[A Simple but Effective Device to Avoid Objective Lens Overheating: An Air Blower Device].

The interior of the Earth is a high temperature and high pressure environment. High temperatures cause important changes in the physical and chemical properties of minerals. An increase in temperature leads to significant changes in the molecular and lattice vibrations, elasticity, and seismic velocity of minerals.

[Raman Spectroscopic Study on the Determination of SO4(2-) Concentration in Aqueous Solution under High Temperature and Pressure].

In the present work, the Raman spectra of SO4(2-) ions in aqueous solutions were studied. The quantitative analysis shows that there is a significant correlation between the Raman intensity ratio(R) and the SO4(2-) concentration. The SO4(2-) concentration in aqueous solution at ambient temperature and pressure can be determined by the Raman intensity according to the linear fitting equation c (SO4(2-) = 4.

Raman spectroscopic quantitative study of NaCl-CaCl2-H2O system at high temperatures and pressures.

Raman spectra features of the ternary system NaCl-CaCl2-H2O under high temperatures and high pressures were systematically studied in the present work by using hydrothermal diamond anvil cell (HDAC) and Raman shifts of quartz to determine pressures, and it has been obtained for the quantitative relationship between Raman shifts of the O-H stretching band of water, mass fractions of solutes and pressures was obtained. The mass fractions of salts, where salinity of NaCl equal to that of CaCl2, are 4.0 mass %, 8.

[Research on Raman spectra of chalcopyrite under 0-1400 MPa and ambient temperature].

The variation characters of the A1 mode Raman spectra of chalcopyrite under 0.1-1400 MPa and ambient temperature were researched using diamond anvil cell. The results show that the shape and intensity of the Raman peak remains constant under experimental conditions, indicating that the chemical bounds of Cu-S and Fe-S remain unchanged.

[Research on Raman spectra of isooctane at ambient temperature and ambient pressure to 1. 2 GPa].

The experimental study of the Raman spectral character for liquid isooctane (2,2,4-trimethylpentane, ATM) was con ducted by moissanite anvil cell at the pressure of 0-1.2 GPa and the ambient temperature. The results show that the Raman peaks of the C-H stretching vibration shift to higher frenquencies with increasing pressures.

[Raman spectroscopic study on the fluid effects in dissolution and phase transition mechanisms of gypsum].

Raman spectroscopic studies on the process of dissolution and phase transition of gypsum in different fluids were taken. Gypsum took phase transition to be anhydrite in the range from 170 degrees C to 190 degrees C in pure water, and no more change happened with decreasing temperature to room temperature. Gypsum took phase transition to be anhydrite in the range from 170 degrees C to 190 degrees C too in Na2 SO4 solution, but anhydrite can regain to be gypsum when temperature decreases to room temperature.

[Research on Raman spectra of oxalic acid during decarboxylation under high temperature and high pressure].

The present research studied the thermal stability of oxalic acid under high temperature and pressure and its in-situ transformation by Raman spectroscopy using a hydrothermal diamond anvil cell. Raman spectra allow the detection of ionic and covalent atomic aggregates through the acquisition of vibrational spectra that are characteristic of their structures and molecular bond types. The result showed that there was no change in characteristic vibrational Raman peaks of oxalic acid in the low-temperature stage.

[In situ experimental study of phase transition of calcite by Raman spectroscopy at high temperature and high pressure].

The phase transitions of calcite at high temperature and high pressure were investigated by using hydrothermal diamond anvil cell combined with Raman spectroscopy. The result showed that the Raman peak of 155 cm(-1) disappeared, the peak of 1 087 cm(-1) splited into 1083 and 1 090 cm(-1) peaks and the peak of 282 cm(-1) abruptly reduced to 231 cm(-1) at ambient temperature when the system pressure increased to 1 666 and 2 127 MPa respectively, which proved that calcite transformed to calcite-II and calcite-III. In the heating process at the initial pressure of 2 761 MPa and below 171 degrees C, there was no change in Raman characteristic peaks of calcite-III.

[Research on Raman spectra of calcite phase transition at high pressure].

The present research studied the process of phase transition from calcite-I to calcite-III under the condition of high hydrostatic pressure using hydrothermal diamond anvil cell and Raman spectrum technique. The hydrothermal diamond anvil cell is the most useful instrument to observe sample in-situation under high temperature and high pressure. The authors can get effective results from this instrument and pursue further research.

[Raman spectra study of barite at the pressure of 0-1 GPa and ambient temperature].

The variation characters of Raman spectra of S-O symmetric stretching vibration v987 and symmetric bending vibration v452 and V462 of barite at high pressure were studied using moissanite anvil cell. The experimental results show that barite is stable at the pressure of 0-1 GPa and ambient temperature, and the Raman peak positions of barite shift to higher frequency with increasing pressure. The relations between the Raman shifts and system pressure are given as follows: v987 = 0.

[Research on the experiment of hydrogen isotope fractionation using diamond anvil cell and Raman spectra].

Hydrothermal diamond-anvil cell and Raman spectroscopy were used to measure the hydrogen isotope fractionation factor between gypsum and liquid water. Hydrogen isotopes of deuterium (D) and hydrogen (H) show the largest relative mass difference in all stable isotope systems. The exchange reaction between D and H would easily take place and the extent of exchange would be larger than others under same condition.

[Raman spectra of aragonite at the pressure of 0.1-2 GPa and ambient temperature].

Raman spectra of aragonite were studied at ambient temperature and pressure of 0.1 - 2 GPa in a moissanite anvil cell using Raman spectrum technique. The relations between the Raman shifts of aragonite and the system pressure are given as follows: v153 (cm(-1)) = 0.

[Study on the accuracy of pressure determined by raman spectra of quartz].

Quartz as a pressure gauge and its accuracy were studied by Raman spectroscopy at 25 degrees C and ambient pressure. The result shows that even at same temperature and pressure, the Si-O vibrational mode for different grains of quartz varies between 463.59 and 464.

[In-situ research on Raman spectroscopy of 1-pentanol under high pressure].

Raman spectra in 800-3 000 cm(-1) of 1-pentanol were studied under high pressure and at ambient temperature (23 degrees C) using a cubic zirconia anvil cell. The Raman peaks become sharper at higher pressure so that each individual C-H stretching mode is difficult to be distinguished. The Raman frequencies of the C-H stretching modes shift to a higher position with increasing pressures ranging between 0.

[Research on Raman spectra of benzoic acid during decarboxylic process].

The present research studied benzoic acid change in water and its Raman spectra in temperature rising period using hydrothermal diamond anvil cell and Raman spectrum technique. The hydrothermal diamond anvil cell is the most useful instrument to observe sample in-situation under high temperature and high pressure. The authors can get effective results from this instrument and pursue further research.

[Evidence of discontinuities in the Raman spectra of aqueous NaCl solution at high pressure].

In-situ Raman spectra measurement for aqueous NaCl solution was conducted at the temperature of 21 degrees C and the pressures of 50-1 100 MPa using a SiC anvil cell. It is shown that the decomposed bands of aqueous NaCl solution shift to lower wavenumber with increasing pressure initially and reaches the minimum at about 300 MPa, and increases at higher pressure up to about 800 MPa, then decreases again with increasing pressure. Similarly, the ratio of band-area and the width at half maximum of the decomposed bands of the solution exhibit discontinuities at about 300 and 800 MPa.

[Research on Raman spectra of heavy water at high pressure].

The present work studies the Raman spectra of heavy water at pressure from 0.1 MPa to 800 MPa at ambient temperature using the method of diamond anvil cell and Raman spectrum technique. The result shows that the Raman peak of heavy water moves to lower frequency, and the linear relationship exists between Raman shift and pressure.

[Raman spectra of carbonate ions as pressure gauge at high pressure and room temperature].

Three aqueous solutions of sodium carbonate (1.5, 2.0 and 2.

[Research on Raman spectra of 2-methylpentaneat at pressure of 0-1.5 GPa and temperature of 26 degrees C].

The present paper investigates the Raman spectral character of liquid 2-methylpentane by an experiment at the pressure of 0-1.5 GPa and the temperature of 26 degrees C, and defines the relation between the pressure and the Raman peak of 2-methylpentane at ambient temperature. The result shows that there are five characteristic Raman peaks in 2-methylpentane defined as v (CH2) and v(CH3), and all of them move to high position as the system pressure increases.

[Raman spectroscopic studies of n-pentadecane under high temperature].

The present paper investigates the Raman spectrum of n-pentadecane in diamond anvil cell under a temperature up to 350 degrees C. The result shows that the pressure increases at elevated temperature, but the effect of pressure on the stretching vibrational modes of CH3 and CH2 is inverse to that of temperature. The action of temperature is weaker than that of pressure.

[Research on Raman spectra of glycerinat at the pressure of 0-1.0 GPa and the temperature of 29 degrees C].

The present paper investigates Raman spectral characters of liquid glycerin by the experiment at the pressure of 0-1.0 GPa and the temperature of 29 degrees C, and defines the relation between the pressure and the Raman peak of glycerin at ambient temperature. The result shows that there are two characteristic Raman peaks of glycerin defined as v(CH) and v(CH2), and both of them move to higher positions as system pressure increases.

[Structural studies on methanol up to 563 K under pressure].

This paper investigates the structure of methanol by Raman spectrum in diamond anvil cell up to 563 K. The result shows that pressure increases at elevated temperature, but the effect of pressure on the stretching vibrational modes of C-H is inverse to that of temperature. The action of temperature is weaker than that of pressure.

[Experimental study of Raman spectra of magnesite at 297 K and at the pressure of 0.13-1 GPa].

The experimental study of Raman spectra of magnesite has been conducted at the pressure of 967 MPa and at the temperatureof 297 K using a cubic zirconia-anvil cell. The result shows that neither phase transition nor organic substances were observed during compression, and the Raman peak of magnesite shifted to higher frequency with increasing pressure. The relation between the pressure and the Raman peak position of magnesite (1094 cm(-1)) was obtained as follows: v (cm(-1)) = 0.

[The study of raman spectra for ethanol under the pressures of 0.1-900 MPa at 24 degrees C].

Experimental measurement and study of Raman spectra for pure ethanol and 50% ethanol aqueous solution has been conducted at ambient temperature and the pressures of 0.1-900 MPa by using Cubic Zirconia anvil cell. The result shows that the frequency of C-H stretch vibration increases with increasing pressure and each of their relation between the frequency and pressure can be expressed as following: for pure ethanol: v1 = 2881.

[Applications of moissanite anvil cell for Raman spectroscopy under high-temperature and high-pressure].

This paper introduces the structure and the feature of moissanite anvil cell, which is composed of moissanite anvil, supporting and creating pressure system, heater system and metal gasket. Because of its high hardness, high heat conductance, low thermal expansion, good thermal stability and low price, moissanite is a good material of anvil for high-temperature and high-pressure experimental studies. With this cell, the Raman spectrum of sodium carbonate solution, sodium sulfate solution and distilled water has been in situ measured under high-temperature and high-pressure.