Raman spectroscopy study on terephthalamide crystal at high pressures.

In this study, we have investigated the structural stability of terephthalamide (TPA) crystal at pressure from ambient to 15 GPa in the diamond anvil cell at room temperature by Raman spectroscopy. Assignment for the Raman vibration modes of TPA crystal at ambient conditions has been performed based on the density functional theory (DFT) calculations. Pressure-induced structural transition was monitored using in-situ Raman spectroscopy. Remarkable changes (including the appearance of new Raman peaks, disappearance of original Raman bands, discontinuous changes in the pressure dependence of some Raman wavenumbers at different pressures) in Raman spectra were observed at approximately 1.3 and 5.2 GPa, provided clear evidences for two pressure-induced phase transitions: phase I to phase II at ∼1.3 GPa, phase II to phase III at ∼5.2 GPa.

Hydrogen bonding network dynamics of 1,2-propanediol-water binary solutions by Raman spectroscopy and stimulated Raman scattering.

Raman spectroscopy and stimulated Raman scattering (SRS) were used to investigate the hydrogen bonding (HB) network in 1,2-propanediol (1,2-PD)-water binary solutions. Abnormal changes in hydrogen bonds (HBs) were detected when V1,2-PD (volume fraction of the1,2-PD) was 0.4. In the case of Raman spectroscopy, the HB strength of water is weakened and then strengthened with the increase of 1,2-PD volume fraction. In the case of SRS, two new peaks at 3283 cm-1 and 3319 cm-1 were appeared, which demonstrated the appearance of ice-like structures near the methyl group and the weakening of HBs. Based on these phenomena, the HB structure of this binary system underwent a transition from H2O-H2O to H2O-1,2-PD when the V1,2-PD was 0.4 as V1,2-PD increased. This work serves as a reference value for the study of HB networks in alcohol-water binary solutions.

High pressure Raman study of LiClO4.

Lithium perchlorate (LiClO4), as one of the new high-energy oxidizers, is chosen for high pressure Raman research to gain a better understanding of the structure and stability, which is very important for the performance of an explosive. Raman spectra of LiClO4 crystal have been measured from ambient to 25.07 GPa with diamond anvil cells (DACs) at room temperature to investigate the structural stability of this system. Raman vibrational modes of LiClO4 crystal at ambient pressure were resolved comprehensively on the basis of our experimental and calculated results. Upon increase of pressure on LiClO4 crystal sample to 1.96 GPa, it was found that the LiClO4 crystal exhibited a pressure-induced first-order phase transformation behavior. The occurrence of a second phase transformation of LiClO4 crystal induced by pressure was observed at about 5.09 GPa. Both phase transformations were demonstrated based on the detailed spectroscopic analysis of the variations in the number of lattice modes, splitting of Raman bands and frequency jumps of the Raman vibrational modes of LiClO4 crystal.

Electrochemical Activation of Oxygen Vacancy-Rich Nitrogen-Doped Manganese Carbonate Microspheres for High-Performance Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (ZIBs) are considered as one of the ideal devices for large-scale energy storage because of their safety, low cost, and nontoxicity. Unfortunately, the choice of cathode materials for ZIBs is still limited. Herein, a novel oxygen vacancy-rich nitrogen-doped MnCO3 (MnCO3@N) microsphere is reported as a cathode material for rechargeable ZIBs, which displays a relatively high reversible capacity of 171.6 mAh g-1 at 100 mA g-1, outstanding rate performance, and long-term cyclic stability up to 1000 cycles at 1000 mA g-1. The better electrochemical performances of MnCO3@N should be attributed to the introduction of oxygen vacancies in the MnCO3 microcrystal by nitrogen doping, which not only improves the conductivity of MnCO3 microspheres but also creates more active sites for zinc-ion diffusion. In addition, the energy storage mechanism of the MnCO3@N microspheres is systematically investigated. During the initial charge process, the MnCO3@N microspheres are activated to form MnO@N due to the insertion of Zn2+, and partial MnO@N is further oxidized into layered-type MnO2@N, which becomes a part of the active material for subsequent energy storage. This work not only provides a new insight for the ZIB cathode but also deepens the understanding of the energy storage mechanism of carbonate materials.

Dynamically tunable vortex four-wave mixing in a six-level system.

We investigate the orbital angular momentum of vortex light in a six-level atomic system with a closed loop. We find that a vortex light field via four-wave mixing (FWM) is sensitive to the relative phase of the driving fields due to forming a closed loop configuration. Thus, it could periodically tune the phase and intensity of the vortex FWM field by adjusting the relative phase of the driving fields. Moreover, the spatial modulation of the vortex FWM phase and intensity also can be achieved by tuning the intensity of the microwave field and detuning of the driving fields.

An Aromatic Fluoropolymer for Hydrogen Separation from Hydrocarbons.

Plasticization is a critical challenge in membrane-based gas separation. Here a novel fluoropolymer, poly(trifluoro styrene) (PTFS), is reported for hydrogen separation from hydrocarbons. The polymer structure is first characterized by different techniques such as nuclear magnetic resonance (NMR) and positron annihilation lifetime spectroscopy (PALS). Then, gas separation performances of the polymer are studied. The separation of H2 /CH4 is found to outperform most other fluorinated polymers and surpass the Robeson 1991 upper bound. Furthermore, the polymer demonstrates stable or increasing selectivity for hydrogen over hydrocarbons (e.g., CH4 , C2 H6 , and C3 H8 ) at higher pressure, suggesting excellent resistance to plasticization.

Study the effect of Li+ on the ν2/ν3+ν4 Fermi resonance of acetonitrile by Raman Spectroscopy.

Raman spectra of the solution of LiClO4 in acetonitrile (CH3CN) at different concentrations have been measured. With increasing the concentration of Li+, it was noted that several vibrational modes of CH3CN had significant changes in Raman shifts and some new Raman peaks emerged due to the CH3CN⋯Li+ complex formation. In addition, Fermi resonance phenomenon between the ν2' and (ν3 + ν4)' Raman bands of CH3CN⋯Li+ complex was observed. Based on the Bertran's equations, Fermi resonance parameters of free CH3CN and CH3CN⋯Li+ complex at different concentrations have been calculated, respectively. Compared the Fermi resonance coupling coefficients W of free CH3CN with CH3CN⋯Li+ complex at different concentrations, the free CH3CN had a little smaller value, which indicated that the ν2'/(ν3 + ν4)' Fermi resonance in CH3CN⋯Li+ complex was much stronger than the ν2/ν3 + ν4 Fermi resonance in CH3CN. From the detailed analysis of the effect of Li+ on the spectral features of CH3CN, the effect mechanism of Li+ coordination to CH3CN at the nitrogen of the CN group on the ν2/ν3 + ν4 Fermi resonance of CH3CN has been elucidated.

Focal adhesion kinase is overexpressed in thymic epithelial tumors and may serve as an independent prognostic biomarker.

Focal adhesion kinase (FAK) has long been considered to be a key regulator of growth factor receptor- and integrin-mediated signals, with pivotal roles in tumor cells through its kinase activity and scaffolding function. Increased FAK expression and activity has been observed in tumors of various origins and is often associated with a poor prognosis. However, there have been no studies on the aberrant expression of FAK in thymic epithelial tumors to date. The aim of the present study was to evaluate FAK expression in thymic epithelial tumors and to explore the prognostic significance of FAK. FAK expression was investigated in 100 formalin-fixed, paraffin-embedded human thymic epithelial tumor (TET) specimens using immunohistochemical analysis with FAK-specific monoclonal antibody 4.47, and the associations between FAK expression and clinicopathological parameters (including sex, age, tumor size, myasthenia gravis, World Health Organization classification and Masaoka-Koga stage) were analyzed. FAK was significantly overexpressed in TETs compared with in normal thymus tissues (P<0.001). Additionally, FAK overexpression was significantly associated with advanced tumor stages (stages III or IV; P<0.001) and highly aggressive TET subtypes (type B2 and B3 thymomas and thymic carcinomas; P<0.001). Furthermore, FAK overexpression was significantly associated with a worse 10-year overall survival, as determined by univariate analysis (P<0.001). Multivariate analysis revealed that FAK overexpression was an independent prognostic factor for patients with TETs (P=0.034). The results of the present study suggest that FAK serves an important role in the tumorigenesis and progression of TETs. Therefore, FAK may serve as a prognostic biomarker and is a potential therapeutic target for the treatment of TETs.

Pressure-Induced Phase Transition in Weyl Semimetallic WTe2.

Tungsten ditelluride (WTe2 ) is a semimetal with orthorhombic Td phase that possesses some unique properties such as Weyl semimetal states, pressure-induced superconductivity, and giant magnetoresistance. Here, the high-pressure properties of WTe2 single crystals are investigated by Raman microspectroscopy and ab initio calculations. WTe2 shows strong plane-parallel/plane-vertical vibrational anisotropy, stemming from its intrinsic Raman tensor. Under pressure, the Raman peaks at ≈120 cm-1 exhibit redshift, indicating structural instability of the orthorhombic Td phase. WTe2 undergoes a phase transition to a monoclinic T' phase at 8 GPa, where the Weyl states vanish in the new T' phase due to the presence of inversion symmetry. Such Td to T' phase transition provides a feasible method to achieve Weyl state switching in a single material without doping. The new T' phase also coincides with the appearance of superconductivity reported in the literature.

High-pressure Raman study of Terephthalonitrile.

The in situ high-pressure Raman spectra of Terephthalonitrile (TPN) have been investigated from ambient to 12.6GPa at room temperature. All the fundamental vibrational modes of TPN at ambient were assigned based on the first-principle calculations. A detailed Raman spectroscopy analysis revealed that TPN underwent a phase transition at ~5.3GPa. The frequencies of the TPN Raman peaks increase with increasing the pressure which can be attributed to the reduction in the interatomic distances and the escalation of effective force constants. The intensity of the C-C-C ring-out-plane deformation mode increases gradually as the frequency remains almost constant during the compression which can be explained by the existence of π-π interactions in TPN molecules. Additionally, the pressure-induced structural changes of TPN on the Fermi resonance between the C≡N out-of-plane vibration mode and the C-CN out-of-plane vibration mode have been analyzed.

[Effect on Fermi Resonance by Some External Fields: Investigation of Fermi Resonance According to Raman Spectra].

Fermi resonance is a phenomenon of molecular vibrational coupling and energy transfer occurred between different groups of a single molecule or neighboring molecules. Many properties of Fermi resonance under different external fields, the investigation method of Raman spectroscopy as well as the application of Fermi resonance, etc need to be developed and extended further. In this article the research results and development about Fermi resonance obtained by Raman spectral technique were introduced systematically according to our work and the results by other researchers. Especially, the results of the behaviors of intramolecular and intermolecular Fermi resonance of some molecules under some external fields such as molecular field, pressure field and temperature field, etc were investigated and demonstrated in detail according to the Raman spectra obtained by high pressure DAC technique, temperature variation technique as well as the methods we planed originally in our group such as solution concentration variation method and LCOF resonance Raman spectroscopic technique, and some novel properties of Fermi resonance were found firstly. Concretely, (1) Under molecular field. a. The Raman spectra of C5H5 N in CH3 OH and H2O indicates that solvent effect can influence Fermi resonance distinctly; b. The phenomena of the asymmetric movement of the Fermi resonance doublets as well as the fundamental involved is tuned by the Fermi resonance which had not been found by other methods were found firstly by our variation solution concentration method; c. The Fermi resonance properties can be influenced distinctly by the molecular group reorganization induced by the hydrogen bond and anti-hydrogen bond in solution; d. Fermi resonance can occurred between C7 H8 and m-C8H10, and the Fermi resonance properties behave quite differently with the solution concentration; (2) Under pressure field. a. The spectral lines shift towards high wavenumber with increasing pressure, and frequency difference Δ varies with pressure, which induced the change of W; b. The W of νi + ν4 ν3 of CCl4 in C6H6 decreased more quickly in solution than in pure liquid with increasing pressure and the Fermi resonance disappeared ahead of that in pure liquid, which indicates that the phenomenon of Fermi resonance induced by pressure effect can reveal the mechanism of some solvent effects. (3) Under temperature field. a. The Fermi resonance properties of different molecules behave quite differently with temperature. For an instance, the one of CO2 can be influenced distinctly by temperature, while the one of CS2 behaves no change with temperature. This article offers systematic theoretical and experimental support to the investigation of identification and assignment of molecular spectral line, the confirmation of molecular conformation and conformers, the effect of hydrogen bond on molecular structure and properties, etc.

A study on the Fermi resonance of phenol under the effects of pressure and temperature by Raman spectroscopy.

The ν1-ν18a Fermi resonance (FR) of phenol were investigated by pressure-dependent Raman spectroscopy from atmospheric up to P=15.2GPa and temperature-dependent Raman spectroscopy from 40 down to T=-180°C, respectively. In the case of pressure, we found the Fermi coupling coefficient W, which were calculated based on the FR theory, exposed a value turnover between 1.912 and 2.244GPa in the process of increasing the pressure. This turnover phenomenon of the Fermi coupling coefficient W has been ascribed to the crystal structure of phenol evolving towards a more symmetric structure with pressure, from a structure like a pseudo-threefold helical chain at ambient pressure to like a ribbon arrangement at 1.912GPa, then to adopt a herringbone arrangement at much higher pressure. On the other hand, we also found the Fermi coupling coefficient W exhibited monotonic reduction without turnover points appearing by decreasing the temperature. The tendencies of the Fermi coupling coefficient W with temperature were in good agreement with the pressure dependence of the Fermi coupling coefficient W in the region of ambient to 1.912GPa, indicating that the effect of pressure and temperature on the FR of phenol in this region might be the same. A conformation evolving induced by pressure and temperature on the ν1 and ν18a FR of phenol have been analyzed.

Hepatoprotective and antioxidant activities of extracts from Salvia-Nelumbinis naturalis against nonalcoholic steatohepatitis induced by methionine- and choline-deficient diet in mice.

BACKGROUND: Nonalcoholic steatohepatitis (NASH), the advanced stage of nonalcoholic fatty liver disease that is characterized by both steatosis and severe injury in liver, still lacks efficient treatment. The traditional Chinese formula Salvia-Nelumbinis naturalis (SNN) is effectively applied to improve the symptoms of nonalcoholic simple fatty liver (NAFL) patients. Previous studies have confirmed that SNN could reduce the liver lipid deposition and serum transaminases of NAFL experimental models. This study aims to determine whether SNN is effective for murine NASH model and investigate the underlying pharmacological mechanisms. METHODS: C57BL/6 J mice were fed with methionine- and choline-deficient (MCD) diet for six weeks to induce NASH. Simultaneously, SNN or saline was intragastrically administered daily to the mice in the SNN or model group, respectively. A standard diet was given to the control mice. Serum biochemical indices and tumor necrosis factor-α were measured. Liver histopathology was observed, and the contents of triglycerides and lipid peroxide malondialdehyde (MDA) in liver homogenates were evaluated. The hepatic expression and/or activation of genes associated with inflammation, apoptosis, and oxidative stress were determined by quantitative RT-PCR or Western blot analysis. RESULTS: The prominent liver steatosis displayed in the NASH model was prevented by SNN. The liver injury of NASH mice was obviously manifested by the increased levels of serum transaminases and bilirubin, as well as the lobular inflammation, elevated pro-inflammatory cytokines, and upregulated apoptosis in liver tissues. SNN administration improved the aforementioned pathological changes. The increased hepatic levels of MDA and cytochrome P450 2E1 of the model confirmed the unregulated balance of oxidative stress. The hepatic expression of nuclear factor erythroid 2-related factor 2 and its target genes decreased, whereas c-Jun N-terminal kinase activation in the model mice increased. Treating the mice with SNN significantly improved oxidative stress-related harmful factors. CONCLUSIONS: This study shows that SNN can protect the liver from severe steatosis and damage induced by MCD diet, which suggests the potential use of SNN on the treatment of NASH patient. The results also indicate that improving the hepatic antioxidant capability of the liver may contribute to the underlying hepatoprotective mechanism.

Raman spectra from symmetric hydrogen bonds in water by high-intensity laser-induced breakdown.

Raman spectra of ice VII and X were investigated using strong plasma shockwave generated by laser-induced breakdown (LIB) in liquid water. Simultaneously, the occurrence of the hydrogen emission lines of 656 nm (Hα), 486 nm (Hß), 434 nm (Hγ) and 410 nm (Hδ) was observed. At 5 × 10(12) W/cm(2) optical power density, the O-H symmetric stretching, translational and librational modes of ice VII and a single peak at 785 cm(-1) appeared in the spectra. The band was assigned to the Raman-active O-O mode of the monomolecular phase, which was the symmetric hydrogen bond of cuprite ice X. The spectra indicated that ice VII and X structure were formed, as the trajectory of the strong plasma shockwave passes through the stable Pressure-Temperature range of ice VII and X. The shockwave temperature and pressure were calculated by the Grüneisen model.

Chinese medicine formula lingguizhugan decoction improves Beta-oxidation and metabolism of Fatty Acid in high-fat-diet-induced rat model of Fatty liver disease.

Lingguizhugan decoction (LGZG), a classic traditional Chinese medicine (TCM) formula, has been used to treat obesity and hyperlipidemia in recent years, but the related mechanisms underlying the regulation of lipid metabolism by LGZG are not clear yet. Here, we reported the effectiveness and possible mechanisms of LGZG on rats with fatty liver disease induced by high-fat diet (HFD). Our results demonstrated that LGZG significantly attenuated HFD-induced fatty liver disease, as measured by body weight, liver index, epididymal fat pad-body weight ratio (EFP/BW), liver injury, and hepatic triglycerides (TG) probably through increasing serum thyroid hormone levels, improving beta-oxidation (via modulation of TR ß 1 and CPT1A expression), metabolism and transport (through modulation of SREBP-1c, ACSL and ApoB100 expression) of fatty acid. In addition, we discovered the herbal combination with the properties of warming yang to relieve water retention in the formula and proposed the biological basis of LGZG conventional effect via further study on disassembled formula. This study, for the first time, revealed the mechanisms through which LGZG regulates lipid metabolism. Furthermore, our study suggested that it might be feasible to understand the scientific implications of TCM from the perspective of classic formulas' conventional efficacy.

Stimulated Raman scattering from sulfur-II produced by laser decomposition of liquid carbon disulfide.

Stimulated Raman scattering (SRS) of sulfur-II (S-II) phase was investigated by laser decomposition of liquid carbon disulfide. As a matter of fact, above a threshold of the laser intensity, it is suggested that a strong shock wave is generated in the liquid carbon disulfide, which is decomposed owing to the induced high dynamic pressure and temperature. One bending mode E frequency at 289 cm(-1) and one symmetric stretching mode A1 frequency at 490 cm(-1) of S-II phase were observed. The SRS spectra indicated that S-II structure is formed by laser decomposition, as the strong shock wave generates the stable pressure-temperature range of S-II phase. The dynamic high-pressure and static-electric field generated by laser-induced breakdown results in the softening A1 mode becoming more hardened.

[Comparative study on the effects of different therapeutic methods in preventing and treating nonalcoholic fatty liver in rats].

OBJECTIVE: To explore the pathogenesis of nonalcoholic fatty liver (NAFL) in traditional Chinese medicine (TCM) by comparing the therapeutic efficacy of methods for fortifying the spleen and replenishing qi, warming yang and fortifying the spleen and warming yang to move water. METHODS: Male Wistar rats were randomly divided into normal, model, Sijunzi Tang (SJZ), Lizhong Tang (LZ), Linggui Zhugan Tang (LGZG) and Shenzhuo Tang (SZ) groups. Rats in the normal group were fed with ordinary diet, while the rats in the other groups were fed with high fat diet including 88% ordinary food, 10% lard oil and 2% cholesterol. After four weeks of treatment, the weight of liver and epididymal fat was recorded respectively for calculating the indexes of liver (liver weight/body weight) and epididymal fat (weight of epididymal fat pads/body weight); the pathological changes in liver tissues were observed by hematoxylin and eosin (HE) staining; the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), triacylglycerol (TAG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and very-low-density lipoprotein cholesterol (VLDL-C) and liver TAG concentration were analyzed by biochemical test. RESULTS: Body weight, liver and epididymal fat indexes and liver TAG level of rats all significantly increased in the model group as compared with the normal group (P<0.05). Hepatic fatty infiltration, TAG concentration and the levels of serum TAG and ALT were significantly decreased in the LGZG and SZ groups when compared to those in the model group (P<0.05). In addition, epididymal fat index and serum TC level also significantly decreased in the LGZG group as compared with the model group (P<0.05). However, there was no significant change in liver TAG concentration in LZ and model groups. CONCLUSION: Method of warming yang or moving water can promote the lipid metabolism. It may be an effective strategy in preventing and treating NAFL by treating with warming yang and moving water together.

Raman spectroscopy study on the ν1-2ν2 Fermi resonance of liquid carbon disulfide in binary solutions: effect of the weak hydrogen bond formation on the Fermi resonance.

We have measured the Raman spectra of liquid CS(2) at different volume concentrations in CHCl(3) and CH(2)Cl(2) solutions. With decreasing the volume concentration of CS(2), a noticeable growth in the 2ν(2) band frequency was observed, while the ν(1) band location remained practically unchanged. This asymmetric wavenumber shift phenomenon of the Fermi doublet ν(1) and 2ν(2) of CS(2) has been ascribed to weak, non-conventional hydrogen bonds formed between the CS(2) and the solvent molecules. These weak hydrogen bonds were also responsible for significant decreases in the C-H bond symmetric stretching vibration band frequencies of CHCl(3) and CH(2)Cl(2). The values of the ν(1)-2ν(2) FR parameters of CS(2) in CH(2)Cl(2) and CHCl(3) at different volume concentrations were calculated according to the FR theory. The magnitude of the FR coupling coefficient W of CS(2) increases upon dilution with CH(2)Cl(2) and CHCl(3), indicating that the vibrational anharmonicity is relatively sensitive to variations in the weak hydrogen bonding. Compared with the changing tendencies of Fermi coupling coefficient W of CS(2) in CH(2)Cl(2) and CHCl(3) at different volume concentrations, we discussed the effect of the weak hydrogen bond formation on the FR and the asymmetric wavenumber shift phenomenon of the Fermi doublet ν(1) and 2ν(2) of CS(2).

[Effects of the mixture of Swertia pseudochinensis Hara and Silybum marianum Gaertn extracts on CCl(4)-induced liver injury in rats with non-alcoholic fatty liver disease].

OBJECTIVE: To study the mechanism of liver injury induced by carbon tetrachloride (CCl(4)) in rats with non-alcoholic fatty liver disease (NAFLD), and the therapeutic effects of the extract mixture of Dangyao (Swertia pseudochinensis Hara) and Shuifeiji (Silybum marianum Gaertn) on NAFLD rats with liver injury. METHODS: Male Wistar rats were randomized into normal control group, CCl(4) group, high-fat diet group, high-fat diet plus CCl(4) injection group (model group), diammonium glycyrrhizinate group and extract mixture group. Except the normal control and CCl(4) groups, rats were fed with high-fat diet (88% normal chow, 10% lard and 2% cholesterol) to induce NAFLD. Diammonium glycyrrhizinate and extracts were given by gavage. After eight weeks, a nonlethal dose of CCl(4) was injected intraperitoneally to all rats except the normal and high-fat diet groups. And 48 h later, all rats were sacrificed, and serum and liver tissues were collected for further study. Paraffin-processed liver tissue was stained with hematoxylin-eosin (HE) to observe the pathological changes. Serum alamine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. The levels of triacylglycerol (TAG), malondialdehyde (MDA) and glutathione (GSH) in liver tissues were also examined. Expression of uncoupling protein 2 (UCP2) was determined by reverse transcription-polymerase chain reaction and Western blotting. RESULTS: Liver sections stained with HE showed that the histopathological changes in the normal control group and the CCl(4) group were mild; massive hepatosteatosis diffusing in lobules was shown in the high-fat diet groups; steatosis, hepatocellular ballooning degeneration and inflammatory infiltration were severe around the central vein in sections of the model group. Compared with the model group, hepatosteatosis and ballooning were significantly attenuated in the treatment groups. Levels of serum ALT and AST, contents of TAG and MDA and the UCP2 expression in liver tissues of the model group increased obviously, while the level of liver GSH decreased. Compared with rats in the model group, the above biomarkers in the treatment groups were improved significantly. CONCLUSION: The mixture of Dangyao and Shuifeiji extracts can decrease the susceptibility and degree of liver injury induced by hepatotoxin in rats with NAFLD. Regulation of the balance of pro- and anti-oxidative stress factors is involved in the mechanism.

The effect of the Fermi resonance on the Raman scattering cross sections of the Fermi doublet ν1 and 2ν2 of liquid carbon disulfide in benzene.

The effect of the Fermi resonance (FR) on the Raman scattering cross sections (RSCSs) of the Fermi doublet ν1, 2ν2 of liquid CS2 in C6H6 using the method of changing the volume concentration of the solution is investigated. We have calculated the RSCSs of the Fermi doublet ν1, 2ν2 using Onsager's theory with the 992 cm(-1) Raman line of C6H6 as the internal standard. The result shows that the RSCS of the ν1 line decreases with decreasing the volume concentration of CS2, while that of the 2ν2 line unexpectedly increases. With decreasing the volume concentration of CS2, two main effects of the solvent effect (SE) and the FR in binary solution that can make the ν1, 2ν2 RSCSs change: the SE, as calculated, reduces both the ν1 and 2ν2 RSCSs; the FR plays a significant role in reducing the ν1 RSCS and enhancing the 2ν2 RSCS. In comparison with our previous investigation [J. Raman Spectrosc. 41 (2010) 776-779], it was found that the stronger the FR is, the more the RSCS of the ν1 decreases and the 2ν2 increases. Thus, we proposed that the result can be best explained by taking into account the effect of the FR on the RSCSs of the Fermi doublet. In addition, this paper also gives an explanation to the experimental results deviating from the theoretical results of the scattering coefficients of CS2 in solvent C6H6 as mentioned in Fini's paper.