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The Marshall method is today considered the standard method of asphalt mixture design for practical engineering applications. By using this method, engineering designers reap the benefits of its easy implementation and inexpensive equipment requirements. However, the Marshall method also has shortcomings and limitations, such as the difficulty in simulating the actual working conditions of a road under heavy load. Therefore, it is desirable to develop alternative methods for designing asphalt mixtures that can simulate the actual conditions under which the road will be used and so enable technically superior road construction. The emergence of the gyratory testing machine (GTM) method represents a new direction in asphalt mixture design that could plan more effectively for heavy loads in a hot and humid environment. In this paper, the two design methods are compared on the basis of the oil-stone ratio, high-temperature stability, water stability, and rutting resistance of the mixes they recommend. We put forward an improved GTM method suitable for the high temperatures and heavy traffic in Guangdong Province. This work provides a foundation for the large-scale popularization and application of the GTM method.

We described a new and sensitive method for the determination of mercury ions (Hg2+) on the basis of fluorescence correlation spectroscopy (FCS) and recognition of oligonucleotides. In this assay, 30-nm gold nanoparticles (GNPs) were modified with oligonucleotides containing thymine bases (T) as fluorescent probes, and the principle of this assay was based on the specific binding of Hg2+ by two DNA thymine bases. When two GNPs labelled with different oligonucleotides were mixed with a sample containing Hg2+, the T-Hg2+-T binding reaction should cause GNPs to form dimers (or oligomers), which would lead to a significant increase in the characteristic diffusion time of GNPs in the detection volume. The FCS method is a single molecule detection method and can sensitively detect the change in the characteristic diffusion time of GNPs before and after binding reactions. The quantitative analysis was performed according to the relation between the change in the characteristic diffusion time of GNPs and the concentration of Hg2+. Under optimal conditions, the linear range of this method was from 0.3 nM to 100 nM, and the detection limit was 0.14 nM for Hg2+. This new method was successfully applied for direct determination of Hg2+ levels in water and cosmetics samples. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, we report for the first time a one-pot approach for the synthesis of new CdSeTeS quaternary-alloyed quantum dots (QDs) in aqueous phase by microwave irradiation. CdCl2 was used as a Cd precursor during synthesis, NaHTe and NaHSe were used as Te and Se precursors and mercaptopropionic acid (MPA) was used as a stabilizer and source of sulfur. A series of quaternary-alloyed QDs of different sizes were prepared. CdSeTeS QDs exhibited a wide emission range from 549 to 709 nm and high quantum yield (QY) up to 57.7 %. Most importantly, the quaternary-alloyed QDs possessed significantly long fluorescence lifetimes > 100 ns as well as excellent photostability. Results of high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX) and powder X-ray diffraction (XRD) spectroscopy showed that the nanocrystals possessed a quaternary alloy structure with good crystallinity. Fluorescence correlation spectroscopy (FCS) showed that QDs possessed good water solubility and monodispersity in aqueous solution. Furthermore, CdSeTeS QDs were modified with alpha-thio-omega-carboxy poly(ethylene glycol) (HS-PEG-COOH) and the modified QDs were linked to anti-epidermal growth factor receptor (EGFR) antibodies. QDs with the EGFR antibodies as labeling probes were successfully applied to targeted imaging for EGFR on the surface of SiHa cervical cancer cells. We believe that CdSeTeS QDs can become useful probes for in vivo targeted imaging and clinical diagnosis. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We described a new and sensitive method for the determination of mercury ions (Hg(2+) ) on the basis of fluorescence correlation spectroscopy (FCS) and recognition of oligonucleotides. In this assay, 30-nm gold nanoparticles (GNPs) were modified with oligonucleotides containing thymine bases (T) as fluorescent probes, and the principle of this assay was based on the specific binding of Hg(2+) by two DNA thymine bases. When two GNPs labelled with different oligonucleotides were mixed with a sample containing Hg(2+), the T-Hg(2+)-T binding reaction should cause GNPs to form dimers (or oligomers), which would lead to a significant increase in the characteristic diffusion time of GNPs in the detection volume. The FCS method is a single molecule detection method and can sensitively detect the change in the characteristic diffusion time of GNPs before and after binding reactions. The quantitative analysis was performed according to the relation between the change in the characteristic diffusion time of GNPs and the concentration of Hg(2+). Under optimal conditions, the linear range of this method was from 0.3 nM to 100 nM, and the detection limit was 0.14 nM for Hg(2+). This new method was successfully applied for direct determination of Hg(2+) levels in water and cosmetics samples., (Copyright © 2014 John Wiley & Sons, Ltd.)

In this study, we report for the first time a one-pot approach for the synthesis of new CdSeTeS quaternary-alloyed quantum dots (QDs) in aqueous phase by microwave irradiation. CdCl2 was used as a Cd precursor during synthesis, NaHTe and NaHSe were used as Te and Se precursors and mercaptopropionic acid (MPA) was used as a stabilizer and source of sulfur. A series of quaternary-alloyed QDs of different sizes were prepared. CdSeTeS QDs exhibited a wide emission range from 549 to 709 nm and high quantum yield (QY) up to 57.7 %. Most importantly, the quaternary-alloyed QDs possessed significantly long fluorescence lifetimes > 100 ns as well as excellent photostability. Results of high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX) and powder X-ray diffraction (XRD) spectroscopy showed that the nanocrystals possessed a quaternary alloy structure with good crystallinity. Fluorescence correlation spectroscopy (FCS) showed that QDs possessed good water solubility and monodispersity in aqueous solution. Furthermore, CdSeTeS QDs were modified with alpha-thio-omega-carboxy poly(ethylene glycol) (HS-PEG-COOH) and the modified QDs were linked to anti-epidermal growth factor receptor (EGFR) antibodies. QDs with the EGFR antibodies as labeling probes were successfully applied to targeted imaging for EGFR on the surface of SiHa cervical cancer cells. We believe that CdSeTeS QDs can become useful probes for in vivo targeted imaging and clinical diagnosis., (Copyright © 2012 John Wiley & Sons, Ltd.)