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Yes-associated protein (YAP), as a co-activator of transcription factors, is a downstream protein in the Hippo signaling pathway with important functions in cell proliferation, apoptosis, invasion and migration. YAP also plays a key role in the development of CCl4-induced liver fibrosis. However, the mechanism of YAP during hepatic fibrosis progression and reversion is still unclear. Mild liver fibrosis was developed after 4 months of high-fat diet (HFD) stimulation, and we found that the YAP signaling pathway was activated. Here, we aim to reveal whether specific knockout of Yap gene in the liver can improve liver fibrosis induced by insulin resistance (IR) stimulated by HFD, and further explain its specific mechanism. We found that liver-specific Yap gene knockout improved IR-induced liver fibrosis and liver dysfunction, and this mechanism is related to the inhibition of the insulin signal pathway at the FoxO1 level. These findings provide a new insight, and Yap is expected to be a new target to reverse the early stage of liver fibrosis induced by IR.

The adventitious carbon located at 284.8 eV was used to calibrate samples without the carbon themselves. When the carbon is as a major part of the inorganic material, the adventitious carbon should be identified and used as the reference. There is no adventitious carbon on the surfaces of the polymer materials, so using C1s of the carbon in the polymer itself to calibrate the charging effect is reasonable. Furthermore, compared with gold and argon, a more practical and convenient method based on C1s is proposed to get the right positions for binding energy peaks.

Layered double hydroxides (LDHs) with the physical property of high ultraviolet (UV) reflectance were used to enhance the anti-UV aging performance of bitumen. In view of the poor compatibility of LDHs with bitumen, three organic anions, namely, sodium dodecyl benzenesulfonate (SDBS), sodium dodecyl sulfate (SDS) and sodium dodecyl sulfonate (SDSO), were used as modifiers to prepare organic LDHs (OCLDHs) through regeneration process, and the crystal structure, chemical composition, morphological feature and UV shielding capability of synthesized OCLDHs were analyzed. Then the OCLDHs were added into bitumen to evaluate the storage stability and anti-UV aging property of OCLDHs/bitumen composites. The results show that the organic anions are inserted into the interlayers of LDHs, the intercalation expands the interlayer distance of LDHs, makes the particle shapes become more irregular and complicated, and enhances the absorption ability within the range from 200 to 300 nm while has little influence on the UV reflection ability. Result of high temperature storage stability indicates the organic modification ameliorates the compatibility of LDHs with bitumen. Compared with LDHs, OCLDHs decrease the deteriorations of bitumen's properties during UV exposure test, exhibiting better effect in enhancing anti-UV aging performance of bitumen. Furthermore, among the three OCLDHs, LDHs intercalated by SDBS exhibit the most effective improvement due to the best compatibility with bitumen and comparatively good UV shielding effect.

The viscous-elastic behavior, noise reduction and viscosity-temperature susceptibility of aged SBS modified asphalt (SBSMA) incorporated with fluid catalytic cracking slurry (FCC) and Trime...

Layered double hydroxides (LDHs) with different particle sizes (75 nm, 115 nm, 180 nm and 300 nm which were marked with LDHs-75, LDHs-115, LDHs-180 and LDHs-300) were characterized by scanning electron microscope, UV–vis reflection and absorption spectrophotometer and laser scatter meter. Furthermore, this paper investigated the influence of LDHs with different particle sizes on the rheological properties of bitumen before and after ultraviolet aging by temperature susceptibility test, dynamic shear rheometer test (DSR) and IR spectra test (FTIR). The researches reveal that LDHs-180 hold the strongest UV shielding performance. The temperature susceptibility of pristine bitumen and LDHs-75, LDHs-115, LDHs-180, LDHs-300 modified bitumen after aging decreased by 9.01%, 6.36%, 3.98%, 2.15% and 5.49%, respectively, which indicate LDHs-180 is more beneficial to weaken the decrease of bitumen temperature susceptibility after aging. Similarly, LDHs-180 modified bitumen show less variation in rheological properties than other bitumen samples after aging. This implies that LDHs-180 could mitigate the influences of UV aging on the rheological properties of bitumen more availably. In addition, the FTIR analysis further shows that the carbonyl and sulfoxide index of LDHs-180 modified bitumen is the smallest after aging, which indicates LDHs-180 is more helpful for improving bitumen anti-UV aging properties than that of LDHs-75, LDHs-115 and LDHs-300.

Layered double hydroxides (LDHs) have been alternatively employed to improve the ultraviolet (UV) aging resistance of bitumen due to their high UV reflectance, but LDHs particles cannot be dispersed into bitumen uniformly and stably since their poor compatibility with bitumen. Therefore, the problem of poor compatibility must be solved before its application. Generally, organic modification can change the surface characteristics of inorganic particle and then improve the compatibility. The objectives of this work are to evaluate the effect of prepared various organic LDHs on the anti-UV aging property of bitumen and then determine an optimal organic LDHs for bitumen modification. For these purposes, three organic anions, sodium dodecyl benzenesulfonate (SDBS), sodium dodecyl sulfate (SDS) and sodium dodecyl sulfonate (SDSO), were used as organic modifiers to prepare organic LDHs (OCLDHs), then the storage stability and anti-UV aging of OCLDHs modified bitumen were investigated. Experimental results show the organic modification can suppress the separation phenomenon of OCLDHs modified bitumen during the high temperature storage, indicating the compatibility and stability of the mixture is ameliorated. Compared with LDHs modified bitumen, OCLDHs modified bitumens show lower aging degree during UV exposure, which indicates that OCLDHs exhibit better effect in enhancing the anti-UV aging performance of bitumen. FTIR analysis indicates that OCLDHs effectively retard the formations of oxygen-containing functional groups and aromatic structure of bitumen. Furthermore, SDBS is a preferable modifier for the preparation of organic LDHs due to the most effective improvement in compatibility with bitumen and UV aging resistance of bitumen as compared with SDS and SDSO.

The excellent comprehensive performance of SBS modified bitumen (SMB), during a long-term thermo- and photo-oxidative exposure, will fail to satisfy the pavement requirement. In this paper, the synergistic effect of 4,4′-diphenylmethane diisocyanate (MDI) and 1,4-butanediol diglycidyl ether (BUDGE) on the molecular weight of aged SBS was firstly studied, through a simulation, to confirm whether a new polymer structure can be obtained. Then, the reactive rejuvenating system containing MDI, BUDGE and bituminous composition returning agent (MDI-BUDGEs) was applied in the rejuvenation of aged SMB. The results show that the rebuilt molecular structure of aged SBS can be obtained with the combination of MDI and BUDGE. Meanwhile, MDI-BUDGEs can improve the low-temperature ductility and inhibit the sharp fall of the softening point of aged SMB, while decrease the viscosity-temperature response at 120–165 °C. Also, MDI-BUDGEs can contribute for increasing the viscous component, improving the fatigue resistance and remaining the high-temperature performance grade of aged SMB, and moreover, decrease the limited elastic modulus and the elastic-plasticity transition rate to avoid the occurrence of the brittle failure within a small strain range.

Layered double hydroxides (LDHs) etched by nitric acid was characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), zeta potential potentiometer, scanning electron microscopy (SEM) and ultraviolet and visible (UV–Vis) spectrum. TEM suggests that etching treatment causes the formation of some defects on the surface of etched LDHs and XPS shows that some hydroxyl groups are eliminated from the surface of LDHs after etching. The zeta potential of LDHs is enhanced from 12.02 mV to 17.21 mV for etched LDHs, which suggests etching treatment of LDHs can enlarge repulsion force between particles of LDHs. SEM confirms that the etching treatment is helpful to reduce the agglomeration of LDHs. UV–Vis curves indicates that the absorption UV capacity of LDHs is significantly improved by etching treatment. Moreover, the impact of etching treatment on the physical properties and dynamic rheological characteristics of LDHs modified bitumen during the process of aging was thoroughly investigated. Investigation results indicate that the etching treatment of LDHs is favorable for improving the ductility of LDHs modified bitumen. And the etched LDHs modified bitumen shows the smaller variations of physical properties and dynamic rheological properties as well as structural indexes after UV aging than those of LDHs modified bitumen, revealing that etched LDHs is more beneficial to enhance the anti-ultraviolet aging properties of bitumen since the improvement of dispersity and UV shielding capability of LDHs after etching.

This paper mainly investigates the effect of the reactive rejuvenator diphenyl methane diisocyanate (MDI) and 1,4-butanediol diglycidyl ether (BUDGE) on chemical structures of aged SBS and rejuvenated structures, rejuvenation mechanisms, physical and rheological properties of UV-aged SBS modified bitumen (SMB). Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) show the hydroxyl and carbonyl groups have formed on aged SBS, which indicates that the broken-chain structures of SBS have formed after UV radiation. Meanwhile, the disappeared hydroxyl groups and formed amide bond in FTIR spectrum of MDI rejuvenated SBS, and the associated hydroxyl groups and another appeared carbonyl groups in FTIR spectrum of BUDGE rejuvenated SBS indicate MDI and BUDGE can act as a “bridge” to connect the broken-chain SBS together at 150 °C. Moreover, the performance results show rejuvenation temperature and time have little impact on the physical properties of rejuvenated SMB whatever the rejuvenator is selected. With the increasing content of MDI, the softening point of rejuvenated SMB can be improved and the ductility at low temperature remains almost unchanged. However, the softening point of rejuvenated SMB decreases and the ductility increases as the rising content of BUDGE. Phase angle results indicate MDI can further increase the elasticity of aged SMB, and BUDGE can to some extent restore the viscosity characteristic. From the results of fatigue and rutting performance, 1% BUDGE weakens the fatigue limit temperature of aged SMB from 20.1 °C to 14.9 °C and 1% MDI increases the rutting limit temperature from 79.6 °C to at least 80 °C, which indicates BUDGE and MDI can respectively help improve the fatigue resistance and rutting resistance. Based on the analysis of FTIR spectra and the relative functional group indexes, the results show the increasing concentration of I NH CO in MDI rejuvenated SMB and I C O C in BUDGE rejuvenated SMB, indicating the chemical reaction between reactive rejuvenators and aged SMB can be occurred. The rejuvenation of aged SMB with MDI or BUDGE abides by the addition reaction mechanism or condensation reaction mechanism.

To cater for the concept of global green development, it is of importance, in the bituminous road domain, to achieve the objective of the high-quality rejuvenation of waste bitumen. This paper investigates physical properties, rheological properties, morphology and molecular structure of rejuvenated SBS modified bitumen (SMB) with 1, 4-butanediol diglycidyl ether (BUDGE) or trimethylolpropane triglycidyl ether (TMPGE). The results of physical properties indicate that BUDGE and TMPGE can both improve the low-temperature ductility and penetration of aged SMB, and by contrast, BUDGE can make the aged SMB more flexible at low temperature. From the rheological properties, BUDGE or TMPGE can help restore the crack resistance at low temperature and somewhat decrease the rutting resistance at high temperature, which relies on the reduction of fatigue factor and rutting factor of aged SMB. FTIR spectra and fluorescence images show that the original structure of SBS can be partly rebuilt through the chemical reaction between the terminal groups on BUDGE or TMPGE and the oxygen-containing reactive groups on degraded SBS.

This paper investigated the ageing behaviour of bitumen modified with organically modified layered double hydroxides (LDH). Two organo-LDHs (OLDHs) intercalated by different UV absorbents, 2-hydrox...

The effects of five layered double hydroxides (LDHs) with different zinc ratio on the physical and rheological properties, chemical components, and anti-UV aging performance of asphalt were evaluated. Results show that LDHs improve the deformation resistance of asphalt at high temperature. After UV aging, LDH-modified asphalts show the smaller changes of physical and rheological properties and chemical components in comparison with asphalt, indicating the improved UV aging resistance. By comparison, the LDHs with higher ratio of zinc in the layers have the more outstanding UV reflection ability, leading to a beneficial effect in improving UV aging resistance of asphalt.

Triethoxyvinylsilane surface organic modified layered double hydroxides (TEVS-LDHs) were prepared and applied to improve the ultraviolet aging resistance of bitumen. The effect of TEVS-LDHs and LDHs on the temperature susceptibility and rheological properties of bitumen before and after UV aging were thoroughly investigated. The storage stability test showed that the difference in the softening point (ΔS) of LDHs modified bitumen (the LDHs content at 2%) decreased from 1 °C to 0.4 °C after TEVS surface organic modification, and the descending trend was more obvious with the content of LDHs increase, which implied that TEVS-LDHs dispersed better and existed more stably in bitumen than LDHs. The introduction of TEVS-LDHs significantly alleviated the temperature susceptibility of bitumen and increased the rutting factor (G ∗ /sin δ) of bitumen, indicating that TEVS surface organic modification were favorable to the improvement of high-temperature performance for LDHs modified bitumen. After UV aging, bitumen became more hard and brittle, compared with LDHs, the addition of TEVS-LDHs alleviated obviously the deterioration tendency of bitumen, which suggested that LDHs surface organic modified by TEVS were far superior to unmodified LDHs in enhancing the UV aging resistance of bitumen.

Ion chelator is a novel crystalline additive which can chelate Ca2+ and migrate in concrete to promote self-healing of surface crack and internal pore. In order to further explore the effect of ion chelator on hydration process of cement, the hydration heat, chemically bound water, compressive strength, hydration products, pore-size distribution and microstructure of cement paste with ion chelator were investigated in this paper. Results of the experiments showed that the ion chelator accelerated the hydration of the cement paste. Incorporation of ion chelator in cement greatly enhanced the chemically bound water content and the mechanical property. Compared with control cement paste, the chemically bound water content and compressive strength of cement paste with 0.5 wt% ion chelator increased by 13.3% and 16.8% after curing for 28 days. According to the DTA-TG and XRD tests, the ion chelator can promote the hydration of C3S and C2S, which was conducive to the generation of calcium silicate hydrate gels. Furthermore, the addition of ion chelator improved the pore-size distribution and microstructure of cement paste, and a large number of floccules and needles appeared in the pores of cement paste.

The increasing reclaimed asphalt pavement mixture causes environmental pollution and a waste of resource, which could be resolved by the asphalt recycling technology. In this paper, corn oil, waste engine oil, vacuum stream oil and cashew shell oil are used for rejuvenating aged SBS modified asphalt (ASMA), and the effect of composition, structure and thermal-oxidative stability of recycling agents on the early and long-term performance of rejuvenated binder are thoroughly investigated. The results indicate cashew shell oil with nut phenol derivatives has the best rejuvenating effect on ASMA, corn oil containing aliphatic hydrocarbons is more conducive to improving the low temperature performance of rejuvenated ASMA, and vacuum stream oil containing nonpolar alkane compound shows the worst regeneration effect. Meanwhile, simultaneous thermal analysis reveals nonpolar aliphatic hydrocarbons vacuum stream oil has the poorest thermal stability for its lowest initial decomposition temperature 146 °C, while initial decomposition temperature of cashew shell oil and corn oil are all over 200 °C. The changes of physical and rheological properties of cashew shell oil rejuvenated ASMA after aging are much smaller than that of others, which indicates cashew shell oil with excellent thermal-oxidative stability is more conductive to inhibiting the transition from viscosity to elasticity of rejuvenated binder in the aging process. While vacuum stream oil rejuvenated ASMA shows the most serious aging degree, suggesting the poor thermal-oxidative stability of recycling agents has adverse effects on the anti-aging properties of rejuvenated binder. Infrared spectrum analysis indicates the aging index growth rate of cashew shell oil rejuvenated ASMA is the smallest, also demonstrating the best aging resistance of cashew shell oil rejuvenated ASMA. The correlation coefficients between sulfoxide index and physical-rheological properties are almost all higher than 0.90, while that between sulfoxide index and physical-rheological properties are lower than 0.71, therefore sulfoxide index can be a better indicator for estimating the physical-rheological properties of rejuvenated SBS modified bitumen in the service.

A reactive rejuvenator (RR) containing epoxy functional groups and a conventional rejuvenator (CR) were used to regenerate the aged SBS modified bitumen (SBSMB). Effects of two kinds of rejuvenators on physical properties, rheological properties, chemical structure and phase morphology of the aged SBSMB were investigated. Compared with CR, RR performs better in recovering the physical and rheological properties of aged SBSMB, especially for ductility, 9 wt% RR could recover the ductility of aged SBSMB to a level which is close to virgin SBSMB, and the RR shows more effective regeneration effect in the repeated aging and regeneration. FTIR and phase morphology analysis indicates that epoxy functional groups in RR could react with carboxylic groups formed in the degradation of SBS and generate carboxylic ester group, which could bond those oxygenated chain fragments of SBS, enhance the interaction among the SBS chains and partially offset the degradation of SBS chains and the swelling and dilution effects of oily compositions on SBS, resulting in good restoration of the network structure of SBS and the ductility of SBSMB.

Two different types of UV absorbents, 2-hydroxybenzoic acid and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, were intercalated into layered double hydroxides (LDHs) to synthesize organic LDH by anion-exchange method, and then the synthesized organic LDHs were applied to modify bitumen aiming to improve UV aging resistance of bitumen. According to the characterization with X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM), the two UV absorbents were successfully intercalated into the galleries of LDH, leading to the expansion of interlayer distance of LDH. Thermogravimetry and differential scanning calorimetry (TG–DSC) and UV–vis absorbance analyses indicated that the thermal stability and UV absorptive ability of UV absorbents were enhanced significantly. Compared with LDH, organic LDH exhibited better improvement in UV aging resistance of bitumen by restraining the oxidation of bitumen and generation and stacking of asphaltenes cluster during UV exposure, which was due to the enhanced UV absorptive ability of organic LDH and compatibility between organic LDH and bitumen.

Layered double hydroxides (LDHs)/styrene-butadiene-styrene (SBS) copolymer modified bitumen was prepared by melt blending. The effect of LDHs on the ultraviolet (UV) aging behavior of SBS modified bitumen was investigated. The changes of chemical structures of modified bitumen before and after UV aging were characterized by Fourier transform infrared spectroscopy (FTIR). The results show that LDHs obviously reduce the variation of softening point and low temperature flexibility of SBS modified bitumen under different UV radiation intensities, which indicates that the UV aging resistance performance of SBS modified bitumen is improved effectively by LDHs. Compared with SBS modified bitumen, the changes of carbonyl, sulfoxide and butadienyl of LDHs/SBS modified bitumen decrease significantly after UV aging according to FTIR analysis, demonstrating that the oxidation and degradation reactions of SBS modified bitumen were restrained effectively by adding LDHs.

Organic expanded vermiculites (OEVMTs) were prepared using cetyltrimethyl ammonium bromide (CTAB) and octadecyl dimethyl benzyl ammonium chloride (ODBA) as intercalation agents. Effect of EVMT organic modification on physical and aging properties of styrene–butadiene–styrene (SBS) modified bitumen was investigated. The microstructures of the binders were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. EVMT/SBS modified bitumen forms a phase-separated structure, while OEVMT/SBS modified bitumens form the exfoliated nanostructures according to XRD analysis. OEVMTs show the more obvious influence on physical properties of SBS modified bitumen in comparison with EVMT. The compatibility between the EVMT and SBS modified bitumen is also improved after organic modification of EVMT. AFM analysis indicates that the contrast between the dispersed phase and the matrix phase in SBS modified bitumen increases with the addition of ODBA-EVMT. As a result of thin film oven test (TFOT), the viscosity aging index of SBS modified bitumen decreases, while the retained ductility and penetration increase obviously with the introduction of EVMT and OEVMTs. ODBA-EVMT/SBS modified bitumen has more pronounced improvements in aging resistance of SBS modified bitumen in comparison with CTAB-EVMT/SBS modified bitumen by preventing the phase-separated trend of the SBS modified bitumen during TFOT.

The prevention of the ultraviolet (UV) aging of styrene–butadiene–styrene (SBS)-modified bitumen is of great significance because UV aging is considered to be a critical factor in the deterioration of the performance of bituminous roads. In this study, we selected two UV absorbers (octabenzone and bumetrizole) as modifiers to evaluate their effects on the rheological and UV-aging properties of different SBS-modified bitumens (linear and radial types) by means of dynamic shear rheological testing. The thermooxidative aging of the binders was also investigated through thin-film oven testing. The results show that for the linear- and radial-SBS-modified bitumens, octabenzone only enhanced their elasticity at high temperatures, but bumetrizole could increase the elastic response at intermediate temperatures on the one hand and the viscous response at high temperatures on the other hand. The UV aging of the radial-SBS-modified bitumens could effectively be alleviated by both octabenzone and bumetrizole, whereas that of the linear ones could only be improved by bumetrizole. The influence of the UV absorbers on the thermooxidative-aging properties of the SBS-modified bitumens was dependent on the types of UV absorbers and SBS polymers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Seeking a new method to solve the ultraviolet (UV) aging of bitumen is of great importance for road applications since the UV aging is considered to be one of the main causes leading to the performance deterioration of bitumen. In this paper, two UV absorbers (octabenzone and bumetrizole) were applied to modify the bitumen by melt blending. Effect of UV aging on rheology, chemistry and morphology of the UV absorber modified bitumens was investigated, by means of dynamic shear rheometer, thin-layer chromatography with flame ionization detection, Fourier transform infrared spectroscopy and atomic force microscopy, to reveal the mechanisms of action for bitumen and UV absorbers. Results show that the two UV absorbers show opposite influences on the UV aging performance of bitumen depending on the type of UV absorbers. The bumetrizole improves the UV aging resistance of bitumen remarkably since the bumetrizole can inhibit reactions of aromatization and oxidation of bitumen molecules to a certain extent during the UV aging, and thus slows down the rate at which the bitumen transforms from sol to gel. The bumetrizole modified bitumen has the potential to be used in pavement for improvement of the UV aging resistance during service life.

Effect of aging on the morphology of bitumen was investigated. Two bitumens were aged according to the thin film oven test (TFOT), pressure aging vessel (PAV) test and ultraviolet (UV) radiation, respectively. The morphology of the binders before and after aging was characterized by atomic force microscopy. The physical properties and chemical compositions of the binders were also measured. The results showed that aging affected the bitumen morphology significantly. Aging increased the overall surface stiffness of the bitumen and made the bitumen surface more solid-like. The extent of these changes was dependent on aging conditions. TFOT decreased the contrast between the dispersed domains and the matrix, which contributed to the single-phase trend of the binders. The effect of PAV aging on morphology of the binders was dependent on the base bitumen. In one case, it further accelerated the single-phase trend of bitumen in comparison with that after TFOT. In the other case, it caused the phase separation of bitumen. In both cases, PAV aging increased the surface roughness of the binders obviously. As a result of UV aging, the contrast between the matrix phase and dispersed phase was increased due to the difference in sensitivity to UV radiation of the bitumen molecules, which caused or further promoted the phase separation in the binders. Regardless of the aging procedure carried out, a strong correlation was observed between the changes in morphology and physical properties as well as chemical compositions of the binders before and after aging.

Organo-montmorillonite(OMMT)/Styrene-butadiene-styrene(SBS) modified bitumen nanocomposites were prepared by melt blending. The microstructures of OMMT/SBS modified bitumen were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM), respectively. The effect of OMMT on ultraviolet (UV) aging properties of SBS modified bitumen was investigated. FTIR and XRD analyses indicate that the OMMT/SBS modified bitumen forms an intercalated structure. It is observed that the phase contrast between the dispersed domains and the matrix is inverted in SBS modified bitumen, which is decreased with the introduction of OMMT according to AFM analysis. As a result of UV aging, both viscosity aging index and softening point increment of OMMT/SBS modified bitumen decrease significantly. There is a single phase trend in the morphology of the bitumen after aging, which is accelerated by the existence of SBS. However, these changes can be effectively prevented under the influence of OMMT, indicating the good UV aging resistance of OMMT/SBS modified bitumen.

The effect of montmorillonite (MMT) organic modification on microstructures and ultraviolet (UV) aging properties of bitumen was investigated. The microstructures of MMT modified bitumen were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM), respectively. The binders were aged by UV radiation. The UV aging properties of MMT modified bitumen was studied by determining physical properties and AFM analysis. XRD and FTIR analyses show that the sodium montmorillonite (Na(+) -MMT) modified bitumen forms a phase-separated structure, whereas the organo-montmorillonite (OMMT) modified bitumen forms an intercalated structure. After Na(+) -MMT modification, the contrast between the matrix and the dispersed domains is inverted according to AFM analysis. However, this contrast inversion is prevented with the introduction of OMMT due to the good compatibility between the OMMT and the bitumen. As a result of UV aging, both viscosity aging index and softening point increment of OMMT modified bitumen are lower than that of the unmodified bitumen and Na(+) -MMT modified bitumen. Furthermore, the association interactions and single-phase trend in OMMT modified bitumen are further prevented in comparison with Na(+) -MMT modified bitumen during UV aging, indicating the good aging resistance of OMMT modified bitumen after organic modification of MMT.

The modified asphalt binders with hindered phenolic antioxidant (Irganox 1010) were prepared by melt blending, and the effects of Irganox 1010 on physical and rheological properties of base asphalt were investigated by means of conventional physical properties tests and dynamic shear rheometer (DSR) tests. The short-term and long-term thermo-oxidative aging properties of asphalts with Irganox 1010 were studied by thin-film oven test (TFOT) and pressure aging vessel (PAV) test. The influence of Irganox 1010 on the chemical structure and compositions of asphalt before and after the aging test were evaluated using Fourier transform infrared spectroscopy (FTIR) analysis and thin-layer chromatography with flame ionization detection (TLC-FID) analysis, respectively. The results show that the penetration and ductility are increased, whereas the viscosity and softening point are decreased, with the addition of Irganox 1010, and Irganox 1010 also decreases the complex modulus and increases the phase angle of asphalt binder. The antioxidant-treated binders exhibit excellent resistance to thermo-oxidative aging. Furthermore, Irganox 1010 inhibits the carbonyl (at 1,700 cm−1) index and sulfoxide (at 1,035 cm−1) index increment by oxidation of phenolic hydroxyl and degradation of ester group, and changes of chemical compositions of asphalt show that Irganox 1010 peptizes the asphaltenes and exhibits effective inhibition of gelatinization of asphalt binder during the process of thermal oxidation aging.

High dielectric constant and low loss ceramics in the system Ba4LaTiNb3−x Ta x O15 (x = 0–3) have been prepared by conventional solid-state ceramic route. Ba4LaTiNb3−x Ta x O15 solid solutions adopted A5B4O15 cation-deficient hexagonal perovskite structure for all compositions. The materials were characterized at microwave frequencies. They show a linear variation of dielectric properties with the value of x. Their dielectric constant varies from 53.1 to 42.3, quality factor Qu × f from 18,790 to 28,070 GHz and temperature variation of resonant frequency from +94.3 to +33.1 ppm/°C as the value of x increases.

Tri-block copolymer styrene–butadiene (SBS) is extensively applied in bituminous highway construction due to its high elasticity and excellent weather resistance. With the extension of time, tri-block structural SBS automatically degrades into bi-block structural SB- with some terminal oxygen-containing groups under the comprehensive effects of light, heat, oxygen, etc. In this paper, the effects of aging temperature, aging time and oxygen concentration on the molecular structure of thermo-oxidative aged SBS were mainly investigated using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), and the correlation between oxygen-containing groups and thermal properties (TG–DTG) was further discussed. The FTIR and XPS results show that rapid decomposition of SBS will occur with increments of aging temperature, aging time and oxygen concentration, and a large number of oxygen-containing groups such as –OH, C=O, –COOH, etc. will be formed during thermo-oxidative aging. In short-term aging, changes in aging temperature and oxygen concentration have a significant impact on the structural damage of SBS. However, in long-term aging, it has no further effect on the molecular structure of SBS or on increasing oxygen concentration. The TG and DTG results indicate that the concentration of substances with low molecular weight gradually increases with the improvement of the degree of aging of the SBS, while the initial decomposition rate increases at the beginning of thermal weightlessness and the decomposition rate slows down in comparison with neat SBS. From the relation between the XPS and TG results, it can be seen that the initial thermal stability of SBS rapidly reduces as the relative concentration of the oxygen-containing groups accumulates around 3%, while the maximum decomposition temperature slowly decreases when the relative concentration of the oxygen-containing groups is more than 3%, due to the difficult damage to strong bonds on the molecular structure of aged SBS.

Aging behavior and thermal stability of styrene-butadiene-styrene tri-block copolymer (SBS) in blends were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and thermo-gravimetric analysis (TG). From the analysis of FTIR, the alcohol and carboxyl hydroxyl groups will be gradually generated during the thermal and ultraviolet aging, and the effect of short-term high temperature is more serious than longterm ultraviolet exposure on the structure of SBS; XPS results show that oxygen/carbon ratio of thermal and ultraviolet aged SBS have significantly increased, while the relative concentration of C-O-H(R) is far higher than that of COOH(R); inferred oxidation mechanism of SBS based on the analytical results of FTIR and XPS shows alcohol, carboxyl, ether, ketone, etc. have mainly formed in blends after thermal or ultraviolet aging; moreover, on account of the distribution index of carbon-oxygen binding state of thermal and ultraviolet aged SBS(respectively 3.15 and 1.28), C-O is easily produced than C=O and the effect of thermal aging is more obvious; from the results of TG, the maximum decomposition rate and temperature decrease after aging.

By means of the Laplace transform and a series expansion, exact solutions of the bound state for the one-dimensional Schrodinger equation with a potential -Ze2/x are given. We found that the energy levels are proportional to 1/n2 (n = 1,2,3,...) and the value of the wavefunction of the bound state at the origin is zero. The reasons for the wrong answer that the energy levels are proportional to (n + ½)-2 with n an integer are analysed.

Trusted computing technology can establish trust in the local computer platform by a trusted boot, and can further transfer the trust to a remote verifier through a remote attestation mechanism. However, no standard solution is provided to convey the trust information to users in a friendly manner. Existing methods have no implementation, or need users to buy a specific USB device (an additional purchasing burden for users). To establish user-based trust, we summarize possible solutions and classify the related works according to each solution. After comparing these solutions, we provide a better method “Mobile Trusted Agent (MTA)”, which uses a general mobile device as a reliable medium to establish a secure channel between the local user and the remote verifier. Finally, we have implemented MTA using an ARM SoC device and evaluated the performance of the protocol for secure channel. The evaluation results demonstrate that MTA has high quality and flexibility for building user-based trust.