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1.
We think that the thermally biological effects of millimeter waves are caused by the thermal motions of water molecules in the living systems, according to experimental fact that the millimeter waves can heat water, and the skin effect on the surface of the biological tissues arising from the millimeter waves. For clarifying this idea we studied the states and features of the liquid water and calculated the rotational energy-spectra of water molecules in the living systems by quantum mechanics. In fact, there is a large number of water which are polarized and have certain dipole moments in the living systems. This shows that the millimeter waves can interact with the water molecules. Through calculation of quantum rotational energy-spectra of the water molecules, we can confirm that the water molecules can absorb the millimeter waves with certain wavelength to generate the rotations of water molecules according to the principle of resonant absorption. One mechanism of the thermally biological effect of the millimeter waves is just a result produced by disorderly thermal-motions of the water molecules which are transformed from their rotation energy caused by the millimeter waves. Owing to the fact that water has a lot of biological functions and plays an important role in the living activity. Thus the heating waters by the millimeter waves can cause a lot of biological effects and phenomena in the living systems. Another mechanism of the thermally biological effect of the millimeter waves is caused by the Joule-Lenz heat arising from the skin effect of the millimeter waves in the skin layers of human beings and animals and membranes of cells which can facilitate the blood circulation in them. We finally study this effect.PACSnumbers: 87.50.Hj; 05.70.Ce; 87.15.He; 65.50.tm.  相似文献   

2.
thermally biological effects of infrared lights absorbed have been studied by nonlinear quantum theory and molecular biological theory on the basis of structures of cell and water molecules. There is a large number of water in the living systems, it play an important role in living activity, and has a lot of biological functions. There would be no life without water. We can confirm that the thermally biological effect is a result produced by disorder motions of bio-water-molecules according to the essence of heat, feature of molecular structure of water, theory of molecular physics, principle of resonante absorption and experimental fact that infrared light can heat liquid water. Therefore, mechanism of this effect is that the infrared light absorbed results in the quantum vibrations of water molecules with hydrogen bonds, the vibrational energy again transformes as thermal energy of disorder motions of a great number of water molecules in the living systems. The heating waters can cause a lot of biological effects and phenomena to occur in the living systems. Therefore, the infrared lights absorbed by the living systems have some medical functions.  相似文献   

3.
ASTATISTICALTHEORYFORTHEBIO-PHOTONEMISSIONOFTHELIVINGSYSTEMSPangXiaofengInternationalCentreforMaterialPhysics,AcademiaSinicaD...  相似文献   

4.
This paper discusses the Nonequilibrium Zeldovich-von Neumann-Doring (NEZND) theory of self-sustaining detonation waves and the Ignition and Growth reactive flow model of shock initiation and detonation wave propagation in solid explosives. The NEZND theory identified the nonequilibrium excitation processes that precede and follow the exothermic decomposition of a large high explosive molecule into several small reaction product molecules. The thermal energy deposited by the leading shock wave must be distributed to the vibrational modes of the explosive molecule before chemical reactions can occur. The induction time for the onset of the initial endothermic reactions can be calculated using high pressure-high temperature transition state theory. Since the chemical energy is released well behind the leading shock front of a detonation wave, a physical mechanism is required for this chemical energy to reinforce the leading shock front and maintain its overall constant velocity. This mechanism is the amplification of pressure wavelets in the reaction zone by the process of de-excitation of the initially highly vibrationally excited reaction product molecules. This process leads to the development of the three-dimensional structure of detonation waves observed for all explosives. For practical predictions of shock initiation and detonation in hydrodynamic codes, phenomenological reactive flow models have been developed. The Ignition and Growth reactive flow model of shock initiation and detonation in solid explosives has been very successful in describing the overall flow measured by embedded gauges and laser interferometry. This reactive flow model uses pressure and compression dependent reaction rates, because time-resolved experimental temperature data is not yet available. Since all chemical reaction rates are ultimately controlled by temperature, the next generation of reactive flow models will use temperature dependent reaction rates. Progress on a statistical hot spot ignition and growth reactive flow model with multistep Arrhenius chemical reaction pathways is discussed. The text was submitted by the authors in English.  相似文献   

5.
张锡奇  闻利平  江雷 《物理学报》2019,68(1):18801-018801
低维限域结构中水与物质的输运研究,对于解决界面化学和流体力学中的遗留问题十分关键.近年来,研究人员采用分子动力学模拟和实验手段研究低维限域结构中水与物质的输运,并将其应用于物质输运、纳米限域化学反应、纳米材料制备等领域.本文从理论和实验的角度总结一维和二维纳米通道的水与物质输运,介绍了本研究组提出的"量子限域超流体"概念,并用于解释纳米通道中超快物质的输运现象;在此基础上概述了一维纳米通道中的分子动力学模拟和水浸润性,以及外部环境(如温度和电压)对限域结构中水浸润性的调控,同时阐述了低维限域结构中的液体输运;对二维纳米通道中的分子动力学模拟、液体浸润性以及液体输运进行了综述;讨论了纳米通道限域结构在物质输运、纳米限域化学反应和纳米材料制备等领域的应用;对低维限域结构中水与物质输运面临的挑战和前景进行了展望.  相似文献   

6.
We review a theory for coupled many-nonlinear oscillator systems that describes quantum ergodicity and energy flow in molecules. The theory exploits the isomorphism between quantum energy flow in Fock space, that is, vibrational state space, and single-particle quantum transport in disordered solid-state systems. The quantum ergodicity transition in molecules is thereby analogous to the Anderson transition in disordered solids. The theory reviewed here, local random matrix theory (LRMT), describes the nature of the quantum ergodicity transition, statistical properties of vibrational eigenstates, and quantum energy flow through the vibrational states of molecules. Predictions of LRMT have been observed in computational studies of coupled nonlinear oscillator systems, which are summarized here. We also review applications of LRMT to molecular spectroscopy and chemical reaction rate theory, including adoption of LRMT in theories that predict rates of conformational change of molecules taking place at energies corresponding to those below and above the quantum ergodicity transition. A number of specific examples are reviewed, including the application of LRMT to predict (1) dilution factors of IR spectra of organic molecules, (2) rates of conformational change in chemical and photochemical reactions, (3) conformational dynamics of biological molecules in molecular beams, (4) rates of hydrogen bond breaking and rearrangement in clusters of biological molecules and water, and (5) excited state proton transfer reactions in proteins.  相似文献   

7.
马丙现  贾瑜  姚宁  杨仕娥  张兵临 《物理学报》2005,54(9):4300-4308
阐述了模板的动力学控制作用对大尺度有序结构特别是亚稳相的生长,对自由能相差很小的异构体的选择生长所具有的重要作用.汲取现有金刚石生长理论的合理思想,以模板概念为基础给出了对化学气相沉积(CVD)过程的动力学热力学综合描述:1)碳原子在碳氢化合物中的化学势高于固相碳,气相碳氢化合物的碳原子有可能落到化学势较低的固态碳的各种异构体.2)气相碳通过表面反应实现向固相碳的转化.3)表面的模板作用是控制气相碳原子转换方式的主要动力学因素,不同的表面(石墨各种取向的表面及金刚石不同取向的表面)选择了落入其上的碳原子的结构方式及能量状态.4)因此,衬底的不同区域可发生几种不同的独立的表面反应过程,这些反应对应于不同表面的生长.5)而这些表面反应的方向性及速度受表面临域热力学因素的影响,反应的方向性决定了某种晶面是生长或刻蚀,在特定的温度、压强及各种气体分压下可以实现金刚石的生长和石墨的刻蚀.6)衬底局域晶格结构及键价结构和衬底表面气相的温度、压强及各种气体分压等热力学条件共同决定了成核的临界条件.7)与外界有能量和物质交换的等离子体系统,以及气相中发生的一系列化学反应,仅起到了维持某种固相表面生长所需要的非平衡热力学条件和化学条件的作用.金刚石和石墨表面具有的模板动力学控制作用,在特定热力学条件下主导自身外延层的生长方式;异质衬底的某些局域微观结构可以作为新相生长成核的局域模板;不同材料、不同的处理方法、及不同的化学环境下的衬底具有不同的局域微观结构,从而决定了多晶薄膜的取向优势. 关键词: 模板 异构体 选择性生长 金刚石薄膜  相似文献   

8.
Abstract

The study is focused on the dolomite-limestone drinking water aquifers in the Bo? massif, as well as on the andesite-aquifer containing mineral water in the vicinity of Roga?ka Slatina. The catchment area is limited and both drinking and mineral waters are discharged from the same source. The increasing use of deeper aquifers means that natural springs and shallow wells have become sporadic. Consequently new techniques of investigating recharge and aquifer capacity are required which can augment classical hydrogeological methods.

Current research into the mineral and drinking water aquifers in the area of Roga?ka Slatina is based on measuring the isotopic composition of light elements, (H, C and O) as natural tracers. It can be concluded that all the groundwaters investigated are typically infiltrated meteoric water. The drinking waters are generally young and were infiltrated up to about ten years ago. The isotopic composition of oxygen is similar to recent precipitation (δ18O = -9.3 ± 1‰) and the drinking waters contain tritium. It was found that exploited mineral waters recharged aquifers during colder periods; they are only partly mixed with younger water as can be seen from the isotopic composition of oxygen and corrected 14C dating, which puts the mean ages at between around 100 and 8,000 years. With regard to the “nuclear period” (1960-64) with abnormally high tritium activities of precipitation, all the waters examined can be divided into at least three main infiltration groups depending on their measured tritium content: around 35 years old (> 80 T.U.), older (> 10 T.U.) and younger (10 to 60 T.U.). Detailed dating is possible following the above classification. Isotope exchange between rocks and water is negligible and therefore very deep circulation at the temperature conditions above 80°C does not occur. Dissolved inorganic carbon (DIC) in the drinking waters is the result of equilibrium reactions between carbonates and organically produced CO213C = - 14.5 ± ‰), while the high concentrations of DIC (δ13C = + 3 ±‰) and CO2 observed in the mineral waters are generated by low-temperature decarbonatization processes and indicate the deep origin of CO2, from where gas migrates into mineral water aquifers.

Correlation analyses between the parameters studied are performed. Useful conclusions concerning water circulation and the capacities of aquifer reservoirs are described which support the future optimal pumping of mineral and drinking water at the limited catchment area of Roga?ka Slatina and Bo?.  相似文献   

9.
Biological surface science   总被引:15,自引:0,他引:15  
Bengt Kasemo   《Surface science》2002,500(1-3):656-677
Biological surface science (BioSS), as defined here is the broad interdisciplinary area where properties and processes at interfaces between synthetic materials and biological environments are investigated and biofunctional surfaces are fabricated. Six examples are used to introduce and discuss the subject: Medical implants in the human body, biosensors and biochips for diagnostics, tissue engineering, bioelectronics, artificial photosynthesis, and biomimetic materials. They are areas of varying maturity, together constituting a strong driving force for the current rapid development of BioSS. The second driving force is the purely scientific challenges and opportunities to explore the mutual interaction between biological components and surfaces.

Model systems range from the unique water structures at solid surfaces and water shells around proteins and biomembranes, via amino and nucleic acids, proteins, DNA, phospholipid membranes, to cells and living tissue at surfaces. At one end of the spectrum the scientific challenge is to map out the structures, bonding, dynamics and kinetics of biomolecules at surfaces in a similar way as has been done for simple molecules during the past three decades in surface science. At the other end of the complexity spectrum one addresses how biofunctional surfaces participate in and can be designed to constructively participate in the total communication system of cells and tissue.

Biofunctional surfaces call for advanced design and preparation in order to match the sophisticated (bio) recognition ability of biological systems. Specifically this requires combined topographic, chemical and visco-elastic patterns on surfaces to match proteins at the nm scale and cells at the micrometer scale. Essentially all methods of surface science are useful. High-resolution (e.g. scanning probe) microscopies, spatially resolved and high sensitivity, non-invasive optical spectroscopies, self-organizing monolayers, and nano- and microfabrication are important for BioSS. However, there is also a need to adopt or develop new methods for studies of biointerfaces in the native, liquid state.

For the future it is likely that BioSS will have an even broader definition than above and include native interfaces, and that combinations of molecular (cell) biology and BioSS will contribute to the understanding of the “living state”.  相似文献   


10.
 将速率方程(RE)模型与化学动力学模型相结合,讨论了增益饱和模型与化学反应系统对COIL性能的影响。流动为预混的一维模型,考虑了10种成分和21个化学反应,分析计算了未分解碘分子,激发态氧产率,水含量以及温度等因素对COIL性能的影响。计算结果表明,碘流量过多,混合和反应过程中消耗大量能量;碘流量过低,导致粒子数反转和增益过低,对于能量的提取不利。  相似文献   

11.
The inside of the cell is a complex environment that is difficult to simulate when studying proteins and other molecules in vitro. We have developed a device and system that provides a controlled environment for nuclear magnetic resonance (NMR) experiments involving living cells. Our device comprises two main parts, an NMR detection region and a circulation system. The flow of medium from the bottom of the device pushes alginate encapsulated cells into the circulation chamber. In the chamber, the exchange of oxygen and nutrients occurs between the media and the encapsulated cells. When the media flow is stopped, the encapsulated cells fall back into the NMR detection region, and spectra can be acquired. We have utilized the bioreactor to study the expression of the natively disordered protein α-synuclein, inside Escherichia coli cells.  相似文献   

12.
本文探讨了循环水流量﹑热水温度及环境温度等参数对小型复叠式空气源热泵采暖系统性能的影响。实验结果表明:在一定温度范围内,随着制取热水温度的升高,热泵的制热量逐渐降低,热泵的输入功率逐渐增大,系统COP呈下降趋势;当制取的热水温度相同、环境温度较高时,热泵的制热量、热泵平均COP值较高;在一定流量范围内,循环流量越大,热泵的制热能力越高,当制取热水的温度相同时,大循环流量下高温环路的压缩机排气温度越低,运行越稳定。  相似文献   

13.
In this paper, the electron transfer reactions in the microwave field are studied. A classical theory is developed for a mix of reagents and polar frequency-dispersive and lossy solvent filling vessels excited by microwaves. These reactors are described by a system of non-linear partial self-consistent differential equations for non-stationary microwave field, heat and liquid dynamics, and chemical molecular kinetics. A particular solution of this system is considered for the isothermic electron-transfer reactions in the microwave field varying its frequency with the calculation of the normalised Marcus rate coefficient. It is found that for the small normalised reaction free energy, the chemical reactions are supported by microwaves in a wide frequency band with an increased value of the exponent in the Marcus rate coefficient. At higher values of this energy, these reactions are driven only by conventional microwave heating. The restrictions for the given theory are reviewed, and further experimental and semi-classical and quantum-mechanical studies are found essential for practical applications of these findings.  相似文献   

14.
As the mechanisms of carbon nanotube (CNT) growth becomes known, it becomes important to understand how to implement this knowledge into reactor scale models to optimize CNT growth. In past work, we have reported fundamental mechanisms and competing deposition regimes that dictate single wall carbon nanotube growth. In this study, we will further explore the growth of carbon nanotubes with multiple walls. A tube flow chemical vapor deposition reactor is simulated using the commercial software package COMSOL, and considered the growth of single- and multi-walled carbon nanotubes. It was found that the limiting reaction processes for multi-walled carbon nanotubes change at different temperatures than the single walled carbon nanotubes and it was shown that the reactions directly governing CNT growth are a limiting process over certain parameters. This work shows that the optimum conditions for CNT growth are dependent on temperature, chemical concentration, and the number of nanotube walls. Optimal reactor conditions have been identified as defined by (1) a critical inlet methane concentration that results in hydrogen abstraction limited versus hydrocarbon adsorption limited reaction kinetic regime, and (2) activation energy of reaction for a given reactor temperature and inlet methane concentration. Successful optimization of a CNT growth processes requires taking all of those variables into account.  相似文献   

15.
A high resolution ultraviolet photoelectron spectrometer specifically designed to study transient and unstable species is described. Its capabilities are enhanced by the novel pumping system for the analyzer, thus removing the necessity of a large vacuum chamber, and giving close access to the ionization chamber. Additional fast pumping for the ionization chamber and versatile sampling systems are also incorporated. Spectra are presented to show the general performance and the potential of the spectrometer for studying unusual chemical systems. In particular, the design features permit studies of discharge reactions, pyrolyses, atom-molecule reactions, highly reactive molecules and variable temperature work.  相似文献   

16.
The thermal treatment by millimeter waves for the soil disinfection can be one possible alternative to chemical treatments. This physical method is based on incrementing the soil temperature and its pathogens irradiating with high frequency electromagnetic waves. So the previous knowledge of the temperature distribution in the irradiated soil is essential for achieving an effective bad microorganism and weed seeds elimination. This report analyse the heating kinetic and spatial distribution of the maximum temperatures reached by the soil. It is presented a mathematic model about how are distributed the reached temperatures in the depth of the irradiated soil. This model concludes that when an orchard soil is irradiated superficially by microwaves, the microwaves have a big attenuation due to the soil dielectric properties and the water located in the pores of the most superficial layer. This fact causes a shield effect blocking the waves penetration in few centimetres. The heating by radiation is reduced to the superficial layer. The heating propagation in the depth is occurred by conduction following the Fourier equations.  相似文献   

17.
The properties of proton transfer along hydrogen-bonded molecular systems are studied at finite temperature. The dynamic equations of the proton transport along the systems are obtained by using a completely quantummechanics method. From the dynamic equations and its soliton solutions we find out specific heat arising from the motionof solitons in the systems with finite temperature and the critical temperature of the soliton in the protein molecules,which is about 318 K. This shows that we can continuously study some biological phenomena in the living systems bythis model.  相似文献   

18.
The reactions of isolated, neutral transition metal clusters with small molecules are used to probe cluster structure and to identify changes in structure with cluster size. Examples are presented of reactivity, adsorbate uptake, and product composition studies. The general conclusion is that transition metal clusters seem to have structure (are “solid”) under typical experimental conditions, and that their structure, i.e., the way the atoms pack, can change many times in the growth sequence from small clusters to bulk metal. These phase changes are often accompanied by dramatic changes in both chemical and physical properties. Evidence is presented for the existence of isomers of certain cluster sizes for some metals. In a few cases, the chemical evidence can be used to propose possible cluster structure; this is illustrated for iron and nickel clusters.  相似文献   

19.
The properties of proton transfer along hydrogen-bonded molecular systems are studied at finite temperature. The dynamic equations of the proton transport along the systems are obtained by using a completely quantum mechanics method. From the dynamic equations and its soliton solutions we find out specific heat arising from the motion of solitons in the systems with finite temperature and the critical temperature of the soliton in the protein molecules, which is about 318 K. This shows that we can continuously study some biological phenomena in the living systems by this model.  相似文献   

20.
Reaction networks in thermodynamic equilibrium under isothermal and isobaric conditions minimize the Gibbs free energy, but chemical reactions in living organisms operate typically far from equilibrium. Currently, there is no general optimization principle for nonequilibrium systems which can be used in the analysis of biochemical networks. Motivated by the avalailabity of whole genome reconstructions of metabolic reactions, the thermodynamics of biochemical stoichiometric networks has made significant progress in the last decade. These include the consistent formulation of conservation conditions resembling Kirchhoff’s law for electrical networks. In addition, Beard and Qian suggested that the flow force relationship Δμ = RT log(J+/J) between the forward and backward fluxes J+ and J and the chemical potential difference of a chemical reaction can be extended from mass action kinetics to more general reactions schemes. In this tutorial review we summarize the recent literature on reaction network thermodynamics and discuss its implications to the analysis of large biochemical systems. In addition, we discuss some recent work on flow-force relationships and global variational principles characterizing nonequilibrium steady states of reaction networks.  相似文献   

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