Effective first law of thermodynamics of black holes with two horizons

For a black hole with two horizons, the effective entropy is assumed to be a linear combination of the two entropies of the outer and inner horizons. In terms of the effective thermodynamic quantities the effective Bekenstein-Smarr formula and the effective first law of thermodynamics are derived.

Pressure Effects on Thermodynamics of Phase Behavior in Polystyrene/Methylcyclohexane Solutions

The calculations presented in this paper are based on the Sanchez-Lacombe（SL）lattice fluid theory.The interaction energy parameter,g12/k,required in this approach was obtained by fitting the cloud points of polystyrene（PS）/methylcyclohexane（MCH）polymer solutions under pressure.The SL lattice fluid theory was used to calculate the spinodals,the binodals,and the Flory-Huggins（FH）interaction parameter of the solutions.The calculated results show that the SL lattice fluid theory can describe the dependences of thermodynamics of PS/MCH solutions on temperature and pressure very well.However,the calculated enthalpy and the excess volume changes indicate that the Clausius-Clapeyron equation cannot be suitable to describe pressure effect on PS/MCH solutions.Further analysis on the thermodynamics of this system under pressure shows that the role of entropy is more important than the excess volume in the present case.

Magnetic Effects in the Thermodynamics of Information

The authors have shown that the process data can be modeled on the basis of chemical thermodynamics. The authors offer general information of the equation in the presence of a magnetic field. As a result, studies have shown that the magnetic effects strongly influence the thermodynamics of information.

Magnetic Effects in the Thermodynamics of the Process of Thinking

The authors have shown that the process of information and thinking can be modeled on the basis of chemical thermodynamics. The authors offer general equations to calculate the thinking of the work of judgment the L and of entropy solutions G in the presence of a magnetic field. As a result, studies have shown that the magnetic effects strongly influence the thermodynamics of the process of thinking.

Thermodynamic Study on Antibacterial Effect of Different Extracts from Radix Isatis

Objective： To study and analyze the antibacterial effects of different extracts from Radix Isatis. Methods： Staphylococcus aureus was used as the studied object in the experiment. Antibacterial effects of extracts from Radix Isatis were observed by thermocalrimetry on Staphylococcus aureus, together with common pharmacological experiments. Results： The total extract, ethyl acetate （EtOAc） extract, n-butylalcohol （nBuOH） extract, chloroform （CHCl3） extract and petroleum （P. E.） extract had antiviral effects to some extent while the residue after extracting had no antibacterial activity. The potency of antiviral activity among them was as follows： nBuOH extract 〉 EtOAc extract 〉 CHCl3 extract〉 total extract 〉P. E. extract. Conclusion： The antibacteriall effects of Radix Isatis were not limited to any active portion, showing that Radix Isatis exerts its antibacterial effects by cooperation of different active fractions in varied ways.

Nanofabrication of 50 nm zone plates through e-beam lithography with local proximity effect correction for x-ray imaging

High resolution Fresnel zone plates for nanoscale three-dimensional imaging of materials by both soft and hard x-rays are increasingly needed by the broad applications in nanoscience and nanotechnology.When the outmost zone-width is shrinking down to 50 nm or even below,patterning the zone plates with high aspect ratio by electron beam lithography still remains a challenge because of the proximity effect.The uneven charge distribution in the exposed resist is still frequently observed even after standard proximity effect correction(PEC),because of the large variety in the line width.This work develops a new strategy,nicknamed as local proximity effect correction(LPEC),efficiently modifying the deposited energy over the whole zone plate on the top of proximity effect correction.By this way,50 nm zone plates with the aspect ratio from 4:1 up to 15:1 and the duty cycle close to 0.5 have been fabricated.Their imaging capability in soft(1.3 keV)and hard(9 keV)x-ray,respectively,has been demonstrated in Shanghai Synchrotron Radiation Facility(SSRF)with the resolution of 50 nm.The local proximity effect correction developed in this work should also be generally significant for the generation of zone plates with high resolutions beyond 50 nm.

Unraveling Shuttle Effect and Suppression Strategy in Lithium/Sulfur Cells by In Situ/Operando X-ray Absorption Spectroscopic Characterization

The polysulfides shuttle effect represents a great challenge in achieving high capacity and long lifespan of lithium/sulfur(Li/S)cells.A comprehensive understanding of the shuttle-related sulfur speciation and diffusion process is vital for addressing this issue.Herein,we employed in situ/operando X-ray absorption spectroscopy(XAS)to trace the migration of polysulfides across the Li/S cells by precisely monitoring the sulfur chemical speciation at the cathodic electrolyte-separator and electrolyte-anode interfaces,respectively,in a real-time condition.After we adopted a shuttle-suppressing strategy by introducing an electrocatalytic layer of twinborn bismuth sulfide/bismuth oxide nanoclusters in a carbon matrix(BSOC),we found the Li/S cell showed greatly improved sulfur utilization and longer life span.The operando S Kedge XAS results revealed that the BSOC modification was bi-functional:trapping polysulfides and catalyzing conversion of sulfur species simultaneously.We elucidated that the polysulfide trapping-and-catalyzing effect of the BSOC electrocatalytic layer resulted in an effective lithium anode protection.Our results could offer potential stratagem for designing more advanced Li/S cells.

Thermodynamic Effects on Particle Movement:Wind Tunnel Simulation Results

Sand/dust storms are some of the main hazards in arid and semi-arid zones. These storms also influence global environmental changes. By field observations, empirical statistics, and numerical simulations, pioneer researchers on these natural events have concluded the existence of a positive relationship between thermodynamic effects and sand/dust storms. Thermodynamic effects induce an unsteady stratified atmosphere to influence the process of these storms. However, studies on the relationship of thermodynamic effects with particles (i.e., sand and dust) are limited. In this article, wind tunnel with heating was used to simulate the quantitative relationship between thermodynamic effects and particle movement on different surfaces. Compared with the cold state, the threshold wind velocity of particles is found to be significantly decrease under the hot state. The largest decrease percentage exceedes 9% on fine and coarse sand surfaces. The wind velocity also has a three-power function in the sand transport rate under the hot state with increased sand transport. Thermodynamic effects are stronger on loose surfaces and fine particles, but weaker on compacted surfaces and coarse particles.

Process parameters influence on zone refining and thermodynamics analysis of 1,2-diphenylethane

Effective distribution coefficients of 9 impurities in 1,2-diphenylethane have been calculated by directional crystallization under different ambient frozen temperature.The effect of varied zone size,temperature difference between the melt and ambient frozen environment,number of zone on purity of 1,2-diphenylethane have been also investigated during the process of zone refining.The results indicate that the product purity in the intermediate purified region with varied zone size is higher 0.04%–0.2%than that with constant zone size.The product purity increases with temperature difference between the melt and ambient frozen environment.The appropriate temperature difference is adopted 50°C.The product purity in the intermediate region of sample bar with 2 molten zones is higher 0.05%–0.43%than that with 1 molten zone.In addition,the change of enthalpy and entropy between impurities and 1,2-diphenylethane have been determined.

Using Quantum Statistics to Win at Thermodynamics, and Cheating in Vegas

Gambling is a useful analog to thermodynamics. When all players use the same dice, loaded or not, on the average no one wins. In thermodynamic terms, when the system is homogeneous—an assumption made by Boltzmann in his H-Theorem—entropy never decreases. To reliably win, one must cheat, for example, use a loaded dice when everyone else uses a fair dice;in thermodynamics, one must use a heterogeneous statistical strategy. This can be implemented by combining within a single system, different statistics such as Maxwell-Boltzmann’s, Fermi-Dirac’s and Bose-Einstein’s. Heterogeneous statistical systems fall outside of Boltzmann’s assumption and therefore can bypass the second law. The Maxwell-Boltzmann statistics, the equivalent of an unbiased fair dice, requires a gas column to be isothermal. The Fermi-Dirac and Bose-Einstein statistics, the equivalent of a loaded biased dice, can generate spontaneous temperature gradients when a field is present. For example, a thermoelectric junction can produce a spontaneous temperature gradient, an experimentally documented phenomenon. A magnetic field parallel to, and an electric field perpendicular to a surface produce a spontaneous current along the surface, perpendicular to both fields (Reciprocal Hall Effect). Experimental data collected by several independent researchers is cited to support the theory.

Substituent Effect on Infrared Spectra and Thermodynamic Properties of Polynitroamino Substituted Cyclopentane and Cyclohexane

Density functional theory method was employed to study the effect of the nitroamino group as a substituent in cyclopentane and cyclohexane, which usually construct polycyclic or caged nitramines. Based on the optimized molecular structures of two groups of monocyclic nitramines at the B3LYP/6-31G^＊＊ level, the infrared （IR） spectra were obtained and assigned by harmonic vibrational analysis. The calculated results agree reasonably with the available experimental data. According to the principles of statistic thermodynamics, thermodynamic properties were derived from the IR spectra, which were linearly correlated with the number of nitroamino groups as well as the temperature. The contributions of nitroamino groups to thermodynamic properties are in accord with the group additivity.

Chemical Effect Analyses of 3d Elements by Study of X-Ray Fluorescence Spectra

Spectra of KX-rays emitted from pure 3 dtransition metals and their oxide and sulfate compounds were measured using a single crystal wavelength dispersive X-ray spectroscopy(WDXRF).The measurements were performed using a ZSX-100 esequential spectrometer equipped with an RhX-ray tube operated.An accurate analytical representation of each line was obtained by a fit to a Lorentz function.The spectra were analyzed in order to examine the KX-ray peak parameters such as asymmetry index,peak energy and relative intensity ratios.The energy shifts and relative intensities weredetermined tobetter understand the chemical effect.

X-Ray Radiation Sensing Properties of ZnS Thin Film:A Study on the Effect of Annealing

Chemically synthesized ZnS thin film is found to be a good x-ray radiation sensor. We report the effect of annealing on the x-ray radiation detection sensitivity of a ZnS thin film synthesized by a chemical bath deposition technique. The chemically synthesized ZnS films are annealed at 333, 363 and 393K for 1 h. Structural analyses show that the lattice defects in the films decrease with annealing. Further, the band gap is also found to decrease from 3.38 to 3.21 eV after annealing at 393K. Current-voltage characteristics of the films are studied under dark and x-ray irradiation conditions. Due to the decrease of lattice defects and band gap, the conductivity under dark conditions is found to increase from 2.06 × 10^-6 to 1.69 × 10^-5 S/em, while that under x-ray irradiation increases from 4.13 × 10^-5 to 5.28 ×10^-5 S/cm. On the other hand, the x-ray radiation detection sensitivity of the films is found to decrease with annealing. This decrease of detection sensitivity is attributed to the decrease of the band gap as well as some structural and surface morphological changes occurring after annealing.

纳米材料杨氏模量的尺度依赖性

【目的】纳米材料杨氏模量与其对应的大块材料的杨氏模量完全不同,并且具有明显的尺度依赖性,然而纳米材料杨氏模量随尺度的变化却是多样且复杂的。一些金属纳米材料杨氏模量随着尺度减小而增大,并高于块体杨氏模量值;而一些半导体纳米材料的杨氏模量却随尺度的减小而降低,且低于块体杨氏模量值。这种相反的变化趋势的原因却并不清楚。【方法】基于纳米热力学理论,以纳米材料结合能为基础,从原子势函数与材料杨氏模量的内在关系出发,引入反映材料原子键本质的参数,详细推导了纳米材料杨氏模量定量解析过程,阐述了金属、非金属等纳米材料杨氏模量值和其随尺度的变化规律;揭示了纳米材料表面模量、内部模量对体系杨氏模量的贡献,并利用材料参数阐明纳米材料杨氏模量与尺度、原子键的物理关系。【结果】所构建的理论解析模型对零维纳米颗粒、一维纳米线和二维纳米薄膜的杨氏模量都进行了成功的预测。

晃动条件下大型液氢舱罐的动力学及热力学特性

大型液氢舱罐在不同海况下会呈现出复杂的动力学响应及热力学响应,并在很大程度上影响舱罐的安全,因此,建立一个数值模型来研究晃动条件下船用大型低温舱罐中液氢的动力学特性及热动力学特性。应用流体体积(VOF)方法捕获晃动过程中自由表面的波动,使用Lee相变模型来描述晃动过程中的蒸发冷凝现象并与已有试验进行对比验证。研究不同充注水平和晃动条件下液氢的自由表面形状和面积变化,舱壁压力变化,舱罐内气液温度变化以及相变引发的降压现象。结果表明:固有频率附近的晃动伴随着射流和破碎液面的产生,会对舱壁产生抨击压力;液面破碎程度越剧烈,液位越高,舱内压力下降速率越快;舱罐内气液温度演化经历了热分层、晃动混合和总体温升等3个阶段。研究结果对进一步理解非等温低温舱罐中流体的晃动动力学及热力学特性具有重要意义。

案例教学在提高冶金热力学课程教学效果中的运用

冶金热力学是应用热力学的基本原理来研究冶金过程中能量的相互转化及化学反应进行的方向和限度,以及影响反应进行的各种因素,目的在于控制反应向所需要的方向进行。该文通过案例教学措施激发学生对冶金热力学课程的学习兴趣,深化学生对热力学基本理论知识的理解,以提高学生分析和解决实际问题的实践能力,进而提高冶金热力学课程的教学质量和水平。

甘氨酸与热力学抑制剂对甲烷水合物的协同抑制机理

天然气水合物在开采过程中,温度和压力的变化会导致分解后的水合物二次形成,进而会造成井筒和管线堵塞。甘氨酸因其强亲水性和生物可降解性,在水合物防治方面具有巨大应用潜力,但其与热力学抑制剂复配协同抑制水合物生成的作用机理尚不明确。为此,开展了甘氨酸与常见盐类和醇类热力学抑制剂复配使用时的甲烷水合物生成模拟实验,分析了甘氨酸与热力学抑制剂协同抑制甲烷水合物生成机理,并形成了适用于海洋水合物钻探开发用的甘氨酸类钻井液体系。研究结果表明:①甲烷气消耗量并不能真实反映抑制剂对水合物生成的抑制效果,还需结合水合物最终生成量、水合物生成3个阶段的时间变化情况综合判断;②甘氨酸浓度为1.0%时,抑制水合物生成的效果最佳,对应的反应体系具有最小的水合物生成区和最大的稳定区;③相比于单独使用1.0%甘氨酸,5.0%盐类抑制剂与1.0%甘氨酸混合使用时,具有协同抑制水合物生成的效果,可减少水合物生成量20%~30%,但5.0%醇类抑制剂与1.0%以及0.5%甘氨酸混合使用时反而促进了水合物生成;④甘氨酸与盐类混合形成的钻井液体系,可以有效降低水合物生成量。结论认为,该认识进一步厘清了甘氨酸与热力学抑制剂对水合物的协同抑制机理,为解决水合物开采过程中井筒堵塞造成的钻井安全问题提供了实验数据和理论支撑。

考虑表面粗糙度影响的低温涡轮泵特性与动静间隙流动分析

为分析低温涡轮泵过流部件表面粗糙度对其性能特性的影响,阐明表面粗糙度对涡轮泵动静间隙流场的影响机制,选择增材制造闭式叶轮涡轮氧泵为研究对象,在考虑低温介质热力学效应影响的前提下,采用液氮作为增压输送介质,对涡轮泵低温性能开展实验测试和数值计算。研究结果表明:在13 500~26 000 r/min转速范围内,相较于光滑壁面,考虑过流部件表面粗糙度后,采用液氮作为模拟介质得到的涡轮氧泵数值计算结果与实验测试数据吻合较好;随着离心叶轮及蜗壳等主流表面粗糙度从光滑壁面增加至36μm,涡轮氧泵扬程及效率分别下降了9.1%、10.6%;随着动静间隙过流部件表面粗糙度从0增加至20μm,涡轮泵叶轮轴向力合力系数显著降低了25.8%。研究结果对后续深入揭示表面粗糙度对低温涡轮泵动静间隙流场特性影响规律以及过流部件表面质量分区控制具有重要借鉴意义及参考价值。

Elasticity and Thermodynamic Properties of EuS Related to Phase Transition

First-principles calculations of the crystal structures, phase transition, and elastic properties of EuS have been carried out with the plane-wave pseudopotential density functional theory method. The calculated values are in very good agreement with experimental data as well as some of the existing model calculations. The dependence of the elastic constants, the aggregate elastic modulus, and the elastic anisotropy on pressure have been investigated. Moreover, the variation of the Poisson＇s ratio, Debye temperature, and the compressional and shear elastic wave velocities with pressure have been investigated for the first time. Through the quasi-harmonic Debye model, the thermal expansions, heat capacities, Grneisen parameters and Debye temperatures dependence on the temperature and pressure are obtained in the pressure range from 0 GPa to 60 GPa and temperature range from 0 K to 800 K.