相频匹配度在86.1%,2个轴的时域匹配基本类似,验证了仿真模型的正确性和有效性。该模型可对稳定平台的伺服性能进行预测,为平台的实际测试与调试打下基础。  相似文献   

18.
THz时域光谱在蛋白质研究中的应用进展   总被引:2,自引:0,他引:2  
太赫兹时域光谱 (THz-TDS)是基于飞秒超快激光技术的远红外波段光谱测量新技术,近年来在生命科学、医学制药、安全检测等不同研究领域中的应用进展迅速。文章结合THz-TDS技术的特点及其在生物分子光谱学研究中的物理基础,介绍了近年来利用THz-TDS技术研究氨基酸、肽和蛋白质的结构、构象、动力学及无标记检测等方面取得的成果和最新进展;总结了不同实验条件下测定的不同氨基酸、同种氨基酸异构体及肽在THz波段的吸收系数和折射率,并对不同实验室测定的结果进行了比较;阐述了THz-TDS技术研究干的、含水的蛋白质粉末以及蛋白质溶液的构象及动力学;介绍了THz-TDS技术在生物素-抗生物素蛋白无标记生物传感中的应用,并初步探讨了该技术在生物分子领域应用中有待解决的问题及发展前景。  相似文献   

19.
The in-plane vibration of a complex cable-stayed bridge that consists of a simply-supported four-cable-stayed deck beam and two rigid towers is studied. The nonlinear and linear partial differential equations that govern transverse and longitudinal vibrations of the cables and transverse vibrations of segments of the deck beam, respectively, are derived, along with their boundary and matching conditions. The undamped natural frequencies and mode shapes of the linearized model of the cable-stayed bridge are determined, and orthogonality relations of the mode shapes are established. Numerical analysis of the natural frequencies and mode shapes of the cable-stayed bridge is conducted for various symmetrical and non-symmetrical bridge cases with regards to the sizes of the components of the bridge and the initial sags of the cables. The results show that there are very close natural frequencies when the bridge model is symmetrical and/or partially symmetrical, and the mode shapes tend to be more localized when the bridge model is less symmetrical. The relationships between the natural frequencies and mode shapes of the cable-stayed bridge and those of a single fixed–fixed cable and the single simply-supported deck beam are analyzed. The results, which are validated by commercial finite element software, demonstrate some complex classical resonance behavior of the cable-stayed bridge.  相似文献   

20.
A distinct knowledge of the relationship between physiochemical properties, cellular distribution and relaxation efficacy of particulate MR contrast media is needed for the development of tissue specific contrast compounds. To study these relations paramagnetic gadolinium labelled microspheres and superparamagnetic iron oxide microspheres (MSM) were injected intravenously to rats. The T1 and T2 relaxation times of the liver and spleen were recorded and the gadolinium tissue content quantified. A clear relationship between the gadolinium dose and the gadolinium concentration of the liver and spleen was observed while the T1 of the tissues remained unchanged. After injection of MSM, T2 of liver and both T1 and T2 of spleen decreased dose-dependently. The splenic relaxation efficacy of MSM was higher compared with that of liver, probably due to the morphology of the spleen allowing a scattered cellular sequestration of MSM. To mimic a uniform tissue distribution of the contrast agents, the liver and spleen samples were homogenized and a marked increase in the intrinsic relaxation efficacy of both the paramagnetic and superparamagnetic microspheres was observed.  相似文献   

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