Energy-Trapping Characteristics of Lateral Field Excited GdCOB Crystal Bulk Acoustic Wave Devices Based on Stepped Electrodes.

In this work, high-frequency forced vibrations of lateral field excitation (LFE) devices with stepped electrodes based on monoclinic crystals GdCOB are modeled, and the influence laws of the device parameters (the step number, size, and thickness of the stepped electrodes) on the energy-trapping effects of the device are revealed. The results show that the step number has a significant effect on the energy-trapping effect of the device: with the increase in the step number, the stronger energy-trapping effect of the device can be obtained; with the increase in the thickness difference of two layers of electrodes, the energy-trapping effect of the device becomes stronger; with the increase in the difference of the electrode radius, the energy-trapping effect of the device is enhanced gradually. The results of this work can provide an important theoretical basis for the design of stepped-electrode LFE resonators and sensors with high-quality factors based on monoclinic crystals.

Pure- and Pseudo-Lateral-Field-Excitation Characteristics of Relaxor Ferroelectric Single Crystal PMN-PT.

The relaxor ferroelectric single crystal (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) has high piezoelectric constants, and thus has a good application prospect in the field of highly sensitive piezoelectric sensors. In this paper, for relaxor ferroelectric single crystal PMN-PT, the bulk acoustic wave characteristics on pure- and pseudo-lateral-field-excitation (pure- and pseudo-LFE) modes are investigated. LFE piezoelectric coupling coefficients and acoustic wave phase velocities for PMN-PT crystals in different cuts and electric field directions are calculated. On this basis, the optimal cuts of pure-LFE and pseudo-LFE modes of relaxor ferroelectric single crystal PMN-PT are obtained, namely, (zxt)45° and (zxtl)90°/90°, respectively. Finally, finite element simulations are carried out to verify the cuts of pure-LFE and pseudo-LFE modes. The simulation results show that the PMN-PT acoustic wave devices in pure-LFE mode have good energy-trapping effects. For PMN-PT acoustic wave devices in pseudo-LFE mode, when the device is in air, no obvious energy-trapping emerges; when the water (as a virtual electrode) is added to the surface of the crystal plate, an obvious resonance peak and the energy-trapping effect appears. Therefore, the PMN-PT pure-LFE device is suitable for gas-phase detections. While the PMN-PT pseudo-LFE device is suitable for liquid-phase detections. The above results verify the correctness of the cuts of the two modes. The research results provide an important basis for the development of highly sensitive LFE piezoelectric sensors based on relaxor ferroelectric single crystal PMN-PT.

Effect of minute amounts of arsenic on the sulfamethoxazole removal and microbial community structure via the SBR system.

In this study, the effect of arsenic on the sulfamethoxazole (SMX) removal efficiency and microbial community structure was investigated over 60 days using the SBR process. The results showed that the presence of arsenic had no significant impact on the system performance, the removal efficiencies of two reactors, R1 (the control test) and R2 (with the addition of arsenic), were 13.36 ± 5.71 and 14.20 ± 5.27%, which were attributed to the adsorption of SMX by fulvic acid-like substances and tryptophan-like proteins of extracellular polymeric substances. Compared to the seed sludge, the species number indicated that R2 possessed the richer diversity, while R1 possessed the lower diversity on day 60, which might be relative to the transferring of antibiotic resistance genes (ARGs) in sludge bacterial communities; the minute amounts of arsenic could make the relative levels of Sul1 and Sul2 genes which encode ARGs of sulfonamides in R2 (2.07 and 2.47%) be higher than that in R1 (1.65 and 1.27%), which made the bacterial community of the R2 system more adaptable to SMX stress. Therefore, the minute amounts of arsenic weakened the effect of SMX on the system and enhanced the stability of the microbial community structure.

Stability and nutrients removal performance of a Phanerochaete chrysosporium-based aerobic granular sludge process by step-feeding and multi A/O conditions.

A Phanerochaete chrysosporium-based aerobic granular sludge (PC-AGS) was developed by inoculating fungal mycelial pellets into a lab-scale aerobic granular sequencing batch reactor (AGSBR). A strategy using step-anaerobic feeding coupled with multi A/O conditions was adopted. The results showed that the removal efficiencies for total phosphorus (TP) and total inorganic nitrogen (TIN) were 94.56 ± 2.92% and 75.20 ± 7.74%, respectively, under relatively low aeration time. Compared with original AGS, the content of extracellular proteins for PC-AGS obviously increased from 18.61 to 41.44 mg/g MLSS by the end of phase I. Moreover, the mature granules had a larger size and better stability during the 100 days operation. Furthermore, the analysis of microbial diversity detected many key functional groups in PC-AGS granules that were beneficial to nutrients removal. This work demonstrated that the addition of fungal pellets not only enhanced the removal performance, but also improved the stability of the AGS system.

Morphological and molecular features of some freshwater prawn species under genus Macrobrachium Spence Bate, 1868 (Crustacea: Decapoda: Palaemonidae) from Myanmar.

Myanmar is abundant in lakes and rivers, yet only a few investigations on the fauna of shrimps and prawns have been conducted and no molecular characteristics of prawn species have been described. This study reveals the morphologically identification of five freshwater prawn species under the genus Macrobrachium, including M. cavernicola, M. australiense, M. johnsoni, M. josephi and Macrobrachium sp.WMY-2017. As there was no previous record and information concerning with M. australiense, M. johnsoni, M. josephi and Macrobrachium sp. WMY-2017, they were regarded as the first record from Myanmar. A fragment of Mitochondrial Cytochrome Oxidase I Gene (COI) was amplified successfully from three studied species: M. australiense, M. josephi, and Macrobrachium sp.WMY-2017. The interspecific divergences of studied species varied from 0.01 to 0.15. The phylogenetic tree based on COI fragment sequences showed that M. australiense was closely related to M. rosenbergii, while Macrobrachium sp. WMY-2017 was closest to M. josephi. The results of molecular phylogeny has clarified the relationship within the genus Macrobrachium and represents the first step toward understanding the pattern of speciation base on molecular approach in Myanmar.

The Effects of Natural Chinese Medicine Aconite Root, Dried Ginger Rhizome, and Coptis on Rectal and Skin Temperatures at Acupuncture Points.

The 4 properties of Chinese materia medica refer to cold, hot, warm, and cool. In the present study, the effects of the Coptis, the prepared aconite root, and dried ginger rhizome were compared with regard to the rectal and skin temperature changes of the related body surface acupuncture points (Dazhui, Zhiyang, Mingmen, Zhongwan, and Shenque). The investigation aimed to explore the thermal sensitive points, which can reflect the cold and hot properties of the Chinese herbs. This study showed that the prepared aconite root and dried ginger rhizome exhibited a warming effect on the body temperature, whereas the warming sensitive points were Zhongwan, Shenque, Dazhui, and Zhiyang. Coptis exhibited both a warming and a cooling effect on the body temperature, and the cooling sensitive point was Dazhui. The concomitant effect of these three Chinese herbs on the regulation of the body temperature was reflected by Dazhui. However, there are still some limitations and one-sidedness. For instance, the cold and hot property of some herbs cannot be fully reflected through relevant acupoints on the conception and governor vessels. More detecting sites such as ears and internal organs will be selected for further exploration of Chinese herbs' cold and hot property.