共查询到20条相似文献,搜索用时 125 毫秒
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抑制共晶产生对低温保存非常重要。本文利用差示扫描量热法研究了加低温保护剂(DMSO、乙二醇、 1,2丙二醇、甘油和1,3丁二醇)的NaCl水溶液的共晶行为。得到以5%、10%、15%NaCl水溶液为母液的五种保护剂溶液热流曲线图。研究发现,溶液共晶是过冷、随机过程。低温保护剂有抑制NaCl水溶液共晶的作用。低温保护剂浓度越高, 共晶焓越小,对共晶的抑制作用越大。不同种类保护剂的抑制共晶的能力从强到弱依次是甘油、乙二醇、 DMSO、 1,2 丙二醇和1,3丁二醇。升温过程中,溶液发生共晶反玻璃化现象和玻璃化现象。 相似文献
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为进一步完善动脉低温保存过程中为解决低温断裂问题而建立的冻结过程的热应力分析物理模型,本文研究家兔主动脉血管从室温到-80℃温度范围内,杨氏模量随温度的变化情况和加抗冻剂CPA的影响。研究发现兔丰动脉低温冻结状态的杨氏模量随温度的降低而增大;加CPA对兔丰动脉血管冻结状态下的杨氏模量有影响,相同温度情况下加CPA试样的杨氏模量比不加CPA试样的要低。 相似文献
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应用原位X射线衍射法对盐湖卤水体系的两个子体系--NaCl-H2O和NaCl-KCl-H2O溶液在低温条件下进行扫描,获得了实验条件下体系的衍射图谱,得到了溶液低温相变过程的信息。图谱解析结果表明:含NaCl 26.25%的溶液在-20~-25℃范围内析出了冰、NaCl、低水合氯化钠和二水氯化钠,含NaCl 25.70%的溶液没有发生相变;对于NaCl-KCl-H2O体系,含NaCl 20.03%和KCl 10.19%的溶液在0~-25 ℃范围内析出了氯化钾和氯化钠,含NaCl 22.40%和KCl 7.28%的溶液在-10~-25 ℃范围内只有氯化钾析出,含NaCl 21.90%和KCl 6.46%的溶液没有发生相变。实验结果显示:这两个水盐体系低温相变过程析出盐的种类与相图结果有差异,原因在于两者的状态不同;体系中二水氯化钠的析出需要经过氯化钠与水的化合过程,该过程是分步进行的;实验体系在低温条件下发生相变受结晶因素控制,温度只是其中一个因素,体系相变发生与否是结晶因素综合影响的结果。 相似文献
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A. Rueda 《Foundations of Physics》1974,4(2):215-226
The local aspect of the thermalization of thermal radiation due to the interaction of thermal radiation with matter is explored. It is shown that for absorption and emission interactions some well-known phenomenological statements of irreversible thermophysics are indeed relevant. For scattering interactions the entirely different picture that emerges is also briefly discussed. The local analysis is based on the concepts of temperature and entropy of nonequilibrium thermal radiation fields, as originally introduced by Planck, and shows that these concepts are susceptible of a very natural thermodynamic interpretation. 相似文献
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从正则系综的基本公式出发,绕开对位形积分的具体计算,结合热力学能态方程,求出了e-1<压缩因子Z0, p0)附近压力与温度的一般解析式,并与实验值进行了对照。应用本文导出的公式在工程热物理方面可减少实验测试的次数,在石化工业中可用来计算环境温度的变化对高压储气罐内压力的影响。 相似文献
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Chakraborty S 《Physical review letters》2007,99(9):094504
A novel phase-field approach is developed for quantitative modeling of the complex thermophysics over reduced length scales in narrow fluidic confinements, as induced by the surface roughness-hydrophobicity coupling and the consequent hydrodynamic interactions. The method is tested for flows on micro- and nano- corrugated surfaces in narrow confinements, and the agreement with molecular dynamics and lattice Boltzmann simulations is found to be quantitative. 相似文献
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Intensification of aeration and mass transfer in wastewater treatment by discrete-pulse energy input
The article focuses on the application of thermophysics in environmental protection, namely the wastewater treatment due to mass transfer enhancement and acceleration of the reaction of biological oxidation. Intensification results from the effect of the discrete-pulse energy input (DPEI) method on the treated medium (wastewater). The method is implemented by means of a new heat-and-mass equipment, namely, an aerator-oxidizer of rotor type. 相似文献
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Some engineering approaches to the problems of optics and thermophysics of biological tissues have been developed. The light
fields both within and beyond biological medium have been studied. The role of the epidermis in the formation of these fields
is revealed. It is shown that in the general case epidermis cannot be considered as a spectral filter that only absorbs and
does not scatter light. A convenient approximation of the fluence rate in a two-layer (epidermis and dermis) tissue is proposed,
which is the sum of two exponential functions of depth in the epidermis. This approximation made it possible to obtain an
analytical solution to the problem of heating biological tissues by an external narrow light beam. It is found that epidermis
only slightly affects the temperature fields under blue light irradiation. However, when an external source of red light is
used, the epidermis works as a heater and can increase several times the dermis temperature in comparison with a single-layer
tissue. The reasons for these heating features are discussed. Examples of corresponding calculations are given. 相似文献